Technical field
[0001]
　The present invention relates to an apparatus for manufacturing a crank shaft by hot forging.
Background technique
[0002]
　Automobiles, motorcycles, agricultural machines, the reciprocating engine such as a marine vessel, in order to convert the reciprocating motion of the piston into rotational movement takes power, the crankshaft is essential. Crankshaft can be produced by die forging or casting. When the high strength and high rigidity are required to the crankshaft, forged crankshaft manufactured by forging is widely used.
[0003]
　Generally, in the manufacture of forged crankshaft, and the billet raw material. In that billet cross-section is round or square cross-sectional area is constant over the entire length. Manufacturing process of forging the crank shaft includes preforming step, the mold forging step, a burr punching process. If correction is needed, add a shaping step after the Bali punching process. Usually, preforming step includes a roll forming process and the bending beating process, the mold forging step includes a rough beating step and finishing beating process.
[0004]
　Figure 1A ~ FIG. 1F is a schematic diagram for explaining a conventional general forged crankshaft manufacturing process. Crankshaft 1 illustrated in FIG. 1F is mounted on four-cylinder engine, a crankshaft of a four-cylinder -8 sheets counterweight. As the crank shaft 1, the five journal portions J1 ~ J5,4 one pin portions P1 ~ P4, the front portion Fr, flanges Fl, and eight of the crank arm portion (hereinafter, simply referred to as "arm") A1 consisting of ~ A8. Each arm portion A1 ~ A8 is, connecting the journal portion J1 ~ J5 and the pin portion P1 ~ P4. Also, all of the arms A1 ~ A8 of eight, the counterweight unit (hereinafter, simply referred to as "weight part") having W1 ~ W8 integrally.
[0005]
　Four pin portions P1 ~ P4 are both eccentric with respect to the journals J1 ~ J5. Phase of the pin portion P1 ~ P4 is appropriately set so as to be plane-symmetrical about the longitudinal center of the journal portion J3 of the crankshaft 1. Thus, the arm portions A4, A5 connected with a central journal section J3 becomes plane-symmetrical about the journal portion J3. That is, the two arm portions A4, A5 are both connected with the same phase pin P2, P3 along with leading the same journal portion J3.
[0006]
　Hereinafter, when collectively each journal portion J1 ~ J5, pin P1 ~ P4, the arm portions A1 ~ A8, and the weight portion W1 ~ W8, the sign, in the journal portion "J", a pin portion "P" , also referred to as "a", "W" in the weight portion in the arm portion. Together a pair of arm portions A (including the weight portion W) which leads to the pin portion P and the pin portion P is also referred to as "slow".
[0007]
　In the manufacturing method shown in FIGS. 1A ~ FIG 1F, forged crankshaft 1 is manufactured as follows. First, after heating the predetermined length of the billet 2, as shown in FIG. 1A by a heating furnace (e.g., an induction heating furnace or gas heating furnace), and roll forming. The roll forming process, squeeze rolling a billet 2 using, for example, grooved roll. Thus, allocating the volume of the billet 2 in the longitudinal direction to obtain a roll wasteland 3 is an intermediate material (see FIG. 1B). Next, in the bending beating process, partially reduction roll wasteland 3 longitudinally from a vertical direction. Thus, allocating the volume of the roll wasteland 3, it is a further intermediate material bending obtain wasteland 4 (see FIG. 1C).
[0008]
　Subsequently, the rough beating step, by reduction using a pair of molds bending wasteland 4 vertically to obtain a rough forged material 5 (see FIG. 1D). Rough forged material 5 has the approximate shape of a crank shaft (final product). Furthermore, the finishing beating process, obtaining a finish forged material 6 by reduction using a pair of molds rough forged material 5 up and down (see FIG. 1E). Finishing forged material 6 having a substantially matching shape to the crankshaft of the final product. In these rough beating and finishing beating process, excess material flows out from between the parting surface of the mold facing each other, the burr. Therefore, the rough forging 5 and the finishing forging 6, burrs 5a, 6a are attached largely around the shape of the crankshaft.
[0009]
　In Bali punching step, for example, the finish forged material 6 with burrs 6a while holding a pair of molds, punching burrs 6a by blade type. Thus, to remove the burrs 6a from the finishing forging 6. In this manner, forging burr is removed can be obtained. Forging burr is removed is substantially the same shape as the forged crankshaft 1 shown in FIG. 1F. Forging burr has been removed, a plurality of journal portions J of the forged crankshaft, a plurality of pin portion P, and corresponds to each of the plurality of arm portions A and the weight portion W, a plurality of rough journal portions J ', a plurality of crude pin portion P ', the plurality of coarse crank arm a' comprises and coarse weight portion W '.
