JP3196007B2 - Trailing arm suspension structure - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

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

[0002]

2. Description of the Related Art As a means for increasing the connection strength between a trailing arm of a trailing arm type suspension and a torsion beam, Japanese Patent Application No. 7-2400 is proposed.
The means described in No. 0 was first conceived. This means, as shown in FIG. 6 of the present application, is provided with a first opening 14e and a second opening 15e on both inner and outer side surfaces 1C and 1D in the vehicle width direction of a trailing arm 1e extending in the vehicle front-rear direction. These two openings 14e and 15e are means for inserting an end of a torsion beam 2e having a substantially V-shaped cross section or a substantially U-shaped cross section which is open at the front side of the vehicle. Further, welding Wa, Wb for fixing the torsion beam 2e is applied to each peripheral edge of the two openings 14e, 15e.

According to such means, the trailing arm 1e and the torsion beam 2e can be connected to each other on both the inner and outer side surfaces 1C and 1D of the trailing arm 1e. Therefore, in the above means, one opening (the first opening 14e) provided in the trailing arm is provided.
Compared to the conventional suspension structure in which the end of the torsion beam is inserted and welded only at the portion corresponding to the above, the advantage that stress concentration is less likely to occur at the welded portion and the strength of the suspension can be increased. .

[0004]

However, the structure of the suspension has the following disadvantages.

That is, in the above-described suspension structure, when the torsion beam 2e is inserted near the rear end of the inner peripheral edge of the first opening 14e and the second opening 15e and connected to the inner peripheral edge of the second opening 15e. A relatively large gap S2 between the end portion 81 and the rear portion 29b of the torsion beam 2e is allowed to some extent. In contrast, the first opening 14e of the trailing arm 1e
In the opening position of the first opening 14e, it is necessary to bring both parts as close as possible so that a large gap S1 does not occur between the rear end portion 80 of the inner peripheral edge of the first opening portion 14e and the rear portion 29a of the torsion beam 2e. is there. This is because the load on the torsion beam 2e when a force such as torsion or bending acts on the first opening 1 is larger than that of the second opening 15e.
This is because, since the position of 4e is larger, it is necessary to increase the degree of contact between the periphery of the first opening 14e and the torsion beam 2e so as to ensure that the welding at this position is firm.

On the other hand, when manufacturing the trailing arm 1e, the first and second openings 14e, 15e
In some cases, some processing dimensional errors may occur in the formation position of the pits. For this reason, in the actual manufacture of the trailing arm 1e, even if a slight dimensional error occurs at the positions of the two openings 14e and 15e, the torsion beam 2e is inserted into the two openings 14e and 15e. In order not to form a large gap S1 between the torsion beam 2e and the rear end 80 of the inner peripheral edge of the first opening 14e, the second opening 15e may be formed to be larger. Alternatively, the second opening 15e is connected to the first opening 14
It is necessary to pay attention to the formation nearer to the rear of the vehicle than e. Therefore, in the above suspension structure, the gap S2 between the rear end portion 81 of the inner peripheral edge of the second opening 15e and the rear portion 29b of the torsion beam 2e tends to increase.

However, in the above suspension structure,
Although the existence of the gap S2 is permissible, when the gap S2 becomes large, as shown in FIG. 7, the outer surfaces of the upper piece 21e and the lower piece 21f of the torsion beam 2e and the second opening 15e are accordingly formed. Also increases in the mutual dimension δ with the peripheral portion of the substrate. As a result, with the above suspension structure, it was difficult to weld the periphery of the second opening 15e to the torsion beam 2e.

In the structure of the suspension, the torsion beam 2e having a substantially V-shaped cross section or a substantially U-shaped cross section is provided.
, That is, the mutual angle θ between the inclined upper piece 21e and lower piece 21f of the torsion beam 2e is the same in various places. For this reason, if the central portion in the longitudinal direction of the torsion beam 2e is made large,
It is necessary to increase the opening area of the second opening 15e for inserting the end of e. Therefore,
The disadvantage that the strength of the trailing arm 1e is disadvantageous due to the increase in the opening area of the second opening 15e has also occurred.

The present invention was conceived under such circumstances, and manufactures a suspension of the type in which the ends of a torsion beam are inserted into two openings of a trailing arm in series and welded. In such a case, it is an object of the present invention to appropriately connect and fix the trailing arm and the torsion beam without causing any problems in the welding operation, the strength surface of each part, and the like.

[0010]

Means for Solving the Problems To solve the above problems, the present invention takes the following technical means.

