WO2019138684A1

WO2019138684A1 - Blank material, method for press molding blank material, and press molding device

Info

Publication number: WO2019138684A1
Application number: PCT/JP2018/042147
Authority: WO
Inventors: 前田真吾; 石原好光; 伊藤康裕; 根本直也; 狩野貴之; 蔭山直佑
Original assignee: 本田技研工業株式会社
Priority date: 2018-01-11
Filing date: 2018-11-14
Publication date: 2019-07-18
Also published as: CN111565864A; JP7000459B2; JPWO2019138684A1; CN111565864B; US20200391271A1

Abstract

A molding recessed part (58) of a lower mold (48) constituting a press molding device (10) is provided with a first blank holder (52), and a circular second blank holder (54) is freely movably provided on one outer peripheral side of the first blank holder (52). Meanwhile, of first and second blank holes (32, 34) opened in blank material (14), straight-line parts (40a, 40b) of the second blank hole (34) have formed therein a pair of tensile force adjusting parts (42a, 42b), and arched parts (44a, 44b) of first and second opening parts (36, 38) are mounted on the second blank holder (54). Furthermore, when draw forming of the blank material (14) is performed, the tensile force imparted to the straight-line parts (40a, 40b) to the outside is adjusted by the tensile force adjusting parts (42a, 42b), and the tensile force imparted to the arched parts (44a, 44b) to the outside in the radial direction is adjusted by the second blank holder (54).

Description

Blank material, press forming method of the blank material and press forming apparatus

The present invention relates to a blank having an opening, a press forming method for drawing the blank and a press forming apparatus therefor.

Conventionally, for example, the side panel of an automobile is produced by press forming a metal plate material, and the side panel is formed by deep drawing, and the entire periphery of the side panel formed in advance and the same is similarly formed. The entire periphery of the opening edge is held by a blank holder to perform deep drawing.

In recent years, in order to improve the design of an automobile, for example, one in which the upper portion of a rear wheel arch in a side panel is formed to be convex by deep drawing is known. When deep drawing such a side panel from a single plate material, particularly in the opening for the rear door which is formed in advance on the rear wheel arch side, a straight portion which is a portion close to the convex shape of the upper portion of the rear wheel arch at this opening Is a location where tension is required because the amount of material inflowing to the convex shape of the rear wheel arch upper part is large during forming and wrinkles easily occur.

Further, in the opening for the rear door, the R portion in the vertical direction is a portion which is stretched by the inflow of the material and a crack is easily generated, and therefore, it is required to reduce the amount of elongation of the material. Therefore, different correspondences are required between the R site and the linear site at the opening. There is also a method in which the rear foil arch and the side panel are separately formed separately and joined by welding or the like, but in this case there is a problem that the manufacturing process increases and the manufacturing cost increases.

For example, in the press forming method disclosed in Japanese Patent No. 3814711, when forming a recess from a metal plate material, a slit is formed in advance along the entire inner circumference of a portion to be scraped in a formed product. When drawing is performed, a force acts only on the outer side of the slit, so that it is possible to perform molding without causing a crack or the like at the end of the slit.

However, in the above-described press forming method, the recess is drawn so as to place the bead only on the central portion inside portion of one side of the scraped portion, and tension is applied to the linear portion requiring tension. There is a problem of difficulty.

Further, in the press forming apparatus disclosed in Japanese Utility Model Application Laid-Open No. 63-145519, a storage groove is formed at a position in the vicinity of the blank holder disposed on the outer peripheral side in the punch serving as the lower mold. Is vertically movable via a cylinder. Then, with the work placed on the upper surface of the punch, the die descends from above and the outer edge of the work is held by the die and the blank holder, and then the die descends and contacts the floating punch Thus, while holding the workpiece, drawing of the workpiece is performed between the die and the lower die.

