JPH0775921B2 - Axle beam structure - Google Patents

Description

The present invention mainly relates to an axle beam structure of a rear wheel suspension system for an FF vehicle.

[Conventional technology]

As shown in FIG. 8, a rear wheel suspension system in a conventional FF vehicle has an axle beam 2 extending between the left and right brake drums 4 and 4 in the vehicle width direction, the axle beam 2 and a vehicle body ( It comprises a trailing arm 6 and a shock absorber 8 with a coil spring, which are respectively mounted between (not shown).

As shown in FIG. 9, the axle beam 2 is formed in a U-shaped cross section in order to keep the torsional rigidity at an appropriate value, and further, water and dust are not accumulated in the axle beam. In order to prevent it, the opening 2A is arranged so as to face downward. Reference numeral 9 is a stabilizer for reducing rolling of the vehicle body and improving running stability.
The inside is extended in the vehicle width direction, and both ends thereof are fixed to end rear cruz (not shown) assembled to the axle beam 2.

[Problems to be Solved by the Invention]

The conventional axle beam 2 is, as shown in FIG.
Since the opening 2A is arranged downward, the axle beam side walls 2B and 2C are in a vertical state with respect to the vehicle traveling direction. Therefore, when the axle beam 2 contacts a large obstacle 11 such as a tall stone on the road while the vehicle is traveling (arrow A indicates the traveling direction of the vehicle), the horizontal collision force P with the obstacle 11 is generated. It acts on the axle beam 2 properly,
The side wall 2C of the axle beam was pushed and bent to deform the axle beam, and sometimes the stabilizer 9 as well.

Therefore, as shown in Fig. 10, the axle beam body
Axle beam main body protection member 14 having an inclined outer peripheral surface 14A facing downward of the side wall 12C and extending in the vehicle width direction is fixed to the front side wall 12C of 12 by means of fixing means such as bolt nuts, welding, and adhesion. A beam structure is possible.

This is the inclined outer peripheral surface 14 of the axle beam body protection member 14.
A is caused to act as a sled so that the axle beam can slide on an obstacle to reduce the horizontal collision force P acting on the axle beam due to contact with the obstacle.

However, in this axle beam structure, since the axle beam body protection member 14 is directly attached to the axle beam body 12, the torsional rigidity of the axle beam is increased, so that the behavior during vehicle rolling and the grounding property of wheels during rough road traveling A new problem has appeared.

Therefore, as shown in FIG. 11, an axle beam structure in which a protection member 14 is attached to the side wall 12C of the axle beam main body via a spacer 13 and the beam main body 12 and the spacer 13 are arranged at a predetermined distance is considered. This is because the torsional rigidity of the axle beam is increased by attaching the protective member 14 to the axle beam main body 12, but the protective member 14 is at a predetermined distance (thickness of the spacer 13) from the axle beam main body 12.
Only separated by the axle beam body 12 and the protective member
Since the number of joints with 14 is as small as possible, the increase in torsional rigidity of the axle beam can be kept low.

However, since the axle beam body 12, the spacer 13 and the protection member 14 are all made of a metallic material and the beam body 12 and the spacer 13 and the spacer 13 and the protection member 14 are rigidly joined, the torsional rigidity of the axle beam The increase in was inevitable.

The present invention has been made in view of the above problems, and an object thereof is to prevent deformation of the axle beam body when the axle beam collides with an obstacle by attaching a protective member to the axle beam body. Another object of the present invention is to provide an axle beam structure that can be achieved and does not affect the torsional rigidity of the axle beam.

[Means for Solving the Problems] In order to achieve the above-mentioned object, the axle beam structure according to the present invention has a front side wall of an axle beam main body whose lower end portion is open and extends in the vehicle width direction in the vehicle width direction. A protective member made of a rigid member that extends and extends in front of the axle beam main body and from above the lower end of the axle beam main body toward the lower end of the axle beam main body, and has a sloping surface that reaches a height lower than the lower end of the axle beam main body. And an elastic member that absorbs the twisting deformation generated in the axle beam body and suppresses the transmission of the twisting deformation to the protective member, and is configured to achieve the above object by this configuration. .

