JP2013013934A - Method for manufacturing metal component with three-dimensional edge - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for manufacturing a metal component with a three-dimensional edge without cracking and wrinkles from a high-strength metal blank by a simple forming process.SOLUTION: The method includes: a folding shape applying process for applying a fold line of either a mountain fold or a valley fold (a mountain-fold line 4 or a valley-fold line) along a curve to a curved edge part 3; and a three-dimensional forming process for three-dimensionally forming the curved edge part 3 with the fold line as a starting point by moving a portion of the blank 10 at both ends 1, 2 of the curved edge part 3 so that an interval of both the ends is narrowed or widened.

Description

  The present invention relates to a method of manufacturing a metal part with a three-dimensional edge, and more specifically, a curved edge provided on a blank of a metal plate (for example, a high-strength steel plate having a tensile strength (TS) of 590 MPa or more) or further adjacent thereto. The present invention relates to a method of manufacturing a metal part with a three-dimensional border, in which a blank part is three-dimensionalized by forming to form a metal part with a three-dimensional border. Here, the solid at the three-dimensional edge is a vertical wall, a mountain shape, or a solid in which one of them is connected to the other. The blank is a raw material for forming, and is a single flat plate cut out from an original plate and provided with a planar contour shape corresponding to the three-dimensional shape after the forming process.

  Conventionally, as a means to obtain a metal part with a three-dimensional vertical wall, for example, at the bent edge, press molding (hereinafter referred to as conventional press molding) in which various forms of bending, drawing, and stretch flange are combined with a single metal plate has been performed. As a method for obtaining dimensional accuracy, a method of providing a stepped shape at the end of the vertical wall (Patent Document 1) and a method of forming the flange part in two stages (Patent Document 2) have been proposed to prevent twisting. As a method for this, a method of performing bending molding in two stages (Patent Document 3) and a method of applying stress to a vertical wall (Patent Document 4) have been proposed.

JP 2010-5651 A JP 2006-289480 A JP 2009-241109 A JP 2006-305627 A

  Increasing the strength of steel sheets in response to demands for weight reduction leads to a reduction in steel sheet drawing, overhanging, and stretch flangeability. When a high-strength steel sheet blank is formed and a part with a solid wall, for example a vertical wall, is produced, if the edge is straight, it can be formed into a vertical wall by bending. When the part is curved, if you try to form a vertical wall by normal press molding (stretch flange molding or draw molding), the blank edge side boundary curve and the bent part side boundary of the edge region to be the vertical wall part Since the line length differs from the curve, cracks occur when stretch flange molding is performed, and wrinkles occur when draw molding is performed. At this time, by optimizing the molding conditions such as wrinkle pressing or changing the part shape, it is possible to suppress the generation of wrinkles to a certain extent, but such a method can be used to meet the need for weight reduction, for example, It can be said that there is a limit to cope with further increase in strength of 980 MPa or more in TS.

In addition, there are problems such as forming in two stages, providing a step in the vertical wall portion, applying stress to the vertical wall portion, etc., and there are problems such as an increase in processes and a decrease in yield. Since the cracks and wrinkles are caused by the line length difference between the blank edge side boundary curve and the bent portion side boundary curve of the edge region to be the vertical wall, it cannot be a countermeasure against cracks and wrinkles.
That is, in the manufacturing method of the solid edged metal part that three-dimensionalizes the bent edge by the conventional press forming, when the blank is a high-strength steel plate, it is broken in a simple process, and wrinkles are generated and the target shape of the solid edged metal part is formed. There is a problem that it is extremely difficult to achieve both process simplification and product weight reduction.

  The inventors studied means for solving the above-mentioned problems, and obtained the following knowledge using origami as a hint. That is, although paper is a material that does not stretch or shrink, a solid body having a curved ridgeline at the edge of the paper blank can be formed by a simple folding method. By applying the folding method to the metal blank, the work material is bent and deformed with little deformation of the drawing, overhanging, and stretch flange. It is possible to produce metal parts with no solid edges.