The present invention is made in connection with the above-mentioned proposal, and in drawing for a blank material having an opening, it is possible to obtain high-quality molded articles while preventing the occurrence of cracks in the opening. It is an object of the present invention to provide a blank material, a press forming method and a press forming apparatus for the blank material.

In order to achieve the above object, the present invention is a blank material which is subjected to draw forming by a press forming device and becomes an automobile body panel,
An opening portion comprising an arc portion provided in the vertical direction in the body panel and a substantially linear connection portion provided in the front-rear direction of the body panel substantially orthogonal to the arc portion and connected to the arc portion;
The connection portion is characterized by being provided with a tension adjustment portion which extends toward the inside of the opening and is capable of adjusting the tension applied toward the outside at the time of molding.

According to the present invention, in a blank material subjected to draw forming by a press forming device, a substantially linear connection is provided between an arc portion provided in the vertical direction of the body panel and an arc portion provided in the front and rear direction of the body panel. A tension adjustment part extending toward the inside of the opening is provided in the connection part, and the tension applied to the connection outside is adjusted when drawing is performed. It is possible.

Therefore, even when deep drawing is performed with a blank material having an opening, the inflow to the outside of the substantially linear connection is suitably adjusted with respect to the arc, thereby making the front and back of the opening It is possible to obtain high quality molded articles by preventing the occurrence of wrinkles on convex molded parts provided in the direction.

In addition, in order to prevent the occurrence of wrinkles due to the inflow of the material to the convex shape of the rear wheel arch upper portion at the time of molding, it is preferable to form a tension adjustment portion for each pair of connection portions. As a result, since tension can be applied by gripping the tension adjustment unit with the (first and second) blank holders of the press forming apparatus, it is possible to prevent the occurrence of wrinkles.

Furthermore, in the opening for the rear door, in order to prevent the generation of cracks due to the inflow of material of the arc portion (R portion), the arc portion is smaller than the forming arc portion of the molded body having the arc portion formed therein It is good to form in the near shape. This makes it possible to reduce the amount of elongation of the material in the arc portion and to prevent the occurrence of cracks.

Furthermore, the present invention is a press-forming method of subjecting a blank material having an opening portion consisting of an arc portion and a substantially linear connection portion connected to the arc portion to draw forming.
The periphery of the opening is pressed and held by the first blank holder provided in the lower mold and the upper mold, and
Pressurize the arc part which becomes the outside to the sandwiching part of the blank held by the first blank holder and the upper die between the second blank holder provided on the outer side of the first blank holder and the upper die It is characterized by holding.

According to the present invention, when drawing a blank material having an opening, the periphery of the opening is pressed and held between the first blank holder provided in the lower mold and the upper mold, and An arc portion of an opening which is an outer side with respect to a holding portion of a blank held by the first blank holder and the upper die, between a second blank holder provided on the outer side of the first blank holder and the upper die Pressurize with and hold.

Therefore, while the peripheral edge of the opening is held between the upper mold and the first blank holder, the second blank holder provided on the outer side holds the arc portion which is the outside of the holding portion between the upper mold and the upper mold It becomes possible.

As a result, by forming the opening so that the arc portion is on the outside of the first blank holder, the amount of inflow to the outside at the time of molding is suppressed to prevent the occurrence of cracks, while the second blank holder reliably It becomes possible to perform draw forming.

Furthermore, it is preferable to form a bead by sandwiching the tension adjustment portion extending from the connection portion toward the inside of the opening portion by the upper mold and the first blank holder. This makes it possible to more effectively apply tension to the blank material.

Further, the present invention is a press forming apparatus which performs draw forming on a blank material having an opening portion formed of an arc portion and a substantially linear connection portion connected to the arc portion,
Upper type,
A lower die arranged to face the upper die and having a mounting surface on which the blank material is placed;
A first blank holder disposed opposite to the upper mold and sandwiching the peripheral edge of the opening in the blank material with the upper mold;
A second blank holder disposed on the outside of the first blank holder and sandwiching an arc part, which is the outside of the sandwiching part of the blank held by the first blank holder and the upper die, with the upper die;
Equipped with
The first blank holder and the upper mold are characterized in that they are provided with a bead for pressing and sandwiching a tension adjustment part extending inward from the connection part of the blank material.

