JP2000142462A - Side frame structure of automobile - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve rigidity and strength of a joint portion between a center frame and a front frame which are jointed keeping an angle of a side frame of an automobile. SOLUTION: A front frame 6 is a frame with a rectangular cross section constituted by fitting a smaller inner frame 10 with a U-shaped cross section to a larger outer frame 11 with a U-shaped cross section, and a plurality of holes 5a are drilled through the upper and lower surfaces of a steel-pipe-made center frame 5 with a closed cross section. A reinforcement plate 12 with a U-shaped cross section is mounted in a joint place of the both, and the upper and lower surfaces of the reinforcement plate 12 are spot-welded with the outer frame 11 with the U-shaped cross section in the front frame 6, and are arc- welded through the holes 5a in the center frame 5. Rigidity and strength of a side frame 3 are improved to reduce deformation amount of a front portion of the side frame 3 caused by an impact from the front portion of a vehicle.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION Generally, a front wheel tire house is provided at a front portion of an automobile. Usually, a side frame is formed by connecting a pair of center frames to a pair of curved front frames in consideration of a step with the tire house. It is configured. The present invention relates to an automobile side frame structure having such a coupling structure.

[0002]

2. Description of the Related Art Hitherto, a ladder-shaped frame has been provided at a lower portion of an automobile for mounting an engine or supporting a body. Car 1 shown in FIG.
The frame 2 includes a pair of side frames 3 and a plurality of cross members 4. The side frame 3 is divided into several parts, and the front end of the center frame 5 at the center of the vehicle body is connected to the rear end of the front frame 6 whose rear part is curved and extends downward. In such a side frame structure, since the joint portion between the center frame 5 and the front frame 6 is bent, the joint portion is deformed when receiving an impact from the front, so that the impact can be absorbed. In addition, there is an advantage that the yield of the frame 2 is reduced by connecting the bent portion of the front frame 6 to the center frame 5 as a joint. Further, there has been proposed a structure in which a front side frame is strengthened by using a U-shaped cross-section frame and a plate-like plate to form a rectangular cross-section frame to improve the strength against collision (see JP-A-8-85472).

[0003]

In the case where the joint between the center frame 5 and the front frame 6 is bent by a large impact, if the amount of deformation is large, the room may be affected. Therefore, it is conceivable to form the side frame integrally without the joint, but in consideration of the yield of the frame, it is desirable to increase the thickness of the side frame itself or to provide a reinforcing member at the joint. However, if the side frame itself is made thick, the weight of the vehicle body becomes heavy, and if the reinforcing member is too large or the external mounting position is defective, it may hinder the installation of other members.

[0004] It is an object of the present invention to provide a side frame structure of an automobile in which strength and rigidity are appropriately increased.

[0005]

In order to achieve the above object, the present invention is directed to a first aspect of the present invention, in which two large and small frames each having a U-shaped cross section formed by press molding, and a frame having a large U-shaped cross section are formed outside the vehicle body. In a side frame structure of an automobile in which a first frame joined to a rectangular cross section and joined to a second frame formed into a closed cross section by extrusion molding at a fixed angle, A bent reinforcing plate having a U-shaped cross section is welded to a joint between the first frame and the second frame.

A second aspect of the present invention is characterized in that, in the first aspect of the present invention, the reinforcing plate is interposed and joined inside a joint portion between the first frame and the second frame.

According to a third aspect of the present invention, in the first aspect of the present invention, the reinforcing plate is joined to an outer side surface of a joint portion between the first frame and the second frame.

According to a fourth aspect of the present invention, in the second aspect, a welding hole is provided in the second frame, and a reinforcing plate interposed in the second frame is joined by arc welding. .

According to a fifth aspect of the present invention, in the third aspect of the present invention, a reinforcing plate having a U-shaped cross section is provided over the small vehicle body inner side surface of the first frame and the vehicle body inner side surface of the second frame. It is characterized by being joined.