That is, the present invention provides a torsion beam having a substantially V-shaped cross-section or a substantially U-shaped cross-section having an inclined upper piece and a lower piece and opened to the front or rear of the vehicle.
A trailing arm type suspension structure having a trailing arm in which a first opening and a second opening for inserting and welding the torsion beam into the inner surface and the outer surface in the vehicle width direction are formed. The angle between the upper piece and the lower piece of the torsion beam to be inserted into the second opening of the trailing arm is equal to that of the part to be inserted into the first opening of the trailing arm. It is characterized in that it is formed at an angle smaller than the mutual angle between the upper piece and the lower piece.

In the present invention, the angle between the upper piece and the lower piece of the torsion beam formed in a substantially V-shaped cross section or a substantially U-shaped cross section is not the same at various places. The angle of the portion to be inserted into the second opening is smaller than that of the portion to be inserted into the opening. Therefore, for example, in the case where the torsion beam is inserted near the rear end of the inner periphery of the first opening and the second opening of the trailing arm and connected, the rear portion of the torsion beam and the rear end of the inner periphery of the second opening are connected to each other. Even if there is a gap between the upper and lower portions of the torsion beam, the gap between the upper and lower portions of the torsion beam and the other portion of the peripheral portion of the second opening is the upper portion of the torsion beam. The smaller the angle between the lower part and the lower piece, the smaller the size. That is, when a gap of a certain size is formed between the rear end of the inner peripheral edge of the second opening and the rear of the torsion beam, the mutual angle between the upper and lower pieces of the torsion beam is reduced. This makes it possible to reduce the size of the gap formed between the upper and lower pieces of the torsion beam and the peripheral edge of the second opening, as compared with the case where the mutual angle is increased. The present invention is advantageous in that the upper and lower pieces of the torsion beam can be brought closer to the peripheral edge of the second opening.

As a result, in the present invention, when the contact area between the peripheral portion of the first opening and the torsion beam is set to be large, the upper and lower portions of the torsion beam are connected to the peripheral portion of the second opening. This makes it possible to avoid or suppress the difficulty in the work of welding to the workpiece. Therefore, a special effect of facilitating and ensuring the welding operation of the torsion beam and the trailing arm can be obtained.

[0014] In the present invention, the second opening formed in the outer side surface of the trailing arm in the vehicle width direction is formed by an angle between the upper piece and the lower piece of the torsion beam inserted into the second opening. Can be formed to have a small opening area. Therefore, the advantage that the strength of the trailing arm can be increased is also obtained.

Of course, in the present invention, the trailing arm and the torsion beam are welded at at least two predetermined positions on the inner and outer side surfaces of the trailing arm in the vehicle width direction. In addition, there is an advantage that the integration of the trailing arm and the torsion beam can be effectively achieved, the stress concentration on the welded portion can be reduced, and the connection strength between the trailing arm and the torsion beam can be increased.

[0016]

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 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 the main part. FIG. 3 is a cross-sectional view of FIG.
It is a principal part sectional drawing of a line. FIG. 4 is an enlarged side view of arrow I in FIG.

In FIG. 1, the trailing arm type suspension comprises a pair of right and left trailing arms 1 and 2.
1, a torsion beam 2 having both ends connected to the pair of trailing arms 1, 1 and a stabilizer 3
And the like. In FIG. 1,
The arrow N1 direction is the front of the vehicle, and the arrow N2 direction is the vehicle width direction.

A bush 10 for attaching the trailing arm 1 to a vehicle body frame (not shown) is provided at a front end of each of the trailing arms 1.
The entire trailing arm 1 can swing vertically about the mounting center C of the bush 10. At the rear end of the trailing arm 1, a spindle shaft 11 for mounting wheels is protruded, and a mounting seat 12 for mounting a suspension spring is provided as appropriate.

As shown in FIG. 2, the trailing arm 1 has an upper member 1a and a lower member 1b which are divided into upper and lower parts.
Are joined to form a so-called monaka-shaped hollow shape. The upper member 1a and the lower member 1b are formed by pressing (deep drawing) a metal plate, and have a lower peripheral portion of the upper member 1a and an upper peripheral portion of the lower member 1b. Flanges 13a, 13b for joining these two to each other
Are appropriately formed.

A first opening 14 and a second opening 15 for inserting the end of the torsion beam 2 in series are provided in the inner and outer side surfaces 1A and 1B of the trailing arm 1 in the vehicle width direction. ing. The first opening 14 is an opening formed by both the upper member 1a and the lower member 1b without providing the upper member 1a and the lower member 1b of the trailing arm 1 with the flanges 13a and 13b. . On the other hand, the second opening 15 is formed such that a part of the flange 13a of the upper member 1a is curved upward and a part of the lower flange 13b is curved downward, so that the two flanges 13a, 13b is formed as an opening whose outer periphery is surrounded. By forming these flanges 13a and 13b, the rigidity of the peripheral portion of the second opening 15 is sufficiently increased.