According to the present invention, in a press forming apparatus for draw forming a blank material having an opening composed of a circular arc part and a connecting part, the first mold faces the upper mold and holds the periphery of the opening in the blank together with the upper mold. A blank holder and a second blank holder disposed outside the first blank holder, the second blank holder being outside the holding portion of the blank held by the first blank holder and the upper die The arc portion is formed so as to be nipped between the upper mold and the upper mold.

Therefore, when drawing the blank material, while adjusting suitably the tension applied to the connection part at the opening by the bead of the tension adjustment part at the same time, the second blank holder is used as the second blank holder. By sandwiching it, it is possible to adjust the tension to the outside.

As a result, when drawing is performed on a blank material having an opening, tension adjustment of the connection portion in which cracking is not easily generated even if the inflowing amount of the blank material is large, and if the inflowing amount increases, generation of cracks By making the tension adjustment of the easy-to-use circular arc suitably compatible, it is possible to obtain a deep high-quality molded article with a narrowing while preventing the occurrence of wrinkles at the connection peripheral edge and cracking at the peripheral edge of the circular arc during molding. It becomes.

Furthermore, the second blank holder may be formed annularly. As a result, the tension adjustment portion in the connection portion is gripped by the second blank holder, and tension can be applied more effectively.

Furthermore, the bead may be extended along a direction substantially orthogonal to the extension direction of the tension adjustment portion. Thereby, tension can be uniformly applied to the blank material.

It is a front view of the side outer panel for cars formed by the press forming device concerning an embodiment of the invention. It is a front view which shows the blank material before the side outer panel of FIG. 1 is shape | molded. It is an enlarged plan view which shows the 2nd blank hole vicinity of the fabricated blank material. It is a top view of the lower mold and the 1st and 2nd blank holders which constitute a press-forming device. It is an enlarged plan view of the 2nd holder part of the 1st blank holder shown in Drawing 4, and the 2nd blank holder. FIG. 6 is a cross-sectional view taken along the line VI-VI of FIG. 5; FIG. 7 is a cross-sectional view taken along the line VII-VII of FIG. 5; FIG. 8A is a conceptual view showing a cross-sectional change before and after forming when forming the straight line part of FIG. 2, and FIG. 8B compares the arc part before forming in FIG. 2 with the forming arc part after forming It is a conceptual diagram for.

The press forming apparatus 10 is for applying press forming to the blank material 14, and here, a steel plate which makes the side outer panel (body panel) 12 for a car by the press forming apparatus 10 as the blank material 14 The case where it shape | molds from is demonstrated.

First, the side outer panel 12 which is a molded article will be described with reference to FIG. The side outer panel 12 constitutes, for example, a side portion of a body in an automobile, and is formed on a front pillar portion 16 formed on the front side (arrow A direction) along the vehicle direction and on the rear side (arrow B direction) , The roof portion 22 connecting the upper ends of the front pillar portion 16, the center pillar portion 20, and the rear pillar portion 18; and A side sill portion 24 connecting the lower end of the portion 16, the center pillar portion 20 and the rear pillar portion 18 is included.

The side outer panel 12 is formed with a first door opening 26 surrounded by the front pillar 16, the center pillar 20, the roof 22 and the side sill 24, and the center pillar 20 and the rear pillar 18, a second door opening 28 surrounded by the roof 22 and the side sill 24 is formed, and a rear side (in the direction of the arrow B) of the second door opening 28 is located above the rear tire (not shown) The rear fender portion 30 is formed in the position shown in FIG.

Next, the blank material 14 to be press-formed will be described with reference to FIGS. 2 and 3.

