JP2017202499A - Structure and manufacturing method thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a joint particularly useful as a joint member for an automobile structure.SOLUTION: In a structure being an integral molding, the structure comprises a top plate part having a concave part in at least one outer edge part in a plan view, at least one vertical wall part along the outer edge part by bending downward from the outer edge part having the concave part, a lower flange part of extending to the outside from the vertical wall part and at least one projection part being an extension flange of extending above the top plate part on the top plate part.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a structure that has a three-dimensional shape and is particularly suitable for automobile members.

  As a structure of A pillar lower in an automobile in recent years, in order to protect a cabin, many proposals for reinforcement by internal reinforcement have been made.

  Patent Document 1 discloses a technique for increasing the thickness against the load input from the front surface by increasing the thickness of the vehicle front side by the reinforcement inside the A pillar lower.

  However, the thick part by reinforcement is only the front surface, and no consideration is given to the load entering the side sill. In the technique of Patent Document 1, the front surface of the A pillar is resistant to a load load. However, when a large load is applied, the load that enters the side sill increases. Only the side sill joined to the side is subject to significant deformation. Furthermore, weight reduction cannot be expected.

  Patent document 2 devises the structure of the reinforcement inside the A pillar to change the traveling direction of the front wheel in the shape of the A pillar lower when the front wheel moves in the event of a collision, thereby suppressing the front wheel from entering the cabin. The technology is disclosed.

  The technique of Patent Document 2 is effective only when the front wheels are directed in the traveling direction and the width of the front wheels is not too large in the vehicle width direction of the A pillar lower. When the front wheel is directed obliquely or when the front wheel width is wide, it is necessary to receive a load on a wide surface, and thus an effect cannot be expected.

JP 2011-37291 A JP2013-141928A

  In the event of a car collision, the wheels do not necessarily jump into the cabin coaxially with the direction of travel. Therefore, it is also necessary to reinforce the portion away from the A pillar lower, that is, the dash side. In preparation for such a case, a dash cross may be connected to the A pillar lower inner. The dash cloth is joined to the A pillar lower inner by raising the flange. For this reason, there is a problem that when the dash cross is displaced, the joint is easily peeled off.

  An object of this invention is to improve the intensity | strength of the junction part at the time of a collision by providing the structure which can be used as an efficient coupling | bonding of A pillar lower inner and a dash cross.

  As a result of intensive studies by the present inventors, a structure having an A pillar and a joint in the dash cross direction and further having a joint in the side sill direction and capable of transmitting a load is used as the A pillar lower inner. It has been found that the above problems can be solved. The present invention has been made on the basis of the above findings, and the gist thereof is as follows.

  (1) A structure which is an integrally molded product, and is bent downward from a top plate portion including at least one concave portion on the outer edge portion and a part or all of the outer edge portion including the concave portion in plan view. And at least one vertical wall portion along the outer edge portion, a lower flange portion extending outward from the vertical wall portion, and at least one projecting portion extending above the top plate portion on the top plate portion. A structure characterized by that.

  (2) The structure according to (1) above, comprising a steel plate having a tensile strength of 590 MPa or more.

  (3) The structure according to (1) or (2), wherein the protruding portion has an open cross section formed by stretch flange.

  (4) The structure according to any one of (1) to (3), which is used for welding and connecting three or more other parts.

  (5) The structure according to (4), wherein the structure is a joint member for automobile structure.

  (6) A method for producing the structural member according to any one of (1) to (5) above from a molding material that is a flat plate using a press and a press molding apparatus including a die, wherein the molding material is The flat plate portion is formed on the same plane as the molding material by placing between a punch and a die for forming the protruding portion on the molding material and press forming, and at least one protruding portion is provided above the flat plate portion. The first step of forming and forming material forming the protruding portion is disposed between the punch and the die for forming the vertical wall portion and the lower flange portion on the forming material formed with the protruding portion, The second step of forming the vertical wall portion and the lower flange portion by press molding, and the molding material in which the protrusion portion, the vertical wall portion, and the lower flange portion are formed are restructured. , With a punch to shape Disposed between Lee, by press molding, the manufacturing method of the structure, characterized in that it comprises a third step of forming the protrusions.