The present invention has been made based on the above findings, and the gist thereof is as follows.
(1) A metal part with a three-dimensional edge formed from a blank cut out from a metal plate and having curved curved edges with both ends, and the bent edge part or further the blank part adjacent to the bent edge part into a three-dimensional shape A method of manufacturing a metal part with a three-dimensional edge,
A bent shape imparting step for imparting a bent line of either a mountain fold or a valley fold along the bend of the bent edge to the bent edge;
Next, there is a three-dimensional molding step of three-dimensionalizing the bent edge with the bent line as a starting point by moving the blank portions on both ends of the bent edge so that the interval between the ends is narrowed or widened. The manufacturing method of the metal component with a solid edge characterized by the above-mentioned.
(2) The three-dimensionally edged metal according to (1), wherein in the bent shape imparting step, a blank portion adjacent to the bent edge portion is provided with a bent line having a mountain and a valley opposite to the bent line. A manufacturing method for parts.
(3) The method for manufacturing a metal part with a three-dimensional edge according to (1) or (2), further including a crease step of making a crease line on a portion where the fold line is to be provided before the fold shape provision step.
(4) In the method for manufacturing a metal part with a solid edge according to any one of (1) to (3), as the blank, a blank having end plate portions on both end sides of the blank is used. The manufacturing method of the metal component with a three-dimensional edge characterized by including the clamping part at the time of moving the blank site | part of the both ends side of the said bending edge part, and the intermediate part connected to the both ends of the main-body part in this blank from this clamping part.
(5) In the manufacturing method of the solid-edged metal part according to any one of (1) to (3), as the blank, an end plate part separated in a length direction at an edge part on the opposite side of the bent edge part The manufacturing method of the metal component with a three-dimensional edge characterized by using the thing which has this, and making the said end plate part into the clamping part at the time of moving the said bending edge part.

  According to the present invention, the work material (material) is bent and deformed with little deformation of the drawing, overhanging, and extension flange, so that the bent edge is broken, and the three-dimensional shape is formed into a vertical wall or a chevron without wrinkles. It is possible to form a metal part with a three-dimensional edge even from a single sheet of high-strength steel sheet. Further, since the molding can be performed with almost no expansion and contraction, the three-dimensional molding can be performed even on a bent edge portion having a small radius of curvature R, which has been impossible in the conventional three-dimensional molding.

It is a top view which shows embodiment example (1) of this invention. It is a three-dimensional view showing a part to be manufactured according to an embodiment (1). It is a top view which shows example embodiment (2) of this invention. It is a three-dimensional view showing a part to be manufactured according to Embodiment (2). It is a top view which shows example embodiment (3) of this invention. It is a three-dimensional view showing a part to be manufactured according to an embodiment (3). It is a top view which shows example embodiment (4) of this invention. It is a three-dimensional view showing a part to be manufactured according to Embodiment (4). It is a top view which shows example embodiment (5) of this invention. It is a three-dimensional view showing a part to be manufactured according to Embodiment (5). It is a top view which shows example embodiment (6) of this invention. It is a three-dimensional view showing a part to be manufactured according to Embodiment (6). It is the top view (a) and sectional drawing (b) which show the example of a crease line.

  The present invention uses, as a material, a blank cut out from a metal plate and having curved curved edges with both ends, and the curved edges or a blank portion adjacent to the curved edges is further solid (vertical wall, mountain shape, or one of these) Is a method of manufacturing a metal part with a three-dimensional edge by forming a metal part with a three-dimensional edge by forming a metal part with a three-dimensional edge, and as a manufacturing process thereof, the bent part is bent along the bend of the bent edge. Alternatively, a folding line forming step is provided in which a bent line with either a valley or a valley is provided, or a blank line adjacent to the bent edge is provided with a bent line having a peak and a valley opposite to the bent line. Then, by moving the blank portions on both sides of the bent edge so that the distance between the ends is narrowed or widened, the bent edge or further is started from the bent line. And a three-dimensional molding process of three-dimensional blank portions adjacent to the curved rising edge. Here, the curved shape having both ends includes a polygonal line shape having both ends.

  When a bent line is applied in the bent shape applying step, in the next three-dimensional forming step, the bent portions are moved by moving the blank portions on both ends of the bent edge portion so that the distance between the both ends is narrowed or widened. Due to the difference in line length between the two sides with the shape line as a boundary, one of these two sides naturally rises or sinks with respect to the other, and therefore the bent edge or further adjacent to the bent edge starting from the bent line. It is possible and easy to make the blank part to be three-dimensional. Without the folding shape imparting step, it is very difficult to make a three-dimensional shape by the three-dimensional molding step.

