JP2002249070A - Structure for automobile - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a structure for an automobile capable of being easily manufactured even though it has the comparatively large and complex shape. SOLUTION: A center pillar 4 is composed of a pillar structural member 10 and a pillar cover 12. The pillar structural member 20 is made of a die cast and formed into the box shape of which one face is opened, and the opening 11 is covered with the pillar cover 12 to form the center pillar 4 composed of a hollow structure having a closed cross-section. The pillar structural member 10 and the pillar cover 12 are integrally bonded by a frictional stirring bonding or the like.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure for an automobile, and more particularly to a comparative structure such as a center pillar for an electric vehicle, a front cross member, a rear cross member, a suspension frame, a side sill, and a member for connecting the same. The present invention relates to an automobile structure suitable for application to a structure having a large and complicated shape.

[0002]

2. Description of the Related Art Vehicle body structures such as pillars (body pillars), front cross members, rear cross members, suspension frames, and the like are usually used in vehicles.
It is manufactured by extrusion of an aluminum material or press molding of a metal plate. In addition, in order to ensure sufficient mechanical strength, the structure is generally a hollow closed-section structure. For example, JP-A-08-026055 and JP-A-09-24
The pillar structure for an automobile described in Japanese Patent No. 0385 discloses a structure in which two columnar frames formed in a convex (trapezoidal) cross-sectional shape in order to increase mechanical strength are arranged such that their opening surfaces are in close contact with each other. By joining the butted portions (flanges) by spot welding, pillars having a hollow closed-section structure are formed.

The vehicle pillar described in Japanese Patent Application Laid-Open No. 2000-118441 has a hollow closed cross-sectional structure made of extruded aluminum material, a central cross-sectional shape of a sun, and upper and lower ends. Has a rectangular cross section.

[0004]

As described above, conventional pillars for automobiles have been manufactured into a hollow closed-section structure by extrusion or press molding. However, when it is manufactured from an extruded shape, it is difficult to technically manufacture a complex shape or a large shape, and it is particularly difficult to form a curved surface that matches the curved shape of the vehicle body during extrusion molding. Therefore, it is necessary to bend into a desired shape, and there is a problem that the shape is restricted.
On the other hand, a structure formed by press-molding a metal plate has a problem in that the mechanical strength is weak, and when reinforced with a reinforcing material, the number of parts and the number of steps of welding work increase accordingly. Also, when members are joined to each other by mechanical joining means such as bolts in both the extruded shape member and the press-formed product made of a metal plate, if the thickness of the joining portion is thin, a large load is concentrated on the joining portion and the joint is broken. There was also a problem.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned conventional problems, and an object of the present invention is to provide an automobile having a relatively large and complicated shape. To provide a structure.

[0006]

According to a first aspect of the present invention, there is provided a box-shaped structural member having at least one open surface, and a cover for covering all or a part of an opening of the structural member. Wherein the structural member is made of die-cast and integrally has a rib inside, and the cover is integrally joined to an opening of the structural member. Things.

[0007] A second invention is the first invention, wherein
The rib is formed so as to be located inside the opening of the structural member by an amount corresponding to the thickness of the cover, and the cover is supported by the rib and forms the same plane as the opening surface of the structural member.

According to a third aspect of the present invention, in the first or second aspect, a positioning projection is provided on one of the structural member and the cover, and a positioning hole is provided on the other. And positioning the cover.

[0009] A fourth aspect of the present invention is directed to the first, second or third aspect.
In the invention, a flange which forms the same surface as the cover is integrally provided on the opening side edge on the surface of the structural member.

According to a fifth aspect of the present invention, in the first, second, third or fourth aspect, the structural member has a rib or web plate thickness just below the joining portion of 1.0 mm or more, and the cover is friction stir welded. Are integrally joined.

According to a sixth aspect, in any one of the first to fourth aspects, the structural member and the cover are integrally joined by a mechanical joining means.

According to a seventh aspect of the present invention, in any one of the first to sixth aspects, the structural member is manufactured by VO die casting.

