JP2016203255A - Manufacturing method of press formed article and press device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a manufacturing method of a specific press formed article preventing occurrence of bending in a shorter side direction from a desired shape by a springback in which the specific press formed article is a press formed article comprising: a long top plate; ridge line parts at both end parts of the top plate in the shorter side direction; and a pair of vertical walls in which the end parts faces each other while each end part is connected with the ridge line part, and at least one of them is a curvature wall that is curved when viewed from an upper side of the top plate.SOLUTION: A manufacturing method of a press formed article including a pair of vertical walls in which a blank is pressed so that at least one of them is a curvature wall comprises: a first step for forming an intermediate molding in which a step part of the vertical walls protrudes into a side opposite to a side the vertical walls face each other and the step part is formed at the curvature wall along a longitudinal direction of the top plate; and a second step in which the intermediate molding is pressed and portions of the curvature wall which are closer to the other end side than the step part are moved to an opposite side of the facing side.SELECTED DRAWING: Figure 5

Description

  The present invention relates to a method for manufacturing a press-formed product and a press apparatus.

  The body of an automobile is assembled by superimposing edges of a large number of molded panels and joining them by spot welding to form a box, and joining structural members to the essential parts of the box by spot welding. For example, on the side part (body side) of an automobile body, as a structural member, a side sill joined to both side parts of a floor panel, an A pillar lower and an A pillar upper erected upward on the front part of the side sill, A roof rail joined to the upper end portion of the A pillar upper, and a B pillar that joins the side sill and the roof rail are used.

  Components of structural members such as an A pillar lower, an A pillar upper, and a roof rail (for example, each outer panel) generally have a top plate that extends in the longitudinal direction, and two components that are respectively connected to both sides of the top plate. Consists of a convex ridge line part, two vertical walls respectively connected to these two convex ridge line parts, two concave ridge line parts respectively connected to these two vertical wall parts, and two flanges respectively connected to these two concave ridge line parts Often has a substantially hat-shaped cross-sectional shape.

  The aforementioned components have a relatively complex cross-sectional shape and are long. Therefore, in order to suppress an increase in manufacturing cost, the above-described components are generally manufactured by cold press molding. Further, in order to achieve both weight reduction and strength improvement of the vehicle body for improving fuel efficiency, thinning using, for example, a high-tensile steel plate having a tensile strength of 440 MPa or more is promoted as the above-described structural member.

  However, a high-tensile steel plate is bent in the longitudinal direction by cold press forming, for example, a roof rail outer panel (hereinafter referred to as a roof member. The roof member is a structural member of an automobile). When it is going to manufacture a component, a springback may generate | occur | produce at the time of mold release from a press type | mold, and there exists a possibility that a top plate may twist. As a result, there arises a problem of shape freezing property that the roof member cannot be formed into a desired shape.

  For example, Patent Document 1 discloses an invention in which, when a press-formed product having a hat-shaped cross section that is uniform in the longitudinal direction is manufactured, the generation of a mouth opening is suppressed by imparting a step to increase the shape freezing property. It is disclosed.

  Further, in Patent Document 2, when manufacturing a press-formed product having a top plate, a vertical wall, and a flange and curved in the longitudinal direction, the flange formed in the first step is bent back in the second step to An invention is disclosed in which the shape freezing property is improved by reducing the residual stress.

JP 2004-31423 A Japanese Patent No. 5382281

  According to the invention disclosed in Patent Document 1, for example, when a press-molded product having a shape curved in the longitudinal direction, such as a component of a component of an A pillar lower, an A pillar upper, and a roof rail, is manufactured, a spring after release The curved wall is bent by the back and cannot be formed into a desired shape.

  According to the invention disclosed in Patent Document 2, when a press-formed product that is curved in the longitudinal direction and the height direction is manufactured, the residual stress of the flange, the residual stress in the surface of the vertical wall and the top plate, and the surface of the vertical wall and the top plate Deviation residual stress is generated. As a result, the press-molded product is bent from the top plate side by the spring back after mold release (bending in the short direction of the top plate) and cannot be molded into a desired shape.

  An object of this invention is to provide the manufacturing method of the specific press molded product by which generation | occurrence | production of the bending seen from the top plate side was suppressed. Here, the specific press-formed product is a long top plate, a ridge line portion at both ends in the short direction of the top plate, and each end facing each other in a state where the one end is connected to the ridge line portion, at least one of the above This refers to a press-molded product that includes a pair of vertical walls that are curved as viewed from above the top plate (hereinafter the same applies in this specification).

  The method for producing a press-formed product according to the present invention includes a long top plate, ridge line portions at both ends in the short direction of the top plate, and each end facing each other with at least one connected to the ridge line portion. Is a method of manufacturing a press-molded product that includes a pair of vertical walls that are curved as viewed from above the top plate, pressing a blank, and the top plate, Including a pair of vertical walls that are opposite to each other in a state in which each end is connected to the ridge line portion, and at least one of which is a curved wall that is curved when viewed from above the top plate. A first step of forming an intermediate molded product having a stepped portion formed on the curved wall in a longitudinal direction of the top plate, the stepped portion projecting to the opposite side and the opposite side of the vertical wall, A part on the other end side than the step portion in the curved wall by pressing the intermediate molded product And a second step of moving to the opposite side and the opposite side.

  The press device according to the present invention presses a blank to face each other in a state where the top plate, the ridge line portions at both ends, and each one end are connected to the ridge line portion, and at least one of the top plate is from above the top plate. A first press device for forming an intermediate molded product formed on a pair of vertical walls, which are curved walls as viewed, and presses the intermediate molded product to provide other than the stepped portion on the curved wall. And a second press device that moves the end portion to the opposite side to the opposite side.

