JPH0645361Y2 - suspension - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention relates to a suspension in which a carrier moves up and down with a rail as a guide, and the vibration of the carrier is damped by a buffer means provided on the rail.

(Prior Art) Conventionally, two ends of a moving body that supports a carrier are vertically movably engaged with two rails arranged in the vertical direction of a vehicle body,
A rail guide type suspension that damps vibrations of a carrier that moves up and down along a rail has been proposed (eg, US Pat. No. 2156580).

This is a spring for damping the vibration of the moving body while the cylindrical bodies formed at both ends of the moving body are slidably fitted into the rails so that the moving body can move up and down along the rails. Is arranged.

(Problems to be Solved by the Invention) However, since the above-mentioned conventional suspension uses the spring as the cushioning member, the space for disposing the spring is large and it is difficult to reduce the size.

(Means for Solving the Problems) In order to solve the above problems, according to the present invention, a rail disposed in a vertical direction of a vehicle body is engaged with a moving body that supports a carrier so that the mobile body can move up and down. In the suspension for damping the vibration of the vertically moving carrier, one end of the rail is fixed to the body, and the rail is fitted in the vertical direction of the vehicle body and is fitted to the outside of the torsion bar, and one end of the rail is the torsion bar. And a ball screw shaft mounted on the torsion bar so that the torsional force can be transmitted by being fixed to the free end, and a ball nut screwed to the ball screw shaft is mounted on the moving body. When the carrier moves up and down due to bouncing of the vehicle body, the ball nut moves up and down together with the carrier, It is characterized in that the screw shaft is configured to be twisted and rotated.

(Operation) As described above, according to the present invention, the rail is composed of the torsion bar and the ball screw shaft attached to the torsion bar so that the torsional force can be transmitted, and the moving body supporting the carrier is provided with the ball screw shaft. A ball nut to be screwed is attached, and when the carrier moves up and down due to bouncing of the vehicle body, the ball nut moves up and down integrally with the carrier to twist and rotate the torsion bar via the ball screw shaft. As a result, the rail itself can be provided with a cushioning function, there is no need to separately provide a spring as a cushioning member as in the conventional case, a spring mounting space is not required, and downsizing can be achieved.

(Embodiment) FIG. 1 is a front view showing the configuration of a first embodiment of the present invention, and FIG. 2 is a side view thereof. This embodiment shows an example in which the present invention is applied to a MacPherson strut suspension.

The carrier 2 coupled to the rotating shaft of the tire 8 is rotatably mounted on a rod-shaped moving body 4 arranged in the horizontal direction so as to be rotatable around its axis. Struts 3 are provided on top of the carrier 2.
The lower end of is fixed.

The two rails 1 are arranged in the vertical direction of the vehicle body,
Both ends of the moving body 1 are engaged with these rails 1 so as to be vertically movable.

The rail 1 is composed of a torsion bar 7 and a ball screw shaft 6, as shown in cross section in FIG. The lower end of the torsion bar 7 is fixed to the fixed arm 22. The fixed arm 22 is fixed to the body 20. The upper end of the torsion bar 7 is a free end.

The ball screw shaft 6 is formed in a tubular shape and is fitted on the outside of the torsion bar 7. Ball screw shaft 6
The lower end of is rotatable on the outer circumference of the torsion bar 7 via a bearing 16, and the upper end is fixed to the upper end of the torsion bar 7, and a bearing 15 is interposed on the outer circumference thereof to rotate on the support arm 21. It is supported in a simple state. The support arm 21 is fixed to the body 20.

A screw having a long lead is cut on the outer periphery of the ball screw shaft 6, and ball nuts 5 screwed onto the ball screw shaft 6 are provided at both ends of the moving body 4. The ball nut 5 is positioned so as to be located at the lower end of the ball screw shaft 6 when there is no load.

Therefore, when the carrier 2 moves up and down due to bouncing of the vehicle body, the ball nut 5 moves up and down together with the carrier 2. When the ball nut 5 moves up and down, one end of the ball screw shaft 6 is fixed to the torsion bar 7, and one end of the torsion bar 7 is fixed to the fixed arm 22. Therefore, both the ball screw shaft 6 and the torsion bar 7 are Twist. This twisting reaction force serves as a resistance force against the vertical movement of the carrier 2, that is, a buffering force. Where the spring constant is
It is determined by the torsional rigidity of the ball screw shaft 6 and the torsion bar 7, and the length of the twisted portion of the ball screw shaft 6 changes depending on the vertical position of the carrier 2. As a result, the rebound side has a small spring constant, and the bound side has a large spring constant.