(7) A method for producing a structural member according to any one of (1) to (5) above from a molding material that is a flat plate, using a punch and a press forming apparatus including a die,
The molding material is arranged between the punch and the die for forming the vertical wall portion and the lower flange portion on the molding material on which the protruding portion is formed, and is press-molded to be flush with the molding material. A first step of forming the vertical wall portion and the lower flange portion, and a punch for forming a protruding portion on the molding material from the molding material formed with the vertical wall portion and the lower flange portion. A molding material in which a second step of forming at least one projecting portion above the flat plate portion, and a projecting portion, a vertical wall portion, and a lower flange portion are disposed between the die and press-molded. Is disposed between a punch and a die for restricting the protruding portion, and press-molded to form a third step of forming the protruding portion.

  (8) A method for producing the structural member according to any one of (1) to (5) above from a molding material that is a flat plate, using a punch and a press molding apparatus provided with a die, The molding material is placed between a punch and a die for molding the protruding portion and press-molded, so that the same plane as the molding material is the flat plate portion, and the protruding portion is at least above the flat plate portion. The first step of forming one and the molding material on which the flange is formed are disposed between the punch and the die for forming the vertical wall portion and the lower flange portion on the molding material on which the protruding portion is formed. And the manufacturing method of the structure characterized by including the 2nd process of forming the said vertical wall part and the said lower flange part by press-molding.

  (9) A method for producing the structural member according to any one of (1) to (5) above from a flat molding material using a punch and a press molding apparatus including a die, wherein the molding material is The flat plate portion is formed in the same plane as the molding material by placing the punching die and the die for forming the vertical wall portion and the lower flange portion on the molding material on which the protruding portion is formed, and press molding. And the first step of forming the vertical wall portion and the lower flange portion and the molding material forming the vertical wall portion and the lower flange portion between the punch and the die for forming the protruding portion on the molding material. And a second step of forming at least one of the protrusions above the flat plate portion by arranging and press forming the structure.

  ADVANTAGE OF THE INVENTION According to this invention, the structure which can be used as an efficient coupling | bonding of A pillar lower inner and a dash cross can be provided. Thereby, the joint strength of A pillar lower and a dash cross can be improved, and the collision-resistant characteristic of a motor vehicle can be improved.

It is a figure which shows the outline of an example of the structure of this invention. It is a figure which shows the outline of the deformation | transformation in case the load load from the front and the junction part of the conventional A pillar lower and a dash cross are applied. It is a figure which shows the outline of a deformation | transformation when the load load from the joining part of a dash cross at the time of using the structure of this invention as an A pillar lower inner, and the front load is applied. It is a figure which shows the general form of the shaping | molding raw material in an example of the manufacturing method of the structure of this invention. It is a figure which shows the general form of the structure after the 1st process in an example of the manufacturing method of the structure of this invention. It is a figure which shows the outline of the metal mold | die structure used at the 1st process in an example of the manufacturing method of the structure of this invention. It is a figure which shows the general form of the structure after the 2nd process in an example of the manufacturing method of the structure of this invention. It is a figure which shows the outline of the metal mold | die structure used at the 2nd process in an example of the manufacturing method of the structure of this invention. It is a figure which shows the general form of the structure after the 3rd process in an example of the manufacturing method of the structure of this invention. It is a figure which shows the outline of the metal mold | die structure used at the 3rd process in an example of the manufacturing method of the structure of this invention.

  Hereinafter, the structure of the present invention will be described in detail by taking as an example the case of use as an A-pillar lower inner of an automobile.

  The A pillar lower is an internal collision compatible part that secures the occupant's living space in the event of a collision.

  The A pillar lowers are respectively located on the rear sides of the left and right front wheels, and the upper ends thereof are connected to A pillar uppers that are columns attached to both sides of the front window. The lower end of the A pillar lower is connected to a pair of left and right side sills that are frames constituting both sides of the vehicle body under the left and right doors.

