JPH04151311A - Suspension device - Google Patents

Abstract

PURPOSE:To smooth the slide of a piston by canceling bending force and improve the riding comfortableness, by making the crossing angle of a fitting surface that fits a strut upper end to a car body side, and an extension line that extends a strut center axis line to a car body upper part side, slightly smaller than 90 degrees on a car body outer part side. CONSTITUTION:At an upper insulator 26, an elastic body 26c is pinched between a bottomed inner pipe 26a and a flanged outer pipe 26b, and also the bottom of the pipe 26a and the end portion of a piston rod 24 are fixed, and at the same time the flange portion of the pipe 26b is fixed at a car body. And a fixing surface between the pipe 26b and the car body is set as a fitting surface L24 whose purpose is to fit a strut upper end to the car body side. In this instance, the crossing angle theta21 of the fixing surface L24 and an extension line 23' that extends a strut center axis line L23 to a car body upper part side, is set slightly smaller (preferably smaller by about 1 degree - 5 degrees) than 90 degrees on a car body outer part side. As a result, force opposite to bending force is generated at the car body side fitting surface L24. Zero is realized by canceling the bending force by means of the opposite force.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a suspension device for a vehicle, and particularly to a strut type suspension device.

(Prior art) The strut in a strut-type suspension device plays the role of suspending the wheel from the vehicle body and buffering the vertical movement of the wheel, and exerts a damping force by connecting the vehicle body side member and the wheel side member. It consists of a shock absorber whose overall length can be changed at the same time, and a coil spring inserted in parallel with the shock absorber.

Ideally, the connection point between the strut and the wheel is the intersection of the line connecting the tire grounding point and the wheel center with the axis of the suspension link (more precisely, the intersection between the perpendicular line passing through the tire grounding point and the suspension link It is desirable to set it at a position where the intersection point with the axis coincides with the above-mentioned point (for convenience, since the difference is small). However, this suitable position is obstructed by the road wheel, so in reality,
It is set slightly shifted toward the inside of the vehicle body from the above-mentioned intersection.

For this reason, when the wheel moves up and down, a force that tends to bend the strut (hereinafter referred to as bending force) is generated, which impedes the sliding of the piston of the shock absorber and deteriorates ride comfort.

Therefore, a so-called "offset coil spring" suspension device is known in which only the center axis of the coil spring is mounted offset from the center axis of the strut to the outside of the vehicle body.

FIG. 7 is a schematic configuration diagram of the same, in which 10 is a wheel, 11 is a suspension link, 12 is a strut, 13 is a coil spring, Pl+ is a link pivot point on the vehicle body side, P,
□ is the link pivot point on the axle side, P13 is the wheel center, PI4 is the grounding point of the wheel (tire), PI5 is the mounting point on the vehicle body side at the upper end of the strut, PI6 is the intersection of the strut axis and the tire rotation axis at the lower end of the strut, PI7 is the Line L1 connecting wheel grounding point P14 and wheel center P13
1 and the axis of the link 11, Ll+ is the center axis of the strut, L12 is a line indicating the strut upper insulator mounting surface for attaching the upper end of the strut to the vehicle body, LIS is a line parallel to L14, θ1. is L1
3 and L12 (90 degrees).

In such a configuration, when a force F from the road surface acts on the wheel 10, that force F is applied to the intersection point PI7, and the strut 12 is bent inward as a component of the force F' applied to the coil spring axis L1□. A force FY is generated to bend the strut 12 inward, and sliding resistance of the piston remains (a problem to be solved by the invention). Force F
Since Y remains, there is a problem that needs to be solved in terms of further improving ride comfort.

The present invention was made by focusing on these problems.
The challenge is to sufficiently reduce the bending force acting on the struts to further improve ride comfort.

(Means for Solving the Problems) In order to achieve the above-mentioned problems, the present invention sets the intersection angle between the mounting surface for attaching the upper end of the strut to the vehicle body side and an extension line extending the strut center axis upwardly to the vehicle body side. It is characterized by being slightly smaller than 90 degrees on the outer side.

(Function) In the present invention, bending force (F7
) and a force (-FY) in the opposite direction is generated, and these pair of forces act as a couple.

Therefore, the bending force F is canceled out by the car FY, and the sliding resistance of the piston is significantly reduced, resulting in further improvement in ride comfort.

(Example) Hereinafter, the present invention will be explained based on the drawings.

1 to 6 are diagrams showing an embodiment of a suspension device according to the present invention, and are examples in which the suspension device is applied to an offset coil spring suspension device.

