JPH0664418A - Steering wheel suspension device - Google Patents

Abstract

PURPOSE:To secure restoring force of a steering device during steering, even if kingpin offset and kingpin inclination of a wheel are set to zero. CONSTITUTION:A knuckle 7 supported with a car body frame 11, as being able to move upward and downward freely, through a lower arm 8 and an upper arm 13, comprises a control arm 7c extending from the kingpin axis K to the inside of the car body. The lower end of a damper 18 is connected to the control arm 7c through the first rod 19, and connected to the lower arm 8 through the second rod 20. When a wheel W is turned by a steering device, as a ball joint 21 set on the control rod 7c is displaced to the outside of the car body, from the full line position to the chain line position in the figure, the first rot 19 is pulled up from the full line position to the chain line position and compresses the damper 18. Consequently, restoring force of the compressed damper 18 generates a force by which the wheel W is restored to the neutral position where it was before the steering.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a steering wheel suspension system for an automobile, and more particularly, to the free ends of an upper arm and a lower arm pivotally supported by a vehicle body, which are respectively connected to the upper and lower parts of a knuckle supporting the steering wheel. However, the present invention relates to an improvement in which the vertical movement of the knuckle is buffered by a damper.

[0002]

2. Description of the Related Art Such a steering wheel suspension system is already known, for example, as disclosed in Japanese Patent Laid-Open No. 3-7608.

[0003]

To reduce the torque steer phenomenon peculiar to a front engine / front drive vehicle (hereinafter referred to as FF vehicle), a kingpin offset,
That is, it is desirable to reduce the distance between the point where the kingpin axis intersects the road surface when viewed from the front of the vehicle body and the center of the ground contact surface of the wheel. However, since the restoring torque of the steering device at the time of a large low steering angle is proportional to the kingpin offset, setting the kingpin offset small as described above causes a problem that the restoring torque of the steering device at the time of a large low steering angle becomes insufficient.

The present invention has been made in view of the above circumstances, and even if the kingpin offset is set small, it is possible to sufficiently secure the restoring torque of the steering device at a low steering angle and a large steering angle. The purpose is to provide a device.

[0005]

In order to achieve the above object, the present invention connects free ends of an upper arm and a lower arm pivotally supported by a vehicle body to an upper part and a lower part of a knuckle supporting a steered wheel, respectively. Then, in the steering wheel suspension device configured to buffer the vertical movement of the knuckle with a damper,
The lower end of the damper is connected to a position inside the vehicle body with respect to the kingpin axis of the knuckle via a first rod, and is also connected to a vehicle body or a lower arm via a second rod.

[0006]

Embodiments of the present invention will be described below with reference to the drawings.

FIGS. 1 to 3 show a first embodiment of the present invention. FIG. 1 is a view of the left front wheel of an FF vehicle seen from the rear of the vehicle body, and FIG. 2 is an explanatory view of the action corresponding to FIG. FIG. 3 is a three-direction arrow view of FIG. Since the right front wheel has the same structure as the left front wheel, its illustration is omitted.

As shown in FIGS. 1 to 3, a wheel hub 2 is splined and fixed by a nut 3 to an outer end of a wheel drive shaft 1 driven by a power unit (not shown). The flange 2 ₁ of the wheel hub 2 is wheel disc 4 and the brake disc 5 of the wheel W is fastened.

A ball bearing is provided on the outer periphery of the wheel hub 2.
The knuckle 7 supported via the ring 6 extends downward.
Vicious lower arm 7_L, Upper arm 7 extending upward_U, Extend to the front of the vehicle
Vibrating steering arm 7_NAnd the upper arm 7_UFrom the middle part of the car body
Control arm 7 extending toward_CAre integrally formed. Knuckle 7
The lower arm 8 that supports the lower part of the
The body frame is connected via a pair of rubber bush joints 9 and 10.
It is pivotally supported by the ram 11 and its tip is ballge.
The lower arm 7 of the knuckle 7 through the joint 12 _LPivotally
To be done. Upper arm 1 supporting the upper part of the knuckle 7
3 is a rubber bush joint with a forked base end
When it is pivotally supported by the body frame 11 via 4, 15
In addition, the tip of the
Clou 7 upper arm 7_UBe pivoted to. And the knuckle 7
Via the lower arm 8 and the upper arm 13, the vehicle body frame is
It is supported by the arm 11 so as to be vertically movable. At this time, Nack
Lower arm 7 of Le 7_LBall joint 12 and upper arm 7_UThe Bo
The kingpin axis K that connects to the wheel joint 16 of the wheel W
It is located in the plane of rotation and therefore the king pin of wheel W
Both the fset and kingpin inclination are set to zero.
Is determined.

