JP2000128019A - Method of manufacturing tapered body skeleton structure for vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To optimally set buckling strength without increasing weight by forming a tapered portion by effectively using all of an extruded material having a closed cross section. An extruded material having a rectangular closed cross section is provided.
Is cut along cutting lines 14 and 16 inclined with respect to the longitudinal axis 12 so that its closed cross section is an open cross section, forming two cut pieces 18 and 20. After performing necessary processing on the cut pieces 18 and 20, one cut piece 20 is inverted in the longitudinal direction with respect to the other cut piece 18 so that deep portions and shallow portions of the open section face each other. Cutting portions 14a and 16b of two cutting pieces 18 and 20 and cutting portion 14
b and 16a are joined by butt welding to form a body skeleton structure 24 having a tapered shape over the entire length.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a body skeleton structure of a vehicle such as an automobile, and more particularly to a method of manufacturing a tapered body skeleton structure.

[0002]

2. Description of the Related Art As one method of manufacturing a body skeleton structure of a vehicle such as an automobile, for example, as described in JP-A-9-202263, two flat portions having a closed cross section and facing each other are used. An extruded material having a step portion corresponding to each plate thickness is prepared, and the step portion is cut by a predetermined length, and a slit in a direction perpendicular to the cut portion is formed at an inner end position of the cut portion. Conventionally, there has been known a method of manufacturing a body skeleton structure in which a compressive force is applied along the two plane portions to form a tapered shape, and a cut portion and a slit portion are welded.

According to such a method of manufacturing a body skeleton structure, a portion having a predetermined length is formed in a tapered shape by using a relatively inexpensive extruded material without requiring high-cost processing means such as press working. The resulting body skeleton structure can be manufactured.

[0004]

However, in the above-mentioned conventional method for manufacturing a body skeleton structure, the two flat portions of the tapered portion overlap each other at a relatively large overlap margin. For this reason, there is a problem that the weight becomes larger than the size of the body skeleton structure, and there is a problem that the buckling strength of the tapered portion cannot be set optimally.

In order to solve these problems, a region having a predetermined length including a step portion must be cut into a V-shape, which causes a problem that a cutting process becomes complicated and a yield is deteriorated. .

Further, in the above-mentioned conventional method for manufacturing a body skeleton structure, a step portion remains in a region other than a tapered portion, so that the appearance (design) of the body skeleton structure is poor. In addition, there is a problem that occurrence of a step due to the overlap between the two flat portions in the tapered portion is inevitable.

The present invention relates to a conventional method for manufacturing a tapered body skeleton structure, and more particularly to a tapered body formed by using an extruded material having a closed cross section and a stepped portion corresponding to each plate thickness at two flat portions facing each other. The present invention has been made in view of the above-described problems in the above-described method of manufacturing the body skeleton structure that forms the shape-forming portion, and a main object of the present invention is to provide an extruded material having a closed cross-section. By effectively utilizing the tapered portion, the buckling strength is optimally set without causing a problem such as an increase in weight.

[0008]

SUMMARY OF THE INVENTION According to the present invention, there is provided, according to the present invention, an extruded material having a closed cross-section in a longitudinal direction such that the closed cross-section becomes an open cross-section. Cutting at an angle, inverting one of the cut pieces in the longitudinal direction with respect to the other cut piece, and joining the cut portions of the two cut pieces by a method of manufacturing a tapered body skeleton structure for a vehicle. Achieved.

According to the first aspect of the present invention, an extruded material having a closed cross section is cut at an angle to the longitudinal direction so that the closed cross section becomes an open cross section, and one cut piece is cut into the other cut piece. On the other hand, since the cut portions of the two cut pieces are joined in the longitudinal direction, the tapered body skeleton structure is formed by effectively using all of the extruded material.

According to the present invention, in order to effectively achieve the above-mentioned main object, in the above-mentioned structure of the first aspect, the cut portions of the two cut pieces are butt-welded. Configuration of item 2).

According to the second aspect of the present invention, since the cut portions of the two cut pieces are butt-welded, no step is generated at the joint portion between the two cut pieces, and the body skeleton has no step at any part. A structure is formed.

[0012]

According to a preferred aspect of the present invention, in the configuration of the first aspect, the closed section is configured to be rectangular (preferred aspect 1).

According to another preferred embodiment of the present invention, in the configuration of the preferred embodiment 1, the extruded material is cut along a cutting surface inclined with respect to two mutually opposing flat portions. (Preferred embodiment 2).

According to another preferred embodiment of the present invention, in the configuration of the preferred embodiment 2, the extruded material is cut so that the open sections of the two cut pieces are the same from one end to the other end. (Preferred embodiment 3).

