JP4487830B2 - Torsion beam type rear suspension - Google Patents

Description

  The present invention relates to a torsion beam type rear suspension.

The torsion beam type suspension includes a torsion beam extending in the vehicle width direction and a pair of left and right arms extending in the longitudinal direction of the vehicle body, and has a structure in which an end of the torsion beam is connected to a central portion in the longitudinal direction of the arm. The torsion beam type suspension is typically widely used in the rear suspension of small FF vehicles. In this case, generally, as disclosed in Patent Document 1, the front end of the arm is connected to the vehicle body, A trailing arm type with a wheel attached to the rear end is adopted, and a coil spring is assembled. In order to mount this coil spring, a spring seat is disposed at a corner portion between the trailing arm and the torsion beam. This spring seat is generally fixed to a trailing arm (Patent Document 2).
No. 2001-321846 No. 2004-34866

  The running performance of the vehicle is greatly influenced by the so-called undercarriage rigidity. Therefore, in order to increase the rigidity of the suspension with the torsion beam type suspension, it is necessary to increase the rigidity of the spring seat and the trailing arm that supports the spring seat, but there is a limit. Further, when the rigidity of the spring seat and the trailing arm is inadvertently increased, the balance of the torsion beam type suspension including the torsion beam and the pair of left and right trailing arms may be lost.

  On the other hand, in order to increase the support rigidity of the spring seat, it can be considered that the spring seat is also carried by the torsion beam together with the trailing arm. However, in the torsion beam type suspension, the torsion beam has a main suspension function, so fixing the spring seat to the torsion beam may not only impair the function of the torsion beam but also cause stress concentration at the end of the torsion beam. There is.

  The object of the present invention is to provide an end of the torsion beam when the support rigidity of the spring seat with respect to the coil spring is improved without increasing the rigidity of the spring seat and the trailing arm by causing the spring seat to also bear the torsion beam. It is an object of the present invention to provide a torsion beam type rear suspension that can alleviate stress concentration that may occur in a part.

According to the present invention, such a technical problem is
A trailing arm that extends in the longitudinal direction of the vehicle body, has a front end pivotably supported by the vehicle body, and a bracket that rotatably supports a rear wheel at the rear end, the rear portion extending toward the bracket being a vehicle width A pair of left and right trailing arms extending obliquely outward in the direction;
Has a different shape cross-section, extends in the vehicle width direction, a torsion beam in the longitudinal direction of each end is connected to the front-rear direction central portion of the trailing arm,
A spring seat disposed at a corner portion between a longitudinal end portion of the torsion beam and a rear portion of the trailing arm and fixed to the torsion beam and the trailing arm, and having a coil spring mounting seat at the rear portion; A torsion beam type rear suspension ,
The spring seat is Rutotomoni that Yusuke and a bottom wall portion mounting seat of the coil spring is formed, the longitudinal flange formed by bending a rear end portion and the inward portion of the spring seat upward, The mounting seat of the coil spring is positioned at a position separated inward in the vehicle width direction from the trailing arm at the rear portion in the front-rear direction of the bottom wall portion,
Damper mounting bracket is attached to the rear portion of the front Kitate flange,
The damper mounting bracket is positioned at a position away from the trailing arm in the vehicle width direction in the same manner as the mounting seat of the coil spring,
In the spring seat, a front end edge of the vertical flange is fixed to the torsion beam, and a portion sandwiched between the vertical flange and the trailing arm among the portions opposed to the torsion beam is not to the torsion beam. This is accomplished by providing a torsion beam type rear suspension characterized by being fixed .

That is, according to the present invention, since the spring seat is fixed not only to the trailing arm but also to the torsion beam, it is not necessary to increase the rigidity of the spring seat and the trailing arm, and the support rigidity of the spring seat to the coil spring is increased. be able to. And since the site | part except the said vertical flange among the parts facing the torsion beam of a spring seat is not being fixed with respect to the torsion beam, the rigidity of the front-end part of a spring seat is comparatively weak. Therefore, it is possible to reduce the adverse effect of fixing the spring seat to the torsion beam with respect to the operation of the torsion beam, particularly the occurrence of stress concentration in the torsion beam.