The torsion beam 2 has an inclined upper piece 21a and a lower piece 2 forming an opening 20 at the front side of the vehicle.
1b, and has a substantially V-shaped cross section or a substantially U-shaped cross section, and is formed by, for example, bending or bending a metal plate having a constant thickness. The torsion beam 2 extends in the vehicle width direction, and both end portions in the longitudinal direction of the torsion beam 2 extend through the inside of each trailing arm 1 along the vehicle width direction as shown in FIGS. 1 and 2. 1st first opening 1
4 and the second opening 15.

The inclination angles of the upper piece 21a and the lower piece 21b of the torsion beam 2 are not the same at all places, but are set as follows.

That is, in the torsion beam 2 drawn by the imaginary line in FIG.
The mutual angle with b is the angle θ1 for the fixed area A at the center in the longitudinal direction, while the fixed area B on the end side is an angle θ2 smaller than the above θ1. . The intermediate area C between the areas A and B has an angle θ
It has a tapered shape that gradually changes from 1 to an angle θ2.

In the regions A and B, the widths Sa and Sb of the torsion beam 2 in the longitudinal direction of the vehicle are also different.
The width Sb of the area B is smaller than the width Sa of the area A. Further, a flat portion 22 is formed at an appropriate position in the region A. The flat part 22 is provided with the torsion beam 2
Is used as a reference plane when welding to the trailing arm 1. If such a flat portion 22 is provided, the positioning accuracy of the torsion beam 2 with respect to the trailing arm 1 can be increased.

In the torsion beam 2, the area A is inserted into the first opening 14 of the trailing arm 1, and the area B is inserted into the second opening 15
Has been inserted. The first opening 14 and the second opening 15 of the trailing arm 1 are formed in an opening shape and size corresponding to the cross-sectional shape of each portion of the torsion beam 2 inserted into each of the openings 14 and 15.

The first opening 14 and the second opening 15 are provided with welds W1 and W2 at their peripheral edges for joining with the torsion beam 2. Specifically, in the first opening 14, the welding W <b> 1 is applied to substantially the entire periphery of the torsion beam 2 in contact with the outer surface. In the second opening 15, as shown in FIG. 4, a welding W2 is applied to a portion of the torsion beam 2 that comes into contact with each outer surface of the upper piece 21a and the lower piece 21b.

The stabilizer 3 is mounted to increase the so-called roll rigidity and reduce the rolling of the vehicle body. The torsion beam 2 exhibits a stabilizer function. However, the roll rigidity of the suspension can be further increased by additionally providing the stabilizer 3.

The stabilizer 3 is inserted into the second opening 15 through the first opening 14 of each trailing arm 1 in the same manner as the torsion beam 2. For example, as shown in FIG. 2 opening 2
0. The end of the stabilizer 3 is shown in FIG.
As shown in the figure, the trailing arm 1 is sandwiched between a pair of flanges 13a and 13b,
4a is fixedly attached to these flanges 13a, 13b by tightening.

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

First, in the suspension, it is necessary to reliably weld the peripheral portion of the first opening 14 of the trailing arm 1 to the torsion beam 2. For this purpose, as shown in FIG. Inner edge rear end portion 14a of the portion 14
It is desired to make the gap H between the torsion beam 2 and the rear portion 21c small, and then apply the welding W1 also to this position. On the other hand, when the torsion beam 2 is positioned with reference to the first opening 14 as described above, the second opening 1
In some cases, an error may occur in positioning the torsion beam 2 with respect to the beam 5. Specifically, in FIG. 4, a gap L may be generated between the rear end portion 15 a of the inner peripheral edge of the second opening 15 and the rear portion 21 c of the torsion beam 2.

However, in the above-mentioned suspension, even if the above-mentioned gap L occurs, the outer surfaces of the upper piece 21a and the lower piece 21b of the torsion beam 2 and the peripheral edge of the second opening 15 facing the same. The gap that occurs between
It can be small. That is, as shown in FIG. 5A, when the inner peripheral rear end portion 15a of the second opening 15 and the rear portion 21c of the torsion beam 2 are displaced by the dimension L in the vehicle front-rear direction, the torsion beam 2 The gap δ2 between the upper piece 21a and the inner peripheral edge of the second opening 15 facing the upper piece 21a is δ2 = L · sin θ2 / 2.

