JP5691094B2 - Vehicle suspension structure - Google Patents

Description

  The present invention includes a pair of left and right trailing arms and a torsion beam having a U-shaped or V-shaped cross-sectional shape, and the torsion beam includes beam end surfaces formed at both longitudinal ends thereof. The present invention relates to a vehicle suspension structure in which both end portions in the longitudinal direction are welded and fixed to the outer peripheral surfaces of the pair of left and right trailing arms.

  In the above vehicle suspension structure, conventionally, as shown in FIG. 6, the longitudinal direction end of the torsion beam 2 having a U-shaped or V-shaped cross-sectional shape is applied to the outer peripheral surface of the trailing arm 1. A longitudinal end portion of the torsion beam 2 is fixed by forming a build-up 14 by welding on the outer peripheral surface of the trailing arm 1 (see, for example, Patent Document 1).

JP 2005-8123 A

  However, in the above vehicle suspension structure, the torsion beam 2 has a U-shaped or V-shaped cross-sectional shape, so that the longitudinal direction end of the torsion beam 2 is merely applied to the outer peripheral surface of the trailing arm 1. As shown in FIG. 6 (c), the corner 16 where the beam end surface 10 formed at the longitudinal end of the torsion beam 2 intersects the outer peripheral surface of the torsion beam 2 is in line contact with the outer peripheral surface of the trailing arm 1. Thus, there is a problem that it is difficult to bring the beam end surface 10 into surface contact with the outer peripheral surface of the trailing arm 1.

  Therefore, as in the prior art, the longitudinal end of the torsion beam 2 is welded to the outer peripheral surface of the trailing arm 1 while the longitudinal end of the torsion beam 2 is applied to the outer peripheral surface of the trailing arm 1. If fixed, a gap 17 may be formed between the beam end face 10 and the trailing arm 1 at the welded portion, as shown in FIG.

  If a gap 17 is formed between the beam end face 10 and the trailing arm 1 at the welded portion, the fixing strength along the welded portion between the torsion beam 2 and the trailing arm 1 varies, and the torsional reaction force of the torsion beam 2 is reduced. It may be difficult to transmit to the trailing arm 1 in a well-balanced manner, and stress concentration points may easily occur.

As a result, it is difficult to stably torsionally deform the torsion beam 2, and as shown in FIG. 6D, the trailing arm 1 is also easily twisted or bent along with the torsional deformation of the torsion beam 2. There is a possibility that the torsional performance is lowered and the steering stability is lowered.
In addition, cracks or the like may easily occur starting from the stress concentration location.

  In order to prevent these phenomena, a reinforcing member is separately provided, the thickness of the torsion beam 2 and the trailing arm 1 is increased, or the end surface of the torsion beam is machined obliquely so as to be in surface contact with the trailing arm. If this measure is taken, there is a risk that the weight and manufacturing cost increase and productivity decreases.

  The present invention has been made in view of the above circumstances, and while suppressing a decrease in productivity due to an increase in weight and manufacturing cost, it is possible to improve the torsional performance of the torsion beam and improve steering stability, such as cracks An object of the present invention is to provide a vehicle suspension structure that is less likely to cause the occurrence of the above.

The vehicle suspension structure according to the present invention is characterized in that a U-shaped or V-shaped cross section is disposed between a pair of left and right trailing arms and an opening upward or downward between the pair of left and right trailing arms. A torsion beam having a shape, and at least an outer peripheral surface on a side to which the torsion beam is fixed is formed in an arc shape along the longitudinal direction in plan view, and the torsion beam has both ends in the longitudinal direction. comprising a beam end face formed at the section, the beam end surface, the is formed in a shape along the cross-sectional shape of the trailing arm in the longitudinal direction as viewed in the trailing arm, on the outer peripheral surface, the beam end face convex portion or concave portion having opposed possible contact surface, in side view of the vehicle, so as to face in the longitudinal direction of the vehicle, and those wherein Bee Is formed along a longitudinal direction of the arm end faces, each of the longitudinal ends of the torsion beam, the disposed between the convex portion or concave portion facing, is pre-Symbol the contact surface and the surface contact with each other with the beam edge The welding is fixed to the outer peripheral surfaces of the pair of left and right trailing arms.

