JP2005088051A

JP2005088051A - Press die

Info

Publication number: JP2005088051A
Application number: JP2003325424A
Authority: JP
Inventors: Kazuyuki Taniguchi; 和行谷口; Masami Yamanaka; 万三三山中; Torao Shibuya; 虎男渋谷
Original assignee: Toyota Auto Body Co Ltd
Current assignee: Toyota Auto Body Co Ltd
Priority date: 2003-09-18
Filing date: 2003-09-18
Publication date: 2005-04-07

Abstract

PROBLEM TO BE SOLVED: To prevent defective shaping due to springback without necessitating complicated adjusting work. SOLUTION: A press die for bending a flat steel plate P, which is equipped with a punch 2, a pad 3 and bending blades 5A and 5B. The punch 2 on which the steel plate P is placed is mounted on a lower die 1. The pad 3 mounted on an upper die 4 sandwiches the steel plate P with the punch 2. The bending blades 5A and 5B mounted on the upper die 4 descend with the descent of the upper die 4 and depress edge portions of the steel plate P so as to bend the steel plate P. Just before the finish of the bending of the steel plate P, the bending blades 5A and 5B move obliquely upward toward the punch 2 so as to render compressive force in the direction of pushing up the edges of the steel plate P. COPYRIGHT: (C)2005,JPO&NCIPI

Description

本発明はプレス型に関し、特にスプリングバックによる成形不良を防止できるプレス型に関する。 The present invention relates to a press die, and more particularly, to a press die that can prevent molding defects due to springback.

近年、車両軽量化等の要請からハイテンション鋼板が多用されているが、このような鋼板は曲げ成形時の残留応力が大きいためにスプリングバックによる成形不良を生じ易い。例えば図１５に示すようなパンチ８１の外周に沿って、ダイ８２によって鋼板Ｐを平行な側壁Ｐ１，Ｐ２を有する逆Ｕ字形に成形しても、スプリングバックにより図１６の矢印で示すように上記側壁Ｐ１，Ｐ２が外方へ開いて成形不良となる。そこで、例えば特許文献１では、上型とこれに設けたパッド、および下型とこれに設けたクッションとで鋼板を挟持して、鋼板に座屈を生じることなく圧縮力を付与して残留応力を除去することにより成形不良を防止したプレス型が示されている。
特開２００２−１７２４２３ In recent years, high-tension steel plates have been widely used due to demands for weight reduction of vehicles and the like. However, since such steel plates have a large residual stress at the time of bending, they are liable to cause forming failure due to springback. For example, even if the steel plate P is formed into an inverted U shape having parallel side walls P1 and P2 along the outer periphery of the punch 81 as shown in FIG. The side walls P1 and P2 open outwardly, resulting in molding failure. Therefore, for example, in Patent Document 1, a steel plate is sandwiched between an upper die, a pad provided on the upper die, and a lower die and a cushion provided on the upper die, and a compressive force is applied to the steel plate without causing buckling, thereby residual stress. A press die is shown in which molding defects are prevented by removing.
JP2002-172423

しかし、上記従来のプレス型で鋼板の成形をしようとすると、バネ等の反力発生手段を介して上型にパッドを設ける一方、下型のポンチに反力発生手段を介してクッションと、さらに反力発生手段を介してクッションリングを設ける必要があって、複数の反力発生手段を適正な反力に設定する等の調整作業に手間取るという問題があった。 However, when trying to form a steel sheet with the above conventional press die, a pad is provided on the upper die via a reaction force generating means such as a spring, while a cushion is provided on the lower punch via the reaction force generating means, There is a problem that it is necessary to provide a cushion ring via the reaction force generating means, and it takes time for adjustment work such as setting a plurality of reaction force generating means to appropriate reaction forces.

そこで本発明はこのような課題を解決するもので、煩雑な調整作業を要することなくスプリングバックによる成形不良を防止できるプレス型を提供することを目的とする。 SUMMARY OF THE INVENTION The present invention solves such problems, and an object of the present invention is to provide a press die that can prevent molding defects due to springback without requiring complicated adjustment work.

