Technical field
[0001]
　The present invention, drawing, stretch flangeability, bending, in the molding of a metal plate, such as stretch forming, and molding methods fracture does not occur, a molded article molded by the molding method.
Background technique
[0002]
　Usually, the molding of the metal plate, decreases as the strength of the metal plate is increased. Therefore, especially when molding high metal plate strength, the plastic deformation can not follow at the site to be molded, the internal stress is broken beyond the breaking strength.
[0003]
　Figure 1 illustrates aspects of a fracture at the shoulder portion of the punch in the drawing of the metal plate. The blank 1 of a metal plate, into the die block 2, while pressing the flange portion 1 of the blank 1 'in the blank holder 4, performs drawing by pushing a punch 3. Drawing the 'a breaking strength of the blank 1, the flange portion 1 of the blank 1' shoulder 3 of the punch 3 draw forming under the balance between the drawing force acting on progresses.
[0004]
　Then, the flange portion 1 'deformation resistance 6 of the shoulder portion 3 of the punch 3' when becomes equal to the breaking strength of the blank 1 in contact with the deformation of the flange portion 1 '(drawn into the die 2) is stopped and, on the other hand, deformation only at the site of the blank 1 in contact with the shoulder 3 of the punch 3 'is broken in progress.
[0005]
　To avoid breaking the drawing of the blank, it is important that the breaking strength of the portion contacting a shoulder portion of the punch is high, heretofore, a technique for preventing breakage of the blank during drawing several Proposed.
[0006]
　Patent Document 1, when the press-molding a blank, a portion where the plate thickness reduction of the blank is expected, a method for press-molding by providing a weld bead 2 or more has been proposed.
[0007]
　Patent Document 2, or 15% or more strength × thickness than the material of the central portion is low, or, better high-tensile steel plate of ductile than the material of more than 5% the heart is, other than the portion to be deep-drawn after product in, over the entire periphery of the diaphragm flange portion to impart wrinkle suppressing force during molding, press molding tailored blank having excellent deep drawability, which is welded with steel sheets have been proposed.
[0008]
　However, in either technique, the material becomes brittle at a welding heat input portion of the blank, the material of the blank so becomes nonuniform, it is difficult to completely avoid breakage of the blank during press molding.
CITATION
Patent Literature
[0009]
Patent Document 1: Laid-Open Publication No. 10-175024
Patent Document 2: JP Patent No. 4532709
Summary of the Invention
Problems that the Invention is to Solve
[0010]
　In general, as a method for preventing the breakage in the forming of the metal plate is mainly improved molding process, and can be considered a material improvement in the metal plate. For example, in the improvement of the aperture forming step, splitting method and the mold, an increase in the number of pressing steps is considered, in these methods, increase or molding cost, reduction in productivity is inevitable.
[0011]
　Patent Documents 1 and 2, as a material improvement in the high-strength steel sheet, a change in the material by partial quenching (reinforced) and is joining the heterogeneous material is disclosed. However, even these methods, likewise, increase or molding cost, reduction in productivity is inevitable.
[0012]
　The present invention, in the forming of the metal plate, the material of the metal plate, and, without changing the molding process, and an object thereof is metal plate is shaped so as not to break, and molding method for solving the problems, the and to provide a molded article molded by the molding method.
Means for Solving the Problems
[0013]
　The present inventors have intensively studied a technique for solving the above problems. As a result, the present inventors found that upon shaping of the metal plate, if joining the reinforcing material (Reinforcing Material) to the site in need required breaking strength, improved fracture strength of the above sites, that can prevent breakage heading was.
[0014]
　The present invention has been made based on the above findings, its gist the following.
[0015]
　(1) A method of forming a metal plate, prior to molding to bond the reinforcing member to a portion of the metal plate, then forming method of the metal plate, which comprises molding the metal plate.
[0016]
　(2) the reinforcing material, forming method of the metal plate of the (1), characterized in that the thickness of the metal plate in the molding is joined to the site to reduce.
[0017]
　(3) method of forming a metal plate (1) or (2) to the metal sheet tensile strength is characterized by a high strength steel sheet of more than 590 MPa.