In the suspension structure for a vehicle of this configuration, a convex surface portion or a concave surface portion having a contact surface that can be opposed to the beam end surface is arranged on the outer peripheral surface of the trailing arm so as to face the vehicle front-rear direction in the vehicle side view. and it is formed along a longitudinal direction of this the beam edge, each of the longitudinal end portions of the torsion beam is disposed between the convex portion or concave portion facing and the contact surface between the beam end surface brought into surface contact with each other These are fixed to the outer peripheral surfaces of the pair of left and right trailing arms by welding.

  For this reason, even if each of the longitudinal ends of the torsion beam is fixed by welding to the outer peripheral surface of the pair of left and right trailing arms, there is little possibility of forming a gap between the beam end surface and the trailing arm. Variations in the fixing strength along the welded portion with the ring arm are unlikely to occur, and stress concentration points are also difficult to form.

  Therefore, the torsional reaction force of the torsion beam can be easily transmitted to the trailing arm along the welded portion of the torsion beam and the trailing arm, and the torsional reaction force is in surface contact with the contact surface of the convex or concave portion. It is easily received by the trailing arm via the beam end surface and transmitted to the trailing arm, and cracks are not easily generated.

  In addition, the convex surface or the concave surface is formed along the longitudinal direction of the beam end surface, that is, the torsion beam torsion direction, and the torsion beam is welded and fixed to the trailing arm. The trailing arm can be received in a well-balanced manner along the direction, and the torsional deformation of the trailing arm is hardly caused by the torsional deformation of the torsion beam.

  As a result, the torsion beam can be used without taking measures such as providing a reinforcing member separately, increasing the thickness of the torsion beam and the trailing arm, or machining the end surface of the torsion beam obliquely so that the end surface of the torsion beam is in surface contact with the trailing arm. Can be stably torsionally deformed, and torsional deformation of the trailing arm can be prevented.

  Furthermore, since the torsion beam and the trailing arm are welded with the beam end face in contact with the contact surface of the convex surface or the concave surface, when the torsion beam and the trailing arm are assembled (temporary assembly). By making the beam end surface and the contact surface of the convex surface portion or the concave surface surface contact each other, the relative position can be easily positioned with high accuracy.

  Therefore, with the vehicle suspension structure of this configuration, it is possible to improve the torsion performance of the torsion beam and improve the steering stability while suppressing the decrease in productivity due to the increase in weight and manufacturing cost, and cracks and the like are generated. There is little fear.

It is a side view which shows the rear part of the vehicle which has the suspension structure for vehicles by this invention. 1 is a side view showing a vehicle suspension structure according to the present invention. 1 is a perspective view showing a vehicle suspension structure according to the present invention. The welding fixing part of a torsion beam and a trailing arm is shown, (a) is a perspective view showing a state where the torsion beam is attached to the trailing arm (temporary assembly state), and (b) is a state where the torsion beam is fixed to the trailing arm by welding. (C) is the IVc-IVc sectional view taken on the line in FIG.4 (b) which shows the welding part of a torsion beam and a trailing arm. The welding fixing part of the torsion beam and the trailing arm in the second embodiment is shown, (a) is a perspective view showing a state (temporary assembly state) in which the torsion beam is assembled to the trailing arm, and (b) is the torsion beam being the trailing arm FIG. 5C is a cross-sectional view taken along line Vc-Vc in FIG. 5B showing a welded portion between the torsion beam and the trailing arm. FIG. 6A is a plan view showing a vehicle suspension structure, FIG. 6B is a side view showing the vehicle suspension structure, and FIG. 6C shows a welded portion between the torsion beam and the trailing arm. (D) is a side view showing a state in which the trailing arm is twisted or bent in accordance with torsional deformation of the torsion beam.