[0010]
　The shaping step, slightly rolling the mold burr key points forging removed from above and below to correct forging burrs have been removed to the size shape of the final product. Here, the key point of forging burr has been removed, for example, crude journal portion J is a 'rough pin portion P', rough arm A 'and the coarse weight portion W'. Furthermore, the key point of the forging burr has been removed, the front section Fr, and the crude front portion corresponding to the shaft portion, such as flange portion Fl of the crank shaft, and a shaft portion of such crude flange. Thus, forged crankshaft 1 is manufactured.
[0011]
　Manufacturing process shown in FIGS. 1A ~ FIG 1F is not limited to the crank shaft of a four-cylinder -8 Like counterweight shown in Fig. 1F, it can be applied to various crankshaft. For example, the manufacturing process shown in FIGS. 1A ~ FIG. 1F can be applied to the crankshaft of a four-cylinder -4 Like counterweight.
[0012]
　Figure 2 is a schematic diagram showing a configuration example of a crankshaft of a four-cylinder -4 Like counterweight. The crankshaft of a four-cylinder -4 Like counterweight shown in FIG. 2, the top first arm A1 of the eighth arm portion A8 rearmost, and two arm portions of the center (the fourth arm portion A4, the 5 arm A5) weight portion W1, W4, W5, W8 is provided integrally. Further, the remaining arm portions A2, A3, A6, A7 has no weight portion.
[0013]
　Manufacturing process shown in FIGS. 1A ~ FIG. 1F, 3-cylinder engine, series 6-cylinder engine, V-type 6-cylinder engine, even crankshaft mounted in eight-cylinder engine or the like can be applied. Incidentally, when the adjustment of the arrangement angle of the pin portion is required, after the burr punching process, twisting process is added.
[0014]
　Recently, in particular reciprocating engine for motor vehicles, weight reduction is demanded in order to improve fuel economy. Therefore, also the crank shaft mounted on a reciprocating engine, the weight reduction request is remarkably. As a conventional art to reduce the weight of the forged crankshaft, there is the following.
[0015]
　Patent Documents 1 and 2, the arm portion hole in the surface of the journal portion is formed is described. Method for producing a crankshaft having an arm portion which is formed a hole portion are also described. Hole of the arm portion, the straight line connecting the axial center of the axis and the pin portion of the journal portion (hereinafter, also referred to as "arm center line") is molded on, recessed deeper toward the pin portion. Thus, the volume fraction of the hole, the arm portion is lightweight. Weight of the arm leads to weight reduction of the weight portion constituting the arm portion and the pair thus leading to reduction in the overall weight of the forged crankshaft. The arm portion hole is formed, since the thickness in both sides of the pin in the vicinity between which arm center line is thick, rigidity (torsional rigidity and flexural rigidity) is ensured.
[0016]
　In this way, increasing the thickness of the side portions of the arm portions, if no dent in the surface of the journal portion of the arm portion, can be reduced weight and rigidity ensuring at the same time.
[0017]
　However, forged crankshaft having an arm portion of such unique shape is difficult to manufacture by conventional manufacturing methods. In die forging process, if an attempt forming a recess in the arm portion surface, because the type draft mold recessed portion is reversed gradient. In this case, a situation that shaped forging can not escape from the mold occurs.
[0018]
　To cope with such a situation, in the production method described in Patent Documents 1 and 2, in the die forging process, forming small arm without forming a recess in the arm surface. Further, after the burr punching step, pushing a punch on the surface of the coarse arm, forming a recess by traces of the punch.
CITATION
Patent Literature
[0019]
Patent Document 1: JP 2012-7726 JP
Patent Document 2: JP 2010-230027 JP
Summary of the Invention
Problems that the Invention is to Solve
[0020]
　According to the manufacturing method described in Patent Documents 1 and 2, by forming a recess in the surface of the journal portion of the arm portion, it is possible to increase the thickness of the side portions of the arm portions. This allows manufacturing a forged crankshaft which attained weight and rigidity ensuring at the same time.
[0021]
　However, in the manufacturing method of Patent Document 1 and 2, in order to mold the recess in the arm portion surface, to deform the entire strongly pushed by the coarse arm punch to rough arm surface. Therefore, it takes a great deal of force to push the punch. Therefore, special equipment configuration for imparting a great deal of force to the punch is required, it is necessary to consider with respect to durability of the punch.
