JPH11334646A - Vehicle body frame joint structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a joint structure that can improve strength in a side member joint portion by permitting spot welding. SOLUTION: In this joint structure, a side member 2 is composed of a front member 10 having a generally hat-shaped cross section with flanges 15b, 16b, and a rear member 11 with flanges 11a, 11c, in such a way that the front member 10 and the rear member 11 are jointed with lapping the flanges 15b and 11a, and 16b and 11c, respectively. Further, a first and a second reinforcements 20, 21 having generally hat-shaped cross sections with flanges 20a, 20c, 21a, 20c are formed at the joints of the front and rear members 10, 11. Spot weld portions S1 to S5 made of two or three layers are configured by providing notches 11b, 20b, 21b to one or two flanges out of the four layers. The four layers are configured by lapping the flanges 20a, 21a on the flanges 15b, 11a, or the flanges 20c, 21c on the flanges 16b, 11c.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a joint structure for a vehicle body frame, and more particularly, to a joint structure between a front member and a rear member constituting a side member of the body frame.

[0002]

2. Description of the Related Art For example, a vehicle body frame constituting a lower portion of an automobile generally has a structure in which a plurality of cross members are connected between left and right side members extending in the vehicle longitudinal direction. This side member may be divided into a front member and a rear member. In this case, the front end of the rear member is overlapped with the rear end of the front member, or a reinforcement is inserted between both members. It is common to intervene and combine (for example, JP-A-5-229452, JP-A-8-244).
No. 1).

By the way, a heavy object such as an engine unit is placed on the side member, and a large load is applied at the time of a collision. Therefore, it is necessary to increase the strength of the joint between the two members as much as possible. In this case, for example, the strength of the reinforcement is partially improved by a thickness difference press or the like in which the thickness of the specific component is increased, or two reinforcements are added and the two members are joined together. It is conceivable that it is joined to a part.

[0004]

However, increasing the strength of the reinforcement by the above-mentioned thickness difference press has a problem that the manufacturing cost increases.

[0005] In addition, when a two-piece reinforcement is added, the number of overlapping portions of the joining portion becomes excessively large because the number of joining portions between the front member and the rear member becomes four, and spot welding is impossible. It can be very difficult.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and provides a vehicle body frame connecting structure capable of improving the strength of a connecting portion of a side member by enabling spot welding while suppressing an increase in cost. It is intended to be.

[0007]

According to the present invention, a side member extending in the front-rear direction of a vehicle body comprises a front member having a substantially hat-like cross section and a rear member having a flange, and the flanges of the front member and the rear member are overlapped with each other. In the joint structure of the vehicle body frame joined together, the first and second reinforcements each having a substantially hat-shaped cross section are arranged at the joint between the front member and the rear member so that the four flanges are overlapped. And forming notches in one or two of the four stacked flanges to form two or three spots, and spot welding the spots. It is characterized by.

[0008]

According to the joint structure of the vehicle body frame of the present invention, the flanges of the first and second reinforcements are superimposed on the flanges of the front member and the rear member to form four sheets, one of which is provided. Alternatively, since two or three overlapping spots are formed by cutting out the two flanges, the spots can be spot-welded. As a result, the strength of the joint between the front member and the rear member can be improved, and there is an effect that the resistance to a load or the like at the time of a collision can be improved.

[0009] Further, since the strength is enhanced by arranging two reinforcements, the cost can be reduced as compared with the case where the strength is increased by a thickness difference press.

[0010]

Embodiments of the present invention will be described below with reference to the accompanying drawings. FIGS. 1 to 5 are views for explaining a connecting structure of a vehicle body frame according to an embodiment of the present invention. FIG. 1 is an exploded perspective view of a connecting portion of a side member constituting the vehicle body frame. Is a perspective view of a connecting portion of the side member, FIGS. 3 and 4 are cross-sectional views of the connecting portion of the side member, and FIG. 5 is a side view of the side member.

In FIG. 1, reference numeral 1 denotes a vehicle body frame disposed at a lower portion of a vehicle body, which is constituted by arranging left and right side members 2 and 2 extending in the vehicle longitudinal direction in parallel with each other. . A plurality of cross members (not shown) are provided between the left and right side members 2, and a vehicle body panel (not shown) is mounted above the side members 2.

An engine unit 3 is mounted at the center of the front end of the left and right side members 2. The engine unit 3 has a structure in which a clutch housing 5 and a transmission case 6 are connected to the rear end of an engine 4. The transmission case 6 is connected to the transmission case 7 for distributing the engine power to the front wheels and the rear wheels.

The side member 2 is mainly divided into a front member 10 and a rear member 11. The front member 10 includes a front half portion 10a extending substantially horizontally and linearly, and a rear half portion 10 extending obliquely downward from the rear end of the front half portion 10a and extending substantially horizontally linearly rearward from the lower end.
b.

The front half 10a has an inner panel 12 having a U-shaped cross-section and an outer panel 13 having a U-shaped cross-section.
Between the upper flanges 12a and 13a and the lower flange 12
b, 13b are joined together to form a closed section. The inner panel 12 has a plurality of beads 12c.
Are formed at intervals, and each bead 12c is for inducing an impact at the time of collision to compressive deformation in the axial direction. A reinforcement 14 is interposed between the inner panel 12 and the outer panel 13 (see FIG. 5).

