JP2001088525A - Torsion beam type suspension structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a torsion beam type suspension structure that can efficiently have rigidity against rolling as a stabilizer function with a small number of part items. SOLUTION: A plate member 7 extending in the cross direction of a vehicle is disposed in a torsion beam 6, and both end parts of the plate member 7 are formed as inner reinforcing members 7a. Both cross direction sides of the plate member 7 are fixed to the inner surface of the torsion beam 6. The rigidity of the torsion beam 6 can thereby be improved over the whole length.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a torsion beam type suspension structure for a vehicle.

[0002]

2. Description of the Related Art A conventional torsion beam type suspension structure is constructed by, for example, rigidly connecting both ends of a torsion beam extending in a vehicle width direction to side surfaces of a trailing arm. In this torsion beam type suspension structure, the up-and-down movement of the wheels in the left and right opposite directions is absorbed by the torsion beam torsion, so that the roll rigidity can be adjusted by the torsion beam.
The torsion beam has an open cross-sectional shape having a substantially U-shaped cross section, and the open direction of the open cross section is set downward, forward of the vehicle, or the like.

Further, when the torsion beam is twisted or subjected to a longitudinal force, stress concentrates on the joint between the end of the torsion beam and the trailing arm. Therefore, as shown in FIG. At both ends of the torsion beam 50, reinforcing members 52 and 53 connected to the trailing arm 51 are provided outside and inside the ends, respectively.

Further, in order to increase the roll rigidity of the vehicle, a stabilizer made of a round bar may be provided separately from the torsion beam 50. For mounting the above-mentioned conventional stabilizer, for example, separately from the torsion beam 50, the stabilizer is extended in the vehicle width direction outside the torsion beam 50, and both ends of the stabilizer are rigidly connected to the left and right trailing arms, respectively. Or the torsion beam 5 as shown in FIG.
This is performed by arranging the stabilizer 54 so as to penetrate the inside thereof, and rigidly connecting both ends of the stabilizer 54 only to the left and right trailing arms 51 respectively.

[0005]

However, separately arranging the stabilizer 54 on the outside of the torsion beam 50 imposes restrictions on the layout due to the arrangement that avoids interference with parts around the gas tank and the floor. However, particularly in a compact car, there is a problem that it is difficult to establish a layout.

When the stabilizer 54 is arranged in the hollow torsion beam 50, the stabilizer 54 is separated from the inner surface of the torsion beam 50 so that the stabilizer 54 does not interfere with the inner surface of the torsion beam 50, although there is no problem in the above layout. The stabilizer 54 is arranged on the opening side of the substantially U-shaped cross section, and is inevitably arranged away from the top of the U-shaped cross section. Here, as shown in FIG. 12, since the shear center S1 of the torsion beam 50 itself is near the top P, conventionally, the shear center S4 of the torsion beam 50 and the shear center S4 of the stabilizer 54 are different from each other. Departure, Stabilizer 5
4, the positions of the shear centers S5 and S1 of the torsion beam 50 including the stabilizer 54 greatly differ, and the alignment such as the roll steer and the camber characteristics of the suspension differs depending on the presence or absence of the stabilizer 54. Absent.

Further, for example, when the stabilizer 54 is disposed in the torsion beam 50, the inner reinforcing member 53 provided in the torsion beam 50 among the reinforcing members 52 and 53 connecting the trailing arm 51 and the end of the torsion beam 50 is used. However, the positions of the stabilizer 54 and the end of the stabilizer 54 joined to the trailing arm 51 interfere with each other so as to intersect with each other. For this reason, conventionally, when the stabilizer 54 is arranged in the torsion beam 50, the inner reinforcing member 53 is omitted, and the stress concentration at the end of the torsion beam 50 is reduced.
A corresponding technique is adopted by setting the roll rigidity high by increasing the plate thickness of the torsion beam 50.
However, when this method is employed, there is a problem that the weight increases and the cost increases.

