0001]The present invention, by hot forging crankshaft for 3-cylinder engine (hereinafter, also referred to as "forged crankshaft") it relates to a technology for producing. In particular, three cylinders including in the manufacturing process of the forged crankshaft, molding apparatus for molding a material for out finishing subjected to finishing strike to shape the final shape of the forged crankshaft, and a preliminary molding step using the molding device the method of manufacturing a forged crankshaft engine.
BACKGROUND
[0002]
　It began passenger, in the engine, such as motorcycles and agricultural machinery, require crankshaft to retrieve power by converting the reciprocating motion of the piston into rotary motion. Crankshaft, and those manufactured by forging, but are roughly divided into those produced by casting, dominant former forged crankshaft strength and rigidity are often used. In recent years, because of the response to enhance the emission control fuel efficiency, has accelerated the engine capacity of downsizing, 3-cylinder engine has attracted attention.
[0003]
　Generally, forging crankshaft for 3-cylinder engine, cross section and the raw material cross-sectional area constant billet over the entire length in the round or square, is produced through preformed die forging, the steps of burr punching and shaping in order . Preforming step includes the steps of clinching the roll forming (also referred to as called "push flat"), the mold forging step includes the steps of rough hitting the finishing strike.
[0004]
　Figure 1 is a schematic diagram for explaining a conventional typical three-cylinder engine forged crankshaft manufacturing process. Crankshaft 1 illustrated in the drawing, 3 is intended to be mounted on cylinder engine, four journal portions J1 ~ J4,3 one pin portions P1 ~ P3, the front portion Fr, flanges Fl, and journal portion J1 ~ six crank arm connecting the J4 and pin P1 ~ P3 each consists (hereinafter, simply referred to as "arm") A1 ~ A6, among six arm portions A1 ~ A6, the first ends, first lead to the third pin portion P1, P3, the second arm portions A1, A2, and the fifth is a crankshaft of the 3-cylinder -4 Like counterweight having a balance weight to the sixth arm portion A5, A6. Hereinafter, when collectively each journal portion J1 ~ J4, pin P1 ~ P3, and the arm portions A1 ~ A6, the sign, in the journal portion "J", a pin portion "P", "A" in the arm portion It referred to as.
[0005]
　In the manufacturing method shown in FIG. 1, forged crankshaft 1 is manufactured as follows. First, after heating in advance by the induction heating furnace or gas heating furnace billet 2 shown in FIG. 1 cut to a predetermined length (a), performing roll forming. The roll forming process, for example, while squeezing and rolling a billet 2 by grooved roll allocate its volume in the longitudinal direction, forming a roll wasteland 103 as the intermediate material (see Figure 1 (b)). Next, in the bending beating process, the roll wasteland 103 obtained by roll forming longitudinally and partially by pressing pressure from the direction perpendicular to allocate its volume, forming the bending wasteland 104 becomes further intermediate material ( FIG. 1 (c) refer).
[0006]
　Subsequently, the rough beating step, bending and press forging using a pair of molds and the resulting bent wasteland 104 up and down by beating, forging 105 the approximate shape are shaped in a crank shaft (final forged product) molding (refer to FIG. 1 (d)). Furthermore, the finishing beating step is subjected is rough forged material 105 obtained by rough beating, rough forging material 105 pressed forging using a pair of dies vertically, shaped to conform to the crankshaft is shaped forged molding a timber 106 (see FIG. 1 (e)). When these rough beating and finishing beating, from between the parting surface of the mold facing each other, excess material flows out as a burr. Therefore, rough forged material 105, finish forged material 106, respectively burr 105a around the shaped crank shaft, 106a are attached increases.
[0007]
　The burr punching process, while maintaining the mold the finish forged material 106 with the burr 106a obtained by finishing beating from above and below, to remove punching burrs 106a by blade type. Thus, as shown in FIG. 1 (f), forged crankshaft 1 can be obtained. The shaping step, the key point of the forged crankshaft 1 removing the burr, for example, the journal portion J, the pin portion P, the front portion Fr, the shaft portion such as a flange portion Fl, in mold arm A from above and below in some cases slightly to press, to correct to the desired size and shape. Thus, forged crankshaft 1 is manufactured.
[0008]
　Manufacturing process shown in FIG. 1 is not limited to the crank shaft of the three-cylinder -4 Like counterweight illustrated, a crankshaft of the three cylinders -6 Like counterweight having a balance weight for all six of the arm portion A also, it is the same. Incidentally, when the adjustment of the arrangement angle of the pin portion is required, after the burr punching process, twisting process is added.
[0009]
　Incidentally, in this manufacturing method, since an unnecessary burr not a product is produced in large quantities, undeniable decrease in yield. Therefore, in producing forged crankshaft, conventionally, minimizing the occurrence of burrs, is possible to achieve improvement in yield has become an issue of paramount. The prior art for this problem is the following.
[0010]
　For example, Patent Document 1, the crank shaft portion corresponding to the journal portion and the pin portion is a material round rod of stepped constricted individually a pair sandwiching the pin portion corresponding parts journal portion corresponding parts, respectively held by the die, the polarization in this state, along with providing the compressive deformation into a round bar stock is brought closer to both die in the axial direction, against the punch in the pin portion corresponding parts in the axial direction and a direction perpendicular to the pin portion corresponding parts is the core, by repeating this sequential across all crank throw, is shaped journal portion and the pin portion, a technique for producing a crankshaft arm portions also be shaped as such is disclosed.
[0011]
　Further, Patent Document 2, a simple round bar as a material, while fixed to one of the ends of the round bar material holds each other of movable type, the journal portion corresponding portions of the round bar material the journal type, respectively hold the pin corresponding parts in the pin type, from this state, the movable mold and is moved in the axial direction toward the fixed journal type and pin type applies compressive deformation into a round bar stock At the same time, by eccentric pin portion corresponding parts to move the pin-type axially perpendicular direction of eccentricity, is shaped journal portion and the pin portion, to produce the crankshaft arm portions also be shaped as such techniques have been disclosed.
[0012]
　In the technique disclosed in Patent Documents 1 and 2, since the both burr is not generated, it can be expected a significant improvement in yield.
CITATION
Patent Document
[0013]
Patent Document 1: JP 2008-155275 Patent Publication
Patent Document 2: JP 2011-161496 JP
Summary of the Invention
Problems that the Invention is to Solve
[0014]
　As described above, the techniques disclosed in Patent Documents 1 and 2 is for forming the material of the rod suddenly the crankshaft shape. However, forged crankshaft so high strength and high rigidity is required, the material is difficult to deform. Therefore, the crankshaft that can actually be produced, thicker the thickness of the arm portion, eccentricity of the pin portion is also forced to not give become small, are limited to relatively slow crankshaft shape. Moreover, the shape of the arm portion, is limited to the simple no balance weight all.
[0015]
　Further, in the technique disclosed in the Patent Documents 1 and 2, the arm portion includes a free expansion in the axial direction and a direction perpendicular with the compressive deformation in the axial direction of the round bar material, the pin portion corresponding portions of the round bar material It is shaped by the eccentricity move in accompanying tensile deformation. Thus, the contour shape of the arm portions tend to be irregular, it can not be secured dimensional accuracy.
[0016]
　The present invention has been made in view of the above problems, forged crankshaft good yield for 3-cylinder engine, moreover, in order to manufacture with high dimensional accuracy regardless of its shape, the production of forged crankshaft in the process, the final shape assumed by performing finish beating of shaping the, and to provide a molding apparatus for molding materials for out finishing subjected to the finishing strike. Another object of the present invention may yield a forged crankshaft for 3-cylinder engine, moreover, it is to provide a production method capable of producing with high dimensional accuracy regardless of its shape.
Means for Solving the Problems
[0017]
　The present invention for solving the above problems, 3 shown below (1) and the molding device of the three-cylinder material for out finishing of engine forged crankshaft shown in (2), as well as the following (3) to (6) and gist a method for manufacturing a forged crankshaft for cylinder engine.
[0018]
　Forming apparatus according to an embodiment of the present invention is a three-cylinder in the process of producing the forged crankshaft for an engine, an apparatus for forming a material for out finishing subjected to finishing strike to shape the final shape of the forged crankshaft ,
　of the journal portion and the axial direction of the forged crankshaft same rough journal portion length, the pin portion and the axial length is the same coarse pin portion of the forged crankshaft, and the forged crankshaft in the axial direction than the crank arm from a crude material which is thicker rough crank arm is shaped respectively, a device for forming a material for out finishing comprises the following arrangement.
[0019]
　(1) Crude pin portion of the crude material, eccentricity of the axial perpendicular direction is smaller than the eccentricity of the pin portion of the forged crankshaft,
　molding apparatus according to an embodiment of the present invention comprises a reference pin type below, the movable pin type, a journal type, the.
　Reference pin type is disposed at a position of one coarse pin portions of the rough pin, with addressed cracking in the coarse pin, while in contact with the side surface of the rough crank arm portion leading to the rough pin portion, the shaft It is constrained to move in the direction to move axially perpendicular direction.
　Movable pin type, the reference pin-type is disposed on the coarse pin portion of each position other than crude pin portion destined to crack, the conjunction addressed to divide the coarse pin respectively, each said crude to the pin portion leading crude crank arm while contact a side surface, moves in the axial direction and the axial direction perpendicular to a direction toward the reference pin type.
　Journal type is disposed in rough journal portions of each position, the rough journal portions individually holds sandwich the axial direction and perpendicular, in contact with the side surface of the rough crank arm portion, each leading to the rough journal while being moved in the axial direction toward the reference pin type.
　The molding apparatus, a crude journal portion held sandwiched in the journal-type, the reference pin-type and movable pin type from destined wants state to the rough pin moves the journaled axially movable pin type At the same time it is moved while moving in the axial direction in the axial direction and perpendicular direction by moving the reference pin-type axially perpendicular direction, clamping pressure and forged crank its thickness crude crank arm portion in the axial direction together is reduced to a thickness of the crank arm portion of the shaft, a structure to increase its eccentricity crude pin portion is pressed against the axially perpendicular direction to the eccentricity of the pin portion of the forged crankshaft.
[0020]
　In the molding apparatus of the above (1), the reference pin-type and the movable pin type, wherein the side on which the reference pin-type and the movable pin mold was We have addressed in the rough pin portion respectively disposed outside the opposite includes an auxiliary pin-type, the journal-type, and the moves to an auxiliary pin-type axial direction forming the movable pin type and the movable pin type paired with the journal-type, the reference pin-type, after clearance between the movable pin type and the auxiliary pin type is closed, so that the rough pin portion for pressing deformation reaches the auxiliary pin-type, the movement in the axial direction perpendicular to the direction of the pin-type it is preferable that the controlled configurations.