On the other hand, as shown in FIG. 5B, the mutual angle between the upper piece 21a and the lower piece 21b of the torsion beam 2 inserted into the second opening 15 is set to the first opening. 14 is formed at the same angle θ1 as the part to be inserted into the part 14 (a case corresponding to the prior art described in FIGS. 6 and 7)
, The gap δ1 between the upper piece 21a of the torsion beam 2 and the inner peripheral edge of the second opening 15 facing it is
δ1 = L · sin θ1 / 2. Here, since the torsion beam 2 is formed in the relationship of θ1> θ2 as described above, the relationship of the gaps δ1 and δ2 shown in FIG. 5 eventually becomes δ1> δ2.

As described above, after all, in the above suspension, the upper piece 21a and the lower piece 21b of the torsion beam 2 are formed.
Are not formed uniformly at various places, and the angle of the second opening 15 is larger than the angle θ1 of the portion to be inserted into the first opening 14.
The outer surface of the upper piece 21a and the lower piece 21b of the torsion beam 2 can be made closer to the peripheral edge of the second opening 15 by reducing the angle θ2 of the portion to be inserted into the torsion beam 2. As a result, it is possible to appropriately and surely perform the welding W2 of these portions.

The second opening 15 is formed at an angle θ2 between the upper piece 21a and the lower piece 21b of the torsion beam 2.
Is small, the opening height h can be reduced (see FIG. 4), and the opening can be formed with a small opening area. Therefore, the strength of the trailing arm 1 can be increased by the amount that the area of the opening formed in the trailing arm 1 can be reduced.

In the above suspension, the torsion beam 2 penetrates through the inside of the trailing arm 1 in the vehicle width direction, and the inner and outer side surfaces 1A, 1 of the trailing arm 1 are provided.
Welds W1 and W2 are performed at various points B. Therefore, even if a torsional 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 the suspension, the force concentrates on the position of the welding W1. And acts on the position of the other welding W2. Therefore, in the suspension, stress concentration at the position of the weld W1 can be made less likely to occur, and the strength of the entire suspension can be improved.

In the above embodiment, the second opening 15 is formed by using the flanges 13a and 13b of the upper member 1a and the lower member 1b that constitute the trailing arm 1. However, the present invention is not limited to this. In the present invention, the second opening 15 may be formed as an opening having a structure that does not use the flanges 13a and 13b. Further, the trailing arm 1 may be manufactured by appropriately using 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 configuration of each part such as the trailing arm and the torsion beam is not limited to the above-described embodiment, and various design changes are possible. For example, the direction of the torsion beam is reversed from that of the above-described embodiment so that the torsion beam having a substantially V-shaped cross section or a substantially U-shaped cross section opens toward the vehicle rear side.
A structure in which the torsion beam is inserted near the front ends of the inner peripheral edges of the first opening and the second opening may be connected. In addition, the specific numerical value of the mutual angle between the upper piece and the lower piece of the torsion beam is of course not limited.

[Brief description of the drawings]

FIG. 1 is a 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 a sectional view of a main part taken along line XX of FIG. 1;

FIG. 4 is an enlarged side view of an essential part of arrow I in FIG. 2;

FIGS. 5A and 5B are explanatory diagrams showing a gap generated between a second opening and a torsion beam; FIGS.

FIG. 6 is an essential part perspective view showing an example of a prior art of a trailing arm type suspension.

FIG. 7 is an enlarged side view of a main part taken along the arrow II of FIG. 6;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Trailing arm 1A Inner side surface part (of trailing arm) 1B Outer side surface part (of trailing arm) 2 Torsion beam 14 First opening 15 Second opening 20 Opening (of torsion beam) 21a Upper piece (of torsion beam) 21b Lower part (of torsion beam) W1, W2 Weld θ1, θ2 Angle between each other

────────────────────────────────────────────────── ─── Continuation of the front page (56) References German Patent Application Publication 2654132 (DE, A1) (58) Fields investigated (Int. Cl. ⁷ , DB name) B60G 9/04 B60G 7/00

Claims (1)

(57) [Claims] 1. An apparatus comprising: an inclined upper piece and a lower piece ;
A torsion beam having a substantially V-shaped cross section or a substantially U-shaped cross section opened to the front or rear of the vehicle, and an inner surface portion in the vehicle width direction and the like .
And welding by inserting the torsion beam into the outer surface
First and second openings are formed respectively.
And a trailing arm provided with a trailing arm, wherein the torsion beam has an upper part and a lower part which are inserted into the second opening of the trailing arm. The trailing arm suspension according to claim 1, wherein the angle is formed to be smaller than the mutual angle between the upper piece and the lower piece of the portion to be inserted into the first opening of the trailing arm. Construction.