JP5434107B2 - Repellent member molding method and repellent member - Google Patents

Description

  The present invention relates to a method for forming a repellent member, and in particular, in a method for forming a repellent member by press-molding a flat plate, particularly from a high-strength metal single plate having a tensile strength (TS) of 590 MPa or more. The present invention relates to a repellent member molding method and a repellent member that enable integral press molding to a member.

  As shown in Fig. 1, the repellent member used in automobile parts has a shape resembling a bee or a shamisen repellent, with a trapezoidal part 2 connected to a rectangular part 3 in a flared form. Have The cross-sectional shape (hereinafter also simply referred to as the cross-sectional shape) perpendicular to the member length direction (longitudinal direction of the rectangular portion) is a straight shape at the tip of the widening shape, and a U-shape at the other end (Fig. 1 (a)). Or it is a hat shape (FIG. 1 (b)) with flanges at both ends of the U-shape. The width and height when the U-shaped opening is the bottom, the trapezoidal part 2 has a lower height and a wider width toward the tip side, and the rectangular part 3 has a substantially constant height, and the width is It is almost constant or spreads slightly toward the tail end.

As a means for forming a metal single plate into a repellent member, conventionally, press forming in which deformations of drawing, overhanging, stretch flange and bending are combined is performed.
In addition, when a metal plate box (this is different from a repellent member in that it does not have a trapezoidal part) is manufactured by press molding, a plate generated at the corner of the box for the purpose of simplifying and automating the manufacturing process. A method of forming the remainder by folding is proposed (Patent Documents 1, 2, 3, and 4).

JP 54-1112775 A Japanese Patent Laid-Open No. 55-149736 Japanese Patent Laid-Open No. 56-11110 Japanese Patent Laid-Open No. 4-147729

  However, due to the increased strength of metal materials (abbreviated materials) in response to requests for weight reduction of the vehicle body, the drawability, overhang, stretch flange formability deteriorates, and the conventional deformation of draw, overhang, stretch flange, and bending has been reduced. By the combined press molding (this is referred to as “conventional press molding”), there has been a case where the target shape of the repellent member cannot be obtained due to molding defects such as cracks and wrinkles.

  For example, when a single plate made of a high-strength material (for example, a steel plate having a TS of more than 590 MPa) is formed into a repellent member by conventional press forming, as shown in FIG. 2 (a), a trapezoidal portion 2 and a rectangular portion 3 In the boundary portion, wrinkles on the upper surface portion and cracks at the side corners occur. At this time, when improving cracking and wrinkles by optimizing molding conditions such as wrinkle pressing or changing the part shape, there is a limit to responding to higher strength of 980 MPa or more to meet the need for weight reduction It can be said. For example, as shown in Fig. 2 (b) as an example of countermeasures, when the trapezoidal part 2 and rectangular part 3 are individually press-molded and joined by welding or the like to obtain a repellent member shape, the number of processes or parts are increased. There is a problem such as an increase in points.

In addition, when a steel plate having a TS of 590 MPa or less is applied, it is not preferable from the viewpoint of weight reduction because it causes an increase in weight such as increasing the plate thickness or adding a reinforcing member in order to satisfy the member strength.
That is, with a conventional forming method, a single sheet of high-strength steel sheet cannot be formed into a repellent member by integral press molding, and a single sheet of low-strength steel sheet can be formed into a repellent member. There is a problem in that the weight is increased due to insufficient member strength.

The present invention has been made to solve the above problems, and the gist of the present invention is as follows.
(Claim 1)
Using a metal flat plate as a starting material of the molded material, which, Ri Tsurana the trapezoidal portion is flared-shaped rectangular section, except the tip of the cross-sectional shape is flared shape perpendicular to the member are longitudinally U-shaped or It is a hat shape with flanges at both ends of the U-shape, and the width and height when the U-shaped opening is the bottom, the height is lower at the tip side in the trapezoidal portion, and the width increases. A repellent member forming method for forming a metal plate, comprising: a preliminary step of forming a plurality of folds on the metal flat plate; and a bending step of forming the plurality of folds on the metal plate to be bent portions of the repellent member. A method for forming a repellent member.
(Claim 2)
The repellent member molding method according to claim 1, wherein a cut is made in the molding material in the preliminary process.
(Claim 3)
The repellent member molding method according to claim 1 or 2, wherein a stopper is attached to at least a part of the molding material after the bending step.
(Claim 4)
The overlapping part is formed in at least a part of the molding material in the bending process or after the bending process, and the formed overlapping part is joined. A method for forming a repellent member.
(Claim 5)
5. The repellent member forming method according to claim 3, wherein a boundary portion between the trapezoidal portion and the rectangular portion is included in a portion where the stopper is attached or a portion where the overlapping portion is formed.
(Claim 6)
A repellent member produced by using the repellent member molding method according to any one of claims 1 to 5.

