Positioning structure, workpiece manufacturing method, and welding method

Abstract

To provide a positioning structure that can perform positioning of a work-piece without using a jig, and reduce time required in work for positioning the work-piece.SOLUTION: A positioning structure (GK) comprises a positioning convex part Wc formed to protrude from an end face W1a of a first work-piece W1 of a sheet metal, and a positioning concave part Wd formed so that the positioning convex part Wc is buried in and engaged with a surface of a second work-piece W2. The positioning convex part Wc is made to engage with the positioning concave part Wd, so that the end face W1a of the first work-piece W1 contacts a surface W2b of the second work-piece W2 and the first work-piece is positioned in an attitude which is orthogonal to the second work-piece W2.SELECTED DRAWING: Figure 10B

Description

[Technical field]

[0001] The present invention relates to a positioning structure, a workpiece manufacturing method, and a welding method. [Background technology]

[0002] A method for welding corner joints is described in Patent Document 1. The welding method described in Patent Document 1 involves using a jig to position and hold one workpiece so that the end face of the other workpiece overlaps the surface near the end of the other workpiece in a butted state, and then irradiating the butted area with a laser beam to perform butt welding. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2018-187665 A Summary of the Invention [Problem to be solved by the invention]

[0004] The welding method described in Patent Document 1 requires a jig according to the shape of the workpiece, etc., so there is room for reducing the cost of the jig and the time it takes to set up the jig. [Means for solving the problem]

[0005] A first aspect of the present invention is a method for manufacturing a workpiece having a first workpiece, the first workpiece being provided with a positioning protrusion formed by protruding from an end face of the first workpiece, and a second workpiece being provided with a positioning protrusion formed by protruding from an end face of the first workpiece. The first work and a positioning recess formed so that the positioning protrusion is embedded and engages at a position shifted by the protruding height from the surface, and by engaging the positioning protrusion with the positioning recess, the first work is positioned in a posture perpendicular to the second work by having its end face abut against the surface of the second work.

[0006] A second aspect of the present invention is a method for manufacturing a workpiece, in which a positioning protrusion of a first workpiece is engaged with a positioning recess formed in a second workpiece to position the first workpiece in an orthogonal orientation relative to the second workpiece, and the positioning protrusion is engaged with the first workpiece of sheet metal. Contour from End Face Thickness Full direction in a chamfered portion is formed on a tip edge of a punch that moves in a thickness direction of the first workpiece, and the punch is moved in the thickness direction at a position where it interferes with the protrusion, and the protrusion is plastically deformed to protrude from a part of the end face. In the plastic deformation, the protrusion is plastically flowed into a gap between the upper surface of the die side member with which the tip surface of the punch abuts and the chamfered portion, forming a tapered shape having an inclined surface corresponding to the chamfered portion and a bottom surface corresponding to the upper surface. This is a method for manufacturing a workpiece to be formed.

[0007] In addition, a third aspect of the present invention is a first workpiece of sheet metal. Contour from End Face Thickness Full direction in a punch moving in the thickness direction of the first workpiece at a position where it interferes with the protrusion, plastically deforming the protrusion so that it protrudes from a part of the end face to form a positioning convexity; a positioning recess into which the positioning convexity is embedded and engages is formed on the surface of a second workpiece against which the end face of the first workpiece is abutted, at a position shifted by the height of the positioning convexity from a predetermined position against which the first workpiece is abutted; the positioning convexity is engaged with the positioning recess to position the first workpiece at the predetermined position of the second workpiece and abut them together; and the abutted portion is welded to join the first workpiece and the second workpiece. Effect of the Invention

[0008] According to one aspect of the present invention, it is possible to position workpieces for butt welding without using a jig, thereby reducing the cost of the jig and the time required to set up the jig. [Brief description of the drawings]

[0009] [Figure 1A] FIG. 1A is a schematic cross-sectional view showing an example of the configuration of a thin plate convex portion forming die KD1 for forming a positioning convex portion WcA according to the first embodiment. [Figure 1B] FIG. 1B is a partially enlarged view of FIG. 1A. [Figure 2A] 13 is a schematic cross-sectional view showing an example of the configuration of a thick plate convex portion forming die KD2 for forming a positioning convex portion WcB according to one aspect of this embodiment. FIG. [Figure 2B] FIG. 2B is a partially enlarged view of FIG. 2A. [Figure 3A] FIG. 3A is a first schematic plan view for explaining a first embodiment of a method for forming the positioning convex portion Wc. [Figure 3B] FIG. 3B is a second schematic plan view for explaining the first embodiment. [Figure 3C] FIG. 3C is a third schematic plan view for explaining the first embodiment. [Figure 3D] FIG. 3D is a fourth schematic plan view for explaining the first embodiment. [Figure 4A] FIG. 4A is a first schematic plan view for explaining a second embodiment of the method for forming the positioning convex portion Wc. [Figure 4B] FIG. 4B is a second schematic plan view for explaining the second embodiment. [Figure 4C] FIG. 4C is a third schematic plan view for explaining the second embodiment. [Figure 4D] FIG. 4D is a fourth schematic plan view for explaining the second embodiment. [Figure 5A] FIG. 5A is a schematic cross-sectional view showing a configuration example of a recess forming die KD3 for forming the positioning recess Wd according to one aspect of this embodiment. [Figure 5B] FIG. 5B is a partially enlarged view of FIG. 5A. [Figure 5C] FIG. 5C is a perspective view of the molding portion 32P of the recess forming die KD3 as viewed obliquely from above and front left. [Figure 5D] FIG. 5D is a schematic cross-sectional view showing an example of the configuration of a recess forming die KD3A which is a modified example of the recess forming die KD3. [Figure 6A] FIG. 6A is a top view of the positioning recess Wd. [Figure 6B]FIG. 6B is a cross-sectional view taken along the line AA in FIG. 6A. [Figure 7A] FIG. 7A is a schematic plan view showing a first step of a first example of a method for forming the positioning recess Wd according to one aspect of this embodiment. [Figure 7B] FIG. 7B is a schematic plan view showing a second step of the first example of the method for forming the positioning recess Wd according to one aspect of this embodiment. [Figure 7C] FIG. 7C is a schematic plan view showing a third step of the first example of the method for forming the positioning recess Wd according to one aspect of this embodiment. [Figure 8A] FIG. 8A is a schematic plan view showing a first step of a second molding method example of the positioning recess Wd according to one aspect of this embodiment. [Figure 8B] FIG. 8B is a schematic plan view showing a second step of the second molding method of the positioning recess Wd according to one aspect of this embodiment. [Figure 8C] FIG. 8C is a schematic plan view showing a third step of the example of the second molding method for the positioning recess Wd according to one aspect of this embodiment. [Figure 9A] FIG. 9A is a top view for explaining the positioning structure GK for the thick plate workpiece Wb. [Figure 9B] FIG. 9B is a cross-sectional view taken along the line BB in FIG. 9A. [Figure 10A] FIG. 10A is a top view for explaining the positioning structure GK for the thin plate workpiece Wa. [Figure 10B] FIG. 10B is a cross-sectional view taken along the line CC in FIG. 10A. [Figure 10C] FIG. 10C is a perspective view for explaining the positioning structure GK for the thin plate workpiece Wa. [Figure 11A] FIG. 11A is a partial cross-sectional view for explaining the positioning structure GK2. [Figure 11B] FIG. 11B is a cross-sectional view for explaining a first mode of the positioning structure GK2. [Figure 11C] FIG. 11C is a cross-sectional view for explaining a second mode of the positioning structure GK2. [Figure 12A] FIG. 12A is a schematic side view showing a one-way pull welding mode that can be supported by the positioning structure GK according to one aspect of this embodiment. [Figure 12B] FIG. 12B is a schematic side view showing a half-pull welding mode that can be handled by the positioning structure GK according to one aspect of this embodiment. [Figure 12C] FIG. 12C is a schematic cross-sectional view showing an example of a welding mode in the positioning structure GK2. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] An aspect of an embodiment will now be described with reference to the drawings.