An object of the present invention is to provide a torsion beam type suspension structure capable of efficiently providing a roll rigidity as a stabilizer function with a small number of parts by focusing on the above problems. .

[0009]

In order to solve the above-mentioned problems, the invention described in claim 1 of the present invention comprises a pair of arms arranged on both sides in the vehicle width direction, and a pair of arms extending in the vehicle width direction. A torsion beam connecting the pair of arms to form an open section having a substantially U-shaped cross section, and left and right inner reinforcing members disposed on the inner surface side of the torsion beam and connecting each end of the torsion beam and the arm. And a connecting member extending in the torsion beam along the torsion beam and having both ends integrally connected to the left and right inner reinforcing members, respectively. .

Next, according to a second aspect of the present invention, in the second aspect of the present invention, the connecting member comprises a flat plate-like member extending in the vehicle width direction and extending in the vehicle width direction. Both ends in the width direction of the member are fixed to the inner surface of the torsion beam, respectively. Next, the invention described in claim 3 is different from the configuration described in claim 2 in that the left and right reinforcing members and the connecting member are configured by a single plate member extending in the vehicle width direction. It is a feature.

Next, according to a fourth aspect of the present invention, in addition to the configuration of the first aspect, the left and right reinforcing members and the connecting member are formed of a single pipe member, and both end portions of the pipe member are provided. Is processed into a flat shape to form left and right inner reinforcing member portions. Next, the invention described in claim 5 is characterized in that the connecting member of the pipe member is fixed to the inner surface of the torsion beam in the structure described in claim 4.

[0012]

According to the first aspect of the present invention, the connecting member connecting the left and right inner reinforcing members becomes a member constituting the stabilizer, and the required torsional rigidity can be obtained without disposing the stabilizer outside the torsion beam. Stabilizer function eliminates restrictions on stabilizer layout, and at the same time, inner reinforcing members are arranged at both ends of the torsion beam, and the thickness of the torsion beam needs to be increased in order to increase the roll rigidity as before. There is an effect that there is no.

At this time, when the invention according to claim 2 is adopted, the connecting member is formed of a flat plate-like member, and the weight of the connecting member is reduced. Further, even if the connecting member is formed of a plate-shaped member and the torsional rigidity of the connecting member alone is low, by fixing both sides in the width direction of the connecting member to the torsion beam, the connecting member and the left and right inner reinforcing members and the torsion beam can be used. As a result, a closed cross section or a shape close to a closed cross section is formed over the entire length of the torsion beam. As a result, the torsional rigidity of the torsion beam is set efficiently and effectively high while suppressing a weight increase over the entire length. It is possible to add a stabilizer function. In the present invention, the stabilizer function is not provided solely by the connecting member, but a stabilizer function having required rigidity is secured by combination with a torsion beam. Further, from the above, since the rigidity is continuously set to be high over the entire length of the torsion beam, even when a torsion is input, when viewed along the longitudinal direction, the portion where the stress locally changes suddenly is seen. Is prevented from occurring,
This is advantageous for the durability of the torsion beam.

Further, in the present invention, by positively abutting both ends in the width direction of the connecting member to the inner surface of the torsion beam, it becomes possible to bring the shear center of the connecting member closer to the shear center of the torsion beam. The center and the shear center synthesized by both the torsion beam and the connecting member approach each other, and even if the roll rigidity is adjusted depending on the presence or absence of the connecting member, the tendency of the roll steer and the camber characteristics of the suspension are similar, As a result, the suspension alignment conditions can be shared. That is, versatility is improved.

Further, when the invention according to claim 3 is adopted,
In addition to the above effects, the left and right inner reinforcing members and the connecting member are formed of a single plate member, so that the number of parts can be reduced. Further, when the invention according to claim 4 is adopted, similarly to claim 3, the left and right inner reinforcing members and the connecting member are formed of one pipe material, and the effect that the number of parts can be reduced can be achieved. is there. This has the effect that the roll stiffness can be effectively improved with a small amount of material, that is, a small increase in weight.

