JP6079854B2

JP6079854B2 - Bent member forming method and bent member manufacturing method

Info

Publication number: JP6079854B2
Application number: JP2015222670A
Authority: JP
Inventors: 貴之二塚; 山崎　雄司; 雄司山崎; 藤田　毅; 毅藤田
Original assignee: JFE Steel Corp
Current assignee: JFE Steel Corp
Priority date: 2015-11-13
Filing date: 2015-11-13
Publication date: 2017-02-15
Anticipated expiration: 2029-09-30
Also published as: JP2016040052A

Description

本発明は、平板を曲がり部材（詳しくは、曲がり形状を有するフレーム部材）に成形する方法に関し、特に、引張強さ（ＴＳ）が５９０ＭＰａ以上の高強度鋼板から曲がり部材への成形を可能とする成形方法および曲がり部材製造方法に関する。 The present invention relates to a method of forming a flat plate into a bent member (specifically, a frame member having a bent shape), and in particular, enables forming a bent member from a high strength steel plate having a tensile strength (TS) of 590 MPa or more. The present invention relates to a forming method and a bending member manufacturing method.

曲がり部材を得る手段として、従来では金属単板を絞り、張出し、伸びフランジおよび曲げの各種成形様式を複合したプレス成形（以後、従来プレス成形という）が行われている。さらには筒状部材を曲げ成形する方法（特許文献１）や、ロールフォーミング技術（特許文献２）や、中空部材を用いた曲げ成形（特許文献３，４）が提案されている。また曲り部材を補強する例として、発泡樹脂を充填する方法（特許文献５）が提案されている。 As a means for obtaining a bent member, conventionally, press molding (hereinafter, referred to as conventional press molding) in which various types of molding methods of drawing, stretching, stretching flange and bending are performed on a single metal plate is performed. Furthermore, a method of bending a cylindrical member (Patent Document 1), a roll forming technique (Patent Document 2), and a bending process using a hollow member (Patent Documents 3 and 4) have been proposed. As an example of reinforcing the bent member, a method of filling a foamed resin (Patent Document 5) has been proposed.

特開平９−３０３４５号公報Japanese Patent Laid-Open No. 9-30345 特開平１１−１２９０４５号公報Japanese Patent Application Laid-Open No. 11-129045 特開平８−１７４０４７号公報JP-A-8-174047 特開２００５−１４９０号公報JP 2005-1490 A 特開平１１−３４８８１３号公報Japanese Patent Laid-Open No. 11-348813

軽量化の要請に応じた鋼板の高強度化は、同時に鋼板の絞り・張出し・伸びフランジ成形性の低下を招くため、従来プレス成形では、割れやしわなどの不具合が発生し、特に形状が複雑になるにしたがい、曲がり部材が得られない場合が生じてきた。例えば、ＴＳで５９０ＭＰａ以上の高強度鋼板の単板を、従来プレス成形により図８に示すような曲がり部材５０を構成する部材５０Ａ、５０Ｂ（ＸＹ平面視の曲がりを有する）に成形すると、平面部にしわ（例えば図中の「シワ」部に発生）、側面縦壁部やフランジ部に割れ（例えば図中の「ワレ」部に発生）が発生してしまう。このとき、しわ押さえ等の成形条件の最適化あるいは部品形状変更により、ある程度まで割れ・しわの発生抑制を図ることが可能であるが、そのような方法では、軽量化ニーズに応えるための、ＴＳで９８０ＭＰａ以上の更なる高強度化に対応するには限界があると言える。 Increasing the strength of steel sheets in response to requests for weight reduction leads to a decrease in drawing, overhanging, and stretch flangeability of steel sheets. Accordingly, there has been a case where a bent member cannot be obtained. For example, when a single plate of a high strength steel plate having a TS of 590 MPa or more is formed into members 50A and 50B (having a curve in the XY plan view) constituting the bending member 50 as shown in FIG. Wrinkles (for example, occurring in “wrinkled” portions in the figure) and cracks in the side vertical wall portions and flange portions (for example, occurring in the “wrinkled” portions in the figure) will occur. At this time, it is possible to suppress the occurrence of cracks and wrinkles to some extent by optimizing the molding conditions such as wrinkle holding or changing the part shape. However, with such a method, TS to meet the need for weight reduction Therefore, it can be said that there is a limit to cope with further increase in strength of 980 MPa or more.

また、筒状の部材を曲げ成形する、あるいはロールフォーミングにより、高強度の曲がり部材を得る方法が開示されている（特許文献１〜４）が、工程上の制約や素材の成形性の観点から、複雑な曲がり形状を得ることが困難であり、かつ、工程数の増加など生産面で大きな課題がある。例えば、低強度の素材を用いる場合、複雑な形状が容易に得られる反面、部材強度が不足するため、発泡樹脂の充填により補強効果を得る技術等がある（特許文献５）が、コスト面、生産面、あるいはリサイクルの観点から必ずしも有用な技術とは言いがたいのが現状である。 In addition, a method for obtaining a high-strength bent member by bending a cylindrical member or roll forming is disclosed (Patent Documents 1 to 4), but from the viewpoint of process restrictions and material formability. In addition, it is difficult to obtain a complicated bent shape, and there are significant problems in production such as an increase in the number of processes. For example, when a low-strength material is used, a complicated shape can be easily obtained, but since the member strength is insufficient, there is a technique for obtaining a reinforcing effect by filling with a foamed resin (Patent Document 5). It is hard to say that the technology is always useful from the viewpoint of production or recycling.