[0011] In the drawings, the same parts are given the same reference numerals and the explanation is omitted. For convenience of explanation, the up, down, left, right, front and back directions are defined by arrows in each drawing. In the positioning structure GK according to one aspect of this embodiment, a positioning convex portion is formed on one of two sheet metal workpieces (hereinafter, workpieces) to be joined in an orthogonal posture, and a positioning concave portion is formed on the other, and the two workpieces are positioned in an orthogonal posture by the concave-convex engagement between the positioning convex portion and the positioning concave portion.

[0012] The positioning convex portion and the positioning concave portion are formed by a convex portion forming die and a concave portion forming die, respectively. First, the thin plate convex portion forming die KD1 and the thick plate convex portion forming die KD2 for forming the positioning convex portion will be described with reference to Figs. 1A to 2B. The workpiece W is a metal plate, for example, an iron plate or an aluminum plate. The iron plate is, for example, a cold rolled steel plate (SPC) or a stainless steel plate (SUS). In the iron plate workpiece W, a plate with a thickness t of less than 1.6 mm is called a thin plate workpiece Wa, and a plate with a thickness t of 1.6 mm or more is called a thick plate workpiece Wb. The thin plate convex portion forming die KD1 is used for processing the thin plate workpiece Wa, and the thick plate convex portion forming die KD2 is used for processing the thick plate workpiece Wb.

[0013] (Configuration of KD1 thin plate protrusion forming die) First, the thin plate convex portion forming die KD1 will be described with reference to Fig. 1A and Fig. 1B. Fig. 1A is a schematic cross-sectional view showing a configuration example of the thin plate convex portion forming die KD1 for forming the positioning convex portion WcA according to the first embodiment. Fig. 1B is a partially enlarged view of Fig. 1A.

[0014] The thin plate convex forming die KD1 is used when forming a positioning convex part WcA on a workpiece Wa that is classified as a thin plate and has a thickness of less than 1.6 mm. The thin plate convex forming die KD1 includes a punch 11 and a die 12 having a counter 13. The punch 11 and the die 12 are attached to a turret punch press (not shown) or the like so that they are concentric and positioned opposite each other. When forming the positioning convex part WcA, the punch 11 moves (descends) toward the die 12 by the operation of the turret punch press, and cooperates with the counter 13, which is a die side member arranged at an opposing position, to sandwich and press the workpiece Wa.

[0015] A rectangular pilot hole Wa1 (see FIG. 1B) corresponding to the punch 11 is formed in advance in the workpiece Wa in a separate process. The punch 11 is positioned in the left-right direction so that only the right edge interferes with and processes the pilot hole Wa1. In FIG. 1B, the shape of the pilot hole Wa1 before processing by the punch 11 is shown by a dashed line. The part of the workpiece Wa that interferes with the punch 11 is referred to as a remaining part Rm of the protrusion forming material. Hereinafter, the remaining part Rm of the protrusion forming material is also referred to as a protrusion Rm.

[0016] The punch 11 is formed in a rectangular prism shape with an axis extending vertically. The punch 11 has a chamfered portion C on the lower edge portion that is chamfered with a C-face having a chamfer angle θc (see FIG. 1B). The chamfered portion C may be provided only on the right edge portion of the lower edge portion of the punch 11.

[0017] The die 12 has a flat upper surface that contacts the workpiece Wa, and a through hole is formed in a range corresponding to the punch 11, and a counter 13 is placed in the through hole so as to rise and fall. The counter 13 is biased upward by a spring (not shown). The counter 13 is subjected to a downward pressing force of the punch 11 against the biasing force, and is thereby lowered by a predetermined movement amount δ.

[0018] In processing the positioning protrusion WcA, the punch 11 descends, passes through the pilot hole Wa1, and abuts against the upper surface 13a of the counter 13. When the punch 11 further descends and reaches the lower end position of the descending range, the counter 13 has moved downward by a predetermined movement amount δ. At this time, as the punch 11 descends, the remaining protrusion forming material Rm of the workpiece Wa plastically flows so as to flow into the space extending in the front-to-rear direction (the front-to-back direction of the paper in FIG. 1B) between the chamfered portion C and the upper surface 13a of the counter 13. As a result, the remaining protrusion forming material Rm becomes the positioning protrusion WcA extending from the right edge of the pilot hole Wa1 in the lower left direction as shown in FIG. 1B.

[0019] The shape of the positioning protrusion WcA generally follows the shape of the chamfered portion C. That is, the positioning protrusion WcA is formed as a portion that extends in the front-rear direction corresponding to the front-rear width of the punch 11 at the right edge of the pilot hole Wa1 and extends downward and leftward.

[0020] In detail, the positioning protrusion WcA has a bottom surface X and an inclined surface XC in the cross-sectional shape of FIG. 1B. The bottom surface X is a surface formed in contact with the upper surface 13a of the counter 13, and the inclined surface XC is an inclined surface formed by rolling into the inclined surface of the chamfered portion C. Therefore, the protrusion angle θw, which is the angle formed by the bottom surface X and the inclined surface XC, is the same angle as the chamfer angle θc of the chamfered portion C. The positioning protrusion WcA extends obliquely downward and left from the end Wcs, which is the lower end of the right edge of the pilot hole Wa1 of the workpiece Wa, and is formed long in the front-rear direction. The chamfer angle θc is, for example, 30°.

[0021] The vertical length (height Wct) of the positioning protrusion WcA is determined by the predetermined movement amount δ of the counter 13. More specifically, the maximum value of the height Wct is the movement amount δ. Therefore, the height Wct of the positioning protrusion WcA can be set to a different height depending on the predetermined movement amount δ of the counter 13. For example, if the predetermined movement amount δ is 0.5 mm, the height Wct of the positioning protrusion WcA is formed to be a maximum of 0.5 mm from the lower end Wcs of the workpiece Wa.

[0022] (Configuration of KD2 thick plate protrusion forming die) Next, the thick plate protrusion forming die KD2 will be described with reference to Fig. 2A and Fig. 2B. Fig. 2A is a schematic cross-sectional view showing a configuration example of the thick plate protrusion forming die KD2 for forming the positioning protrusion WcB according to one aspect of this embodiment. Fig. 2B is a partial enlarged view of Fig. 2A. With reference to Fig. 2A and Fig. 2B, a configuration example of the thick plate protrusion forming die KD2 will be described.

[0023] The thick plate convex portion forming die KD2 is used when forming a positioning convex portion WcB on a workpiece Wb having a thickness of 1.6 mm or more, which is classified as a thick plate. The thick plate convex portion forming die KD2 has a different configuration of the die 22 from the thin plate convex portion forming die KD1.