[0016] By processing both ends of the pipe material into a flat shape, it becomes possible to form a conventional inner reinforcing member. Furthermore, when processing a pipe material, the torsional rigidity as a stabilizer function can be changed only by adjusting the cross-sectional shape of the connecting member portion of the pipe material. That is,
There is an effect that the torsional rigidity can be easily adjusted only by adjusting the processing conditions for the same pipe material. In addition,
In the present invention, the pipe member itself has a required torsional rigidity because it has a closed cross-sectional shape by itself.

At this time, when the invention according to claim 5 is adopted, the pipe member is positively fixed to the inner surface of the torsion beam, so that the shear center of the connecting member portion approaches the shear center of the torsion beam, and the shearing of the torsion beam alone is performed. The center and the shear center synthesized by both the torsion beam and the pipe material are close to each other, and even if the rigidity is adjusted by the presence or absence of the pipe material, the tendency of the roll steer and camber characteristics of the suspension are approximated and the suspension is approximated. Adjustment conditions can be shared.

In addition, the pipe material itself has a hollow closed cross-sectional shape to secure required rigidity, and depending on how the pipe material is fixed to the inner surface of the torsion beam (method of fixing both sides in the vehicle longitudinal direction). Another closed section is also formed between the outer surface of the pipe material and the inner surface of the torsion beam, so that the torsional rigidity can be further improved. Further, by fixing the pipe material to the torsion beam, the torsion of the pipe material is prevented from being concentrated on a part (end) of the torsion beam.

[0019]

Next, a first embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a perspective view showing a torsion beam type rear suspension structure according to the present embodiment. In the suspension according to the present embodiment, as shown in FIG. 1, trailing arms 1 are arranged on both sides in the vehicle width direction. Each trailing arm 1 extends in the front-rear direction of the vehicle, and has a front end connected to a vehicle body-side member (not shown) via a bush 2, and a wheel support member 3 and a shock absorber 4 at the rear end. Is located at the bottom. Reference numeral 5 denotes a bracket on which a lower portion of the suspension coil is arranged.

The pair of trailing arms 1
Are connected by a torsion beam 6 extending in the vehicle width direction. As shown in FIG. 2, the torsion beam 6 has an open U-shaped cross section and opens downward. Both ends of the torsion beam 6 are welded to the inner surface of the trailing arm 1, respectively.

Both ends of the torsion beam 6 are reinforced by being connected to the trailing arm 1 by an inner reinforcing member 7a disposed inside the torsion beam 6 and an outer reinforcing member 8 disposed on the outer surface of the torsion beam 6. . The left and right inner reinforcing members 7a of the present embodiment are similar to those of FIG.
As shown in FIG. 1, the left and right ends of a plate-like member 7 formed by integrally pressing a single plate extending in the vehicle width direction. An intermediate portion connecting the left and right inner reinforcing member portions 7a constitutes a plate-like connecting member 7b. In the present embodiment, the connecting member portion 7b is pressed into a downwardly convex arc-shaped cross section. The left and right ends are formed in the same shape as the conventional inner reinforcing member 7a.

Then, the inner reinforcing member portions 7a formed at both end portions of the plate-like member 7 are formed in the same manner as in the prior art.
It is welded to the inner surface of the end of the torsion beam 6 and fixed to the trailing arm 1 by welding. As shown in FIG. 2, both ends of the connecting member 7 b in the width direction are fixed to the inner surface of the torsion beam 6 by welding.
The welding may be performed continuously along the longitudinal direction, or may be performed at predetermined intervals.

Next, the operation, effects and the like of the torsion beam type suspension structure having the above configuration will be described. In the structure of the torsion beam 6 of the present embodiment, the plate-shaped member 7 and the torsion beam 6 form a closed cross-sectional structure (box structure) over the entire length in the vehicle width direction, so that the torsional rigidity of the torsion beam 6 is improved. It has a stabilizer function. Thus, by providing the plate-shaped member 7,
By providing the torsion beam 6 with a function as a stabilizer, the roll rigidity can be adjusted without separately arranging a stabilizer outside the torsion beam 6.

