JP2007307966A - Suspension device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a suspension device improved in degree of freedom in lay-out and capable of forming a locus rising in rear when riding over a projection without using an actuator such as a cylinder device. <P>SOLUTION: The suspension device is provided with a trailing arm 3, to which an axle 2 rotatably supporting a wheel 1 is fixed and which is extended forward in the back and forth direction of a vehicle, and a rubber bush 4 connecting a front end of the trailing arm 3 to a car body side member freely to swing in the vertical direction. The trailing arm 3 is provided with a first arm member 7 and a second arm member 8 so as to be telescoped in the extending direction. A projection part 12 and a guide groove 12 are provided to telescope the trailing arm 3 in response to displacement of the wheel 1 in the vertical direction. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a vehicle suspension apparatus including a trailing arm.

In a trailing arm suspension system with a trailing arm, as a method of improving the ride comfort by mitigating the impact generated when riding over a protrusion, the wheel center trajectory is a rear-up trajectory (the vehicle longitudinal direction as it is displaced upward) There is a method of making the trajectory displaced backward).
As a simple method for making the trajectory after this rise, there is a method of setting the mounting point of the trailing arm on the vehicle body side to a position higher than the wheel center. However, in this method, the vehicle body floor becomes a low floor vehicle. There is a problem that the mounting point of the trailing arm on the vehicle body side cannot be easily set high.

As conventional techniques for this, for example, there are techniques described in Patent Documents 1 and 2. In these conventional technologies, the suspension member, which is a vehicle body side member that supports the front end portion of the trailing arm, is displaced up and down by an actuator, or the vehicle body side mounting portion of the trailing arm is displaced by an actuator, thereby I try to get a backtrack.
JP 2005-53462 A JP-A-10-217735

However, in the above prior art, since it is necessary to use an actuator, it is necessary to secure a space for arranging an actuator main body composed of a hydraulic cylinder device or the like and to secure a driving power source.
The present invention has been made by paying attention to the above points, and provides a suspension device that has a high degree of freedom in layout and can be traced backward when overhanging a protrusion without using an actuator such as a cylinder device. Is an issue.

In order to solve the above-described problems, the present invention provides a rotation support member that rotatably supports a wheel, a trailing arm that is fixed to the rotation support member and extends forward in the vehicle front-rear direction, and the trailing arm. In a suspension device comprising a vehicle body coupling member that couples a trailing arm front end and a vehicle body side member so as to be swingable in a vertical direction,
The trailing arm is configured to be extendable / contractible in the extending direction, and further includes expansion / contraction means for extending / contracting the trailing arm according to the displacement of the wheel in the vertical direction.

  According to the present invention, it is possible to secure a rearward trajectory of the wheel center by extending and retracting the trailing arm by the expansion / contraction means in accordance with the vertical displacement of the wheel.

Next, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a schematic configuration diagram showing an example of the suspension device of the present embodiment.
(Constitution)
First, the structure will be described. As shown in FIG. 1, an axle 2 that rotatably supports the wheel 1 is fixed to a rear end portion of the trailing arm 3. The trailing arm 3 extends in the vehicle front-rear direction, and a front end portion of the trailing arm 3 is connected to a vehicle body side member via a rubber bush 4 so as to be swingable up and down. Reference numeral 5 denotes a torsion beam that connects the left and right trailing arms 3.

  The trailing arm 3 of the present embodiment is separated into a first arm member 7 and a second arm member 8 at a position 6 in FIG. As shown in FIG. 2, in the trailing arm 3 of this embodiment, the first arm member 7 connected to the rubber bush 4 and the second arm member 8 that fixes the axle 2 extend in the extending direction (first The two arm members are connected so as to be relatively movable in the axial direction of the tip portion. The connecting structure will be described with reference to FIG. 2. A bottomed hole 8 a extending in the extending direction is opened at the tip of the second arm member 8. The first arm member 7 is coaxially inserted into the bottomed hole 8a. The first arm member 7 is supported by the second arm member 8 so as to be movable only along the axial direction of the bottomed hole 8a via a slide member 11 such as a direct acting slide bush. Thereby, the length of the trailing arm 3 can be expanded and contracted. The hole 8a formed at the tip of the second arm member 8 does not have to be bottomed.