[0022]
　Accordingly, the present inventors have, PCT / JP2014 / 005835 (hereinafter, referred to as "Patent Document 3") in, by folding the excess thickness portion was proposed to forming a recess in the surface of the journal portion of the arm portion . Specifically, in the die forging process, forming a forged material having an excess thickness portion protruding from both side portions respectively of the outer periphery of the rough pin portion near the coarse arm. In shaping step, folding the excess thickness portion by a pair of molds with vertical toward the rough journal portion of the surface of the coarse arm. In this case, in order to shape the recess may be necessary to impart a great deal of force without obtaining a forged crankshaft which attained weight and rigidity ensuring at the same time conveniently.
[0023]
　In Patent Document 3, in shaping processes, when bending toward the excess thickness portion to the rough journal portion of the surface of the coarse arm portion, the area of ​​both sides among the rough journal portion of the surface of the coarse arm the surface except proposed to hold by abutting the tool. Thus, the shape of both side portions of the arm portion, can be precisely shaped.
[0024]
　Further, in PCT / JP2014 / 005850 (hereinafter referred to as "Patent Document 4"), and proposed that crushed instead of bending. Specifically, by crushing the excess thickness portion by a pair of molds in vertical, it proposed to forming a recess in the surface of the journal portion of the arm portion. Any patent document 4, when crushing the excess thickness portion, the surface except the regions on both sides among the rough journal portion of the surface of the coarse arm, proposed to hold by abutting the tool.
[0025]
　However, it tends to become insufficient movable range for the contact with the tool on the surface of the rough journal portion of the crude arm. In particular, when contacting a tool to the coarse arm in a plane symmetrical with respect to the crude journal portion, the movable range of the tool is insufficient easily. The reason will be described with reference to FIGS. 3A ~ Figure 3E.
[0026]
　Figure 3A ~ 3E are the plane-symmetrical two coarse arm is a schematic view showing a moving mechanism of the tool when in contact with the tool on the surface thereof rough journal portion skilled. Figure 3A is a top view showing the positional relationship between the forging and the tool, FIG. 3B is a perspective view of the movable mechanism, FIG. 3C is a top view when the tool is in the contact position, FIG. 3D when the tool is in the retracted position top view of FIG. 3E is a sectional view taken along the IIIE-IIIE line in FIG. 3C. Movable mechanism includes a mold 10, two tool 92, a jig 93. In order to facilitate understanding of the drawing, FIG and FIG 3A 3E, not shown of the mold 10. FIG 3B ~ FIG 3D, showing a portion of a lower mold half 10. FIG 3A, shows a forging material used in the manufacture of a crankshaft of a four-cylinder -4 Like counterweight.
[0027]
　In Figure 3A, showing 'the case that faces the jig 93 is the third coarse journal portion J3' jig 93 and the second rough journal J2 and the case facing the. As shown in FIG. 3A, the tool 92 has its front end surface 92a abuts against the forging during the shaping process. The distal end surface 92a of the tool, is reflected shaped to conform to the surface of the journal portion of the arm portion. To accommodate the tool 92, the mold 10 has an open portion 10b is provided groove-like tool (see FIG. 3B).
[0028]
　During shaping process, the tool 92 is disposed in the contact position, as shown in FIG. 3C. Further, when loading of the shaping process before forging, and, at the time of unloading of the forging material after shaping processing, in order to separate the the tool 92 and the forging tool 92 is placed at the retracted position as shown in FIG. 3D that. Note that FIG. 3D, shows the shape of the front end surface of the tool at the abutment position by a two-dot chain line.
[0029]
　When the tool 92 is moved from the retracted position to the contact position, the tool 92 is moved along both sides 92b of both side surfaces and the tool 92 of the groove-shaped tool opening 10b (the solid line in FIG. And FIG. 3C 3D see arrows). That is, both side surfaces of the groove-shaped tool opening 10b and both side surfaces 92b of the tool 92 functions as a guide portion.
[0030]
　The tool 92 is held by the jig 93. Its jig 93 is accommodated in a groove-like jig opening of the mold 10. Further, the jig 93 is connected to a driving device (not shown), it is movable along the eccentric direction of the pin portion by the actuation of the drive unit (see arrows hatched in FIG. 3C).
[0031]
　The jig 93 is movably holding the tool 92. Jig 93 shown in FIGS. 3A ~ 3E are the movable tool 92 along the sliding direction (see broken line arrows in FIG. And FIG. 3C 3D). Therefore, the jig 93 includes a convex portion 93a extending along the sliding direction on the upper and lower surfaces. The convex portions 93a, as in the groove-shaped tool opening 10b of the die 10 is provided as a guide portion. Also, to accommodate the convex portion 93a of the jig on the back of the tool 92 (the surface of the front end face 92a opposite), as shown in FIG. 3E, the groove 92d is provided with recesses 92c.
