JP2000326714A - Toe correcting suspension bush - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve durability of a bush by arranging the elastic material bush between an inner cylinder supported by a car body and an outer cylinder fixed thereto a suspension are, and arranging the inner cylinder so as to be freely rotatable to the support shaft. SOLUTION: In a rear suspension, an elastic body bush 3 is fixed to the front end of a trailing arm 1, and theses are joined to a car body via a bracket 5. The bracket 5 is formed in an almost U shape, an outside plate 13 is installed on the car body lateral side of an upper plate, an inside plate 14 is installed on the car body central side of the upper plate, respectively, and the upper plate is fixed to a cross member. In this case, an inner cylinder 24 of the elastic body bush 3 is formed in the shape of opening a through hole 25 by obliquely cutting a steel solid material of a cross-sectional cylindrical shape, and the inclining direction is set so that the toe correcting action can be obtained, that is, so that an outer cylinder 21 is displaced forward via a bush 17 when the inner cylinder 24 is pushed to the car body lateral side.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION A rear suspension arm typified by a trailing arm has a front end connected to a vehicle body by an elastic bush. It is known that, when a vehicle turns, the rear wheels on the outside of the turn are displaced toward the oversteer side, and this is corrected to perform toecorrection toward the understeer side. The present invention belongs to the technical field of such a collect.

[0002]

2. Description of the Related Art The prior art will be described with reference to FIGS. FIG. 3 is a simplified plan view of the rear suspension, in which elastic bushes 3, 4 are fixed to the front ends of the trailing arms 1, 2, which are connected to the vehicle body via brackets 5, 6. There are various types of trailing arms. Here, the case where the two trailing arms 1 and 2 are connected by the torsion beam 7 is shown. Tires 8 and 9 are supported on the trailing arms 1 and 2, respectively. In FIG. 3, a circular portion indicated by a two-dot chain line indicates that a suspension spring and a shock absorber are arranged.

FIG. 4 is a view taken in the direction of arrow (4) in FIG. 3, in which a cross member 11 is welded to a floor panel 10 and a bracket 5 is fixed thereto by welding or the like. The bracket 5 has a substantially U-shape that is open downward, an outer plate 13 is installed on the side of the upper plate 12 on the vehicle body side, and an inner plate 14 is installed on the center side of the upper plate 12 on the vehicle body. The upper plate 12 is firmly fixed to the cross member 11 by welding or the like.

In the description of the prior art and the following description of the present invention, it is assumed that the vehicle is turning to the left as indicated by the arrow 15 in FIG. 3, and unless otherwise specified, the suspension arm is The phenomenon of the right trailing arm 1 will be described. When turning in the direction of FIG. 3, a cornering force is generated in the tires 8 and 9 in the direction of arrow 16, and this deforms the elastic bushes 3 and 4, so that the tire 8 is towed out.
The tire 9 may be displaced to the toe-in side and become so-called oversteer, which may reduce running stability during turning.

As means for solving the above problems,
The structure as shown in FIG. 5 is employed. To explain this, the inner tube 18 is sandwiched between the outer plate 13 and the inner plate 14, and the bolt 19 is passed through the outer plate 13, the inner tube 18, and the inner plate 14, and is tightly fastened with the nut 20. , The inner cylinder 18 is fixed to the vehicle body. The trailing arm 1 is welded to the outer cylinder 21, and a rubber material forming the bush 17 is integrated with the inner cylinder 18 and the outer cylinder 21 by vulcanization bonding.
A bulged portion 22 bulging forward is formed on the center side of the vehicle body of the outer cylinder 21, and a push plate 23, which is also bulged round, is welded to the inner cylinder 18 at a position corresponding thereto. The bulging portion 22 and the pressing plate 23 are formed by press-forming a steel plate, and have tapered members arranged inside and outside. A rubber material is disposed between the bulging portion 22 and the pressing plate 23 as shown in the figure.