The rear half 10b has a structure in which an inner panel 15 having a substantially L-shaped cross section and a lower flange 15a of a strip-shaped outer panel 16 are joined to each other, thereby opening upward. The cross section is almost hat-shaped. Front flanges 15b and 16b extending in the longitudinal direction are bent at the left and right opening edges of the rear half 10b.

The rear member 11 has a substantially hat-like cross section in substantially the same manner as the front member 10. Rear flanges 11 a and 11 c extending in the longitudinal direction are bent at left and right opening edges of the rear member 11. I have. A floor panel (not shown) is provided on the upper surface of the rear member 11 and a reinforce described later.

The front end of the rear member 11 is inserted so as to overlap the rear straight portion of the rear half 10b of the front member 10. The rear flanges 11a and 11c are superimposed on the front flanges 15b and 16b of the front member 10. Have been.

A first reinforcement 20 extending along the front member 10 is inserted therein.
A second reinforcement 21 extending along the rear member 11 is inserted therein. The first and second
The reinforcements 20 and 21 each have a substantially hat-shaped cross section that opens upward, and joining flanges 20a, 20c, and 21 extending in the longitudinal direction are provided on left and right opening edges.
a, 21c are formed.

The bottom wall 20d of the first rein hose 20 is located above the bottom wall of the front member 10, and
The right side wall is in contact with the inner surfaces of the left and right side walls of the front member 10 and forms a closed section with the front member 10. The bottom wall 21d of the second reinforcement 21 is located above the bottom wall of the rear member 11, and forms a closed cross section with the rear member 11 as described above.

The rear end of the first reinforcement 20 is superimposed on the front end of the rear member 11, and the front end of the second reinforcement 21 is superimposed on the rear end of the front member 10. Member 1
The connecting portion between the 0 and the rear member 11 is made up of four sheets.

The rear flanges 11a, 11c and the joining flanges 20a, 20a, except for the front flanges 15b, 16b of the front member 10 in the four-layer stack.
The notch portions 11 are respectively provided in some of the c, 21a and 21c.
b, 20b and 21b are formed. The notch portions 11b, 20b, and 21b form two or three overlapping first to fifth spot portions S1 to S5 at the joint portion, and the spot portions S1 to S5 are formed by spot welding. Are joined.

More specifically, the first spot portion S1 is formed by laminating the rear member 11 and the second reinforcement 21 in two pieces, and the second spot portion S2 is formed by a cutout portion of the second reinforcement 21. The rear member 11 is formed by 21b.
And the first reinforcement 20. Further, the third spot portion S3 is formed by overlapping the front member 10 and the second reinforcement 21 with the cutout portion 20b of the first reinforcement 20 and the cutout portion 11b of the rear member 11.

The fourth spot S4 is formed by the notch 20b of the first reinforcement 20 by the front member 1
0, rear member 11, and second reinforcement 21
Of three. The fifth spot portion S5 is formed by two sheets of the front member 10 and the first reinforcement 20.

Next, the operation and effect of this embodiment will be described. According to the present embodiment, the first and second rein hoses 20 and 2 are connected to the joint between the front member 10 and the rear member 11.
Since 1 is overlapped to form 4 sheets, the strength of the joint can be improved, and the resistance to the impact force at the time of collision can be improved. In addition, since four lower end bent portions of the side member 2 are stacked, the strength of the base of the front overhang portion can be increased, and the base can be prevented from being bent at the time of collision.

In this embodiment, notches 11b, 20b, 21b are formed in one or two of the four flanges 11a, 11c, 20a, 20c, 21a, 21c.
Is formed, thereby forming the spots S1 to S5 of two or three overlaps, so that spot welding can be performed while avoiding spot welding in four overlaps, which is difficult to perform on a production line. it can. In addition, since the two reinforcements 20 and 21 are provided to reinforce necessary parts, the cost can be reduced as compared with a case where the strength is partially increased by a thickness difference press or the like.

The notches 11b, 20b, 2
Since 1b is formed, spot welding of an excessive number of sheets can be avoided even when the floor panel is spot-welded on the side member 2.

In the above embodiment, each spot S
Although the case where three sheets of 1 to S5 are set to one place and the remaining two sheets are set to be stacked has been described, the present invention is not limited to this, and a plurality of three-sheet stacked spot parts may be formed. . In addition, all the spots may be formed by three sheets or two sheets.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view of a side member connecting portion for describing a connecting structure of a vehicle body frame according to an embodiment of the present invention.

FIG. 2 is a perspective view of a connecting portion of the side member.

FIG. 3 is a cross-sectional view of the side member (III- in FIG. 2).
III sectional view).

4 is a cross-sectional view of the side member (IV-I in FIG. 2).
V line sectional view).

FIG. 5 is a side view of the side member.

[Explanation of symbols]

 2 Side Member 10 Front Member 15b, 16b Flange 11 Rear Member 11a Flange 11b Notch 20 First Reinforcement 20a Flange 20b Notch 21 Second Reinforcement 21a Flange 21b Notch S1-S5 Spot

Claims (1)

[Claims] 1. A side member extending in a vehicle longitudinal direction,
A coupling structure of a vehicle body frame comprising a front member having a substantially hat-like shape having a flange and a rear member, and the flanges of the front member and the rear member are overlapped and joined to each other. 1, a second reinforcement is disposed at the joint between the front member and the rear member such that the four flanges are overlapped, and cut into one or two flanges among the four stacked flanges; A connecting structure for a vehicle body frame, wherein two or three overlapping spot portions are formed by forming notches, and the spot portions are spot-welded.