JP2005279688A - Press-forming method and press-forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a press-forming apparatus capable of suppressing cracks or breakage at a joining end face of a blank which is joined by butting end faces of dissimilar plates to each other. <P>SOLUTION: The press-forming apparatus has a forming means to press-form a blank 110 formed by butt-joining end faces of dissimilar plates to each other and a restricting means 280 to restrict joining end faces 142 of the blank 110 during the press-forming by the forming means. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a press molding method and a press molding apparatus.

  In recent years, a blank material formed by abutting and joining end surfaces of different kinds of plate materials having different thicknesses and strengths has been used as a press material (for example, see Patent Documents 1 to 3).

For example, since it is possible to select an optimal plate thickness and strength for each part, the press material can reduce the number of parts and reduce the weight.
Japanese Patent Laid-Open No. 10-180470 Japanese Patent Laid-Open No. 11-104750 JP 2003-19516 A

  However, dissimilar plate materials are obtained by blanking the material plates. To prevent burrs, the corners have a gentle shape and are joined by welding, so the joints harden. ing.

  That is, the joint end surface of the dissimilar plate material is V-shaped and has low elongation ductility. Therefore, when press molding is performed, stress is concentrated and cracks and breaks are likely to occur. Therefore, there is a problem that the material yield is deteriorated and the cost is increased.

  The present invention has been made to solve the problems associated with the above-described prior art, and press molding that can suppress cracks and breaks in the joining end surface of a blank material formed by abutting and joining the end surfaces of different kinds of plate materials. It is an object to provide a method and a press molding apparatus.

In order to achieve the above object, the invention described in claim 1
The invention according to claim 9 for achieving the above object is a press molding method characterized by constraining a joining end surface of a blank material formed by abutting and joining end surfaces of different kinds of plate materials, and press molding.
Forming means for press-molding a blank material formed by abutting and joining the end surfaces of different kinds of plate materials,
In press forming by the forming means, there is provided a press forming apparatus comprising a restraining means for restraining the joining end face of the blank material.

  The present invention configured as described above has the following effects.

  According to the first aspect of the present invention, the joint end face of the blank material formed by abutting and joining the end faces of the dissimilar plate materials concentrates stress during press molding, but is restrained, so that cracks and fractures occur. Occurrence is suppressed. That is, the press molding method which can suppress the crack and fracture | rupture in the joining end surface of the blank material formed by abutting and joining the end surface of a dissimilar board | plate material can be provided.

  According to the ninth aspect of the present invention, stress is concentrated on the joining end face of the blank material formed by abutting and joining the end faces of the dissimilar plate materials at the time of press forming by the forming means. When restraining, it is possible to suppress the occurrence of cracks and breaks. That is, the press molding apparatus which can suppress the crack and fracture | rupture in the joining end surface of the blank material formed by abutting and joining the end surface of a dissimilar board | plate material can be provided.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is a perspective view for explaining a press-formed product according to an embodiment of the present invention.

  The press-formed product according to the present embodiment is an automobile suspension component 10 used to connect an axle component and a vehicle body, and is formed from, for example, an aluminum alloy or steel.

  The suspension component 10 includes side members 20 and 25 and cross members 30 and 35. The side members 20, 25 have bent portions 21, 26 on the inner periphery of the end portions, and the end surfaces of the bent portions 21, 26 are connected to the end surface of the cross members 30, 35. Therefore, the suspension component 10 has a closed shape having the space S inside.

  FIG. 2 is a perspective view for explaining a press material according to the embodiment of the present invention.

  The press material according to the present embodiment is a tailored blank material 110 formed by abutting and joining the end surfaces of different kinds of plate materials, and the suspension component 10 is formed by press forming. The tailored blank material 110 is preferable in that, for example, an optimum plate thickness or material and strength can be selected for each part, and the number of parts can be reduced and the weight can be reduced.

  Tailored blank material 110 according to the present embodiment is a differential thickness tailored, thick plate portions 120 and 125 made of a plate material having a large plate thickness, thin plate portions 130 and 135 made of a plate material having a small plate thickness, and a thick plate portion. It has a joint portion 140 that connects 120, 125 and the thin plate portions 130, 135, and has a closed shape having a space S inside.

  The thick plate portions 120 and 125 and the thin plate portions 130 and 135 constitute the side members 20 and 25 and the cross members 30 and 35, respectively, after press molding. Inner peripheries of the end portions 121 and 126 of the thick plate portions 120 and 125 have bent portions 122 and 127, respectively. The bent portions 122 and 127 constitute the bent portions 21 and 26 of the side members 20 and 25 after press molding.