[0024] The thick plate protrusion forming die KD2 includes a punch 21 and a die 22. The punch 21 has the same shape as the punch 11 of the thin plate protrusion forming die KD1. On the other hand, the die 22 does not include a member corresponding to the counter 13, and has a flat upper surface 22a that comes into contact with the punch 21 when it descends.

[0025] The workpiece Wb to be used for the thick plate protrusion forming die KD2 is different from the workpiece Wa to be used for the thin plate protrusion forming die KD1 only in thickness, and a similar pilot hole Wb1 is formed in advance in a different process. When forming the positioning protrusion WcB, the punch 21 moves (descends) toward the die 22 by the operation of a turret punch press (not shown), and presses the workpiece Wb between the punch 21 and the upper surface 22a of the die 22. The punch 21 is positioned in the left-right direction so that only the edge on the right side of FIG. 2B interferes with the pilot hole Wb1 and processes it. In FIG. 2B, the shape of the pilot hole Wb1 before processing by the punch 21 is shown by a dashed line. The part of the workpiece Wb that interferes with the punch 21 is referred to as the remaining part Rm of the protrusion forming material. Hereinafter, the remaining part Rm of the protrusion forming material is also referred to as the protrusion Rm.

[0026] Like punch 11, punch 21 is formed in a rectangular prism shape with an axis extending vertically. Punch 21 has a chamfered portion C on the lower edge portion, which is chamfered to have a C-face with a chamfer angle θc (see FIG. 2B). Chamfered portion C may be provided only on the right edge portion of the lower edge portion of punch 21.

[0027] In processing the positioning protrusion WcB, the punch 21 descends, passes through the pilot hole Wb1, and stops when it comes into contact with the upper surface 22a of the die 22. At this time, the workpiece Wb is sandwiched and pressed between the punch 21 and the die 22. At this time, as the punch 21 descends, the remaining protrusion forming material Rm of the workpiece Wb plastically flows so as to flow into the space extending in the front-rear direction between the chamfered portion C and the upper surface 22a of the die 22. As a result, the remaining protrusion forming material Rm becomes the positioning protrusion WcB extending leftward from the right edge of the pilot hole Wb1, as shown in FIG. 2B.

[0028] The shape of the positioning protrusion WcB generally follows the shape of the chamfered portion C. That is, the positioning protrusion WcB is formed as a portion that extends in the front-rear direction corresponding to the front-rear width of the punch 21 at the right edge of the pilot hole Wb1 and extends leftward.

[0029] Specifically, the positioning protrusion WcB has a bottom surface X and an inclined surface XC in the cross-sectional shape of Fig. 2B. It has a triangular cross-sectional convex shape consisting of the bottom surface X, which is in contact with the die 22 and is an extension of the lower surface of the workpiece Wb, and the inclined surface XC, which includes the slope of the chamfered portion C. The protrusion angle θw formed by the bottom surface X and the inclined surface XC is equal to the chamfer angle θc.

[0030] The reason for using the thin plate protrusion forming die KD1 and the thick plate protrusion forming die KD2 differently as described above is due to the amount of plastic deformation when forming the positioning protrusion Wc. The thicker the plate thickness t of the workpiece W, the greater the amount of plastic deformation of the remaining part Rm of the protrusion forming material when forming the positioning protrusion Wc. Therefore, when the workpiece W is a thick plate workpiece Wb, if a shape similar to the positioning protrusion WcA extending diagonally downward is formed by the thin plate protrusion forming die KD1, there is a high possibility of defects such as cracks or wrinkles occurring. Therefore, in the thick plate workpiece Wb, in order to reliably form the positioning protrusion Wc while suppressing the amount of plastic deformation, the positioning protrusion WcB is formed so that it does not extend diagonally so as to protrude from the surface, but extends in a direction along the extension direction of the workpiece Wb.

[0031] (Method of forming positioning protrusion Wc for first workpiece W1) Next, a method of forming a positioning protrusion Wc by selecting either the thin plate protrusion forming die KD1 or the thick plate protrusion forming die KD2 according to the plate thickness for the first workpiece W1, which is one of the two workpieces to be butt-welded, will be described with reference to Figs. 3A to 4D.

[0032] FIG. 3A is a first schematic plan view for explaining a first embodiment in a method for forming the positioning protrusion Wc. FIG. 3B is a second schematic plan view for explaining the first embodiment. FIG. 3C is a third schematic plan view for explaining the first embodiment. FIG. 3D is a fourth schematic plan view for explaining the first embodiment. FIG. 4A is a first schematic plan view for explaining a second embodiment in a method for forming the positioning protrusion Wc. FIG. 4B is a second schematic plan view for explaining the second embodiment. FIG. 4C is a third schematic plan view for explaining the second embodiment. FIG. 4D is a fourth schematic plan view for explaining the second embodiment.

[0033] The first workpiece W1 is cut out from a base material Bm of sheet metal. The base material Bm is an iron plate, and the base material Bm is distinguished by the reference numerals BmA, which is a thin plate, and BmB, which is a thick plate, when necessary. In addition, the positioning protrusions WcA and WcB are collectively referred to as the positioning protrusion Wc when no distinction is necessary.

[0034] (First embodiment) The first embodiment is a method for punching out the outer shape (contour) of the first workpiece W1 with a standard punching die. First, as shown in FIG. 3A, a plurality of rectangular openings BH are formed with the standard punching die along the contour of the first workpiece W1 laid out on the base material Bm. Micro joints Jm, which are minute connecting parts, are formed at the four corners of the first workpiece W1 to connect the first workpiece W1 to the part that will become the remaining material. In addition, the parts (two places) where the positioning protrusions WcA and WcB are formed do not form the openings BH, but are formed as wire joints Jw that are wider than the micro joints Jm to connect the first workpiece W1 to the part that will become the remaining material.

[0035] Next, as shown in Fig. 3B, the wire joint Jw is punched out using a rectangular standard punching die, leaving the edge of the first workpiece W1 slightly protruding. In Fig. 3B, the punching shape KDa of the standard punching die is shown by a solid line. The edge that is left protruding from the outline becomes the remaining part Rm of the protrusion forming material described above. The remaining part Rm of the protrusion forming material protrudes from the entire surface of the end face W1a of the first workpiece W1.

[0036] Next, as shown in Fig. 3C, a forming process is performed to form the positioning protrusions WcA, WcB by plastically deforming the remaining part Rm of the protrusion forming material using the thin plate protrusion forming die KD1 or the thick plate protrusion forming die KD2 as described above. In Fig. 3C, the punching shape KDb of the punching die is shown by a solid line. In the base material BmA, the positioning protrusion WcA is formed using the thin plate protrusion forming die KD1, and in the base material BmB, the positioning protrusion WcB is formed using the thick plate protrusion forming die KD2. The positioning protrusions WcA, WcB are formed by plastically deforming the protrusion Rm (remaining part Rm of the protrusion forming material) protruding from the entire surface of the end surface Wa1 of the first workpiece W1 so as to protrude from a part (lower part) of the end surface W1a by the punching down operation in which the punches 11, 21 moving in the thickness direction interfere.

[0037] This forming process forms the positioning protrusions Wc (WcA, WcB) shown in Fig. 3D. After that, the micro joints Jm are cut by a well-known method to obtain the first workpiece W1 having the positioning protrusions Wc.

[0038] Second embodiment The first workpiece W1 may be cut out from the base material Bm by a method other than punching with the above-mentioned standard punching die (first embodiment), and may be cut out by a laser beam cutting method (second embodiment) as described below.

