JPH0338003Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field The present invention relates to a device for damping the flutter of a steering wheel of an automobile.

BACKGROUND ART In such conventional damping devices, it is common to make it difficult to transmit suspension vibrations caused by tire imbalance to the steering wheel by reducing the stiffness of the steering system. Furthermore, a damping device is known in which a damper is provided between the gearbox housing and the rack bar to suppress the vibration of the rack bar in the left-right direction of the vehicle, but the vibration in the left-right direction of the rack bar is minute and the damping of flutter is insufficient. It is becoming insufficient. This is because the damper operates slowly based on the minute displacement of the rack bar, and this hardly provides any damping function.

DISCLOSURE OF THE INVENTION It is an object of the present invention to provide a steering flutter damping device that can adequately damp flutter in a manner different from the prior art.

To achieve this objective, the steering flutter damping device of the present invention is constructed as follows.

In other words, by operating the steering wheel,
In a configuration in which the tire is rotated around the axis of the lower suspension arm along with a kingpin shaft, one end is fixed to the kingpin shaft, and the other free end extends diagonally toward the tire. an arm, and a damper coupled to the free end of the arm and the body of the vehicle so as to damp vibrations relative thereto, and arranged at a predetermined inclination with respect to the lower suspension arm. We are prepared.

According to the present inventor's analysis of the suspension vibration mode when flutter occurs, the spindle hardly rotates around the kingpin axis and mainly performs swinging motion around the body attachment point of the lower suspension arm. The vibration of the vehicle's longitudinal suspension in the vicinity of the kingpin axis is approximately five times as large as the vibration of the tie rod in the left-right direction.

Therefore, flutter can be appropriately reduced by attenuating vibrations in the vehicle longitudinal direction of the suspension, which is the main cause of flutter, and this has been confirmed through experiments.

Effects of the invention As described above, the present invention substantially extends the distance from the attachment point of the lower suspension arm to the body to the connection point of the arm fixed to the kingpin shaft and the damper, and also enables the damper to be attached to the lower suspension arm. Since the damper is arranged at a predetermined inclination with respect to the kingpin arm, the arm and damper are coupled by the combined force of the longitudinal vibration between the kingpin shaft and the body and the vibration around the axis of the kingpin shaft. Displace the point by a large amount. This large displacement of the coupling point increases the operating speed of the damper and enhances the damping function, thereby effectively suppressing steering flutter.

Example The present invention will be described with reference to the embodiments shown in the drawings.

In FIG. 1, rotation of the steering wheel 10 is transmitted to the tires 24 via the steering shaft 12, pinion 14, rack 16, tie rod 18, knuckle arm 20, and spindle 22. Lower suspension arm 2
6 is rotatably supported by the body in a vertical plane at one end 28, and the spindle 22 is attached to the other end via a king pin shaft 30. The strut bar 32 extends diagonally with respect to the longitudinal direction of the automobile, and is fixed to the lower suspension arm 26 at one end, and fixed to the body 34 via a bushing 36 at the other end. An arm 38 is fixed to the kingpin shaft 30 and extends toward the tire 24. The damper 40 is
It extends diagonally with respect to the longitudinal direction of the automobile, and is attached to the body 34 and the arm 38 through ball joints 42 and 44 at both ends, respectively.

FIG. 2 shows the vibration mode of the suspension when flutter occurs when the damper 40 is not installed. When flutter occurs, the spindle 22
hardly rotates around the king pin shaft 30, but swings almost integrally with the lower suspension arm 26 around the body attachment point of the lower suspension arm 26, which prevents vibration of the tie rod 18 in the left-right direction of the vehicle. It can be seen that the vibration of the suspension in the longitudinal direction of the vehicle is much larger than that of the previous model.

In the device shown in FIG.
In other words, since vibrations, which are the main cause of flutter, are attenuated, flutter can be reduced.

FIG. 3 is an experimental graph in which the actual damping effect of flutter by the apparatus shown in FIG. 1 was investigated. It can be seen that the maximum value of the rotational acceleration of the steering wheel is lower when the damper 40 is present (solid line) than when the damper 40 is not present, and a sufficient effect is exhibited in damping flutter.

[Brief explanation of the drawing]

Fig. 1 is a block diagram of an embodiment of the present invention, Fig. 2 is a diagram showing the vibration mode of the suspension when flutter occurs when no damper is installed, and Fig. 3 is a diagram showing the vibration mode of the suspension when flutter occurs with the device shown in Fig. 1. This is an experimental graph in which the actual damping effect was investigated. 30...King pin shaft, 34...Body, 38...Arm, 40...Damper.

Claims (1)

[Claims for Utility Model Registration] In a configuration in which the tire is rotated about the axis of the lower suspension arm together with the kingpin shaft by operating the steering wheel, one end is fixed to the kingpin shaft and the other end is fixed to the kingpin shaft. an arm having a free end extending obliquely toward the tire; the arm being coupled to the free end of the arm and the body of the vehicle so as to damp vibrations relative thereto; A steering flutter damping device comprising a damper arranged at a predetermined inclination relative to the damper.