[0018]
　(4) the said reinforcing material is characterized by a fiber-reinforced plastic (1) to any of the forming method of a metal plate (3).
[0019]
　(5) the direction of the fibers of the fiber-reinforced plastic, metal plate shaping method of the above (4) breaking strength of the metal plate, characterized in that it is joined along the required direction.
[0020]
　(6) any of the metal plate shaping method of the said reinforcing member being a high-strength steel foil (1) to (3).
[0021]
　(7) the (1) to (6) or a high strength steel plate molded article characterized by being squeezed molding in the method of the.
Effect of the invention
[0022]
　According to the present invention, in the molding of a metal plate, the material of the metal plate, and, without changing the molding process, increasing the breaking strength of the site necessary breaking strength, improved formability of a metal sheet, drawing it is possible to prevent the break in.
BRIEF DESCRIPTION OF THE DRAWINGS
[0023]
Is a diagram showing an aspect of a fracture at the shoulder portion of the punch in the drawing of FIG. 1 high-strength steel sheet.
In draw forming of FIG. 2 high-strength steel sheet, the site necessary breaking strength, showing aspects of preventing breakage by joining a sheet of fiber-reinforced plastic.
In [3] drawing of a high-strength steel sheet, the site necessary breaking strength, showing aspects bonding the fiber-reinforced plastic as a reinforcing material. (A) is a cyclic site necessary breaking strength, shows a mode of joining the annular fiber-reinforced plastic, (b) show a molded section of the molded article squeezed blank shown in (a).
In [4] drawing of a high-strength steel sheet, the site necessary breaking strength is a diagram illustrating another embodiment of joining the fiber-reinforced plastic as a reinforcing material. (A) is the annular portion of the double necessary breaking strength, shows an embodiment in which joined annular fiber-reinforced plastic, respectively, (b), the cross section of the molded article molded squeeze blank shown in (a) It is shown.
In FIG. 5 annular site necessary rupture strength is a diagram showing a manner of dividing to joining the patch of the annular fiber-reinforced plastic as a reinforcing material.
In [6] deep drawing, to be a fracture concern site is a diagram showing the position of the punch shoulder expected.
In [7] stretch flangeability is a diagram showing the position of the flange edge to be expected to be broken concerns site.
In [8] bending, it shows the position of the bending that is expected to be broken concerns site.
In [9] stretch forming, it shows the position of the punch protruding portion to be expected to be broken concerns site.
In the molding of FIG. 10 a metal plate having a complicated shape is difficult to predict the site necessary rupture strength is a diagram showing a flow for determining the position of joining the reinforcing material.
[11] of high-strength steel sheet, a diagram illustrating a method of joining sheets of fiber-reinforced plastic to the site in need rupture strength.
In drawing [Figure 12] a high-strength steel sheet, the site necessary breaking strength shows the case where the drawing without joining the sheet of fiber-reinforced plastic, the case where the drawing by joining a sheet of fiber-reinforced plastic it is a diagram. (A) is required site breaking strength, shows a case where the drawing without joining the sheet of fiber-reinforced plastic, (b), the required site rupture strength, and bonding a sheet of fiber-reinforced plastic It shows the case where the draw forming Te.
DESCRIPTION OF THE INVENTION
[0024]
　Method of forming a metal plate of the present invention is a molding method for molding a metal plate, the breaking strength must site (hereinafter referred to as "breaking concerned site"), in advance, characterized in that the drawing by joining a reinforcing material to.
[0025]
　Molded article of the present invention is characterized in that molded in the molding process of the present invention.
[0026]
　It is described with reference to the accompanying drawings forming method of the present invention.
[0027]
　2, as an example of the present invention, the drawing of the high-strength steel sheet, the site necessary breaking strength, indicating a manner to prevent rupture by joining a sheet of fiber-reinforced plastic.
[0028]
　The blank 1 of high strength steel, in die 2, while pressing the flange portion 1 of the blank 1 'in the blank holder 4, performs drawing by pushing a punch 3. Drawing proceeds under balance 'and breaking strength of the blank 1, the flange portion 1 of the blank 1' shoulder 3 of the punch 3 and the retraction force applied to.