In the present invention, since the structural member is made of a die-cast casting, a dimensional accuracy is high and a desired shape can be obtained without requiring post-processing. The cover covers the whole or a part of the opening of the structural member, and forms a structure having a hollow closed cross section with the structural member. The positioning projection and the positioning hole position the structural member and the cover.
Friction stir welding is a joining method in which the joint of two members to be joined is softened into a plasticizable state by friction heat and solid-phase joining is performed, so there is little generation of distortion and oxide film, and it is simpler than conventional welding It can be performed quickly and with high bonding strength, and a smooth and beautiful surface can be obtained. As the mechanical joining means, a bolt, a rivet, an adhesive, or a combination thereof is used. The VO die casting method is a type of die casting method in which the interior of the cavity is evacuated to a vacuum, a certain amount of oxygen is supplied and replaced, and then the molten metal is injected into the cavity under pressure and cast. It is.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail based on an embodiment shown in the drawings. FIG. 1 is a perspective view of a monocoque body showing a first embodiment in which the present invention is applied to a center pillar of an automobile, and FIGS. 2A and 2B are an exploded perspective view and a sectional view of the center pillar. In these figures, reference numeral 1 denotes a front pillar, 2 denotes an underbody (side sill), 3 denotes a roof, 4 denotes a center pillar, 5 denotes a rear pillar, 6 denotes a front cross member, and 7 denotes a rear cross member. It constitutes a monocoque body 8 of an automobile.

In FIG. 2, the center pillar 4 is
A vertically closed box-shaped pillar structure member 10 having one surface open parallel to the front-rear direction of the vehicle body, and a hollow closed cross-sectional structure formed by a cover 12 closing an opening 11 of the pillar structure member 10. That is, the inside is formed in a closed hollow body, and the upper end is joined to the roof 3 and the lower end is joined to the underbody 2 by welding or the like. The center pillar 4 has an elongated trapezoidal shape in which the lower end has the largest width in the vehicle front-rear direction and the vehicle width direction, and gradually decreases toward the upper end, and forms an outer surface so as to form the same curved surface as the side surface of the vehicle body. It is convexly curved.

The pillar structural member 10 is made of an aluminum alloy casting manufactured by a die casting method, and includes a front plate portion 13 and a rear plate portion 14 facing the front and rear direction of the vehicle body, and an upper plate facing the vertical direction. Part 15 and bottom plate part 1
6 (hereinafter also referred to as a web) and an inner plate portion 17 forming an inner surface of the vehicle body are integrally formed to form a box shape having an outer surface opened. Are formed integrally with each other. The rib 18 is used for the pillar structural member 1.
The cover 12 is formed so as to be located inside from the opening 11 corresponding to the plate thickness of the cover 12. Side flanges 19 and 2 are provided at the opening side edges of the surfaces of the front plate portion 13 and the rear plate portion 14.
0 protrude integrally from each other. Side flange 1
The surfaces of 9 and 20 form the same plane as the opening 11 of the pillar structural member 10. The thickness of the pillar structural member 10, the ribs 18, and the flanges 19 and 20 is 1 to 5 mm.

The pillar cover 12 is made of a cast product of an aluminum alloy manufactured by die casting or a press-formed product of a metal plate, and is fitted into the opening 11 of the pillar structural member 10 so that the back surface is formed. The rib 18 comes into contact with the distal end surface 18a, and the surface forms the same surface as the surfaces of the side flanges 19 and 20, and is integrally joined by welding or the like.

In the present embodiment, the pillar structural member 10 opened to the side of the vehicle body is shown, but the present invention is not limited to this.
Pillar structural member 1 that opens to the inside of the vehicle body as shown in FIG.
0 ', and the opening 11' of the pillar structural member 10 '
May be covered with a pillar cover 12 ′, and these may be integrally joined by welding or the like to form a center pillar having a hollow closed-section structure.

As a method for joining the pillar structural member 10 (10 ') and the pillar cover 11 (11'), there are MIG welding, laser welding, and friction stir welding (hereinafter, referred to as FSW: Friction Stir Welding).
g), bolts, rivets, adhesives and the like.