  Moreover, the press apparatus which concerns on this invention presses a blank with a 1st die and a 1st punch, the 1st press apparatus which shape | molds an intermediate molded product, and the said intermediate molded product with a 2nd die and a 2nd punch. A pressing device comprising a second pressing device for pressing, wherein the first die has a long first bottom surface, and each end is connected to an end portion of the first bottom surface in the short direction and faces each other. A long first groove configured to include the first side surface is formed, and at least one of the first side surfaces is curved when viewed from the mold closing direction, and a first width of the first side surface is increased. The first step portion is a first curved surface formed over the longitudinal direction of the first side surface, and the shape of the first punch is a shape that fits with the shape of the first groove when the mold is closed. 1 press device, the second die has a long second bottom surface, and each end is short of the second bottom surface. A long second groove is formed that includes second side surfaces that are connected to end portions in the direction and are opposed to each other, and at least one of the second side surfaces is curved when viewed from the mold closing direction, The second curved surface has a second stepped portion formed at a position corresponding to the one stepped portion, and a portion of the second curved surface on the other end side than the second stepped portion is inclined with respect to the mold closing direction. The angle of the second punch is larger than the angle at which the portion on the other end side of the first step surface of the first curved surface is inclined with respect to the mold closing direction. A second press device having a shape that fits with the shape of the second groove.

  By using the method for manufacturing a press-formed product according to the present invention, it is possible to manufacture a specific press-formed product in which the occurrence of bending in the short direction due to springback from the desired shape of the specific press-formed product is suppressed.

  If the press apparatus which concerns on this invention is used, the specific press molded product by which generation | occurrence | production of the bending to the transversal direction by the springback from the desired shape of a specific press molded product could be manufactured.

It is the figure of the roof member of 1st Embodiment, Comprising: It is the perspective view shown including the cross-sectional view in a longitudinal direction. It is a figure which shows sectional drawing of the roof member of 1st Embodiment, Comprising: It is the 2-2 sectional view taken on the line in FIG. It is a figure of the intermediate molded product of 1st Embodiment, Comprising: It is the perspective view shown including the cross-sectional view in a longitudinal direction. It is a figure which shows the cross-sectional view of the intermediate molded product of 1st Embodiment, Comprising: It is the 4-4 sectional view taken on the line in FIG. FIG. 5 is a schematic diagram in which a part of the cross-sectional view of FIG. 2 (two-dot chain line) is superimposed on a part of the cross-sectional view of FIG. 4 (solid line). It is a perspective view of the metal mold | die of the 1st press apparatus used at the 1st process in the manufacturing method of the roof member of a 1st embodiment. It is a transverse cross section of the 1st press device used at the 1st process in the manufacturing method of the roof member of a 1st embodiment, and a blank. It is a perspective view of the metal mold | die of the 2nd press apparatus used at the 2nd process in the manufacturing method of the roof member of 1st Embodiment. It is a cross-sectional view of the second press device used in the second step in the method for manufacturing the roof member of the first embodiment and the intermediate molded product. It is a figure for demonstrating the evaluation method of bending. It is the figure of the roof member of 2nd Embodiment, Comprising: It is the perspective view shown including the cross-sectional view in a longitudinal direction. It is a figure which shows sectional drawing of the roof member of 2nd Embodiment, Comprising: It is the 12-12 sectional view taken on the line in FIG. It is a figure for demonstrating the outer side vertical wall change start point and the inner side vertical wall change start point in an Example and a comparative example. It is a table | surface which shows the evaluation result by the simulation about the bending of the roof member of the Example (Examples 1-19) of 1st Embodiment, and the bending of the roof member of a comparative example (comparative examples 1-6). It is a table | surface which shows the evaluation result by the simulation about the bending of the roof member of the Example (Examples 20-37) of 2nd Embodiment, and the bending of the roof member of a comparative example (comparative examples 7-12).

≪Overview≫
Hereinafter, modes (embodiments) for carrying out the present invention will be described by exemplifying two embodiments (first and second embodiments). Next, examples will be described.

<< First Embodiment >>
The first embodiment will be described below. First, the structure of the roof member 1 (refer FIG.1 and FIG.2) of this embodiment is demonstrated. Next, the configuration of the press device 17 (see FIGS. 6, 7, 8, and 9) of the present embodiment will be described. Next, a method for manufacturing the roof member 1 of the present embodiment will be described. Next, the operation of this embodiment will be described. Note that the roof member of the present embodiment corresponds to Example 9 in an example described later (see FIG. 14).

<Configuration of roof member>
First, the structure of the roof member 1 of this embodiment is demonstrated, referring drawings. Here, the roof member 1 is an example of a press-formed product and a specific press-formed product.

  As shown in FIGS. 1 and 2, the roof member 1 includes a top plate 2, two convex ridge line portions 3a and 3b, two vertical walls 4a and 4b, and two concave ridge line portions 5a and 5b. The cross-sectional shape which is comprised including the two flanges 6a and 6b integrally is a substantially hat-shaped long member. Here, the convex ridge line portions 3a and 3b are examples of the ridge line portion. As an example, the roof member 1 is a cold press-formed product made of a high-tensile steel plate having a tensile strength of 1470 MPa.

  The top plate 2 is long as shown in FIG. Further, the top plate 2 is along the longitudinal direction (the direction of the arrow L1 in the figure) when viewed from the upper side (of the top plate 2). The two convex ridge line portions 3 a and 3 b are formed at both ends of the top plate 2 in the short direction. The two vertical walls 4a and 4b are opposed to each other with one end connected to the convex ridge portions 3a and 3b. That is, the roof member 1 of the present embodiment is a state in which the long top plate 2, the convex ridge line portions 3a and 3b at both ends in the short direction of the top plate 2, and one end connected to the convex ridge line portions 3a and 3b. It is comprised including the vertical walls 4a and 4b which mutually oppose. Further, as shown in FIG. 1, the two vertical walls 4 a and 4 b are curved along the longitudinal direction of the top plate 2 when viewed from above the top plate 2. That is, the two vertical walls 4a and 4b of the present embodiment are curved walls in which at least one (both in the case of the present embodiment) is curved as viewed from above the top plate 2. Here, the vertical wall 4a is an example of a curved wall. In the present embodiment, as an example, the vertical wall 4a is curved in a convex shape toward the opposite side to the vertical wall 4b side (the side facing the vertical wall 4b side), and the vertical wall 4b is the vertical wall 4a side (vertical side). It is curved in a concave shape toward the side opposite to the side facing the wall 4a.