[0032]
　Depending on the jig 93 is moved along the eccentric direction of the pin portion, the tool 92 is moved along the guide portion. Here, the movement of the sliding direction of the tool 92 is constrained by both side surfaces and both side surfaces 92b of the tool 92 of the groove-shaped tool opening 10b. Therefore, the jig 93 as it moves along the eccentric direction of the pin portion, the tool 92 is moved relative to the sliding direction with respect to the jig 93.
[0033]
　Here, in the crank shaft, as shown in FIG. 1F and Fig. 2, the arm portion A is provided with a plurality along a longitudinal direction of the crankshaft. For this reason, the space for placing the tool is narrow. Further, the movable mechanism of the tool shown in FIGS. 3A ~ Figure 3E, since the guide portion both sides 92b of the tool 92, the width of the tool is increased. These tool 92 tends to interfere with the jig 93 and the die 10, the movable range of the tool is insufficient. Therefore, after the shaping process, when unloading the forged material in the state in which the tool 92 to the retracted position, interfere with the tool 92 and the forging, out of shaping machined forging is difficult.
[0034]
　In particular, when the tool abuts against the two arm portions face symmetrically around the journal portion, it is necessary to arrange the two tools between the two arm portions, easy two tools interfere with each other. Therefore, the movable range of the tool is more insufficient.
[0035]
　An object of the present invention, when performing processing of deforming the excess thickness portion of the forging burr has been removed, can be secured the movable range of the tool, machined forging a smoothly unloaded forged crankshaft manufacturing apparatus It is to provide a.
Means for Solving the Problems
[0036]
　Apparatus for manufacturing a forged crankshaft according to an embodiment of the present invention, in the process of manufacturing forged crankshaft, subjected to processing in forging burr is removed. Forged crankshaft has a plurality of journal portion as a rotational center, and a plurality of pin portions eccentric to the journal portion, and a plurality of crank arm connecting the journal portion and the pin portion. At least a portion of the crank arm portion of the plurality of crank arm portion of the forged crankshaft has a counterweight portion integrally. Forging, a plurality of journal portions of the forged crankshaft, a plurality of pin portions, corresponding to a plurality of crank arm and the counterweight unit, a plurality of rough journal portion, a plurality of coarse pin portions, a plurality of coarse crank arm It comprises parts and crude counterweight unit. At least a portion of the crude crank arm portion of the plurality of coarse crank arm portion has a first excess thickness portion projecting from the outer periphery of the rough pin portion near the side.
[0037]
　Apparatus for manufacturing a forged crankshaft is provided with a pair of molds in vertical, the first tool, the. Mold, subjected to processing to increase the thickness of the side portion of the crude pin portion near the first excess thickness portion to deform the crude crank arm. The first tool is housed in the opening portion of the mold, in contact with the surface except for the area of ​​the rough pin portion near the side among the rough journal portion of the surface of the rough crank arm. Mold and the first tool has a first guide portion for guiding the first tool to the contact position from the retracted position, respectively. At least one of the upper and lower surfaces of the first tool, the first guide portion is provided.
Effect of the invention
[0038]
　Apparatus for manufacturing a forged crankshaft of the present invention comprises a first tool in contact with the surface of the journal portion of the arm portion. The first tool, the first guide portion is provided on at least one of its upper and lower surfaces. Therefore, by changing the side shape of the first tool appropriately, first tool is prevented from interfering with the jig and the mold can be moved in a sufficient range of the first tool.
BRIEF DESCRIPTION OF THE DRAWINGS
[0039]
[Figure 1A] Figure 1A is a schematic diagram showing the billet in conventional general forged crankshaft manufacturing process.
FIG 1B] Figure 1B is a schematic diagram showing a roll wasteland in a conventional typical forged crankshaft manufacturing process.
[Figure 1C] Figure 1C is a schematic diagram showing a wasteland bending in a conventional typical forged crankshaft manufacturing process.
[Figure 1D] Figure 1D is a schematic diagram showing a rough forged material in a conventional typical forged crankshaft manufacturing process.
FIG 1E] FIG. 1E is a schematic diagram showing a finishing forging material in a conventional typical forged crankshaft manufacturing process.
[FIG. 1F] FIG. 1F is a schematic diagram showing a crankshaft in a conventional typical forged crankshaft manufacturing process.
FIG. 2 is a schematic diagram showing a configuration example of a crankshaft of a four-cylinder -4 Like counterweight.