[0021]
　In this molding apparatus, is taken as 100% the total distance traveled in the axial direction perpendicular to the direction of the reference pin-type and the movable pin type to move in the axial direction of the journal-type adjacent to the pin-type Upon completion, the moving distance in the axial direction perpendicular to the direction of the pin type is not more than 90% of the total distance traveled, and the movement is completed structure in the axial direction perpendicular to the direction of the pin type after this it is preferable to.
[0022]
　Further, in the molding apparatus of the above (1), the reference pin-type, the movable pin type and the journal type is mounted axially perpendicular direction to allow pressure press machine along the direction, the press with the reduction of the machine, along with the journal type holds sandwich the crude journal portion, the reference pin-type and the movable pin type addressed to cracking in the coarse pin, to continue the reduction of the press as it with the same time when the journal type is moved in the axial direction by individually wedge mechanism, along with the movement of the journal type, it can be configured to the movable pin type individually moving in the axial direction.
[0023]
　In this molding apparatus, differ from each other is preferable in each wedge angle of the wedge mechanism of the journal type. Further, the reference pin-type and the movable pin type is connected to the hydraulic cylinder, it is preferable to adopt a configuration that moves by driving of the hydraulic cylinder in the axial direction and perpendicular.
[0024]
　(2) Of the crude pin portion of the crude material, the first ends, third coarse pin portion, the eccentricity of the pin portion of the forged crankshaft in the axial direction and amount of eccentricity perpendicular directions opposite to each other √3 / 2 is smaller than the second roughness pin portion of the central, forging eccentricity of the axial direction perpendicular zero or first, direction perpendicular to the eccentric direction of the third coarse pin portion, are the same as the eccentricity of the pin portion of the crank shaft,
　the molding apparatus according to an embodiment of the present invention comprises a reference pin type below, the movable pin type, a journal type, the.
　Reference pin type is disposed at a position of the second coarse pin portion, the conjunction addressed to divide the coarse pin, while in contact with the side surface of the rough crank arm portion leading to the rough pin portion is constrained to movement in the axial direction ing.
　Movable pin type, first, is disposed in the third coarse pins of each position, the addressed cracking each said coarse pin, while each in contact with the side surface of the rough crank arm portion leading to the rough pin portion, moves in the axial direction and the axial direction perpendicular to a direction toward the reference pin type.
　Journal type is disposed in rough journal portions of each position, the rough journal portions individually holds sandwich the axial direction and perpendicular, in contact with the side surface of the rough crank arm portion, each leading to the rough journal while being moved in the axial direction toward the reference pin type.
　The molding apparatus, a crude journal portion held sandwiched in the journal-type, the reference pin-type and movable pin type from destined wants state to the rough pin moves the journaled axially movable pin type by moving while moving in the axial direction in the axial direction and perpendicular, with reducing its thickness to a thickness of the crank arm portion of the forged crankshaft crude crank arm portion nipped in the axial direction, the first, second 3 is a configuration that increases the roughness pin portion to √3 / 2 of the eccentricity of the pin portion of the forged crankshaft its eccentricity is pressed in opposite directions to each other in the axial direction perpendicular to the direction.
[0025]
　(3) A 3 method of manufacturing a forged crankshaft for cylinders engine, including first preforming step described below, the second preforming step, and the finishing beating process, a series of steps.
　First preforming step, as the crude material to be subjected to molding apparatus of the above (1), of the rough pin portion, the first ends, third coarse pin portion, eccentricity of the axial direction perpendicular There is in the opposite direction the same as √3 / 2 of the eccentricity of the pin portion of the forged crankshaft to each other, the second coarse pin portion of the central, axial and amount of eccentricity perpendicular first, third shaping the crude material that is smaller than the eccentricity of the pin portion of the forged crankshaft in a direction perpendicular to the eccentric direction of the rough pin portion.
　Second preforming step, using the molding apparatus according to (1), as the finishing out for material, the final shape of the forged crankshaft including an arrangement angle of the pin portion is molded materials for striking finish which is shaped .
　Finish beating process is to strike the finishing material for the finishing out, the final shape of the forged crankshaft including an arrangement angle of the pin portion is molded finish that is shaped.
[0026]
　(4) A 3 method of manufacturing a forged crankshaft for cylinders engine, including first preforming step described below, the second preforming step, finishing beating process, and twisting process, a series of steps.
　First preforming step, as the crude material to be subjected to molding apparatus of the above (1), of the rough pin portion, the first ends, third coarse pin portion, eccentricity of the axial direction perpendicular There are smaller than eccentricity of the pin portion of the forged crankshaft in the same direction, the center of the second coarse pin portion, eccentricity is first axial direction perpendicular, eccentricity of the third coarse pin portion shaping the crude material that is smaller than the eccentricity of the pin portion of the forged crankshaft in the opposite direction to the direction.
　Second preforming step, using a molding apparatus of the above (1), as the finishing out for material, the final shape of the forged crankshaft except placement angle of the pin portion is molded materials for striking finish that is shaped.
　Finish beating process is to strike the finishing material for the finishing out, the final shape of the forged crankshaft except placement angle of the pin portion is molded finish that is shaped.
　Twisting step, it adjusts the arrangement angle of the pin portion of the finish to the arrangement angle of the pin portion of the forged crankshaft.
[0027]
　(5) A 3 method of manufacturing a forged crankshaft for cylinders engine, including first preforming step described below, the second preforming step, and the finishing beating process, a series of steps.
　First preforming step, as the crude material to be subjected to molding apparatus of the above (2), of the rough pin portion, the first ends, third coarse pin portion, eccentricity of the axial direction perpendicular crude but is smaller than the eccentricity of √3 / 2 of the pin portion of the forged crankshaft in directions opposite to each other, the second coarse pin portion of the central, the eccentricity of the axial perpendicular direction is zero shaping the material.
　Second preforming step, using a molding apparatus of the above (2), as the finishing out for materials, of the crude pin portion, the first ends, third coarse pin portion, an axial direction perpendicular eccentricity amount is in the opposite direction the same as √3 / 2 of the eccentricity of the pin portion of the forged crankshaft to each other, the second coarse pin portion of the central, the eccentricity of the axial direction perpendicular crude to mold the material for the strike remains the same to be the finish of the material.
　Finish beating step, the first ends of the material for the finishing out, and striking finish in a state where the third coarse pin was horizontal posture to press all the crude pin portion axially perpendicular direction, the pin the final shape of the forged crankshaft including an arrangement angle parts are molded finish that is shaped.
[0028]
　(6) A 3 method of manufacturing a forged crankshaft for cylinder engine, comprising a first preforming step described below, the second preforming step, and the finishing beating process, the series of steps.
　First preforming step, as the crude material to be subjected to molding apparatus of the above (2), of the rough pin portion, the first ends, third coarse pin portion, eccentricity of the axial direction perpendicular There are smaller than √3 / 2 of the eccentricity of the pin portion of the forged crankshaft in directions opposite to each other, the second coarse pin portion of the central, axial and amount of eccentricity perpendicular first, third shaping the crude material that is the same as the eccentricity of the pin portion of the forged crankshaft in a direction perpendicular to the eccentric direction of the rough pin portion.
　Second preforming step, using a molding apparatus of the above (2), as the finishing out for materials, of the crude pin portion, the first ends, third coarse pin portion, an axial direction perpendicular eccentricity amount is in the opposite direction the same as √3 / 2 of the eccentricity of the pin portion of the forged crankshaft to each other, the second coarse pin portion of the central, the eccentricity of the axial direction perpendicular crude to mold the material for the strike remains the same to be the finish of the material.
　Finish beating step, the first ends of the material for the finishing out, and striking finish in a state where the third coarse pin was horizontal position, pressing the first, third coarse pin portion axially perpendicular direction and, the final shape of the forged crankshaft including an arrangement angle of the pin portion is molded finish that is shaped.
The invention's effect
[0029]
　Molding apparatus of the present invention, and according to the manufacturing method including a pre-forming step using the same, from no burrs crude material, the shape of a thin three-cylinder engine forged crankshaft thickness of the arm portion substantially in matching shape , it is possible to mold the material for the hit finish without burrs. If out finishing such finishing out for material no burr, but has some burrs occur, since it is possible to manufacture a final shape of the forged crankshaft including a contour shape of the arm portion, for 3-cylinder engine well forged crankshaft yield, moreover, it is possible to manufacture with high dimensional accuracy regardless of its shape.
BRIEF DESCRIPTION OF THE DRAWINGS
[0030]
[1] Figure 1 is a schematic diagram for explaining a conventional typical three-cylinder engine forged crankshaft manufacturing process.
FIG. 2 is the manufacturing method of the first embodiment of the present invention, the crude material and object to be molded in the molding apparatus, the molded finish out for material and finish of each shape of the finishing material after hitting is a diagram schematically illustrating.
FIG. 3 is a schematic diagram showing a manufacturing process for a three-cylinder engine forged crankshaft in the first embodiment of the present invention.
[4] FIG. 4 is a longitudinal sectional view showing the structure of the molding apparatus in the first embodiment of the present invention.
FIG. 5 is a longitudinal sectional view for explaining a first method of molding the material for out finishing by molding apparatus embodiment of the present invention shown in FIG. 4, showing the molding initial state.
FIG. 6 is a longitudinal sectional view for explaining a first method of molding the material for out finishing by molding apparatus embodiment of the present invention shown in FIG. 4, showing a state during molding completed.
[7] FIG. 7 is a diagram for explaining a situation where out chewy molding material for out finishing occurs by molding apparatus of the present invention.
[8] FIG. 8 is a diagram for explaining a situation when subjected to countermeasures out chewing the molding material for the striking finishing by molding apparatus of the present invention.
[9] FIG. 9 is the manufacturing method of the second embodiment of the present invention, the crude material and object to be molded in the molding apparatus, the molded finish out a material, finishing beating after the finish, and after twisting molding in is a diagram schematically illustrating a shape of the torsion finish.
[10] FIG 10 is a schematic diagram showing a manufacturing process for a three-cylinder engine forged crankshaft in the second embodiment of the present invention.
[11] FIG 11 is a longitudinal sectional view showing the structure of the molding apparatus in the second embodiment of the present invention.