The joint between the first frame and the second frame has a structure having a substantially rectangular angle, and the reinforcing plate is also bent substantially rectangular. The reinforcing plate can be formed in a U-shaped cross section by press molding.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below with reference to FIGS. 1 to 3A and 3B of the accompanying drawings. The front side frame 3 of the automobile shown in FIG. 1 is connected to a center frame (second frame) 5 on the center side of the vehicle body and a front frame (first frame) 6 whose rear portion is curved and directed downward. A strut bracket 7 is welded to the frame 6. Reference numeral 8 denotes a spring coil bracket, and reference numeral 9 denotes a mount bracket.

The center frame 5 is made of an extruded steel tube having a rectangular cross section (see FIG. 3B), and has a front portion connected to the front frame 6 with an opening. The front frame 6 is formed by welding two press-formed U-shaped inner frames 10 and a U-shaped outer frame 11 having a U-shaped cross section (see FIG. 3A). The larger U-shaped outer frame 11
The two joints are welded in a state of being sandwiched between the two edges of the rim, and have a rectangular cross section. Also, the front frame 6 has a rear portion curved downward, and the upper surface of the rear portion of the front frame 6 is inclined, but the lower surface is returned substantially horizontally at the end portion, the entire rear end is opened, and the center frame is The front end of 5 is guided for insertion.

Further, the reinforcing plate 12 shown by a dotted line in FIG.
As shown in FIG. 2, a plate having a U-shaped cross section is bent at an intermediate portion to form a substantially rectangular shape, and the reinforcing plate 12 forms a substantially rectangular shape of the center frame 5 and the front frame 6. It is designed to fit into the joint. Therefore, FIG.
As shown in (a), at the place where the inner wall of the U-shaped outer frame 11 and the outer surface of the reinforcing plate 12 are in contact, spot welding (arrow) is performed from the outer surface of the U-shaped outer frame 11,
The reinforcing plate 12 fitted into the center frame 5 is welded through a plurality of holes 5a formed in the center frame 5, as shown in FIG.

As described above, the structure of the side frame 3 is strengthened and the external dimensions are reduced by incorporating the reinforcing plate 12 at the bent joint between the center frame 5 formed by press forming and the front frame 6 made of steel pipe. It can be kept small. Further, by drilling a plurality of holes 5a on the upper and lower surfaces of the center frame 5, welding of the reinforcing plate 12 and the center frame 5 made of steel pipe from the holes 5a becomes possible, thereby increasing the reinforcing strength. In addition, since the reinforcing plate 12 is built in the side frame 3, the strut bracket 7 is provided.
And can be reinforced without disturbing the external mounting of the mounting bracket 9. In this embodiment, FIG.
As shown in FIG. 1, when an impact force (arrow) is applied to the side frame 3 from the front of the vehicle body, the side frame 3 conventionally tends to bend backward as shown by a two-dot chain line.
The reinforcing plate 12 is fitted in the front of the side frame 3 so that the front of the side frame 3 becomes strong.
Also, the amount of rearward movement of the cowl 14 is small, and the influence on the vehicle compartment can be reduced.

FIGS. 4 to 6 show another embodiment of the present invention.
This will be described with reference to (a) and (b). The center frame 5 and the front frame 6 of the side frame 3 shown in FIG.
As in the embodiment of FIG. 1, the rear end of the front frame 6 is curved downward, and the front end of the center frame 5 is inserted into the rear end of the curved portion. A reinforcing plate 12 (see FIG. 5) having a U-shaped cross section and an intermediate portion bent is attached to the inner side surface of the vehicle body of the center frame 5 and the front frame 6. That is, as shown in FIG. 6A, the front side of the front frame 6 and the reinforcing plate 12 are welded to the upper and lower surfaces of the U-shaped inner frame 10, and the center frame 5 and the reinforcing plate 12 are 6
As shown in (b), the inner surface of the reinforcing plate 12 is welded so as to sandwich the upper and lower surfaces of the center frame 5. In this embodiment, after assembling the side frame 3, the reinforcing plate 12 is welded to the joint of the bent side frame 3 on the inner side surface of the vehicle body. The reinforcing plate 12 having a U-shaped cross section is joined to the upper and lower surfaces of the U-shaped inner frame 10 of the front frame 6, and the upper and lower surfaces of the reinforcing plate 12 having the U-shaped cross section are upper and lower surfaces of the U-shaped outer frame 11 of the front frame 6. (See FIG. 6 (a)), so that when the other parts are mounted on the U-shaped outer frame 11, they are substantially flush with each other, so that the assemblability is improved.