[0029]
　Then, as described above, the flange portion 1 'deformation resistance 6 of the shoulder portion 3 of the punch 3' when becomes equal to the breaking strength of the blank 1 in contact with the deformation of the flange portion 1 '(to the die 2 drawn) is stopped, whereas, only deformed portion of the blank 1 in contact with the shoulder portion 3 'of the punch 3 is broken in progress (Fig. 1, reference).
[0030]
　On the other hand, in the draw-molding of high-strength steel sheet shown in FIG. 2, the portion 7 required breaking strength, in advance, bonded to draw forming a sheet 8 of a fiber reinforced plastic as a reinforcing material.
[0031]
　In the drawing the blank 1, the site where there is a concern broken during drawing, i.e., when bonding the sheet 8 of the fiber reinforced plastic parts 7 required breaking strength, breaking strength at the site 7 required breaking strength is improved during drawing, the blank 1 is not broken.
[0032]
　2, during the drawing of the high-strength steel, fiber reinforced plastic sheet 8, so that it can sufficiently exhibit the breaking strength improved function reliably joined to the site 7 required breaking strength, the fiber-reinforced plastic sheets 8, It shows a bonded manner so as to wrap the bottom of the drawing article. Manner of joining the reinforcing material to the site in need rupture strength is not limited to bonding the embodiment shown in FIG. 2, the extent to reliably bond the reinforcing material to the site in need rupture strength, can employ various bonding aspects . This will be described later shows another bonding aspect.
[0033]
　The molded article, in accordance with the shape of the molded article, separately molded carbon fiber reinforced plastics (CFRP, Carbon Fiber Reinforced Plastic) bonding the sheet or patch, to enhance the mechanical properties or functionality of the moldings or reinforcing techniques It is known (for example, the 2010 strategic foundation technology advancement support project report, "a study on the press-forming technology of CFRP- metal hybrid parts for automotive structural members", and, in 2014 fiscal plastic processing spring Lecture in published "basic Study on the effect of reinforcing the CFRP plate in impact bending deformation of the cylindrical state", see).
[0034]
　However, the molding method of the present invention has been made to the basic idea is to increase the formability of a portion integrally joined prior to molding the reinforcement material to be formed (blank), were joined the sheet or patch There, in this respect, the present invention forming method, after molding, to adhere the sheet or patch of fiber-reinforced plastic moldings, fundamentally different from the method of enhancing the mechanical properties or functionality of the molded article or the reinforcement it is intended.
[0035]
　In the molding of the blank 1, the site where there is a concern broken during molding, i.e., the breaking strength is to bond the fiber-reinforced plastic sheets required site, and increased fracture strength is at a site requiring breaking strength, during the molding , the blank is not broken is the novel finding by the present inventors have found, it is characteristic of the molding method of the present invention.
[0036]
　Figure 3 is the drawing of a high-strength steel sheet, the site necessary breaking strength, shows an embodiment in which joined the patch of the fiber-reinforced plastic. 3 (a) is a cyclic site necessary breaking strength, a mode to which bonding patches annular fiber-reinforced plastics, Fig. 3 (b) was molded squeeze blank shown in FIG. 3 (a) It shows a cross section of the molded article.
[0037]
　In the blank 1 shown in FIG. 3 (a), the site where there is a concern broken during drawing, i.e., comes into contact with the shoulder portion of the punch, so as to cover a portion of the required annular rupture strength, as a reinforcing material , an annular fiber-reinforced plastic sheet 8a is bonded.
[0038]
　As shown in FIG. 3 (a), in draw forming of high-strength steel sheet, a portion where there is concern broken during drawing, i.e., comes into contact with the shoulder portion of the punch, breaking strength and the necessary sites, before drawing the ability to identify, a sheet of fiber reinforced plastics wider than the width of the identified site, by joining so as to completely cover the identified site, to improve moldability by increasing the rupture strength at the site to can.
[0039]
　As shown in FIG. 3 (b), sites in the molded article 1a which draw forming the blank shown in FIG. 3 (a), there is a fear of the fracture formed by joining fiber reinforced plastic sheet 8a, during drawing, i.e. , it comes into contact with the shoulder portion of the punch, at the site requiring breaking strength, there is no rupture.
