JPH0355351B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in a vehicle steering system that steers front wheels and rear wheels by steering operation of a steering wheel.

An offset arm that rotates in conjunction with the steering wheel, a push-pull link whose front end is connected to the arm and can freely move back and forth, and a push-pull link that is connected to the rear end of the link and moves a tie rod for steering the rear wheels left and right. A vehicle steering device that simultaneously steers the front wheels and rear wheels by operating the steering wheel and changing the steering ratio of the front and rear wheels in proportion to the steering angle. (Patent Application No. 1983-47743 (Patent Application No. 1983)
-164478), etc.) were previously provided by the applicant.

According to such a steering device, it is possible to steer the rear wheels in the same direction as the front wheels by operating a small steering angle of the steered wheels, and it is also possible to steer the rear wheels in the opposite direction by operating a large steering angle, thus making it possible to drive at high speed. In addition to improving maneuverability inside the U
When making a turn or entering or exiting a parking lot, the steering angle is increased to obtain a small turning radius, which improves maneuverability of the vehicle.

However, in the past, a new tie rod for the rear wheels was used to steer the rear wheels.

On the other hand, when the vehicle is running at high speed, it is desirable that the amount of steering of the rear wheels be small and that the steering response be good.

The present invention does not require a new tie rod for the rear wheels, has a simple structure, makes the amount of steering of the rear wheels small enough to be suitable for high-speed driving, and provides a vehicle with good steering response. It was created for the purpose of providing a steering device.

In order to achieve such an object, the present invention connects one of an arm member and a rod member that support a rear wheel knuckle arm to both left and right ends of a connecting member that is pivotably supported to the vehicle body at the center so as to be horizontally swingable. At the same time, the other side is connected to the vehicle body, and an offset is provided near one end of the connecting member, or to either the left or right of the arm member or rod member connected and supported by the connecting member, and which rotates in conjunction with the steering wheel. The gist is that the rear end of the push-pull link, whose front end is connected to the arm, is connected.

Embodiments of the present invention will be described in detail below with reference to the accompanying drawings. 1 to 3 show a first embodiment of the present invention, and FIG. 1 shows a schematic configuration of a vehicle equipped with a steering system according to the first embodiment, except for the main parts of the front wheel steering system. FIG. 2 is a plan view illustrating the main part thereof in a perspectively enlarged manner for convenience, with the part omitted.

As is well known, the tip of a steering shaft of a steering wheel (not shown) that is steered by a driver is incorporated in a front wheel steering gear box.

When the front wheel steering gear is of the rack-and-pinion type, the drive pinion 1 integrated at the tip of the steering shaft and the rack 3 formed on the right half of the rack shaft 2 mesh with each other, as shown in FIG. When the steering wheel is steered, the rack shaft 2 moves left and right, and the front wheel tie rods 6, 6 connected to the left and right ends of the rack shaft 2 via ball joints 5, 5 move left and right, causing the knuckle arms (not shown) to rotate left and right. By moving the front wheels, the front wheels are steered.

On the other hand, a new rack 4 is formed on the left half of the rack shaft 2, and a driven pinion 7 is meshed with this rack 4 substantially horizontally. This rack 4 is the rack 3
are formed opposite to the rack shaft 2 in the front and back.

The base of an offset arm 9 is fixedly integrated with the pinion shaft 8 of the driven pinion 7, and the front end of a long push-pull link 11 is pivotally connected to the tip of the offset arm 9.

The push-pull link 11 is arranged in the longitudinal direction of the vehicle, and its rear end is pivotally supported near the left end of a connecting arm 12 arranged in the left-right direction of the vehicle.

A pin 13 is welded vertically through the left and right center portions of the connecting arm 12, and the upper and lower portions of this pin 13 are loosely fitted into upper and lower bracket plates 21, 21 fixed at the left and right center of the vehicle body, respectively.
In addition, the axial movement of the pin 13 is restricted. Thereby, the connecting arm 12 is pivoted to the vehicle body so as to be horizontally swingable together with the pin 13 using the pin 13 as a fulcrum.

Bifurcated portions 14, 14 are formed at both left and right ends of the connecting arm 12 and are spaced apart from each other in the front and rear, respectively, and a pin 15 passes through the bifurcated portions 14 in the front and rear direction.
It is carried.

The inner end of the lower arm 22 is fitted onto the outer periphery of the intermediate portion of the pin 15 supported by the bifurcated portion 14 via a collar 16 and a baked rubber bushing 17.

The lower arm 22 is of the so-called A-arm type, in which the outer end is formed into a bifurcated portion 23 that is spaced apart in the front and rear, and a pin 24 is passed through the bifurcated portion 23 in the longitudinal direction and supported. The inner end of the knuckle arm 31 is loosely fitted and supported on the outer periphery.