Embodiments of the present invention will be described below with reference to the drawings.
[First Embodiment]
FIG. 1 shows a rear portion of a vehicle having a vehicle suspension structure according to the present invention.
As shown in FIGS. 2 and 3, the vehicle suspension structure includes a pair of left and right trailing arms 1 and a torsion beam 2 connected by welding across the pair of left and right trailing arms 1.

Each trailing arm 1 is formed by bending a steel plate so that the cross-sectional shape of the intermediate portion in the longitudinal direction is formed in a substantially circular pipe shape and extends in the front-rear direction of the vehicle body.
An annular bush 3 is provided at the front of each trailing arm 1 to support the body frame so as to be swingable about the axis X.
At the rear part of the trailing arm 1, an end plate 5 for connecting the spindle 4 a of the wheel 4, a spring receiving member 7 for attaching the spring 6, and a support bracket 9 connected to the shock absorber 8 are provided. ing.

  The torsion beam 2 is formed by bending a substantially rectangular steel plate along the longitudinal direction with a press machine in order to ensure bending rigidity and torsional rigidity, and a pair of extending portions extending on both sides thereof. 2b, and is formed so as to have a U-shaped or V-shaped cross-sectional shape that is open on one side along the longitudinal direction.

  Each of both ends in the longitudinal direction of the torsion beam 2 is formed in a shape along the outer shape of the trailing arm 1 (substantially arc shape in the longitudinal direction of the trailing arm 1), and the bent portion 2a is formed with respect to the trailing arm 1. The pair of extending portions 2b are welded and fixed to the outer peripheral surface of the pair of left and right trailing arms 1 in the longitudinal direction in an attitude of being positioned upward and opening downward.

  Therefore, as shown in FIG. 2, the torsion beam 2 includes beam end faces 10 formed in a downward U-shape or V-shape in the longitudinal direction of the torsion beam 2 at both longitudinal ends.

  Both ends in the longitudinal direction of the torsion beam 2 are formed by punching a steel plate before bending so as to have a developed shape of the beam end face 10 and then bending the steel plate. Therefore, the beam end face 10 is formed substantially perpendicular to the inner peripheral face of the torsion beam 2.

As shown in FIG. 4, a convex surface portion 12 having a contact surface 11 that can be opposed to an end surface portion 10 a formed by the extending portion 2 b of the beam end surface 10 is provided on the outer peripheral surface of the trailing arm 1. It is formed along the longitudinal direction of the portion 10a.
The convex surface portion 12 is provided by forming a bead 13 having a V-shaped cross section on a steel plate before bending by a pressing process so as to protrude in series toward the side on which the outer peripheral surface of the trailing arm 1 is formed.

The contact surface 11 is formed by one convex surface portion sandwiching a ridge line portion (top portion) 13 a of the beads 13 forming the convex surface portion 12.
The convex surface portion 12 is formed separately along the longitudinal direction corresponding to each of the end surface portions 10 a formed by the extending portions 2 b of the beam end surface 10.

  The torsion beam 2 is welded and fixed to the trailing arm 1 at least 80% of the total length of the beam end face 10 so that the torsion beam 2 can be fixed to the trailing arm 1 with a predetermined strength. .

  Specifically, as shown in FIGS. 4A and 4C, each of the longitudinal ends of the torsion beam 2 is in contact with each of the end surface portions 10a formed by the extending portions 2b and the respective convex surface portions 12. As shown in FIGS. 4 (b) and 4 (c), the outer surfaces of the torsion beam 2 and the outer periphery of the trailing arm 1 (convex surface portion 12) along the end surface portion 10a in a state where the surfaces 11 are in surface contact with each other. A build-up 14 is formed by welding along the corner where the surface intersects, and is fixed to the outer peripheral surface of the trailing arm 1.