[0039] 4A, the outline of the first workpiece W1 is cut by a laser beam, leaving the four corners as micro-joints Jm, which are minute connections. Here, the outline is cut so as to form protruding portions Mm that protrude in a rectangular shape to the left at the portions (two places) where the positioning protrusions Wc will be formed.

[0040] Next, as shown in FIG. 4B, a rectangular standard punching die is used to form a protrusion Mm that protrudes slightly from the contour of the first workpiece W1. This punching shape KDc1 is shown by a solid line. The part that is left by this forming and protrudes from the contour becomes the remaining part Rm (protrusion Rm) of the convex forming material already described. Furthermore, punching is performed on the adjacent front and rear sides so that they partially overlap with the punching shape KDc1. The respective punching shapes KDc2, KDc3 are shown by solid lines. This punching forms one opening BH2 as shown in FIG. 4C.

[0041] Next, in order to plastically deform the remaining part Rm of the protrusion forming material, the base material BmA is processed using a protrusion forming die KD1 for thin plates, and the base material BmB is processed using a protrusion forming die KD2 for thick plates. In Fig. 4C, this punch KDd is shown by a solid line.

[0042] This forms the positioning protrusion Wc shown in Fig. 4D. In more detail, as explained in Fig. 1B and Fig. 2B, the positioning protrusion WcA is formed in the base material BmA by the thin plate protrusion forming die KD1, and the positioning protrusion WcB is formed in the base material BmB by the thick plate protrusion forming die KD2. Thereafter, the micro joint Jm is cut by a well-known method to obtain the first workpiece W1 having the positioning protrusion Wc.

[0043] (Action and effect) As described above, according to one embodiment of the method for forming the positioning protrusions Wc, in the first step, the contour of the first workpiece W1 is cut out so as to form micro joints Jm, which are connecting parts that connect to the base material Bm, at the four corners. Therefore, the first workpiece W1 is maintained in a connected state with the base material Bm during the process of cutting the first workpiece W1 from the base material Bm. Therefore, the positioning protrusions Wc can be formed at predetermined positions on the contour of the first workpiece W1 while the base material Bm is being held. This allows the positioning protrusions Wc to be stably obtained with highly accurate shapes and dimensions.

[0044] In addition, in the process of forming the positioning protrusions Wc, the protrusions Rm are formed in advance at the positions where the positioning protrusions Wc are to be formed, thereby ensuring a sufficient volume of material for forming the positioning protrusions Wc by plastic deformation in the subsequent forming process.

[0045] Specifically, in the second step, the punches 11 and 21 interfere with the protruding parts Rm and Mm to plastically deform them, forming the protruding parts Rm and Mm. This forming process causes the protruding parts Rm to plastically flow, forming the positioning protrusions Wc extending from the end faces of the first workpiece W1. The cross-sectional shape of the positioning protrusions Wc is a tapered shape (approximately triangular) having an inclined surface XC and a bottom surface X. The inclined surface XC can be formed to have a protruding angle θw corresponding to the chamfering angle θc of the chamfered parts C at the tip edges of the punches 11 and 21. Furthermore, when the first workpiece W1 is a thin plate, the protruding amount (height Wct) of the positioning protrusions Wc in the thickness direction of the first workpiece W1 can be controlled by the downward movement amount δ of the punch 11 from the bottom surface of the first workpiece W1 during the downward stroke.

[0046] By controlling the projection angle θw and height Wct of the positioning projection Wc, the positioning projection Wc can be engaged with the positioning recess Wd formed on the surface of the second work W2 with high precision, as described later. This engagement allows the first work W1 and the second work W2 to be positioned with high precision without using a jig when they are butted against each other at a right angle. The first work W1 and the second work W2 can be the above-mentioned work W. That is, the first work W1 and the second work W2 are metal plates, such as iron plates or aluminum plates. The iron plates are, for example, cold-rolled steel plates (SPC) and stainless steel plates (SUS). The second work W2 does not have to be a plate material, and may be a block of iron or aluminum.

[0047] Next, the positioning recess Wd (see FIG. 6A) into which the above-mentioned positioning protrusion Wc engages and the recess forming die KD3 for forming the positioning recess Wd and its modified recess forming die KD3A will be described with reference to FIGS. 5A to 5D.

[0048] Fig. 5A is a schematic cross-sectional view showing a configuration example of a recess forming die KD3 for forming a positioning recess Wd according to one aspect of this embodiment. Fig. 5B is a partially enlarged view of Fig. 5A. Fig. 5C is a perspective view of a molding part 32P of the recess forming die KD3 as seen from the left front upper side. Fig. 5D is a schematic cross-sectional view showing a configuration example of a recess forming die KD3A which is a modified example of the recess forming die KD3.

[0049] (Configuration of the recess forming die KD3) The positioning accuracy of the first work W1 and the second work W2, which are positioned by the engagement between the positioning protrusions Wc and the positioning recesses Wd, improves as the gap between the positioning protrusions Wc and the positioning recesses Wd is reduced. Therefore, it is desirable that the shape and dimensions of the positioning recesses Wd be the same as those of the positioning protrusions Wc, but with the protrusions and recesses reversed.

[0050] In other words, it is desirable that the shape of the forming portion for forming the positioning recess Wd in the die is substantially the same as the shape and dimensions of the positioning protrusion Wc formed in the first workpiece W1.

[0051] In this preferred embodiment, the molded portion of the die has a long side, protrudes linearly, and has a tapered shape with a protrusion angle θw. The protrusion angle θw is the same as the chamfer angle θc, and is an acute angle of, for example, about 30°. Therefore, the tip of the molded portion is likely to have defects such as cracking due to the force applied during molding or chipping due to wear. Therefore, the recess molding die KD3 is designed to suppress the occurrence of defects at the tip and to mold the positioning recess Wd as a recess that can be positioned with high precision.

[0052] As shown in Fig. 5A, the recess forming die KD3 includes a punch 31 and a die 32. The punch 31 has a flat surface 31a at its lower end that contacts the second workpiece W2 with a flat surface. The die 32 has a forming portion 32P as a portion that forms the positioning recess Wd. The tip of the forming portion 32P is a tip portion 32T.

[0053] The punch 31 and the die 32 are attached to a turret punch press (not shown) or the like so as to be positioned opposite each other with the axis CL3 being concentric. When forming the positioning recess Wd, the punch 31 moves (descends) toward the die 32 by the operation of the turret punch press, and cooperates with the die 32 arranged at the opposing position to sandwich and press the second workpiece W2.

[0054] As shown in Fig. 5B, the molded portion 32P has a triangular cross section that protrudes upward and is formed like a rib extending in the front-rear direction (the front-rear direction of the paper in Fig. 5B). The angle θp of the tip 32T is set to be larger than the protrusion angle θw (see Figs. 1B and 2B) of the positioning protrusion Wc. Specifically, the angle θp is set to an angle obtained by dividing the axis CL3 that extends in the up-down direction and passes through the tip 32T into left and right by the protrusion angle θw. In other words, the angle θp = (protrusion angle θw) x 2.

