JP6022364B2 - Mold for manufacturing metal parts with solid edges - Google Patents

Description

  The present invention relates to a metal mold for manufacturing a metal part with a three-dimensional edge, and more specifically, for manufacturing a metal part with a three-dimensional edge by press molding, and a metal plate (for example, a high tensile strength (TS) of 590 MPa or more. The present invention relates to a metal mold for manufacturing a metal part with a three-dimensional edge, which is used to form a three-dimensional edged metal part by forming a curved edge part provided on a blank of a high-strength steel plate or a blank part adjacent to the curved edge part.

  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 of obtaining a metal part with a three-dimensional shape, for example, a vertical wall, at the bent edge, press forming (hereinafter referred to as conventional press forming) in which various forms of bending, drawing, and stretch flange are combined with a single metal plate is performed. In addition, as a method for obtaining dimensional accuracy, a method of providing a divergent step in the vertical wall portion (Patent Document 1) and a method of forming the flange portion in two stages (Patent Document 2) have been proposed and twisted. As a method for preventing 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, especially when the blank is a high-strength steel plate, when a solid metal part with a three-dimensional bent edge is manufactured with a conventional press mold, it is a simple process and wrinkles occur, resulting in a three-dimensional metal part with a solid edge. Therefore, there is a problem that it is extremely difficult to achieve both process simplification and product weight reduction.

  The inventors of the present invention have studied means for solving the above problems, and have 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 a blank part adjacent to the bent edge part into a three-dimensional shape A metal mold for manufacturing a metal part with a three-dimensional edge used for manufacturing a fold, and a bent line that gives either a fold or a valley fold along the bend of the bent edge is provided to the bent edge. The first-step mold used in the shape line applying step, and then the central portion between both ends of the bent edge portion is pushed and moved so that the interval between the both ends is narrowed, whereby the bent edge portion starts from the bent line. Alternatively, a metal mold for producing a metal part with a three-dimensional edge, further comprising a second-step metal mold used in a three-dimensional molding process for three-dimensionalizing a blank portion adjacent to the bent edge part.
(2) The manufacturing of the metal part with a three-dimensional edge according to (1), wherein the bent line to be applied using the first-step mold is a bent line having a bending radius of 0.5 mm to 30 mm. Mold.
(3) The first-step mold includes a flat clamping portion, and both ends or a middle of a portion to which at least one bent line is provided from one or a plurality of blank body portions from the clamping portion. The metal mold for manufacturing a metal part with a three-dimensional edge according to (1) or (2), wherein an intermediate part connected to the part is provided to the blank.
(4) The bent line is a plurality of curves, and a part of at least one of the plurality of curves has a larger curvature than a curved part connected to both sides of the part. The metal mold | die for manufacture of the metal component with a solid edge as described in any one of (1)-(3).
(5) Any one of the above (1) to (4), wherein the second step mold is configured to hold a periphery of a bent line that is a starting point at which the bent edge portion becomes three-dimensional. Mold for manufacturing metal parts with three-dimensional edges described in 1.
(6) Any one of said (1)-(5) characterized by the said 2nd process metal mold | die being the structure which hold | suppresses the vertical wall part which is a site | part adjacent to the said bending | flexion edge part to make three-dimensional. Mold for manufacturing metal parts with three-dimensional edges described in 1.
(7) The metal mold with a three-dimensional edge according to any one of (1) to (6), wherein the second process die is configured to suppress the three-dimensionalization of the bent line. Production mold.

  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 mountain shape 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 the schematic which shows embodiment example (1) of this invention. It is the schematic which shows embodiment example (2) of this invention. It is the schematic which shows embodiment example (3) of this invention. It is the schematic which shows embodiment example (4) of this invention. It is the schematic which shows embodiment example (5) of this invention. It is the schematic which shows embodiment example (6) of this invention. It is the schematic which shows embodiment example (7) of this invention.

The present invention uses, as a material, a blank cut out from a metal plate and having curved curved edges having both ends, and the bent edge or further a blank portion adjacent to the bent edge is formed into a three-dimensional shape to form a metal with a solid edge It is a metal mold for manufacturing a metal part with a three-dimensional edge used when manufacturing a part.
The manufacturing mold is a first-step mold used in a bent line applying process in which a bent line of either a mountain fold or a valley fold along the bent edge is bent on the bent edge. By pushing the center part between both ends of the bent edge and moving the distance between the ends so as to be narrowed, the bent edge or the blank part adjacent to the bent edge from the bent line is solidified. And a second-step mold used in the three-dimensional molding step to be converted [the present invention (1)]. Here, the curve having both ends includes a broken line having both ends.