Here, the portion of the first arm member 7 guided by the slide member 11 is formed to have a relatively small diameter, and the rear end portion of the first arm member 7 is guided by the slide member 11. As a result of the large-diameter portion having a diameter larger than that of the portion and 7a, the first arm member 7 is prevented from coming off from the bottomed hole 8a of the second arm member 8 and coming off.
Further, as shown in FIG. 3, the protrusions 12 project in the vehicle width direction from the left and right sides of the second arm member 8. The protrusion 12 constitutes a guided portion.

  The rubber bush 4 fixed to the front end portion of the first arm member 7 is configured such that an elastic body 4c is interposed between an inner cylinder 4b and an outer cylinder 4a arranged coaxially, and the outer cylinder 4a. Is fixed to the first arm member 7 and a bolt penetrating the inner cylinder 4b is fixed to a bracket 17 supported by the vehicle body side member. Although FIG. 1 illustrates the case where the shaft of the rubber bush 4 is arranged slightly inclined with respect to the vehicle width direction, the present invention is not limited to this.

The bracket 17 is formed in a U-shape from left and right vertical plates 17a located on both sides in the vehicle width direction with the rubber bush 4 interposed therebetween, and a top plate 17b connecting the left and right vertical plates 17a. It is fixed to the vehicle body side member with a bolt 14. Since the bracket 17 of the present embodiment also supports the second arm member 8, the vibration isolating rubber 15 is inserted between the top plate 17b and the vehicle body side member, and the vibration of the bracket 17 is transmitted to the vehicle body side. That has been reduced.
And the support bolt which penetrates the said inner cylinder 4b is supported by the said right-and-left vertical board 17a. Reference numeral 16 in FIG. 4 denotes a nut that is screwed onto the tip of the support bolt.

In addition, the left and right vertical plates 17a are formed with guide grooves 1213 that are inclined in an oblique direction toward the rear in the vehicle front-rear direction as they go upward, at positions facing the protrusions 12 constituting the guided portion. . The protrusion 12 is inserted into the guide groove 12, and the protrusion 12 is restricted so as to be movable only along the guide groove 12. The present embodiment is an example where the guide groove 12 is formed by a slit. Note that the tip of the protrusion 12 protrudes from the guide groove 12, and a disk having a larger diameter than the protrusion 12 is fixed to the tip of the protrusion 12, so that the protrusion from the guide groove 12. 12 is prevented from coming off.
Further, the guide groove 12 does not need to extend linearly, and may be extended entirely or partially in a curved shape.

(Function and effect)
When the vehicle travels forward on a flat road surface, the protrusion 12 is positioned at the substantially central portion in the vertical direction of the guide groove 12 as shown in FIG.
From this state, when the wheel 1 travels upward as it passes over the protrusion, the trailing arm 3 is also displaced upward with the rubber bush 4 as the center of oscillation. Then, as shown in FIG. 5B, the protrusion 12 is also guided by the guide groove 12 and displaced obliquely rearward as it is displaced upward. That is, the second arm member 8 and the first arm member 7 swing upward while being displaced in a direction in which the overlap is reduced. As a result, the length of the trailing arm 3 becomes longer as the wheel 1 is displaced upward, and the locus of the wheel center over the protrusion is adjacent to the rearward locus. As a result, the input to the tire is reduced, the impact given to the occupant is mitigated, and the riding comfort can be improved.

When the wheel 1 is displaced downward, for example, when the wheel enters a groove or the like formed on the road surface, as shown in FIG. As a result, the second arm member 8 and the first arm member 7 are swung downward while the overlap between the second arm member 8 and the first arm member 7 is relatively increased. This shortens the length of the trailing arm 3 as the wheel 1 is displaced downward.
Here, in the above-described embodiment, the guide portion is formed by the slit-shaped guide groove 12. However, the guide portion may be formed from a recess extending along the track and the protrusion 12 may be inserted into the recess. good.
Moreover, in this embodiment, layout property is good by comprising a guide part in the bracket which supports the rubber bush 4. FIG.