[Figure 3A] Figure 3A is a top view showing the positional relationship between the forging and the tool.
[Figure 3B] Figure 3B is a perspective view schematically showing a moving mechanism of the tool.
FIG 3C] Figure 3C is a top view schematically showing the case where the tool is in the contact position.
[Figure 3D] Figure 3D is a top view showing the case where the tool is in the retracted position schematically.
FIG 3E] Figure 3E is a cross-sectional view at IIIE-IIIE line in FIG. 3C.
[Figure 4A] Figure 4A is a perspective view schematically showing the arm portion shape of a crank shaft of the first configuration example of the present invention.
[Figure 4B] Figure 4B is a front view schematically showing the arm portion shape of a crank shaft of the first configuration example of the present invention.
[Figure 4C] Figure 4C is a side view schematically showing the arm portion shape of a crank shaft of the first configuration example of the present invention.
[FIG. 4D] FIG. 4D is a cross-sectional view at IVD-IVD line in Figure 4B.
[Figure 5A] Figure 5A is a perspective view schematically showing a rough arm portion shape of the first configuration example of the burr has been removed forged material of the present invention.
[Figure 5B] Figure 5B is a front view schematically showing a rough arm portion shape of the first configuration example of the burr has been removed forged material of the present invention.
[Figure 5C] Figure 5C, the coarse arm portion shape of the forging burr of the first configuration example is the removal of the present invention is a side view schematically showing.
[Figure 5D] Figure 5D is a cross-sectional view at VD-VD line in Figure 5B.
[Figure 6A] Figure 6A is a front view schematically showing the arm portion shape of a crank shaft of the second configuration example of the present invention.
[Figure 6B] Figure 6B is a cross-sectional view at line VIB-VIB in FIG. 6A.
[Figure 7A] Figure 7A is a front view schematically showing a rough arm portion shape of the second configuration example of the burr has been removed forged material of the present invention.
[Figure 7B] Figure 7B is a cross-sectional view at line VIIB-VIIB in FIG. 7A.
[FIG. 8A] Figure 8A is a perspective view schematically showing an apparatus for manufacturing a forged crankshaft of the present embodiment.
[Figure 8B] Figure 8B is an enlarged perspective view showing an apparatus for manufacturing a forged crankshaft of the present embodiment as seen from an arrow direction in FIG. 8A schematically.
[Figure 8C] Figure 8C is a top view of a case of the tool in the apparatus for manufacturing a forged crankshaft of the present embodiment is in the contact position.
[Figure 8D] Figure 8D is a top view when the tool is in the retracted position in the production apparatus of forging the crank shaft of the present embodiment.
[9] FIG. 9 is a schematic view showing a configuration example of an apparatus for manufacturing a forged crankshaft of the present invention different from that of FIG. 8A ~ Figure 8D.
[10] FIG 10 is a top view showing the positional relationship between the tool and the forging material of the present embodiment.
FIG 11A] FIG 11A is a manufacturing apparatus for forging a crankshaft of the present embodiment, further comprising a second tool is a top view of a case where the second tool is in the contact position.
FIG 11B] FIG 11B is a manufacturing apparatus for forging a crankshaft of the present embodiment, further comprising a second tool is a top view of a case where the second tool is in the retracted position.
DESCRIPTION OF THE INVENTION
[0040]
　Apparatus for manufacturing a forged crankshaft of the present embodiment, in the process of manufacturing forged crankshaft, subjected to processing in forging burr is removed. Forged crankshaft has a plurality of journal portion as a rotational center, and a plurality of pin portions eccentric to the journal portion, and a plurality of crank arm connecting the journal portion and the pin portion. At least a portion of the crank arm portion of the plurality of crank arm portion of the forged crankshaft has a counterweight portion integrally. Forging, a plurality of journal portions of the forged crankshaft, a plurality of pin portions, corresponding to a plurality of crank arm and the counterweight unit, a plurality of rough journal portion, a plurality of coarse pin portions, a plurality of coarse crank arm It comprises parts and crude counterweight unit. At least a portion of the crude crank arm portion of the plurality of coarse crank arm portion has a first excess thickness portion projecting from the outer periphery of the rough pin portion near the side.
[0041]
　Apparatus for manufacturing a forged crankshaft is provided with a pair of molds in vertical, the first tool, the. Mold, subjected to processing to increase the thickness of the side portion of the crude pin portion near the first excess thickness portion to deform the crude crank arm. The first tool is housed in the opening portion of the mold, in contact with the surface except for the area of ​​the rough pin portion near the side among the rough journal portion of the surface of the rough crank arm. Mold and the first tool has a first guide portion for guiding the first tool to the contact position from the retracted position, respectively. At least one of the upper and lower surfaces of the first tool, the first guide portion is provided.