上記目的を達成するために、本発明は、平板状の鋼板（Ｐ）を曲げ加工するためのプレス型であって、下型（１）に設けられ、鋼板（Ｐ）が載置されるパンチ（２）と、上型（４）に設けられ、パンチ（２）とにより鋼板（Ｐ）を挟持するパッド（３）と、上型（４）に設けられ、上型（４）の下降により下降し、鋼板（Ｐ）の端部を押し下げることにより曲げ加工を行い、かつ、該曲げ加工が完了する直前にパンチ（２）に向かって斜め上方に移動することにより、鋼板（Ｐ）にその端部を押し上げる方向の圧縮力を付与する曲げ刃（５Ａ，５Ｂ）と、を備えている。ここで、上記下型（１）に設けられ、上型（４）の下降による曲げ刃（５Ａ，５Ｂ）の下降により、曲げ刃（５Ａ，５Ｂ）のパンチ（２）と対向する面（５２）と反対側の斜面（５３）に当接し、曲げ刃（５Ａ，５Ｂ）がその下降に伴いパンチ（２）に向かって移動するように押圧する第１カムドライバー（６Ａ，６Ｂ）と、上型（４）に設けられ、上型（４）の下降により下降し、第１カムドライバー（６Ａ，６Ｂ）が曲げ刃（５Ａ，５Ｂ）に向かって移動するようにその下部斜面（７１）が第１カムドライバー（６Ａ，６Ｂ）の上部斜面（６２）を押圧する第２カムドライバー（７Ａ，７Ｂ）と、を備え、曲げ刃（５Ａ，５Ｂ）にはパンチ（２）と対向する面（５２）の下端に鋼板（Ｐ）の端部を係止する突起（５７）が設けられて、曲げ刃（５Ａ，５Ｂ）は、突起（５７）によって鋼板（Ｐ）の端部を係止しつつ第２カムドライバー（７Ａ，７Ｂ）の押圧による第１カムドライバー（６Ａ，６Ｂ）の移動に伴って斜め上方に移動させられる構造とすることができる。 In order to achieve the above object, the present invention is a press die for bending a flat steel plate (P), which is provided in the lower die (1) and on which the steel plate (P) is placed. (2) is provided on the upper die (4), and the punch (2) sandwiches the steel plate (P). The upper die (4) is provided on the pad (3) and the upper die (4) is lowered. The steel sheet (P) is bent and moved downward by pushing down the end of the steel sheet (P), and is moved obliquely upward toward the punch (2) immediately before the bending process is completed. Bending blades (5A, 5B) for applying a compressive force in the direction of pushing up the end. Here, the surface (52) facing the punch (2) of the bending blade (5A, 5B) provided by the lower die (1) and descending of the bending blade (5A, 5B) by the lowering of the upper die (4). A first cam driver (6A, 6B) that abuts against the slope (53) on the side opposite to the upper surface and presses the bending blade (5A, 5B) so as to move toward the punch (2) as it descends; The lower slope (71) is provided on the mold (4) and descends as the upper mold (4) descends so that the first cam driver (6A, 6B) moves toward the bending blade (5A, 5B). A second cam driver (7A, 7B) for pressing the upper slope (62) of the first cam driver (6A, 6B), and the bending blade (5A, 5B) facing the punch (2) ( 52) is provided with a protrusion (57) for locking the end of the steel plate (P) at the lower end thereof. The blades (5A, 5B) are engaged with the movement of the first cam driver (6A, 6B) by the pressing of the second cam driver (7A, 7B) while the end of the steel plate (P) is locked by the protrusion (57). Thus, the structure can be moved obliquely upward.

本発明においては、曲げ刃が上型の下降により下降して鋼板の端部を押し下げることにより鋼板の曲げ加工が行われ、この曲げ加工が完了する直前に曲げ刃がパンチに向かって斜め上方に移動して鋼板の端部を押し上げる方向で圧縮力を鋼板に付与する。これにより鋼板の残留応力が除去され、この除去された状態で鋼板が曲げ加工される。したがって、成形された鋼板には残留応力が残存せず、スプリングバックにより成形形状が変化して成形不良を生じることはない。 In the present invention, the bending blade is lowered by the lowering of the upper die and pushes down the end of the steel plate to bend the steel plate. Just before the bending is completed, the bending blade is obliquely upward toward the punch. A compressive force is applied to the steel sheet in the direction of moving and pushing up the end of the steel sheet. Thereby, the residual stress of the steel plate is removed, and the steel plate is bent in this removed state. Therefore, residual stress does not remain in the formed steel sheet, and the forming shape does not change due to the springback, so that a forming defect does not occur.