The blank 14 is, for example, a steel plate or the like having a certain thickness, and is formed in a long piece along the longitudinal direction (arrows A and B) of the vehicle. In addition, the first blank hole 32 which is formed on one end side (the direction of arrow A) of the blank member 14 and becomes the first door opening 26 of the molded product (side outer panel 12), and the other end side (arrow A second blank hole (opening) 34 which is formed in the B direction and which becomes the second door opening 28 of the molded product, and the first blank hole 32 and the second blank hole 34 are in the front-rear direction of the vehicle It is spaced apart by a predetermined distance along (arrows A and B directions).

The first blank hole 32 is formed, for example, in a substantially triangular shape in cross section, while the second blank hole 34 is a substantially oval long in the vertical direction (arrow C direction) substantially orthogonal to the longitudinal direction of the blank 14 Formed in the shape of The second blank hole 34 has a pair of straight portions connecting the first and

second openings

36 and 38 having a semicircular shape in the upper and lower portions, respectively, and the first and

second openings

36 and 38. A connecting

portion

40a, 40b and a pair of

tension adjusting portions

42a, 42b extending inward from the

straight portions

40a, 40b.

The first opening 36 has an arc portion 44a formed upward and curved upward in a circular arc shape, and the second opening 38 is formed downward relative to the first opening 36. The arc portion 44b is curved downward in a circular arc shape, and as shown in FIG. 3, the

arc portions

44a and 44b are only slightly against the molding arc portion 46 of the molded article after molding It is formed to be radially inward.

In other words, the diameter of the

arcs

44a and 44b is smaller than the diameter of the molded arc 46 of the molded product, and one arc 44a is close to the upper molded arc 46, The other arc portion 44 b is formed to be close to the lower formed arc portion 46.

That is, the second blank hole 34 is formed such that the first opening 36 and the second opening 38 face each other in the vertical direction, and one linear portion 40 a and the other linear portion 40 b are in the front-rear direction (arrow A , B) are formed between the first and

second openings

36, 38 so as to face each other.

One linear portion 40a connects one end of the arc portion 44a of the first opening 36 and one end of the arc portion 44b of the second opening 38, and the other linear portion 40b is an arc at the first opening 36 The other end of the portion 44 a is connected to the other end of the arc portion 44 b of the second opening 38.

The

tension adjusting portions

42a and 42b extend inward to each other so as to be substantially orthogonal to the pair of

linear portions

40a and 40b, and are formed with a predetermined width in the vertical direction (the direction of arrow C) It protrudes from 40a and 40b by a predetermined length. In other words, the pair of

tension adjustment portions

42 a and 42 b extend toward the center of the second blank hole 34 so as to approach each other.

Next, a press forming apparatus 10 for performing press forming of the above-described blank material 14 will be described.

The press forming apparatus 10 is for performing so-called draw forming, and as shown in FIGS. 4 to 7, the lower mold 48 as a forming die for deep drawing a work which is the blank material 14; The upper mold 50 is moved closer to or away from the lower mold 48 under the action of a lifting mechanism, and first and second

blank holders

52 and 54 for holding the blank material 14.

The lower mold 48 is a fixed mold fixed to a base or the like (not shown), and its outer edge 56 (see FIGS. 6 and 7) has a convex shape, and has a concave formed concave portion 58 substantially at the center. ing. The upper mold 50 is a movable mold that can be displaced in the vertical direction (in the direction of arrow D in FIGS. 6 and 7), and has a forming protrusion 60 insertable into the forming recess 58 of the lower mold 48. A protrusion 62 is formed on the lower surface of the protrusion 60 at a position facing the top of the first blank holder 52.

When the upper mold 50 and the lower mold 48 are closed, the molding convex portion 60 of the upper mold 50 enters into the molding concave 58 of the lower mold 48, thereby forming a molded article between the two. A cavity having a shape of (side outer panel 12) is formed.