  The lower ends of the left and right A pillar lowers are connected by a dash cross. The dash cross is provided on a dash panel that extends in the vehicle width direction and partitions the engine room and the vehicle compartment.

  FIG. 1 shows an outline of an example of the structure of the present invention. The structure of the present invention is a structure (10) which is an integrally molded product, and has a protruding portion (12) above the flat plate portion (11), and a concave portion (14) of the flat plate portion (11). The vertical wall portion (15) is bent along the outer edge portion (13) and is formed along the outer edge portion (13), and the lower flange (16) extends outward from the vertical wall portion. Here, the integrally molded product refers to a molded product that does not have a joint portion formed by welding or mechanical bonding.

  In the example of FIG. 1, the flat plate portion (11) is substantially L-shaped in plan view. The protrusion (12) is a flange provided substantially perpendicular to the surface of the flat plate portion (11).

  A lower flange (16) is a flange provided in the surface different from the surface in which the protrusion part (12) was provided. That is, the vertical wall portion (15) is provided along the outer edge portion (13) having the concave portion (14) of the flat plate portion (11), and the lower flange (16) is located outside the vertical wall portion (15). And is substantially L-shaped in plan view. As a result, it can be used as flanges (16a, 16b) extending in two directions when connecting two components that are substantially perpendicular. In the example of FIG. 1, the concave portion (14) has a curved shape and is a concave corner portion with rounded corners, but the shape is not particularly limited as long as it is concave with respect to the flat plate (11).

  The flanges (16a, 16b) extending in these two directions together with the protrusion (12) form a three-dimensional three-way flange, and any of the three flanges (12, 16a, 16b) The two flanges form an angle of about 90 °.

  The protrusion in the present invention may be a tube having an open cross section like the protrusion (12) in the above example, or may be a flat plate like the lower flange (16). Moreover, the tubular shape which has a closed cross section may be sufficient.

  As shown in FIG. 2, the conventional A pillar lower inner (21) is spot welded to an A pillar lower outer (22) in which an A pillar lower reinforcement (27), which is a reinforcing member, is disposed, and a dash cross ( 23), the flange (24) is raised on the dash cross (23), and the A pillar lower inner (21) is joined to the joint (25) by spot welding. That is, the surfaces extending in the front-rear direction of the automobile are joined in the vehicle width direction.

  In the case of such a joint structure, when a load is applied to the dash cross (23) from the front due to a collision or the like, the dash cross (23) is deformed backward (26), and at that time, the joint (25) is peeled off. It becomes easy.

  On the other hand, when the structure of the present invention shown in FIG. 1 is used as the A-pillar lower inner (31), as shown in FIG. 3, the A-pillar is formed by using two substantially L-shaped flanges (13a, 13b). A lower outer (32) and a side sill (not shown) can be joined by spot welding, and a dash cloth (33) can be joined by spot welding to form a joint (34) using the protrusion (12).

  In the case of such a joint structure, when a load load is applied to the dash cloth (33) from the front due to a collision or the like, the dash cloth is deformed rearward (35), but the load applied to the joint portion is a load in the shear direction. Generally, in joint strength such as spot welding, shear strength (TTS) is larger than peel strength (CTS). Therefore, the joint strength is improved and the collision safety can be improved.

  In addition, compared to the conventional joint structure, the joint position is inside the cabin, so the moment generated by the displacement of the dash cross at the time of collision can be made smaller than in the conventional structure, contributing to improved joint strength. To do.

  When the structure of the present invention is used for an automotive member such as an A pillar lower inner, for example, it is preferable to use a high strength steel plate having a tensile strength of 590 MPa or more. By using a high-strength steel plate, further excellent crash resistance can be obtained.

  Next, an example of the manufacturing method of the structure of the present invention will be described.