Further, the plate-like member 7 is formed with a top P having a substantially U-shaped cross section.
, The shear center S2 of the plate member 7 itself becomes the shear center S1 of the torsion beam 6 itself.
, And even if the plate-shaped member 7 is provided to improve the rigidity, the shear center S3 obtained by combining the plate-shaped member 7 and the torsion beam 6 is equal to the shear center S1 of the torsion beam 6 alone when the plate-shaped member 7 is not provided. Located nearby. As a result, even if the torsional rigidity is adjusted with or without the plate-shaped member 7, a large difference in suspension alignment conditions such as roll steer and camber characteristics of the suspension is prevented, and a large change in suspension alignment is prevented. Has been versatile.

Moreover, although the torsional rigidity of the plate-shaped member 7 alone is low, the required torsional rigidity of the stabilizer is secured by forming a closed section with the torsion beam 6 as described above. That is, the torsional rigidity can be effectively improved while suppressing an increase in weight. The left and right ends of the plate-like member 7 form the components of the stabilizer, and at the same time serve as inner reinforcing members for increasing the rigidity of attaching the end of the torsion beam 6 to the trailing arm 1 as in the prior art. Demonstrate.
That is, by providing the one plate-shaped member 7, the left and right inner reinforcing members 7 a are provided and the stabilizer function can be given to the torsion beam 6, so that the number of parts can be reduced.

Further, as a result of setting the rigidity continuously high over the entire length of the torsion beam 6, the occurrence of local and sudden stress changes is prevented. In the related art, there is a possibility that a sudden change in stress may occur at a point where a transition from a portion reinforced by the reinforcing members 7a and 8 to a portion without the reinforcing members 7a and 8 (a portion B in FIG. 1) occurs. is there.

Here, the cross-sectional shape of the connecting member portion 7b is not limited to a downwardly convex arc shape, but may be processed into an upwardly convex arc shape as shown in FIG. 4 or as shown in FIG. It may be processed into a flat plate shape. FIG. 5 illustrates a case where a flange is provided at an end in the width direction to facilitate fixing to the inner surface of the torsion beam 6. As described above, by adjusting the cross-sectional shape at the time of press working, the closed cross-sectional shape is changed, and the torsional rigidity of the stabilizer is changed.

Next, a second embodiment will be described with reference to the drawings. The same members as those in the above embodiment will be described with the same reference numerals. The suspension structure of the present embodiment is the same as that of the first embodiment, except that a pipe member 10 is used instead of the plate member 7. That is, as shown in FIG.
The pipe members 10 are disposed in the torsion beam 6 instead of the plate-like members as the inner reinforcing member portions, respectively, by completely crushing the both end portions 10a.

However, the connecting member 10b is not in contact with the torsion beam 6, as shown in FIG. Other configurations are the same as in the first embodiment. In the present embodiment, the pipe material itself constitutes a stabilizer. Further, the left and right inner reinforcing members and the stabilizer constituent members (connecting members) are constituted by one pipe member 10, and the number of parts is reduced.

However, in this embodiment, there is a disadvantage that the shear center of the pipe member 10 is separated from the shear center of the torsion beam 6 as compared with the first embodiment. Also,
There is a disadvantage that the torsional stress as a stabilizer is concentrated on the end of the torsion beam 6 in the torsion beam 6. However, in the present embodiment, the end 10a of the pipe member 10 is flattened to serve as an inner reinforcing member, and thus has the same reinforcing effect as providing two layers of the inner reinforcing member.

In this embodiment, the torsional rigidity of the stabilizer can be easily adjusted by changing the cross-sectional shape of the connecting member portion 10b other than the end portion 10a of the pipe member 10. An example for solving the above disadvantage will be described below. In the present embodiment, as shown in FIG.
Other than the end of the pipe member 10, both sides in the vehicle width direction are fixed to the inner surface of the torsion beam 6 by welding. Other configurations are the same as those of the above embodiment.