The first blank holder 52 is vertically movably provided in the forming recess 58 of the lower die 48, and forms the first holder portion 64 for forming the vicinity of the first blank hole 32 of the blank 14; And a second holder portion 66 for forming the vicinity of the second blank hole 34. Then, the first and

second holder portions

64, 66 are formed to be separated from each other along the front-rear direction (the arrow A direction) of the lower mold 48 (see FIG. 4).

The first and

second holder portions

64, 66 are supported by a plurality of cushion pins 68 whose lower ends extend from biasing means (not shown), as shown in FIGS. The first blank holder 52 composed of the

second holder portions

64 and 66 is displaced following the forward (lift) and reverse (drop) operations of the cushion pin 68 along the vertical direction (the direction of the arrow D).

Further, the tops of the first and

second holder portions

64 and 66 facing the upper die 50 are formed in a substantially planar shape, and an annular groove 70 is formed on the top of the first holder portion 64 in the vicinity of the outer edge. On the other hand, on the top of the second holder portion 66, a pair of groove portions 72 extending in the substantially vertical direction of the lower mold 48 is formed. Then, when forming the blank 14 between the upper die 50 and the first blank holder 52, the projection 62 (see FIG. 6) of the upper die 50 has the annular groove 70 with the blank 14 interposed therebetween. The bead 74 is formed in the vicinity of the first and second

blank holes

32 and 34 of the blank material 14 by being respectively inserted into the groove portion 72 and the groove portion 72.

The bead 74 formed by the first holder portion 64 is formed in an annular shape corresponding to the annular groove portion 70, and the bead 74 formed by the second holder portion 66 is formed in a linear shape corresponding to the pair of groove portions 72. (See Figure 3).

The second blank holder 54 is annularly formed so as to surround the second holder portion 66 of the first blank holder 52, and a plurality of cylinders 76 are provided at the lower portion and supported by the cylinder rod 78. Further, the molding surface 54a of the second blank holder 54 facing the upper die 50 is formed to be higher from the first blank holder 52 side which is the inner side toward the lower die 48 side which is the outer side in the radial direction.

The second blank holder 54 advances and retracts (lifts) vertically with respect to the lower die 48 as the cylinder rod 78 of the cylinder 76 moves forward (lift) and retracts (drops).

The press forming apparatus 10 according to the embodiment of the present invention is basically configured as described above, and next, a forming method of forming the blank material 14 will be described.

First, the blank material 14 is disposed between the mold-opened lower mold 48 and the upper mold 50. Under the present circumstances, the 1st and 2nd

blank holders

52 and 54 are in the top dead center position which raised most under the energizing action of the cushion pin 68 and the cylinder 76, respectively, and the said blank material 14 is said 1st and 2nd blanks It mounts so that it may contact | abut on the top part (mounting surface) of the

holders

52 and 54. As shown in FIG.

Further, the blank material 14 is placed such that the first blank hole 32 faces the first holder portion 64 of the first blank holder 52, and the

straight portions

40a and 40b of the second blank hole 34 and the

tension adjustment portion

42a, 42b faces the second holder portion 66, and the

arc portions

44a, 44b of the first and

second openings

36, 38 are placed so as to face the second blank holder 54.

Then, in order to perform press molding, the upper mold 50 descends under the driving action of a lift mechanism (not shown) and approaches the lower mold 48, and the molding convex portion 60 of the upper mold 50 forms the lower mold 48. By entering the concave portion 58, the surface of the forming convex portion 60 facing the first blank holder 52 first abuts against and presses the portion of the blank 14 placed on the first blank holder 52. .

As a result, the first blank holder 52 receives a pressing force from the upper die 50 and descends while pressing down the cushion pin 68, and the projecting portion 62 of the upper die 50 causes the blank 14 to be an annular groove of the first holder portion 64. By being pushed into 70, plastic deformation occurs to form an annular bead 74. At the same time, the

tension adjustment portions

42a and 42b of the second blank hole 34 are held between the upper die 50 and the top of the second holder portion 66, as shown in FIG. Two straight beads 74 which are recessed downward are formed in the

portions

42a and 42b. The beads 74 are respectively formed along the width direction of the

tension adjusting portions

42 a and 42 b in the vertical direction of the blank material 14.