  The structure of the present invention is manufactured by a “free bending method” in which a blank is press-molded with a press-molding device having a punch, a die, and a pad that presses and restrains a blank (molding material) such as a metal plate against the punch. can do. Hereinafter, the “free bending method” will be briefly described.

  The free bending method is known, for example, in International Publication No. 2011/145679. The invention described in the above publication is a method of forming a part having a bent portion in which the cross section is substantially a hat shape and the vertical wall portion is convex to the top plate portion side in a plan view like a L-shaped member from a blank. is there.

  More specifically, the blank is disposed between the die mold, the pad, and the bending mold, and (1) a part of the portion corresponding to the top plate portion of the blank as an out-of-plane deformation suppression region is pressed by the pad. In a state where the end of the portion corresponding to the lower side of the L-shape of the blank is on the same plane as the top plate portion, the die mold and the bending die are moved relative to each other in the vertical direction. By forming the vertical wall portion and the flange portion while sliding (moving in the plane) the end portion of the portion corresponding to the lower side of the L-shape on the portion corresponding to the top plate portion of the die mold. It is for molding a letter-shaped part or the like.

  Or (2) the pad is brought close to or in contact with a part of the blank corresponding to the top plate portion as the out-of-plane deformation suppressing region, and the gap between the pad and the die mold is not less than the blank plate thickness. The die mold and the bending mold are vertically placed in a state where the thickness is maintained at 1.1 times or less and the end of the portion corresponding to the lower side of the L-shape of the blank is on the same plane as the top plate portion. By moving relative to each other in the direction, the end of the portion corresponding to the lower side of the L-shape of the blank is slid (moved in the plane) on the portion corresponding to the top plate portion of the die die. An L-shaped part or the like is formed by forming the wall portion and the flange portion.

  In this specification, the press working method by bending according to the above invention is referred to as “free bending method”. In the case of manufacturing an integrally molded structure as shown in FIG. 1, for example, a casting method may be considered. However, in the case of the casting method, it is difficult to control the structure, and it may be difficult to obtain the required characteristics. On the other hand, when the free bending method is used, it is advantageous to use a material having desired characteristics because a structure having necessary characteristics can be manufactured. For example, if a high-strength steel plate is used as a material to produce the structure of the present invention and used as a connection member for an automobile, the collision resistance can be remarkably improved. Hereinafter, an example of a specific method for manufacturing the structure of the present invention shown in FIG. 1 will be described.

  The structure shown in FIG. 1 has a protruding portion that is an extending flange extending in a substantially vertical direction, and a lower L-shaped portion that is two flanges that are substantially perpendicular to the protruding portion and intersect at a substantially right angle. The manufacturing method of the structure described below is as follows: (1) Stretch flange molding of the projection for forming the projection, (2) Free bending molding of the lower flange, (3) Projection of the projection by wrist-like. 3 steps are provided, and the structure shown in FIG. 1 can be obtained by molding in the order of (1) → (2) → (3) or (2) → (1) → (3).

  Alternatively, the protrusions can be formed by using a method of forming the protrusions at once without providing a process of preforming the protrusions and then performing re-striking. That is, it comprises two steps of (1 ′) projecting portion molding, (2) free bending molding of the lower L-shape, and molding in the order of (1 ′) → (2) or (2) → (1 ′), The structure shown in FIG. 1 can also be obtained.

  In the stretch flange molding of the projection for forming the projection of (1) above, the surface of the blank (41) shown in FIG. 4 is a flat plate portion, the projection is formed above the projection (51), The formed shape is shown in FIG. In this example, the protrusion is a flange having an open cross section.

  More specifically, as shown in FIG. 6, a flange is formed on a blank (61) using a punch (62) and a die (63). The blank holder (64) holds the blank (61) together with the die (63), adjusts the material flow, and prevents wrinkles. The blank holder (64) does not need to be in close contact with the blank (61), and there may be a gap. A flange can be formed by pressing the blank (61) fixed by the die (63) with the punch (62).