  In addition, each vertical section (transverse section) in the longitudinal direction of the top plate 2 of the present embodiment extends linearly in the lateral direction at each position in the longitudinal direction as an example (see FIG. 1). That is, the top plate 2 of the present embodiment is flat at each position in the longitudinal direction when viewed in vertical sections in the longitudinal direction (see FIG. 2). Here, as shown in FIG. 2, the convex ridge line portion 3 a is a portion that connects the top plate 2 and the vertical wall 4 a, and is curved when the vertical cross sections of the top plate 2 in the longitudinal direction are viewed. It is supposed to be a part. Two alternate long and short dash lines in the figure indicate both ends of the convex ridge line portion 3a connected to the top plate 2 and the vertical wall 4a, respectively. The convex ridge line portion 3b is not shown at both ends by the alternate long and short dash line, but is a portion connecting the top plate 2 and the vertical wall 4b. It is supposed to be a part.

  In addition, as shown in FIG. 2, the two concave ridge line portions 5 a and 5 b are formed at the ends of the two vertical walls 4 a and 4 b opposite to the side connected to the top plate 2. The two flanges 6a and 6b are connected to the two concave ridge lines 5a and 5b, respectively. The concave ridge line portion 5a is not shown at both ends by the alternate long and short dash line, but is a portion that connects the vertical wall 4a and the flange 6a, and is curved when viewed in each cross section perpendicular to the longitudinal direction of the top plate 2. It is supposed to be a part. In addition, the concave ridge line portion 5b is not shown at both ends by the alternate long and short dash line, but is a portion that connects the vertical wall 4b and the flange 6b, and is curved when viewed in a cross section perpendicular to the longitudinal direction of the top plate 2. It is said that it is a part.

  As shown in FIG. 1, the roof member 1 is curved from one end 1 a in the longitudinal direction to the other end 1 b when viewed from the top plate 2 side. Further, the roof member 1 includes a first portion 8 including one end 1a, a third portion 10 including the other end 1b, and a second portion 9 connecting the first portion 8 and the third portion 10. It can be said that it is comprised integrally.

  Here, in this embodiment, when viewed from the top plate 2 side, the curvature radius of the first portion 8 is, for example, 2000 (mm) or more and 9000 (mm) or less, and the curvature radius of the second portion 9 is an example. As an example, the radius of curvature of the third portion 10 is 2500 (mm) or more and 9000 (mm) or less.

  As shown in FIG. 2, the plate thickness center of the R starting point (R stop) on the top plate 2 side of the convex ridge line portion 3 a, that is, from the plate thickness center of the top plate 2 to the concave ridge line portion 5 a side in the vertical wall 4 a The height to the end (the lower end of the vertical wall 4a) is defined as a height h. Then, on the vertical wall 4a, a step portion 11a having a step amount a2 (mm) is formed in the longitudinal direction at a portion separated from the thickness center of the top plate 2 by 40% or more of the height h. Moreover, the height h from the plate thickness center of the R start point (R stop) on the top plate 2 side of the convex ridge line portion 3b, that is, the plate thickness center of the top plate 2 to the lower end of the vertical wall 4b is defined as a height h ′. . Then, on the vertical wall 4b, a step portion 11a ′ having a step amount a2 ′ (mm) is formed in the longitudinal direction at a portion separated by 40% or more of the height h ′ from the thickness center of the top plate 2. ing. In this specification, the thickness center of the top plate 2 is defined as a position in the height direction of the top plate 2. The protruding widths a2 and a2 ′ of the step portions 11a and 11a ′ are 20% or less of the width W in the short direction of the top plate 2 at each position at each position in the longitudinal direction of the top plate 2. .

  Of the two ends of the stepped portion 11a, a portion closer to the top plate 2 (upper side) is a recess 11a1, and a portion farther from the top plate 2 (lower side) is a projection 11a2. Further, of the both ends of the stepped portion 11b, a portion closer to the top plate 2 (upper side) is a recess 11a'1, and a portion farther from the top plate 2 (lower side) is a projection 11a'2. Then, when generalizing both ends of the stepped portions 11a and 11a ', it can be paraphrased as follows. The concave portion 11a1 that is the end (upper side) near the top plate 2 of both ends of the stepped portion 11a is a portion that forms a radius of curvature that is the largest convex on the inner surface side on the inner surface of the vertical wall 4a. The convex portion 11a2 that is the end on the far side (lower side) from the plate 2 is a portion that forms a radius of curvature that is most convex on the outer surface side on the inner surface of the vertical wall 4a. Further, the concave portion 11a′1 which is the end (upper side) closer to the top plate 2 among both ends of the stepped portion 11a ′ forms a radius of curvature that is most convex on the inner surface side of the inner surface of the vertical wall 4b. The convex portion 11a′2 that is the end of the part, the far side (lower side) from the top plate 2 is a part that forms a radius of curvature that is the largest convex on the outer surface side on the inner surface of the vertical wall 4b. As shown in FIG. 2, the protrusion width a2 of the stepped portion 11a is such that when viewed in a cross section perpendicular to the longitudinal direction of the roof member 1, the protrusion 11a2 and the recess 11a1 in the short direction of the top plate 2 This is the separation width. Further, the protrusion width a2 ′ of the stepped portion 11a ′ is the separation width between the convex portion 11a2 ′ and the concave portion 11a1 ′ in the short direction of the top plate 2 when the cross section perpendicular to the longitudinal direction of the roof member 1 is viewed. That means.

  In the roof member 1, the cross-sectional shapes of the flanges 6a and 6b are different at one end 1a and the other end 1b in the longitudinal direction (not shown). The angle of the flange 6b with respect to the vertical wall 4b is 30 ° at the one end 1a and 40 ° at the other end 1b. And the angle of the flanges 6a and 6b with respect to the vertical wall 4a is changing continuously over the longitudinal direction, respectively. Further, the width in the short direction of the top plate 2 changes so as to continuously widen from one end 1a to the other end 1b in the longitudinal direction.

  The above is description about the structure of the roof member 1 of this embodiment.