すなわち、従来の成形方法では、高強度鋼板の単板を素材とする場合、一体プレス成形で所望の曲がり部材への成形が困難である、あるいは低強度鋼板の単板を素材とする場合、曲がり部材への成形は可能であるが、部材強度の不足を招くため、部品強度の増加など、生産面、コスト面で不利となるという課題があった。 That is, in the conventional forming method, when a single sheet of high-strength steel plate is used as a raw material, it is difficult to form a desired bent member by integral press forming, or when a single plate of low-strength steel plate is used as a raw material, Although molding to a member is possible, there is a problem in that it is disadvantageous in terms of production and cost, such as an increase in component strength, because the strength of the member is insufficient.

前記課題を解決するための本発明は、次のとおりである。
（１）引張強さが５９０ＭＰａ以上の高強度鋼板の単板からなるブランクを、プレス成形による曲げ加工で、長手方向曲がりの内周側をなす第一壁部の両側に第二壁部が連なる立体形状の曲がり部材に成形する曲がり部材成形方法であって、
前記曲がり部材のその長手方向曲がり部の箇所に、第一壁部の幅方向を山長手方向とする定幅の山形部と該定幅の山形部の両端に連なって第二壁部の幅方向を谷長手方向とする徐変幅の谷形部とを、
あるいは、
第一壁部の幅方向を谷長手方向とする定幅の谷形部と該定幅の谷形部の両端に連なって第二壁部の幅方向を山長手方向とする徐変幅の山形部とを、
折り曲げて形成するように、曲げ加工を行う曲げ工程を有し、
該曲げ工程の前に、
前記ブランクに対し、前記定幅もしくは徐変幅の山形部に対応させる部位および前記定幅もしくは徐変幅の谷形部に対応させる部位に、Ｖ字形又はＵ字形の溝の折り目をつける、
あるいは、
前記ブランクに対し、前記Ｖ字形又はＵ字形の溝の折り目をつける、とともに、切れ目を入れる、
予備工程を有し、
前記曲げ工程では前記Ｖ字形又はＵ字形の溝の折り目に沿って前記曲げ加工を行うことを特徴とする曲がり部材成形方法。
（２）上記（１）に記載された曲がり部材成形方法を用いて、曲がり部材を製造することを特徴とする曲がり部材製造方法。 The present invention for solving the above problems is as follows.
(1) A blank made of a single sheet of high-strength steel plate having a tensile strength of 590 MPa or more is bent by press forming, and the second wall portion is connected to both sides of the first wall portion forming the inner peripheral side of the longitudinal bending. A bending member forming method for forming a three-dimensional bent member,
A widthwise direction of the second wall connected to both ends of the constant-width chevron with the widthwise direction of the first wall being the longitudinal direction of the first wall at the location of the longitudinally curved part of the bending member A valley-shaped portion having a gradual change width with the valley longitudinal direction as
Or
A ridge having a constant width with the width direction of the first wall as the longitudinal direction of the valley, and a ridge with a gradually varying width with the width direction of the second wall connected to both ends of the valley as the longitudinal direction. Part
It has a bending process to bend so as to be bent,
Before the bending process,
For the blank, fold a V-shaped or U-shaped groove in a portion corresponding to the constant-width or gradually-variable width chevron and a portion corresponding to the constant-width or gradually-variable valley-shaped portion,
Or
Crease the V-shaped or U-shaped groove with respect to the blank, and make a cut;
Has a preliminary process,
In the bending step, the bending process is performed along the folds of the V-shaped or U-shaped grooves.
(2) A bending member manufacturing method, wherein a bending member is manufactured using the bending member forming method described in (1) above.

本発明によれば、材料は絞り・張出し・伸びフランジの各変形はほとんどせずに曲げ変形をするため、高強度鋼板の単板から曲がり部材を構成する部材への一体プレス成形が可能となる。さらに、成形目標とする曲がり部材の立体図形を平面展開した図形をブランクの輪郭形状に反映させることにより、従来では得られなかった部材強度の高いかつ複雑な曲がり形状を有する部材を容易に得ることができ、部品断面の縮小によるスペース拡大や、板厚の減少あるいは補強部材の廃止などによる高い軽量化効果が期待できる。 According to the present invention, since the material undergoes bending deformation with almost no deformation of the drawing, overhanging, and extension flange, it is possible to perform integral press molding from a single sheet of high-strength steel sheet to a member constituting the bending member. . Furthermore, by reflecting a figure obtained by planarly developing a three-dimensional figure of a bending member as a forming target in a blank outline shape, it is possible to easily obtain a member having a high member strength and a complicated bending shape that has not been obtained conventionally. It is possible to expect a large weight reduction effect by expanding the space by reducing the cross section of the component, reducing the plate thickness, or eliminating the reinforcing member.