The lead length of the ball screw shaft 6 is set to an appropriate length according to the magnitude of the buffering force. For example, the ball screw shaft 6 is set to rotate several tens of degrees while the ball nut 5 moves from the lower end to the upper end of the ball screw shaft 6. The screws of the two ball screw shafts 6 are cut in opposite directions.

Therefore, after mounting on the vehicle body, the ball nut 5 moves upward depending on the load and moves to a position where the load and the reaction force of the ball screw shaft 6 are balanced.

Next, FIG. 4 is a front view showing the configuration of the second embodiment of the present invention. In the figure, the same components as those in the first embodiment are designated by the same reference numerals and the description thereof will be omitted.

In this embodiment, the compliance steer in the front-back direction of the vehicle body can be absorbed. That is, in this embodiment, in addition to the configuration of the first embodiment, the connecting portion 2a of the carrier 2 is biased toward the center on the outer periphery of the moving body 2
Two springs 10 are fitted, and further, in the connecting portion 5a between the ball nut 5 and the moving body 4, a bush 9 (a pillow ball may be used) is interposed between the connecting portion 5a and the moving body 4. Characterize. The spring 10 is regulated by a stopper 11 fixed to the outer circumference of the moving body 4. The side surface of the connecting portion 5a of the ball nut 5 is shown in FIG.

With this configuration, in addition to the effects of the first embodiment, this embodiment can absorb the compliance steer in the front-rear direction of the vehicle body. That is, as shown in FIG. 6, when the brake is applied, a force that pushes the carrier 2 backward (the right direction in the figure is the front) acts. Therefore, the carrier 2 moves forward. At this time, the reaction force of the spring 10 and the bush 9 suppresses the movement of the carrier 2, and this exhibits an action of absorbing the compliance steer in the front-rear direction of the vehicle body. Similarly, the reaction force of the spring 10 and the bush 9 acts also when the carrier 2 moves forward when starting or accelerating.

Further, for example, in the case of the conventional MacPherson strut suspension, when the lower arm is short, it is not possible to give a sufficient negative camber at full bound, but by using the rail for the lower, a sufficient camber change can be given. .

Although the ball screw shaft 6 and the torsion bar 7 are both twisted in the above-mentioned embodiment, this is because the rigidity of the ball screw shaft 6 is increased so that only the torsion bar 7 is twisted substantially. good.

(Effect of the Invention) As described in detail above, according to the present invention, the rail is composed of the torsion bar and the ball screw shaft attached to the torsion bar so that the torsional force can be transmitted. Ball nuts that are screwed onto the ball screw shaft are attached to both ends of the ball nut so that when the carrier moves up and down due to bouncing of the vehicle body, the ball nut moves up and down together with the carrier to twist and rotate the torsion bar. With the above configuration, the rail itself can have a cushioning function, and there is no need to separately provide a spring as a cushioning member as in the conventional case.
A spring installation space is not required, and the size can be reduced.

[Brief description of drawings]

FIG. 1 is a front view showing the structure of the first embodiment of the present invention, and FIG.
Figure is its side view, Figure 3 is a cross-sectional view of the rail in Figure 1,
FIG. 4 is a front view showing the construction of the second embodiment of the present invention, and FIG.
FIG. 6 is a side view of the rail and the ball screw shaft in FIG. 4, and FIG. 6 is a front view showing a state when the carrier moves forward in the same embodiment. 1 ... Rail 2 ... Carrier 3 ... Strut 4 ... Moving body 5 ... Ball nut 6 ... Ball screw shaft 7 ... Torsion bar 8 ... Tire

Claims (1)

[Scope of utility model registration request] 1. A suspension in which a moving body supporting a carrier is engaged with a rail arranged in a vertical direction of a vehicle body so as to be vertically movable, and vibration of the carrier moving vertically along the rail is damped. , One end is fixed to the body, the torsion bar is arranged in the vertical direction of the vehicle body, and the torsion bar is fitted on the outside of the torsion bar, and the one end is fixed to the free end of the torsion bar so that the torsion bar is twisted. A ball screw shaft mounted so as to be able to be transmitted, and a ball nut that is screwed to the ball screw shaft is attached to the moving body, and when the carrier moves up and down due to bouncing of the vehicle body, the ball The nut moves up and down together with the carrier,
A suspension characterized in that the ball screw shaft is configured to be twisted and rotated.