[0040]
　4, in draw forming of high-strength steel sheet, the site necessary breaking strength, shows another embodiment bonding the fiber-reinforced plastic patch. In FIG. 4 (a), a double annular site necessary breaking strength, shows a mode of joining the patches of the annular fiber-reinforced plastic, respectively, in FIG. 4 (b), the blank shown in FIG. 4 (a) the showing a diaphragm molded molded article of the cross-section.
[0041]
　In the blank 1 shown in FIG. 4 (a), the site where there is a concern broken during drawing, i.e., in contact with the shoulder portion of the punch, breaking strength is a double annular sites required to cover respectively, an annular fiber-reinforced plastic sheets 8b and 8c are joined.
[0042]
　As shown in FIG. 4 (a), in draw forming of high-strength steel sheet, a portion where there is concern broken during drawing, i.e., comes into contact with the shoulder portion of the punch, site necessary breaking strength is there exist a plurality of also, if it is possible to specify the position of the site, by joining the fiber-reinforced plastic sheets so as to completely cover the identified site, to improve moldability by increasing the rupture strength at multiple sites specified above can.
[0043]
　As shown in FIG. 4 (b), in the molded article 1b which draw forming the blank shown in FIG. 4 (a), were joined sheets 8b and 8c of the fiber-reinforced plastic, there is concern broken during drawing site, i.e., in contact with the shoulder portion of the punch, in a double annular site necessary breaking strength, there is no rupture.
[0044]
　In FIGS. 3 and 4, although the case of applying the aperture of the axisymmetric forming a circular blank, to the blank not limited to a circular blank, and drawing is the aperture of the axisymmetric molding but it is not limited.
[0045]
　According to the molding method of the present invention, since the improved breaking strength of the breaking strength is required site (broken concerns site) is, the degree of freedom of the shape of the blank, the degree of freedom in shaping aspects, and freedom of shape of molded article degree is greatly expanded.
[0046]
　In the molding process of the present invention, the site where there is a concern broken during draw forming of the blank, i.e., in contact with the shoulder portion of the punch, if it is possible to break tolerance to identify the site necessary, to cover the identified site by joining a reinforcing material so, it is possible to prevent breakage by increasing the fracture strength at the site specified above.
[0047]
　3 and 4 show the manner of joining the sheets of the annular fiber-reinforced plastic as a reinforcing material to the site in need rupture strength. The shape of the reinforcing member is not limited to a specific shape, specified rupture strength of parts required shape may be appropriately set according to the position or the like.
[0048]
　3 and 4, outside the site necessary breaking strength, but shows a mode of joining the sheets of the annular fiber-reinforced plastic, where joining the reinforcing material is limited to the outside of the site necessary breaking strength Sarezu, inner site necessary breaking strength, outer, and may be either on both sides of. Location of joining a reinforcing material, the shape of the site necessary breaking strength may be determined as appropriate depending on the position or the like.
[0049]
　Further, a reinforcing material, if the breaking strength is joined to the required site, may be joined appropriately divided and.
[0050]
　5, the annular section required breaking strength, indicating a manner joined by dividing the annular fiber-reinforced plastic is a reinforcement. In FIG. 5, and divided into four annular fiber-reinforced plastic, fiber reinforced plastic 8a 'are joined side by side annularly.
[0051]
　When splitting to joining reinforcement, dividing aspect, the identified fracture strength of sites required shape may be appropriately set according to the position or the like.
[0052]
　Has been described as an example draw forming a molding method of the present invention. Molding method of the present invention is not limited to the drawing, as shown in FIGS. 6-9 is also applicable in a variety of molding. Figure 6-9 shows a cutaway concerns sites in various molding. Figure 6 is deep drawing, FIG. 7 is stretch flangeability, 8 bending, FIG. 9 shows a bulging. With such a general molding, prediction of fracture concern site is relatively easy.