なお、上記カッコ内の符号は、後述する実施形態に記載の具体的手段との対応関係を示すものである。 In addition, the code | symbol in the said parenthesis shows the correspondence with the specific means as described in embodiment mentioned later.

以上のように、本発明のプレス型によれば、従来のように複数の反力発生手段を設ける必要がないから、煩雑な調整作業を要することなく、スプリングバックによる鋼板の成形不良を防止することができる。 As described above, according to the press die of the present invention, since it is not necessary to provide a plurality of reaction force generating means as in the prior art, it is possible to prevent defective formation of the steel sheet due to springback without requiring complicated adjustment work. be able to.

図１にプレス型の垂直断面図を示す。図１において、下型１には型面の中央に上方へ突出させてパンチ２が形成されている。パンチ２は下端部２１を除く本体部２２が上方へ向けてやや拡幅する台形断面をなし、パンチ本体部２２と下端部２１の境界には段付きのコーナ部２３が形成されている。鋼板Ｐはパンチ本体部２２の平らな頂面上に中央を一致させて載置され、鋼板Ｐの中央上部にはパンチ本体部２２の頂面とほぼ同幅のパッド３が位置している。パッド３は上型４の型面との間に配設されたバネ体３１によって下方へ付勢されて鋼板Ｐの上面に押しつけられている。なお、パンチ本体部２２の断面外周長は鋼板Ｐの板幅とほぼ等しくしてある。 FIG. 1 shows a vertical sectional view of the press die. In FIG. 1, a punch 2 is formed on the lower die 1 so as to protrude upward in the center of the die surface. The punch 2 has a trapezoidal cross section in which the main body portion 22 except the lower end portion 21 is slightly widened upward, and a stepped corner portion 23 is formed at the boundary between the punch main body portion 22 and the lower end portion 21. The steel plate P is placed on the flat top surface of the punch main body portion 22 so that the centers thereof coincide with each other, and the pad 3 having the same width as that of the top surface of the punch main body portion 22 is located at the center upper portion of the steel plate P. The pad 3 is urged downward by a spring body 31 disposed between the upper die 4 and the upper die 4 and pressed against the upper surface of the steel plate P. The outer peripheral length of the cross section of the punch main body 22 is substantially equal to the plate width of the steel plate P.

パンチ２を挟んで両側に対称形に曲げ刃５Ａ，５Ｂが配設されている。曲げ刃５Ａ，５Ｂは下方へ向けて次第に狭幅となる断面形状をなし、曲げ刃５Ａ，５Ｂの下端面５１は水平面となっている。また、曲げ刃５Ａ，５Ｂの内側面５２はパンチ本体部２２の側面２２１に平行な斜面となり、外側面５３は後述するカムドライバー６Ａ，６Ｂの内側面６１に平行な斜面となっている。曲げ刃５Ａ，５Ｂの下端にはパンチ２が位置する内方へ水平に突出する突起５７が形成されて、これら突起５７の下面が鋼板Ｐの両端上面にそれぞれ当接している。 Bending blades 5A and 5B are arranged symmetrically on both sides of the punch 2. The bending blades 5A and 5B have a cross-sectional shape that becomes gradually narrower downward, and the lower end surfaces 51 of the bending blades 5A and 5B are horizontal surfaces. Further, the inner side surface 52 of the bending blades 5A and 5B is a slope parallel to the side surface 221 of the punch main body 22, and the outer side surface 53 is a slope parallel to the inner side surface 61 of the cam drivers 6A and 6B described later. At the lower ends of the bending blades 5A and 5B, protrusions 57 are formed that protrude horizontally inward where the punch 2 is located, and the lower surfaces of these protrusions 57 are in contact with the upper surfaces of both ends of the steel plate P, respectively.