[0042]
　Forged crankshaft manufacturing apparatus of further comprises a first jig movable along the eccentric direction of the pin portion is preferred. The first jig, the first tool, respectively, preferably movably held in the first sliding direction with a first guiding direction and angle along the first guide portion. The first tool is to rough the crank arm portion, preferably in contact with the surface except for the area of ​​the rough pin portion near the side of the coarse journal portion. The first tool is preferably moved along the first guide direction with the movement of the first jig.
[0043]
　In the manufacturing apparatus of the forged crankshaft, all of the crank arm portion of the forged crankshaft may have a counterweight portion integrally.
[0044]
　If some of the crank arm portion of the forged crankshaft has a counterweight portion, the manufacturing apparatus of forging the crank shaft may be configured as follows.
[0045]
　At least a portion of the crude crank arm portion of the crude crank arm portion having no crude counterweight portion of forging further comprises a second excess thickness portion projecting from the outer periphery of the rough journal portion near the side. The mold further subjected to processing to increase the thickness of the side portion of the crude journal portion near the second excess thickness portion to deform the no coarse counterweight portion crude crank arm. Forged crankshaft manufacturing apparatus is housed in the opening portion of the mold. Manufacturing apparatus further comprises a second tool. The second tool is in contact with the surface except for the area of ​​the rough journal portion near the side among the rough pin portion of the surface of the rough crank arm portion having no crude counterweight unit. Mold and the second tool has a second guide portion for guiding the second tool to the contact position from the retracted position, respectively. At least one of the upper and lower surfaces of the second tool, the second guide portion is provided.
[0046]
　Mold of the manufacturing apparatus is preferably a mold subjected to shaping processing to the forging material.
[0047]
　Hereinafter, the apparatus for manufacturing a forged crankshaft of the present embodiment will be described with reference to the drawings.
[0048]
1. The shape of the crankshaft
　forged crankshaft embodiment is directed includes a journal portion as a rotational center, and a pin portion which is eccentric with respect to the journal portion, and an arm portion connecting the journal portion and the pin portion. Forged crankshaft plurality have a respective journal portion, the pin portion and the arm portion. At least a portion of the arm portion of the plurality of arm portions of the forged crankshaft has a weight portion integrally. All of the arm portion of the forged crankshaft may have a weight portion integrally. Such forged crankshaft, can be adopted forged crankshaft of the first configuration example shown in FIG. 4A ~ Figure 4D. It is also possible to employ a forged crankshaft of the second configuration example shown in FIG. 6A and 6B.
[0049]
　Forged crankshaft of the first configuration example and second configuration example are both dents are provided on the surface of the journal portion of the arm portion. Forged crankshaft of the second configuration example, an arm portion having no weight portion. Also depressions on the surface of the pin portion is provided in the arm portion without the weight portion.
[0050]
　FIGS. 4A ~ 4D are schematic views showing the arm portion shape of a crankshaft of the shaped working in a first configuration of the present invention. Figure 4A is a cross-sectional view of a perspective view, FIG 4B is a front view as viewed from the journal portion, FIG. 4C is a side view, FIG. 4D IVD-IVD line in Figure 4B. In Figure 4A ~ Figure 4D, it is representatively shown to extract one of the arm portion of the crank shaft (including the weight portion) is omitted and the remaining arm. Further, FIG. 4C is a diagram viewed from a direction indicated by a dotted arrow in FIG. 4B.
[0051]
　Arm A of the first configuration example, as shown in FIGS. 4A ~ Figure 4D, of the surface of the journal portion J side, both side portions Aa of the pin portion near P, inside the area As of Ab, has a recess. Further, both side portions Aa, Ab of the pin portion near P overhangs the journal portion J side. Both side portions Aa, the thickness of the Ab as compared to the thickness of the recess of As that is an inner area, a thick.
[0052]
　Arm A of this first configuration example, both side portions Aa of the pin portion near P, with the thickness of the Ab is thick, depressions on the surface of the journal portion J side is formed. Therefore, forging a crankshaft according to the present embodiment, it is possible to reduce the weight of the recess of the arm portion A. In addition, both side portions Aa of the arm A, it is possible to secure the rigidity by increasing the thickness of the Ab.
[0053]
　In the first configuration example, a case side portions Aa of the pin portion near P of the arm A, the thickness of the Ab thick. However, it may be thicker the thickness of only one side of the pin portion near P of the arm A. Even in this case, the rigidity of the arm portion for the thickness of the pin portion P near the sides of the arm A is thick is ensured.