<Configuration of press machine>
Next, the press apparatus 17 of this embodiment is demonstrated, referring drawings. The press apparatus 17 of this embodiment is for manufacturing the roof member 1 of this embodiment. As shown in FIGS. 6, 7, 8, and 9, the press device 17 includes a first press device 18 and a second press device 19. In the press device 17 of the present embodiment, the blank 25 (see FIG. 7) is press-formed by drawing using the first press device 18 to form an intermediate molded product 30 (see FIGS. 3 and 4), and then The intermediate molded product 30 is press-molded by the second press device 19 to manufacture the product, that is, the roof member 1. The blank 25 is a long high-tensile steel plate that is a base material for manufacturing the roof member 1.

  Here, as shown in FIGS. 3 and 4, the intermediate molded product 30 includes the top plate 2, the two convex ridge lines 3 a and 3 b, the two vertical walls 33 a and 33 b, and the two concave ridge lines 34 a. , 34b and the two flanges 35a, 35b are substantially hat-shaped members. Further, step portions 11a and 11a 'extending from one end to the other end in the longitudinal direction of the vertical walls 33a and 33b are formed on the two vertical walls 33a and 33b, respectively. In the present specification, “press molding” refers to a molding target product (for example, blank 25 and intermediate molded product 30) as a mold (for example, first mold 20 and second mold described later). It refers to the action from setting to mold 40) to closing the mold and opening the mold. Note that “press forming” means pressing (pressurizing) a product to be formed and forming.

[First press machine]
The first press device 18 has a function of pressing the blank 25 which is a molding target product and molding the intermediate molded product 30.

  The 1st press apparatus 18 is comprised including the 1st metal mold | die 20 and the 1st moving apparatus 25 as FIG. 7 shows. As shown in FIGS. 6 and 7, the first mold 20 has an upper die (die) 21, a lower die (punch) 22, a first holder 23, and a second holder 24. ing. The upper mold 21 is disposed on the upper side, and the lower mold 22 is disposed on the lower side.

  The upper mold 21 and the lower mold 22 are each long as shown in FIG. When the upper mold 21 and the lower mold 22 are viewed from the facing direction of the upper mold 21 and the lower mold 22, the lower mold 22 is curved and protrudes along the longitudinal direction. A groove that is curved is formed. Further, when viewed from the short side of the upper mold 21, the upper mold 21 has a groove width that is continuously increased from the bottom of the groove toward the opening side of the groove (from the upper side to the lower side). . When viewed from the short direction of the lower mold 22, the width of the protruding portion of the lower mold 22 is continuously narrowed from the lower side to the upper side. And the shape of the lower mold | type 22 is made into the shape fitted according to the shape of the groove | channel of the upper mold | type 21 at the time of mold closing.

  Further, as shown in FIG. 7, when the lower mold 22 is viewed from the longitudinal direction, stepped portions 22 a are formed on both side surfaces of the lower mold 22. Further, on both side surfaces of the groove of the upper mold 21, step portions 21a and 21a 'are formed along the step portion 22a. In addition, the inclination angle of the portion below the stepped portion 21a on the side surface where the stepped portion 21a is formed with respect to the vertical direction (the opposing direction of the upper mold 21 and the lower mold 22) is θ1.

  The first holder 23 and the second holder 24 are elongated along the upper mold 21 and the lower mold 22. As shown in FIGS. 6 and 7, the first holder 23 and the second holder 24 are respectively disposed on both sides of the lower mold 22 in the short direction. Further, the first holder 23 and the second holder 24 are urged upward by springs 26 and 27 as shown in FIG.

  The first moving device 25 is configured to move the upper mold 21 toward the lower mold 22. That is, the first moving device moves the upper mold 21 relative to the lower mold 22.

  When the first moving device moves the upper mold 21 toward the lower mold 22 in a state where the blank 25 is arranged at a position where the gap between the upper mold 21 and the lower mold 22 is defined, as shown in FIG. In addition, the blank 25 is pressed so that the intermediate molded product 30 is formed in a state where both ends in the short direction of the blank 25 are sandwiched between the first holder 23 and the second holder 24 and the upper die 21, respectively. It has become. And with shaping | molding of the intermediate molded product 30, the blank 25 is pressed by level | step-difference part 22a (22a ') and level | step-difference part 21a (21a'), and it is vertical from the position of the top plate 2 in the vertical walls 33a and 33b. Step portions 11a and 11a ′ having a protruding width a1 (mm) are formed at portions separated by 40% or more of the height of the walls 33a and 33b (see FIG. 4). Since the shape of the groove of the upper die 21 and the shape of the protruding portion of the lower die 22 are as described above, the stepped portions 21a and 21a 'are on the top plate 2 side when viewed from the longitudinal direction of the top plate 2. Further, they are inclined so that the facing distance between them becomes larger (the facing width is widened) on the opening side. From another viewpoint, the stepped portions 21a and 21a 'are inclined so that the facing distance between them is larger on the opening side than on the top plate 2 side.

  Although the 1st press apparatus 18 was demonstrated as mentioned above, it will become as follows if another viewpoint is seen about the 1st press apparatus 18. FIG. That is, the upper die 21 (an example of the first die) includes a long bottom surface (first bottom surface) and side surfaces (first side surfaces) that face each other with each end connected to both ends of the bottom surface in the short direction. A long groove (an example of a first groove) is formed. The side surface (first side surface) is curved when viewed from the mold closing direction (opposite direction between the upper mold 21 and the lower mold 22), and the depth of the groove (first groove) is 40 from the bottom surface (first bottom surface). The stepped portions 11a and 11a ′ (first stepped portions) having a width of 20% or less of the width of the bottom surface (an example of the first bottom surface) in the longitudinal direction of the side surface (first side surface) A curved surface (an example of a first curved surface) formed over the entire surface. Further, the lower mold 22 (an example of the first punch) is adapted to fit in the groove (first groove) when the mold is closed. That is, the inclination angle of the lower portion of the lower mold 22 with respect to the stepped portion 22a with respect to the vertical direction (the opposing direction of the upper mold 21 and the lower mold 22) is θ1.

[Second press machine]
The second press device 19 presses the intermediate molded product 30 which is a product to be molded, and is a part on the other end side (concave ridge line portion 34a side) of the stepped portion 11a formed on the vertical wall 33a of the intermediate molded product 30. 33a1 (see FIG. 3, FIG. 4 and FIG. 5) has a function of moving the vertical walls 33a, 33b to the opposite side (opposite side) and the opposite side (arrow A direction side in the figure).