[0016]

As described above, according to the first aspect of the present invention, the first frame and the second frame are joined at an angle to each other at a substantially elliptical shape along the joint. Since the reinforcing plate formed by bending both edges to form a U-shaped cross section is welded, strength and rigidity are increased, and bending against an impact force from the front can be reduced. According to the second aspect of the present invention, the reinforcing plate is two
Since it is built into one frame, the strength and rigidity are increased without affecting other parts. According to the third aspect of the present invention, since the reinforcing plate is welded to the inner side surface of the first frame and the second frame, the welding can be performed at any time during the frame assembling operation. Good workability. According to the fourth aspect of the invention, since the reinforcing plates are welded to both frames in the second aspect of the invention, the strength and rigidity are further increased, and the reinforcing effect is enhanced. According to the fifth aspect of the present invention, in the third aspect, the reinforcing plate is welded to the small U-shaped frame of the first frame, so that the step between the reinforcing plate and the large U-shaped frame is small. However, the effect on other parts to be attached to this location is small and the reinforcing effect is enhanced.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a joint portion between a center frame and a front frame of a side frame according to an embodiment of the present invention.

FIG. 2 is a perspective view of a reinforcing plate to be attached to a joint of FIG. 1;

3 (a) is AA in FIG. 1, and FIG. 3 (b) is FIG.
It is each sectional drawing of BB of FIG.

FIG. 4 is a perspective view showing a joint portion between a center frame and a front frame of a side frame according to another embodiment of the present invention.

FIG. 5 is a perspective view of a reinforcing plate to be attached to the joint of FIG. 4;

6 (a) is a view taken along the line CC of FIG. 4, and FIG.
It is each sectional drawing of DD.

FIG. 7 is a schematic diagram illustrating the operation of the embodiment according to the present invention.

FIG. 8 is a schematic view of a frame structure of a conventional automobile.

[Explanation of symbols]

 3 Side frame 5 Center frame 5a hole 6 Front frame 10 U-shaped inner frame 11 U-shaped outer frame 12 Reinforcement plate

Claims (5)

[Claims] 1. A two-frame press-formed frame having a U-shaped cross section, a first frame formed by arranging a large U-shaped frame on the outside of a vehicle body and joining them together in a rectangular cross-section, and forming a closed cross-section by extrusion. In a side frame structure of an automobile in which a second frame is joined at a certain angle of inclination, a reinforcing plate having a U-shaped cross section bent at the angle of inclination is provided between the first frame and the second frame. A side frame structure for an automobile, wherein the side frame structure is joined by welding to the joint of (1). 2. The side frame structure for an automobile according to claim 1, wherein a reinforcing plate is interposed and joined inside a joint between the first frame and the second frame. 3. The vehicle side frame structure according to claim 1, wherein the reinforcing plate is joined to an outer side surface of a joint between the first frame and the second frame. 4. The vehicle side frame structure according to claim 2, wherein a welding hole is provided in the second frame, and a reinforcing plate interposed in the second frame is joined by arc welding. 5. A reinforcing plate having a U-shaped cross section is joined to the inside surface of the vehicle body of the small frame of the first frame and the inside surface of the vehicle body of the second frame. Car side frame structure.