本発明の実施形態の１例を示す概略図（(a)ブランクの平面図、(b)曲がり部材の立体図）Schematic showing an example of an embodiment of the present invention ((a) a plan view of a blank, (b) a three-dimensional view of a bending member) 本発明の実施形態の１例（既出例とは別の例）を示す概略図（(a)ブランクの平面図、(b)曲がり部材の立体図）Schematic showing one example of the embodiment of the present invention (an example different from the above-mentioned example) ((a) a plan view of a blank, (b) a three-dimensional view of a bent member) 本発明の実施形態の１例（既出例とは別の例）を示す概略図（(a)ブランクの平面図、(b)曲がり部材の立体図）Schematic showing one example of the embodiment of the present invention (an example different from the above-mentioned example) ((a) a plan view of a blank, (b) a three-dimensional view of a bent member) 本発明の実施形態の１例（既出例とは別の例）を示す概略図（(a)ブランクの平面図、(b)曲がり部材の立体図）Schematic showing one example of the embodiment of the present invention (an example different from the above-mentioned example) ((a) a plan view of a blank, (b) a three-dimensional view of a bent member) 本発明の実施形態の１例（既出例とは別の例）を示す概略図（(a)ブランクの平面図、(b)曲がり部材の立体図）Schematic showing one example of the embodiment of the present invention (an example different from the above-mentioned example) ((a) a plan view of a blank, (b) a three-dimensional view of a bent member) 本発明の実施形態の１例（既出例とは別の例）を示す概略図（(a)ブランクの平面図、(b)曲がり部材の立体図）Schematic showing one example of the embodiment of the present invention (an example different from the above-mentioned example) ((a) a plan view of a blank, (b) a three-dimensional view of a bent member) 折り目のつけ方の例を示す概略図Schematic showing an example of how to crease 従来プレス成形による曲がり部材の１例を示す概略図Schematic showing an example of a bending member by conventional press molding

図１〜図６は、それぞれ本発明の実施形態の相異なる例を示す概略図（(a)ブランクの平面図、(b)曲がり部材の立体図）である。なお、以下では、図２〜図６に関して「本発明」、「本発明例」とあるのはそれぞれ「参考発明」、「参考例」と読み替えるものとする。
図１の例では、成形目標である曲がり部材３０は、長手方向の１箇所で曲がっており、長手方向曲がりの内周側をなす第一壁部２の両側に第二壁部３が連なる立体形状を有する。 1 to 6 are schematic views ((a) a plan view of a blank and (b) a three-dimensional view of a bending member) showing different examples of embodiments of the present invention, respectively. In the following, “present invention” and “example of the present invention” with reference to FIGS. 2 to 6 shall be read as “reference invention” and “reference example”, respectively.
In the example of FIG. 1, the bending member 30 that is a forming target is bent at one location in the longitudinal direction, and the second wall portion 3 is connected to both sides of the first wall portion 2 that forms the inner peripheral side of the longitudinal bending. Has a shape.

曲がり部材３０の長手方向１箇所の曲がり部には、第一壁部２の幅方向を山長手方向とする定幅の山形部４と該定幅の山形部４の両端に連なって第二壁部３の幅方向を谷長手方向とする徐変幅の谷形部５とが存在する。ブランク１の平面図は、曲がり部材３０の平面展開図に相当し、同平面図中の、点線で示す山折りは曲がり部材３０の角稜線に対応し、破線で示す谷折りは曲がり部材３０の隅稜線に対応する。 A bent portion at one place in the longitudinal direction of the bending member 30 includes a constant-width chevron 4 with the width direction of the first wall 2 as the longitudinal direction of the first wall 2, and a second wall connected to both ends of the constant-width chevron 4. There is a valley-shaped portion 5 having a gradually changing width in which the width direction of the portion 3 is the longitudinal direction of the valley. The plan view of the blank 1 corresponds to a plan development view of the bending member 30, and a mountain fold indicated by a dotted line in the plan view corresponds to a corner ridge line of the bending member 30, and a valley fold indicated by a broken line is the bending member 30. Corresponds to the corner line.

ブランク１の平面図中の山折り、谷折りの部位がそれぞれ、成形後の曲がり部材３０における角稜線、隅稜線となるようにブランク１に曲げ加工を施すことにより、ブランク１の材料は絞り・張出し・伸びフランジの各変形はほとんどせずに曲げ変形し、成形目標である曲がり部材３０が得られる。このような曲げ加工は、例えば、予成形により山形部４を曲げ加工したのち、第二壁部３、谷形部５を曲げ加工することにより実現可能である。 By bending the blank 1 so that the portions of the mountain fold and valley fold in the plan view of the blank 1 become the corner ridge line and the corner ridge line in the bent member 30 after forming, the material of the blank 1 is drawn and drawn. The bending member 30 which is a forming target is obtained by bending and deforming the projecting and extending flanges with little deformation. Such a bending process is realizable by bending the 2nd wall part 3 and the valley-shaped part 5, for example after bending the mountain-shaped part 4 by preforming.