When the upper die 50 is further lowered, as shown in FIG. 6, drawing is performed in the vertical direction (the direction of the arrow D) between the outer edge 56 of the forming protrusion 60 and the inner edge of the forming recess 58. Along with this, the inside of the blank material 14 is pulled by a predetermined tension toward the outside where the inside of the blank material 14 becomes the vehicle rear side (arrow B direction). At this time, the

linear portions

40 a and 40 b of the second blank hole 34 have a predetermined tension by the

tension adjusting portions

42 a and 42 b held between the upper die 50 and the first blank holder 52 via the beads 74. Accordingly, the inflow of the blank 14 in the vehicle longitudinal direction (arrows A and B) is adjusted.

Further, as shown in FIG. 8A, in the

straight portions

40a and 40b, the upper mold 50 and the lower mold 48 increase the amount of deformation in the vertical direction (arrow D direction), but the outside of the blank 14 (arrow E Because the amount of inflow in the direction is large, no cracking occurs during molding.

At the same time, with the lowering of the upper die 50, as shown in FIG. 7, the cylinder rod 78 of the cylinder 76 is pushed downward and the second blank holder 54 is pushed down via the blank 14, and the second blank The

arc portions

44 a and 44 b of the first and

second openings

36 and 38 of the hole 34 are held between the second blank holder 54 and pressed to squeeze the molding surface 54 a.

At this time, as shown in FIG. 3, in the first and

second openings

36, 38 in the second blank hole 34, the

arc portions

44a, 44b are formed in the radial direction with respect to the forming arc portion 46 after forming. Since the shape is formed so as to be close to each other, the inflow of the blank material 14 radially outward with respect to the second blank hole 34 becomes small.

Here, a change in the inflow of the blank material 14 at the time of molding in the arc portion 44a of the second blank hole 34 described above will be briefly described with reference to FIG. 8B. In FIG. 8B, a first arc portion taken out of a part of the arc portion 44a before forming is R1, and a forming arc portion 46 obtained by forming the first arc portion R1 by press forming is a second arc portion R2. There is.

As can be understood from FIG. 8B, the length of the first arc portion R1 which is a part of the arc portion 44a is L1, and the first arc portion R1 is formed so as to be pushed outward by a predetermined distance radially outward. It becomes the 2nd circular arc part R2 of the forming circular arc part 46 which was enlarged and formed. The second arc portion R2 has a length L2 longer than the first arc portion R1.

That is, when the inflow of the blank material 14 which is the extrusion distance in the radial direction is F1, the difference between the length L2 of the second arc portion R2 after forming and the length L1 of the first arc portion R1 before forming Becomes L2-L1.

On the other hand, for example, before the forming at a position which is radially inward of the first arc portion R1 so that the inflow to the outside in the radial direction of the blank 14 becomes larger than the first arc portion R1 When three arc parts R1 '(refer to the broken line in FIG. 8B) are set, the inflow amount F2 (distance) larger than the above to form the second arc parts R2 from the third arc parts R1' The difference between the length L1 'of the third arc portion R1' and the length L2 of the second arc portion R2 after molding is L2-L1 '.

Therefore, the length of the second arc portion R2 is larger than the length L2 of the second arc portion R2 when the amount of inflow F1 is greater than the length L2 of the second arc portion R2. The difference from L2 increases by L1-L1 '.

In the arc portion 44a, as shown in FIG. 8B, as the inflow to the radial direction outer side of the blank material 14 at the time of forming becomes larger, a crack is more easily generated at the time of forming. Therefore, it is understood that it is preferable to set the shape of the arc portion before molding so that the inflow is as small as possible with respect to the second arc portion R2 after molding, that is, the separation distance in the radial direction is small. .