[0055] In this way, the angle formed by the cross-sectional shape of the tip 32T of the molded portion 32P is larger than that of the positioning protrusion Wc having substantially the same shape and dimensions. Therefore, defects such as cracks and chipping are less likely to occur in the tip 32T. As shown in Figures 5B and 5C, the molded portion 32P has a slope S31 and a slope S32. The slope S31 forms one recess slope Sd3 of the positioning recess Wd, and the slope S32 forms the other recess slope Sd4. The slope S31 is formed as a slope that comes into contact with the slope XC of the positioning protrusion Wc when the positioning protrusion Wc engages with the positioning recess Wd.

[0056] A recess 32H is formed on the inclined surface S32 of the forming portion 32P. The recess 32H has a peripheral shape when a cylinder having an axis extending in the vertical direction is carved into the inclined surface S32 from left to right. A positioning recess Wd having a V-shaped cross section is formed by the forming portion 32P, and the material of the second workpiece W2 flows into the recess 32H by plastic flow. Therefore, a protrusion Wp (see Figs. 6A and 6B) is formed on the inclined surface S32. Therefore, the positioning recess Wd is formed as a groove having an inclination angle θ3 equivalent to the protrusion angle θw at the most protruding position of the protrusion Wp, as shown in Fig. 6B. The peripheral surface Wp1 of the protrusion Wp is a surface extending in the vertical direction.

[0057] The positioning recess Wd is formed such that the cross-sectional shape of the portion where the protrusion Wp is not formed is a V-shape with both opposing surfaces inclined. The angle θd of this V-shape is the same as the angle θp of the tip 32T of the recess forming die KD3. As a result, when the positioning protrusion Wc formed on the first workpiece W1 is engaged so that its inclined surface XC closely contacts the recess inclined surface Sd3 of the positioning recess Wd, the bottom surface X of the positioning protrusion Wc becomes a surface extending in the up-down and front-rear directions. In other words, the bottom surface X is in line contact with the most protruding portion of the peripheral surface Wp1 of the protrusion Wp.

[0058] In this manner, when the positioning protrusion Wc is engaged with the positioning recess Wd, the inclined surface XC of the positioning protrusion Wc comes into surface contact with the recess inclined surface Sd3 of the positioning recess Wd, and the bottom surface X of the positioning protrusion Wc comes into line contact with the peripheral surface Wp1 of the protrusion Wp of the positioning recess Wd.

[0059] The inclined surface XC, bottom surface X, recessed slope Sd3, and peripheral surface Wp1 are all surfaces directly formed by the mold, and therefore are formed stably and with high precision. As a result, the positioning protrusion Wc and the positioning recess Wd are positioned with high precision in the left-right direction when engaged. In addition, the engagement is wedge-shaped, narrowing downward. Therefore, by engaging the first work W1 with the second work W2 from above, the positioning protrusion Wc engages so as to bite into the positioning recess Wd due to the weight of the first work W1. As a result, the first work W1 maintains a stable engagement with the second work W2 without any rattling.

[0060] Next, the schematic configuration of a recess forming die KD3A, which is a modification of the recess forming die KD3, will be described with reference to Fig. 5D. The recess forming die KD3A has a forming part 31AP on the punch side, instead of the forming part 32P on the die side of the recess forming die KD3.

[0061] 5D, the recess forming die KD3A includes a punch 31A and a die 32A that are disposed opposite each other with an axis CL3A being coaxial therewith. The punch 31A has a punch case 31A1 and a punch main body 31A2. The punch body 31A2 is raised and lowered by a drive unit (not shown) relative to the punch case 31A1. The punch body 31A2 has a forming portion 31AP on the lower surface. The forming portion 31AP has the same shape as the forming portion 32P shown in Figures 5A to 5C, including the recessed portion 32H, and is formed on the punch side, so that the forming portion 31AP is oriented upside down. On the other hand, the upper surface 32Aa of the die 32A is a flat surface.

[0062] When forming the recess Wd, the workpiece W2 is sandwiched and held between the punch case 31A1 and the die 32A of the punch 31A, and the punch body 31A2 is lowered so that the forming part 31AP forms the recess Wd on the surface of the workpiece W2 facing the punch 31A. This recess Wd has the same shape as the recess Wd formed by the recess forming die KD3.

[0063] (Method of forming positioning recess Wd) (First molding method) Next, an example of a method for forming the positioning recesses Wd in the second workpiece W2 will be described with reference to FIGS. 7A to 8C.

[0064] FIG. 7A is a schematic plan view showing a first step of a first molding method example of the positioning recess Wd according to one aspect of this embodiment. FIG. 7B is a schematic plan view showing a second step of a first molding method example of the positioning recess Wd according to one aspect of this embodiment. FIG. 7C is a schematic plan view showing a third step of a first molding method example of the positioning recess Wd according to one aspect of this embodiment. FIG. 8A is a schematic plan view showing a first step of a second molding method example of the positioning recess Wd according to one aspect of this embodiment. FIG. 8B is a schematic plan view showing a second step of a second molding method example of the positioning recess Wd according to one aspect of this embodiment. FIG. 8C is a schematic plan view showing a third step of a second molding method example of the positioning recess Wd according to one aspect of this embodiment.

[0065] First, a first method for forming a positioning recess according to one aspect of this embodiment will be described with reference to FIGS. 7A to 7C.

[0066] (First molding method) Fig. 7A shows the first step. In the first step, the base material Bm is stamped using a recess forming die KD3 to form positioning recesses Wd at predetermined positions and in a predetermined number spaced apart in a straight line. The positioning recesses Wd are formed so that the protrusions Wp are on the left side (upper side of the paper in Fig. 7A). Since the processing in the first step is stamping, a bulge B (dashed line) that bulges in the thickness direction is generated in a portion adjacent to the positioning recesses Wd.

[0067] FIG. 7B shows the second step. In the second step, a crushing process is performed to crush the bulge B that occurred in the first step. The bulge B occurs when the material in the hollowed-out portion of the positioning recess Wd plastically flows and expands in the thickness direction. In the second step, a general die used for crushing is used. By the crushing process, the material in the bulged portion plastically flows uniformly into the surrounding members, and the degree of bulging is suppressed to a level that does not cause practical problems, and the bulge is essentially flattened.

[0068] FIG. 7C shows the third step. In the third step, the second workpiece W2 is cut out from the base material Bm by punching using a standard punching die or by cutting using a laser beam. At this time, the four corners of the second workpiece W2 form micro-joints Jm as connecting parts that connect to the base material Bm. FIG. 7C shows an example in which the contour is cut by forming openings BH3 using a standard punching die to form the micro-joints Jm. The micro-joints Jm are cut in the final stage of processing, and the second workpiece W2 is separated from the base material Bm. This results in the second workpiece W2 having positioning recesses Wd.

[0069] Next, a second method for forming the positioning recess Wd according to one aspect of this embodiment will be described with reference to FIGS. 8A to 8C.

[0070] (Second molding method) 8A to 8C are schematic diagrams (first to third steps) showing a second molding method for molding a recess into which a positioning protrusion engages according to one aspect of this embodiment. This molding method differs from the first molding method in the first and second steps. Therefore, only the differences will be described.

[0071] FIG. 8A shows the first step in the second forming method. In the first step, a hole H, which is a through hole, is formed at a position outside the outer periphery (contour) of the second work W2 corresponding to the position where the positioning recess Wd is formed. The hole H is formed as a material escape so that the material corresponding to the recess can easily plastically flow without affecting the thickness when the positioning recess Wd is formed. The hole H is formed by punching using a standard punching die. This allows the material that has lost its place due to the plastic flow that occurs when forming the positioning recess Wd to escape by deforming the hole H. Therefore, the bulge B that occurs in the first forming method does not occur substantially.