  Next, in the lower L-shaped free bending molding of (2) above, the vertical wall portion (73) and the lower flange (74) along the outer edge portion (72) of the flat plate portion (71) are formed simultaneously, and FIG. The shape of In this example, the vertical wall part (73) and the lower flange (74) along the outer edge part (72) are simultaneously formed on the blank by a free bending method.

  More specifically, as shown in FIG. 8, a flange is formed on a blank (81) using a punch (82) and a die (84). The pad (83) presses and holds the blank (81) against the punch (82). By pressing the fixed blank (81) with the die (84), the vertical wall portion (73) and the lower flange (74) along the outer edge portion (72) are simultaneously formed in the blank.

  7 and 8 show a method of performing free bending molding of the lower flange portion after the stretch flange molding of the projecting portion for forming the projecting portion (1), as described above, The order of the steps 1) and (2) may be reversed.

  Next, in the above-described projecting of the projecting part by the wrist-like (3), the shape of the projecting part formed by the stretch flange is adjusted to obtain the projecting part (91) shape as shown in FIG. FIG. 10 is a diagram showing an example of a mold structure used for wrist-like. The blank (101) is pressed against the die (103) by the pad (104) and gripped, and the blank (101) fixed by the die (103) is pressed by the punch (102) to form the protrusion. In addition, as above-mentioned, the method of shape | molding at a stretch may be used for shaping | molding of a protrusion part instead of carrying out preforming and carrying out the restrike separately after that.

  According to the manufacturing method of the structure of the present invention described above, by using a general press machine, a structure that is particularly useful as a structural joint member can be used in a short operation without using a special device. Can be manufactured in time.

  As mentioned above, although the structure and manufacturing method were demonstrated about the case where the structure of this invention is used as an A pillar lower inner, use of the structure of this invention is not limited to this. The structure of the present invention can be effectively used as a joint particularly when three or more members are joined three-dimensionally.

  As a joint member for automobile structure, for example, it can be used as a joint member at the top of the pillar at the rear of the vehicle, for connection to a roof rail, a pillar at the rear of the vehicle, or a member disposed in the vehicle width direction at the top of the rear window. . If it is a sedan type vehicle, it is a C pillar upper, and if it is a hatchback type vehicle, it corresponds to the upper part of the tailgate. This improves the rigidity of the vehicle and contributes to cabin protection during rollover.

  Moreover, it can be used as a B pillar lower to connect a B pillar, a side sill, and a floor cloth. This contributes to cabin protection during a side collision and improves the torsional rigidity of the vehicle body.

  Also, the three-pronged flange is not limited to the above example. In the above example, any two of the three flanges form an angle of about 90 °. However, for example, any two of the three flanges form an angle of about 60 to 120 °. Even if it shape | molds in this way, the utilization as a coupling member for structures can be considered. Not all flanges need to meet at one point, there may be two flanges in a twisted position.

  In the above example, the flange is trifurcated, but it is also possible to form a four-pronged flange in the same manner. For example, the four-pronged flange has a substantially T-shaped top plate portion, a vertical wall portion and a flange provided along two outer edge portions that are substantially L-shaped, and in the vicinity of the T-shaped intersection of the top plate portion. It can be set as the shape which has the protrusion part which is an elongate flange. Thus, by changing the shape of the punch and die, it is obvious that structures of various shapes can be manufactured without being limited to the above-described joint examples, and those modifications are also within the scope of the present invention. Needless to say, it is included in

  For example, in the above example, an automotive structural joint member using a high-strength steel plate is shown, but other steel plates, aluminum alloy plates, resin composite material flat plates such as FRP, etc. are used as a forming material depending on the application. be able to.

