JPH11180123A - Trailing arm type suspension - Google Patents

Abstract

PROBLEM TO BE SOLVED: To eliminate considerable inferiority in mechanical strength of specific parts of suspension compared to other parts and increase the strength of the entire suspension without increasing the size of entire suspension, as well as enable the connecting work of the trailing arm and torsion beam to be done in an orderly fashion. SOLUTION: In the present suspension, a lengthwise end of a torsion beam 2 is inserted into an opening 14 formed on the inside of each trailing arm 1. The edge of the opening 14 of each trailing arm 1 is joined with the outside of the torsion beam 2 via a weld Wa. In this case, a flanged panel 19a or the like, which is shaped so that it stands up with the tip of the edge of the opening 14 bent towards the outside of the opening 14, is provided at the edge of the opening 14 of each trailing arm 1. Also, this flanged panel 19a of a stand up shape extends lateral to the vehicle from a location on the inside of the weld edge 90 of the outside of the weld Wa to a location farther to the outside than the weld edge 90.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a trailing arm type suspension used as a rear suspension of an automobile.

[0002]

2. Description of the Related Art The applicant of the present invention has disclosed a trailing arm type suspension of this type, for example, in Japanese Patent Laid-Open No. Hei 8-21.
No. 6639 has previously been proposed. As shown in FIGS. 8 and 9 of the present application, this conventional vehicle has a pair of left and right trailing arms 1e, 1e provided with a spindle shaft 11 for mounting wheels attached to longitudinal ends of a torsion beam 2e extending in the vehicle width direction. The parts are connected. Bushes 10, 10 for attachment to the vehicle body are welded to the front portions of the trailing arms 1e, 1e.
The whole can swing in the vehicle height direction. An opening 8 is formed in an inner side surface of each of the trailing arms 1e facing inward in the vehicle width direction. An end of the torsion beam 2e is inserted into the opening 8, and the opening 8 is formed. The periphery of the portion 8 and the outer surface of the torsion beam 2e are joined to each other via a weld W.

In such a trailing arm type suspension, if there is an input causing a vertical step in the two trailing arms 1e, 1e, the input is absorbed by bending deformation or torsion deformation of the torsion beam 2e. It is designed to ease. Also,
Since both ends of the torsion beam 2e are inserted through the openings 8 provided in each trailing arm 1e, the torsion beam 2e and the trailing arm 1e
The connection strength with e can be increased with a relatively simple structure.

[0004]

However, the above-mentioned conventional trailing arm type suspension has the following disadvantages.

That is, in the above-mentioned conventional trailing arm type suspension, when a pair of left and right trailing arms 1e, 1e has a step, which causes torsion deformation or bending deformation of the torsion beam 2e, each of the trailing arms 1e, Stress is generated at a welded portion W which is a joint portion with the torsion beam 2e. In this case, the weld W
Considering the stress generated in the torsion beam 2
The stress caused by the deformation of the welded portion e is a stress at the terminal end portion where the cross-sectional shape of the welded portion W is abruptly changed, more specifically, at the welded end 90e on the outer side in the vehicle width direction of the welded portion W. It is easier to concentrate. On the other hand, the cross-sectional shape of the periphery of the opening of the trailing arm 1e to which the above-mentioned welding is performed is merely a plate shape, and its mechanical strength is not so large. Therefore, conventionally, due to the concentration of stress at the welding end 90e, the mechanical strength of the portion is
It was relatively low compared to other parts, and the strength of the entire suspension was low. For this reason, conventionally, as a means for increasing the strength of the entire suspension, it has been necessary to form the entire trailing arm with a considerably large thickness or a large size, which is disadvantageous in terms of reducing the weight and size of the entire suspension.

In the conventional trailing arm type suspension, the opening 8 of the trailing arm 1e is provided.
In order to insert the ends of the torsion beam 2e therein and to appropriately connect them, it is necessary to strictly control the size of the opening width of the opening 8. However, conventionally, when manufacturing the trailing arm 1e by press molding, it has been difficult to finish the width of the opening 8 with high accuracy.

Further, in the prior art, the width of the opening 8 needs to be a dimension that does not cause a large play due to the torsion beam 2e. Therefore, the work of inserting the torsion beam 2e into the opening 8 is not so easy. Did not. Conventionally, when inserting the torsion beam 2 e into the opening 8, the end of the torsion beam 2 e comes into contact with the tip of the periphery of the opening 8,
There was also a risk that the surfaces of these members would be damaged. Therefore, conventionally, workability in assembling the torsion beam 2e to each trailing arm 1e is poor, and there is room for improvement in this respect.