曲げ刃５Ａ，５Ｂは、上型４の型面の左右位置に下方へ突出させて設けたカムドライバー７Ａ，７Ｂに保持されている。保持構造の詳細を図６、図７に示す。カムドライバー７Ｂの内側面７１は、パッド３（図１）が設けられた側の内方から外方へ遠ざかるに従って下降する斜面に形成されており、曲げ刃５Ｂはその上面の内側半部５４が水平面になるとともに、外側半部５５がカムドライバー７Ｂの上記内側面７１に接するこれと同形の斜面になっている。カムドライバー７Ｂの両端部（図７に一方のみ示す）には内側面７１に沿って延びる矩形断面の凹所７２が形成され、これは下方から蓋材７３で閉鎖されてカムドライバー７Ｂの長手方向内方へ開くガイド溝となっている。そして、このガイド溝７２内に曲げ刃５Ｂのガイド突起５６が摺動可能に嵌装されており、このガイド突起５６は、曲げ刃５Ｂの上端外側半部５５からその長手方向外方へ水平に突出させられている。このような構造により、曲げ刃５Ｂはカムドライバー７Ｂに保持されるとともに、保持された状態でカムドライバー７Ｂの内側面７１に沿って一定以上の抵抗を有して移動可能である。なお、ガイド溝７２の両端はそれぞれストッパブロック７４，７５で閉鎖されている（図６）。なお、カムドライバー７Ａと曲げ刃５Ａの構造も上記と同様である。 The bending blades 5A and 5B are held by cam drivers 7A and 7B provided so as to protrude downward at the left and right positions of the mold surface of the upper mold 4. Details of the holding structure are shown in FIGS. The inner surface 71 of the cam driver 7B is formed on a slope that descends as it moves away from the inner side on the side where the pad 3 (FIG. 1) is provided, and the bending blade 5B has an inner half 54 on its upper surface. In addition to being a horizontal plane, the outer half 55 is an inclined surface having the same shape as that in contact with the inner surface 71 of the cam driver 7B. At both ends of the cam driver 7B (only one is shown in FIG. 7), a recess 72 having a rectangular cross section extending along the inner side surface 71 is formed, which is closed with a lid 73 from below, and the longitudinal direction of the cam driver 7B It is a guide groove that opens inward. A guide projection 56 of the bending blade 5B is slidably fitted in the guide groove 72, and the guide projection 56 is horizontally extended from the upper outer half 55 of the bending blade 5B outward in the longitudinal direction. It is made to protrude. With such a structure, the bending blade 5B is held by the cam driver 7B, and can move with a certain resistance or more along the inner surface 71 of the cam driver 7B while being held. Note that both ends of the guide groove 72 are closed by stopper blocks 74 and 75, respectively (FIG. 6). The structures of the cam driver 7A and the bending blade 5A are the same as described above.

図１において、曲げ刃５Ａ，５Ｂの下方の、下型１の型面上にはパンチ２を挟んで両側にカムドライバー６Ａ，６Ｂが設けられている。カムドライバー６Ａ，６Ｂは、パンチ２に向けて上り傾斜するように型面の一部に形成されたガイド面１１，１２上に摺動可能に載置されており、山形断面をなすその内側面６１は、上記曲げ刃５Ａ，５Ｂの外側面５３と平行な、外方からパンチ２が設けられた側の内方へ近づくに従って下降する斜面に形成されている。また、山形断面をなすカムドライバー６Ａ，６Ｂの外側面６２は上記カムドライバー７Ａ，７Ｂの内側面７１と同傾斜の斜面に形成されている。 In FIG. 1, cam drivers 6A and 6B are provided on both sides of the punch 2 on the mold surface of the lower mold 1 below the bending blades 5A and 5B. The cam drivers 6A and 6B are slidably mounted on guide surfaces 11 and 12 formed on a part of the mold surface so as to be inclined upward toward the punch 2, and the inner surface thereof forms a chevron cross section. 61 is formed in the slope parallel to the outer side surface 53 of the said bending blade 5A, 5B, and descend | falls as it approaches inward of the side in which the punch 2 was provided from the outside. Further, the outer side surfaces 62 of the cam drivers 6A and 6B having a mountain-shaped cross section are formed on a slope having the same inclination as the inner side surface 71 of the cam drivers 7A and 7B.