  According to the present invention, since the material to be molded starting from a metal flat plate undergoes bending deformation with almost no deformation of the drawing, overhanging, and extension flange, it is possible to change from a single sheet of high-strength steel sheet to a repellent member. Integrated press molding is possible. As a result, it is possible to manufacture a repellent member having a high member strength that could not be manufactured by conventional press molding, and a great lightening effect can be obtained by thinning the metal flat plate or eliminating the reinforcing member.

  In addition, since the shape of the boundary between the trapezoidal part and the rectangular part greatly affects the overall shape, the repellent member is excellent by attaching a stopper to this part or forming an overlapping part and joining it. It is possible to obtain a repellent member having dimensional accuracy. The boundary portion between the trapezoidal portion and the rectangular portion means a region including the boundary portion between the trapezoidal portion and the rectangular portion and the vicinity thereof.

Schematic diagram showing the shape of the repellent member ((a) U-shaped section, (b) Hat-shaped section) Explanatory drawing showing the problems of conventional press forming Explanatory drawing which shows one example (no cut, no flange) of the present invention Explanatory drawing which shows one example (with a notch, a flange, and no overlap part) of this invention Explanatory drawing which shows one example (with a notch, with a flange, with an overlap part) of this invention In the present invention, a form in which a stopper is attached to the repellent member in FIG. 3B ((a)), and a form in which an overlapping portion is formed and joined to the repellent member in FIG. 4B ((b), Explanatory drawing showing (c)) Explanatory drawing showing an example of the form of a fold ((a), (b), (c) is a plan view, (d) is a cross-sectional view)

  The repellent member according to the present invention has the member shape shown in FIG. 1 as a basic form, but is not limited thereto. In the member having the member shape shown in FIG. 1, (A) A flange is attached to the end of the member length direction (FIG. 4 (b)), (B) a U-shape and a hat shape are mixed in the member length direction, and (C) at least in the direction of the member length. Another part that closes the opening to the inner surface side of the cross-sectional shape is attached (FIG. 6), (D) In the hat-shaped cross-sectional shape, there is a portion where the flange portion and the flange portion partially overlap , (FIG. 5 (b)) including any one or two or more.

In the present invention, a flat metal plate (hereinafter referred to as a blank) having a predetermined shape is used as a starting material of the material to be molded, and this is formed into a repellent member in which a trapezoidal portion is formed in a rectangular shape and is continuously extended. The contour shape of the blank may be determined based on the contour shape of the plan development view of the shape of the repellent member to be formed.
First, a plurality of folds are made in the blank in the preliminary process. As a place to crease, a place corresponding to a bent portion of a three-dimensional figure before development in a plan development view of a shape of a repellent member to be formed is preferable. In addition, a crease is not limited only to attaching (continuously) over the whole part corresponding to the bending part of the three-dimensional figure before the said expansion | deployment, and depending on the case, it may apply only to a part of the said part. It may be attached (intermittently).

  For example, FIG. 7 shows a form in which a crease formed by the V-groove 9 is formed in a line shape, a broken line shape, or a dotted line shape so that a highly accurate bending position can be easily obtained on the plate portion corresponding to the bent portion. . Here, the depth of the V groove 9 is preferably 20% or less of the metal plate thickness. When the depth of the V-groove 9 exceeds 20% of the metal plate thickness, there is a possibility that the strength of the member required for an automobile frame member or the like may be reduced, or the bent portion may be cracked. In the material, it is not easy to deepen the groove itself, which may cause problems in production and equipment costs. The shape of the groove is not limited to the V shape illustrated in FIG. 7 and may be various concave shapes such as a U shape. Moreover, when making the curvature radius of a bending part large, you may provide a some groove | channel in parallel.

Coining or the like can be preferably used as a processing method for folding a blank.
Further, in the preliminary process, in addition to the fold, a cut may be made as necessary. As the part where the cut is made, cracks and wrinkles are generated due to a part where an overlapping portion is formed between the flanges, or a deformation other than a bending deformation (drawing, overhanging, extension flange deformation) in the bending process following the preliminary process. Expected locations are preferred.