The present invention has been conceived in view of such circumstances, and the mechanical strength of a specific portion of the suspension is reduced without causing a problem such as enlargement of the entire suspension as much as possible. It is an object of the present invention to eliminate the disadvantage that it is considerably inferior to that of the above-mentioned part, to increase the strength of the entire suspension, and to be able to appropriately perform the connection work between the trailing arm and the torsion beam.

[0009]

DISCLOSURE OF THE INVENTION In order to solve the above problems, the present invention employs the following technical means.

That is, the present invention comprises a pair of left and right trailing arms extending in the vehicle front-rear direction and swinging in the vehicle height direction, and a torsion beam extending in the vehicle width direction. The longitudinal end of the torsion beam is inserted into an opening formed on the inner side surface facing inward in the vehicle width direction, and the periphery of the opening of each of the trailing arms and the outer surface of the torsion beam are welded. A trailing arm type suspension, which is joined via a portion, wherein a trailing edge of an opening of each of the trailing arms has an upright bent outer end of the opening. A flange plate portion is provided, and the upright flange plate portion is welded from a vehicle width direction inner position of a welding end on a vehicle width direction outer side of the welding portion. It is characterized in that it extends to the vehicle width direction outer position than.

In the present invention, an upright flange plate having a leading edge bent at the periphery of the opening of each trailing arm is provided. The welded portion that joins the periphery of the opening to the outer surface of the torsion beam extends from the inside position in the vehicle width direction of the weld end on the vehicle width direction outer side to the position outside the weld end in the vehicle width direction. For this reason, the mechanical strength of the portion where the welded end of each of the trailing arms is located is enhanced by the upright flange plate portion, and the rigidity of the portion is subjected to such processing. It can be significantly increased as compared to the conventional one that does not. Therefore, according to the present invention, even when stress is concentrated on the welded end due to torsion or bending deformation of the torsion beam when the suspension is used, the torsion beam is sufficiently resistant to the stress. it can. On the other hand, since the upright flange plate portion is formed by bending the periphery of the opening of the trailing arm, the presence of the flange plate portion does not significantly increase the size of the entire trailing arm. As a result, according to the present invention, an effect is obtained in which the strength of the entire suspension can be effectively increased while appropriately avoiding an increase in the size and weight of the trailing arm.

Further, in the present invention, the shape preserving force of the periphery of the opening is increased by bending when forming the upstanding flange plate at the periphery of the opening of each trailing arm, and the width of the opening is increased. Dimensions can be managed properly,
The width of the opening can be accurately set to a desired dimension. Therefore, the dimensional control of the trailing arm is facilitated, and the manufacturing cost of the trailing arm can be reduced. Further, it is possible to reduce the possibility that the connection between the torsion beam and the trailing arm becomes difficult due to a dimensional error in the width of the opening, and to improve the assembling workability. In particular, in the present invention, when the end of the torsion beam is inserted into the opening, the upright flange plate portion bent outward of the opening can also serve as a guide for inserting the torsion beam. The work of inserting the torsion beam into the opening is further facilitated. As a result, the workability of assembling the trailing arm and the torsion beam can be further improved. Further, when the torsion beam is inserted into the opening, the torsion beam may come into contact with the surface of the upstanding flange plate portion, but the torsion beam is in contact with the peripheral edge of the opening portion having a relatively sharp cross section at the tip. As compared with the conventional case, there is also obtained an advantage that the surface of those members can be hardly damaged.

[0013]

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

FIG. 1 is a partially omitted plan view showing an example of a trailing arm type suspension according to the present invention. FIG. 2 is a perspective view of a main part of the trailing arm type suspension shown in FIG. FIG. 3 is a plan view of a main part of the trailing arm type suspension shown in FIG. FIG. 4 is an exploded perspective view of a main part of the trailing arm type suspension shown in FIG. FIG. 5 is a sectional view taken along line VV of FIG. FIG. 6 is a sectional view taken along line VI-VI of FIG. In these drawings, the arrow Fr indicates the front of the vehicle, the arrow w indicates the vehicle width direction, and the arrow Up indicates the vehicle width direction.