The steering arm 7 _N of the knuckle 7 is a tie rod 17
Is connected to a steering handle (not shown) through which the knuckle 7 rotates left and right around the kingpin axis K to steer the wheels W.

The upper end of the damper 18 for suspending the wheel W is connected to the vehicle body frame 11, and the lower end thereof is connected to the knuckle 7 and the lower arm 8 via two rods 19 and 20. That is, the ball joint 21 provided on the control arm 7 _C of the knuckle 7 and the rubber bush joint 22 provided on the lower end of the damper 18 are connected by the first rod 19 arranged substantially vertically, and the base of the lower arm 8 is connected. The rubber bush joint 23 provided in the vicinity of the end portion and the rubber bush joint 24 provided at the lower end of the damper 18 are connected by the second rod 20 arranged substantially horizontally. At this time, as is clear from FIGS. 2 and 3, the position of the ball joint 21 connecting the control arm 7 _C of the knuckle 7 and the first rod 19 is biased toward the inside of the vehicle body with respect to the kingpin axis K, Further, as is clear from FIG. 3, the position of the ball joint 21 is displaced toward the rear of the vehicle body with respect to the center of the wheel W.

Next, the operation of the first embodiment of the present invention having the above construction will be described.

As is apparent from FIGS. 1 and 2, the kingpin axis K connecting the ball joint 12 of the lower arm 7 _L of the knuckle 7 and the ball joint 16 of the upper arm 7 _U lies in the vertical plane passing through the center of the wheel W. Therefore, both the kingpin offset and the kingpin tilt angle of the wheel W are set to zero. Therefore, even if torque is transmitted from the drive wheels W to the road surface, so-called torque steering that prevents the wheels W from being steered in an undesired direction is prevented.

Generally, if both the kingpin offset and the kingpin tilt angle are set to zero, the tie rod 17
When the wheel W is steered to the left or right by pushing or pulling, the restoring torque of the steering device tends to become insufficient, and this tendency becomes remarkable especially at a low speed and a large steering angle. However, according to the steering device of the present invention, the restoring torque of the steering device can be generated as follows.

That is, for example, when the left wheel W, which is a turning outer wheel, is steered in the direction of arrow a in FIG. 3 in order to turn the vehicle to the right, the knuckle 7 rotates clockwise around the kingpin axis K. The ball joint 21 provided on the control arm 7 _C projecting from the kingpin axis K to the inside of the vehicle body is displaced rearward of the vehicle body and outside the vehicle body as shown by a chain line in FIGS. 2 and 3. As a result, the lower end of the damper 18 is pulled up by the first rod 19 connecting the ball joint 21 of the control arm 7 _C and the rubber bush joint 22 of the damper 18, and the damper 18 is slightly compressed. When the damper 18 is compressed in this way, the restoring force of the damper 18 urges the wheel W toward the neutral position before turning, so that the restoring torque can be generated in the steering device.

On the contrary, when the left wheel W, which is the turning inner wheel, is steered in the direction of arrow b in FIG. 3 in order to turn the vehicle leftward, the ball joint 21 is displaced forward and the inside of the vehicle is turned. Is also slightly displaced. However, the displacement of the ball joint 21 depends on the first rod 19
Is almost not moved up and down, and as a result, the expansion and contraction of the damper 18 is substantially not performed.

Therefore, when turning the vehicle by turning the wheels W, the restoring torque is generated in the wheel W which is the outer wheel of the turning, and the restoring torque is not generated in the wheel W which is the inner wheel of the turning. However, due to the centrifugal force acting on the vehicle during turning, a large load is applied to the outer turning wheel, whereas a small load is applied to the inner turning wheel.
The restoring torque generated in the turning outer wheel effectively acts, and it is possible to give a sufficient restoring torque to the steering device as a whole.

In the above embodiment, in order to avoid the interference with the wheel drive shaft 1, the control arm 7 _C of the knuckle 7, the first rod 19, the damper 18, and the second rod 20 are placed in the vehicle body more than the center of the wheel W. In the case of a rear drive vehicle that is biased rearward, but does not have the wheel drive shaft 1, they can be arranged at the center of the wheel W in the front-rear direction. With this configuration, the damper 18 can be compressed via the first rod 19 regardless of whether the wheel W is steered in the left or right direction, so that the restoring torque is generated in both the turning outer wheel and the turning inner wheel. Is possible.

The rubber bush joint 23 may be provided on the vehicle body frame 11 instead of the lower arm 8. However, in this case, it is preferable to use a ball joint because the swing angle becomes large.