  The 2nd press apparatus 19 is comprised including the 2nd metal mold | die 40 and the 2nd moving apparatus 45, as FIG. 9 shows. As shown in FIGS. 8 and 9, the second mold 40 includes an upper mold 41, a lower mold 43, and a holder 42. The upper mold 41 is disposed on the upper side, and the lower mold 43 is disposed on the lower side. The lower mold 43 is urged from below by a spring 46. Then, the second press device 19 moves the upper die 41 to the lower die 43 side by the second moving device 45 in a state in which the intermediate molded product 30 is fitted in the lower die 43, so that two The angles of the flanges 35a and 35b are changed.

  As shown in FIG. 9, when the lower mold 43 is viewed from the longitudinal direction, stepped portions 43 a are formed on both side surfaces of the lower mold 43. Further, on both side surfaces (curved surfaces) of the groove of the upper mold 41, step portions 41a (an example of second step portions) are formed along the step portions 43a. The shape of the stepped portion 43a (41a) (the width in the short direction of the lower mold 43) is equivalent to the shape of the stepped portion 22a (21a) of the first press device 18. Further, the step portion 43a (41a) is formed at a position corresponding to the step portion 22a (22a ') (a position where the step portions 11a and 11a' of the intermediate molded product 30 overlap). As shown in FIG. 9, when viewed from the longitudinal direction of the upper mold 41, the upper mold 41 has a groove width from the bottom of the groove toward the opening side of the groove (from the upper side to the lower side). Continuously widens. When the lower mold 43 is viewed from the longitudinal direction of the lower mold 43, the width of the protruding portion is continuously narrowed from the lower side to the upper side. And the shape of the lower mold | type 43 is made into the shape fitted according to the shape of the groove | channel of the upper mold | type 41 at the time of a mold closing.

  When the second moving device 45 moves the upper mold 41 toward the lower mold 43 with the intermediate molded article 30 fitted in the lower mold 43, the intermediate molded article 30 is pressed and the roof member 1 is molded. It is like that. As the intermediate molded product 30 is molded, the portion 33a1 on the other end side of the step portion 36a in the vertical wall 33a is moved to the side (opposite side) and the opposite side (outside) where the vertical walls 33a and 33b face each other. It has become. For this reason, the inclination angle θ2 with respect to the vertical direction (opposite direction of the upper mold 21 and the lower mold 22) of the lower part of the lower mold 43 relative to the stepped portion 43a is larger than the inclination angle θ1. In addition, since the shape of the groove | channel of the upper mold | type 41 and the shape of the protrusion part of the lower mold | type 43 are as above-mentioned, level | step-difference part 43a, 41a is the top plate 2 side seeing from the transversal direction of the top plate 2. Further, they are inclined so that the facing distance between them becomes larger (the facing width is widened) on the opening side. From another viewpoint, the stepped portions 41a and 41a 'are inclined so that the facing distance between them is larger on the opening side than on the top plate 2 side.

  As described above, the second press device 19 has been described. However, when the second press device 19 is viewed in another way, the following is obtained. That is, the upper die 41 (an example of the second die) has a bottom surface (the second bottom surface) having the same shape as the bottom surface (an example of the first bottom surface) of the upper die 21 of the first press device 18 as viewed from the mold closing direction. 1 example) and a long groove (an example of the second groove) that includes one end connected to both ends of the second bottom surface in the lateral direction and includes side surfaces (an example of the second side surface) that face each other. Has been. The second side surface (at least one of them is referred to as a second curved surface) is curved when viewed from the mold closing direction (opposite direction of the upper mold 41 and the lower mold 43), and corresponds to the first step portion. It is set as the 2nd curved surface in which the 2nd level | step-difference part was formed in the position to do. Further, the angle θ2 at which the portion on the other end side with respect to the second step portion on the second curved surface is inclined with respect to the mold closing direction is such that the portion on the other end side with respect to the first step portion on the first curved surface is mold-closed. It is larger than the angle θ1 inclined with respect to the direction. Further, the lower die 43 (second punch) is adapted to fit in the shape of the groove (second groove) when the die is closed. That is, the shape of the lower die 43 (an example of the second punch) is a shape that fits into the groove (second groove) when the die is closed.

  The above is the description of the configuration of the press device 17 of the present embodiment.

<Manufacturing method of roof member>
Next, the manufacturing method of the roof member 1 of this embodiment is demonstrated, referring drawings. The method for manufacturing the roof member 1 of the present embodiment is performed using the press device 17. The method for manufacturing the roof member 1 of the present embodiment includes a step (first step) performed by the first press device 18 and a step (second step) performed by the second press device 19.

[First step]
In the first step, the blank 25 is disposed in the gap between the upper mold 21 and the lower mold 22. Next, when the operator operates the first press device 18, the upper die 21 is moved to the lower die 22 side by the first moving device, and the blank 25 is press-formed by drawing. That is, in the first step, the blank 25 that is an object to be molded is pressed using the upper mold 21 and the lower mold 22. As a result, the intermediate molded product 30 is formed from the blank 25. And the intermediate molded product 30 is removed from the 1st metal mold | die 20, and a 1st process is complete | finished.

[Second step]
Next, the intermediate molded product 30 is fitted into the lower mold 43 of the second mold 40 of the second press device 19. And when an operator operates the 2nd press apparatus 19, the upper mold | type 41 will be moved to the lower mold | type 43 side with a 2nd moving apparatus, and the intermediate molded product 30 will be pressed. That is, in the second step, the blank 25 formed in the first step is pressed using the upper die 21 and the lower die 22. As a result, the roof member 1 is molded from the intermediate molded product 30. And the roof member 1 is removed from the 2nd metal mold | die 40, and a 2nd process is complete | finished. Accordingly, the method for manufacturing the roof member 1 of the present embodiment is completed.

  The above is the description of the method for manufacturing the roof member 1 of the present embodiment.