According to another preferred embodiment of the present invention, in the configuration of claim 1, at least one of the cut pieces is processed before joining the cut portions of the two cut pieces. (Preferred embodiment 4).

According to another preferred embodiment of the present invention, in the configuration of the first aspect, the cut portions of the two cut pieces are partially overlapped and joined by fillet welding. (Preferred embodiment 5).

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below in detail with reference to the accompanying drawings.

FIGS. 1 to 4 are explanatory views showing a series of steps of a method of manufacturing a tapered body skeleton structure according to the present invention. In particular, FIG. 1 is a perspective view showing an extruded material having a rectangular closed cross section. FIG. 2 is a perspective view showing an extruded material cut inclining with respect to a longitudinal direction so that a closed cross section becomes an open cross section, and FIG. 3 shows one cut piece in the longitudinal direction with respect to the other cut piece. FIG. 4 is a perspective view showing an inverted state, and FIG. 4 is a perspective view showing a tapered body skeleton structure formed by butt welding cut portions of two cut pieces.

In these figures, reference numeral 10 indicates an extruded material having a rectangular closed cross section, and the extruded material 10 extends along a longitudinal axis 12 with a constant cross-sectional shape. . In particular, in the illustrated embodiment, the extruded material 10 has a pair of long sides 10a and 10b facing parallel to each other, and a pair of short sides 10c extending perpendicular to them and facing parallel to each other. 10d, and FIG.
As shown in FIG. 2, portions of the long sides 10a and 10b protrude in the opposite directions by the same amount from the portion of the rectangular closed cross section.

As shown in FIG. 2, the extruded material 1
0 is cut along the cutting lines 14 and 16 at the pair of long sides 10a and 10b, for example, by laser cutting, thereby forming two cut pieces 18 and 20 having the same shape and size as each other. . Cutting line 14 in this case
The cutting plane 22 defined by the steps 16 and 16 is a long side 10a.
And 10b are inclined with respect to the plane and intersect the longitudinal axis 12 at the longitudinal center of the extruded material 10 so that the cross-sectional shape of the upper and lower ends of the cut piece 18 in the drawing of the cut piece 18 respectively In the drawing, the sectional shapes of the lower and upper ends are the same, and the open cross sections of the two cut pieces are the same from one end to the other end.

Next, as shown in FIG.
The part 10a 'of the long side 10a and the part 10b "of the long side 10b are aligned with each other along one plane, and the part 10a'
The cutting piece 20 is longitudinally inverted with respect to the cutting piece 18 so that the b 'and the part 10a "of the long side portion 10b are aligned with each other along one plane, so that the two cutting pieces 18 and 2
0 is a state where deep portions and shallow portions of the open sections face each other.

Further, as shown in FIG. 4, the cut pieces 18 and 20 are positioned so that the cut parts 14a and 16b of the two cut pieces 18 and 20 abut each other and the cut parts 14b and 16a abut each other. In this state, the cut portions 14a and 16b and the cut portions 14b and 16a are butt-welded to each other by, for example, laser welding, whereby the body skeleton structure 24 having a tapered shape from one end to the other end is formed.

Thus, according to the illustrated embodiment, the extruded material 10 having a rectangular closed cross section has a cutting line 14 inclined with respect to the longitudinal axis 12 such that the closed cross section is an open cross section.
And 16, one of the cut pieces 20 is longitudinally inverted with respect to the other cut piece 18, and the two cut pieces 1 are cut.
Since the cut portions 8 and 20 are joined to each other, it is possible to easily and efficiently form the body skeleton structure 24 having a tapered shape over the entire length by effectively using all of the extruded material 10. it can.

In particular, according to the illustrated embodiment, the extruded material 10 has no steps and has two cut pieces 18.
And 20 cutting sections 14a, 16b and cutting sections 14b, 1
6a are butt-welded to each other, so that a tapered body skeleton structure 24 having an excellent design can be formed without any step, and the cut portions of the two cut pieces 18 and 20 are overlapped with each other. The ratio of weight to size can be reduced as compared with the case where welding is performed.

According to the illustrated embodiment, the extruded material 10 having a closed cross section is cut along cutting lines 14 and 16 inclined with respect to the longitudinal axis 12 so that the closed cross section becomes an open cross section. Of the other piece 18
And the two cut pieces 18 and 20
Are joined together, so that the cut pieces 18 and 20
18 or 2 before they are integrally joined together
Necessary processing can be easily and efficiently performed on 0.

For example, when the body skeleton structure 24 formed as described above is used as a center pillar of an automobile, the body skeleton structure 24 can be subjected to necessary processing for the center pillar, and the front seat can be formed. The anchor reinforce of the seat belt can be easily and firmly attached.