In addition, it is preferable to give the said bent line so that the fold angle of the mountain fold shape or the valley fold shape which gives this may become an obtuse angle of about 165 degree-175 degree | times. As the means for providing the bent line, press working using a mold having a bent shape is preferable.
Moreover, in this invention, it is preferable to have the crease | folding process which attaches a crease line to the provision part of the said fold line before the said fold form provision process. Thereby, the target shape of a component can be obtained more accurately. As shown in FIG. 13 (a), the crease line 11 applied to the blank 10 may be a solid line, a broken line, a dotted line, or a combination thereof. Further, as shown in FIG. 13B, the crease line 11 may be formed in a V groove (or U groove) shape by coining or the like. At this time, if the depth of the V-groove is too deep, the three-dimensional forming process may cause breakage, so the thickness ratio to the blank plate is preferably 20% or less.

When the blank portions on both ends of the bent edge are moved, the blank 10 is three-dimensionalized according to the amount of movement at both ends, so that the cross-sectional shape of the blank 10 changes during molding and the blank 10 is deformed to rise during molding.
To move the blank part on both ends, it is only necessary to apply a force to both ends of the blank 10 with a jig and push it inward. For example, both ends of the blank 10 may be prevented from jumping forward by the force. It may be possible to push inward while pinching the blank part on the side, and when pinching, the clamping mechanism can be rotated to follow the deformation so that the blank 10 rises during molding It may be. However, since it is complicated to make the holding mechanism rotatable, it is preferable that the holding mechanism is simply held between the upper and lower molds so that the blank 10 can be moved while being kept horizontal. However, if it is moved while keeping it simply horizontal, the portion where the blank 10 is held is prevented from standing up during forming, and a portion where a desired shape cannot be imparted to the solid metal part with a solid edge is generated.

For this reason, as the blank used for the material, a blank having end plate portions on both end sides of the blank is used, and the end plate portion is a holding portion for moving the blank portion on both ends of the bent edge portion, and the main body in the blank from the holding portion. You may make it provide the intermediate part connected to the both ends of a part.
In this case, by placing the intermediate part on the part where the angle with respect to the horizontal continuously changes during molding, the blank part on both ends can be easily moved while the clamping part is kept horizontal. A desired shape can be imparted to the three-dimensional metal part with a three-dimensional edge.

Or as a blank, what has the end plate part isolate | separated to the length direction in the edge part on the opposite side to a bending edge part is good, and it is good also as a clamping part at the time of moving the both ends of a bending edge part.
In this case, the intermediate portion can be omitted, and the end plate portion is separated in the length direction, so that when the both end portions are moved, the end plate portion is located on the outer bending side, which may cause tensile resistance. The blank can be deformed by moving the both ends without causing the occurrence.

In any case, when the clamping is performed by upper and lower molds (not shown), it can be firmly performed by using hydraulic pressure or the like. In addition, any method may be used for fixing or clamping the blank as long as it can be firmly fixed or clamped, such as a method of providing a hole in the end plate portion and fastening it to the lower mold through a bolt.
FIG. 1 shows an embodiment (1) of the present invention, and FIG. In this example, in order to make the bending edge 3 located on the inner bending side of the blank 10 to be the vertical wall edge TK of the part 20, first, a bent line 4 is formed on the opposite edge side boundary of the bending edge 3 by press working. Next, move the blank part on both ends 1 and 2 side of the bent edge 3 in the direction of arrows 30 and 31 so that the distance between the ends 1 and 2 is narrowed. As described above, the bent edge portion 3 is formed into a vertical wall, and a part 20 with a desired vertical wall edge TK is obtained. In FIG. 2, COA is an observation site for occurrence of cracks and SOA is an observation site for occurrence of wrinkles.

  FIG. 3 shows an embodiment (2) of the present invention, and FIG. 4 shows a part to be manufactured. In this example, in order to make the bent edge 3 located on the inner bent side of the blank 10 and the blank part 5 adjacent to the bent edge 3 as the chevron edge YG of the part 20, first, the opposite edge side of the bent edge 3 by pressing. (Arrow A side in FIG. 3) A mountain-shaped line 4 is given to the boundary, and a valley-shaped line 6 is given to the boundary opposite to the curved edge 3 of the blank portion 5, and then both ends 1 of the curved edge 3 , 2 side blank part is moved in the direction of arrows 30 and 31 so that the distance between both ends 1 and 2 is narrowed, and the bent edge 3 and blank are started from the mountain-folded line 4 and valley-shaped line 6 The portion 5 is chevronized to obtain the part 20 with the desired chevron edge YG. In FIG. 4, COA is an observation site for occurrence of cracks and SOA is an observation site for occurrence of wrinkles.