[Action]

Next, the operation of the present invention will be described. When the axle beam comes into contact with an obstacle on the road while the vehicle is traveling, firstly, an axle beam body protection member (hereinafter simply referred to as a protection member) attached to a front side wall of the axle beam body (hereinafter simply referred to as a beam body) is provided. The outer peripheral surface of said) contacts an obstacle. However, since the outer peripheral surface of the protective member is inclined downward toward the front side wall of the beam main body, the protective member acts as a sled, and the axle beam main body and the protective member integrally work on obstacles. You can slide over obstacles. Therefore, the collision force in the horizontal direction due to the contact with the obstacle is mitigated and the deformation of the beam body is prevented.

Further, since the elastic member is interposed between the protective member and the beam main body, the axle beam is more easily twisted as compared with the case where the beam main body and the protective member are rigidly joined, that is, the axle beam The increase in torsional rigidity is extremely small.

Next, this point will be described in more detail. Now, when attaching the protective member to the axle beam main body, it is assumed that they are joined at both ends in the longitudinal direction, and if the joined portion is joined so as to directly abut these members, the joined portion will be a rigid joint. Become. Therefore, when a torsional force is applied to the axle beam body, the protective member is also twisted with the same degree of twist angle as the axle beam body, so the axle beam with the protective member has a total of the rigidity of both members. It will have rigidity.

On the other hand, as in the present invention, when an elastic member is interposed in the connecting portion between the axle beam main body and the protective member, and a gap is provided between both members, the connecting portion becomes a flexible connection due to the elastic member, When a torsional force is applied to the axle beam body, the protective member is twisted by a smaller twist angle than the axle beam body due to the deformation of the elastic member, and due to the gap, the protective member is deformed in section even if the axle is deformed. Since it does not interfere with the beam body, the rigidity of the axle beam with the protective member is less than the sum of the rigidity of both members. Therefore, by appropriately selecting the hardness of the elastic member, it is possible to suppress the increase in rigidity so as not to substantially affect the rigidity.

〔Example〕

Next, an embodiment of the present invention will be described with reference to the drawings. 1 and 2 show a first embodiment of the present invention, and FIG. 1 shows a perspective view of a rear wheel suspension system of an FF vehicle to which an axle beam structure according to the present invention is applied. 2 shows a cross-sectional view of the axle beam structure.

As shown in FIG. 1, the rear wheel suspension system 20 has an axle beam 21 having brake drums 4, 4 attached to both ends thereof and extending in the vehicle axial direction, and one end portion attached to the axle beam 21. And a pair of trailing arms whose other end extends to the front side and is attached to the vehicle body (not shown)
6, 6 and a pair of coil spring-equipped shock absorbers 8, 8 each having one end attached to the beam 21 and the other end attached to the vehicle body.

As shown in FIG. 2, the axle beam 21 has a U-shaped cross section and is provided with a beam main body 22 with an opening facing downward so that water, dust and the like do not accumulate inside.
And a protection member 24 attached to the front side wall 22C of the beam body 22 and having a substantially V-shaped cross section.

The protection member 24 extends in the vehicle width direction, extends in front of the axle beam 21 and from above the lower end of the axle beam toward the axle beam 21, and has a sloped surface 24A having a height equal to or lower than the lower end of the axle beam. It is made of a member and is fixed to the front side wall 22C via an elastic member (rubber pad) 27. Further, the angle of the inclined surface 24A may be any angle that allows the inclined surface 24A to act as a sled even when it collides with an obstacle and get over the obstacle.

The spacer 25 is provided with a bolt 26 protruding therefrom, while the protective member 24 is provided with a rubber pad 27 having a bolt insertion hole formed therein.The bolt 26 is inserted into the bolt insertion hole, and the retainer 28 is inserted. The protective member 24 is attached to the side wall 22C by tightening the nut 29 via the. In addition,
Reference numeral 25A is a weld bead.

Next, the operation of the axle beam structure according to the present embodiment will be described below.
A description will be given with reference to FIGS.