In Fig. 1, 20 is the wheel, 21 is the link, 22 is the strut, 23 is the coil spring, PZI is the link pivot point on the vehicle body side, P2□ is the link pivot point on the axle side, PX3 is the wheel center, and PX3 is the wheel center point. The grounding point, Pus, is the mounting point on the vehicle body side at the upper end of the strut, ptb is the intersection of the strut axis and the tire rotation axis, and pzt is the line LZ+ connecting the wheel grounding point PZ4 and the wheel center P23.
and the axis of link 21, L23 is the center axis of the strut, L24 is a line indicating the strut upper insulator mounting surface for attaching the upper end of the strut to the vehicle body, and θ2I is an extension line of Lt4 and L23 on the upper side of the vehicle body. L
2.゛ is the intersection angle on the outside of the vehicle body.

FIG. 2 is a detailed view of section A in FIG. 1. In this diagram,
24 is a piston rod of the shock absorber, 25 is a member for the upper end side support of the coil spring 23, 26 is an upper insulator, and the absorber insulator 26 has an elastic force between the bottomed inner cylinder 26a and the flanged outer cylinder 26b. body 26
c between the bottom of the bottomed inner cylinder 26a and the piston rod 2.
At the same time, the flange of the flanged outer cylinder 26b is fixed to the vehicle body.

Here, the fixing surface between the flanged outer cylinder 26b and the vehicle body is a mounting surface L for attaching the upper end of the strut 22 to the vehicle body side.
24, and in this embodiment, this fixed surface (L2.) and
The intersection angle (θ2.) between the strut center axis L'XLz:+ and the extension line (L23") extending upwards of the vehicle body is slightly smaller than 90 degrees (preferably 1 degree to 5 degrees) on the outside of the vehicle body. to a lesser extent).

FIG. 3.4 is a diagram showing changes in the state of the upper insulator 26 as the suspension device is assembled. That is, the upper insulator 26 exhibits two states: a free state (FIG. 4) in which it is attached alone to the vehicle body, and a deformed state (FIG. 5) in which a strut is assembled. 1st
．． The upper insulator 26 in FIG. 2 is in the latter deformed state.

In such a configuration, when a force F from the road surface acts on the wheel 20, this force F is applied to the center axis L of the coil spring 23.
It acts along 2□ and touches the intersection P27,
A force that tries to bend the strut 22 inward (bending force F,
) occurs.

In this embodiment, as shown in FIG. 5, a curve F7 in the opposite direction to the bending force F is generated on the vehicle body side mounting surface (L24) of the upper insulator 26.

Here, FY and -FY are a pair of forces that act on one line of action, have the same magnitude, and have opposite directions. Therefore, the bending force F7 can be canceled out to zero by the car F7, and the piston of the shock absorber can slide smoothly, thereby further improving the riding comfort.

In addition, in the above embodiment, an example of application to an offset coil spring suspension device was shown, but the present invention is not limited to this, and may be applied to a normal suspension device.

FIG. 6 is a diagram showing another embodiment, which is an example of application to a normal suspension device that does not use an offset coil spring. Note that the same components as in the above embodiment are given the same reference numerals.

In this figure, the difference from the previous embodiment is that the center axis L30 of the coil spring 30 and the center axis L21 of the strut 22 are coaxial.

In such a configuration, a bending force FY' that is slightly larger than the bending force FY of the above embodiment is generated, but the bending force FY' generated on the vehicle body side mounting surface (LZ4) of the amber insulator 26 and the bending force F7'' are is in a "couple" relationship as in the previous example, so the bending force FYI is
It can be canceled without any problem by YI.

(Effects) According to the present invention, it is possible to generate a force that is equal to and in the opposite direction to the bending force acting on the strut, that is, a force couple.

Therefore, the bending force can be canceled out to make the piston slide smoothly, and the riding comfort can be further improved.

[Brief explanation of the drawing]

1 to 5 are diagrams showing one embodiment of the suspension device according to the present invention, in which FIG. 1 is a schematic configuration diagram thereof, FIG. 2 is a configuration diagram of its main parts, and FIG. FIG. 4 is a state diagram of the upper insulator in its deformed state, FIG. 5 is a diagram of its couple action, FIG. 6 is a schematic configuration diagram showing another embodiment of the suspension device according to the present invention, and FIG. 1 is a schematic configuration diagram showing a conventional example. 22... Strut, L23... Central axis of strut, L23'
・・・・・・Extension line on the upper side of the vehicle body, L12・・・・Line indicating the mounting surface, θ2, ・・・・Intersection angle.

Claims (1)

[Claims] The intersection angle between the mounting surface where the upper end of the strut is attached to the vehicle body and the extension line extending the center axis of the strut upward to the vehicle body is
A suspension device characterized in that the angle is slightly smaller than 90 degrees on the outer side of the vehicle body.