<Action>
Next, the operation of the present embodiment will be described in comparison with a comparative embodiment (not shown) described later. In the description of the comparative embodiment, when the same parts as the parts used in the present embodiment are used, the reference numerals of the parts are used as they are even when not shown. The roof member 1 (not shown) of the comparative form corresponds to a comparative example 5 in a comparative example described later (see FIG. 9).

  In the case of the comparative form, the blank member 25 is pressed by the second press device 19 to form the roof member. Except for this point, the comparative form is the same as the present embodiment.

  According to the evaluation results for the comparative form (Comparative Example 5), as shown in the table of FIG. 14, the tip end bending is 4.38 (mm), the rear end bending is 5.85 (mm), and the average bending amount. Was 5.12 (mm).

  Here, the evaluation of the bending of the front end and the bending of the rear end is based on the roof member data created by the simulation based on the manufacturing method of the roof member of the comparative form with respect to the design data and the manufacturing method of the roof member of the present embodiment. The data of the roof member 1 created by simulation was compared. Specifically, using a computer (not shown), the cross section of the central portion in the longitudinal direction of the top plate 2 is matched (best fit), and the measurement is performed with respect to the center position of the front end (rear end) in the design data. The deviation amount in the width direction of the center position of the front end portion (rear end portion) of the obtained data is defined as the bend, and the average value of the front end bend value and the rear end bend value is defined as the average bend amount (see FIG. 10). ).

  On the other hand, according to the evaluation of this embodiment (Example 9), as shown in the table of FIG. 14, the bending of the tip of the roof member 1 created by the simulation based on the manufacture of the roof member of this embodiment is performed. 5.02 (mm), rear end bending was 4.34 (mm), and average bending amount was 4.68 (mm). That is, in this embodiment, it can be said that the occurrence of bending of the top plate 2 in the short direction due to the spring back is suppressed as compared with the comparative embodiment.

  As described above, in the case of the present embodiment, the reason why the occurrence of bending as viewed from the top plate 2 side is suppressed as compared to the case of the comparative form is presumed as follows. That is, in the case of the comparative embodiment, as described above, the blank 25 is pressed by the second pressing device 19 to form the roof member. When viewed from the top plate 2 side, the vertical wall 4a of the roof member is a curved surface that curves in a convex shape on the side opposite to the side facing the vertical wall 4b. The vertical wall 4b is inclined with respect to the vertical direction (the thickness direction of the top plate 2). Therefore, in the case of the comparative embodiment, when the roof member is press-molded and removed from the second mold 40, compressive stress acts on the outer surface of the vertical wall 4a in the longitudinal direction of the top plate 2. In particular, a portion 4a1 (see FIGS. 1 and 2) of the vertical wall 4a that is closer to the concave ridge line portion 5a than the step portion 11a is a portion 4a2 that is closer to the convex ridge line portion 3a than the step portion 11a of the vertical wall 4a (see FIGS. 1 and 2). Compared with FIG. 2), it is far from the convex ridgeline portion 3a. Therefore, the outer surface of the portion 4a1 has a larger compressive stress acting in the longitudinal direction of the top plate 2 than the outer surface of the portion 4a2. From the above results, it is presumed that the roof member of the comparative form was bent as viewed from the top plate 2 side. On the other hand, in the case of the present embodiment, in the second step, a portion 33a1 (on the concave ridge line portion 34a side) 33a1 (FIG. 3, FIG. 4 and 5) is moved to the opposite side (opposite side) of the vertical walls 33a and 33b (opposite side) and becomes the portion 4a1 (see FIG. 5). Therefore, this embodiment will be in the state where the compressive stress concerning the longitudinal direction of the part 4a1 was reduced compared with the comparison form. As a result, in the case of this embodiment, compared to the case of the comparative embodiment, the target shape (bent tolerance) is likely to occur after the outer surface of the portion 4a1 is bent by compressive stress.

  Therefore, according to the present embodiment, in the second step, the vertical wall 33a of the intermediate molded product 30 is placed on the opposite side (opposite side) where the vertical walls 33a and 33b face each other (the arrow A direction side in the figure). As compared with the case where the top plate 2 is not moved, the bending of the top plate 2 in the short direction due to the spring back is suppressed. In the case of the present embodiment, the spring 33 moves the portion 33a1 of the vertical wall 4a away from the convex ridge line portion 3a to the side opposite to the side (opposite side) where the vertical walls 33a and 33b face each other in the second step. The effect of suppressing the occurrence of bending of the top plate 2 in the short direction due to the back becomes more remarkable.

  The above is description about the effect | action of this embodiment.

<< Second Embodiment >>
Next, a second embodiment will be described. First, the configuration of the roof member 1A (see FIGS. 11 and 12) of the present embodiment will be described. Next, the configuration of the press device (not shown) of this embodiment will be described. Next, a method for manufacturing the roof member 1A of the present embodiment will be described. Next, the operation of this embodiment will be described. In the following description, portions of the present embodiment that are different from the first embodiment will be described.

<Configuration of roof member>
First, the configuration of the roof member 1A of the present embodiment will be described with reference to the drawings. Here, the roof member 1A is an example of a press-formed product and a specific press-formed product.

  The roof member 1A (see FIGS. 11 and 12) of the present embodiment does not include the flanges 6a and 6b (FIGS. 1 and 2). Except for this point, the roof member 1A of the present embodiment has the same configuration as the roof member 1 of the first embodiment.

<Configuration of press machine>
Next, the press apparatus of this embodiment is demonstrated. The press apparatus of this embodiment is for manufacturing the roof member 1A.

  Unlike the 1st press apparatus 18 of 1st Embodiment, the 1st press apparatus of this embodiment is not provided with the holders 23 and 24 (FIG.6 and FIG.7). The 1st press apparatus of this embodiment is set as the structure similar to the press apparatus 17 of 1st Embodiment except this point. Further, the intermediate molded product molded by the first pressing device is the first embodiment except that the two flanges 35a and 35b (FIGS. 3 and 4) of the intermediate molded product 30 of the first embodiment are not provided. The intermediate molded product 30 has the same configuration. That is, the intermediate molded product of this embodiment is a groove-shaped member as viewed from the longitudinal direction of the top plate 2.