In the above description, the arc portion 44a of the first opening 36 has been described, but the same applies to the arc portion 44b of the second opening 38, and therefore detailed description will be omitted.

As described above, when the blank 14 is formed, the tension applied to the

straight portions

40a and 40b of the second blank hole 34 is adjusted by the

tension adjusters

42a and 42b to control the tension in the vehicle longitudinal direction. The second blank holder 54 controls the vertical tension applied to the

arcs

44 a and 44 b of the first and

second openings

36 and 38.

In each of the drawings, the inner edge of the second blank hole 34 is actually given a three-dimensional shape, and in particular, as the forming proceeds, the rear side of the vehicle is actually shown. A tensile force that acts toward the rear side (the direction of arrow B) acts on one of the straight portions 40b that becomes (the direction of arrow B). Due to this tensile force, the blank material 14 is drawn deep in the width direction substantially orthogonal to the vehicle direction, and has a three-dimensional shape from the second door opening 28 to the rear fender portion 30 in the molded product. Can.

Then, when the upper die 50 reaches the bottom dead center where it is fully lowered, the blank member 14 held between the lower die 48, the first and second

blank holders

52 and 54, and the upper die 50 becomes the forming recess 58. And a molded product (side outer panel 12) corresponding to the shape of a cavity formed by the molded convex portion 60 entering the molded concave portion 58.

After that, the upper mold 50 is separated from the lower mold 48 and the first and second

blank holders

52, 54 under the action of a lift mechanism (not shown) to open the mold, and the molded product is removed from the press forming apparatus 10 The press forming of 14 is completed, and the side outer panel 12 which is a molded product is obtained. In addition, it becomes the side outer panel 12 which the 1st and 2nd

door opening parts

26 and 28 opened by trimming with respect to a molded article.

As described above, in the present embodiment, in the press forming apparatus 10 for drawing and forming the blank material 14 having the first and second

blank holes

32 and 34, the first blank is placed in the forming recess 58 of the lower die 48. An annular second blank holder 54 is provided on the outer peripheral side of the holder 52 and the second holder portion 66 of the first blank holder 52 disposed on the vehicle rear side, and the second blank hole 34 has a semicircular cross section. First and

second openings

36, 38, and a pair of

straight portions

40a, 40b connecting the first opening 36 and the second opening 38, and the

straight portions

40a, 40b A pair of

tension adjusting portions

42 a and 42 b extending toward the inside of the second blank hole 34 is provided.

As a result, when drawing the blank material 14, the upper mold 50 and the first blank holder 52 form the bead 74 with the

tension adjusting portions

42 a and 42 b interposed therebetween, whereby the linear portion of the second blank hole 34 is formed. It is possible to suitably adjust the tension applied outward with respect to 40a and 40b. Thereby, even when the inflow in the vehicle longitudinal direction (arrows A and B directions) of the blank material 14 is increased, the convex portion in the vicinity of the rear fender portion 30 in the side outer panel 12 by suitably adjusting the tension. Can be molded without causing wrinkles.

In addition, the

arc portions

44a and 44b of the first and

second openings

36 and 38 in the second blank hole 34 in which cracks easily occur during forming are close in shape and radial direction to the shape of the forming arc 46 after forming. By setting in advance so that it becomes possible, it becomes possible to suppress the inflow to the radial direction outer side of the blank material 14 at the time of molding, and accordingly, it is possible to suppress the deformation (the amount of elongation) after molding. Can be suitably prevented.

Furthermore, even if the second blank holder 54 provided on the outer peripheral side of the first blank holder 52 expands the above-mentioned

arc portion

44a, 44b even when the

arc portion

44a, 44b is enlarged radially outward as described above. By reliably sandwiching between 50 and 50, it is possible to preferably adjust the tension applied radially outward without providing a bead.