  Further, in a preferred embodiment of the present invention, the vertical flange has a first flange portion extending in the longitudinal direction of the vehicle body, the front edge of which is fixed to the torsion beam, and is positioned at the rear end of the spring seat and extends in the vehicle width direction. A second flange portion fixed to the trailing arm, and the height of the second flange portion is greater than the height of the first flange portion. According to this, the rigidity of the front part of the spring seat fixed to the torsion beam is designed to be relatively low. Accordingly, it is possible to further reduce the occurrence of stress concentration at the end of the torsion beam as the spring seat is fixed to the torsion beam with respect to the operation of the torsion beam. This embodiment is effective when a coil spring mounting seat is provided at the rear portion of the spring seat, and the rigidity of the vicinity of the coil spring mounting seat is enhanced by a relatively high vertical flange.

  In a particularly preferred embodiment, in order to promote deformation of the front portion of the spring seat, an opening extending in a direction substantially parallel to the torsion beam, typically extending in the vehicle width direction, is provided at the front portion of the bottom wall portion of the spring seat. The deformation promoting part is formed.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings.

  FIG. 1 is a schematic plan view of a right end portion of a torsion beam suspension applied to a rear wheel of a vehicle. The torsion beam type rear suspension 1 has a pair of left and right trailing arms 2 extending in the longitudinal direction of the vehicle body and a torsion beam 3 extending in the vehicle width direction. Each end of the trailing arm 2 is attached to the longitudinal central portion 2a of the torsion beam 3. A pair of trailing arms 2 are connected to both ends of the torsion beam 3 by welding.

  Similar to the structure disclosed in Patent Document 1 (2001-321846), the torsion beam 3 has a closed cross section and a deformed cross section formed by pressing a hollow pipe. The shape of the odd-shaped cross section is, for example, a U shape that is open downward. At the longitudinal end portion of the torsion beam 3, the U-shaped cross section has a wide opening. , The opening of the U-shaped end face is narrowed. That is, the torsion beam 3 has a shape that gradually widens from the central portion in the longitudinal direction toward the end when viewed in plan, and the longitudinal end of the torsion beam 3 has a rear end compared to the front end. It has an inclined shape so as to be located outward in the width direction. In other words, the longitudinal end of the torsion beam 3 is designed so that the rear end overlaps with the trailing arm 2 more than the front end.

  The trailing arm 2 extending in the front-rear direction of the vehicle body has an eye 4 at the front end thereof, and the eye 4 is swingably supported by the vehicle body via a bush (not shown). The trailing arm 2 further has a bracket 5 at the rear end thereof, and a wheel (not shown) is rotatably supported via the bracket 5.

  As can be understood from FIG. 1, the trailing arm 2 has a curved shape that is concave outward in the vehicle width direction in a plan view. That is, when the trailing arm 2 is viewed in plan, the front portion 2b from the eye 4 to the front end of the central portion 2a extends obliquely inward in the vehicle width direction from the eye 4 toward the central portion 2a. The central portion 2a extends slightly inward in the vehicle width direction from the front end to the rear end, and the rear portion 2c from the rear end of the central portion 2a to the bracket 5 extends from the central portion 2a to the bracket 5. It has a shape extending greatly inclined outward in the vehicle width direction. FIG. 2 is a view of the torsion beam type suspension 1 as seen from the rear. As can be seen from FIG. 2, the trailing arm 2 has a shape extending obliquely upward from the central portion 2 a toward the bracket 5. ing.

  In the torsion beam type rear suspension 1, a spring seat 6 is disposed at a corner portion between the rear portion 2 c of the trailing arm 2 and each longitudinal end portion of the torsion beam 3.