<Manufacturing method of roof member>
Next, a method for manufacturing the roof member 1A of the present embodiment will be described. The manufacturing method of the roof member 1A of the present embodiment is the same as that of the first embodiment except that the first press device of the present embodiment is used instead of the first press device 18 of the first embodiment. In the case of this embodiment, the blank 25 is press-molded by bending in the first step to form an intermediate molded product, and the intermediate molded product is press-formed by bending in the second step to form the roof member 1A. Molded.

<Action>
The operation of this embodiment is the same as that of the first embodiment (see the table in FIG. 15 described later).

  The above is the description of the second embodiment.

<Example>
Next, simulations of examples and comparative examples will be described with reference to the drawings. In addition, in the following description, when the code | symbol of components etc. similar to the code | symbol of components etc. used by this embodiment and the comparison form is used, the code | symbol of the components etc. is used as it is.

  In this simulation, as shown in the table of FIG. 14, the roof member 1 (Examples 1 to 19) created by the simulation based on the roof member manufacturing method of the first embodiment and the roof member of the comparative embodiment described above are used. About the roof member (Comparative Examples 1-6) created by the simulation based on a manufacturing method, the bending and average bending amount in the one end 1a and the other end 1b were evaluated. Further, in this simulation, as shown in the table of FIG. 15, the roof member 1 (Examples 20 to 37) created by the simulation based on the roof member manufacturing method of the second embodiment and the roof of the above-described comparative embodiment. About the roof member (Comparative Examples 7-12) created by the simulation based on the manufacturing method of a member, the bending and average bending amount in the one end 1a and the other end 1b were evaluated.

[Description of Table in FIG. 14]
The table of FIG. 14 describes the simulation conditions and evaluation results for Examples 1 to 19 (hat shape) and Comparative Examples 1 to 6 (hat shape). Here, the table of FIG. 14 will be described. The plate thickness is the thickness of the blank 25 used in the simulation. The strength is the tensile strength of the blank 25 used for the simulation. The outer vertical wall change start point (%) is the position in the height direction of the other end (the end connected to the concave ridge line portion 34a) of the portion 33a1 with the convex portion 11a2 of the intermediate molded product 30 as a reference (0%). The start position of the portion 33a1 in the case of 100% is shown. For example, FIG. 13 shows a case where the outer vertical wall change start point is 50%. Further, “−” as the outer vertical wall change start point (%) means that there is no change start point in the first place, that is, the portion 33a1 is not moved in the second step. The inner vertical wall change start point (%) is the other end of the portion 33b1 (see FIG. 13) below the convex portion 11a′2 with the convex portion 11a′2 of the intermediate molded product 30 as a reference (0%). The start position of the part 33b1 when the position in the height direction of (the end connected to the concave ridge line part 34b) is 100% is shown. For example, FIG. 13 shows a case where the inner vertical wall change start point is 50%. The inner vertical wall change start point (%) of “−” means that there is no change start point in the first place, that is, the portion 33b1 is not moved in the second step. Therefore, in order to mold the roof member 1 in FIG. 13, only the second press device (not shown) is different from the second press device 19 of the press device 17 of the first embodiment. Specifically, in the second press device, at least a part of the second step portion of the second curved surface of the second die cross section projected on the cross section of the first die is at least part of the second die section. It is set as the structure which exists in the outer side compared with the part of the other end side rather than the said 1st level | step-difference part in a said 1st curved surface. In other words, the second press device presses the intermediate molded product 30 that is the product to be molded, and the other end side (concave ridge line portion 34b side) of the stepped portion 11a ′ formed on the vertical wall 33b of the intermediate molded product 30. Part 33b1 (refer to FIG. 13) has a function of moving the vertical walls 33a and 33b to the opposite side (opposite side) and the opposite side (arrow A direction side in the figure).

  The roof members of Comparative Examples 1 to 4 are examples of the above-described comparative form. The roof members of Examples 1 to 19 are examples of the roof member 1 of the first embodiment.

[Evaluation results and discussion]
From the table of FIG. 14, the roof member of the example is less bent than the comparative example (the amount of bending is smaller than the comparative example) in the case of the same plate thickness and strength conditions as compared with the roof member of the comparative example. ) For example, when Example 1 and Comparative Example 1 are compared, and Example 3 and Comparative Example 2 are compared, the bending of the Example is smaller (the amount of bending is smaller) than the Comparative Example. That is, these examples are considered to have the effects of the first embodiment.

  Further, when Example 14 and Comparative Example 5 are compared, the bending of Example 14 is smaller than that of Comparative Example 5 (the amount of bending is small). In Example 14, a portion 33b1 lower than the stepped portion 11a 'in the vertical wall 4b different from the first and second embodiments is placed in a direction opposite to the facing direction of the vertical walls 33a and 33b (in FIG. 13). It is moved in the direction opposite to the direction of arrow A). The vertical wall 4b is a curved surface that is concavely curved on the side opposite to the side facing the vertical wall 4b when viewed from the top plate 2. Then, in the case of the roof member of Example 14, compared to Comparative Example 5, in the case of the roof member of Examples 5 and 9, compared to Comparative Example 5, the outer surface of the moved portion 33b1 is bent by a tensile stress. It is considered that the target shape (bend tolerance) is likely to be obtained later.

[Description of Table in FIG. 15]
In the table of FIG. 14, simulation conditions and evaluation results for Examples 20 to 37 (groove shape) and Comparative Examples 7 to 12 (groove shape) are described.

  The roof members of Comparative Examples 7 to 12 are examples of the above-described comparative form. The roof members of Examples 20 to 37 are examples of the roof member 1 of the first embodiment.

[Evaluation results and discussion]
From the table of FIG. 15, the roof member of the example is less bent than the comparative example (the amount of bending is smaller than the comparative example) in the case of the same plate thickness and strength conditions as compared to the roof member of the comparative example. ) For example, when Example 20 and Comparative Example 7 are compared and Example 21 and Comparative Example 8 are compared, the bending of the Example is smaller (the amount of bending is smaller) than the Comparative Example. That is, these examples are considered to have the effects of the second embodiment.