図２の例では、成形目標である曲がり部材３０は、長手方向の１箇所で曲がっており、長手方向曲がりの内周側をなす第一壁部２の両側に第二壁部３が連なり、さらに、第二壁部３の幅方向の反第一壁部２側の端にフランジ１０が連なる立体形状を有する。なお、フランジ１０の長手方向曲がり部には切れ目６が入っている。
曲がり部材３０の長手方向１箇所の曲がり部には、第一壁部２の幅方向を山長手方向とする定幅の山形部４と該定幅の山形部４の両端に連なって第二壁部３の幅方向を谷長手方向とする徐変幅の谷形部５とが存在する。ブランク１の平面図は、曲がり部材３０の平面展開図に相当し、同平面図中の、点線で示す山折りは曲がり部材３０の角稜線に対応し、破線で示す谷折りは曲がり部材３０の隅稜線に対応し、フランジ対応部１０Ａは曲がり部材３０のフランジ１０に対応し、切れ目６Ａは曲がり部材３０の切れ目６に対応する。 In the example of FIG. 2, the bending member 30 that is a forming target is bent at one location in the longitudinal direction, and the second wall portion 3 is connected to both sides of the first wall portion 2 that forms the inner peripheral side of the longitudinal bending, Furthermore, it has a solid shape in which the flange 10 is connected to the end of the second wall 3 on the side opposite to the first wall 2 in the width direction. In addition, the cut | interruption 6 has entered into the longitudinal direction bending part of the flange 10. As shown in FIG.
A bent portion at one place in the longitudinal direction of the bending member 30 includes a constant-width chevron 4 with the width direction of the first wall 2 as the longitudinal direction of the first wall 2, and a second wall connected to both ends of the constant-width chevron 4. There is a valley-shaped portion 5 having a gradually changing width in which the width direction of the portion 3 is the longitudinal direction of the valley. The plan view of the blank 1 corresponds to a plan development view of the bending member 30, and a mountain fold indicated by a dotted line in the plan view corresponds to a corner ridge line of the bending member 30, and a valley fold indicated by a broken line is the bending member 30. Corresponding to the corner ridge line, the flange corresponding portion 10 A corresponds to the flange 10 of the bent member 30, and the cut 6 A corresponds to the cut 6 of the bent member 30.

ブランク１に切れ目６Ａを入れた後、ブランク１の平面図中の山折り、谷折りの部位がそれぞれ、成形後の曲がり部材３０における角稜線、隅稜線となるようにブランク１に曲げ加工を施すことにより、ブランク１の材料は絞り・張出し・伸びフランジの各変形はほとんどせずに曲げ変形し、成形目標である曲がり部材３０が得られる。このような曲げ加工は、例えば、予成形により山形部４を曲げ加工したのち、第二壁部３、谷形部５を曲げ加工することにより実現可能である。 After the cut 6A is made in the blank 1, the blank 1 is bent so that the mountain fold and valley fold portions in the plan view of the blank 1 become the corner ridge line and the corner ridge line in the bent member 30 after forming, respectively. As a result, the material of the blank 1 is bent and deformed with little deformation of the squeezing, overhanging, and extension flange, and the bending member 30 that is a forming target is obtained. Such a bending process is realizable by bending the 2nd wall part 3 and the valley-shaped part 5, for example after bending the mountain-shaped part 4 by preforming.

図３の例では、成形目標である曲がり部材３０は、長手方向の１箇所で曲がっており、長手方向曲がりの内周側をなす第一壁部２の両側に第二壁部３が連なり、さらに、両側のうち一側の第二壁部３の幅方向の反第一壁部側の端と、他側の第二壁部３の幅方向の反第一壁部側の端部との双方に第三壁部１１が連なる立体形状を有する。
曲がり部材３０の長手方向１箇所の曲がり部には、第一壁部２の幅方向を山長手方向とする定幅の山形部４と該定幅の山形部４の両端に連なって第二壁部３の幅方向を谷長手方向とする徐変幅の谷形部５とが存在する。ブランク１の平面図は、曲がり部材３０の平面展開図に相当し、同平面図中の、点線で示す山折りは曲がり部材３０の角稜線に対応し、破線で示す谷折りは曲がり部材３０の隅稜線に対応し、ブランク１の幅方向両端部に位置する２つの第三壁部対応部１１Ａは曲がり部材３０の第三壁部１１に対応する。 In the example of FIG. 3, the bending member 30 that is a molding target is bent at one location in the longitudinal direction, and the second wall portion 3 is connected to both sides of the first wall portion 2 that forms the inner peripheral side of the longitudinal bending. Further, of the both sides, an end on the anti-first wall portion side in the width direction of the second wall portion 3 on one side and an end portion on the anti-first wall portion side in the width direction of the second wall portion 3 on the other side. It has a three-dimensional shape in which the third wall portion 11 is continuous on both sides.
A bent portion at one place in the longitudinal direction of the bending member 30 includes a constant-width chevron 4 with the width direction of the first wall 2 as the longitudinal direction of the first wall 2, and a second wall connected to both ends of the constant-width chevron 4. There is a valley-shaped portion 5 having a gradually changing width in which the width direction of the portion 3 is the longitudinal direction of the valley. The plan view of the blank 1 corresponds to a plan development view of the bending member 30, and a mountain fold indicated by a dotted line in the plan view corresponds to a corner ridge line of the bending member 30, and a valley fold indicated by a broken line is the bending member 30. The two third wall portion corresponding portions 11 A corresponding to the corner ridge lines and located at both ends in the width direction of the blank 1 correspond to the third wall portion 11 of the bending member 30.