  When a bent line is applied in the bent line applying step, the bent shape is formed by pressing a central portion between both ends of the bent edge in the three-dimensional forming step, which is the next step, so that the distance between the ends is reduced. Due to the difference in line length between the two sides with the line as a boundary, one of these two sides naturally rises or sinks with respect to the other, and is therefore adjacent to the bent edge or further to the bent edge starting from the bent line. It is possible and easy to make the blank part three-dimensional. Three-dimensionalization by the three-dimensional molding process is extremely difficult without the bent line applying process.

  In addition, as long as the 1st process die used for the above-mentioned bent line giving process can give a bent line to a blank, roll forming, sequential forming, liquid pressure forming, rubber forming, foam forming, draw forming, A mold used for any molding such as stretch molding may be used. However, considering the positional accuracy and production efficiency of the bent line, a press working mold having a mold shape corresponding to the bent shape is preferable.

  Further, the shape of the bent line is preferably a bending radius of 0.5 mm or more and 30 mm or less [present invention (2)]. Since a high-strength steel plate is inferior in bending workability to mild steel, if the bending radius of the bent wire is less than 0.5 mm, cracks may occur in the bent portion. On the other hand, when it exceeds 30 mm, it is difficult to become a starting point for three-dimensionalization in the three-dimensional molding process. In addition, in order to make a three-dimensional shaping | molding process more efficient and to prevent the crack in a bending part more effectively, it is preferable that it is a bending radius 1 mm or more and 10 mm or less.

  In contrast to the first-step molded product (molded product that has undergone the above-mentioned broken line applying step), the second-step mold is configured to push the central portion between both ends of the bent edge portion and move so that the interval between the both ends is narrowed. The Such a configuration has a mechanism for applying a force to the central portion with a jig and thereby raising the bent edge while rotating the both ends. In the conventional press molding, if it is attempted to raise the bent edge, the wire length of the material is insufficient at the contact portion with the jig, causing stretched flange cracking. On the other hand, in this invention, the line length of the material which is insufficient can be compensated by rotating the both ends of a bending edge centering on the position used as the starting point of three-dimensionalization. In addition, in order to hold | maintain a 1st process molded product here, it is preferable to hold | suppress the circumference | surroundings of the bent line used as the starting point from which a bending edge part becomes three-dimensional [this invention (5)].

  The mechanism of the second-step mold that moves the bent edge of the first-step molded product changes the direction of the above-mentioned vertical movement in addition to the mechanism that directly conveys the vertical movement of the slide of the press machine through a jig such as a punch. As a method to be used, a mechanism using an inclined surface represented by a cam mechanism, a link mechanism, or a mechanism using a lever may be used. In addition to the driving force of the press machine, a cylinder using electricity, air pressure, or hydraulic pressure may be used.

  In order to perform molding more stably, a mechanism for moving both ends or one end while sandwiching both ends so that the first-step molded product does not jump out of the second-step mold is preferable. In the case of clamping, it is preferable to simply hold it with upper and lower molds or the like so that the holding part of the first-step molded product can be moved while being kept horizontal. However, if it is moved while keeping it simply horizontal, the sandwiched portion is prevented from standing up during molding, and a portion where the desired three-dimensional edged metal part shape cannot be given to the first-step molded product is generated.

  Therefore, the first-step mold is formed between the flat clamping portion, and both ends or middle portions of the portion to which at least one bent line is provided from one or a plurality of the blank main body portions from the clamping portion. It is preferable that the intermediate part to be connected is provided to the blank [present invention (3)]. By applying the intermediate portion to a portion where the angle with respect to the horizontal continuously changes during molding, the both ends can be easily moved while the holding portion is kept horizontal.

  In the three-dimensional molding process, if there is a part that deforms more easily than the three-dimensional molding of the first process is made three-dimensional from the bent line, that part is preferentially deformed. In order to prevent molding defects such as buckling of a bent line, it is effective to preferentially three-dimensionalize the bent edge of the first-step molded product, which is likely to be cracked or wrinkled. For this purpose, the bent line is formed into a plurality of curves around the bent edge portion to be preferentially three-dimensionalized, and at least one of the plurality of curves is connected to both sides of the part. It is preferable that the curvature be larger than that of the curved portion [present invention (4)]. When the curvature of the bent line is increased, the difference in line length between both sides with the bent line as a boundary increases with respect to the movement amount of both ends of the bent edge. For this reason, the bent edge is easily three-dimensionalized.