Examples of the method of making a cut in the blank include a method of penetrating with a blade tool or a laser.
In the bending step subsequent to the preliminary step, the blank is bent so that the plurality of creases are formed into bent portions of the shaping target repellent member shape (abbreviated forming target shape). Such bending can be performed by press bending using a mold. By making a crease as described above, or by making further cuts, in the press bending process, almost only bending deformation can be caused to the material to be molded, and the material to be molded at the completion of the bending process is almost molded. It becomes a repellent member according to the target shape.

  Further, when the molding material after the bending process is completed is taken out from the mold, the dimensional accuracy of the molding material may be deteriorated due to the spring back or the like. In particular, in the case where deterioration of dimensional accuracy occurs in accordance with the increase in strength of a single metal plate, in order to prevent such deterioration of shape accuracy and hold the material to be molded after the bending process in the target shape, It is preferable to attach a stopper to at least a part of the material to be molded. Further, in order to hold the same as described above, it is also preferable to form an overlapping portion on at least a part of the material to be molded in the bending process or after the bending process, and to join the formed overlapping portion.

In that case, since the boundary part between the trapezoidal part and the rectangular part greatly affects the entire shape, the boundary between the trapezoidal part and the rectangular part is provided at the part where the stopper is attached or the part where the overlapping part is formed. Parts are preferably included.
Examples of the stopper include a plate-like stopper, a rod-like stopper, a gravel-like stopper, and a wire-like stopper. The material of the stopper is not particularly limited, and may be any metal, plastic, resin, or the like as long as it has sufficient strength to hold the target shape.

  As the formation target of the overlapping portion, a repellent member having a flange is preferable because it is easier to form the overlapping portion than a repellent member having no flange. In the case of a repellent member having a flange, an overlap portion can be easily formed by making the cut so that ends of adjacent flanges overlap each other during the bending process. Moreover, even when the overlapping portion is not formed between adjacent flange end portions, the overlapping portion can be easily formed by overlapping a separately prepared overlapping member such as a plate material with the flange.

As joining means for joining the overlapping portions, any of spot welding, caulking, rivet joining, adhesive application, etc. can be preferably used.
Hereinafter, a specific example will be described.
FIG. 3 shows an example in which a repellent member without a flange (FIG. 3B) is used as a molding target member. In a preliminary process, a blank 1 having a rectangular planar shape corresponding to a plan development view of the molding target member is shown. As the fold, mountain folds a1, a2, a3, a4, a5 and valley folds b1, b2 indicated by the same reference numerals as the corresponding bent portions of the forming target member are attached (FIG. 3 (a)).

In the bending process, the material to be molded is almost bent and deformed almost by the press molding process so that the fold of blank 1 becomes the corresponding bent part of the molding target member using a mold. Molded as usual.
After the bending process, for example, as shown in FIG. 6A, the dimensional accuracy can be maintained at a high level by attaching a stopper 10 to the boundary portion between the rectangular portion 3 and the trapezoidal portion 2.

  FIG. 4 shows an example in which a repellent member (FIG. 4 (b)) with flanges 20, 21, 22, 23, and 24 is used as a molding target member, and a substantially T-shaped planar shape corresponding to a plan development view of the molding target member. With respect to the blank 1, the folds in the preliminary process, the folds a1, a2, a3, a4, a5, the valley folds b1, b2, b3, b4, indicated by the same reference numerals as the corresponding bent portions of the forming target member B5, b6, and b7 are attached, and cuts c1 and c2 indicated by the same reference numerals as the corresponding cut portions of the forming target member are inserted (FIG. 4 (a)).

In the bending process, the material to be molded is almost bent and deformed almost by the press molding process so that the fold of blank 1 becomes the corresponding bent part of the molding target member using a mold. Molded as usual.
Further, after the bending process, for example, as shown in FIG. 6 (b), a plate material 15 is arranged at the boundary between the rectangular portion 3 and the trapezoidal portion 2 to form an overlapping portion 31 with the flanges 23, 24. By joining the portions 31, the dimensional accuracy can be kept high.