As a result, the connecting member portion 10b of the pipe member 10 is positively brought into contact with the torsion beam 6, and the shear center of the pipe member 10 approaches the shear center of the torsion beam 6, thereby achieving the effect described in the first embodiment. Demonstrate. Further, as a result of the closed cross-sectional structure also being formed by the upper outer surface of the pipe member 10 and the torsion beam 6, the torsion beam 6 also becomes a member constituting a stabilizer over the entire length, and the above problem is solved. Moreover, in the present embodiment, a closed cross-sectional structure having two closed spaces is provided, so that torsional rigidity can be set higher than in the first embodiment.

Here, the processing of the pipe material 10 is not limited to the above-mentioned shape, but may be, for example, a shape as shown in FIG. 9, and may be determined according to the torsional rigidity of the stabilizer to be set. Further, in all the above embodiments, the left and right inner reinforcing members 7a and 10a and the connecting members 7b and 10b
Although the case where it is configured by one component is illustrated, the present invention is not limited to this. Separately prepare a connecting member made of a pipe material or the like that connects the left and right inner reinforcing members, and integrally connect both ends of the connecting member to the left and right inner reinforcing members by welding or bolting respectively. It may be constituted by. In this case, the connecting member functions as a stabilizer. Even in this case, although the connecting member is formed of a plate-like member and both ends in the width direction are fixed to the inner surface of the torsion beam 6, the number of components cannot be reduced, but each of the above-described effects can be achieved. Can have.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a torsion beam type suspension according to an embodiment of the present invention.

FIG. 2 is a sectional view taken along line AA in FIG.

FIG. 3 is a perspective view showing a plate member.

FIG. 4 is a diagram showing another cross-sectional shape of the connecting member.

FIG. 5 is a view showing another cross-sectional shape of the connecting member.

FIG. 6 is a view showing a pipe member according to a second embodiment of the present invention.

FIG. 7 is a sectional view showing an arrangement of a connecting member of a pipe member according to a second embodiment of the present invention.

FIG. 8 is a sectional view showing another arrangement of a connecting member of a pipe member according to a second embodiment of the present invention.

FIG. 9 is a cross-sectional view showing another shape of the connecting member portion.

FIG. 10 is a partially enlarged view showing a reinforcing member.

FIG. 11 is a diagram showing an example of arrangement of a conventional stabilizer.

FIG. 12 is a diagram for explaining a conventional problem.

[Explanation of symbols]

 Reference Signs List 1 trailing arm 6 torsion beam 7 plate member 7a inner reinforcing member 7b connecting member portion 8 outer reinforcing member 10 pipe material 10a inner reinforcing member portion 10b connecting member portion S1 shear center of torsion beam S2 shear center of connecting member S3 synthetic shear center

Claims (5)

[Claims] 1. A pair of arms arranged on both sides in the vehicle width direction, a torsion beam extending in the vehicle width direction and connecting the pair of arms to form an open section having a substantially U-shaped cross section, and a torsion beam. A torsion beam type suspension structure including left and right inner reinforcing members that are arranged on the inner surface side and connect each end of the torsion beam and the arm, respectively, wherein the inside of the torsion beam extends along the torsion beam and both ends thereof are A torsion beam type suspension structure comprising a connecting member integrally connected to the left and right inner reinforcing members. 2. The connecting member is composed of a plate-like member extending in the vehicle width direction and flat in a plan view, and both end portions in the width direction of the plate-like member are fixed to the inner surface of the torsion beam, respectively. The torsion beam type suspension structure according to claim 1. 3. The torsion beam type suspension structure according to claim 2, wherein the left and right reinforcing members and the connecting member are constituted by a single plate member extending in the vehicle width direction. 4. The left and right reinforcing members and the connecting member are formed of a single pipe material, and both ends of the pipe material are processed into a flat shape to form left and right inner reinforcing member portions. The torsion beam type suspension structure according to claim 1. 5. The torsion beam type suspension structure according to claim 4, wherein the connecting member of the pipe member is fixed to an inner surface of the torsion beam.