  FIG. 5 shows an embodiment (3) of the present invention, and FIG. In this example, in order to make the bending edge 3 located on the outer bending side of the blank 10 and the blank part 5 adjacent thereto as the chevron edge YG of the part 20, first, the opposite edge side of the bending edge 3 by pressing. (Arrow A side in FIG. 5) A mountain-shaped line 4 is provided at the boundary, and a valley-shaped line 6 is provided at the boundary opposite to the bent edge 3 of the blank portion 5, and then both ends 1 of the bent edge 3 are provided. , 2 side blank part is moved in the direction of arrows 30 and 31 so that the distance between both ends 1 and 2 is narrowed, and the bent edge 3 and blank are started from the mountain-folded line 4 and valley-shaped line 6 The portion 5 is chevronized to obtain the part 20 with the desired chevron edge YG. In FIG. 6, COA is an observation site for occurrence of cracks and SOA is an observation site for occurrence of wrinkles.

FIG. 7 shows an embodiment (4) of the present invention, and FIG. In the present example, the part 20 has a T-shaped planar shape, and has a vertical wall edge TK on both T-shaped arms and a chevron edge YG on the trunk. The blank 10 corresponding to the component 20 has a Y shape in plan view.
Therefore, in the bent shape imparting step, on the opposite edge side (arrow A side in FIG. 7) of the bent edge portion 3 from the upper edge side of both Y-shaped arms and from the lower edge sides of the left and right arms to the side sides of the torso. A mountain-shaped line 4 is given. For the trunk portion, a valley-shaped line 6 is applied to the boundary of the blank portion 5 adjacent to the bent edge portion 3 on the side opposite to the bent edge portion 3 for forming the chevron edge YG.

In addition, in order to prevent cracks and wrinkles at the Y-shaped nodule, the trough fold line 6 is extended to the maximum bend point P of the fold line 4 on the upper edge of both arms, and the ridges on each side A mountain fold line 4 connecting each of the torso boundary points Q1, Q2 of the fold line 4 and the maximum bending point P is added.
Next, in the three-dimensional molding process, the blank parts on both ends 1 and 2 of the bent edge 3 on the upper edge side of both Y-shaped arms are moved in the directions of arrows 30 and 31 so that the distance between both ends 1 and 2 is widened. Thus, a T-shaped part 20 with a desired vertical wall edge TK or a chevron edge YG is obtained. Here, when moving the blank part on the both ends 1 and 2 side of the bending edge 3 as described above, the lower end of the Y-shaped body is fixed in order to obtain a stable movement. Then, both ends 1 and 2 of the bent edge portion 3 on the lower edge side of both arms become a movable end that also serves as one of both ends of the bent edge portion 3 on the left and right sides, respectively, and the fixed end (the body portion described above) Therefore, the bent edge 3 to the blank part 5 on both sides are three-dimensionalized in the same manner as the bent edge 3 on the upper edge side.

FIG. 9 shows an embodiment (5) of the present invention, and FIG. 10 shows a part to be manufactured.
As the blank 10, the one having the end plate portions 7 and 7 on both end sides of the blank 10, the end plate portions 7 and 7 are sandwiched portions 7a when moving the blank portions on both ends 1 and 2 side of the bent edge portion 3 and An intermediate portion 7b connected from the sandwiching portion 7a to both ends 10b of the main body portion 10a in the blank 10 is provided.
A part 20 with a desired vertical wall edge TK is fixed by holding the holding part 7a with upper and lower molds (not shown) or the like and moving it in the directions of arrows 30 and 31 so that the distance between both ends 1 and 2 is narrowed. Get. By applying the intermediate part 7b to the part where the angle with respect to the horizontal continuously changes during molding from the sandwiching part 7a to the main body part 10a, the sandwiching part 7a can easily move the blank part on both end sides while keeping it horizontal. Thus, a desired shape can be imparted to the metal part with a solid edge after molding.

FIG. 11 shows an embodiment (6) of the present invention, and FIG.
As the blank 10, a blank 10 having end plate portions 7 and 7 separated in the length direction B at the edge opposite to the bent edge portion 3 of the blank 10 is used, and the bent edge portion 3 is moved by the end plate portions 7 and 7. It is a pinching part. The end plate portions 7 and 7 are formed in a V groove (or U) by coining or the like in the blank 10 along the planned crease line 8 in the folding process according to the shape of the part to be manufactured (metal part with a solid edge). Grooves) or a blank 10 may be formed by bending along the crease line 8 instead.

  After the creasing process, the end plate portions 7 and 7 are fixed by being sandwiched by upper and lower molds (not shown), and moved in the directions of the arrows 30 and 31 so that the distance between the ends 1 and 2 is reduced. A part 20 with a vertical wall edge TK is obtained.