[0054]
　FIGS. 5A ~ 5D are schematic diagrams showing a rough arm portion shape of the first burr before shaping processing in the configuration examples have been removed forged material of the present invention. Figure 5A is a cross-sectional view of a perspective view, FIG. 5B is a front view as viewed from a crude journal side, Figure 5C is a side view, VD-VD line in FIG. 5D in Figure 5B. In Figure 5A ~ FIG 5D, it shows with typical extract one coarse arm forging (including crude weight portion) is omitted and the remaining crude arm. Further, FIG. 5C is a view seen from the direction indicated by broken line arrows in FIG. 5B. The FIG. 5D, for easy understanding of the drawing shows a first tool 20 and the jig 30 of the manufacturing apparatus of this embodiment described below.
[0055]
　Crude arm A before shaping process', as shown in FIG. 5A ~ FIG 5D, rough journal portion J 'of the side surface, rough pin portion P' sides Aa near ', inner region of Ab' As to have a surface shape that matches the final product shape after shaping process. Its surface shape extends smoothly to a region of the coarse pin portion P 'sides Aa near', Ab '. Accordingly, both side portions Aa ', Ab' thickness is thinner than the thickness of the final product after shaping process.
[0056]
　Furthermore, crude pin portion P 'sides Aa near', the Ab ', the first excess thickness portion Aaa projecting from the respective outer peripheral has Aba. The first excess thickness portion Aaa, Aba is a plate-like, coarse pin portion P 'sides Aa near' are provided along the outer periphery of Ab '. The first excess thickness portion Aaa, the thickness of Aba is both side portions Aa of the root ', Ab' than the thickness of, or is thin comparable.
[0057]
　The forging of the first configuration example, all the crude arm A 'is first excess thickness portion Aaa, may have Aba. A part of the crude arm A 'is first excess thickness portion Aaa, it may have Aba. In a first configuration example illustrates the case where coarse arm A 'has two first excess thickness portion Aaa, the Aba. However, coarse arm A 'may have only first excess thickness portion of one. In this case, the thickness of one side of the pin portion near the arm portion of the crank shaft produced becomes thick.
[0058]
　6A and 6B are schematic views showing the arm portion shape of a crankshaft of the shaped working in a second configuration example of the present invention. Figure 6A is a front when viewed from the pin side view, FIG. 6B is a sectional view taken along the line VIB-VIB in FIG. 6A. Crankshaft of the second configuration example has a plurality of arm portions, the weight portion is provided on the arm portions of some of them. FIG 6A and 6B, is shown as a representative to extract one of the arm portions weight portion is not provided, it is omitted arm of the remaining crankshaft.
[0059]
　Arm A of the second configuration example, although not shown, as in the first configuration example described above, with the thickness of the side portions of the pin portion near P is thick, depressions on the surface of the journal portion J side is formed ing. In addition, the arm portion A having no weight portion of the second configuration example, as shown in FIGS. 6A and 6B, of the pin portion P side of the surface, the journal portion J on both sides of the vicinity of Ac, inner Ad the area At, has another recess. Further, the journal portion J vicinity of both side portions Ac, Ad is projecting the pin portion P side. Their sides Ac, Ad thickness as compared to the thickness of the recess is thick.
[0060]
　Such arm A of the second configuration example, with the thickness of the side portions of the pin portion near P is thick, depressions on the surface of the journal portion J side is formed. Arm A having no weight unit further journal portion J vicinity of both side portions Ac, together with the thickness of the Ad is thick, another recess is formed on the surface of the pin portion P side. Therefore, forging crankshaft according to the second configuration example, it is possible to further reduce the weight of the journal portion J side of the arm portion A and the pin portion P side of the two recessed. In addition, it is possible to secure rigidity by the pin portion P near the sides and the journal portion J vicinity of both side portions Ac, Ad is thicker.
[0061]
　In the second configuration example, a case both sides of the side portions and journal portions J vicinity of the pin portion near P of the arm A Ac, the thickness of the Ad thick. However, it may be thicker one side only the thickness of the pin portion near P of the arm A, it may be thicker the thickness of only one side of the journal portion J vicinity of the arm portion A. Even in this case, the rigidity of the arm portion for the thickness of the pin portion P near or journal portion J vicinity of the side of the arm A is thick is ensured.
[0062]
　7A and 7B are schematic diagrams showing a rough arm portion shape of the forging burr before shaping processing in the second exemplary configuration has been removed of the present invention. Figure 7A is a front view as viewed from the crude pin side, FIG. 7B is a sectional view taken along the line VIIB-VIIB in FIG. 7A. 7A and 7B, illustrates a representative manner extract one of the coarse arm portion having no crude weight portion is omitted and the remaining crude arm.