In other words, even if the diameter dimensions of the

arc portions

44a and 44b in the first and

second openings

36 and 38 in the second blank hole 34 are increased to be on the outer peripheral side of the first blank holder 52, The second blank holder 54 can securely hold and form.

That is, when performing draw forming on the blank material 14 in the press forming apparatus 10, the tension applied to the outside with respect to the

straight parts

40a and 40b of the second blank hole 34 is a tension adjusting part having the beads 74 respectively The

arc portions

44a and 42b are suitably adjusted, and the

arc portions

44a and 44b are shaped so as to be close to the radial direction with respect to the formed arc portion 46 while preventing generation of cracks while the arc portions 44a are formed. , 44b, the tension to the outside can be adjusted by holding by the second blank holder 54.

As a result, even when deep drawing is performed on the blank material 14 having the opening, even if the inflow amount of the blank material 14 is large, cracks are not easily generated, but wrinkles are easily generated on the surface. Preferably, the tension adjustment of 40b and the tension adjustment of

arc portions

44a and 44b at the first and

second openings

36 and 38 which are elongated as the inflow amount increases and cracks are easily generated. Even if deep drawing is performed, for example, the second door opening 28 is not cracked in the second blank hole 34 of the blank 14 having the

arc portions

44a and 44b and the

straight portions

40a and 40b. It is possible to obtain the side outer panel 12 (molded article) for an automobile which is required to have a deep throttle shape in the width direction of the vehicle from the rear fender portion 30 to the rear fender portion 30.

The blank material, the press forming method and the press forming apparatus for the blank material according to the present invention are not limited to the embodiment described above, and it goes without saying that various configurations can be adopted without departing from the scope of the present invention. It is.

Claims

A blank material which is drawn by a press forming device and becomes an automobile body panel,
An opening comprising a circular arc portion provided in the vertical direction in the body panel, and a substantially linear connection portion provided in the front-rear direction of the body panel substantially orthogonal to the circular arc portion and connected to the circular arc portion Have
The blank material, wherein the connection portion is provided with a tension adjustment portion that extends toward the inside of the opening and is capable of adjusting the tension applied toward the outside during molding.
In the blank material according to claim 1,
The said tension adjustment part is a blank material each formed with respect to a set of said connection parts.
In the blank material according to claim 1 or 2,
The blank member, wherein the arc portion is formed in a shape that is smaller and closer to a forming arc portion of a formed molded body of the arc portion.
A press forming method for drawing a blank material having an opening portion including an arc portion and a substantially linear connection portion connected to the arc portion,
The periphery of the opening is pressed and held by the first blank holder and the upper mold provided in the lower mold, and
A second blank holder provided on an outer side of the first blank holder, and the upper die, the arc portion being an outer side with respect to the sandwiching portion of the blank held by the first blank holder and the upper die; A press molding method in which pressure is applied between and held.
In the press forming method according to claim 4,
The press-forming method of clamping the tension adjustment part extended toward the inner side of the said opening part from the said connection part by the said upper mold | die and a said 1st blank holder, and forming a bead.
A press forming apparatus for drawing and forming a blank material having an opening portion including an arc portion and a substantially linear connection portion connected to the arc portion,
Upper type,
A lower die arranged to face the upper die and having a mounting surface on which the blank material is placed;
A first blank holder disposed opposite to the upper mold and sandwiching the peripheral edge of the opening in the blank with the upper mold;
The arc portion, which is disposed outside the first blank holder and is outside the holding portion of the blank held by the first blank holder and the upper die, is held between the upper die and the upper die. 2 with blank holder,
Equipped with
A press-forming apparatus, wherein the first blank holder and the upper die are provided with a bead that pressurizes and clamps a tension adjustment part extending inward from the connection part of the blank material.
In the press forming apparatus according to claim 6,
The press forming apparatus, wherein the second blank holder is annularly formed.
In the press forming apparatus according to claim 6 or 7,
The press forming device, wherein the bead extends along a direction substantially orthogonal to the extending direction of the tension adjusting portion.