なお、前記曲げ加工後、前記２つの第三壁部対応部１１Ａは分離した状態となっているが、必要に応じて、それらの幅方向自由端同士を接合して、閉断面化してもよい。接合方法としては、点溶接、連続溶接、リベット接合等々のいずれであってもよい。
図４の例では、成形目標である曲がり部材３０は、長手方向の１箇所で曲がっており、長手方向曲がりの内周側をなす第一壁部２の両側に第二壁部３が連なり、さらに、両側のうち一側の第二壁部３の幅方向の反第一壁部側の端と、他側の第二壁部３の幅方向の反第一壁部側の端部との双方に第三壁部１１が連なる立体形状を有する。 In addition, after the bending process, the two third wall corresponding portions 11A are in a separated state, but if necessary, their width direction free ends may be joined to form a closed cross section. . The joining method may be any of spot welding, continuous welding, rivet joining, and the like.
In the example of FIG. 4, the bending member 30 that is a molding target is bent at one location in the longitudinal direction, and the second wall portion 3 is connected to both sides of the first wall portion 2 that forms the inner peripheral side of the longitudinal bending, Further, of the both sides, an end on the anti-first wall portion side in the width direction of the second wall portion 3 on one side and an end portion on the anti-first wall portion side in the width direction of the second wall portion 3 on the other side. It has a three-dimensional shape in which the third wall portion 11 is continuous on both sides.

曲がり部材３０の長手方向１箇所の曲がり部には、第一壁部２の幅方向を谷長手方向とする定幅の谷形部７と該定幅の谷形部７の両端に連なって第二壁部３の幅方向を山長手方向とする徐変幅の山形部８とが存在する。ブランク１の平面図は、曲がり部材３０の平面展開図に相当し、同平面図中の、点線で示す山折りは曲がり部材３０の角稜線に対応し、破線で示す谷折りは曲がり部材３０の隅稜線に対応し、ブランク１の幅方向両端部に位置する２つの第三壁部対応部１１Ａは曲がり部材３０の第三壁部１１に対応する。 A bent portion at one place in the longitudinal direction of the bending member 30 is connected to both ends of the valley portion 7 having a constant width with the width direction of the first wall portion 2 being the longitudinal direction of the valley, and both ends of the valley portion 7 having the constant width. There is a mountain-shaped portion 8 having a gradually changing width in which the width direction of the two wall portions 3 is the mountain longitudinal direction. The plan view of the blank 1 corresponds to a plan development view of the bending member 30, and a mountain fold indicated by a dotted line in the plan view corresponds to a corner ridge line of the bending member 30, and a valley fold indicated by a broken line is the bending member 30. The two third wall portion corresponding portions 11 A corresponding to the corner ridge lines and located at both ends in the width direction of the blank 1 correspond to the third wall portion 11 of the bending member 30.

ブランク１の平面図中の山折り、谷折りの部位がそれぞれ、成形後の曲がり部材３０における角稜線、隅稜線となるようにブランク１に曲げ加工を施すことにより、ブランク１の材料は絞り・張出し・伸びフランジの各変形はほとんどせずに曲げ変形し、成形目標である曲がり部材３０が得られる。このような曲げ加工は、例えば、予成形により谷形部７を曲げ加工したのち、第二壁部３、山形部８を曲げ加工することにより実現可能である。 By bending the blank 1 so that the portions of the mountain fold and valley fold in the plan view of the blank 1 become the corner ridge line and the corner ridge line in the bent member 30 after forming, the material of the blank 1 is drawn and drawn. The bending member 30 which is a forming target is obtained by bending and deforming the projecting and extending flanges with little deformation. Such bending can be realized, for example, by bending the valley portion 7 by preforming and then bending the second wall portion 3 and the mountain portion 8.

なお、前記曲げ加工後、前記２つの第三壁部対応部１１Ａは分離した状態となっているが、必要に応じて、それらの幅方向自由端同士を接合して、閉断面化してもよい。接合方法としては、点溶接、連続溶接、リベット接合等々のいずれであってもよい。
図５の例では、成形目標である曲がり部材３０は、長手方向の２箇所で曲がっており、曲がりの方向は一方向であり、長手方向曲がりの内周側をなす第一壁部２の両側に第二壁部３が連なり、さらに、両側のうち一側の第二壁部３の幅方向の反第一壁部側の端と、他側の第二壁部３の幅方向の反第一壁部側の端部との双方に第三壁部１１が連なる立体形状を有する。 In addition, after the bending process, the two third wall corresponding portions 11A are in a separated state, but if necessary, their width direction free ends may be joined to form a closed cross section. . The joining method may be any of spot welding, continuous welding, rivet joining, and the like.
In the example of FIG. 5, the bending member 30 that is a forming target is bent at two places in the longitudinal direction, the bending direction is one direction, and both sides of the first wall portion 2 that forms the inner peripheral side of the bending in the longitudinal direction. The second wall portion 3 is connected to the second wall portion 3, and the end of the second wall portion 3 on the opposite side in the width direction of the second wall portion 3 on one side and the second width portion 3 on the opposite side of the second wall portion 3 on the other side. It has a three-dimensional shape in which the third wall portion 11 is continuous with both ends on the one wall portion side.

曲がり部材３０の長手方向２箇所の各曲がり部には、第一壁部２の幅方向を谷長手方向とする定幅の谷形部７と該定幅の谷形部７の両端に連なって第二壁部３の幅方向を山長手方向とする徐変幅の山形部８とが存在する。ブランク１の平面図は、曲がり部材３０の平面展開図に相当し、同平面図中の、点線で示す山折りは曲がり部材３０の角稜線に対応し、破線で示す谷折りは曲がり部材３０の隅稜線に対応し、ブランク１の幅方向両端部に位置する２つの第三壁部対応部１１Ａは曲がり部材３０の第三壁部１１に対応する。 In each bent portion at two places in the longitudinal direction of the bending member 30, it is connected to both ends of the valley portion 7 having a constant width with the width direction of the first wall portion 2 being the longitudinal direction of the valley, and both ends of the valley portion 7 having the constant width. There is a mountain-shaped portion 8 having a gradually changing width in which the width direction of the second wall portion 3 is the longitudinal direction of the mountain. The plan view of the blank 1 corresponds to a plan development view of the bending member 30, and a mountain fold indicated by a dotted line in the plan view corresponds to a corner ridge line of the bending member 30, and a valley fold indicated by a broken line is the bending member 30. The two third wall portion corresponding portions 11 A corresponding to the corner ridge lines and located at both ends in the width direction of the blank 1 correspond to the third wall portion 11 of the bending member 30.