With the above structure, when the cornering force 16 acts, the bulging portion 22 relatively moves to the side of the vehicle body (upward in FIG. 5). ). Therefore, the axis of the outer cylinder 21 is displaced forward of the axis of the inner cylinder 18, and the tire 8 on the outside of the turn is toe-collected on the toe-in side. At this time, for the tire 9 inside the turning, the bulging portion 22 of the elastic bush 4 and the pressing plate 2
3, the outer tire 8 is displaced to the toe-out side in conjunction with the displacement of the outer tire 8 to the toe-in side, and the understeer characteristic is obtained as a whole.

Further, as another solution, a structure as shown in FIG. 6 is known. In the same figure, those which have the same functions as the members described in FIGS.
The same reference numerals are given in FIG. 6 and detailed description is omitted.
6, the width direction of the vehicle body is indicated by a direction line C1-C1, and the axis of the inner cylinder 18, that is, the axis of the bolt 19 is inclined in the front-rear direction of the vehicle body as is apparent from FIG. The inclination direction is set so that when the inner cylinder 18 is displaced to the side of the vehicle body, the outer cylinder 21 is displaced forward via the bush 17.

With the above structure, when the cornering force 16 acts, the inner cylinder 18 relatively moves along its axis, and its displacement is changed via the bush 17 to the outer cylinder 21.
As a result, the tire 8 is turned to the toe-in side. The tire 9 on the opposite side is turned to the toe-out side by the opposite behavior. The principle similar to that of FIGS. 5 and 6 is disclosed in Japanese Patent Application Laid-Open No. 8-177917.

[0009]

With the structure as shown in FIG. 5, a special welding process is required for the assembling process, which is disadvantageous in cost. Further, the volume of the elastic body is reduced, which is disadvantageous in strength and durability. In particular, it is difficult to set the thickness of the elastic body indicated by the symbol L in FIG. 5 to an appropriate value. The reason for this is that if L is large, the amount of elastic deformation becomes large, so that sufficient toe-collection cannot be obtained, and furthermore, if L is small, vibration noise transmitted to the vehicle body increases. In addition, the spring constant in the torsional direction increases, and the ride quality deteriorates. Furthermore, it is good that the toe-collecting action is performed as intended, but as the swing angle of the trailing arm increases, compressive deformation is forced on the bush. Therefore, there is a need for further improvement in terms of durability, since the structure becomes complicated as if composited with compression.

Also in the structure of FIG. 6, when the trailing arm swings up and down, the bolt 19 exhibits a relative behavior such as "striking motion". The relative "sway" of
And undergoes complex deformation with compression. Such a deformation is the same as that in FIG. 5 and also has a problem in durability, and the riding comfort is deteriorated.

[0011]

SUMMARY OF THE INVENTION The present invention was conceived to solve the above-mentioned problems. An elastic bush is mainly provided with a function of only to collect, and a trailing arm is provided. In the vertical swing, the basic idea is to prevent the bush from being deformed.

According to a first aspect of the present invention, a bush made of an elastic material is disposed between an inner cylinder supported on a vehicle body using a support shaft and an outer cylinder to which a suspension arm is fixed,
The axis of the inner cylinder is inclined forward and backward with respect to the width direction of the vehicle body, thereby causing the rear tire on the outside of the turn to change in toe-in. It is characterized by being configured to be rotatable. Therefore, when the cornering force acts, the toe-collect is performed by the same phenomenon as in the case of FIG. 6, and in the vertical swing of the trailing arm, the entire elastic bush freely rotates with respect to the support shaft.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail with reference to the illustrated embodiments. In addition, about what fulfills the same function as the member explained in the prior art,
The same reference numerals are given in the drawings, and detailed description is omitted. The outer plate 13 and the inner plate 14 are made of a steel plate.
The elastic bush 3 is disposed between the elastic bush 3 and the elastic bush 3. The member indicated by reference numeral 24 corresponds to the above-described inner cylinder 18. In the case of FIG. 1, a solid material made of steel having a circular cross section is cut obliquely to form a through hole 25. . This through hole 2
The axis 5 is coaxial with the above-described direction line C1-C1, and the axis C2-C2 of the inner cylinder 25 is inclined with respect to the direction line C1-C1 by an angle θ in the front-rear direction of the vehicle body. The inclination direction is such that a toe-collecting action to be described later is obtained, that is, when the inner cylinder 24 is pushed to the side of the vehicle body (to the right in FIG. 1), the outer cylinder 21 is displaced forward via the bush 17. Is set to

On the other hand, a bolt 19 serving as a support shaft is fitted in a sleeve 26, and the sleeve 26 and the through hole 25 are inserted.
The inner metal 24 can be freely rotated with respect to the support shaft 19 by doing so. Reference numeral 28 denotes a thrust washer.