Example 1
A blank cut out from a steel plate having mechanical properties shown in Table 1 was used as a raw material, and a metal part with a solid edge was manufactured by the forming method shown in Table 2, and the resulting part was cracked to determine whether wrinkles were generated. Here, in the example of the present invention, the fold angle of the mountain fold line and the valley fold line was 90 degrees. In Comparative Examples Nos. 1, 8, and 15, the parts to be manufactured were the same as those in Invention Examples Nos. 2, 10, and 18, respectively. The presence / absence of cracking was determined by visual observation of the observation site COA in FIGS. 2, 4, 6, 8, 10, and 12, and the presence / absence of wrinkle generation was determined by visual observation of the observation site SOA. The results are shown in Table 2.

According to Table 2, when manufacturing a metal part with a three-dimensional edge by three-dimensionally forming the bent edge of a blank made of a high-strength steel plate, conventional press forming has caused wrinkles, but in the present invention, wrinkles and wrinkles have been generated. The desired part could be manufactured without generating it.
(Example 2)
A blank cut out from a steel sheet having mechanical properties shown in Table 1 is used as a raw material, and a V-groove is formed as a crease in the above-described crease process under the conditions shown in Table 3, and then a solid edged metal part is formed by the forming method shown in Table 3. In comparison with Example 1 (comparison between the same materials and molding methods), the presence or absence of wrinkles is determined and the degree of coincidence with the target shape is visually observed. When the degree of coincidence with the target shape is even better, the shape evaluation is evaluated as ◯. Here, the fold angle of the mountain fold line and the valley fold line was 90 degrees as in the first embodiment. The presence / absence of cracking was determined by visual observation of the observation site COA in FIGS. 2, 4, 6, 8, 10, and 12, and the presence / absence of wrinkle generation was determined by visual observation of the observation site SOA. The results are shown in Table 3. In addition, the depth (%) of the V groove in Table 3 is the ratio of the depth of the V groove to the blank plate thickness.

  As shown in Table 3, there was no occurrence of cracks and wrinkles, and a solid edged metal part having a better match with the target shape than the case of Example 1 (shape evaluation was ◯) could be produced.

1,2 Both ends of the bent edge
3 Bent edge
4 Mountain folded wire
5 Blank part adjacent to the curved edge
6 Valley-fold line
7 End plate
7a Clamping part
7b Middle part
8 Scheduled fold line
10 blank
10a Body part in blank
10b Both ends of body part in blank
11 Fold line
20 parts (metal parts with solid edges)
30,31 Arrow indicating the direction to move the blank part
TK vertical wall edge
YG Yamagata edge A Opposite side B Length direction

Claims (5)

A blank cut out from a metal plate and having curved curved edges with both ends is used as a material, and the bent edge or further the blank part adjacent to the curved edge is formed in three dimensions to obtain a solid edged metal part. A method of manufacturing a metal part with a solid edge,
A bent shape imparting step for imparting a bent line of either a mountain fold or a valley fold along the bend of the bent edge to the bent edge;
Next, there is a three-dimensional molding step of three-dimensionalizing the bent edge with the bent line as a starting point by moving the blank portions on both ends of the bent edge so that the interval between the ends is narrowed or widened. The manufacturing method of the metal component with a solid edge characterized by the above-mentioned.   The manufacturing method of the metal component with a three-dimensional edge of Claim 1 which provides the folding line which a mountain and a valley are reverse to the said folding line to the blank part adjacent to the said bending edge part in the said bending form provision process further. .   The manufacturing method of the metal component with a three-dimensional edge of Claim 1 or 2 which has a crease process which attaches a crease line to the provision part of the said fold line before the said fold form provision process.   In the manufacturing method of the metal component with a solid edge in any one of Claims 1-3, what has an end plate part on the both ends of this blank is used as the said blank, The said end plate part is the said bending edge part. The manufacturing method of the metal component with a three-dimensional edge provided with the clamping part at the time of moving the blank site | part of a both-ends side, and the intermediate part connected to the both ends of the main-body part in this blank from this clamping part.   In the manufacturing method of the metal component with a solid edge in any one of Claims 1-3, what has an end plate part separated in the length direction in the edge part on the opposite side of the above-mentioned bending edge part as the above-mentioned blank, The manufacturing method of the metal component with a three-dimensional edge characterized by using the said end plate part as a clamping part at the time of moving the said bending edge part.

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