  Next, a method for forming a tailored blank material will be described. FIG. 3 is a conceptual diagram for explaining blanking of dissimilar plate materials constituting the tailored blank material (press material). FIG. FIG. 5 is a cross-sectional view for explaining the joining of different kinds of plate materials following FIG. 4.

  The plate materials 220 and 225 constituting the thick plate portions 120 and 125 and the plate materials 230 and 235 constituting the thin plate portions 130 and 135 are formed from coil materials having different plate thicknesses by blanking by the punching device 210, for example.

  Plate members 220, 225, 230, and 235 obtained from the coil material are input (arranged) into the jig base 260. Then, the end surfaces 221, 226, 231, and 236 are abutted by positioning in the cross direction CD and the side direction SD using the positioning pins 265 to 267, and a closed shape having a space S inside is obtained. The cross direction CD is a positioning direction of the plate members 230 and 235 that constitute the cross members 30 and 35. The side direction SD is a positioning direction of the plate members 220 and 225 that constitute the side members 20 and 25.

  For positioning in the cross direction CD, the movable positioning pin 266 is driven (moved), and the plate members 230 and 235 are brought into contact with the fixed positioning pin 265. In the positioning in the side direction SD, the movable positioning pin 267 is driven to bring the plate materials 220 and 225 into contact with the plate materials 230 and 235 positioned by the positioning pins 265 and 266.

  The positioned plate members 220, 225, 230, and 235 are fixed by the clamp means 270. The clamping means 270 is disposed along the abutting surface 240 of the end surfaces 221, 226, 231, 236, and fixes the abutting surface 240 by pressing the vicinity of the abutting surface 240 against the jig base 260. When positioning the plate members 220, 225, 230, and 235, it is preferable to pre-clamp the end surfaces 221, 226, 231, and 236 to limit the movable range, thereby suppressing the butt failure.

  In the present embodiment, plasma arc type plasma spraying is applied to the joining of the butt surfaces 240. Plasma spraying is preferable because it has good directivity and deep penetration and is suitable for press forming after welding. However, for example, thermal spraying such as laser welding or electron beam welding or other joining methods can be applied.

  As shown in FIG. 5, the plasma spraying apparatus has a torch 250 for ejecting a plasma arc. The torch 250 includes a plasma gas passage, a welding gas passage, and an electrode (cathode). The plasma gas is, for example, argon. The sealing gas is, for example, a mixed gas of argon and hydrogen.

  The jig base 260 that is in contact with the plate members (materials to be welded) 220, 225, 230, and 235 fixed by the clamp means 270 functions as an electrode (anode) that faces the electrode of the torch 250. Therefore, the torch 250 can eject a plasma arc toward the butting surfaces 240 of the plate materials (materials to be welded) 220, 225, 230, and 235.

  The jig base 260 has a groove 255 at a portion corresponding to the butting surface 240. The groove 255 is used to prevent the portion heated by the plasma arc or the weld bead from being welded to the jig base 260 and to distribute the sealing gas for the welded portion.

  Therefore, the torch 250 is disposed above one end (starting point) of the butting surface 240, and a plasma arc is ejected from the torch 250 toward the butting surface 240 while the other end (end point) of the butting surface 240 is reached. ), It is possible to weld over the entire length of the butt surface 240.

  The tailored blank 110 is formed by performing the above welding on the four butted surfaces 240. Accordingly, the plate members 220 and 225, the plate members 230 and 235, and the butting surface 240 constitute the thick plate portions 120 and 125, the thin plate portions 130 and 135, and the joint portion 140, respectively.

  FIG. 6 is a plan view for explaining the restraining means of the press molding apparatus according to the embodiment of the present invention, FIG. 7 is an enlarged detailed view of FIG. 6, and FIG. 8 is a press according to the embodiment of the present invention. Sectional drawing for demonstrating the shaping | molding means of a shaping | molding apparatus, FIG. 9 is a top view for demonstrating the removal of the level | step-difference part of the press raw material which concerns on embodiment of this invention.

  The press molding apparatus according to the embodiment of the present invention includes a restraining means 280 for restraining the joining end surface 142 of the tailored blank material 110 and a molding means 290 for press molding the tailored blank material 110.