When the pillar cover 12 is joined to the pillar structural member 10 by TIG welding, MIG welding, or the like, aluminum has a large thermal expansion coefficient, so that distortion is large and an oxide film is generated.
When it is essential to remove such distortion and oxide film in a later step, the number of steps is increased and a skilled technique is required, which is not preferable.

FSW is a method of joining two members to be joined by abutting or overlapping using frictional heat.
A friction stir probe made of a material such as steel that is harder and more heat-resistant than the member to be joined is rotated at high speed, and a pin provided at the tip of the probe is pressed into the member to be joined, and the member and the probe are joined. By relatively moving along the line, frictional heat is generated at the joint, and the abutting or overlapping part is softened to a state that can be plastically processed by this frictional heat, and the stirring action by the high-speed rotation of the pin causes This is a joining method in which plastic flow is performed and solid-phase joining is performed so as to be integrated (Japanese Patent No. 2712838 and Japanese Patent No. 2792233).

When the pillar structure member 10 and the pillar 12 are joined by the FSW, the pillar cover 12 is fitted into the opening of the pillar structure member 10 as shown in FIG.
And the friction stir probe 21 is rotated at a high speed, and the pin 22 integrally provided at the tip thereof is attached to the pillar cover 12.
Then, the probe 21 may be pushed into the joint 23 with the rib 18 to generate frictional heat and move the probe 21 along the joint line.
The web of the pillar structure 10 (the front plate portion 13, the rear plate portion 14,
And the upper plate portion 15 and the bottom plate portion 16) are joined by abutting the end surfaces of the pillar covers 12 on the inner surface of the web,
The probe 21 may be moved along the joining line by pushing it into the joining portion 23a to generate frictional heat.

Unlike the case of welding by TIG welding or MIG welding, joining by FSW does not require a welding rod or an inert gas, etc., making joining simple and quick. Because the occurrence is small,
No post-process such as distortion correction or oxide film removal is required. In addition, since solid-state bonding is used instead of fusion bonding, there is an advantage that there is little structural change around the solid-state bonding.

As described above, when the center pillar 4 having a hollow closed cross-sectional structure is manufactured by the pillar structural member 10 and the pillar cover 12, bending rigidity, torsional rigidity, bending strength, and the like are obtained.
The torsional strength and the like are large, and the energy absorption performance at the time of a collision can be enhanced. Further, since the pillar structural member 10 is a die-cast cast article, relatively high dimensional accuracy is obtained, and even when the side surface shape of the vehicle body is a curved surface, the pillar structural member 10 can be formed in a shape that matches this shape. Therefore, it is not necessary to bend in the subsequent process so as to coincide with the side surface of the vehicle body, which is particularly suitable for manufacturing a large-sized product having a complicated shape. Further, in the case of a die-cast product, since it is easy to design the thickness of the joining portion to be large, when the joining portion is joined to the side sill 2 or the roof 3 by a mechanical joining means such as a bolt, the joining portion has a large thickness. Since the load is not concentrated, it is advantageous in terms of strength as compared with those made of extruded members or sheet metal. Further, when the pillar cover 12 is fitted into the opening 11 of the pillar structural member 10 and the surfaces of these members are formed on the same surface, the FSW
When they are integrally joined by, for example, no large steps or dents occur on the joining surface, and the appearance is not impaired.

FIG. 5 is an exploded perspective view showing a third embodiment of the present invention, and FIG. 6 is a sectional view taken along line VI-VI of FIG. In this embodiment, a pillar structure member 25 is formed in a box body opened to the side of the vehicle body, and a flange 2
7 are integrally formed to protrude over the entire circumference, and a rib 28 is formed inside to form a zigzag shape and reinforced, and a positioning projection 30 is integrally formed on the surface of the flange 27 and the tip end surface 28a of the rib 28. are doing. Tip surface 2 of rib 28
8a forms the same surface as the surface of the flange 27.
In other words, the opening surface of the pillar structure member 25, the surface of the flange 27, and the tip surface 28a of the rib 28 form the same surface.