In FIG. 1, the trailing arm type suspension comprises a pair of right and left trailing arms 1 and 2.
1 and a torsion beam 2 connecting the pair of trailing arms 1 and 1.

Each of the trailing arms 1 and 1 extends in the front-rear direction of the vehicle and is opposed to each other at a predetermined interval in the vehicle width direction. A bush 10 for mounting the trailing arm 1 to a vehicle body frame (not shown) is provided at a front end of each of the trailing arms 1. Are swingable in the vehicle height direction (vertical direction). At the rear end of each trailing arm 1, a spindle shaft 11 for mounting wheels is protruded, and a mounting seat 12 for mounting a suspension spring and the like are appropriately provided.

As is clearly shown in FIG. 4, each of the trailing arms 1 has a so-called monaka-like hollow shape formed by joining an upper and lower divided upper member 1a and a lower member 1b. I have. The upper member 1a and the lower member 1b are formed by pressing (deep drawing) a metal plate, and the lower peripheral edge of the upper member 1a and the upper peripheral edge of the lower member 1b have both of them. Flanges 13a and 13b for joining to each other are appropriately formed.

A first opening 14 for inserting an end of the torsion beam 2 is provided in an inner side surface of each trailing arm 1 facing inward in the vehicle width direction.
The first opening 14 is formed between the upper member 1a and the lower member 1b of the trailing arm 1 by flanges 13a, 13b.
This is an opening formed by shaping the peripheral edge of both the upper member 1a and the lower member 1b without providing the same. This first opening 14 is
When the end of the torsion beam 2 is inserted into the opening 14, the trailing arm 1 extends from a substantially central portion in the longitudinal direction to the vicinity of the bush 10 so that a portion in front of the vehicle with respect to the torsion beam 2 is also opened. It is formed over a wide area.

The upper edge 17 of the periphery of the first opening 14
A and a lower edge portion 17b are provided with a series of barbed portions 18a and 18b, which are so-called barbed portions formed by press working. These nail processing parts 18
5 and 6, when the upper member 1a and the lower member 1b of the trailing arm 1 are formed by press working, the upper edge portion 17a and the lower edge portion 17b are formed. Of the upper edge 17 by a separate press working from the rest of the general part.
a and the lower edge 17b are displaced toward the inside of the opening 14 by an appropriate width. Such a nail processing part 18
By providing a and 18b, the dimensional accuracy of the opening width of the first opening 14 can be increased, and the rigidity of the periphery of the first opening 14 can be increased.

At the respective ends of the upper edge portion 17a and the lower edge portion 17b, standing flange plate portions 19a, 19b are provided.
Is provided. These flange plate portions 19a, 19
b is a portion formed by bending each end edge of the upper edge portion 17a and the lower edge portion 17b by press working, and stands up in the outward direction of the first opening portion 14. That is, the flange plate portion 19a of the upper edge portion 17a stands up, and the flange plate portion 19b of the lower edge portion 17b stands up. These flange plate portions 19a, 19
The formation range of b will be described later.

As is clearly shown in FIG. 2, the outer surface of each of the trailing arms 1 facing outward in the vehicle width direction includes:
A second opening 15 is provided. Unlike the first opening 14, the second opening 15 has a part of the flange 13a of the upper member 1a curved upward and a part of the lower flange 13b curved downward. This is a portion formed as an opening whose outer periphery is surrounded by both flanges 13a and 13b. If the second opening 15 has a shape surrounded by the flanges 13a and 13b, it is advantageous to increase the rigidity of the peripheral edge of the second opening 15.

As best seen in FIGS. 4 and 5,
The torsion beam 2 has a substantially V-shaped cross section or a substantially U-shaped cross section provided with an inclined upper piece 21a and a lower piece 21b forming an opening 20 on the front side of the vehicle. It is formed by bending or bending a plate. The torsion beam 2 extends in the vehicle width direction, and both ends in the longitudinal direction are inserted into positions near the rear of the first opening 14 of each trailing arm 1 as shown in FIGS. 1 and 2. Then, the tip of the trailing arm 1 is inserted into the second opening 15 as well.
Through in the vehicle width direction. The torsion beam 2
Is formed such that the width S2 of the portion inserted into the second opening 15 is smaller than the width S1 of the portion inserted into the first opening 14, and the second opening 15 is made as small as possible. Thus, care is taken to minimize the strength of the trailing arm 1 as much as possible.