  The spring seat 6 is formed by press forming a steel plate, and the spring seat 6 has a bottom wall 7. The torsion beam type rear suspension 1 includes a coil spring 8, and a mounting seat for the coil spring 8 is provided at the rear portion of the main bottom wall portion 7 a of the bottom wall 7 extending almost horizontally.

The bottom wall 7 has an inclined portion 7 b that is partitioned from the main bottom wall portion 7 a by a bent line 9 , and the inclined portion 7 b is positioned to face the rear end portion of the trailing arm 2. That is, the bending line 9 extends straight in the longitudinal direction of the vehicle body, and the front end of the bending line 9 is joined at the longitudinal intermediate portion of the rear portion 2 c of the trailing arm 2. The inclined portion 7 b of the spring seat 6 extends obliquely upward from the bent line 9 outward in the vehicle width direction, and the outer edge in the vehicle width direction is in contact with the trailing arm 2.

As described above, the mounting seat of the coil spring 8 is provided at the rear portion of the bottom wall 7 of the spring seat 6, and the rear portion of the bottom wall 7 includes an inclined portion 7 b fixed to the trailing arm 2 and The bending line 9 substantially increases the rigidity. Therefore, it is possible to ensure the support rigidity of the spring seat 6 with respect to the coil spring 8 without preparing another reinforcing member.

  The spring seat 6 has no flange on the outer edge in the vehicle width direction, and the outer edge in the vehicle width direction is welded to the trailing arm 2 in almost the entire region. That is, the outer edge 10 in the vehicle width direction of the bottom wall 7 including the inclined portion 7b of the spring seat 6 has a shape along the side surface of the rear portion 2c of the trailing arm 2, and the outer edge 10 of the spring seat 6 is It is welded to the trailing arm 2 over the entire area. Since the outer edge in the vehicle width direction in which the spring seat 6 is welded to the trailing arm 2 has no flange, the spring seat 6 moves to the trailing arm 2 as the spring seat 6 is welded to the trailing arm 2. Can be reduced.

  The spring seat 6 has a vertical flange 13 extending across the rear edge 11 and the vehicle width direction inner edge 12. That is, the vertical flange 13 extends in the vehicle width direction along the first flange portion 14 extending in the front-rear direction along the inner edge of the bottom wall 7 and the rear edge 11 of the main bottom wall portion 7a and the inclined portion 7b. The first and second flange portions 14 and 15 are continuous and formed by bending the spring seat 6 upward.

  The first flange portion 14 extending in the longitudinal direction of the vehicle body has a relatively small height dimension, while the second flange portion 15 positioned at the rear end portion of the spring seat 6 and extending in the vehicle width direction has a height dimension thereof. Is set relatively large. That is, the spring seat 6 is designed so that the rigidity of the part adjacent to the torsion beam 3 is relatively low, and the rigidity of the part adjacent to the mounting seat of the coil spring 8 is relatively high.

  The first flange portion 14 extending in the longitudinal direction of the vehicle body along the inner edge of the bottom wall 7 has a relatively low height, and is adjacent to the front end portion 14 a of the first flange portion 14, that is, the torsion beam 3. The portion extends upward and forward, and has a shape in which a front end edge thereof is in contact with the torsion beam 3. That is, the front end portion 14 a of the first flange 14 has a shape in which the upper edge is enlarged upward, and the front end edge has a curved shape cut out along the rear side surface of the torsion beam 3. The front end edge of the first flange 14 is fixed to the torsion beam 3 by welding the upper part thereof, that is, the part X surrounded by an ellipse in FIGS. 2 and 3, and the lower part is not fixed to the torsion beam 3.

  The upper end of the front edge of the first flange 14 is welded to the torsion beam 3, and the upper part welded to the torsion beam 3 extends obliquely outward in the vehicle width direction toward the front, and this extension The direction L1 is preferably substantially parallel to the axis L2 of the eye 4 of the trailing arm 2, that is, the imaginary line L3 orthogonal to the swing axis of the trailing arm 2. Moreover, it is preferable that the front end edge of the first flange 14 has a shape in which the upper part rides on the upper surface of the torsion beam 3. According to this, since the spring seat 6 is fixed in a state of being hooked on the torsion beam 3, the support of the spring seat 6 by the torsion beam 3 can be ensured.