Next, the second aspect of the present invention will be described with reference to FIGS.
Examples will be described. Here, FIG. 4 is a view of the left front wheel of the FF vehicle as seen from the rear of the vehicle body, FIG. 5 is an explanatory view of the action corresponding to FIG. 4, and FIG.

In the second embodiment, the upper arm 7 _{U of the} knuckle 7 is used.
It is characterized by the structure of the upper arms 13 ₁ and 13 ₂ that connect the upper arm 7 _U and the vehicle body frame 1. That is, the upper arm 7 _U of the knuckle 7 of the second embodiment bypasses the upper inner edge of the wheel W and extends above the wheel W, and the two ball joints 16 ₁ , 16 ₂ of the upper arm 7 _U Front and rear upper arms 13 ₁ , 1 connected to each other
3 ₂ is pivotally supported on the body frame 11 via a rubber bush joint 14, 15. Further, the second rod 20 is pivotally supported on the vehicle body frame 11 via a ball joint 23.

As is apparent from FIG. 6, the extension lines of the _two upper arms 13 ₁ and 13 _{2 to} the outside of the vehicle body intersect on the center line of the wheel W, and the intersection is the virtual turning center. 16 '. Therefore, the wheel W is connected to the ball joint 12 of the lower arm 7 _L of the knuckle 7 and the virtual steering center 1
It will be steered around the kingpin axis K connecting 6 '. And, since the kingpin axis K is in the vertical plane passing through the center of the wheel W as in the first embodiment,
Both the kingpin offset and the kingpin tilt angle become zero, and the occurrence of torque steer is prevented.

Moreover, since the upper arm 7 _U is extended to the outside of the wheel W, it is not necessary to store the upper arms 13 ₁ and 13 ₂ in the narrow inner space of the wheel disc 4, and the degree of freedom in design can be increased. It will be possible. Also since the divided upper arm 13 _1, 13 ₂ into two, the upper arm 13 ₁ relative to the virtual turning center 16 ', 13
The outer end of ₂ can be moved to the inside of the vehicle body to prevent interference with the fender.

Thus, also in the second embodiment, the first rod 19 is pulled upward to compress the damper 18 in accordance with the turning of the wheel W which serves as the outer wheel for turning, and the steering force is restored by the damper 18. A restoring force can be generated in the device.

In this embodiment, the second rod 20 is pivotally supported on the vehicle body frame 11 by the ball joint 23, but in order to suppress the swing angle, a rubber bush joint is attached to the lower arm 8 as in the first embodiment. You may pivot it through. Further, in this embodiment, the upper arms 13 ₁ , 13
_{Although 2} is a double joint type, the lower arm 8 can also be a double joint type.

Although the embodiments of the present invention have been described in detail above, the present invention is not limited to the above embodiments, and various small design changes can be made.

[0027]

As described above, according to the present invention, the lower end of the damper, which cushions the vertical movement of the knuckle supported by the upper arm and the lower arm, is located inside the vehicle body from the kingpin axis of the knuckle via the first rod. Since the knuckle is rotated in order to steer the wheels, the damper is compressed through the first rod and the compressed damper is restored because the damper is connected to the position and connected to the vehicle body or the lower arm through the second rod. A restoring force can be applied to the steering device by the force. As a result, even if the kingpin offset and the kingpin tilt angle of the wheel are set small in order to prevent torque steer, it is possible to generate an appropriate restoring force in the steering device.

[Brief description of drawings]

FIG. 1 is a rear view of a left front wheel suspension system according to a first embodiment.

FIG. 2 is an explanatory diagram of an operation corresponding to FIG.

FIG. 3 is a three-direction arrow view of FIG.

FIG. 4 is a rear view of the left front wheel suspension system according to the second embodiment.

FIG. 5 is an explanatory diagram of an operation corresponding to FIG.

FIG. 6 is a view in the direction of arrow 6 in FIG.

[Explanation of symbols]

 7 Knuckle 8 Lower Arm 11 Body Frame (Car Body) 13 Upper Arm 18 Damper 19 First Rod 20 Second Rod K Kingpin Shaft W Wheel (Steering Wheel)

Claims (1)

[Claims] 1. A knuckle (7) for supporting a steering wheel (W).
The free ends of the upper arm (13) and the lower arm (8) pivotally supported by the vehicle body (11) are connected to the upper and lower parts of the vehicle, respectively, and the vertical movement of the knuckle (7) is damped (1).
8) In a steering wheel suspension system configured to be damped by 8), the lower end of the damper (18) is connected to a position inside the vehicle body with respect to the kingpin shaft (K) of the knuckle (7) via a first rod (19). In addition, the steering wheel suspension device is characterized in that it is connected to the vehicle body (11) or the lower arm (8) via the second rod (20).