[12] FIG 12 is a longitudinal sectional view for explaining a second method of molding the material for out finishing by molding apparatus embodiment of the present invention shown in FIG. 11, showing a molding initial state.
[13] FIG 13 is a longitudinal sectional view for explaining a second method of molding the material for out finishing by molding apparatus embodiment of the present invention shown in FIG. 11, showing a state during molding completed.
[14] FIG. 14 is the manufacturing method of the third embodiment of the present invention, the crude material and object to be molded in the molding apparatus, the molded finish out for material and finish of each shape of the finishing material after hitting is a diagram schematically illustrating.
[15] FIG 15 is a schematic diagram showing a manufacturing process of the third for 3-cylinder engine forged crankshaft in the embodiment of the present invention.
[16] FIG 16 is a longitudinal sectional view showing the structure of the molding apparatus in a third embodiment of the present invention.
[17] FIG 17 is a longitudinal sectional view for explaining a third method of molding the material for out finishing by molding apparatus embodiment of the present invention shown in FIG. 16, showing a molding initial state.
[18] FIG 18 is a longitudinal sectional view for explaining a third method of molding the material for out finishing by molding apparatus embodiment of the present invention shown in FIG. 16, showing a state during molding completed.
[19] FIG. 19 is the manufacturing method of the fourth embodiment of the present invention, the crude material and object to be molded in the molding apparatus, the molded finish out for material and finish of each shape of the finishing material after hitting is a diagram schematically illustrating.
[20] FIG 20 is a schematic diagram showing a manufacturing process of a fourth for 3-cylinder engine forged crankshaft in the embodiment of the present invention.
DESCRIPTION OF THE INVENTION
[0031]
　In the present invention, upon producing a forged crankshaft for 3-cylinder engine, has assumed to perform the finish beating in the production process, the molding device of the present invention is a finishing beating of the previous step is subjected to the finishing strike used for molding the material for out finishing the crude material. Hereinafter, finishing out material for molding apparatus for forging crankshaft for 3-cylinder engine of the present invention and a 3-cylinder manufacturing method for an engine for a forged crankshaft comprising preforming process using the same, detailed embodiments thereof to.
[0032]
　1. First Embodiment
　1-1. Object to be molded of the crude material, molded finish out for material and finish beating finish after
　Figure 2, in the manufacturing method of the first embodiment of the present invention, the crude material and object to be molded in the molding apparatus, molding It has been finishing out for material, and finishing each shape of finish after hitting a diagram schematically showing. In the drawing, which illustrates the situation in the case of producing the crankshaft of the three-cylinder -4 Like counterweight, in order to facilitate understanding of the shape of each step, and a plan view showing the appearance, along the axial direction They are displayed side by side arrangement view of the pin portion when viewed.
[0033]
　As shown in the figure, crude material 4 of the first embodiment, a coarse crankshaft shape as a whole, while relying on the shape of the forged crankshaft 1 of 3 cylinders -4 Like counterweight shown in FIG. 1 (f) There, four rough journal portion J1a ~ J4A, 3 single coarse pin portions P1a ~ P3a, crude front portion Fra, crude flange FIa, and coarse journal portion J1a ~ J4A and coarse pin portion P1a ~ P3a the six connecting each crude crank arm portion (hereinafter, simply referred to as "coarse arm") consists A1a ~ A6a. The crude material 4 Bali does not have. Hereinafter, crude journal portion J1a ~ J4A crude material 4, crude pin portion P1a ~ P3a, and will be collectively each coarse arm portions A1a ~ A6a, the sign "Ja" in the rough journal portion, in the rough pin " Pa ", referred to as" Aa "in the rough arm portion.
[0034]
　The finishing out for material 5 of the first embodiment, the above crude material 4, detail is intended to be molded by a molding device to be described later, four rough journal portion J1b ​​~ J4B, 3 single coarse pin portions P1b ~ P3b , crude front portion Frb, crude flange FLB, and coarse journal portion J1b ​​~ J4B coarse pin portion P1b ~ 6 sheets of coarse crank arm portion connecting each P3b (hereinafter, simply referred to as "coarse arm") A1b ~ A6b It consists of. It is to hit the material for 5 finish Bali does not have. Hereinafter, will be collectively rough journal portion J1b ​​~ J4B for out finishing material 5, crude pin portion P1b ~ P3b, and each crude arm portion A1b ~ A6b, the sign, "Jb" in rough journal portion, rough pin portion in it referred to as "Pb", "Ab" in the rough arm portion.
[0035]
　Finish 6 in the first embodiment is that obtained by hitting the finishing material 5 for beating finishing above, four journal portions J1c ~ J4c, 3 one pin portion P1c ~ P3c, front portion Frc, flange flc, and journal portion J1c ~ J4c a pin portion P1c ~ 6 sheets of the crank arm portion connecting each P3c (hereinafter, simply referred to as "arm") consists A1c ~ A6c. Hereinafter, the journal portion J1c ~ J4c the finish 6, the pin portion P1c ~ P3c, and will be collectively each arm portion A1c ~ A6c, the sign, in the journal portion "Jc", "Pc" in the pin portion, the arm portion in referred to as "Ac".
[0036]
　The shape of finish 6 is consistent with the shape of the crankshaft including the placement angle of the pin portion Pc (final forged product), equivalent to forging the crank shaft 1 shown in FIG. 1 (f). That is, the journal portion Jc of finish 6, the journal portion J and the axial length of the forged crankshaft final shape is the same. Pin portion Pc of the finish 6, the pin portion length P and the axial direction of the forged crankshaft final shape is the same. Further, the pin portion Pc of the finish 6, compared pin portion P of the forged crankshaft final shape, a eccentricity of the axial direction perpendicular the same, the arrangement angle is also the same 120 °, the normal position It is located in. Arm of the finish 6 Ac is the arm portion A and the axial thickness of the forged crankshaft final shape is the same.
[0037]
　The shape of the finishing out for material 5 is generally matched to the shape of the finish 6, just corresponds to the portion excluding the burr 105a of rough forged material 105 shown in FIG. 1 (d). That is, the coarse journal portion Jb finishing out for material 5, the axial length (journal Jc of finish 6) journal portion J of the forged crankshaft final shape is the same. Crude pin portion Pb of the finishing out for material 5, the axial length (pin portion Pc of the finish 6) the pin portion P of the forged crankshaft final shape is the same. Further, the pin portion Pb of the finishing out material for 5, to the pin portion P of the forged crankshaft final shape, a eccentricity of the axial direction perpendicular the same, the arrangement angle is also the same 120 °, a regular It is arranged at the position. Crude arm Ab finishing out for material 5, the axial thickness (arm Ac of finish 6) arm portion A of the forged crankshaft final shape is the same.
[0038]
　In contrast, crude journal portion Ja of crude material 4 is rough journal portion Jb finishing out for material 5, that is, the axial length (journal Jc of finish 6) journal portion J of the forged crankshaft same it is. Crude pin portion Pa of the crude material 4, coarse pin portion Pb of the finishing out for material 5, that is, the axial length (pin portion Pc of the finish 6) the pin portion P of the forged crankshaft is the same, eccentricity amount is smaller than the coarse pin portion Pb of the strike for the material 5 finish. Specifically, of the crude pin portion Pa of the crude material 4, the first, third coarse pin portion P1a, eccentricity of P3a at both ends, eccentricity of the pin portion P of the forged crankshaft in directions opposite to each other It is the same as the √3 / 2 of. On the other hand, the amount of eccentricity of the second coarse pin portion P2a of central, first, third coarse pin portion P1a, the eccentricity of the pin portion P direction in forging the crank axis orthogonal to the direction of eccentricity of the P3a 1 / there is a 2 about.
[0039]
　Crude arm Aa of the crude material 4, the coarse arm Ab finishing out material for 5, i.e. axial thickness than the (arm Ac of finish 6) arm portion A of the forged crankshaft thick. In short, the coarse material 4, finishing out for material 5 as compared to the (forged crankshaft and finish 6 final shape), and the total length only greater amount the thickness of the coarse arm portion Aa is long, polarization of the crude pin portion Pa core volume is small, and has a relatively gentle crankshaft shape.
[0040]
　However, strictly speaking, the material 5 for beating finish, with respect to the forged crankshaft and finish 6 final shape, the thickness of the coarse arm Ab is slightly thin, that much crude journal portion Jb and coarse pin portion the axial length of the Pb is slightly larger. Material 5 for beating finish during finish stamped easily accommodated in a mold, in order to prevent the occurrence of galling flaws. In response to this, the crude material 4 also, to forged crankshaft and finish 6 final shape, the axial length of the coarse journal portion J 'and coarse pin portion P' is slightly larger.
[0041]
　Manufacturing process for forged crankshaft 1-2.3 cylinder engine
　Figure 3 is a schematic diagram showing a manufacturing process for a three-cylinder engine forged crankshaft in the first embodiment of the present invention. As shown in the figure, the manufacturing method of forging the crank shaft of the first embodiment, the first preformed second preforming, comprises the steps of finishing strike, if necessary, burrs punching, each step of shaping including.
[0042]
　First preforming step is a step of shaping the crude material 4 above. In the first preforming step, that cross section and the raw material round billet round, by performing pre-forming process after heating the round billet by induction heating furnace or gas heating furnace, to shape the crude material 4 it can. For example, the volume of the volume by rolling diaphragm the round billet by grooved rolls do roll forming to allocate longitudinally, thereby resulting roll wasteland partially pressing pressure from the longitudinal and perpendicular directions by performing repeated bending beating to distribute, it is possible to shape the crude material 4. Its Besides, even using the techniques disclosed in Patent Documents 1 and 2, shaping of the crude material 4 is possible. It is also possible to employ a cross roll and closed forging.
[0043]
　Second preforming step is a step of forming the finishing beating material for 5 above. In the second preforming step, by using a molding apparatus shown in Figure 4 below, the above from the crude material 4, the final shape of the forged crankshaft including an arrangement angle of the pin portion is finished beating material for 5, which is shaped it can be molded.
[0044]
　Finish beating step is a step of obtaining a finish 6 above. The finishing beating process, material for out finishing of the 5 is provided, by press forging using a pair of dies vertically, the final shape of the forged crankshaft including an arrangement angle of the pin portion is shaped crank it can be obtained finish 6 shaped to match the axis.