DESCRIPTION OF SYMBOLS 10 Structure 11 Flat part 12 Protruding part 13 Outer edge part 14 Concave part 15 Vertical wall part 16 Lower flange 21 A pillar lower inner 22 A pillar lower outer 23 Dash cross 24 Flange 25 Welding part 26 Deformed cross 27 A pillar lower Reinforce 31 A Pillar Lower Inner 32 A Pillar Lower Outer 33 Dash Cross 34 Welded Part 35 Deformed Cross 36 A Pillar Rear Reinforce 41 Blank 51 Protruding Part 61 Blank 62 Punch 63 Die 64 Blank Holder 71 Flat Plate 72 Outer Edge 73 Vertical Wall 74 Lower flange 81 Blank 82 Punch 83 Pad 84 Die 91 Projection 101 Blank 102 Punch 103 Die 104 Pad

Claims (9)

A structure that is an integrally molded product,
In plan view, the top plate portion including at least one concave portion on the outer edge portion;
At least one vertical wall portion that bends downward from a part or all of the outer edge portion including the concave portion, along the outer edge portion, and
A lower flange portion extending outward from the vertical wall portion;
A structure having at least one protrusion extending above the top plate on the top plate.   The structure according to claim 1, comprising a steel plate having a tensile strength of 590 MPa or more.   The structure according to claim 1, wherein the protrusion has an open cross section formed by stretch flange.   The structure according to any one of claims 1 to 3, which is used for welding connection of other parts of three or more parts.   The structure according to claim 4, wherein the structure is an automobile structural joint member. A method for producing the structural member according to any one of claims 1 to 4, from a molding material that is a flat plate, using a punch and a press molding apparatus including a die,
The molding material is placed between a punch and a die for forming a protruding portion on the molding material, and press-molded so that the same plane as the molding material is the flat plate portion, and the protruding portion is above the flat plate portion. A first step of forming at least one of
The molding material formed with the protrusions is placed between the punch and the die for forming the vertical wall portion and the lower flange portion on the molding material with the protrusions formed, and press-molded, thereby A second step of forming the wall portion and the lower flange portion;
By forming the projecting part, the vertical wall part, and the lower flange part, the projecting part is placed between a punch and a die for reshaking the projecting part and adjusting the shape, and press-molding the projecting part. A structure manufacturing method comprising a third step of forming. A method for producing the structural member according to any one of claims 1 to 4, from a molding material that is a flat plate, using a punch and a press molding apparatus including a die,
The molding material is arranged between the punch and the die for forming the vertical wall portion and the lower flange portion on the molding material on which the protruding portion is formed, and is press-molded to be flush with the molding material. A first step of forming the flat plate portion, and forming the vertical wall portion and the lower flange portion,
The molding material in which the vertical wall portion and the lower flange portion are formed is disposed between a punch and a die for forming the protruding portion on the molding material and press-molded, so that at least one protruding portion is provided above the flat plate portion. A second step of forming one;
A molding material in which a protruding portion, a vertical wall portion, and a lower flange portion are formed is disposed between a punch and a die for restricting the protruding portion, and press-molded to form the protruding portion. The manufacturing method of the structure characterized by including the process of. A method for producing the structural member according to any one of claims 1 to 4, from a molding material that is a flat plate, using a punch and a press molding apparatus including a die,
The molding material is placed between a punch and a die for molding the protruding portion on the molding material, and press-molded, so that the same plane as the molding material is the flat plate portion, and the flat plate portion is located above the flat plate portion. A first step of forming at least one protrusion;
The molding material formed with the flange is placed between the punch and the die for forming the vertical wall portion and the lower flange portion on the molding material formed with the protruding portion, and press-molded, thereby A structure manufacturing method comprising a second step of forming a wall portion and the lower flange portion. A method for producing the structural member according to any one of claims 1 to 4, from a molding material that is a flat plate, using a punch and a press molding apparatus including a die,
The molding material is arranged between the punch and the die for forming the vertical wall portion and the lower flange portion on the molding material on which the protruding portion is formed, and is press-molded to be flush with the molding material. A first step of forming the vertical wall portion and the lower flange portion, and a punch for forming the protruding portion into the molding material using a molding material formed with the vertical wall portion and the lower flange portion. A method of manufacturing a structure, comprising: a second step of forming at least one of the protrusions above the flat plate portion by placing between and a die and press forming.

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