[0053]
　More specifically, if the deep drawing punch shoulder 61, the flange end 71 if stretch flangeability, site 81 bend if bending, if bulging, punch protruding portion 91 is broken concerns site . Therefore, before forming the metal plate, joining the reinforcing material so as to cover the position where this portion at the time of molding, may be performed shaping.
[0054]
　For molding of a metal plate having a complicated shape it is difficult to predict the site necessary rupture strength is, as shown in FIG. 10, CAE (computer aided engineering) by breaking concerns thickness is reduced in the case of not using the reinforcement predict site, by analyzing again CAE molding in the case of joining the reinforcing material to fracture concerns site may be determine the position of joining the reinforcing material.
[0055]
　Reinforcements during molding, as long as it can bear the stress rupture concerns site, regardless particular material. Considering the ease of use and strength, sheet or fiber reinforced plastic, it is preferable to use a high-strength steel foil. Fiber-reinforced plastic may be any plastic which is reinforced with fibers, it is not limited to the specific fibers and plastics. Suitable examples include carbon fiber reinforced plastics. The high-strength steel foil, steel foil tensile strength at room temperature is greater than or equal to 600MPa can be exemplified.
[0056]
　When using a fiber-reinforced plastic as a reinforcing material, the direction of the fibers of the fiber reinforced plastic, along the required direction breaking strength, specifically, it is preferable to bond to cross the cracks to be generated.
[0057]
　Reinforcement, because the site necessary breaking strength thereby improving the breakdown strength, it is necessary to required thickness is not limited to a particular thickness. The thickness of the reinforcing material, the material of the blank, drawing mode may be set as appropriate in consideration of the shape of the molded article.
[0058]
　Required site rupture strength is, the molded article obtained by molding a blank formed by joining reinforcement, depending on the application, may be used to remove the reinforcing member, also be used while joined to the reinforcing material good.
[0059]
　Therefore, the site necessary breaking strength, bonding strength when bonding the reinforcing material may be appropriately selected depending on the shaped article applications.
[0060]
　Method of joining a reinforcing material to the site in need rupture strength is not particularly limited. If the reinforcing material is a fiber-reinforced plastic, preferably used adhesive or resin. Type of adhesive or resin is not particularly limited, from the molded article, or removing the reinforcements, or, taking into account whether it may be selected adhesive appropriately. Reinforcement is a high strength steel foil, if it is not necessary to remove the reinforcing member from the molded article, it may be bonded by diffusion bonding.
[0061]
　Here, moldability is improved breaking proof stress will be described a mechanism for improved by joining a reinforcing material.
[0062]
　In general, when molding the diaphragm the blank in a die and a punch, breaking strength of abutting blank the shoulder of the punch: Pbreak can be calculated by the following formula (1) (plastic processing technology Series 13 "press drawing - step design and die design - "(corona), 23 pp., see).
　Pbreak = 2PaiRt 0 F {2 (r + 1) (r + 2) / 3 (2r + 1)} (n + 1) / 2 (n
　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　/ e) n · · ·
　　(1) R: radius of the punch
　　t 0 : thickness of the blank is
　　r: Lankford value
　　e: Napier number (the base of the natural
　　logarithm) F, N: Swift equation parameters of
[0063]
　Breaking concerns site of the blank (sites where there is concern broken during drawing), i.e., contact with the shoulder portion of the punch, breaking strength and the necessary sites, breaking strength of the blank when reinforced with a reinforcing material: P'break can be defined by the following formula (2).
　= Pbreak + P'break 2PaiRt frp TS frp　　　　　　　　　　　　　· · ·
　　(2) P'break: breaking strength abutting blank the shoulder of the punch
　　R: punch radius
　　t frp : reinforcement thickness
　　TS frp : tensile reinforcement Strength
[0064]
　As shown in the equation (2), the fracture concerns site of the blank, if the bonding sheets or patches of fiber-reinforced plastic as a reinforcing material, breaking strength after bonding: P'break is the blank breaking strength: since more than Pbreak, it can be expected to improve the moldability in the fracture concerned site. Thus, the molding process of the present invention can support even theoretically.
[0065]
　Molding method of the present invention is a metal plate as a workpiece, be effective regardless of the molding contents. In particular, there is a tendency that moldability is lowered, tensile strength is very effective in forming the above high strength steel sheet 590 MPa.