  The front end edge of the main bottom wall portion 7a of the spring seat 6 has no flange, and extends in the vehicle width direction along the longitudinal end of the trailing arm 2. The front end edge 16 of the main bottom wall portion 7a is preferably located at a slight distance from the trailing arm 2. In this embodiment, the trailing edge 16 is provided between the spring seat 6 and the trailing arm 2. An elongated gap 17 extending along the arm 2 is formed.

  The vertical flange 13 formed along the inner edge and the rear edge of the spring seat 6 will be further described. The vertical flange 13 is a second flange portion 15 that is continuous with the first flange portion 14 having a relatively small height. Has a relatively large height dimension. The outer end edge in the vehicle width direction of the second flange portion 15 is positioned to face the side surface of the trailing arm 2 and is formed in a curved shape along the side surface of the trailing arm 2. That is, the outer edge in the vehicle width direction of the second flange portion 15 has no flange, and the outer edge in the vehicle width direction of the second flange portion 15 is welded to the trailing arm 2.

  In the drawing, reference numeral 18 denotes a damper mounting bracket, and the damper mounting bracket 18 is welded to the rear surface of the second flange 17 on the vehicle body. A tube type damper 19 is attached to the damper mounting bracket 18.

  The torsion beam type rear suspension 1 is preferably provided with an opening 20 as a means for reducing rigidity at the front end portion of the spring seat 6, that is, the front end portion of the main bottom wall portion 7a. It is preferable to extend in the vehicle width direction substantially parallel to the longitudinal direction of the torsion beam 3.

  It goes without saying that the torsion beam type suspension preferably functions effectively from one end to the other end of the torsion beam 3. In the rear suspension 1 of the embodiment, a vertical flange 13 formed by bending the spring seat 6 is used, and the front end edge extending in the vertical direction of the vertical flange 13 is fixed to the torsion beam 3 by welding. Therefore, adverse effects on the torsional deformation of the torsion beam 3 can be reduced. Of course, since the spring seat 6 is carried not only by the trailing arm 2 but also by the torsion beam 3, the support rigidity of the spring seat 6 can be increased without designing the rigidity of the trailing arm 2 and the spring seat 6 to be high. Can be improved.

  In other words, when the front edge of the spring seat 6, that is, the main bottom wall portion 7 a is fixed to the torsion beam 3, the movement of the longitudinal end of the torsion beam 3 is hindered by the spring seat 6, and the longitudinal end of the torsion beam 3 Since the suspension function is not substantially exhibited, not only the original function of the torsion beam suspension 1 including the pair of trailing arms 2 and the torsion beam 3 is impaired, but also the portion where the spring seat 6 of the torsion beam 3 is fixed. There is a risk that stress concentration occurs at the boundary with the inner portion in the vehicle width direction. On the other hand, in the embodiment, since the front end edge of the main bottom wall portion 7a of the spring seat 6 is not fixed to the torsion beam 3, the stress concentration can be reduced.

  In particular, as in the embodiment, since the upper part of the front end edge of the vertical flange 13 that is a part fixed to the torsion beam 3 is inclined forward in the vehicle width direction (L1 in FIG. 1), By combining the curved trailing arm 2 that is concave outward, it becomes easy to maintain the coupling strength between the spring seat 6 and the torsion beam 3 against the swinging of the trailing arm 2. In addition, it is possible to reduce the movement of the trailing arm 2 from inhibiting the movement of the torsion beam 3 via the spring seat 6.