  Further, as shown in FIG. 6, rubber 14 may be attached along the inner surface of the guide hole. When the rubber 14 is attached, the rubber 14 absorbs an impact generated between the guide groove 12 and the protrusion. In FIG. 6, the shape of the portion of the protrusion 12 that is inserted into the guide groove 12 is an elliptical shape along the guide groove 12, and the contact area with the guide groove 12 is increased.

In addition, you may make it the movement along the guide groove 12 of the projection part 12 smoother by mixing a solid lubricant into the rubber. The rubber may be provided on the outer peripheral side of the protrusion 12. Alternatively, as shown in FIG. 7, a metal fitting 20 may be attached to the surface of the rubber 14 to ensure sliding.
Further, as shown in FIG. 8, in the normal state, the height of the center of swinging of the trailing arm 3 in the vertical direction (the central axis of the rubber bush 4) and the protrusion 12 may be different.

1 is a schematic configuration diagram showing a suspension device according to an embodiment of the present invention. It is a side view which shows the expansion-contraction mechanism of the trailing arm which concerns on embodiment based on this invention. It is a side view which shows the position of the projection part which concerns on embodiment based on this invention. It is a side view which shows the vehicle body side attachment structure of the trailing arm which concerns on embodiment based on this invention. It is a side view which shows the behavior of the trailing arm which concerns on embodiment based on this invention. It is a figure which shows the modification of a guide groove, (a) is a side view, (b) is the AA 'sectional drawing. It is a figure which shows another modification of a guide groove, (a) is a side view, (b) is the AA 'sectional drawing. It is a side view which shows the example in the case of making the vehicle body side attachment point of a trailing arm and the height of a projection part different.

Explanation of symbols

1 Wheel 2 Axle (Rotating support member)
3 Trailing Arm 4 Rubber Bush 7 First Arm Member 8 Second Arm Member 8a Bottomed Hole 10 Car Body Side Member 12 Projection (Guide)
13 Guide groove 17 Bracket 17a Vertical plate

Claims (6)

A rotation support member that rotatably supports the wheel, a trailing arm that is fixed to the rotation support member and extends forward in the vehicle front-rear direction, and a trailing arm front end that can swing the trailing arm up and down And a vehicle body connecting member that connects the vehicle body side member,
While making the trailing arm extendable in the extending direction,
A suspension apparatus comprising: an extension / contraction means for extending / contracting the trailing arm according to a vertical displacement of a wheel. The trailing arm includes a first arm member coupled to the vehicle body coupling member, a second arm member to which the rotation support member is fixed, and the second arm member can be relatively displaced in the extending direction with respect to the first arm member. And a slide member connected to
The expansion / contraction means includes a guided portion provided on the second arm member, and a guide member that regulates the guided portion so as to be movable only along a guide path that extends rearward in the vehicle front-rear direction as it goes upward. The suspension device according to claim 1.   The suspension device according to claim 2, wherein an elastic body is attached to at least one of the sliding contact portions between the guide path and the guided portion. The vehicle body connecting member is a rubber bushing in which an elastic body is interposed between the inner cylinder and the outer cylinder. The outer cylinder is fixed to the trailing arm, and the inner cylinder is mounted on the vehicle body side via the bracket. It is configured to connect to the member,
4. The suspension device according to claim 2, wherein the guide path of the guide member is formed in the bracket.   The suspension device according to claim 4, wherein the bracket is connected to a vehicle body side member via an elastic body. A rotation support member that rotatably supports the wheel, a trailing arm that is fixed to the rotation support member and extends forward in the vehicle front-rear direction, and a trailing arm front end that can swing the trailing arm up and down And a vehicle body connecting member that connects the vehicle body side member,
A suspension device that displaces a wheel in a longitudinal direction of a vehicle by extending and contracting a trailing arm.

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