[0045]
　1-3. Molding device of the material for the hit finishing
　Figure 4 is a longitudinal sectional view showing the structure of the molding apparatus in the first embodiment of the present invention. In the figure, 3 forming apparatus in the case of producing the crankshaft of the cylinder -4 sheets counterweight, i.e. illustrates a molding apparatus for molding a material 5 for striking finish from a crude material 4 shown in FIG. 2. Incidentally, in the longitudinal section shown in the figure, first, part of the third coarse pin portion is actually either one but other located in front of the paper is positioned at the back, for convenience, It is shown on the same plane.
[0046]
　As shown in FIG. 4, the molding apparatus is obtained by utilizing a press having a lower hard plates 20 of the underlying fixed, the upper hard plate 21 to descend with the ram of the drive of the press. Directly above the lower hard plates 20 has a lower die support base 22 is elastically supported via the elastic member 24, the lower mold support base 22 is moved is allowed in the vertical direction ing. As the elastic member 24, it is possible to apply such disc springs or coil springs or air springs, it can be applied to hydraulic spring system to other. Directly below the upper hard plate 21 has upper mold support 23 is fixed through the supports 25, the upper mold support 23 is integral with the upper hard plate 21 by the driving of the press (ram) It descends.
[0047]
　In the molding apparatus shown in Figure 4, the crude material 4, the first, third coarse pin unit P1a, a horizontally arranged P3a, in the mold in a position of arranging the second coarse pin portion P2a in a downward vertical direction accommodated, molded for the strike finishing material. Therefore, the lower mold support base 22 and the upper mold support 23 is divided along the axial direction of the crude material 4, a journal type 10U respectively form a vertical against, 10B, and reference pin-type 11 and auxiliary pin mold 13, and the movable pin die 12 and the auxiliary pin mold 13 is attached.
[0048]
　Reference pin mold 11 and the auxiliary pin-type 13 forming a vertically paired, a primary position of one of the rough pin portion Pa of the crude pin portion Pa in the coarse material 4, in FIG. 4, for example, a central second coarse pins is arranged at the position of parts P2a, respectively upper and lower upper mold support 23 is attached to the lower mold support base 22. Reference pin mold 11 of the first embodiment, the side where the normal position of one coarse pin portion Pa as the reference is intended to be arranged on the opposite side, the other auxiliary pin die 13, the crude pin the normal position of the parts Pa are those located outside the side. For example, in the position of the second coarse pin portion P2a, since the arrangement of the second coarse pin portion P2a is the position also lower its normal a lower reference pin type 11 in the upper mold support 23 with attached auxiliary pin mold 13 is attached to the lower mold support base 22 forming a pair therewith.
[0049]
　In particular, the reference pin-type 11 and the auxiliary pin mold 13, both the upper and lower, the upper mold support 23 with respect to the lower die support base 22, movement in the axial direction is restrained. Only the reference pin mold 11 is a perpendicular direction to the axial direction, the movement is allowed in the direction toward the normal position of the rough pin portion Pa (FIG. 4 in a downward direction).
[0050]
　Reference pin die 11, the auxiliary pin die 13, respectively, semi-cylindrical engraved portions 11a, 13a are formed. Engraved portions 11a, the length of 13a is the same as the axial length of the second coarse pin portion P2b in the material 5 for beating finish.
[0051]
　Reference pin mold 11, lowering of the upper mold support 23 with the drive of the press, i.e. the pressure of the press, we engraved portion 11a is destined to a second coarse pin portion P2a, both side surfaces of the reference pin type 11 but the third is the fourth coarse arm portion A3a, into contact with the side surface of the second coarse pin portion P2a side in A4a leading to second coarse pin portion P2a.
[0052]
　Movable pin die 12 and the auxiliary pin-type 13 forming a vertically against the reference pin mold 11 is respectively coarse pin portion Pa of the other coarse pin portion Pa that addressed cracking position, in FIG. 4, for example, first, third coarse pins part P1a, disposed P3a each position, each of the upper and lower upper mold support 23 is attached to the lower mold support base 22. Movable pin die 12 of the first embodiment, the side where the normal position of the rough pin portion Pa is intended to be arranged on the opposite side, the other auxiliary pin die 13, the normal crude pin portion Pa it is intended to be disposed on the outside of the position side. For example, at the position of the first coarse pin portion P1a, since the normal position of the first coarse pin portion P1a is the upper, together with the movable pin die 12 is attached to the lower die support base 22, a pair therewith auxiliary pin mold 13 which forms is attached to the upper mold support 23.
[0053]
　In particular, the movable pin die 12 and the auxiliary pin mold 13, both the upper and lower, the lower mold support base 22, with respect to the upper mold support 23, the movement is allowed in the axial direction toward the reference pin type 11 ing. Only the movable pin die 12, a direction perpendicular to the axial direction, the movement is allowed in the direction toward the normal position of the rough pin portion Pa (FIG. 4 in an upward direction).
[0054]
　Movable pin die 12, the auxiliary pin die 13, respectively, semicylindrical engraved portions 12a, 13a are formed. Engraved portions 12a, the length of 13a is the same as the axial length of each coarse pin portion Pb of the material 5 for beating finish.
[0055]
　Journal type 10 U, 10B is disposed at a position of the coarse journal Ja in the coarse material 4, each of the upper and lower the upper mold support 23 is attached to the lower mold support base 22. In particular, the journal type 10 U, 10B, both the upper and lower, the upper mold support 23 with respect to the lower die support base 22, moved in the axial direction toward the reference pin mold 11 is allowed.
[0056]
　Journal type 10 U, the 10B, respectively, the semi-cylindrical first engraved portion 10Ua, 10Ba and, the first engraved portion 10Ua, the second engraved portions adjacent the front and rear (in FIG. 4, left and right) of 10Ba 10UB, 10Bb There has been formed. First engraved portion 10Ua, the length of the 10Ba is the same as the axial length of the coarse journals Jb in material 5 for beating finish. Second engraved portion 10UB, the length of 10Bb is the same as the axial thickness of the coarse arm Ab leading to the crude journal portion Jb in material 5 for beating finish.
[0057]
　Journal type 10 U, 10B is lowered the upper mold support 23 with the drive of the press, i.e. the pressure of the press, the first engraved portion 10Ua, sandwiched from above and below each crude journal portion Ja individually 10Ba holding to. At the same time, journal type 10 U, 10B, the second engraved portion 10UB, first engraved part 10Ua of 10Bb, the surface of the 10Ba side, of each coarse journals Ja side in the coarse arm Aa connected to each coarse journals Ja It is in contact to the side surface.
[0058]
　At that time, the reference pin die 11, the movable pin die 12, lowering of the upper mold support 23 with the drive of the press, i.e. the pressure of the press, engraved portion 11a, is addressed 12a within each coarse pin portion Pa We, the reference pin-type 11, both side surfaces of the movable pin die 12 is in contact to the side of each coarse pin portion Pa side in the coarse arm Aa connected to each coarse pin portion Pa.
[0059]
　Here, first, the end face of the fourth rough journal portion J1a, journal type disposed at the position of J4A 10 U, 10B at both ends, the inclined surface 14U, and has a 14B. In contrast, on the lower hard plates 20, first of them, the fourth coarse journal portion J1a, journaled 10U of J4A, 10B of the inclined surface 14U, corresponding to the position of 14B, individually, first wedge 26 is erected, the first wedge 26 protrudes upwardly through the lower mold support base 22. First, fourth coarse journal portion J1a, journaled 10U of J4A, among 10B, the inclined surface 14B of the lower journal die 10B is in contact with the inclined surface of the first wedge 26 in the initial state. On the other hand, the inclined surface 14U of the upper journal type 10U is the lowering of the upper mold support 23 with the drive of the press, i.e. the pressure of the press is in a state of being in contact with the inclined surface of the first wedge 26.
[0060]
　The second inboard, third coarse journal portion J2a, journal type disposed at the position of J3A 10 U, the 10B, first engraved portion 10Ua, 10Ba and the second engraved portion 10UB, sides deviated from 10Bb (the front and back of the paper in FIG. 4), the inclined surface 15U, is block (not shown) having 15B are fixed. In contrast, on the lower hard plates 20, the second of them, third coarse journal portion J2a, journaled 10U of J3A, 10B of the inclined surface 15U, corresponding to the position of 15B, individually, the second wedge 27 are erected, each of the second wedge 27, and protrudes upwardly through the lower mold support base 22. The second, third coarse journal portion J2a, journaled 10U of J3A, among 10B, the inclined surface 15B of the lower journal die 10B is in contact with the initial state on the slope of the second wedge 27. On the other hand, the inclined surface 15U of the upper journal type 10U is the lowering of the upper mold support 23 with the drive of the press, i.e. the pressure of the press is in a state of being in contact with the inclined surface of the second wedge 27.
[0061]
　Then, along with the continuation of the pressure of the press, the upper journal type 10U is depressed in the journal-type 10B integral with the lower side. Thus, since the first, fourth coarse journal portion J1a, movable journaled 10U of J4A, 10B, both the upper and lower, that the inclined surfaces 14U, 14B slides along the inclined surface of the first wedge 26, so moves axially toward the reference pin mold 11 of the second coarse pin portion P2a as a reference. At the same time, since the second, third coarse journal portion J2a, journal type J3A 10 U, 10B, both the upper and lower, that the inclined surfaces 15U, 15B slides along the inclined surface of the second wedge 27, so moves axially toward the reference pin mold 11 of the second coarse pin portion P2a as a reference. In short, the journal type 10 U, 10B can be moved axially by the individual wedge mechanism.
[0062]
　Further, the movable pin die 12 and the auxiliary pin mold 13 is pushed down integrally with the continuation of the pressure of the press. Thus, the movable pin die 12 and the auxiliary pin mold 13 is brought to the journal type 10U as described above, 10B are moved in the axial direction, toward the reference pin mold 11 of the second coarse pin portion P2a as a reference moves in the axial direction Te. Also, movement in the axial direction perpendicular to the direction of the reference pin die 11 and the movable pin die 12 is performed by driving the hydraulic cylinder 16 connected to the pin-type 11 and 12.
[0063]
　The movement of the movable pin die 12 in the axial direction of the auxiliary pin die 13, a journal type 10 U, same wedge mechanism and the 10B, and a hydraulic cylinder, with a separate mechanism such as a servo motor, carried out compulsorily it may be. Auxiliary pin die 13, may be integrated with one of adjacent pair of journal type 10 U, 10B.