  The joining end surface 142 is located in the extending portion 115 where the stretch flange molding is performed inside the tailored blank material 110, and stress is concentrated during the press molding by the molding unit 290. However, by restraining by the restraining means 280, it is possible to suppress the occurrence of cracks and breaks. If necessary, the joint end surface 147 located outside the tailored blank material 110 can be similarly restrained.

  In the present embodiment, the joining end surface 142 is located at the stepped portion 143 whose end surface protrudes in the direction extending from the joining end surface 142, and the restraining means 280 restrains the stepped portion 143. More specifically, the restraining means 280 has a forming nest (male member) 282 corresponding to the step portion 143. The forming nest 282 is provided so as to be able to approach and separate from the joint end surface 142, and the stepped portion 143 can be easily restrained by the opening 283 of the forming nest 282.

  The step 143 is preferably formed when blanking the coil material from the viewpoint of productivity (see FIG. 3). In this case, the stepped portion 143 can be used for positioning when the blanked plate members 220, 225, 230, 235 are arranged on the jig base 260 for welding (see FIG. 4).

  The molding means 290 includes a first molding die 291 having a recess 292 and a second molding die 296 that is disposed relative to the first molding die 291. The recess 292 is disposed at a position facing the weld bead 141 formed in the joint 140 of the tailored blank material 110. The recess 292 is a mold relief having a shape larger than that of the weld bead, and has a size equal to or greater than the plate thickness, for example.

  Therefore, the concave portion 292 can maintain the weld bead 141 in a non-contact state during press molding, and can prevent the weld bead 141 from being pressed and cracked by the first molding die 291. .

  The second mold 296 has a pair of convex portions 297 that are disposed at positions facing the adjacent portions of the concave portion 292. The convex portion 297 can suppress the material flow by pressing the adjacent portion of the weld bead 141 against the adjacent portion of the concave portion 292 of the first mold 291 during press molding. Therefore, for example, the generation of wrinkles can be suppressed.

  It is preferable to set the cavity surface opposite to the weld bead 141 and its adjacent part so as to have a small curvature and a large curvature radius. In this case, a minute (fine) crack is generated in the weld bead 141, and the appearance of rough skin is suppressed.

  In addition, since the joining end surface 142 is located at one of the starting point or the ending point of welding, the joining end surface 142 and its vicinity are likely to cause poor welding such as perforation or spatter, and the welding quality is unstable. The step portion 143 includes the joint end surface 142 and the vicinity thereof.

  Therefore, it is possible to improve the welding quality by removing the stepped portion 143 after press forming (see FIG. 9). In addition, regarding the other joint end surface 147, it is possible to further improve the welding quality by forming a stepped portion that is removed after press molding.

  As described above, the present embodiment can provide a press molding apparatus that can suppress cracks and breaks in the joining end surface of the blank material formed by abutting and joining the end surfaces of different kinds of plate materials.

  The formation of the stepped portion 143 and the arrangement of the forming nest 282 can be appropriately omitted depending on the press forming conditions. Furthermore, without forming the stepped portion 143, it is possible to constrain the joining end surface 142 by using, for example, a protrusion or a recessed portion located in the vicinity of the joining end surface 142.

  Next, a press forming method using the press forming apparatus according to the embodiment of the present invention will be described.

  First, the tailored blank material 110 is placed on the first mold 291. At this time, the weld bead 141 formed on the joint 140 of the tailored blank 110 is positioned in the recess 292 of the first mold 291.

  The forming nest 282 of the restraining means 280 is driven so as to be close to the tailored blank member 110, and the step 143 of the tailored blank member 110 is restrained by the opening 283 of the forming nest 282. This fixes (restrains) the joining end surface 142 located substantially at the center of the stepped portion 143.

  The second mold 296 is driven so as to approach the first mold 291, and press molding is performed on the tailored blank material 110 loaded on the first mold 291. At this time, the convex portion 297 of the second mold 296 presses the adjacent portion of the weld bead 141 against the adjacent portion of the concave portion 292 of the first mold 291 to suppress the material flow. Therefore, for example, the generation of wrinkles can be suppressed.

  Although stress is concentrated on the joining end surface 142 of the tailored blank 110, the stepped portion 143 including the joining end surface 142 and the vicinity thereof is restrained by the forming nest 282 of the restraining means 280. Occurrence is suppressed.

  Since the concave portion 292 of the first mold 291 maintains the weld bead 141 of the tailored blank material 110 in a non-contact state, the weld bead 141 is prevented from being pressed by the first mold 291 and cracking.