FIG. 9 is a cross-sectional view showing how to attach the anchor reinforcement 26 prior to the welding step shown in FIG. As shown in FIG. 9 (A), first, a substantially semicircular shape for attaching the anchor reinforcement 26 to the cut portion of the portion 10a 'of the long side of the cut piece 18 and the portion 10b "of the cut piece 20 is shown. Notches 28a and 28b
Is formed, for example, by cutting.

Next, as shown in FIG. 9B, a nut 30 is provided on the inner surface of the dish 26a having a circular dish 26a and a rectangular flange 26b around the dish 26a in plan view.
An anchor reinforce 26 is prepared by fixing the anchor reinforce 26 so that the flange portion 26b abuts on the inner surface of the long side portion 10a 'and the dish-shaped portion 26a projects outward from the notch 28a. Is positioned with respect to the notch 28a, and a portion 1 of the long side portion is
0a '.

Further, as shown in FIG. 9 (C), the cut pieces 18 and 20 of the two cut pieces 18 and 20 are brought into contact with each other and the cut parts 14b and 16a are brought into contact with each other. 20 is positioned, and in this state, the cut portions 14a and 16b and the cut portions 14b and 16a are butt-welded to each other, whereby the body skeleton structure 24 is formed.
Is formed, and the flange portion 26b is fixed to a part 10b ″ of the long side portion 10b by, for example, performing fillet welding at the welded portion 26d.

FIG. 10 is a cross-sectional view showing a structure for attaching the anchor reinforcement 26 to a conventional body skeleton structure 32 having a closed cross section like the extruded material 10. In the case of the conventional structure shown in FIG.
It is not easy to form the hole 34 for receiving the nut 30 of the anchor reinforce 26 at 0e, and the flange 26b of the anchor reinforce 26 cannot be arranged inside the closed cross section of the body skeleton structure 32. 26b must be welded to the outer surface of the long side 10e, and efficient spot welding cannot be adopted as a welding method.

Generally, as shown in FIGS. 9C and 10, a force F is applied to the anchor reinforcement 26 to separate the anchor reinforcement from the body skeleton structure 24 and the extruded material 32. Therefore, in the case of the conventional structure in which the flange portion 26b must be welded to the outer surface of the long side portion 10e, a strong force for peeling the welded portion is generated in the welded portion 36 due to the force F. The weld 36 must be formed so strongly that it acts and does not yield to this great force.

On the other hand, according to the illustrated embodiment, the flange portion 26b is located inside the body skeleton structure 24, and most of the force caused by the force F is directly transmitted from the flange portion 26b to the long side portion 10b. Since it is transmitted mechanically, a strong force does not act on the spot weld and the fillet weld, and the durability of the attachment portion of the anchor reinforce 26 can be greatly improved.

FIG. 11 is a cross-sectional view showing a press working that may be performed on the cut piece 18 prior to the welding step shown in FIG. 4, and FIG. 11A particularly shows the formation of a bead.
(B) shows the formation of a burring hole.

In FIG. 11A, a pressing force Fp for moving the cutting piece 18 inward is applied to the corner of the cutting piece 18 so that a desired position of the cutting piece 18 in a desired longitudinal direction is provided. A bead 38 extending over the area is formed. In the illustrated embodiment, the bead 38 has a chamfered shape, but the bead may have any shape.

In FIG. 11 (B), a piercing force Fh is applied to the short side 10c of the cut piece 18, whereby a burring hole 42 having a lip portion 40 protruding outward on the short side 10c. It is formed. The burring hole may be formed so that the lip portion protrudes inward.

As can be seen from FIGS. 11A and 11B, according to the illustrated embodiment, it is easy to perform necessary processing on the cut pieces 18 or 20 before the cut pieces 18 and 20 are integrally joined. In addition to being able to perform efficiently, the buckling deformation mode when the body skeleton structure 24 receives a compressive load in the longitudinal direction by the beads 38 and the like can be controlled, and the attachment and insertion of other parts can be controlled. Means, such as a burring hole 42, for performing this can be formed at a desired position in a desired form.

Although the present invention has been described in detail with reference to specific embodiments, the present invention is not limited to the above-described embodiments, and various other embodiments may be included within the scope of the present invention. It will be clear to those skilled in the art that is possible.

For example, in the above-described embodiment, the closed cross-sectional shape of the extruded material is rectangular, but the closed cross-sectional shape of the extruded material may be a polygon not less than a quadrangle, such as a circle or an ellipse. It may have a closed cross-sectional shape of a curve. When the closed cross-sectional shape is a polygon having a quadrangle or more, the polygon preferably has two sides parallel to each other, and the extruded material is preferably cut at the two sides.