[0064]
　In the initial state shown in FIG. 4, a journal type 10 U, 10B, and to allow axial movement of the movable pin die 12 and the auxiliary pin die 13, and the journal type 10 U, 10B contiguous individually axially, the reference pin-type 11, between the movable pin die 12 and the auxiliary pin-type 13, a gap is ensured. The dimensions of each of these gaps is the difference between the thickness of the coarse arm Aa in the thickness of the coarse arm Ab in material 5 for beating finishing crude material 4.
[0065]
　Next, a description will be given such a configuration method of molding the material for out finishing by molding apparatus.
　5 and 6 are longitudinal sectional views for explaining a first method of molding the material for out finishing by molding apparatus embodiment of the present invention shown in FIG. 4, FIG. 5 shows a state of forming the initial, Figure 6 shows a state during molding completed, respectively.
[0066]
　Journal die 10B of the lower side shown in FIG. 4, the crude material 4 is accommodated in the movable pin die 12 and the auxiliary pin die 13, to start the reduction of the pressing machine. Then, first, as shown in FIG. 5, the upper journal type 10U, respectively, abut against the lower side of the journal type 10B.
[0067]
　Thus, the coarse material 4, each coarse journal portion Ja is held from the upper and lower journal type 10 U, by 10B, reference pin die 11 and the movable pin die 12 to each coarse pin portion Pa is in a state where destined Broken. In this state, the side surface of the rough journal portion Ja side of each coarse arm portions Aa of crude material 4, a journal type 10 U, 10B contacts the side surface of the rough pin portion Pa side of each coarse arm portion Aa is reference pin die 11 and the movable pin die 12 are in contact. Further, in this state, first, fourth coarse journal portion J1a, journaled 10U of J4A, 10B of the inclined surfaces 14U, 14B comes into contact with the inclined surface of the first wedge 26, a second, third coarse journal portion J2a , journaled 10U of J3A, 10B of the inclined surfaces 15U, 15B are in contact with the inclined surface of the second wedge 27.
[0068]
　From this state, to continue the pressure of the press as it is. Then, the first, fourth coarse journal portion J1a, journal type J4A 10 U, 10B, each of the inclined surfaces 14U, 14B slides along the inclined surface of the first wedge 26, this wedge mechanism, a second crude moves in the axial direction toward the reference pin type 11 of the pin portion P2a. At the same time, second, third coarse journal portion J2a, journal type J3A 10 U, 10B, each of the inclined surfaces 15U, 15B slides along the inclined surface of the second wedge 27, this wedge mechanism, the moves in the axial direction toward the reference pin type 11 2 coarse pin portion P2a. Thus journaled 10 U, 10B along with the movement by the wedge mechanism axially individually movable pin die 12 and the auxiliary pin die 13 is also moved in the axial direction toward the reference pin type 11.
[0069]
　Thus, a journal type 10 U, 10B, the reference pin-type 11, narrowing gradually the gap between the movable pin die 12 and the auxiliary pin-type 13, each of which gaps is eliminated in the final. At that time, crude material 4 is journaled 10 U, 10B, the reference pin-type 11 and the movable pin die 12, while the axial length of the coarse journal portion Ja and coarse pin portion Pa is maintained, the coarse arm Aa is clamped in the axial direction, the thickness of the coarse arm Aa is reduced to a thickness of the coarse arm Ab threshing material for 5 finish (see FIG. 6).
[0070]
　Also, the journal type 10 U, 10B, and depending on the axial movement of the movable pin die 12 and the auxiliary pin die 13, to drive the reference pin die 11 and the movable pin die 12 each hydraulic cylinder 16. Then, each pin-type 11 and 12, individually, to press the rough pin portion Pa of the crude material 4 in the axial direction and perpendicular. Thus, the coarse pin portion Pa of the crude material 4, since the axially offset and perpendicular vertical, is increased to the eccentricity amount of coarse pin portion Pb of the strike for the material 5 that eccentricity is finishing, either crude pin portion Pb is also a state of being arranged in the normal position (see FIGS. 2 and 6).
[0071]
　In this way, from the crude material 4 without burrs, the arm portion is thin three-cylinder engine forged crankshaft A shape roughly matching the shape of the (final forged product), the material 5 for beating finish without burrs it can be molded. Then, by performing such was subjected to finish out a material 5 without burrs finish beating by finishing beating, although some burrs occur, three-cylinder engine including an arrangement angle of the contour shape and the pin portion of the arm portion the final shape of use forged crankshaft can be shaped. Therefore, good yield forged crankshaft for 3-cylinder engine, moreover, it is possible to manufacture with high dimensional accuracy regardless of its shape. However, if by shaping the portion corresponding to the balance weight on the arm portion in the crude material stage, it is also possible the production of forged crankshaft with balance weight.
[0072]
　FIG 4, in the molding apparatus shown in FIGS. 5 and 6, the journal type 10U of the first coarse journal portion J1a, 10B of the inclined surface 14U, and the slope of the first wedge 26 to 14B and in contact with this, the fourth coarse journal journaled 10U parts J4A, 10B of the inclined surface 14U, and the 14B and which the slope of the first wedge 26 in contact, the inclination angle is the opposite relative to the vertical plane. Also, the journal type 10U of the second coarse journal portion J2a, 10B of the inclined surfaces 15U, 15B and the inclined surface of the second wedge 27 in contact therewith, journaled 10U of the third coarse journal J3A, 10B of the inclined surface 15U, the 15B and slopes of the second wedge 27 in contact with this, the inclination angle is the opposite relative to the vertical plane. Furthermore, the slope angle of the first wedge 26 (the first, fourth coarse journal portion J1a, journaled 10U of J4A, 10B of the inclined surface 14U, the angle of 14B), the angle of the inclined surface of the second wedge 27 (second , third coarse journal portion J2a, journaled 10U of J3A, 10B of the inclined surface 15U, which is larger than the angle) of 15B. The reason that with different wedge angles of the journal type 10 U, wedge mechanism for moving the 10B axially journaled 10 U, per. 10B, reduces the thickness of the crude arm portion Aa and nipped in the axial direction This is to a deformation speed to be constant at all coarse arm portion Aa.
[0073]
　FIG 4, crude material 4 used in the molding apparatus shown in FIGS. 5 and 6, the cross-sectional area of ​​the coarse journal portion Ja is finishing out for material 5 of the coarse journal portion Jb, i.e. interruption of the journal portion J of the forged crankshaft or is the same as the area is larger than that. Similarly, the cross-sectional area of ​​the coarse pin portion Pa of the crude material 4, coarse pin portion Pb of the finishing out material for 5, i.e. whether it is the same as the cross-sectional area of ​​the pin portion P of the forged crankshaft, larger than that. Greater than the cross-sectional area of ​​the coarse journal portion Jb threshing material for 5 finish the cross-sectional area of ​​the coarse journal portion Ja of crude material 4, the coarse pin portion of the strike for the material 5 is finish the cross-sectional area of ​​the coarse pin portion Pa of the crude material 4 even when greater than the cross sectional area of ​​the pb, journaled 10U, 10B of the crude journal portion Ja pinching hold, and journal type 10U following it, along with the axial movement of the 10B, the coarse journal portion Ja until the cross-sectional area of ​​the coarse journal portion Jb threshing material for 5 finish the cross-sectional area can be reduced, in addition to the movement in the axial direction perpendicular to the direction of the reference pin type 11, axial movement of the movable pin type 12 and with the movement to this perpendicular direction, it can be reduced to the cross-sectional area of ​​the coarse pin portion Pb of the strike for the material 5 finish the cross-sectional area of ​​the coarse pin portion Pa.
[0074]
　It should be noted molding materials for striking finish described above, there is occurrence of localized chewing out. The following is a description generation principle of out chewing and their countermeasures.
[0075]
　Figure 7 is a diagram for explaining a situation where the chewing out by molding occurs the material for out finishing by molding apparatus of the present invention, FIG. 8, for explaining the situation when subjected to the countermeasure it is a diagram. In FIG. 7 and FIG. 8, (a) shows the state of forming the initial, the (b) is in the middle of molding conditions, (c) a state during molding completed, (d) was taken out from the molding apparatus after completion molding shows the material for the hit finish, respectively.
[0076]
　As shown in FIG. 7 (a), when the molding is started, with the journal type 10 U, 10B are moved in the axial direction, the movable pin die 12 and the auxiliary pin die 13 is moved in the axial direction and which perpendicular . Thereafter, as shown in FIG. 7 (b), the journal type 10 U, 10B, and before the movement in the axial direction of the movable pin die 12 and the auxiliary pin die 13 is completed, i.e., journal type 10 U, 10B and the reference pin-type 11, before the gap between the movable pin die 12 and the auxiliary pin die 13 is closed, the coarse pin portion Pa for pressing deformed axially perpendicular direction reaches the auxiliary pin-type 13, the auxiliary pin type 13 a journal type 10 U, the gap between 10B, meat coarse pin portion Pa ends up flowing. The inflow meat, although gradually extended thinly with the progress of molding, as shown in FIG. 7 (c), also remain in the molding complete. Thus, as shown in FIG. 7 (d), on the outside of the coarse pin portion Pb of the finishing out for material 5, the boundary between the adjacent coarse arm Aa local chewing out section 5a appears.
[0077]
　Chewing out section 5a is a head flaws driven into the product on a finish beating the next step. Therefore, in order to ensure the product quality, it is necessary to prevent the occurrence of out chewing.
[0078]
　The countermeasures to prevent the occurrence of out chewing, journal type 10 U, and 10B, the reference pin-type 11, after the gap between the movable pin die 12 and the auxiliary pin die 13 is closed, the coarse pin portion Pa for pressing deformation so as to reach the auxiliary pin mold 13 may be controlled to move in the axial direction perpendicular to the direction of the reference pin die 11 and the movable pin die 12. Specifically, the journal type 10 U, 10B, and after the axial movement of the auxiliary pin-type 13 which forms a movable pin die 12 and the movable pin die 12 and the counter has been completed, the reference pin-type 11 and the movable pin die 12 movement in the axial direction perpendicular to the direction of it is sufficient to complete the. For example the movement of, when the reference pin-type 11 and the total distance traveled in the axial direction perpendicular to the direction of movable pin die 12 to 100%, journaled 10U adjacent to the pin-type 11 and 12, in the axial direction of the 10B There upon completion, the moving distance in the axial direction perpendicular to the direction of the pin-type 11, 12 to 90% of the total distance traveled (more preferably below 83% is more preferred below 60%), and it is preferable to thereafter move in that direction of the pin-type 11, 12 is completed.