Example
[0066]
　Next, a description will be given of an embodiment of the present invention, conditions in examples are an example of conditions adopted for confirming the workability and effects of the present invention, the present invention is, in this single condition example the present invention is not limited. The present invention does not depart from the gist of the present invention, as long as they achieve the object of the present invention, it is capable of adopting various conditions.
[0067]
　(Example)
　As shown in FIG. 11, the thickness of 1.0 mm, on a blank of diameter 108 mm (dual phase steel) 112, thickness 0.7 mm, the adhesive sheet having a diameter of 58 mm (polypropylene resin sheet) 113 When a thickness of 0.23 mm, a carbon fiber reinforced plastic sheet 111 of diameter 58 mm, stacked in this order, in warm crimping machine 114, after heating for 1 minute at ° C. 180, 0.049 MPa (≒ 5Tonf / m 2 ) 1 minute pressurized by air cooling, were bonded carbon fiber reinforced plastic 111 to the blank 112.
[0068]
　The blank 112 formed by joining the carbon fiber reinforced plastic 111, and drawing using a punch and a die used in Comparative Example.
[0069]
　(Comparative Example)
　thickness 1.0 mm, blank diameter 108mm (dual phase steel) and drawing using the following punches and dies.
　Punch shoulder: R5 Punch diameter: 50mm
　die shoulder: R5 die diameter: 60 mm
　Blank holder pressure: 0.098 MPa (≒ 10Tonf / m 2 )
[0070]
　The results, shown in Figure 12. (A) is a site that requires breaking strength, a comparative example in which drawing without joining the sheet of fiber-reinforced plastic, (b) is a site that requires breaking strength, bonding a sheet of fiber-reinforced plastic to the result of the drawing and embodiments.
Industrial Applicability
[0071]
　According to the present invention, in the molding of a metal plate, the material of the metal plate, and, without changing the molding process, increasing the breaking strength of the site necessary breaking strength, improved formability of a metal sheet, during the molding it is possible to prevent the break. The present invention is a metal plate as a workpiece, be effective regardless of the molding contents. In particular, there is a tendency that moldability is lowered, drawing of high-strength steel sheet, stretch forming, stretch flangeability, the bending very effective. The present invention has high applicability in metal products manufacturing industry.
DESCRIPTION OF SYMBOLS
[0072]
　1 blank
　1 'flange portion
　1a, 1b molded article
　2 die
　3 punches
　3' shoulders
　4 blank holder
　5 at break
　6 deformation resistance
　7 breaking strength is required site
　of 8 fiber-reinforced plastic sheets
　8a, 8a 'reinforcement of the fiber reinforced plastic wood
　8b, 8c fibers reinforced plastic stiffener
　61 punch shoulder
　71 flange end
　81 bending point
　91 punch protruding portion
　111 carbon fiber reinforced plastic sheets
　112 blank
　113 adhesive sheet
　114 warm crimping machine

The scope of the claims
[Claim 1]
　A method of forming a metal plate, prior to molding to bond the reinforcing member to a portion of the metal plate, then forming method of the metal plate, which comprises molding the metal plate.
[Claim 2]
　Said reinforcement, metal plate shaping method according to claim 1, characterized in that the thickness of the metal plate in the molding is joined to the site to reduce.
[Claim 3]
　Method of forming a metal sheet according to claim 1 or 2, characterized in that said metal plate is a tensile strength of high strength steel sheet of more than 590 MPa.
[Claim 4]
　Method of forming a metal sheet according to any one of claims 1 to 3, characterized in that said reinforcing material is a fiber-reinforced plastic.
[Claim 5]
　The direction of the fibers of the fiber reinforced plastic, metal plate shaping method according to claim 4, characterized in that the breaking strength of the metal plate is joined along the required direction.
[Claim 6]
　Method of forming a metal sheet according to any one of claims 1 to 3, characterized in that said reinforcing material is a high strength steel foil.
[Claim 7]
　Molded article, characterized in that draw forming by molding method of the high strength steel sheet according to any one of claims 1-6.