  On the other hand, when the three-dimensionalization of the bent edge is localized, the three-dimensionalization of the other bent edge may be insufficient. As a countermeasure, it is effective to configure the second-step mold so as to hold down the vertical wall portion, which is a portion adjacent to the bent edge to be locally three-dimensionalized while the bent edge is three-dimensionalized [ Invention (6)]. If you hold down the bend edge that you want to make into a three-dimensional shape, you will be forced to make the surroundings three-dimensional. Therefore, a wide range can be made three-dimensionally by using a second-step mold having a configuration in which a pressing jig is arranged at a required place.

  If the bent line and the bent edge of the first process molded product or the distance between the bent lines are not equal, in the second process mold, it will be bent with the above starting point as the apex along with the three-dimensional bending edge. The shape line tries to be three-dimensional in a bow shape when seen from the horizontal plane. At this time, if the bent line is pressed, the deformation of the first-step molded product is dispersed to other positions, so that the bent line can be prevented from being three-dimensional in a bow shape [present invention (7)]. . The pressing position is preferably only around the apex of the bow, and the pressing method may be any method such as placing a metal plate near the folded line. Further, if the three-dimensional shape of the bent line is excessively advanced, the bent line may be buckled in the vicinity of the starting point, which also has an effect of preventing buckling. Furthermore, since the buckling can be prevented, the first-step molded product portions on both ends of the bent edge can be moved more smoothly, and the bent edge can be more effectively three-dimensionalized.

  FIG. 1 is a schematic diagram showing an embodiment (1) of the present invention. In this example, a structure of a first-step mold for manufacturing a member having a V-shaped cross section by giving a mountain fold line (mountain fold line) 110 to the blank 10 is shown. This first-step mold has a die 1 and a punch 2 having a mold cross-sectional shape corresponding to the V-shaped cross section of the product. Reference numeral 15 denotes a bent edge, and 16 denotes an end of the bent edge. SOA and COA are observation sites for the occurrence of wrinkles and observation sites for occurrence of cracks in the product manufactured from the blank 10 (the same applies hereinafter).

  FIG. 2 is a schematic view showing an embodiment (2) of the present invention. In this example, by adding a mountain fold line 111 and a valley fold line (valley fold line) 120 to the blank 10 in the embodiment example (1), the intermediate part 6 and the sandwiching part 5 (the bent edge in FIG. 1) A structure of a first-step mold having a configuration in which (corresponding to the end 16) is given is shown. In addition, the same code | symbol is attached | subjected to the part same as an above-mentioned figure, or an equivalent part, and description is abbreviate | omitted.

FIG. 3 is a schematic view showing an embodiment (3) of the present invention. In this example, in order to manufacture a member having an M-shaped cross section, the intermediate portion 6 and the sandwiching portion 5 are provided by adding the mountain fold lines 111 and 112 and the valley fold lines 121 and 122 in the embodiment example (1). The structure of the 1st process metal mold | die made into the structure is shown. In addition, the same code | symbol is attached | subjected to the part same as an above-mentioned figure, or an equivalent part, and description is abbreviate | omitted.
FIG. 4 is a schematic view showing an embodiment (4) of the present invention. In this example, in the embodiment example (3), instead of the mountain fold line 111 and the valley fold line 121, the first process when the mountain fold line 113 and the valley fold line 123 each have a portion 50 having a larger curvature than the other part is used. The structure of the mold is shown. In addition, the same code | symbol is attached | subjected to the part same as an above-mentioned figure, or an equivalent part, and description is abbreviate | omitted.

  FIG. 5 is a schematic view showing an embodiment (5) of the present invention. In this example, the structure of the second step mold is shown. In this example, the punch 23 that is brought into contact with the central portion of the bent edge portion 15 of the first-step molded product 11 is urged by the cam slider 24 and the cam driver 25, and a push 30 is added to the central portion to rotate the both ends. 31 to reduce the distance between the two ends. Further, in order to restrain the troubled vertical movement of the molded product 11 in the first process, the non-curved edge portion adjacent to the central portion pushed by the punch 23 with the mountain line 110 interposed therebetween is defined as the held portion 32. The part was held by plate pressing pads (lower and upper) 21 and 22 so that only horizontal sliding was possible. The punch 23, cam slider 24, cam driver 25, and plate pressing pads (lower and upper) 21 and 22 are all supported by the holder 20.