[0079]
　That is, as shown in FIG. 8 (a), to start the forming, then, as shown in FIG. 8 (b), the moving distance in the axial direction perpendicular to the direction of the reference pin die 11 and the movable pin die 12 is to reach 90% of the total distance traveled, the journal type 10 U, 10B, and to complete the movement in the axial direction of the movable pin die 12 and the auxiliary pin-type 13. Then, at this time, the journal type 10 U, and 10B, the reference pin-type 11, although the gap between the movable pin die 12 and the auxiliary pin mold 13 is closed, the coarse pin portion Pa auxiliary pin type 13 for pressing deformation It has not been reached. When the rough pin portion Pa with the movement in the axial direction perpendicular to the direction of the pin-type 11 and 12 reaches the auxiliary pin-type 13, the movement is completed, as shown in FIG. 8 (c), the molding There is completed. Therefore, the auxiliary pin-type 13 and journal-type 10 U, the gap between 10B, situation in which the meat of the coarse pin portion Pa flows does not occur. Thus, as shown in FIG. 8 (d), it is possible to obtain a material 5 for beating finishing without chewing out high quality.
[0080]
　Transfer process to the pin-type axially perpendicular direction to the movement in the axial direction of the journal-type is completed, can be arbitrarily changed. For example, the movement of the pin-type axially perpendicular direction may be started simultaneously with the start of movement in the axial direction of the journal type, it than may be started before or journaled shaft movement in the direction may be started from in progress to some extent. Also, the movement of the pin-type axially perpendicular direction, after the start, temporarily stopped at a position a certain amount of movement, may be resumed after the movement in the axial direction of the journal-type is completed.
[0081]
　2. Second Embodiment
　The second embodiment, which is basically the structure of the first embodiment described above, with the addition of torsional molding step to the production process of forged crankshaft for 3-cylinder engine, obtained by modifying the configuration related to this it is.
[0082]
　2-1. Object to be molded of the crude material, molded finish out a material, finish after finish beating, and twisting finish after twisting molding
　9 is the manufacturing method of the second embodiment of the present invention, the at molding device crude material to be press-formed, molded finish out a material, finish after finish beating, and is a diagram schematically illustrating a shape of the torsion finish after twisting molding. In the drawing, which illustrates the situation in the case of producing the crankshaft of 3 cylinders -6 Like counterweight, as in FIG. 2, a plan view showing an external appearance, a pin when viewed along the axial direction They are displayed side by side layout of parts. Incidentally, omitted in order to avoid redundancy and the first embodiment as appropriate. Third, which will be described later, and also in the fourth embodiment.
[0083]
　As shown in FIG. 9, the crude material 4 of the second embodiment is a rough crankshaft shape as a whole, while relying on the shape of the forged crankshaft 1 of 3 cylinders -6 Like counterweight, four rough journal portion Ja, 3 single coarse pin portions Pa, crude front portion Fra, crude flange FIa, and consists of six crude arm portion Aa. The finishing out for material 5 of the second embodiment, the above crude material 4, which details are molded by a molding device to be described later, four crude journals Jb, 3 single coarse pin portions Pb, crude front portion frb, crude flange FLB, and consists of six crude arm Ab. Finish 6 of the second embodiment is one obtained by beating finishing materials 5 for beating finishing the above four journals Jc, 3 one pin portion Pc, a front portion Frc, flange Flc and 6, sheets consisting of the arm portion Ac.
[0084]
　Twisting finish 7 of the second embodiment is that obtained by the above the finish 6 and torsion molding, four journal portions J1d ~ J4d, 3 one pin portions P1d ~ P3d, the front portion Frd, flange Fld , and journal portion J1d ~ J4d a pin portion P1d ~ 6 sheets of the crank arm portion connecting each P3d (hereinafter, simply referred to as "arm") composed of A1d ~ A6d. Hereinafter, the torsional finish 7 of the journal portion J1d ~ J4d, pin P1d ~ P3d, and will be collectively each arm portion A1d ~ A6d, the sign, in the journal portion "Jd", "Pd" in the pin, the arm It referred to as "Ad" in parts.
[0085]
　The shape of the torsion finish 7 is consistent with the shape of the crankshaft (final forged product), including the placement angle of the pin portion Pd. That is, the journal portion Jd torsion finish 7, the journal portion J and the axial length of the forged crankshaft final shape is the same. Pin portion Pd of the torsion finish 7, pin length P and the axial direction of the forged crankshaft final shape is the same. Further, the pin portion Pd of the torsion finish 7, compared pin portion P of the forged crankshaft final shape, a eccentricity of the axial direction perpendicular the same, the arrangement angle is also the same 120 °, a regular It is disposed at a position. Arm Ad torsion finish 7, the arm portion A and the axial thickness of the forged crankshaft final shape is the same.
[0086]
　The shape of finish 6 is consistent with the shape of the crankshaft (final forged product) except placement angle of the pin portion Pc. That is, the journal portion Jc of finish 6, the journal portion J and the axial length of the forged crankshaft final shape is the same. Pin portion Pc of the finish 6, the pin portion length P and the axial direction of the forged crankshaft final shape are the same, eccentricity of the axial perpendicular direction is the same. However, the arrangement angle of the pin portion Pc of the finish 6 is out of the normal position. Specifically, of the pin portion Pc of the finish 6, the first ends, the third pin portion P1c, P3c is eccentric in the same direction in the axial direction and perpendicular direction center of the second pin portion P2c is eccentric in a direction opposite to the first, third pin portion P1c, eccentric direction P3c. Arm of the finish 6 Ac is the arm portion A and the axial thickness of the forged crankshaft final shape is the same.
[0087]
　The shape of the finishing out for material 5 is generally consistent with the shape of the finish 6. That is, the coarse journal portion Jb finishing out for material 5, the axial length (journal Jc of finish 6) journal portion J of the forged crankshaft final shape is the same. Crude pin portion Pb of the finishing out material for 5, to the pin portion P of the forged crankshaft final shape (pin portion Pc of the finish 6), a length in the axial direction is the same, the axial direction perpendicular of but eccentricity is the same, is out of Likewise the normal position and its placement angle finish 6. Crude arm Ab finishing out for material 5, the axial thickness (arm Ac of finish 6) arm portion A of the forged crankshaft final shape is the same.
[0088]
　In contrast, crude journal portion Ja of crude material 4 is rough journal portion Jb finishing out for material 5, that is, the axial length (journal Jc of finish 6) journal portion J of the forged crankshaft same it is. Crude pin portion Pa of the crude material 4, coarse pin portion Pb of the finishing out for material 5, that is, the axial length (pin portion Pc of the finish 6) the pin portion P of the forged crankshaft is the same, eccentricity amount is smaller than the coarse pin portion Pb of the strike for the material 5 finish. Specifically, of the crude pin portion Pa of the crude material 4, the first ends, third coarse pin portion P1a, eccentricity of P3a is the eccentricity of the pin portion P of the forged crankshaft in the same direction which is about 1/2. On the other hand, the amount of eccentricity of the center of the second coarse pin portion P2a is first, third coarse pin portion P1a, eccentricity of the pin portion P of the forged crankshaft in a direction opposite to the direction of eccentricity of the P3a 1/2 there is a degree. Crude arm Aa of the crude material 4, the coarse arm Ab finishing out material for 5, i.e. axial thickness than the (arm Ac of finish 6) arm portion A of the forged crankshaft thick.
[0089]
　2-2.3 cylinder manufacturing process of the engine forged crankshaft
　10 are schematic views showing a manufacturing process for a three-cylinder engine forged crankshaft in the second embodiment of the present invention. As shown in the figure, the manufacturing method of forging the crank shaft of the second embodiment, the first preformed second preformed, finish out, it comprises the steps of twisting molding, optionally, prior to twisting shaping Bali opener, comprising the steps of shaping after twisting molding.
[0090]
　First preforming step is a step of shaping the crude material 4 above. Second preforming step, by using a molding apparatus shown in Figure 11 below, the above from the crude material 4, except for the arrangement angle of the pin portion forged crankshaft final shape is material for finishing beating defined above which is shaped 5 is a step of forming a. Finish beating process, material 5 for beating finishing the above is provided, the final shape of the forged crankshaft except placement angle of the pin portion is a step of obtaining a finish 6 above that have been shaped.
[0091]
　Twisting forming step is a step of obtaining the above-mentioned torsion finish 7. The twisting molding process, by twisting around the axis in the journal portion while holding the journal portion and the pin portion of the finishing material 6, the arrangement angle of the pin portion on the arrangement angle of the pin portion of the forged crankshaft adjusting the final shape of the forged crankshaft including an arrangement angle of the pin portion is shaped, it is possible to obtain a torsional finish 7 shaped to conform to the crankshaft.
[0092]
　2-3. Molding device of the material for the strike finishing
　Figure 11 is a longitudinal sectional view showing the structure of the molding apparatus in the second embodiment of the present invention. In the figure, 3 forming apparatus in the case of producing the crankshaft of the cylinder -6 sheets counterweight, i.e. illustrates a molding apparatus for molding a material 5 for striking finish from a crude material 4 shown in FIG. 9. The longitudinal section shown in the figure, are included on the same plane actually part of all crude pin portion.
[0093]
　In the molding apparatus of the second embodiment shown in FIG. 11, the crude material 4, the direction of eccentricity of the crude pin portion Pa fit in the vertical direction, for example, placed first, third coarse pin portions P1a and P3a on the second crude pin portion P2a accommodated in the mold in a posture that is disposed below, formed into a striking finishing material 5. Configuration other than this point, because in common with the molding device of the first embodiment shown in FIG. 4, a detailed description thereof will be omitted.
[0094]
　12 and 13 are longitudinal sectional views for explaining a second method of molding the material for out finishing by molding apparatus embodiment of the present invention shown in FIG. 11, FIG. 12 is a molded initial state, FIG. 13 shows a state during molding completed, respectively.