[0072] FIG. 8B shows the second step. The second step is the same as the first step of the first forming method. FIG. 8C shows the third step. The third step is the same as the third step of the first forming method. As in the case of the first forming method, after the third step, the micro joints Jm are cut in the final stage, and the second workpiece W2 is separated from the base material Bm. This results in a second workpiece W2 having a positioning recess Wd. The hole H is formed in the material to be punched when the contour is punched out with a standard punching die, and remains in the remaining material when laser cutting. Therefore, the hole H does not remain in the shape of the second workpiece W2.

[0073] As described above, according to one embodiment of the method for forming a positioning recess, a positioning recess Wd having a V-shaped cross section can be formed using a recess forming die KD3. The positioning recess Wd has one recess slope Sd3 against which the sloped surface XC of the positioning protrusion Wc abuts, and the other recess slope Sd4 formed to include a protrusion Wp that contacts the bottom surface X of the positioning protrusion Wc.

[0074] Specifically, when the positioning recess Wd engages with the positioning protrusion, one recess slope Sd3 comes into close contact with the inclined surface XC of the positioning protrusion Wc, and the protrusion Wp formed on the other recess slope Sd4 comes into line contact with the bottom surface X. Therefore, the positioning recess Wd can substantially eliminate the gap when the positioning protrusion Wc engages. This allows the first work W1 and the second work W2 to be positioned with high accuracy when they are butted against each other at a right angle.

[0075] (Positioning structure GK) The positioning structure GK, which positions the first work W1 and the second work W2 by the concave-convex engagement between the above-mentioned positioning convex portion Wc and positioning concave portion Wd, will be described with reference to Figures 9A to 10B, which show the state in which the first work W1 is orthogonally butted against the second work W2.

[0076] Fig. 9A is a top view for explaining the positioning structure GK for the thick workpiece Wb. Fig. 9B is a cross-sectional view at position BB in Fig. 9A. Fig. 10A is a top view for explaining the positioning structure GK for the thin workpiece Wa. Fig. 10B is a cross-sectional view at position CC in Fig. 10A. Fig. 10C is a perspective view for explaining the positioning structure GK for the thin workpiece Wa.

[0077] 9A and 9B, the positioning structure GK for the thick plate workpiece Wb is a positioning structure for orthogonally butting the end surface W1a of the first workpiece W1, which is a thick plate, at a predetermined position near the end of the surface W2b (upper surface W2b) of the second workpiece W2. The positioning structure GK for the thick plate has a positioning protrusion WcB formed in the first workpiece W1 and a positioning recess Wd formed in the upper surface W2b of the second workpiece W2.

[0078] The positioning recess Wd has one recess inclined surface Sd3, which in this example is the end side, formed at the same inclination angle as the inclined surface XC of the positioning protrusion WcB, and the other recess inclined surface Sd4 is formed to include a protrusion Wp having a circumferential surface extending in the vertical direction that makes line contact with the bottom surface X of the positioning protrusion WcB at position Pw.

[0079] As a result, when the positioning protrusion WcB is engaged with the positioning recess Wd, the positioning protrusion WcB is embedded in and engaged with the positioning recess Wd, and the first work W1 and the second work W2 can be positioned without using a jig in a state where they are butted together at a right angle. The left-right position of the first work W1 that is butted against the second work W2 is determined according to the left-right position of the positioning recess Wd. FIG. 9B shows a so-called half-pull butting state in which half of the end face W1a of the first work W1 is butted against the second work W2. In contrast, by forming the positioning recess Wd further to the right in the second work W2, it is possible to achieve a so-called one-sided butting state in which the entire end face W1a is butted against the second work W2.

[0080] 10A to 10C, the positioning structure GK for the thin workpiece Wa is a positioning structure when the end face W1a of the first workpiece W1, which is a thin plate, is orthogonally butted against a predetermined position near the end of the top face W2b of the second workpiece W2. The positioning structure GK for the thin plate has a positioning protrusion WcA formed in the first workpiece W1 and a positioning recess Wd formed in the top face W2b of the second workpiece W2.

[0081] As in the case of thick plates, the positioning recess Wd has one recess inclined surface Sd3, which in this example is the end side, formed at the same inclination angle as the inclined surface XC of the positioning protrusion WcA, and the other recess inclined surface Sd4 is formed to include a protrusion Wp having a circumferential surface extending in the vertical direction that makes line contact with the bottom surface X of the positioning protrusion WcB at position Pw.

[0082] As a result, as shown in FIG. 10C, by engaging the positioning protrusion WcA with the positioning recess Wd, the positioning protrusion WcA is embedded and engaged in the positioning recess Wd, and the first work W1 and the second work W2 can be positioned without using a jig in a state where they are butted together at a right angle. The left-right position of the first work W1 that is butted against the second work W2 is determined according to the left-right position of the positioning recess Wd. FIG. 10B shows a so-called half-pull butting state in which half the surface in the thickness direction of the end face W1a of the first work W1 is butted against the second work W2. On the other hand, by forming the positioning recess Wd further to the right in the second work W2, it is possible to achieve a so-called one-sided butting state in which the entire surface of the end face W1a is butted against the second work W2.

[0083] In addition, since the first workpiece W1, which is a thin plate, has a positioning protrusion WcA formed to protrude to the right from the surface as shown in Figure 10B, the abutment position of the first workpiece W1 can be positioned further to the left than in the case of a thick plate.

[0084] The positioning structure GK in the thin workpiece Wa differs from the positioning structure GK in the thick workpiece Wb in the thickness direction where the positioning protrusion Wc is formed in the first workpiece W1. Specifically, the positioning protrusion Wc (WcB) in the case of a thick plate is formed so as to extend from the end face within the thickness range of the first workpiece W1. On the other hand, the positioning protrusion Wc (WcA) in the case of a thin plate is formed so as to extend from the end face and protrude in the thickness direction from the surface beyond the thickness range of the first workpiece W1. Therefore, the positioning structure GK in the thin workpiece Wa can correspond to the positioning method shown in Figures 11A and 11B described next. The positioning structure GK in the thin workpiece Wa can position the first workpiece W1 to abut against the second workpiece W2 in a desired positional relationship without using a jig, as in the case of a thick plate.

[0085] (Positioning structure GK2) Using the positioning recess Wd described above, the first work W1 having a convex portion that engages with the positioning recess Wd can be superimposed on the second work W2 and positioned. This positioning structure for superimposing is called a positioning structure GK2 and will be described with reference to Figures 11A to 11C.

[0086] Fig. 11A is a partial cross-sectional view for explaining the positioning structure GK2, Fig. 11B is a cross-sectional view for explaining a first mode of the positioning structure GK2, and Fig. 11C is a cross-sectional view for explaining a second mode of the positioning structure GK2.

[0087] 11A, the second workpiece W2 is formed with a positioning recess Wd having a protrusion Wp. This positioning recess Wd is the same as the positioning recess Wd in the positioning structure GK. On the other hand, the first workpiece W1 is formed with a positioning protrusion WcC that engages with the positioning recess Wd. The positioning protrusion WcC protrudes in the thickness direction (downward) from the right edge of the first workpiece W1 and is formed long in the front-rear direction (front-rear direction of the paper).