なお、前記曲げ加工後、前記２つの第三壁部対応部１１Ａは分離した状態となっているが、必要に応じて、それらの幅方向自由端同士を接合して、閉断面化してもよい。接合方法としては、点溶接、連続溶接、リベット接合等々のいずれであってもよい。
図６の例では、成形目標である曲がり部材３０は、長手方向の２箇所で曲がっており、うち１箇所の曲がりＣ１ともう１箇所の曲がりＣ２とでは曲がりの方向が互いに直交している（Ｃ１が上下方向の曲がりであるとするとＣ２は左右方向の曲がりになる）。曲がりＣ１の曲がり部では、曲がりＣ１の内周側をなす第一壁部２_１の両側に第二壁部３_１が連なり、さらに、両側のうち一側の第二壁部３_１の幅方向の反第一壁部側の端と、他側の第二壁部３_１の幅方向の反第一壁部側の端部との双方に第三壁部１１_１が連なっている。また、曲がりＣ２の曲がり部では、曲がりＣ２の内周側をなす第一壁部２_２の両側に第二壁部３_２が連なり、さらに、両側のうち一側の第二壁部３_２の幅方向の反第一壁部側の端と、他側の第二壁部３_２の幅方向の反第一壁部側の端部との双方に第三壁部１１_２が連なっている。 In addition, after the bending process, the two third wall corresponding portions 11A are in a separated state, but if necessary, their width direction free ends may be joined to form a closed cross section. . The joining method may be any of spot welding, continuous welding, rivet joining, and the like.
In the example of FIG. 6, the bending member 30 that is a forming target is bent at two places in the longitudinal direction, and the bending directions of one bending C1 and the other bending C2 are orthogonal to each other ( If C1 is a vertical curve, C2 is a horizontal curve). The bend of the bend C1, the second wall portion 3 ₁ contiguous with both sides of the first wall portion 2 ₁ forming the inner peripheral side of the bending C1, furthermore, the second wall portion 3 ₁ of the width direction of the one side of both sides the end of the reaction the first wall portion, the third wall portion 11 ₁ on both the ends of the anti-first wall portion of the other side the second wall portion 3 ₁ of the width direction are continuous in. Further, the bent portion of the bend C2, the first wall portion 2 ₂ forming the inner peripheral side of the bending C2 second wall portion 3 ₂ is contiguous to both sides, further, one side of both sides of the second wall portion 3 ₂ the end of the reaction the first wall portion side in the width direction, and both the third wall portion 11 ₂ is continuous to the end portion of the anti-first wall portion of the other side the second wall portion 3 ₂ in the width direction.

そして、１箇所の曲がりＣ１ともう１箇所の曲がりＣ２とでは曲がりの方向が互いに直交しているから、曲がりＣ１の第一壁部２_１と曲がりＣ２の２つの第二壁部３_２のうちの１つとは同一であり、かつ、曲がりＣ１の２つの第二壁部３_１のうちの１つと曲がりＣ２の第一壁部２_２とは同一であり、かつ、曲がりＣ１の２つの第二壁部３_１のうちのもう１つと曲がりＣ２の第三壁部１１_２とは同一であり、かつ、曲がりＣ１の第三壁部１１_１と曲がりＣ２の２つの第二壁部３_２のうちのもう１つとは同一である。図６の例の曲がり部材３０はこのような立体形状を有する。 Then, since the direction of the bend at the bend C1 Tomo one point bending C2 of one point are orthogonal to each other, two of the second wall portion 3 ₂ of the first wall portion 2 ₁ a bending C2 of C1 bend one of the are the same and are identical to the first wall portion 2 ₂ bends C1 two second wall portion 3 one bend C2 of the _one and two second bend C1 the third wall portion 11 ₂ of the other one bend C2 of the walls 3 ₁ are the same and the third wall portion 11 of the bending C1 ₁ and bending two of the second wall portion 3 ₂ C2 Is the same as the other. The bending member 30 in the example of FIG. 6 has such a three-dimensional shape.