As shown in FIG. 3 (a), when the axle beam 21 comes into contact with the obstacle 11 projecting high on the road, the inclined surface 24 A of the protection member 24 first comes into contact with the obstacle 11. Then, the axle beam 21 slides on the outer surface of the obstacle like a sled by using the inclined surface 24A of the protection member 24 as a sliding surface, and FIG.
As shown in (c), it is possible to get over the obstacle 11. That is, one upper end of the inclined surface of the protective member is positioned above the lower end of the front side wall, and the other lower end is positioned at the same height as or lower than the lower end of the front side wall so that the obstacle is slid. By the action, you can get over without damaging the axle beam. At this time, the horizontal force when the inclined surface collides with the obstacle is decomposed into the downward component force along the inclination direction and the upward component force in the direction perpendicular thereto, and the upward component force acts to lift the axle beam. None, it is able to overcome obstacles.

In this way, when the axle beam 21 comes into contact with an obstacle, the beam main body side walls 22B and 22C in a state of sliding on the obstacle and facing the obstacle have a horizontal direction as shown by reference character P in FIG. A large collision force does not act and deformation of the axle beam 21 is prevented. Further, since the large horizontal collision force P does not act on the axle beam 21, the boarding vehicle is not shocked.

While the axle beam 21 is in contact with the obstacle,
When passing over 11, the axle beam 21 will be pushed upward by the obstacle 11, but the axle beam 21
The shock absorbers 8, 8 with coil springs provided at both ends of 21 absorb the pushing amount h, and the vertical impact force caused by the axle beam 21 contacting the obstacle 11 is mitigated. It is not a big shock to the person.

Further, the protective member 24 is placed at a predetermined distance from the beam body 22 (the spacer 25
Of the protective member 24 is fixed to the beam main body 22 via the spacer 25, and a rubber pad 27 is provided between the spacer 25 and the protective member 24. Therefore, the amount of increase in the torsional rigidity of the axle beam 21 is extremely small and does not adversely affect the stability of the vehicle when rolling and the grounding property when traveling on a rough road. On the other hand, since the protective member and the axle beam main body are separate members, the moldability of the axle beam can be kept good as compared with the case where the axle beam and the protective member are integrally molded, and a protective member is required. It is possible to share the axle beam between the vehicle with the alley and the vehicle that does not require a protective member.

FIG. 4 shows a second embodiment of the present invention.

The front side wall 22C of the beam main body 22 has a protruding portion bent in a V-shaped cross section, and a protection member 3 having an outer peripheral surface 30A.
0 is attached to the beam main body 22 by bolting via spacers 27 made of rubber to spacers 25 having both ends thereof fixed to the side wall 22C on the front side by welding. Protective member 30
The lower side edge portion 31 is bent and wraps around below the front side wall 22C.

Thus, in this embodiment, the protective member that functions as a sled
28 extends to the lower side of the front side wall 22C of the beam body, so that the axle beam can reliably slide on the obstacle. Therefore, the present embodiment is more effective than the first embodiment in preventing the deformation of the axle beam.

FIG. 5 shows a third embodiment of the present invention. The difference from the second embodiment (see FIG. 4) is that the beam main body is different.
The point is that the shape of the protective member 32 attached to 22 is different. The protective member 32 is the protective member in the second embodiment.
Similar to 30, the protruding portion is formed in a V shape in cross section, and the lower side edge portion 33 passes below the beam main body 22 and the rear side wall 22.
It is located below B.

Thus, in this embodiment, the protective member 32 that functions as a sled is provided.
However, since it extends below the side wall 22B on the rear side of the beam body, the axle beam can surely slide on the obstacle. Therefore, this embodiment is more effective than the second embodiment (see FIG. 4) in preventing the deformation of the axle beam.

Further, FIG. 6 shows a fourth embodiment of the present invention. The protection member 34 wraps around the lower side of the beam main body 22 and projects to the rear side, and is curved upward, and an outer peripheral surface 34A that faces downward of the beam main body 22 is also formed on the rear side. The present embodiment is effective in preventing the deformation of the axle beam not only when the vehicle is moving forward but also when moving backward.