[0088] The positioning protrusion WcC is formed by filling burrs generated when forming the right edge of the first workpiece W1 by punching, into gaps in a mold of a predetermined shape with plastic flow. The positioning protrusion WcC has a cross-sectional shape formed in a tapered triangular shape with the apex at the bottom, and has a bottom surface X extending in the thickness direction of the first workpiece W1, and an inclined surface XC inclined with respect to the bottom surface X and extending at the same inclination angle as the recessed surface Sd3 of the positioning recess Wd.

[0089] The first work W1 is positioned relative to the second work W2 by engaging the positioning protrusion WcC with the positioning recess Wd from above, with the surfaces overlapping each other instead of the end faces. In detail, the positioning protrusion WcC is embedded in the positioning recess Wd, and the lower surface W1b of the first work W1 and the upper surface W2b of the second work W2 come into contact and overlap. At that time, the inclined surface XC and the bottom surface X of the positioning protrusion WcC embedded in the positioning recess Wd come into contact with the recessed slope Sd3 of the positioning protrusion Wd and the circumferential surface Wp1 extending in the thickness direction of the protrusion Wp, respectively. As a result, the left-right position of the first work W1 relative to the second work W2 is determined with high accuracy. The front-rear position of the first work W1 can be positioned with high accuracy by minimizing the gap in the front-rear direction of the recessed-rear engagement because the positioning protrusion WcC and the positioning recess Wd are directly molded by a mold, respectively.

[0090] The first embodiment of the positioning structure GK2 is shown in Fig. 11B. The first work W1 is formed with positioning protrusions WcC at both the left and right ends, and the second work W2 is formed with a positioning recess Wd having a protrusion Wp as a recess that engages with one of the pair of positioning protrusions WcC formed on the first work W1, and the recess that engages with the other is a positioning recess WdC without the protrusion Wp. In the first mode, the first work W1 engages with the second work W2 at two locations, the left and right ends, and thus rotation about the vertical axis as well as the left and right directions is well regulated, stabilizing the positioning of the overlapping. In addition, one of the two engagement locations is a positioning recess Wd having a protrusion Wp, so the left and right position of the first work W1 can be determined with high precision without using a jig.

[0091] The second embodiment of the positioning structure GK2 is shown in Fig. 11C. The first work W1 is not simply a flat plate, but has a bent portion W1d bent upward at the left edge, giving it a three-dimensional shape in which a positioning protrusion cannot be formed. Even in this case, by using a positioning recess Wd having a protrusion Wp for engagement with the recesses at one edge (the right edge in Fig. 11C), the three-dimensional first work W1 can be positioned with high precision when overlapping it with the second work W2 without using a jig.

[0092] (Welding mode) An example of butt welding possible with the positioning structure GK for a thick workpiece Wb or the positioning structure GK for a thin workpiece Wa will be described with reference to Figs. 11A and 11B. Fig. 11A is a schematic side view showing a single-pull welding mode that can be handled by the positioning structure GK according to one embodiment of the present invention. Fig. 11B is a schematic side view showing a half-pull welding mode that can be handled by the positioning structure GK according to one embodiment of the present invention.

[0093] 11A shows a single-pull welding mode. The positioning protrusion WcA or WcB formed on the first work W1 is engaged with the positioning recess Wd formed on the second work W2, and the first work W1 and the second work W2 are butted together at a right angle. The left-right position of the positioning recess Wd is set by single-pull welding, where the entire end surface W1a of the first work W1 abuts against the top surface W2b of the second work W2.

[0094] Next, the butted portions of the first workpiece W1 and the second workpiece W2 are welded to form a welded portion WS. In this manner, the first workpiece W1 and the second workpiece W2 can be butt-welded by one-way pull without using a jig, which reduces the jig cost and the time required to set up the jig.

[0095] The butting range of the end surface W1a of the first work W1 against the upper surface W2b of the second work W2 can be varied depending on the position of the positioning recess Wd in the left-right direction. By forming the positioning recess Wd in the second work W2 at a position further left than that shown in Fig. 11A, so-called half-pull butt welding as shown in Fig. 11B is possible.

[0096] As described above, the butting position of the first work W1 against the second work W2 depends on the formation position of the positioning recess Wd. That is, when the first work W1 has the positioning protrusion WcA, the most protruding position where the bottom surface X of the positioning protrusion WcA of the protrusion Wp of the positioning recess Wd contacts is set to a position obtained by adding the height Wct of the positioning protrusion WcA to the right from the position of the surface (the right surface in FIG. 10B) on the side where the positioning protrusion WcA is formed in the first work W1.

[0097] Furthermore, when the first workpiece W1 has a positioning protrusion WcB, the most protruding position where the bottom surface X of the positioning protrusion WcB of the protrusion Wp of the positioning recess Wd comes into contact is set to the position of the surface of the first workpiece W1 on which the positioning protrusion WcB is formed (the right surface in FIG. 9B). The positioning protrusion WcB can be considered as having a height Wct of 0 (zero). In other words, the height Wct can be freely set between 0 (zero) and a maximum movement amount δ.

[0098] The first work W1 and the second work W2 are positioned with high accuracy in the thickness direction of the first work W1 (left and right direction in Fig. 9B and Fig. 10B) because the positioning protrusion Wc and the positioning recess Wd formed directly by the mold are engaged with each other by a combination of a surface and a slope perpendicular to the thickness direction. In addition, the positioning accuracy of the first work W1 in the extension direction along the second work W2 (front-rear direction, i.e., the front-rear direction of the paper in Fig. 9B and Fig. 10B) depends on the gap in the front-rear direction when the positioning protrusion Wc and the positioning recess Wd are engaged. This gap is generated based on the difference in the length between the protrusion Rm and the recess slope Sd3 in the front-rear direction. However, since the protrusion Rm and the recess slope Sd3 are directly formed by the mold, the difference in length can be made small enough to be practically unproblematic. Therefore, the positioning of the first work W1 in the extension direction along the second work W2 is performed with high accuracy. In addition, the positioning of the first work W1 and the second work W2 in the butting direction (the vertical direction in Fig. 9B and Fig. 10B) is achieved by the contact of the end faces and the front surfaces, and therefore can be achieved with sufficient accuracy. In this way, the first work W1 and the second work W2 are positioned with high accuracy in all three axial directions by the engagement of the positioning protrusions Wc and the positioning recesses Wd without using a jig.

[0099] An example of a welding mode in the positioning structure GK2 is shown in Fig. 12C. Fig. 12C is a schematic cross-sectional view showing an example of a welding mode in the positioning structure GK2. The edge of the first work W1, which is positioned with respect to the second work W2 by the overlapping positioning structure GK2 so that their surfaces overlap, is welded by forming a welded part WS by fillet welding. In this way, the first work W1 and the second work W2 can be welded in an overlapping state without using a jig, so that the jig cost and the jig setting time can be reduced.

[0100] As described in detail above, a first aspect of the present invention is a positioning structure GK comprising a positioning protrusion Wc formed to protrude from an end face W1a of a first sheet metal workpiece W1, and a positioning recess Wd formed in the surface of a second workpiece W2 so that the positioning protrusion Wc is embedded and engages with the surface of the second workpiece W2, and by engaging the positioning protrusion Wc with the positioning recess Wd, the first workpiece W1 is positioned in an attitude perpendicular to the second workpiece W2 by having its end face W1a abut against the surface W2b of the second workpiece W2.