このような構造のプレス型において、図１の状態から上型４が下降すると、鋼板Ｐはその両端が図２に示すように曲げ刃５Ａ，５Ｂの突起５７により下方へ押圧されて変形し、鋼板Ｐ全体が上方へ凸状となるように湾曲する。さらに上型４が下降すると曲げ刃５Ａ，５Ｂはその外側面５３がカムドライバー６Ａ，６Ｂの内側面６１に当接して（図３）当該内側面６１の傾斜にしたがって下降しつつパンチ２の方向へ移動する。この移動は、曲げ刃５Ａ，５Ｂの内側面５２がパンチ本体部２２の側面２２１と常に平行を維持するように行われる。これによって、鋼板Ｐの両端はさらに下方へ変形させられて曲げ刃５Ａ，５Ｂの突起５７の上側へ移動させられ、ここに係止される。この過程で、曲げ刃５Ａ，５Ｂはカムドライバー７Ａ，７Ｂの内側面７１に沿って上方へ相対移動させられる。さらに上型４が下降すると、曲げ刃５Ａ，５Ｂはカムドライバー６Ａ，６Ｂの内側面６１に沿ってさらに下降しつつパンチ２に接近する方向へ移動し（図４）、これにより鋼板Ｐはパンチ２上に載置された中央部を除いた両端部がさらに深く下方へ変形させられる。この時、カムドライバー７Ａ，７Ｂの内側面７１がカムドライバー６Ａ，６Ｂの外側面６２に当接する。ここからさらに上型４が下降すると、カムドライバー６Ａ，６Ｂはその外側面６２がカムドライバー７Ａ，７Ｂの内側面７１に押圧されて、ガイド面１１，１２上をパンチ２に向けて斜め上方へ摺動させられる（図５）。 In the press die having such a structure, when the upper die 4 is lowered from the state of FIG. 1, the both ends of the steel plate P are pressed downward by the projections 57 of the bending blades 5A and 5B as shown in FIG. The entire steel plate P is curved so as to be convex upward. When the upper die 4 is further lowered, the outer surfaces 53 of the bending blades 5A and 5B come into contact with the inner side surfaces 61 of the cam drivers 6A and 6B (FIG. 3). Move to. This movement is performed so that the inner side surfaces 52 of the bending blades 5 A and 5 B are always kept parallel to the side surface 221 of the punch body 22. As a result, both ends of the steel plate P are further deformed downward, moved to the upper side of the projections 57 of the bending blades 5A and 5B, and locked there. In this process, the bending blades 5A and 5B are relatively moved upward along the inner surfaces 71 of the cam drivers 7A and 7B. When the upper die 4 is further lowered, the bending blades 5A and 5B are further lowered along the inner side surfaces 61 of the cam drivers 6A and 6B and move toward the punch 2 (FIG. 4). Both end portions excluding the central portion placed on 2 are further deformed downward. At this time, the inner side surfaces 71 of the cam drivers 7A and 7B abut against the outer side surfaces 62 of the cam drivers 6A and 6B. When the upper die 4 is further lowered from here, the outer surfaces 62 of the cam drivers 6A and 6B are pressed against the inner surfaces 71 of the cam drivers 7A and 7B, and the guide surfaces 11 and 12 are directed obliquely upward toward the punch 2. It is made to slide (FIG. 5).

