JPH08216639A - Structure of trailing arm type suspension - Google Patents

Abstract

PURPOSE: To reduce weight of a trailing arm type suspension and to facilitate its manufacture by improving strength of it by making it hard to cause stress concentration on a connecting point of a trailing arm and a torsion beam. CONSTITUTION: This is structure of a trailing arm type suspension in which an end part of a torsion beam 2 is inserted into an opening part 15 formed on an inside surface part 1A in the cawidth direction of a trailing arm 1 and welding to connect and fix this torsion beam 2 and the trailing arm 1 is applied along a marginal part of the opening part 15, and a hole part 14 is formed on an outside surface part 1B in the car width direction of the trailing arm 1. Consequently, the end part of the torsion beam 2 is extended to a forming point of the hole part 14 so as to pass through the inside of the trailing arm 1 along the car width direction and inserted into the hole part 14, and it is welded on the marginal part of this hole part 14.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a technique for increasing the connecting strength between a trailing arm and a torsion beam of a trailing arm type suspension of an automobile.

[0002]

2. Description of the Related Art As a trailing arm type suspension, there is a trailing arm type suspension in which a pair of left and right trailing arms that support a wheel and can swing in a vertical direction are connected to each other by a torsion beam extending in the vehicle width direction. With such a structure, the torsion beam can improve the rigidity in the vehicle width direction, and the torsion beam can also exhibit a so-called stabilizer function.

In such a suspension, the trailing arm and the torsion beam are usually connected by welding. Conventionally, for example, the structure shown in FIG. 6 has been adopted. That is, this conventional structure is
An opening 15 is formed in the inner side surface 1A of the trailing arm 1e in the vehicle width direction, a part of the end of the torsion beam 2e is inserted into the opening 15, and then welding is performed along the peripheral edge of the opening 15. It is a structure with W.

[0004]

In the above conventional structure,
As shown in FIG. 7, the cross-sectional structure of the connecting portion between the trailing arm 1e and the torsion beam 2e along the vehicle width direction changes abruptly in the portion where the welding W is applied.
That is, since the torsion beam 2e has a sectional structure in the range S1 inside the vehicle body relative to the position of the welding W, its rigidity is large, but in the range S2 outside the vehicle body, the torsion beam 2e and the trailing arm 1e are connected. Since it is not provided, the rigidity is substantially the same as the sectional structure in which only the trailing arm 1e exists. Therefore, the rigidity changes drastically at the position of the welding W as a boundary.

On the other hand, in this type of suspension, an input is generated from a bump stopper, a suspension spring, or the like at the time of full bumping of an automobile, so that the trailing arm 1e is centered on the support center line C of the trailing arm 1e. A very large twisting force may occur.

In the above-mentioned conventional structure, when the above-mentioned torsional force is generated, the position of the welding W where the sectional structure changes suddenly, particularly the position at the outermost position in the vehicle width direction among these welding positions ( Stress concentration was likely to occur in the portion indicated by reference character a in FIG. Therefore, conventionally, it has been necessary to take measures such as upgrading the material of each part, increasing the wall thickness, or adding a reinforcing plate in order to prevent the suspension from being broken or damaged due to the stress concentration. As a result, conventionally, there have been problems that the weight of the suspension is increased and the manufacturing cost is increased.

Incidentally, in the prior art, for example, the actual development of Sho 61-1
Although there is a suspension structure described in Japanese Patent No. 5616,
The structure disclosed in this publication basically has the same structure as that shown in FIGS. 6 and 7, and stress concentration easily occurs.

The present invention has been devised under such circumstances, and the strength is increased by making it difficult for stress concentration to occur at the connecting portion of the trailing arm and the torsion beam, and the trailing arm suspension is provided. It is an object of the present invention to reduce the weight and to facilitate the manufacturing.

[0009]

In order to solve the above problems, the present invention takes the following technical means.

That is, according to the present invention, the end of the torsion beam is inserted into the opening formed in the inner side surface of the trailing arm in the vehicle width direction, and welding for connecting and fixing the torsion beam and the trailing arm is performed. A structure of a trailing arm type suspension provided along a peripheral portion of the opening, wherein a hole is formed in an outer side surface portion of the trailing arm in a vehicle width direction, and an end of the torsion beam is formed. The portion is extended to the formation portion of the hole portion so as to penetrate in the trailing arm along the vehicle width direction and inserted into the hole portion,
Moreover, it is characterized in that it is welded to the peripheral portion of the hole.

The end of the stabilizer may be inserted into the hole separately from the trailing arm, and the end of the stabilizer may be fixedly attached to the peripheral edge of the hole. it can.