In the above embodiment, the cut pieces 18 and 20 are positioned so that the cut parts 14a and 16b of the two cut pieces 18 and 20 abut each other and the cut parts 14b and 16a abut each other. In this state, the cut portions 14a and 16b and the cut portions 14b and 16a are butt-welded to each other. For example, as shown in FIG. 12, the cut portions 14a and 16b are overlapped with each other. The cut pieces 18 and 20 are positioned so that the cut portions 14b and 16a are overlapped with each other, and in this state, the cut portions 14a and 16b and the cut portions 14b and 16a fill with each other at the welded portion 44. It may be welded. In this case, the joining of the cut portions of the two cut pieces 18 and 20 can be performed more easily than in the case of the above-described embodiment.

Further, in the above-described embodiment, the extruded material 10 has the cutting plane 22 inclined in a direction parallel to the plane of the long sides 10a and 10b and the extruded material 10 at the center in the longitudinal direction of the extruded material 10. The cutting plane 22 is cut into two pieces 18 and 20 by being set so as to intersect the longitudinal axis 12.
It may be cut into two cutting pieces 18 and 20 in a state set to intersect the longitudinal axis 12 at one end or the other end with respect to the center in the longitudinal direction of 0.

[0041]

As is apparent from the above description, according to the method of the first aspect of the present invention, the extruded material having a closed cross section is inclined with respect to the longitudinal direction so that the closed cross section becomes an open cross section. It is cut, one cut piece is inverted in the longitudinal direction with respect to the other cut piece, and the cut portions of the two cut pieces are joined, so that all of the extruded material is effectively used, and a tapered body skeleton structure is used. The body can be easily and efficiently manufactured.

According to the method of the first aspect of the present invention, the overlap of the cut portions of the two cut pieces can be set to 0 or a minimum value. As compared with the case, the weight ratio to the size of the body skeleton structure can be reduced, and the buckling strength of the body skeleton structure can be optimized.

According to the method of claim 1 of the present invention, even if the extruded material itself is the same, one end of the two cut pieces can be obtained by changing the inclination angle of the cutting line with respect to the longitudinal direction of the extruded material. The degree of change in the depth of the open section to the other end can be arbitrarily changed, whereby the degree of taper of the body skeleton structure can be easily and arbitrarily changed.

According to the second aspect of the present invention, since the cut portions of the two cut pieces are butt-welded, no step is generated at the joint portion of the two cut pieces, and the body having no step at any portion is formed. A skeletal structure can be formed.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an extruded material having a rectangular closed cross section.

FIG. 2 is a perspective view showing an extruded material cut inclining with respect to a longitudinal direction so that a closed cross section becomes an open cross section.

FIG. 3 is a perspective view showing a state in which one cut piece is inverted with respect to the other cut piece in the longitudinal direction.

FIG. 4 is a perspective view showing a tapered body skeleton structure formed by butt-welding cut portions of two cut pieces.

FIG. 5 is a cross-sectional view of the extruded material shown in FIG.

6A is a cross-sectional view of the upper end of the two cut pieces shown in FIG. 2 and FIG.

7A is a cross-sectional view of the upper end of the two cut pieces shown in FIG. 3 and FIG.

FIG. 8 is a cross-sectional view of the upper end (A) and a cross-sectional view of the lower end of the tapered body skeleton structure shown in FIG. 4;
It is.

FIG. 9 is a cross-sectional view showing a procedure for attaching an anchor reinforce prior to a welding step.

FIG. 10 is a cross-sectional view showing a structure for attaching an anchor reinforcement to a conventional body skeleton structure.

FIG. 11 is a cross-sectional view showing a press working that may be performed on a cut piece prior to the welding step shown in FIG. 4;
In particular, (A) shows the formation of beads and (B) shows the formation of burring holes.

FIG. 12 is a cross-sectional view showing two cut pieces subjected to fillet welding.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 ... Extruded material 14, 16 ... Cutting line 18, 20 ... Cut piece 20 ... Cutting plane 24 ... Skeletal structure 26 ... Anchor reinforcement

Claims (2)

[Claims] An extruded material having a closed cross section is cut obliquely with respect to a longitudinal direction so that the closed cross section becomes an open cross section, and one cut piece is turned in the longitudinal direction with respect to the other cut piece,
A method for producing a tapered body skeleton structure for a vehicle, comprising joining cut portions of two cut pieces. 2. The method according to claim 1, wherein the cut portions of the two cut pieces are butt-welded.