The pillar cover 31 is formed of a plate having substantially the same size as the flange 27,
0 has a plurality of positioning holes 32 to be fitted. The pillar cover 31 is positioned on the surface of the flange 27 by the positioning projection 30 and the positioning hole 32 so as to overlap with each other. 28
As in the above-described first and second embodiments, the distal end surface 28a is integrally joined by MIG welding, laser welding, FSW, or the like.

In such a structure, since the positioning projections 30 and the positioning holes 32 are provided, the pillar structure member 25 and the pillar cover 31 can be accurately positioned.

FIG. 7 is an exploded perspective view showing a fourth embodiment of the present invention, and FIG. 8 is a sectional view taken along line VIII-VIII of FIG. In this embodiment, a pillar structure member 35 is formed in a box body opened to the side of the vehicle body, and a flange 37 is integrally provided on an opening side edge of a surface 35a thereof over the entire periphery, and a rib 3
8 is formed so as to have a zigzag shape, and three positioning projections 40 are spaced apart in the longitudinal direction of the pillar structural member 35, and protrude integrally with the rib 38. The tip surface of the projection 40 forms the same plane as the surface of the flange 37. The flange 37 is formed in an L-shape, so that the surface 37 a is formed on the opening surface 3 of the pillar structural member 35.
5b, the inner side surface 37b forms the same surface as the surface 35a of the pillar structure member 35, and the inner side surface 37b and the opening surface 35b form a fitting recess 44 into which the pillar cover 41 fits. Has formed.

The pillar cover 41 is connected to the flange 3
7 has a plurality of positioning holes 42 into which the positioning projections 40 are fitted. The pillar cover 41 has an opening surface 35b of the pillar structure member 35 and an inner surface 37b of the pillar cover 37 by fitting the positioning protrusion 40 and the positioning hole 42.
The opening 36 of the pillar structure member 35 is closed by being positioned and fitted into the fitting concave portion 44 formed by the above. Then, the pillar structure member 35 and the pillar cover 41 are connected to the MI in the same manner as in the first, second, and third embodiments.
The center pillar 45 composed of a hollow closed-section structure is manufactured by integrally joining by G welding, laser welding, FSW or the like.

Also in such a structure, since the positioning projections 40 and the positioning holes 42 are provided, the pillar structure member 35 and the pillar cover 41 can be reliably positioned. If the depth of the fitting recess 44 is made equal to the thickness of the pillar cover 41 so that the surface 37a of the flange 37 and the surface of the pillar cover 41 are flush with each other, a step is generated when joining by friction stir welding or the like. The appearance is not impaired.

FIGS. 9 (a), 9 (b) and 9 (c) are exploded perspective views showing a fifth embodiment of the present invention, perspective views of main parts covered with pillar covers, and overlap joining. FIG. In this embodiment, a pillar structure member 25 is formed in a box opened to the side of the vehicle body, a flange 27 is integrally provided on an opening edge of the surface over the entire periphery, and a rib 28 is formed inside in a zigzag shape. And the pillar cover 31 is overlapped on the flange 27 and the rib 28, and the flange 27 and the pillar cover 31 and the rib 28 and the pillar cover 31 are
And overlap-joined.

In such a structure, there is no need to provide positioning projections or holes as compared with the embodiment shown in FIG. 5, and the pillar structure 25 and the pillar cover 31 can be easily manufactured.

FIG. 10 is an external perspective view of a center pillar showing a sixth embodiment of the present invention, FIG. 11 is a perspective view of a pillar structural member with a pillar cover removed, and FIG. 12 is a cross-sectional view taken along line AA of FIG. FIG. 13 is a sectional view taken along line BB of FIG. In this embodiment, a pillar structure member 45 and a pillar cover 46 are formed in a box having the same shape by die-casting, and are positioned by four positioning holes 47 and positioning pins (projections) 48. A center pillar 51 having a hollow closed cross-sectional structure is manufactured by mechanically joining with a bolt 49 and a nut 50.