[0012]

According to the present invention, the end of the torsion beam is provided so as to penetrate along the vehicle width direction of the trailing arm, and the inner and outer side surfaces of the trailing arm in the vehicle width direction. Since at least two predetermined positions are welded to the end of the torsion beam, not only can the number of welding points be increased as compared with the conventional case, but also the entire area of the trailing arm in the vehicle width direction at the connecting portion between the trailing arm and the torsion beam. And the entire area of the end portion of the torsion beam inserted in the trailing arm can be effectively integrated. That is, in the present invention, the connecting portion between the trailing arm and the torsion beam does not have a portion where the cross-sectional structure of the torsion beam suddenly changes to a cross-sectional structure in which only the trailing arm exists, and the change in cross-sectional structure or rigidity is moderate. It becomes possible to

Therefore, according to the present invention, it is possible to appropriately prevent or suppress the occurrence of stress concentration at a specific portion of the connecting portion between the trailing arm and the torsion beam, and improve the suspension strength. As a result, it is possible to obtain an advantage that the thickness of each portion can be made smaller than in the past, and it is possible to obtain a special effect that the weight of the suspension as a whole and the manufacturing cost can be reduced.

In the hole of the trailing arm,
According to the structure in which the end portion of the stabilizer is inserted and fixed separately from the torsion beam, it is rational that the hole portion of the trailing arm can also be used for connecting and fixing the two members of the torsion beam and the stabilizer. You can save the trouble of adding a dedicated bracket part for mounting the stabilizer to the trailing arm separately.
Helps reduce manufacturing costs.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The preferred embodiments of the present invention will be described below.
A specific description will be given with reference to the drawings.

FIG. 1 is a plan view showing an example of a trailing arm type suspension to which the present invention is applied.
2 is a perspective view of a main part thereof, and FIG. 3 is an enlarged side view of arrow A in FIG.

In FIG. 1, this trailing arm type suspension includes a pair of left and right trailing arms 1 and 1.
1, a torsion beam 2 having both ends connected to the pair of trailing arms 1 and 1, and a stabilizer 3.
It is configured by including. In FIG. 1,
The arrow N1 direction is the front of the vehicle body, and the arrow N2 direction is the vehicle width direction.

As shown in FIG. 2, a bush 10 for attaching the trailing arm 1 to a vehicle body frame (not shown) is provided at the front end of each trailing arm 1. As a fulcrum, the entire trailing arm 1 can swing vertically. At the rear end of the trailing arm 1, a spindle shaft 11 for mounting wheels is provided in a protruding manner, and a mounting portion 12 for mounting a suspension spring and the like are appropriately provided.

In this embodiment, the trailing arm 1 has an upper member 1a and a lower member 1 which are divided into upper and lower halves.
It has a so-called monaca-like structure formed by joining with b. The upper member 1a and the lower member 1b are formed by pressing (deep drawing) a metal plate, and the lower peripheral edge portion of the upper member 1a and the upper peripheral edge portion of the lower member 1b are formed in the peripheral portion. Further, flanges (collars) 13a and 13b for joining the two to each other are appropriately provided.

However, in the outer side surface portion 1B of the trailing arm 1 in the vehicle width direction, a part of the upper side flange 13a located on the outer side surface portion 1B is curved upward and one of the lower side flange 13b is formed. By bending the portion downward, a hole portion 14 whose outer periphery is surrounded by the flanges 13a and 13b is formed. on the other hand,
An opening 15 for fitting the end of the torsion beam 2 is formed in an inner side surface 1A of the trailing arm 1 in the vehicle width direction, and the hole 14 is formed in the opening 1.
It is a through hole communicating with 5.

FIG. 4 is a sectional view taken along line X1-X1 of FIG. As shown in the figure, the torsion beam 2 is formed in a substantially U-shaped or V-shaped cross-section that is open at the front side of the vehicle body, and is formed by bending or bending a metal plate having a certain thickness, for example. . As shown in FIGS. 1 and 2, both ends of the torsion beam 2 extend from the opening 15 to the hole 14 of each trailing arm 1 so as to penetrate the inside of each trailing arm 1 along the vehicle width direction. It is inserted up to the formation point.

The torsion beam 2 is formed so that the portions of the pair of trailing arms 1 and 1 have substantially the same width, but the ends of the portions inserted into the trailing arms 1 are end portions. It is formed so that the width becomes narrower as it becomes closer to the portion, and it is considered that there is no hindrance to the insertion into the hole portion 14 formed to have a smaller size than the opening portion 15.

The welding W between each trailing arm 1 and the torsion beam 2 is performed not only on the peripheral edge of the opening 15 but also on the peripheral edge of the hole 14. Specifically, as shown in FIG. 3, the flange 1 with high strength is used.
The ends of the torsion beam 2 are brought into contact with 3a and 13b,
The welding W is applied to these contact points.

The stabilizer 3 is attached in order to enhance so-called roll rigidity and reduce rolling of the vehicle body. The torsion beam 2 has a stabilizer function, but the roll rigidity can be further increased by additionally providing the stabilizer 3.

As shown in FIG. 4, the stabilizer 3 is arranged in the torsion beam 2 and is provided along the longitudinal direction of the torsion beam 2. Then, as shown in FIGS. 1 and 2, both ends thereof are inserted into the holes 14 through the openings 15 of the trailing arms 1 as in the torsion beam 2. As shown in FIG. 3, the end of the stabilizer 3 is sandwiched between a pair of flanges 13a and 13b of the trailing arm 1 and fixed to these flanges 13a and 13b by tightening bolts and nuts 4 and 4a. Installed.