  For this reason, there is little possibility that a gap is formed between the beam end surface 10 (end surface portion 10a) and the trailing arm 1 in the welded portion, and the fixing strength along the welded portion between the torsion beam 2 and the trailing arm 1 varies. It is difficult to occur, and it is difficult to form a stress concentration portion.

[Second Embodiment]
FIG. 5 shows another embodiment of the present invention.
In the present embodiment, the concave surface portion 15 having the contact surface 11 that can be opposed to the end surface portion 10a formed by the extending portion 2b of the beam end surface 10 is formed on the outer peripheral surface of the trailing arm 1 of the end surface portion 10a. It is formed along the longitudinal direction.
The concave surface portion 15 is provided by pressing a bead 13 having a V-shaped cross section into a steel plate before bending so as to protrude in series toward the side on which the inner peripheral surface of the trailing arm 1 is formed.

The contact surface 11 is formed by one concave surface portion sandwiching a ridge line portion (top portion) 13 a of the beads 13 forming the concave surface portion 15.
The concave surface portion 15 is formed separately along the longitudinal direction so as to correspond to each of the end surface portions 10a formed by the extending portions 2b of the beam end surface 10.

Then, as shown in FIGS. 5A and 5C, the longitudinal end portions of the torsion beam 2 are respectively formed on the end surface portion 10a formed by the extending portion 2b and the contact surface 11 of each concave surface portion 15. 5B and 5C, the outer peripheral surface of the torsion beam 2 along the end surface portion 10a and the outer peripheral surface of the trailing arm 1 (concave surface portion 15) are brought into contact with each other. A build-up 14 is formed by welding along the intersecting corners and fixed to the outer peripheral surface of the trailing arm 1.
Other configurations are the same as those of the first embodiment.

[Other Embodiments]
1. In the vehicle suspension structure according to the present invention, the torsion beam may be intermittently welded to the outer peripheral surface of the trailing arm with the beam end surface being in surface contact with the contact surface over the entire length thereof.
2. In the vehicle suspension structure according to the present invention, the torsion beam may be welded and fixed to the outer peripheral surface of the trailing arm over the entire length of the beam end surface.
3. In the vehicle suspension structure according to the present invention, the convex surface portion 12 or the concave surface portion 15 may be formed so as to correspond to only one extended portion 2 b of the pair of extended portions 2 b in the torsion beam 2.

  The present invention includes a pair of left and right trailing arms and a torsion beam having a U-shaped or V-shaped cross-sectional shape, and the torsion beam includes beam end surfaces formed at both longitudinal ends thereof, and the longitudinal direction of the torsion beam. Each of the both end portions can be used for a vehicle suspension structure in a passenger car, a work vehicle, or the like that is welded and fixed to the outer peripheral surfaces of a pair of left and right trailing arms.

DESCRIPTION OF SYMBOLS 1 Trailing arm 2 Torsion beam 10 Beam end surface 11 Contact surface 12 Convex part 15 Concave part

Claims (1)

A pair of left and right trailing arms, and a torsion beam having a U-shaped or V-shaped cross-sectional shape arranged in an attitude of opening upward or downward between the pair of left and right trailing arms ,
In the trailing arm, at least an outer peripheral surface to which the torsion beam is fixed is formed in an arc shape along the longitudinal direction in a plan view,
The torsion beam includes beam end faces formed at both longitudinal ends thereof,
The beam end surface is formed in a shape along a cross-sectional shape of the trailing arm as viewed in the longitudinal direction of the trailing arm,
The said outer peripheral surface, a convex portion or concave portion having opposed possible contact surface with the beam end faces, in side view of the vehicle, so as to face in the longitudinal direction of the vehicle, and, in the longitudinal direction of this the beam end face Formed along
Each of the longitudinal ends of the torsion beam, the disposed between opposing convex portion or concave portion, before Symbol by surface contact with each other beam end surface and the said contact surface, the outer peripheral surface of the pair of right and left trailing arms Suspension structure for vehicles that is fixed by welding.

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