  Thereafter, the stepped portion 143 is removed from the press-formed product. Since the stepped portion 143 includes a portion where the welding quality is unstable (joint end surface 142 and its vicinity), the press-formed product from which the stepped portion 143 has been removed has good welding quality.

  As described above, the present embodiment can provide a press molding method capable of suppressing cracks and breaks in the joining end surface of the blank material formed by abutting and joining the end surfaces of different kinds of plate materials.

  FIG. 10 is a perspective view for explaining a modified example of the press material according to the embodiment of the present invention, and FIG. 11 is a plan view for explaining the deformed portion shown in FIG.

  In this modification, the deformed portion 150 that deforms in the direction in which the peripheral length extends is formed before press forming for forming a bent portion on the inner periphery of the end portion in a later step. The deformed portion 150 is disposed in the thin plate portions 130 and 135 and is located in the vicinity of the joint portion 140. The deformed portion 150 is deformed at the time of press forming in a subsequent process, and its peripheral length is extended to buffer the extension of the extending portion 115. Therefore, during press molding, in addition to restraining the joint end surface 142 by the restraining means 280 (constraining the stepped portion 143 by the molding nest 282), the elongation of the stretched portion 115 is buffered, so that the occurrence of cracks and breakage is further increased. It is suppressed.

  In this modified example, the deformed portion 150 is formed of a concave portion that deforms in the direction in which the circumferential length extends, has a semi-conical shape in which the cross section has an arc shape, and the width and depth are gradually reduced and has a curvature. ing.

  The deformed portion 150 can be formed, for example, by performing preliminary press molding (second press molding) different from the press molding (final press molding). When pre-press forming is performed on the plate materials 220, 225, 230, and 235 before joining (immediately after blanking), there is a possibility that the end face may be deformed, and the welding quality when the tailored blank material 110 is formed by butt welding. Reduce. Therefore, pre-press molding is preferable after welding and before final press molding. However, if necessary, preliminary press molding can be performed before welding.

  FIG. 12 is a cross-sectional view for explaining a method for forming the deformed portion shown in FIG.

  The press forming apparatus 160 related to the pre-press forming includes a punch (male member) 161, a holder 163 for attaching and holding the punch 161, a die (female member) 164, and a forming nest 166.

  The punch 161 has a protrusion 162 corresponding to the concave shape of the deformed portion 150 of the tailored blank 110 and is disposed above the deformed portion 150. The die 164 has a deformed portion forming recess 165 that substantially matches the shape of the recessed portion of the deformed portion 150, and is disposed below the deformed portion 150. The forming nest 166 is disposed so as to be able to come into contact with the joint end surface of the tailored blank material 110 and the step portion including the vicinity thereof.

  Therefore, by driving the punch 161 held by the holder 163, the portion of the tailored blank material 110 facing the deformed portion forming recess 165 of the die 164 is pressed by the protruding portion 162 of the punch 161. The pressed portion of the tailored blank material 110 is deformed into a shape corresponding to the shape of the inner surface of the deformed portion forming recess 165 of the die 164 to form the deformed portion 150.

  At this time, the stepped portion of the tailored blank material 110 is fixed by the forming nest 166. As a result, stress is generated in the direction in which a crack is generated on the joint end surface of the tailored blank material 110 by the preliminary press molding, but the crack is surely suppressed.

  As described above, the press molding apparatus 160 can form the deformed portion 150 of the tailored blank material 110. If necessary, the press molding device 160 related to the preliminary press molding and the press molding device related to the final press molding can be integrated.

  In addition, since the outer periphery of the tailored blank 110 does not become a stretch flange during final press molding, there is a risk of wrinkling rather than lacking, and it is necessary to form a deformed portion 150 that deforms in the direction in which the peripheral length extends. There is no. On the other hand, in the part where the extent of stretch flange molding is large, the meat flows in from the surroundings, so the formation of the deformed part 150 is not effective. Therefore, it is preferable that the deformed portion 150 is formed at or around the extending portion located on the inner periphery of the tailored blank material 110.

  The present invention is not limited to the above-described embodiment, and various modifications can be made within the scope of the claims.

  For example, the press-formed product is not limited to automobile suspension parts, but can be applied to other structural members.

  The deformed portion is not limited to the concave portion as long as it has a shape that deforms in the direction in which the circumferential length extends during press molding, and may be configured by another shape, for example, a notch. In this case, it is preferable to make the notch part into a shape having a curvature and reliably suppress the occurrence of cracks due to stress concentration in the notch part during press molding.