As shown in FIG. 3, the first welding is performed by welding the upper end 17 a and the lower end 17 b of the peripheral edge of the first opening 14 to the outer surface of the torsion beam 2. The unit Wa is provided. The first welded portion Wa is not provided in the entire length region of the upper edge portion 17a and the lower edge portion 17b, and the upper edge portion 17a and the lower edge portion 17b are not provided.
Within the appropriate range. Therefore, the first
The welded end 90 of the welded portion Wa on the outer side in the vehicle width direction is located at an intermediate position between each of the upper edge portion 17a and the lower edge portion 17b. The peripheral portion A of the first opening portion 14 on the inner side in the vehicle width direction includes an upper member 1a and a lower member 1b.
Are joined together, so that the peripheral portion A is continuously welded. Therefore, the first welded portion Wa has a weld end 90 on the outer side in the vehicle width direction, but does not have a weld end on the inner side in the vehicle width direction.

On the other hand, the upright flange plate portions 19a,
19b is connected to the first welding portion Wa.
Are located more inward in the vehicle width direction than the welding end 90, and their ends N2 are located more outward in the vehicle width direction than the welding end 90, and the flange plate portions 19a, 19b
Are provided in a series from the start end N1 to the end N2. The start end N1 and the end N2 of the flange plate portions 19a and 19b are connected to these flange plate portions 1a and 19b.
In order to prevent the shapes of 9a and 19b from changing abruptly, they are formed in a shape whose rising dimension gradually changes.
The flange plate portions 19a and 19b and the first welded portion W
As shown in FIG. 5, welding is performed on the base end portions of the flange plate portions 19 a and 19 b at the portion where “a” overlaps.

In FIG. 2, the periphery of the second opening 15 and the outer surface of the torsion beam 2 are also welded, and a second welded portion Wb is provided. The torsion beam 2 and each trailing arm 1 are joined to each other via the first welding portion Wa and the second welding portion Wb.

Next, the operation of the trailing arm type suspension having the above configuration will be described.

When manufacturing the above suspension,
First, it is necessary to insert the end of the torsion beam 2 into the first opening 14 of each trailing arm 1. The opening size of the first opening 14 is determined by a barbed portion 18a formed by pressing. , 18b and upstanding flange plate portions 19a, 19b. On the other hand, such barbed portions 18a and 18b and the flange plate portion 19
For a and 19b, dimensional management by press working is relatively easy, and dimensional accuracy can be increased. Therefore, by increasing the dimensional accuracy of the first opening 14, the end of the torsion beam 2 can be inserted into the first opening 14 in an appropriate fitting state, and each trailing arm 1 can be inserted. Can be accurately connected to the torsion beam 2. Further, the upright flange plate portions 19a and 19b can also exert a guide-like action when the torsion beam 2 is inserted into the first opening 14. Therefore, the first
The operation of inserting the torsion beam 2 into the opening 14 can be more easily performed. On the other hand, when the first opening 14 is formed,
The processing accuracy of parts other than a and 18b and the flange plate parts 19a and 19b may be relatively rough. Therefore, the manufacture of the trailing arm 1 is also facilitated.

Next, in the above-mentioned suspension, when there is a load input that causes a step in the vertical direction to the pair of left and right trailing arms 1, 1, the torsion beam 2
A bending force or a torsional force acts on the joint between the torsion beam 2 and each trailing arm 1, that is, the first welded portion Wa and the second welded portion Wb. In this case, there is a tendency that a large stress acts on the first welded portion Wa closer to the longitudinal center portion of the torsion beam 2 than the second welded portion Wb. The stress tends to concentrate on the welded end 90 as a boundary point where the joint structure between the second and the trailing arms 1 suddenly changes. However, at the tips of the upper and lower edges 17a, 17b of the trailing arm 1, upstanding flange plates 19a, 19b are provided to increase the rigidity of these portions, and moreover, these flange plates 19a, 19a are provided. , 19b extend continuously from the inside in the vehicle width direction of the welding end 90 toward the outside in the vehicle width direction, so that the welding end 90 and its peripheral portion are appropriately reinforced. Therefore, it is possible to sufficiently cope with the stress acting on the welding end 90. As a result, the strength of the entire suspension can be increased without forming the entire trailing arm 1 with a thick member.