FIG. 7 shows a fifth embodiment of the present invention, in which the front side wall 22C of the beam main body 22 is provided with a protective member 24 through a rubber elastic body 36 at both ends thereof by a bolt 26A and a nut 29. It is fixed.

That is, by interposing the elastic body 36 between the beam main body 22 and the protection member 24, an increase in the torsional rigidity of the axle beam is suppressed. The elastic body 36 is interposed in the entire longitudinal direction of the vehicle, or the bolt 26A and the nut 2
Although it may be interposed only near the fixing portion by 9, the latter can suppress the increase amount of the torsional rigidity of the axle beam to be smaller than that of the former.

In each of the above-described embodiments, the protective member has the same thickness as the beam body, but the protective member only needs to have sufficient rigidity to act as a sled against an obstacle, The thickness is appropriately determined according to the material.

Further, the angle of the inclined surface may be any angle as long as the inclined surface acts as a sled, for example, in the embodiment shown in FIG.
The embodiment shown in Figures and 5 is about 45 °.

Furthermore, the lower end of the inclined surface is the same height as the lower end of the beam body,
It must be below it, at about the same height in FIG. 2 and below in FIGS.

〔The invention's effect〕

As is clear from the above description, according to the present invention, since the warp-shaped protection member is provided on the front side wall of the axle beam body, even if the axle beam collides with an obstacle such as rock protruding from the road surface. The protective member can prevent the axle beam body from being deformed by the collision first, and the warping action of the protective member generates an upward force from the collision force at that time, allowing the axle beam to escape upward and overrun obstacles. In addition, since the protective member is attached to the axle beam body via an elastic member that absorbs torsional deformation that occurs in the axle beam body and suppresses transmission of this torsional deformation, the torsional rigidity of the axle beam due to the attachment of the protective member Can be suppressed and the torsional rigidity thereof is not deteriorated. Therefore, when the present invention is applied to a vehicle, it is possible to remarkably improve running performance on rough roads.

On the other hand, since the protective member and the axle beam main body are separate members, the formability of the axle beam can be kept good.

[Brief description of drawings]

1 is a perspective view of a rear wheel suspension system of an FF vehicle to which the first embodiment of the present invention is applied, FIG. 2 is a sectional view taken along line II-II shown in FIG. 1, and FIG. 3 (a). (C) is explanatory drawing explaining the effect | action of the 1st Example of this invention, FIG. 4 is a principal part transverse cross section which shows the 2nd Example of this invention, FIG. 5 is the 3rd of this invention. FIG. 6 is a cross-sectional view of an essential part showing the fourth embodiment of the present invention, and FIG. 7 is a cross-sectional view of the essential part showing a fifth embodiment of the present invention. FIG. 8 is a perspective view showing a rear wheel suspension system of a conventional FF vehicle, FIG. 9 is a cross-sectional view showing a state in which a conventional axle beam contacts an obstacle, and FIGS. 10 and 11 are conventional problems. FIG. 7 is a cross-sectional view of a main part showing another embodiment of the invention proposed to solve the above problem. 6 ... Trailing arm, 8 ... Shock absorber with coil spring, 9 ... Stabilizer, 11 ... Obstacle, 21 ... Axle beam, 22 ... Axle beam body, 25 ... Spacer, 24,30,32 , 34 …… Axle beam protection member, 24A, 30A, 34A …… Inclined outer peripheral surface, 27 …… Rubber pad, 28 …… Retainer, 36 …… Elastic body.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-55-112444 (JP, A) actual open Sho-52-94638 (JP, U) actual open Sho-56-39507 (JP, U) actual open Sho-56- 44987 (JP, U) Japanese Patent Sho 57-60963 (JP, B2)

Claims (1)

[Claims] 1. A front side wall of an axle beam main body that extends in the vehicle width direction and has a lower end opened, and extends from the front side wall of the axle beam body in the vehicle width direction from above the lower end of the axle beam body. A protective member made of a rigid member extending toward the lower end of the axle beam body and having a sloped surface at a height equal to or lower than the lower end of the axle beam body is absorbed into the protective member by twisting deformation occurring in the axle beam body. The axle beam structure, wherein the axle beam structure is attached via an elastic member that suppresses transmission of the twisting deformation of the.