[0095]
　As shown in the figure, the lower side of the journal type 10B, houses the crude material 4 in the movable pin die 12 and the auxiliary pin die 13, when the pressure of the press, a journal type 10U holding the respective crude journal portion Ja , 10B is, toward the reference pin type 11 destined is cracking the second coarse pin portion P2a moves in the axial direction, along with this, the first, third coarse pin portion P1a, movable with cracks is addressed to the P3a pin-type 12 and the auxiliary pin die 13 is also moved in the axial direction toward the reference pin type 11. Thus, the coarse material 4 is journaled 10 U, 10B, and the reference pin mold 11 and the movable pin die 12, while the axial length of the coarse journal portion Ja and coarse pin portion Pa is maintained, the coarse arm Aa There is clamped in the axial direction, the thickness of the coarse arm Aa is reduced to a thickness of the coarse arm Ab threshing material for 5 finish (see FIG. 13).
[0096]
　Also, the journal type 10 U, 10B, and depending on the axial movement of the movable pin die 12 and the auxiliary pin die 13, the reference pin-type 11 and the movable pin die 12, with the drive of the respective hydraulic cylinders 16, individually presses the rough pin portion Pa of the crude material 4 in the axial direction and perpendicular. Thus, the coarse pin portion Pa of the crude material 4, since the axially offset and perpendicular, while the arrangement angle is not deviated from the regular position, the coarse pin portion of the strike for the material 5 that eccentricity is finish the state of being increased to eccentricity of pb (see FIG. 9, FIG. 13).
[0097]
　In this way, the burr-free crude material 4, with the exception of the placement angle of the pin portion P, a shape of the arm portion is thin three-cylinder engine forged crankshaft A (final forged product) generally in matching shape , it is possible to mold the material 5 for beating finish without burrs. Then, by performing such a burr finishing out material for 5 to finish beating subjected to the finish beating without, although some burrs occur, except for the arrangement angle of the pin portion, including the contour of the arm 3 it is possible to manufacture a finish 6 final shape forging crankshaft for cylinder engine. Then, if Hodokose molding twisting to the finish 6, it is possible to manufacture a final shape of the forged crankshaft for 3-cylinder engine, including an arrangement angle of the pin portion. Therefore, good yield forged crankshaft for 3-cylinder engine, moreover, it is possible to manufacture with high dimensional accuracy regardless of its shape.
[0098]
　3. Third Embodiment
　The third embodiment is first described, the configuration of the second embodiment is basically without adding torsional molding step to the production process of forged crankshaft for 3-cylinder engine, the crank in finishing beating step in order to intentionally shaping the final shape of the shaft, it is a modification of the structure related thereto.
[0099]
　3-1. Object to be molded of the crude material, molded finish out material for, and the finishing finish after beating
　Figure 14 is the manufacturing method of the third embodiment of the present invention, the crude material and object to be molded in the molding apparatus, molding It has been finishing out for material, and finishing each shape of finish after hitting a diagram schematically showing. In the drawing, it illustrates the situation in the case of producing the crankshaft of the three-cylinder -4 Like counterweight.
[0100]
　As shown in FIG. 14, the coarse material 4 of the third embodiment, a coarse crankshaft shape as a whole, while relying on the shape of the forged crankshaft 1 of 3 cylinders -4 Like counterweight, four rough journal portion Ja, 3 single coarse pin portions Pa, crude front portion Fra, crude flange FIa, and consists of six crude arm portion Aa. The finishing out for material 5 of the third embodiment, the above crude material 4, which details are molded by a molding device to be described later, four crude journals Jb, 3 single coarse pin portions Pb, crude front portion frb, crude flange FLB, and consists of six crude arm Ab. Finish 6 of the third embodiment is one obtained by beating finishing materials 5 for beating finishing the above four journals Jc, 3 one pin portion Pc, a front portion Frc, flange Flc and 6, sheets consisting of the arm portion Ac.
[0101]
　The shape of finish 6 is consistent with the shape of the crankshaft (final forged product), including the placement angle of the pin portion Pc. That is, the journal portion Jc of finish 6, the journal portion J and the axial length of the forged crankshaft final shape is the same. Pin portion Pc of the finish 6, the pin portion length P and the axial direction of the forged crankshaft final shape is the same. Further, the pin portion Pc of the finish 6, compared pin portion P of the forged crankshaft final shape, a eccentricity of the axial direction perpendicular the same, the arrangement angle is also the same 120 °, the normal position It is located in. Arm of the finish 6 Ac is the arm portion A and the axial thickness of the forged crankshaft final shape is the same.
[0102]
　In contrast, crude journal portion Jb finishing out for material 5, the journal portion Jc of finish 6, that is, the journal portion J and the axial length of the forged crankshaft is the same. Crude pin portion Pb of the finishing out for material 5, the pin portion Pc of the finish 6, i.e. the pin portion length P and the axial direction of the forged crankshaft have the same eccentricity amount arrangement angles the normal position It is out from. Specifically, of the crude pin portion Pb of the finishing out for material 5, the first ends, third coarse pin portion P1b, eccentricity of P3b are polarization of the pin portion P of the forged crankshaft in directions opposite to each other It is the same as √3 / 2 of the core weight. On the other hand, the second coarse pin portion P2b of the central without being eccentric, eccentricity is zero. Crude arm Ab finishing out for material 5, the axial thickness (arm Ac of finish 6) arm portion A of the forged crankshaft final shape is the same.
[0103]
　Further, crude journal Ja of crude material 4 is a rough journal portion Jb finishing out for material 5, that is, the axial length (journal Jc of finish 6) journal portion J of the forged crankshaft same . Crude pin portion Pa of the crude material 4, coarse pin portion Pb of the finishing out for material 5, that is, the axial length (pin portion Pc of the finish 6) the pin portion P of the forged crankshaft is the same. However, among the rough pin portion Pa of the crude material 4, the first, third coarse pin portion P1a, eccentricity of P3a is smaller than that of the finishing out for material 5, in the opposite direction of the forged crankshaft to each other is smaller than √3 / 2 of the eccentricity of the pin portion P. On the other hand, the amount of eccentricity of the second coarse pin portion P2a is similar to the finishing out for material 5, are zero. Crude arm Aa of the crude material 4, the coarse arm Ab finishing out material for 5, i.e. axial thickness than the (arm Ac of finish 6) arm portion A of the forged crankshaft thick.
[0104]
　3-2.3 cylinder manufacturing process of the engine forged crankshaft
　15 is a schematic view showing a third manufacturing process for a three-cylinder engine forged crankshaft in the embodiment of the present invention. As shown in the figure, the manufacturing method of forging the crank axis of the third embodiment, the first preformed second preforming, comprises the steps of finishing strike, if necessary, burrs punching, each step of shaping including.
[0105]
　First preforming step is a step of shaping the crude material 4 above. Second preforming step, by using a molding apparatus shown in Figure 16 below, the above crude material 4, the final shape of the forged crankshaft except eccentricity and arrangement angles of all of the pin portion is shaped a step of molding the finish beating material for 5 above.
[0106]
　Finish beating step is a step of obtaining a finish 6 above. The finishing beating step is subjected is material 5 for beating finishing above, the first, in the state of the third posture placing the crude pin horizontally, by pressing forging using a pair of dies vertically, pressing all the crude pin portion axially perpendicular vertical. Accordingly, the final shape of the forged crankshaft including an arrangement angle of the pin portion is shaped, it is possible to obtain a finish 6 shaped to conform to the crankshaft.

claims

In the process of producing the forged crankshaft for 3-cylinder engine, an apparatus for molding a material for out finishing subjected to finishing strike to shape the final shape of the forged crankshaft
　journal portion and the axial length of the forged crankshaft the same roughness journal portion of the pin portion and the axial length is the same coarse pin portion of the forged crankshaft, and a thick crude crank arm portion axial thickness than the crank arm portion of the forged crankshaft is shaped respectively from a crude material, an apparatus for molding a material for out finishing,
　coarse pin portion of the crude material is smaller than the eccentricity of the eccentric amount of the axial direction perpendicular pin portion of the forged crankshaft ,
　the molding apparatus,
　is disposed at a position of one coarse pin portions of the rough pin, with addressed cracking in the coarse pin, while in contact with the side surface of the rough crank arm portion leading to the rough pin portion, axial direction The movement of the restraint, the reference pin-type which moves in the axial direction and perpendicular,
　reference pin type arranged coarse pin portion of each position other than crude pin portion destined cracking, is addressed to the respective the roughness pin portion with cracking, each being in contact with the side surface of the rough crank arm portion leading to the rough pin portion, and a movable pin type which moves in the axial direction and the axial direction perpendicular to a direction toward the reference pin-type,
　rough journal portions of each is disposed at a position holds sandwiched individually the crude journal portion in the axial direction and perpendicular, while each in contact with the side surface of the rough crank arm portion leading to the rough journal portion, toward the reference pin-type comprising a journal type that moves in the axial direction, and
　The crude journal portion held sandwiched in the journal-type, the reference pin-type and movable pin type from destined wants state to the rough pin moves the journal-type axially moving the movable pin type axially At the same time is moved in the axial direction perpendicular direction while, by moving the reference pin-type axially perpendicular direction, the crude crank arm portion nipped axially crank arm portion of the thickness forged crankshaft a slight proportion to the thickness, the crude pin portion is pressed axially perpendicular direction to increase its eccentricity amount to eccentricity of the pin portion of the forged crankshaft, beating finish forging crankshaft for 3-cylinder engine molding apparatus of use materials.
[Requested item 2]
　In the molding apparatus according to claim 1,
　wherein the reference pin-type and the movable pin type, is arranged outside the opposite to the reference pin-type and said side movable pin type is We have addressed in each of the coarse pin portion and it includes an auxiliary pin-type,
　the journal-type, and the moves to an auxiliary pin-type axial direction forming the movable pin type and the movable pin type paired with the journal-type, the reference pin-type , after the gap between the movable pin type and the auxiliary pin type it is closed, so that the rough pin portion for pressing deformation reaches the auxiliary pin-type, the axial direction of the reference pin-type and the movable pin type to move in the direction perpendicular controlled, material forming apparatus for beating finish forging crankshaft for 3-cylinder engine.
[Requested item 3]
　In the molding apparatus according to claim 2,
　it is taken as 100% of the total movement distance to the reference pin-type and axial perpendicular direction of the movable pin type, the axial direction of the journal-type adjacent to the pin-type when the movement is completed to the movement distance in the axial direction perpendicular to the direction of the pin type is not more than 90% of the total distance, the movement in the axial direction perpendicular to the direction of the pin type after this complete, the material forming apparatus for beating finish forging crankshaft for 3-cylinder engine.