In the above embodiment, since the end of the torsion beam 2 is inserted through the first opening 14 and the second opening 15 of each trailing arm 1 in series, the trailing arm 2 is bent. Force or torsion force to the first opening 14
Of the second opening 15 as well as the peripheral edge of the second opening 15. Therefore, it is possible to reduce the stress generated in the first weld Wa, which is advantageous in increasing the suspension strength. However, the present invention is not limited to this, and the second
The opening 15 may not be provided. That is, in the present invention, a suspension structure having a structure in which an opening is formed only on the inner side surface of the trailing arm facing inward in the vehicle width direction, and a torsion beam is inserted into and joined only to this opening may be used.

Further, in the present invention, the opening formed in the inner side surface of the trailing arm is not necessarily the first opening.
It is not necessary to form the opening 14 at the front side of the insertion position of the torsion beam 2 like the opening 14 of FIG.
However, if the front side of the insertion position of the torsion beam 2 is opened as in the above-described embodiment, a relatively large torsional deformation can be generated in the trailing arm. The effect that the input load to the suspension can be absorbed also by the deformation of the ring arm is obtained.

Further, in the above-described embodiment, the upper and lower edges 17a, 17b of the periphery of the opening 14 are cut into the narrowed portions 18a, 18b.
The provision of 18b provides an advantage that the opening width of the first opening 14 can be more appropriately determined to a desired size, but the present invention is not limited to this. According to the present invention, for example, as shown in FIG. 7, the flanged portions 19a, 19b are provided at the tips of the upper and lower edges 17a, 17b without providing a cut edge on the periphery of the opening 14 of the trailing arm 1. May be provided.

Further, in the above embodiment, as shown in FIG. 3, the ends N of the upright flange plate portions 19a and 19b are formed.
2 is located in the middle of the periphery of the opening 14,
The present invention is not limited to this. For example, each of the flange plate portions 19a and 19b may be extended to a longer dimension so that the terminal end N2 is located near the bush 10. However, since the upright flange plate portions 19a and 19b are formed by bending the periphery of the opening, it is easier to manufacture the suspension by making the overall length shorter so that the suspension can be easily manufactured. Can increase productivity. The upright flange plate portion referred to in the invention of the present application is, in summary, from the vehicle width direction inner position of the weld end on the vehicle width direction outer side of the welded portion where the periphery of the opening of the trailing arm and the outer surface of the torsion beam are welded. What is necessary is just to extend to the position outside in the vehicle width direction from the welding end, and the specific length is not limited. The rising dimension (height) of the flange plate portion is not particularly limited. Furthermore, the flange plate does not necessarily need to stand at a substantially right angle with respect to the general surface of the trailing arm, and may stand at a slightly inclined angle.

In addition, the specific configuration of each part of the trailing arm type suspension according to the present invention is not limited to the above-described embodiment, and various design changes can be made.

[Brief description of the drawings]

FIG. 1 is a partially omitted plan view showing an example of a trailing arm type suspension according to the present invention.

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

FIG. 3 is a plan view of a main part of the trailing arm type suspension shown in FIG. 1;

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

FIG. 5 is a sectional view taken along line VV of FIG. 1;

FIG. 6 is a sectional view taken along line VI-VI of FIG. 1;

FIG. 7 is a sectional view of a main part showing another example of the present invention.

FIG. 8 is a plan view showing an example of a conventional trailing arm type suspension.

FIG. 9 is a sectional view taken along line IX-IX of FIG. 8;

[Explanation of symbols]

 Reference Signs List 1 trailing arm 2 torsion beam 14 first opening (opening) 15 second opening 17a upper edge 17b lower edge 19a, 19b flange plate 90 welding end Wa first welding (welding)

Claims (1)

[Claims] 1. A vehicle comprising: a pair of left and right trailing arms extending in a vehicle front-rear direction and swingable in a vehicle height direction; and a torsion beam extending in a vehicle width direction. The longitudinal end of the torsion beam is inserted into the opening formed on the inner surface facing the direction, and the periphery of the opening of each of the trailing arms and the outer surface of the torsion beam are welded through a weld. A trailing arm type suspension that is joined, wherein a peripheral flange of an opening of each of the trailing arms has an upright flange plate having a leading edge of the periphery bent outwardly of the opening. The upright flange plate portion is provided between the inside of the welding end on the outer side in the vehicle width direction of the welding portion and the outer side in the vehicle width direction from the welding end thereof. Characterized in that it extends to location, trailing arm.