[0101] This allows the first workpiece W1 to be positioned relative to the second workpiece W2 without using a jig, thereby reducing the cost of the jig and the time required to set up the jig in the positioning operation.

[0102] Moreover, a second aspect of the present invention is a method for manufacturing a workpiece in which a positioning protrusion Wc of a first workpiece W1 is engaged with a positioning recess Wd formed in a second workpiece W2 to position the second workpiece W2 in an orthogonal orientation relative to the second workpiece W2, in which the positioning protrusion Wc is formed by forming a protrusion Rm that protrudes from the entire surface of an end face W1a of the first workpiece W1 made of sheet metal, and a punch 11 moving in the thickness direction of the first workpiece W1 moves in the thickness direction at a position where it interferes with the protrusion Rm, thereby plastically deforming the protrusion Rm so that it protrudes from a portion of the end face W1a.

[0103] This allows the first workpiece W1 to be positioned relative to the second workpiece W2 and the two components to be butt-welded without using a jig, thereby reducing the cost of jigs used in positioning during the welding operation and the time required to set up the jigs.

[0104] In this second embodiment, a chamfered portion C may be formed on the tip edge of the punch 11, and the positioning convex portion Wc may be formed into a tapered shape having an inclined surface XC corresponding to the chamfered portion C and a bottom surface X corresponding to the top surface 13a by plastically flowing the protrusion Rm into the gap between the chamfered portion C and the top surface 13a of the die side member 13 with which the tip surface of the punch 11 abuts.

[0105] As a result, the positioning protrusions Wc are formed with a highly accurate and stable shape because the shape is directly formed by the surface of the die, and the positioning accuracy of the first work W1 relative to the second work W2 is improved.

[0106] Moreover, a third aspect of the present invention is a welding method in which a protrusion Rm protruding from the entire surface of an end face W1a of a first workpiece W1 made of sheet metal is formed, a punch 11 moving in the thickness direction of the first workpiece W1 is moved in the thickness direction at a position where it interferes with the protrusion Rm, and the protrusion Rm is plastically deformed so as to protrude from a part of the end face W1a to form a positioning protrusion Wc, a positioning recess Wd in which the positioning protrusion Wc is embedded and engages is formed on the surface W2b of a second workpiece W2 against which the end face W1a of the first workpiece W1 is abutted, at a position shifted by the height Wct of the positioning protrusion Wc from a predetermined position against which the first workpiece W1 is abutted, and the positioning protrusion Wc is engaged with the positioning recess Wd to position the first workpiece W1 at a predetermined position of the second workpiece W2 and abut them, and the abutted portion is welded to join the first workpiece W1 and the second workpiece W2.

[0107] This allows the first workpiece W1 to be positioned relative to the second workpiece W2 and the two components to be butt-welded without using a jig, thereby reducing the cost of jigs used in positioning operations and the time required to set up the jigs during the welding operation.

[0108] The embodiment of the present invention is not limited to the above-mentioned configuration, and may be modified without departing from the spirit and scope of the present invention.

[0109] The shape of the molded portion 32P is not limited to the above shape. The shape of the molded portion 32P may be such that at least one of the inclined surfaces S31 is in close contact with the inclined surface XC of the positioning protrusion Wc. The surface shape of the recessed portion 32H does not need to be cylindrical, and may be a square tube. The recessed portion 32H may be provided at any position in the front-rear direction of the molded portion 32P, and may be provided independently in a plurality of positions.

[0110] The forming portion 32P may not have the recessed portion 32H, and the inclination angle θ1 of the inclined surface S31 and the inclination angle of the inclined surface S32 with respect to the orthogonal plane including the axis CL3 (angle θp-inclination angle θ1) may be different. The number of pairs of the positioning protrusion Wc and the positioning recess Wd that engage between the first work W1 and the second work W2 is not limited to two pairs as described above, and may be one pair. In addition, when the end faces to be butted against each other are long, three or more pairs may be used. [Explanation of symbols]

[0111] 11 Punch 12 Die 13 Counter 13a Top side 21 Punch 22 Die 22a Top side 31,31A Punch 31A1 Punch Case 31A2 Punch body 31a Flat surface part 32,32A die 32Aa top surface 32H recess 32P,31AP molding part 32T tip Bm,BmA,BmB Base material BH,BH2,BH3 opening C Chamfered part CL3,CL3A axis line GK positioning structure H hole Jm Micro joint (connection part) Jw Wire Joint KDa, KDb, KDc1, KDc2, KDc3, KDd Punching shape KD1 Thin plate convex part forming die KD2 Thick plate convex forming die KD3, KD3A Concave forming mold Mm protrusion Pw position Rm Protruding part (remaining part of molding material for convex part) S31, S32 slope Sd3, Sd4 Concave slope t Plate thickness W,Wa,Wb Work Wa1,Wb2 prepared hole Wc, WcA, WcB, WcC Positioning protrusions Wcs end Wct Height Wd, WdC Positioning recess Wp protrusion Wp1 Peripheral surface WS Welding W1 First Work W1a end face W1b bottom side W1d Bending part W2 2nd Work W2b Top surface (front surface) X Bottom XC slope δ Travel amount θc Chamfer angle θp angle θw Projection angle θ1 Tilt angle

Claims

1. a positioning protrusion formed to protrude from an end surface of a first workpiece made of sheet metal; a positioning recess formed on a surface of a second workpiece at a position offset by a protruding height of the positioning protrusion from the surface of the first workpiece with respect to a predetermined abutting position of the first workpiece so that the positioning protrusion is embedded and engaged therewith; A positioning structure in which the first workpiece is positioned in a perpendicular orientation to the second workpiece by engaging the positioning protrusion with the positioning recess with its end face abutting against the surface of the second workpiece.

2. A method for manufacturing a workpiece, comprising: engaging a positioning protrusion of a first workpiece with a positioning recess formed in a second workpiece to position the first workpiece in an orthogonal orientation with respect to the second workpiece, The positioning protrusion, forming a protruding portion that protrudes from the contour of the first workpiece of sheet metal over the entire thickness direction of the end surface; A method for manufacturing a workpiece, comprising the steps of: forming a chamfered portion on the tip edge of a punch that moves in the thickness direction of the first workpiece; moving the punch in the thickness direction at a position where it interferes with the protrusion, and plastically deforming the protrusion to protrude from a part of the end face; and during the plastic deformation, plastically flowing the protrusion into the gap between the chamfered portion and an upper surface of a die side member with which the tip surface of the punch abuts, thereby forming the protrusion into a tapered shape having an inclined surface corresponding to the chamfered portion and a bottom surface corresponding to the upper surface.

3. forming a protruding portion protruding from the contour of the first workpiece of sheet metal over the entire thickness direction of the end face; a punch moving in a thickness direction of the first workpiece is moved in the thickness direction at a position where the punch interferes with the protruding portion, and the protruding portion is plastically deformed so as to protrude from a part of the end surface to form a positioning convex portion; a positioning recess in which the positioning protrusion is embedded and engaged is formed at a position shifted by a height of the positioning protrusion from a predetermined position where the first work is abutted on a surface of a second work against which the end face of the first work is abutted, A welding method in which the positioning convex portion is engaged with the positioning concave portion to position the first workpiece at the predetermined position of the second workpiece, and the first workpiece and the second workpiece are butted together by welding the butted portion.

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