The pillar structural member 45 is formed in a box opened to the side of the vehicle body, and has a rib 52 integrally formed therein so as to have a zigzag shape. The distal end surface 52a of the rib 52 forms the same plane as the opening surface 45a of the pillar structural member 45. Further, a bolt mounting portion 55 into which the bolt 49 is inserted is provided at two places of the rib 52. The bolt mounting portion 55 is formed of a large-diameter cylindrical portion 55a and a small-diameter cylindrical portion 55b by being formed in a cylindrical body of which both ends are open, and the inside of the large-diameter cylindrical portion 55a accommodates the nut 50. The nut housing portion 56 is formed, and the small-diameter cylindrical portion 5
The threaded portion of the bolt 49 passes through 5b.

The positioning holes 47 are circular non-through holes, and are provided at four inner corners of the pillar structural member 45, respectively.

The pillar cover 46 has the same external structure as that of the pillar structural member 45 except that the rib is not provided therein. However, the pillar structural member 45 having the rib 52 may be used as a pillar cover. Further, inside the pillar cover 46, two bolt mounting portions 60 are provided corresponding to the respective bolt mounting portions 55 of the pillar structural member 45. The bolt mounting portion 60 is formed in a cylindrical body having different diameters whose both ends are open, so that the large-diameter cylindrical portion 6 is formed.
0a and a small-diameter cylindrical portion 60b, and the inside of the large-diameter cylindrical portion 60a stores a head portion 49a of the bolt 49.
Is formed, and the screw portion of the bolt 49 penetrates through the small-diameter cylindrical portion 60b. In addition, circular non-through holes 62 are formed at the four inner corners of the pillar cover 46, respectively, and the positioning pins 48 are press-fitted into these holes 62, and the tip ends of the holes 62 are closer to the opening surface of the pillar cover 46. It protrudes and is fitted in the positioning hole 47.

In such a structure, the pillar structure member 45 and the pillar cover 46 are positioned and overlapped with each other by the positioning pin 48 and the positioning hole 47 being fitted, and the bolt 49 is attached to the bolt mounting portions 55 and 60.
And a nut 50 is fastened and integrally joined to form a center pillar 51 having a hollow closed-section structure.

In such a structure, since the fastening is performed by the bolt 49, the joining process by welding or FSW is not required, and the manufacturing process can be simplified.

FIG. 14 is an external perspective view of a center pillar showing a seventh embodiment of the present invention. In this embodiment, a pillar structure member 70 whose front surface (or back surface) and upper and lower ends are open, and a pillar cover 71 made of a flat plate are formed by die casting, and the front side opening of the pillar structure 70 is formed by the pillar cover 71. The center pillar 72 is formed of a hollow closed cross-sectional structure that is partially open by covering the center pillar 72. Other structures are substantially the same as those of the fifth embodiment shown in FIG. It will be apparent that the center pillar 72 having such a structure can provide the same effect as that of the fifth embodiment.

In each of the above-described embodiments, an example is shown in which the present invention is applied to a center pillar as a vehicle body structure. However, the present invention is not limited to this. The present invention can also be applied to a vehicle body structure such as the cross member 6, the rear cross member 7, and the suspension frame.

Further, although an example has been shown in which the pillar structural member is manufactured by die casting, it is not limited to this, and may be manufactured by another manufacturing method, for example, a VO die casting method. The VO die casting method is a casting method in which the interior of the cavity is evacuated, oxygen is injected in a predetermined amount, reduced, and then the molten metal is injected under pressure, which can significantly reduce defects inside the material. Therefore, it is possible to manufacture a lightweight structural member by reducing the thickness of each part of the structural member.

Further, in the sixth embodiment, the bolt 49 is used as the mechanical joining means. However, the present invention is not limited to this, and various changes and modifications such as using a rivet or an adhesive, or using them in combination. Is possible. Also,
In the above-described embodiment, the pillar structural member is formed in a box having one surface opened, but is formed in a box shape having two or more surfaces opened for convenience of die cutting, and the opening is covered with a cover. It may be a hollow closed cross-section structure.