  Moreover, when Example 31 and Comparative Example 11 are compared, the bending of Example 31 is smaller than that of Comparative Example 11 (the amount of bending is small). In Example 31, a portion 33b1 lower than the stepped portion 11a ′ in the vertical wall 4b different from the first embodiment and the second embodiment is placed in a direction opposite to the facing direction of the vertical walls 33a and 33b (in FIG. 13). It is moved in the direction opposite to the direction of arrow A). The vertical wall 4b is a curved surface that is concavely curved on the side opposite to the side facing the vertical wall 4b when viewed from the top plate 2. And, in the case of the roof member of Example 31, it is considered that the target shape (bend allowable value) is likely to be obtained after bending due to the tensile stress acting on the outer surface of the moved portion 33b1 as compared with Comparative Example 11. .

  The above is the description of the embodiment.

  As described above, the present invention has been described with respect to specific embodiments. However, the technical scope of the present invention includes forms other than the above-described embodiments. For example, the following forms are also included in the technical scope of the present invention.

  In each embodiment and example, an example of a press-formed product is described as a roof member. However, if the intermediate molded product is manufactured by including the step of pressing the intermediate molded product and moving the portion on the other end side of the curved wall to the opposite side from the stepped portion, the press molded product is a roof member. Other automotive parts may be used. Further, if the product includes a step of pressing the intermediate molded product and moving the portion on the other end side with respect to the stepped portion of the curved wall to the opposite side, it is a component other than an automotive component. Also good.

  In each embodiment and example, the vertical walls 4a and 4b have been described as being curved walls. However, any one of the vertical walls 4a and 4b is a curved wall, and the intermediate molded product is pressed to move the other end side portion of the curved wall to the opposite side from the stepped portion. The other vertical walls 4a and 4b may not be curved walls as long as they are molded. For example, the other vertical walls 4a and 4b may be straight walls along the longitudinal direction.

1 Roof member (example of press-formed product)
2 Top plate 3a, 3b Convex ridge part 4a, 4b Vertical wall (an example of a curved wall)
17 Press device 18 First press device 19 Second press device 25 Blank 30 Intermediate molded product step part 36a, 36a ′

Claims (6)

The long top plate, the ridge line portions at both ends in the short direction of the top plate, and the respective one ends facing each other in a state of being connected to the ridge line portion, and at least one is curved as viewed from above the top plate A method for producing a press-formed product comprising a pair of vertical walls and a curved wall,
A curved wall in which a blank is pressed and the top plate, the ridge line portions at both ends, and each end face each other in a state of being connected to the ridge line portion, and at least one is curved as viewed from above the top plate An intermediate portion formed on the curved wall along the longitudinal direction of the top plate, the stepped portion projecting to the opposite side and the opposite side of the vertical wall. A first step of molding a molded product;
A second step of pressing the intermediate molded product and moving a portion on the other end side of the curved wall to the opposite side of the stepped portion;
A method for manufacturing a press-formed product including: In the first step, with the position of the top plate as a reference, the stepped portion is formed in a portion of the curved wall that is separated by 40% or more of the height from the top plate to the lower end of the curved wall.
The method for producing a press-formed product according to claim 1. In the first step, the stepped portion is formed such that the protruding width of the stepped portion is 20% or less of the width in the short direction of the top plate.
A method for producing a press-formed product according to claim 2. A curved wall in which a blank is pressed and the top plate, the ridge line portions at both ends, and each end face each other in a state of being connected to the ridge line portion, and at least one is curved as viewed from above the top plate A first press device for forming an intermediate molded product formed on a pair of vertical walls,
A second press device that presses the intermediate molded product and moves a portion on the other end side of the stepped portion of the curved wall to the opposite side to the opposite side;
Press device. A first press device that presses a blank with a first die and a first punch to form an intermediate molded product, and a second press device that presses the intermediate molded product with a second die and a second punch are provided. A pressing device,
The first die has a long first bottom surface, and a long first bottom surface including a first side surface in which one end is connected to an end portion of the first bottom surface in the short direction and faces each other. Grooves are formed,
At least one of the first side surfaces is curved as viewed from the mold closing direction, and a first curved surface is formed with a first step portion that extends the opposing width of the first side surface along the longitudinal direction of the first side surface. And
The shape of the first punch is a shape that fits with the shape of the first groove when the mold is closed.
A first press device;
The second die includes a long second bottom surface, and a long second bottom surface including a second side surface in which each end is connected to an end portion in the short direction of the second bottom surface and faces each other. Grooves are formed,
At least one of the second side surfaces is a second curved surface that is curved when viewed from the mold closing direction, and a second stepped portion is formed at a position corresponding to the first stepped portion,
The angle at which the portion on the other end side of the second curved surface in the second curved surface is inclined with respect to the mold closing direction is the portion on the other end side of the first curved surface in the first curved surface. Larger than the angle inclined with respect to the mold closing direction,
The shape of the second punch is a shape that fits with the shape of the second groove when the mold is closed.
A second pressing device;
Press device. A first press device that presses a blank with a first die and a first punch to form an intermediate molded product, and a second press device that presses the intermediate molded product with a second die and a second punch are provided. A pressing device,
The first die has a long first bottom surface, and a long first bottom surface including a first side surface in which one end is connected to an end portion of the first bottom surface in the short direction and faces each other. Grooves are formed,
At least one of the first side surfaces is curved as viewed from the mold closing direction, and a first curved surface is formed with a first step portion that extends the opposing width of the first side surface along the longitudinal direction of the first side surface. And
The shape of the first punch is a shape that fits with the shape of the first groove when the mold is closed.
A first press device;
The second die includes a long second bottom surface, and a long second bottom surface including a second side surface in which each end is connected to an end portion in the short direction of the second bottom surface and faces each other. Grooves are formed,
At least one of the second side surfaces is a second curved surface that is curved when viewed from the mold closing direction, and a second stepped portion is formed at a position corresponding to the first stepped portion,
At least a part of the second step portion of the second curved surface of the second die projected onto the cross section of the first die is located on the other end side of the second curved surface of the first die. It is outside compared to the part on the other end side,
The shape of the second punch is a shape that fits with the shape of the second groove when the mold is closed.
A second pressing device;
Press device.