[0063]
　Crude arm A before shaping machining 'is although not shown, as in the first configuration example above, the coarse journal portion J' of the side surface, the inner region of the side portions of the rough pin portion P 'vicinity has a surface shape that matches the final product shape after shaping process. Furthermore, crude pin portion P 'sides Aa near', the Ab ', like the first configuration example described above, first the excess thickness portion Aaa projecting from the respective outer peripheral, Aba is formed.
[0064]
　No coarse weight portion before shaping machining rough arm A ', as shown in FIGS. 7A and 7B, unlike the first configuration example above, the coarse pin portion P' of the side surfaces, rough journal part J 'both sides of the vicinity Ac', the inner region At of Ad ', with a surface shape that matches the final product shape after shaping process. Its surface shape roughness journal portion J 'sides Ac near', extends smoothly to a region Ad '. Thus, the coarse journal portion J 'sides Ac near', the thickness of the Ad 'is thinner than the thickness of the final product after shaping process.

claims.
　A plurality of journal portion as a rotational center, and a plurality of pin portions eccentric to the journal portion, the manufacturing process of forging the crank shaft having a plurality of crank arm portion connecting the pin portion and the journal portion, burrs an apparatus for producing a forged crankshaft subjected to processing in forging is removed,
　at least a portion of the crank arm portion of the plurality of crank arm portion of the forged crankshaft integrally counterweight unit a,
　wherein forging, the plurality of journal portions of the forged crankshaft, the plurality of pin portions, corresponding to each of the plurality of crank arm portion and said counterweight portion, a plurality of rough journal portion, a plurality of crude pin portion includes a plurality of coarse crank arm portion and the coarse counter weight portion,
　less of the plurality of coarse crank arm Ku and the rough crank arm portion of a part has a first excess thickness portion projecting from the outer periphery of the rough pin portion near the side, the forged crankshaft manufacturing apparatus,
　said first excess thickness portion a pair of molds with upper and lower subjected to processing to increase the thickness of the side of the rough pin vicinity of the rough crank arm portion is deformed,
　is accommodated in the opening portion of the mold, the rough crank arm portion and a first tool in contact with the surface except the region of the side of the rough pin vicinity among the rough journal portion of a surface,
　said mold and said first tool, said first tool a first guide portion for guiding from the retracted position to the contact position, respectively,
　at least one of the first of the upper and lower surfaces of the tool, said first guide portion is provided, forged crankshaft manufacturing apparatus.
[Claim 2]
　An apparatus for producing a forged crankshaft according to claim 1,
　wherein the forged crankshaft manufacturing apparatus further includes a first jig movable along the eccentric direction of the pin portion,
　said first jig , the first tool, said movably held to the first first sliding direction with a first guiding direction and angle along the guide portion,
　the first tool relative to the rough crank arm portion, the crude abutting said surface except the region of the side of the rough pin portion near the journal portion,
　the first tool is moved along the first guide direction with the movement of the first jig, forged crankshaft manufacturing apparatus.
[Claim 3]
　An apparatus for producing a forged crankshaft according to claim 1 or claim 2,
　all of the crank arm portion of the forged crankshaft has integrally the counterweight unit, forged crankshaft manufacturing apparatus.
[Claim 4]
　An apparatus for producing a forged crankshaft according to claim 1 or claim 2,
　wherein at least a portion of the crude crank arm portion of said coarse crank arm portion having no crude counterweight unit, the coarse further comprising a second excess thickness portion projecting from the outer peripheral side of the journal portion near
　the mold has no the crude counterweight portion by deforming the second excess thickness portion and the coarse crank arm portion It said processing further subjected to increasing the thickness of the side of the coarse journal vicinity,
　the apparatus for manufacturing the forged crankshaft,
　the crude that is housed in the opening portion of the mold, without the crude counterweight unit further comprising abutting the second tool to the surface except for the area of the side of the rough journal vicinity among the rough pin portion-side surface of the crank arm portion,
　said die and said second tool, A second guide portion for guiding the serial second tool from the retracted position to the contact position, respectively,
　in at least one of the upper and lower surfaces of said second tool, said second guide portion is provided, forged crankshaft of manufacturing equipment.
[Claim 5]
　An apparatus for producing a forged crankshaft according to any one of claims 1 to 4,
　wherein the mold is a mold for performing shaping processing to the forging material, forging the crank shaft of the manufacturing equipment.