[0043]

As described above, the automobile structure according to the present invention comprises a box-shaped structural member having at least one open surface and a cover which covers all or a part of the opening of the structural member. An automobile structure forming a hollow closed cross section, wherein the structural member is made of die-cast and integrally has a rib inside, and the cover is integrally joined to an opening of the structural member, so that the structural member is bent. A structure having high rigidity, torsional rigidity, bending strength, torsional strength and the like can be obtained. Also, since it is made of die cast, it has relatively high dimensional accuracy, and even if the shape of the car body is a curved surface, it can be formed in a shape that matches this, so that it matches the car body shape in a later process It is suitable for mass production of large and complicated shapes that do not need to be bent. In addition, since it is easy to form only the joining portion of the cast product with a thick wall, when joining to other members using a fastening means such as a bolt, a large load is not concentrated on the joining portion and the extruded shape or It is advantageous in terms of strength as compared with a sheet metal product.

Further, since the present invention is configured such that the structural member and the cover are positioned by the positioning projections and the positioning holes, the positioning can be performed reliably.

Further, when the structural member and the cover are integrally joined by friction stir welding, the joining can be performed more easily and quickly than ordinary welding, and the occurrence of distortion and oxide film can be prevented.

[Brief description of the drawings]

FIG. 1 is a perspective view of a monocoque body showing a first embodiment in which the present invention is applied to a center pillar of an automobile.

FIGS. 2A and 2B are an exploded perspective view and a sectional view of the center pillar.

FIG. 3 is an exploded perspective view showing a second embodiment of a center pillar.

FIG. 4 is a diagram for explaining bonding by FSW.

FIG. 5 is an exploded perspective view showing a third embodiment of the present invention.

FIG. 6 is a sectional view taken along line VI-VI of FIG. 5;

FIG. 7 is an exploded perspective view showing a fourth embodiment of the present invention.

8 is a sectional view taken along line VIII-VIII in FIG.

FIGS. 9A, 9B and 9C are an exploded perspective view showing a fifth embodiment of the present invention, a perspective view of a main part covered with a pillar cover, and a state in which overlap joining is performed. FIG.

FIG. 10 is an external perspective view of a center pillar showing a sixth embodiment of the present invention.

FIG. 11 is a perspective view of a pillar structural member with a pillar cover removed.

FIG. 12 is a sectional view taken along line AA of FIG.

FIG. 13 is a sectional view taken along line BB of FIG. 10;

FIG. 14 is an exploded perspective view showing a seventh embodiment of the present invention.

[Explanation of symbols]

4 center pillar, 10 pillar structure member, 11 opening, 12 pillar cover, 18 rib, 19, 20 flange, 25 pillar structure member, 26 flange, 30
... Positioning projection, 31 ... Pillar cover, 32 ... Positioning hole.

Continuing from the front page (72) Inventor Harumichi Hino 1-34-1 Kambara, Kambara-cho, Anbara-gun, Shizuoka Japan F-term in the Light Metal Corporation Group Technology Center (reference) 3D003 AA01 AA12 BB16 CA09 CA17 CA34 CA48 4E067 AA05 BG00 EA07 EB00

Claims (7)

[Claims] 1. An automobile structure in which a hollow closed cross-section is formed by a box-shaped structural member having at least one surface open and a cover covering the whole or a part of an opening of the structural member, A structural member for automobiles, wherein the structural member is made of die-cast and integrally has a rib therein, and the cover is integrally joined to an opening of the structural member. 2. The structure for an automobile according to claim 1, wherein the rib is formed so as to be located inside the opening of the structural member by an amount corresponding to the thickness of the cover, and the cover is supported by the rib. An automobile structure characterized by forming the same surface as an opening surface of the vehicle. 3. The automobile structure according to claim 1, wherein one of a structural member and a cover is provided with a positioning projection, and the other is provided with a positioning hole. An automobile structure, wherein the cover is positioned. 4. The structure for an automobile according to claim 1, wherein the surface of the structural member is integrally provided with a flange that forms the same surface as the cover at the edge on the opening side. Structure. 5. The structure for an automobile according to claim 1, wherein the structural member has a rib or web thickness just below the joint.
An automobile structure having a thickness of 0 mm or more, wherein the cover is integrally joined by friction stir welding. 6. An automobile structure according to claim 1, wherein the structural member and the cover are integrally joined by a mechanical joining means. . 7. The vehicle structure according to claim 1, wherein the structural member is manufactured by VO die casting.