Further, after the bending process, for example, as shown in FIG. 6 (c), the plate material 16 is arranged so as to cover the opening portion of the U-shaped cross section in almost the entire length direction of the material to be molded, and the flanges 21, 22, By forming the overlapping part 31 with 23 and 24 and joining the overlapping part 31, the dimensional accuracy can be maintained at a high level and the member strength can be improved. However, the weight is increased as compared with FIG.
FIG. 5 shows an example in which a repellent member (FIG. 5 (b)) with flanges 20, 21, 22, 23, 24 and with an overlapping portion 30 is used as a forming target member, which corresponds to a plan development view of the forming target member. For the blank 1 having a substantially T-shaped planar shape, mountain folds a1, a2, a3, a4, a5, valley folds b1, b2 indicated by the same reference numerals as the corresponding bent portions of the forming target member as folds in the preliminary process , b3, b4, b5, b6, b7 and the cuts c1, c2, c3, c4 indicated by the same reference numerals as the corresponding cut portions of the forming target member are inserted (FIG. 5 (a)).

  In the bending process, the material to be molded is almost bent and deformed almost by the press molding process so that the fold of blank 1 becomes the corresponding bent part of the molding target member using a mold. Molded as usual. The overlapping portion 30 is formed at the boundary between the rectangular portion 3 and the trapezoidal portion 2 by the overlapping of the ends of the flanges 21 and 23 on the cut c3 side and the overlapping of the ends of the flanges 22 and 24 on the cut c4 side. It is formed.

  Furthermore, by joining the overlapping portion 30 after the bending process, the dimensional accuracy can be kept high.

  Thin steel plates (material symbols A, B, and C) having the thickness and tensile properties (yield strength YS, tensile strength TS, and elongation El) shown in Table 1 are formed into a repellent member by the forming method shown in Table 2. The molding method was evaluated by visually observing the obtained repellent member shape. As a result, as shown in Table 2, in the comparative example, wrinkles were generated at the site corresponding to the wrinkle generation site shown in FIG. 2 (a), and cracks were generated at the site corresponding to the crack generation site shown in FIG. Whereas each of them occurred, in the example of the present invention, such wrinkles and cracks did not occur. In addition, among the examples of the present invention, those in which stoppers were attached or overlapped portions were formed and joined (Nos. 6 to 9) were more excellent in dimensional accuracy.

  Thin steel plates (material symbols A, B, C) having the thickness and tensile properties (yield strength YS, tensile strength TS, elongation El) shown in Table 1 are formed into a repellent member by the forming method shown in Table 3. The molding method was evaluated by visually observing the obtained repellent member shape. The folds were formed in the V-groove shape shown in FIG. As a result, as shown in Table 3, in the example of the present invention, cracks and wrinkles did not occur at the sites corresponding to the cracks and wrinkle generation sites shown in FIG.

1 Blank (Metal flat plate with predetermined shape, material to be molded)
2 Trapezoid (or trapezoidal area)
3 Rectangular part (or rectangular part corresponding area)
9 V groove
10 Stopper
15,16 Plate (stacking material)
20,21,22,23,24 Flange (or flange compatible area)
30,31 Overlap
a1, a2, a3, a4, a5 Mountain fold (folded, folded part after forming)
b1, b2, b3, b4, b5, b6, b7 Valley fold (folded, folded after forming)
c1, c2, c3, c4 cut (cut part after molding)

Claims (6)

Using a metal flat plate as a starting material of the molded material, which, Ri Tsurana the trapezoidal portion is flared-shaped rectangular section, except the tip of the cross-sectional shape is flared shape perpendicular to the member are longitudinally U-shaped or It is a hat shape with flanges at both ends of the U-shape, and the width and height when the U-shaped opening is the bottom, the height is lower at the tip side in the trapezoidal portion, and the width increases. A repellent member forming method for forming a metal plate, comprising: a preliminary step of forming a plurality of folds on the metal flat plate; and a bending step of forming the plurality of folds on the metal plate to be bent portions of the repellent member. A method for forming a repellent member.   The repellent member molding method according to claim 1, wherein a cut is made in the molding material in the preliminary process.   The repellent member molding method according to claim 1 or 2, wherein a stopper is attached to at least a part of the molding material after the bending step.   The overlapping part is formed in at least a part of the molding material in the bending process or after the bending process, and the formed overlapping part is joined. A method for forming a repellent member.   5. The repellent member forming method according to claim 3, wherein a boundary portion between the trapezoidal portion and the rectangular portion is included in a portion where the stopper is attached or a portion where the overlapping portion is formed.   A repellent member produced by using the repellent member molding method according to any one of claims 1 to 5.

Images