  Similarly, the front portion of the main bottom wall portion 7a of the spring seat 6 is configured without a flange, and the height of the first flange portion 14 extending in the vehicle longitudinal direction of the vertical flange 13 is set to be relatively small, so that the spring seat Since the rigidity of the front portion of 6 is reduced, it is possible to reduce the movement of the trailing arm 2 from inhibiting the movement of the torsion beam 3 via the spring seat 6. This can be further assured by providing an opening 20 extending in the vehicle width direction in the front portion of the main bottom wall portion 7a to promote deformation of the front portion of the spring seat 6.

FIG. 3 is a schematic plan view showing only a right side portion of a torsion beam type rear suspension. FIG. 2 is a rear view of the torsion beam type rear suspension of FIG. 1. FIG. 2 is a view of the torsion beam type rear suspension of FIG. 1 as viewed from the inside in the vehicle width direction to the outside. FIG. 2 is a perspective view of the torsion beam type rear suspension of FIG. 1 viewed from the inside in the vehicle width direction to the outside.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Torsion beam type rear suspension 2 Trailing arm 2a Central part of trailing arm 2b Front part of trailing arm 2c Rear part of trailing arm 3 Torsion beam 6 Spring seat 7 Bottom wall of spring seat 8 Coil spring 13 Vertical flange 14 Vertical flange First flange portion 15 Second flange portion of the vertical flange 16 Front edge of the spring seat 17 Gap between the spring seat and the trailing arm 20 Deformation promoting opening

Claims (6)

A trailing arm that extends in the longitudinal direction of the vehicle body, has a front end pivotably supported by the vehicle body, and a bracket that rotatably supports a rear wheel at the rear end, the rear portion extending toward the bracket being a vehicle width A pair of left and right trailing arms extending obliquely outward in the direction;
Has a different shape cross-section, extends in the vehicle width direction, a torsion beam in the longitudinal direction of each end is connected to the front-rear direction central portion of the trailing arm,
A spring seat provided at a corner portion between a longitudinal end portion of the torsion beam and a rear portion of the trailing arm and fixed to the torsion beam and the trailing arm and having a coil spring mounting seat at the rear portion; A torsion beam type rear suspension ,
The spring seat is Rutotomoni that Yusuke and a bottom wall portion mounting seat of the coil spring is formed, the longitudinal flange formed by bending a rear end portion and the inward portion of the spring seat upward, The mounting seat of the coil spring is positioned at a position separated inward in the vehicle width direction from the trailing arm at the rear portion in the front-rear direction of the bottom wall portion,
Damper mounting bracket is attached to the rear portion of the front Kitate flange,
The damper mounting bracket is positioned at a position away from the trailing arm in the vehicle width direction in the same manner as the mounting seat of the coil spring,
In the spring seat, a front end edge of the vertical flange is fixed to the torsion beam, and a portion sandwiched between the vertical flange and the trailing arm among the portions opposed to the torsion beam is not to the torsion beam. Torsion beam type rear suspension characterized by being fixed . The mounting position of the damper mounting bracket with respect to the spring seat overlaps with the mounting seat of the coil spring when viewed from the rear of the vehicle body, whereby the damper mounting bracket is similar to the mounting seat of the coil spring. 2. The torsion beam type rear suspension according to claim 1, wherein the torsion beam type rear suspension is positioned at a position distant from the trailing arm inward in the vehicle width direction. 3. The torsion beam type rear suspension according to claim 1 , wherein an opening is formed in the spring seat between a front end edge of the bottom wall portion and the coil spring mounting seat . The vertical flange includes a first flange portion extending in a vehicle front-rear direction whose front end edge is fixed to the torsion beam, and a first flange portion positioned at the rear end of the spring seat and extending in the vehicle width direction and fixed to the trailing arm. and a second flange portion, torsion beam type rear suspension according to claim 1 or 2 height of the second flange portion being greater than the height of the first flange portion. The torsion beam type rear suspension according to claim 4 , wherein a deformation promoting portion extending substantially parallel to the torsion beam is formed at a front portion of the bottom wall portion of the spring seat. The torsion beam type rear suspension according to claim 5 , wherein the deformation promoting portion is an opening extending substantially parallel to the torsion beam.

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