It is a perspective view for demonstrating the press-formed product which concerns on embodiment of this invention. It is a perspective view for demonstrating the press raw material which concerns on embodiment of this invention. It is a conceptual diagram for demonstrating the formation method of the press raw material of FIG. 2, and has shown the blanking of the dissimilar board | plate material which comprises a press raw material. It is a top view for demonstrating positioning and fixation of a dissimilar board material following FIG. FIG. 5 is a cross-sectional view for explaining the joining of different kinds of plate materials following FIG. 4. It is a top view for demonstrating the restraint means of the press molding apparatus which concerns on embodiment of this invention. FIG. 7 is an enlarged detail view of FIG. 6. It is sectional drawing for demonstrating the shaping | molding means of the press molding apparatus which concerns on embodiment of this invention. It is a top view for demonstrating the removal of the level | step-difference part of the press raw material which concerns on embodiment of this invention. It is sectional drawing for demonstrating the modification of the press raw material which concerns on embodiment of this invention. It is a top view for demonstrating the unusual shape site | part shown by FIG. It is sectional drawing for demonstrating the formation method of the deformed site | part shown by FIG.

Explanation of symbols

10. Suspension parts,
20, 25 ... side members,
21, 26 .. bent part,
30, 35 ... cross member,
110 .. Tailored blank material,
115 .. extension part,
120, 125 ... Thick plate part,
121, 126 .. end,
122, 127 .. bent part,
130, 135 ... thin plate,
140 .. Joint part,
141..Welding bead,
142, 147 .. Join end face,
143 .. Stepped part,
150 ...
160..Press molding equipment,
161 ... Punch,
162 .. Protruding part,
163 .. Holder
164 ・ Die,
165 .. Recessed part forming concave part,
166 .. Molded nest,
210 .. Punching device,
220, 225, 230, 235, plate material,
221, 226, 231, 236 .. end face,
240 .... Butting surface 250 ... Torch,
255 ・ ・ Groove,
260 .. Jig base
265 to 267 .. locating pins,
270 .. Clamp,
280 ... Restraining means,
282 ... Molded nest,
283 .. opening,
290 .. Molding means
291 .. First mold,
292 .. recess,
296 .. Second mold,
297 .. Convex part,
S. ・ Space,
CD-cross direction,
SD side direction.

Claims (12)

  A press molding method characterized in that press molding is performed by constraining a joining end surface of a blank material formed by abutting and joining end surfaces of different kinds of plate materials.   2. The press molding according to claim 1, wherein the joining end surface is located at a stepped portion having an end surface projecting in a direction extending from the joining end surface of the blank material, and the projecting stepped portion is constrained. Method.   The press forming method according to claim 2, wherein the step portion is formed before the joining, and is used for positioning when the joining is performed.   The press molding method according to claim 2, wherein the stepped portion is removed after press molding.   The press forming method according to claim 1, wherein the joining is welding.   The press molding method according to claim 5, wherein the welding is plasma welding. The molding means for press molding includes a first molding die having a recess and a second molding die disposed relative to the first molding die, and the recess is formed at a joint portion of the blank material. Disposed at a position opposite to the weld bead to be formed, having a shape larger than the shape of the weld bead,
The press molding method according to claim 5 or 6, wherein the weld bead is positioned in the concave portion and maintained in a non-contact state during press molding. The second mold has a pair of convex portions arranged at positions facing the adjacent portions of the concave portions,
In press molding, the adjacent portion of the weld bead is pressed against the adjacent portion of the concave portion of the first mold by the convex portion of the second mold, and the material flow is suppressed. The press molding method according to claim 7. Forming means for press-molding a blank material formed by abutting and joining the end surfaces of different kinds of plate materials,
A press forming apparatus, comprising: a restraining means for restraining a joining end face of the blank material during press forming by the forming means. The joining end surface is located at a stepped portion where the end surface protrudes in a direction extending from the joining end surface of the blank material,
The press forming apparatus according to claim 9, wherein the restraining means restrains the protruding stepped portion. The joint is welding;
The forming means includes a first forming die having a recess and a second forming die disposed relative to the first forming die, and the recess is a weld formed at a joint portion of the blank material. The press molding apparatus according to claim 10 or 10, wherein the press molding apparatus is disposed at a position opposite to the bead and has a shape larger than that of the weld bead.   The press molding apparatus according to claim 11, wherein the second mold has a pair of convex portions arranged at positions facing the adjacent portions of the concave portions.

Images