FIG. 6 is a schematic view showing an embodiment (6) of the present invention. In this example, the case where the second-step mold includes a pressing jig 40 that presses the bent edge that is locally three-dimensionalized at the rising edge 41 of the bent edge is shown. In addition, the same code | symbol is attached | subjected to the part same as an above-mentioned figure, or an equivalent part, and description is abbreviate | omitted.
FIG. 7 is a schematic view showing an embodiment (7) of the present invention. In this example, a case is shown in which the second step mold includes a pressing block 42 that presses the arcuate rise 43 of the mountain fold line 110 that is three-dimensionally shaped like a bow. In addition, the same code | symbol is attached | subjected to the part same as an above-mentioned figure, or an equivalent part, and description is abbreviate | omitted.

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.
Further, the degree of coincidence with the target shape was visually observed, and Example No. If the degree of coincidence with the target shape is equivalent to that of 5, the shape evaluation was evaluated as ◎.

Here, in the example of the present invention, the fold angle of the mountain fold line and the valley fold line was 90 degrees. Comparative Example No. In 1-4, the parts to be manufactured were the same as those of the embodiment examples (1) to (4) of the present invention. The presence or absence of cracking was determined by visually observing the observation site COA in FIGS. 1 to 4, and the presence or absence of wrinkling 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.

  Furthermore, by using the embodiment examples (6) to (7) in combination, it was possible to manufacture a solid-edged metal part having a better match with the target shape (shape evaluation is ◎).

DESCRIPTION OF SYMBOLS 1 Die 2 Punch 5 Clamping part 6 Intermediate part 10 Blank 11 1st process molded product 12 Molded product 15 after the 2nd process or in the middle 15 Bend edge 16 Bend edge end 20 Holder 21 Plate pressing pad (lower)
22 Board holding pad (top)
23 Punch 24 Cam slider 25 Cam driver 30 Push-in 31 Rotation 32 Holding part 40 Holding jig 41 Bending edge rise 42 Holding block 43 Arc-like rising 50 Parts 110, 111, 112, 113 having a larger curvature than other parts Mountain line 120, 121, 122, 123 Valley line

Claims (7)

  A blank having a curved bent edge with both ends cut out from a metal plate is used as a material, and the bent edge or a blank part adjacent to the bent edge is formed in a three-dimensional shape to produce a metal part with a three-dimensional edge. A metal mold for manufacturing a metal part with a three-dimensional edge used in the case, wherein a bent line is applied to the bent edge to give a bent line of either a mountain or a valley along the bent edge The first step mold used in the process and then the central part between the both ends of the bent edge is pushed and moved so that the distance between the two ends is narrowed, whereby the bent edge or further the A metal mold for manufacturing a metal part with a three-dimensional edge, comprising: a second-step metal mold used in a three-dimensional molding process for three-dimensionalizing a blank portion adjacent to a bent edge part.   2. The mold for manufacturing a metal part with a three-dimensional edge according to claim 1, wherein the bent line provided using the first-step mold is a bent line having a bending radius of 0.5 mm to 30 mm.   The first-step mold is connected to both ends or a middle portion of a flat clamping portion and a portion to which at least one bent line is provided from one or a plurality of blank body portions from the clamping portion. The metal mold for manufacturing a metal part with a three-dimensional edge according to claim 1 or 2, wherein an intermediate part is applied to the blank.   The bent line is a plurality of curves, and a part of at least one of the plurality of curves has a larger curvature than a curved part connected to both sides of the part. 3. A mold for manufacturing a metal part with a solid edge according to any one of 3.   The said 2nd process metal mold | die was set as the structure which hold | suppresses the periphery of the bent line used as the starting point from which the said bending edge becomes three-dimensional, The solid edge with any one of Claims 1-4 characterized by the above-mentioned. Mold for manufacturing metal parts.   The said 2nd process metal mold | die was set as the structure which hold | suppresses the vertical wall part which is a site | part adjacent to the said bending | flexion edge part to make three-dimensional, The solid edge with any one of Claims 1-5 characterized by the above-mentioned. Mold for manufacturing metal parts.   The said 2nd process metal mold | die was set as the structure which hold | suppresses the three-dimensionalization of the said bent line, The metal mold for manufacture of the metal component with a solid edge as described in any one of Claims 1-6 characterized by the above-mentioned.

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