[Requested item 4]
　In the molding apparatus according to any one of claims 1 to 3,
　the reference pin-type, the movable pin type and the journal type is attached to the pressing in a direction along the axial direction and perpendicular capable press and,
　with the pressure of the press, along with the journal type holds sandwich the crude journal portion, addressed to cracking on the reference pin-type and the movable pin type the rough pin portion, reduction of intact press with to continue, at the same time when the journal type is moved in the axial direction by individually wedge mechanism, along with the movement of the journal type, the movable pin type individually moving in the axial direction, for 3-cylinder engine molding device of the material for out finish forged crankshaft.
[Requested item 5]
　In the molding apparatus according to claim 4,
　the wedge angle of the wedge mechanism are different from each other in each of the journal-type, the molding device of the material for out finish forging crankshaft for 3-cylinder engine.
[Requested item 6]
　In the molding apparatus according to claim 4 or 5,
　wherein the reference pin-type and the movable pin type is connected to the hydraulic cylinder, is moved by driving the hydraulic cylinder in the axial direction and a direction perpendicular, for 3-cylinder engine molding device of the material for out finish forged crankshaft.
[Requested item 7]
　In the process of producing the forged crankshaft for 3-cylinder engine, an apparatus for molding a material for out finishing subjected to finishing strike to shape the final shape of the forged crankshaft
　journal portion and the axial length of the forged crankshaft the same roughness journal portion of the pin portion and the axial length is the same coarse pin portion of the forged crankshaft, and a thick crude crank arm portion axial thickness than the crank arm portion of the forged crankshaft is shaped respectively from a crude material, an apparatus for molding a material for out finishing,
　among the rough pin portion of the crude material, the first ends, third coarse pin portion opposite directions eccentricity of the axial direction perpendicular to each other in a smaller than √3 / 2 of the eccentricity of the pin portion of the forged crankshaft, a second coarse pin portion of the central, axially perpendicular direction of eccentricity is zero or first, third coarse forging in the direction perpendicular to the eccentric direction of the pin portion Eccentricity of the pin portion of the rank shaft are the same,
　the molding apparatus,
　is disposed at a position of the second coarse pin portion, with addressed cracking in the coarse pin, crude crank connected to the rough pin portion while contacting the side surface of the arm portion, and the reference pin-type which are constrained to move in the axial direction,
　the first, is disposed in the third coarse pins of each position, the addressed cracking each said coarse pin portion, are each while in contact with the side surface of the rough crank arm portion leading to the rough pin portion, and a movable pin type which moves in the axial direction and the axial direction perpendicular to a direction toward the reference pin-type,
　disposed rough journal portions of each position, moving the coarse journal portion holds individually sandwiches from the axial direction and perpendicular, while each in contact with the side surface of the rough crank arm portion leading to the rough journal portion, in the axial direction toward the reference pin-type With that journal type and, the,
　The crude journal portion held sandwiched in the journal-type, the reference pin-type and movable pin type from destined wants state to the rough pin moves the journal-type axially moving the movable pin type axially by moving in the axial direction and perpendicular with, the crude crank arm portion nipped in the axial direction together with reducing its thickness to a thickness of the crank arm portion of the forged crankshaft, first, a third coarse pin portion pressed in opposite directions in the axial direction perpendicular to the direction that increases the eccentricity to √3 / 2 of the eccentricity of the pin portion of the forged crankshaft, material for striking finish forging crankshaft for 3-cylinder engine molding apparatus.
[Requested item 8]
　In the molding apparatus according to claim 7,
　wherein the reference pin-type and the movable pin type, is arranged outside the opposite to the reference pin-type and said side movable pin type is We have addressed in each of the coarse pin portion and it includes an auxiliary pin-type,
　the journal-type, and the moves to an auxiliary pin-type axial direction forming the movable pin type and the movable pin type paired with the journal-type, the reference pin-type , after the gap between the movable pin type and the auxiliary pin type it is closed, so that the rough pin portion for pressing deformation reaches the auxiliary pin-type, in the axial direction perpendicular to the direction of the movable pin type movement is controlled, the molding apparatus of the material for out finish forging crankshaft for 3-cylinder engine.
[Requested item 9]
　In the molding apparatus according to claim 8,
　when the total distance in the axial direction perpendicular to the direction of the movable pin type as 100%, the movement in the axial direction of the journal-type adjacent to the movable pin type Upon completion, it is moved a distance in the axial direction perpendicular to the direction of the movable pin type than 90% of the total distance, the movement in the axial direction perpendicular to the direction of the movable pin type after the complete , material forming apparatus for beating finish forging crankshaft for 3-cylinder engine.
[Requested item 10]
　In the molding device according to any one of claims 7-9,
　wherein the reference pin-type, the movable pin type and the journal type is attached to the pressing in a direction along the axial direction and perpendicular capable press and,
　with the pressure of the press, along with the journal type holds sandwich the crude journal portion, addressed to cracking on the reference pin-type and the movable pin type the rough pin portion, reduction of intact press with to continue, at the same time when the journal type is moved in the axial direction by individually wedge mechanism, along with the movement of the journal type, the movable pin type individually moving in the axial direction, for 3-cylinder engine molding device of the material for out finish forged crankshaft.
[Requested item 11]
　In the molding apparatus according to claim 10,
　the wedge angle of the wedge mechanism are different from each other in each of the journal-type, the molding device of the material for out finish forging crankshaft for 3-cylinder engine.
[Requested item 12]
　In the molding apparatus according to claim 10 or 11,
　wherein is movable pin type is connected to the hydraulic cylinder, it is moved by driving the hydraulic cylinder in the axial direction and perpendicular, finish forging crankshaft for 3-cylinder engine molding apparatus of the material for the strike.
[Requested item 13]
　3 A method of manufacturing a forged crankshaft for cylinder engine,
　the manufacturing method includes a first preforming step described below, the second preforming step, and the finishing beating process, the series of steps:
　claim 1 as the coarse material to be subjected to molding apparatus according to any one of 1 to 6, among the rough pin portion, the first ends, third coarse pin portion opposite directions eccentricity of the axial direction perpendicular to each other in is the same as √3 / 2 of the eccentricity of the pin portion of the forged crankshaft, a second coarse pin portion of the central, first eccentricity of the axial perpendicular direction, the third coarse pin portion first preforming step shaping the crude material that is smaller than the eccentricity of the pin portion of the forged crankshaft in a direction perpendicular to the direction of eccentricity;
　using the molding apparatus according to any one of claims 1 to 6, as the finishing out material for the final shape of the shaped forged crankshaft including an arrangement angle of the pin portion Second preforming step to mold the material for finishing out were; and
　said finishing material for out and out finishing, finishing beating process the final shape of the forged crankshaft including an arrangement angle of the pin portion is molded finish which is shaped .
[Requested item 14]
　A method of manufacturing a forged crankshaft for 3-cylinder engine,
　the manufacturing method includes a first preforming step described below, the second preforming step, finishing beating process, and twisting process, a series of steps of:
　as the coarse material to be subjected to molding apparatus according to any one of claims 1 to 6, among the rough pin portion, the first ends, third coarse pin portion, eccentricity of the axial perpendicular direction is smaller than the eccentricity of the pin portion of the forged crankshaft in the same direction, the second coarse pin portion of the central, axial and amount of eccentricity perpendicular first, eccentric direction of the third coarse pin portion first preforming step shaping the crude material that is smaller than the eccentricity of the pin portion of the forged crankshaft in the opposite direction;
　a molding device according to any one of claims 1 to 6 using, for the finishing out as the material, specification final shape of the forged crankshaft except placement angle of the pin portion is shaped Second preforming step to mold the material for out;
　the finishing material for out and out finishing, finishing beating process the final shape of the forged crankshaft except placement angle of the pin portion is molded finish that is shaped; and
　the twisting step of adjusting the arrangement angle of the pin portion of the finish to the arrangement angle of the pin portion of the forged crankshaft.
[Requested item 15]
　3 A method of manufacturing a forged crankshaft for cylinder engine,
　the manufacturing method includes a first preforming step described below, the second preforming step, and the finishing beating process, the series of steps:
　7. as the coarse material to be subjected to molding apparatus according to any one of 1 to 12, among the rough pin portion, the first ends, third coarse pin portion opposite directions eccentricity of the axial direction perpendicular to each other in a smaller than √3 / 2 of the eccentricity of the pin portion of the forged crankshaft, a second coarse pin portion of the central, shaping the crude material eccentricity of the axial perpendicular direction is zero first preforming step;
　using the molding apparatus according to any one of claims 7 to 12, as the finishing out for materials, of the crude pin portion, the first, third coarse pin portion at both ends, the axial and the pin portion of the forged crankshaft in the opposite direction eccentricity of perpendicular to each other eccentricity amount of √ / 2 and is the same, the second coarse pin portion of the central, second preforming step eccentricity of the axial direction perpendicular to the molding material for striking finish that is to remain the same as the coarse material; and
　the first ends of the material for the finishing out, and striking finish while the third coarse pin unit in a horizontal posture to press all the crude pin portion axially perpendicular direction, the arrangement angle of the pin portion finishing beating process the final shape of the forged crankshaft including to molding a finish that is shaped.
[Requested item 16]
　3 A method of manufacturing a forged crankshaft for cylinder engine,
　the manufacturing method includes a first preforming step described below, the second preforming step, and the finishing beating process, the series of steps:
　7. as the coarse material to be subjected to molding apparatus according to any one of 1 to 12, among the rough pin portion, the first ends, third coarse pin portion opposite directions eccentricity of the axial direction perpendicular to each other in a smaller than √3 / 2 of the eccentricity of the pin portion of the forged crankshaft, a second coarse pin portion of the central, first eccentricity of the axial perpendicular direction, the third coarse pin portion first preliminary molding step to shape the same into the coarse material and eccentricity of the pin portion of the forged crankshaft in a direction perpendicular to the direction of eccentricity;
　using the molding apparatus according to any one of claims 7 to 12, as the finishing out for materials, of the crude pin portion, the first, third coarse pin portion at both ends, the shaft Eccentricity of direction and perpendicular direction is the same as √3 / 2 of the eccentricity of the pin portion of the forged crankshaft in directions opposite to each other, the second coarse pin portion of the central, axial direction perpendicular and; eccentricity second preforming step for forming the same leave been finishing out for materials and the crude material
　in a state where the first ends of the finishing out for material and the third coarse pin unit in a horizontal posture and out finishing, first, third coarse pin portion is pressed in the axial direction and perpendicular to, finishing beating process the final shape of the forged crankshaft including an arrangement angle of the pin portion is molded finish that is shaped.