FIG. 2 is another structural example for obtaining the above-mentioned free rotation. This is because the use of the above-mentioned metal is stopped and the sleeve 26 and the through hole 25 are in direct contact with each other, and the degree of fitting at this portion is such that it can be smoothly rotated.

The operation of the above embodiment will be described. When the cornering force acts in the direction of arrow 16 during cornering, the inner cylinder 24 is pushed rightward, and the displacement is transmitted to the outer cylinder 21 via the bush 17 and the outer cylinder is displaced forward of the vehicle body. , To collect. When the trailing arm 1 swings up or down while traveling straight or turning, the inner cylinder 24 freely rotates with respect to the support shaft 19, and the deformation of the bush 17 due to this swing does not occur, or it is assumed that the bush 17 is deformed. It does not matter.

In connection with the above description, the above-mentioned problem can be solved by the following method. That is, the configuration is such that the angle θ is not set in FIG. 5 and the elastic bush 3 can freely rotate with respect to the bolt 19. by this,
The rubber material between the bulging portion 22 and the pressing plate 23 and the
The function of only the toe-collect is performed, and the bush 17 is not deformed at the time of the bump rebound.
Therefore, the above-mentioned problem can be avoided. Further, although not shown, the bulging portion 22 and the pressing plate 23 are different from those shown in FIG.
Is removed, and the control piece having the inclined surface is fixed to the inner cylinder 18 so as to be embedded in the bush 17, and the above-described free rotation structure is employed. By doing this,
It is possible to separate the phenomenon of the to collect action from the phenomenon at the time of bump rebound.

[0018]

According to the present invention, the axis of the inner cylinder is inclined forward and backward with respect to the width direction of the vehicle body, thereby causing a toe-in change in the rear tire on the outer side of the turn, and Since the bush can rotate freely with respect to the support shaft, the bush faithfully performs the torrent action on the cornering force during turning, and does not deform the bush against the vertical swing of the suspension arm. It does not occur. Therefore, since the bush is not subjected to a complicated force as in the prior art, the durability of the bush is significantly prolonged, and at the same time, the riding comfort and the steering stability are improved. Further, since the elastic bush is not intentionally given the function as the suspension spring, the characteristics of the suspension spring and the shock absorber can be exhibited as expected.

According to the present invention, the rubber material is not locally deformed as shown in FIG. 5, and the bush can be installed with a sufficient volume between the outer cylinder and the inner cylinder. Thus, it is possible to easily find a balance between the to collect action and the vibration noise reduction.

[Brief description of the drawings]

FIG. 1 is a cross-sectional plan view showing an embodiment of the present invention.

FIG. 2 is a partial cross-sectional plan view of another embodiment.

FIG. 3 is a simplified plan view of a rear suspension.

FIG. 4 is a view taken in the direction of the arrow (4) in FIG. 3;

FIG. 5 is a sectional view taken along line (5)-(5) of FIG. 4;

FIG. 6 is a sectional view similar to FIG. 5, showing another conventional technique.

[Explanation of symbols]

 12, 13, 14 Body 19 Support shaft 18 Inner cylinder 1, 2 Suspension arm 21 Outer cylinder 17 Bush C2-C2 Axis line of inner cylinder C1-C1 Direction line in vehicle width direction 8, 9 Tire 24 Inner cylinder

Claims (1)

[Claims] 1. A bush made of an elastic material is disposed between an inner cylinder supported by a vehicle body using a support shaft and an outer cylinder to which a suspension arm is fixed, and the axis of the inner cylinder extends in the width direction of the vehicle body. The inner cylinder is configured to be freely rotatable with respect to its support shaft in a type in which a toe-in change is generated in the rear tire on the outer side of the turning by the front and rear sides. A torrent-type suspension bush characterized by the following.