そして、曲がり部材３０の長手方向２箇所の各曲がり部には、第一壁部２（２_１，２_２）の幅方向を谷長手方向とする定幅の谷形部７と該定幅の谷形部７の両端に連なって第二壁部３（３_１，３_２）の幅方向を山長手方向とする徐変幅の山形部８とが存在する。ブランク１の平面図は、曲がり部材３０の平面展開図に相当し、同平面図中の、点線で示す山折りは曲がり部材３０の角稜線に対応し、破線で示す谷折りは曲がり部材３０の隅稜線に対応し、ブランク１の幅方向両端部に位置する２つの第三壁部対応部１１_１Ａは曲がり部材３０の曲がりＣ１の第三壁部１１_１に対応し、かつ、ブランク１の第三壁部対応部１１_１Ａに隣接する第三壁部対応部１１_２Ａは曲がり部材３０の曲がりＣ２の第三壁部１１_２に対応する。 And in each bending part of the longitudinal direction two places of the bending member 30, the constant width valley-shaped part 7 which makes the width direction of the 1st wall part 2 (2 ₁ , 2 ₂ ) the valley longitudinal direction, and this constant width A mountain-shaped portion 8 having a gradual change width, which is continuous with both ends of the valley-shaped portion 7 and has the width direction of the second wall portion 3 (3 ₁ , 3 ₂ ) as a mountain longitudinal direction, exists. The plan view of the blank 1 corresponds to a plan development view of the bending member 30, and a mountain fold indicated by a dotted line in the plan view corresponds to a corner ridge line of the bending member 30, and a valley fold indicated by a broken line is the bending member 30. corresponding to the corner ridge, two third wall portion corresponding portion 11 1 _a located on the both widthwise end portions of the blank 1 corresponds to the third wall portion 11 ₁ of the bending C1 bending member 30, and the blank 1 the third wall portion corresponding portion 11 ₂ a adjacent the third wall portion corresponding portion 11 ₁ a corresponding to the third wall portion 11 ₂ of the bend C2 bending member 30.

なお、前記曲げ加工後、前記２つの第三壁部対応部１１_１Ａ（２つの第二壁部３_２のうちの１つにも対応）は分離した状態となっているが、必要に応じて、それらの幅方向自由端同士を接合して、閉断面化してもよい。接合方法としては、点溶接、連続溶接、リベット接合等々のいずれであってもよい。
本発明における曲げ工程では、金型を用いてブランクの成形部位が目標部材の対応折り曲げ部となるように、プレス曲げ加工することで、被成形材は曲げ成形主体の変形をし、目標形状に成形される。 In addition, after the bending process, the two third wall portion corresponding portions 11 ₁ A (corresponding to one of the two second wall portions 3 ₂ ) are in a separated state. Then, these width direction free ends may be joined to form a closed cross section. The joining method may be any of spot welding, continuous welding, rivet joining, and the like.
In the bending process according to the present invention, the material to be molded is deformed by the bending process so that the blank forming part of the blank becomes the corresponding bent part of the target member by using a mold, and the target material is deformed. Molded.

さらに、本発明では、前記曲げ加工の際にこの曲げ加工部の位置精度を向上させるために、ブランクにおける前記山折り、谷折りの部位に、予め折り目をつけることが好ましい。折り目については、対象箇所全てにつけてもよいし、一部分につけて形状の精度を高めてもよい。この折り目をつける加工方法には、コイニング等が好ましく用いうる。また、ロール表面につけた凹凸形状を連続的に材料の表面に転写していく方法も挙げられる。かかる折り目の好適形態として、図７（ｄ）に示すようなＶ溝を、線状（ａ）、破線状（ｂ）または点線状（ｃ）、あるいはこれらを組み合わせた複合線状に設けた形態が挙げられる。ここで、Ｖ溝の深さは金属板厚み（略して板厚）の２０％以下が好ましい。Ｖ溝の深さが板厚の２０％を超える場合は、自動車骨格部材等で必要とされる部材強度の低下、あるいは折り曲げ部の割れを助長する可能性があり、さらに高強度の金属材料においては、溝を深くすること自体が容易ではなく、生産面やコスト面に大きな問題があるためである。 Furthermore, in the present invention, in order to improve the positional accuracy of the bent portion during the bending process, it is preferable to crease the mountain fold and valley fold portions of the blank in advance. About a crease | fold, you may attach to all the object locations, and you may attach to a part and may raise the precision of a shape. Coining or the like can be preferably used as the processing method for forming the crease. Moreover, the method of transferring the uneven | corrugated shape given to the roll surface to the surface of material continuously is also mentioned. As a preferable form of such a fold, a V-groove as shown in FIG. 7 (d) is provided in the form of a line (a), a broken line (b), a dotted line (c), or a combination of these. Is mentioned. Here, the depth of the V-groove is preferably 20% or less of the metal plate thickness (abbreviated plate thickness). When the depth of the V-groove exceeds 20% of the plate thickness, there is a possibility of promoting a reduction in member strength required for an automobile frame member or the like, or cracking of a bent portion. This is because it is not easy to deepen the groove itself, and there are serious problems in production and cost.

なお、溝の形態はＶ字形状に限らず（図７（ｄ）に例示したＶ溝に限らず）、Ｕ字など各種凹み形状でもよい。また、折り曲げ部の曲率半径を大きくとる場合は、溝を複数条平行に設けてもよい。
また、折り曲げの際に局部的に過大な伸びまたは縮み変形加工が加わって割れまたはしわが発生する危険性が高いと予想される局所（例えばブランクのフランジ対応箇所において過大な伸びまたは縮みフランジ加工を受けそうな複数の局所）が存在する場合、かかる局所に予め切れ目を入れておくと、割れまたはしわの発生をさらに確実に予防できて好ましい。 Note that the shape of the groove is not limited to the V shape (not limited to the V groove illustrated in FIG. 7D), and may be various concave shapes such as a U shape. Moreover, when taking the curvature radius of a bending part large, you may provide a several groove | channel in parallel.
In addition, it is expected that there is a high risk of cracking or wrinkling due to excessive elongation or shrinkage deformation processing locally when bending (for example, excessive elongation or shrinkage flange processing at a flange-corresponding portion of a blank). In the case where there are a plurality of local areas that are likely to be received, it is preferable to make a cut in such a local area in advance to prevent the occurrence of cracks or wrinkles more reliably.