In the trailing arm type suspension having the above structure, the cross-sectional structure of the connecting portion between the trailing arm 1 and the torsion beam 2 is as shown in FIG. 5 (FIG. 5 shows the line X2-X2 in FIG. 1). It is a cross-sectional view). That is, the end of the torsion beam 2 penetrates the inside of the trailing arm 1, and welding W (W1, W2) is applied to each of the inner and outer both side surfaces 1A, 1B of the trailing arm 1. Therefore, even if a twisting force acts on the trailing arm 1 and the torsion beam 2 due to a vertical step between the left and right trailing arms 1 and 1 of this suspension, this force is concentrated at the position of the welding W1. Is avoided, and the position of the other welding W2 is also affected.

In the sectional structure shown in FIG. 5, the trailing arm 1 and the torsion beam 2 are efficiently integrated with each other, and the rigidity of each part of this connecting structure is little changed. . That is, in the connection structure shown in FIG. 5, the torsion beam 2 exists independently in the range Sa inside the position of the welding W1 and has a large rigidity. On the other hand, the range S outside the welding W1
In b, since the trailing arm 1 and the torsion beam 2 are connected not only by the welding W1 but also by the welding W2, the trailing arm 1 and the torsion beam 2 do not have a sectional structure in which the trailing arm 1 and the torsion beam 2 exist independently. The cross-sectional structure is a combination of 2 and 2.

Therefore, the range Sb is larger than the range Sa.
Although there is a tendency for the rigidity to increase, there is no sudden change in rigidity such as the rigidity of the torsion beam alone to the rigidity of the trailing arm alone. As a result, the stress caused by the torsional force is alleviated from being concentrated on a specific portion, and the strength of the entire suspension can be improved.

Further, when the above-mentioned twisting force is generated, this force also acts on the portion of the welding W2 of the hole portion 14, but this welding W2 has a large strength of the trailing arm 1. Since it is applied to the flanges 13a and 13b,
Sufficient durability strength will be obtained. Therefore, it is possible to eliminate the need to increase the overall thickness of the trailing arm 1.

Further, in the above trailing arm type suspension, the roll rigidity can be improved by providing the stabilizer 3, but the stabilizer 3 is attached to the hole portion 14 for fixing the torsion beam 2.
It is done using. Therefore, it is possible to save the trouble of separately forming a dedicated bracket portion for attaching the stabilizer 3 to the trailing arm 1. Also, FIG.
As shown in FIG.
In the structure in which the flanges 13a and 13b are clamped and bolted, the strength of the flanges 13a and 13b can be increased by being integrated with the stabilizer 3. Therefore, the strength of the peripheral portion of the hole portion 14 can be further increased, and the torsion beam 2 welded to the peripheral portion can be attached more reliably.

In the above embodiment, the holes 14 are formed by using the flanges 13a and 13b of the upper member 1a and the lower member 1b which form the trailing arm 1, and the strength of the peripheral portion of the holes 14 is increased. Although it is extremely excellent, the present invention does not necessarily have to be configured in this way. In the present invention, the hole 14 is formed in the flanges 13a, 1
The hole 3b may be an ordinary hole having a general structure, and the hole 14 may have any specific shape or size. Further, the trailing arm 1 may be manufactured by appropriately using, for example, a steel material having a U-shaped cross section without forming the trailing arm 1 with the upper member and the lower member.

In addition, in the present invention, the specific structure of each part such as the trailing arm and the torsion beam is not limited to the above-mentioned embodiment, and various design changes are possible.

[Brief description of drawings]

FIG. 1 is an overall plan view showing an example of a trailing arm type suspension to which the present invention is applied.

FIG. 2 is a perspective view of a main part of the trailing arm type suspension shown in FIG.

FIG. 3 is an enlarged side view of arrow A in FIG.

FIG. 4 is a sectional view taken along line X1-X1 of FIG.

5 is a sectional view taken along line X2-X2 of FIG.

FIG. 6 is a main part plan view showing an example of the structure of a conventional trailing arm suspension.

7 is a sectional view taken along line X3-X3 of FIG.

[Explanation of symbols]

 1 Trailing arm 1A Inner side (for trailing arm) 1B Outer side (for trailing arm) 2 Torsion beam 3 Stabilizer 14 Hole 15 Opening W Welding

Claims (2)

[Claims] 1. An end portion of a torsion beam is inserted into an opening formed in an inner side surface portion of a trailing arm in a vehicle width direction, and welding for connecting and fixing the torsion beam and the trailing arm is performed on the opening portion. A structure of a trailing arm type suspension provided along a peripheral edge portion, wherein a hole is formed in an outer side surface portion of the trailing arm in the vehicle width direction, and an end portion of the torsion beam is It is characterized in that the trailing arm is extended to a portion where the hole is formed so as to penetrate in the vehicle width direction, is inserted into the hole, and is welded to a peripheral portion of the hole. , Trailing arm suspension structure. 2. An end of a stabilizer is inserted into the hole separately from the trailing arm, and the end of the stabilizer is fixedly attached to the peripheral edge of the hole. The structure of the trailing arm suspension according to claim 1.