これにより、曲げ刃５Ａ，５Ｂはその突起５７に鋼板Ｐの端縁を係止しつつ、内側面５２がパンチ本体部２２の側面２２１と平行を保った状態で斜め上方に移動させられて、パンチ本体部２２の側面２２１との間で鋼板Ｐの両端部を挟圧する。以上の過程において、曲げ刃５Ａ，５Ｂは図８から図９に示すようにカムドライバー７Ａ，７Ｂのガイド溝７２に案内されて内側面７１に沿って斜めに相対上昇させられる。鋼板Ｐはその端縁が突起５７に係止されているから伸長変形が規制されており、この状態でその両端部が曲げ刃５Ａ，５Ｂの内側面５２とパンチ本体部２２の側面２２１との間に挟圧される。これにより、上記両端部には圧縮力が付与されてその残留応力が除去され、この除去された状態で鋼板Ｐはパンチ本体２２の外周に沿った逆Ｕ字形に成形される。このようにして成形された鋼板Ｐには残留応力が残存していないから、スプリングバックにより形状が変化して成形不良を生じることはない。 Thereby, the bending blades 5A and 5B are moved obliquely upward in a state where the inner side surface 52 is kept parallel to the side surface 221 of the punch main body portion 22 while the edge of the steel plate P is locked to the protrusion 57. The both ends of the steel plate P are clamped between the side surfaces 221 of the punch body 22. In the above process, the bending blades 5A and 5B are guided by the guide grooves 72 of the cam drivers 7A and 7B and are relatively raised along the inner side surface 71 as shown in FIGS. Since the end edge of the steel plate P is locked to the protrusion 57, the extension deformation is restricted. In this state, both end portions of the inner surface 52 of the bending blades 5A and 5B and the side surface 221 of the punch main body portion 22 are restricted. It is pinched in between. As a result, a compressive force is applied to both end portions to remove the residual stress, and in this removed state, the steel sheet P is formed into an inverted U shape along the outer periphery of the punch body 22. Since no residual stress remains in the steel sheet P formed in this way, the shape does not change due to the spring back, and no defective molding occurs.

本発明の一実施形態を示す、プレス型の垂直断面図である。It is a vertical sectional view of a press die showing one embodiment of the present invention. プレス型の作動過程を示す垂直断面図である。It is a vertical sectional view showing the operation process of the press die. プレス型の作動過程を示す垂直断面図である。It is a vertical sectional view showing the operation process of the press die. プレス型の作動過程を示す垂直断面図である。It is a vertical sectional view showing the operation process of the press die. プレス型の作動過程を示す垂直断面図である。It is a vertical sectional view showing the operation process of the press die. カムドライバーと曲げ刃の正面図である。It is a front view of a cam driver and a bending blade. カムドライバーと曲げ刃の分解斜視図である。It is a disassembled perspective view of a cam driver and a bending blade. カムドライバーと曲げ刃の斜視図である。It is a perspective view of a cam driver and a bending blade. カムドライバーと曲げ刃の斜視図である。It is a perspective view of a cam driver and a bending blade. 従来のプレス型の要部垂直断面図である。It is a principal part vertical sectional view of the conventional press die. 従来のプレス型で成形された鋼板の断面図である。It is sectional drawing of the steel plate shape | molded with the conventional press die.

Explanation of symbols

１…下型、２…パンチ、３…パッド、４…上型、５Ａ，５Ｂ…曲げ刃、５２…内側面、５３…外側面、５７…突起、５５…外側半部、６Ａ，６Ｂ…カムドライバー、６２…外側面、７Ａ，７Ｂ…カムドライバー、７１…内側面、Ｐ…鋼板。 DESCRIPTION OF SYMBOLS 1 ... Lower type | mold, 2 ... Punch, 3 ... Pad, 4 ... Upper type | mold, 5A, 5B ... Bending blade, 52 ... Inner side surface, 53 ... Outer side surface, 57 ... Protrusion, 55 ... Outer half part, 6A, 6B ... Cam Driver, 62 ... outer side, 7A, 7B ... cam driver, 71 ... inner side, P ... steel plate.

Claims

A press die for bending a flat steel plate, provided in a lower die, a punch on which the steel plate is placed, a pad provided in an upper die, and sandwiching the steel plate by the punch, Provided in the upper die, lowered by lowering the upper die, bending by pushing down the end of the steel plate, and moving obliquely upward toward the punch immediately before the bending is completed And a bending blade for applying a compressive force in a direction to push up the end of the steel plate.

The press die according to claim 1, wherein the press die is provided in a lower die, and comes into contact with a slope opposite to a surface of the bending blade opposite to the punch by lowering of the bending blade due to lowering of the upper die, A first cam driver that presses the bending blade so as to move toward the punch as it lowers, and an upper die that is lowered by the lowering of the upper die, and the first cam driver moves toward the bending blade. A second cam driver whose lower slope presses the upper slope of the first cam driver so as to move, and the bending blade locks the end of the steel plate at the lower end of the surface facing the punch And the bending blade is moved obliquely upward in accordance with the movement of the first cam driver by the pressing of the second cam driver while the end of the steel plate is locked by the protrusion. Become Press type, characterized in that there.