表１に示す板厚および引張特性（降伏強さＹＳ、引張強さＴＳ、伸びＥｌ）を有する薄鋼板（材料記号Ａ，Ｂ，Ｃ）からなるブランクを、表２に示す成形方法で曲がり部材に成形し、得られた曲がり部材形状を目視観察して、成形方法を評価した。その結果、表２に示すとおり、従来プレス成形による比較例では、図８に示した「シワ」部にはしわが、「ワレ」部には割れが、それぞれ発生したのに対し、本発明例では、割れ、しわの発生はなく、ほぼ目標形状どおりの曲がり部材が得られた。 A blank made of a thin steel plate (material symbols A, B, C) having the thickness and tensile properties (yield strength YS, tensile strength TS, elongation El) shown in Table 1 is bent by the forming method shown in Table 2. The shape of the obtained bent member was visually observed to evaluate the forming method. As a result, as shown in Table 2, in the comparative example by the conventional press molding, wrinkles were generated in the “wrinkled” portion shown in FIG. Then, there was no generation of cracks and wrinkles, and a bent member almost according to the target shape was obtained.

表１に示す板厚および引張特性（降伏強さＹＳ、引張強さＴＳ、伸びＥｌ）を有する薄鋼板（材料記号Ａ，Ｂ，Ｃ）からなるブランクを、これに予め、図７に示すような線状、破線状あるいは点線状のＶ溝（Ｖ溝の深さを表３に示す）からなる折り目をつけた後、表３に示す成形方法で曲がり部材に成形し、得られた曲がり部材形状を目視観察して、成形方法を評価した。その結果、表３に示すとおり、本発明例では、割れ、しわの発生はなく、しかも、実施例１での本発明例と比べて目標形状との一致具合がさらに良好な（寸法精度が○である）、曲がり部材が得られた。 As shown in FIG. 7, a blank made of a thin steel plate (material symbols A, B, C) having the thickness and tensile properties (yield strength YS, tensile strength TS, elongation El) shown in Table 1 is preliminarily shown in FIG. After forming a crease composed of a straight, broken or dotted V-groove (the depth of the V-groove is shown in Table 3), it is formed into a bending member by the molding method shown in Table 3, and the obtained bending member The shape was visually observed to evaluate the molding method. As a result, as shown in Table 3, in the example of the present invention, cracks and wrinkles did not occur, and the degree of coincidence with the target shape was better than that of the example of the present invention in Example 1 (the dimensional accuracy was good). A bending member was obtained.

１ブランク
２，２_１，２_２第一壁部
３，３_１，３_２第二壁部
４定幅の山形部
５徐変幅の谷形部
６，６Ａ切れ目
７定幅の谷形部
８徐変幅の山形部
１０フランジ
１０Ａフランジ対応部
１１，１１_１，１１_２第三壁部
１１Ａ，１１_１Ａ，１１_２Ａ第三壁部対応部
３０本発明に係る曲がり部材（成形目標）
５０従来プレス成形による曲がり部材（添え符号Ａ，Ｂは曲がり部材５０を構成する部材） DESCRIPTION OF SYMBOLS 1 Blank 2, 2 ₁ , 2 ₂ 1st wall part 3, 3 ₁ , 3 ₂ 2nd wall part 4 Constant-width mountain-shaped part 5 Gradation-shaped valley-shaped part 6, 6A Break 7 Constant-width valley-shaped part 8 Slowly changing angle portion 10 Flange 10A Flange corresponding portion 11, 11 ₁ , 11 ₂ Third wall portion 11A, 11 ₁ A, 11 ₂ A Third wall corresponding portion 30 Bending member according to the present invention (molding target)
50 Bending member by conventional press molding (additional signs A and B are members constituting the bending member 50)

Claims

A blank made of a single sheet of high-strength steel plate with a tensile strength of 590 MPa or more is bent by press molding, and has a three-dimensional shape in which the second wall portion is connected to both sides of the first wall portion forming the inner peripheral side of the longitudinal bending. A bending member forming method for forming a bent member,
A widthwise direction of the second wall connected to both ends of the constant-width chevron with the widthwise direction of the first wall being the longitudinal direction of the first wall at the location of the longitudinally curved part of the bending member A valley-shaped portion having a gradual change width with the valley longitudinal direction as
Or
A ridge having a constant width with the width direction of the first wall as the longitudinal direction of the valley, and a ridge with a gradually varying width with the width direction of the second wall connected to both ends of the valley as the longitudinal direction. Part
It has a bending process to bend so as to be bent,
Before the bending process,
For the blank, fold a V-shaped or U-shaped groove in a portion corresponding to the constant-width or gradually-variable width chevron and a portion corresponding to the constant-width or gradually-variable valley-shaped portion,
Or
Crease the V-shaped or U-shaped groove with respect to the blank, and make a cut;
Has a preliminary process,
In the bending step, the bending process is performed along the folds of the V-shaped or U-shaped grooves.

The bending member manufacturing method characterized by manufacturing a bending member using the bending member shaping | molding method described in Claim 1.