A ball joint 35 is attached to the upper inner end of the nutcle arm 31.
The rear end of the radius rod 41 is connected via the
The front end of the radius rod 41 is pivotally supported by a pin 43 to a rod bracket 42 fixed to the vehicle body, and the axle 3 protrudes outward from the knuckle arm 31.
A rear wheel 33 supported by 2 is configured to rotate left and right about the ball joint 35 as a pivot.

In the above, the neutral position for steering is initially set when the offset arm 9 is oriented in the left-right direction (in the figure, the tip is to the left).

When the steering wheel is steered, for example, to the right, the driven pinion 7 rotates to the left via the drive pinion 1 and the rack shaft 2.
The offset arm 9, which is integral with the rotor, rotates at the same time, and the tip of the offset arm 9 moves rearward until 1/4 rotation, and the push-pull link 11 moves rearward. Due to this backward movement of the push-pull link 11, the connecting arm 12 rotates slightly to the left together with the pin 13 about the pin 13 as a fulcrum.

Knuckle arms 31, 31 are pivoted to pivots 35, 3 by radius slots 41, 41 supported on the vehicle body.
5, the connecting arm 12
The left lower arm 22 pivots to pivot 3 due to the left rotation of
5 as a fulcrum, and the right lower arm 22 pivots its inner end forward as a fulcrum. At this time, rubber bushes 17, 1 are interposed between the pins 15, 15 carried by the bifurcated parts 14, 14 at both ends of the connecting arm 12 and the inner ends of the lower arms 22, 22, respectively.
7 undergoes compressive elastic deformation.

Due to the rotation of the lower arms 22, 22, the two knuckle arms 31, 31 are both slightly rotated clockwise about the pivots 35, 35, and thus the rear wheels 3
3 and 33 are steered slightly to the right, same as the front wheels. The amount of steering at this time is minute because the lower arm 22 is interposed like a lever.

Next, when the steering wheel is returned to the neutral position, the push-pull link 11 and the connecting arm 1
2 responds, and the lower arms 22, 22 are connected to the pins 1 of the bifurcated parts 14, 14 at both ends of the connecting arm 12.
Rubber bushing 17, 1 interposed between 5, 15
It quickly returns to the initial position due to the return spring force of 7,
Therefore, the rear wheels 33, 33 can be quickly returned to the neutral position.

In the case of the small steering angle operation described above, the rear wheels can be steered in the same direction as the front wheels at a small steering angle, and the rear wheels can also quickly return to the neutral position, so the vehicle The responsiveness during high-speed driving is extremely good.

Furthermore, since the amount of steering of the rear wheels in the opposite direction to the front wheels is similarly small, there is no interference with the tire house of the rear wheels.

Further, by variously changing and combining the pivot point of the push-pull link with respect to the connecting arm and the length of the lower arm, various lever ratios can be obtained.

Furthermore, similar effects can be obtained by connecting the push-pull link to one of the lower arms.

By the way, if the restoring force of the rubber bushing is strengthened, the rear wheels can be held in the neutral position even if the rear wheel steering system becomes free.

Next, a second embodiment of the present invention will be described based on FIGS. 4 to 6.

First, attach the drive pinion 101 integrated at the tip of the steering shaft to the rack 10 on the right half of the rack shaft 102.
3, and on the other hand, a driven pinion 107 is meshed approximately horizontally with the rack 104 on the left half of the rack shaft 102.

And the pinion shaft 1 of the driven pinion 107
The base of an offset arm 109 is fixedly integrated with the offset arm 109, and the front end of a long push-pull link 111 is pivotally connected to the tip of the offset arm 109. The total length of this push-pull link 111 is smaller than that of the first embodiment.

The push-pull link 111 is arranged in the longitudinal direction of the vehicle, and its rear end is pivotally supported near the left end of a connecting arm 112 arranged in the left-right direction of the vehicle.

A sleeve 113 vertically passes through the left and right center portions of the connecting arm 112 and is integrally welded thereto, and a collar 115 is attached to the inner periphery of the sleeve 113 with a baked rubber bushing 114 interposed therebetween.

This sleeve 113 is rotatably installed vertically between upper and lower bracket plates 121, 121 fixed at the left and right center of the vehicle body, and the collar 1 is attached to the inner circumference of the sleeve 113 via a baked rubber bush 114.
A pin 116 is fixed vertically inside 15, and this pin 11
6 is fixed to the bracket plates 121, 121. As a result, the connecting arm 112 is pivoted to the vehicle body so as to be horizontally swingable about the pin 116, which is a fixed shaft, as a fulcrum.

U-shaped planar rod brackets 117, 117 that open rearward and outward are fixed to the left and right ends of the connecting arm 112, respectively.
The front ends of 41 and 141 are pivotally supported by pins 118 and 118.

At the rear end of this radius slot 141 is a ball joint 1.
The upper inner end of the knuckle arm 131 is connected to the knuckle arm 131 via a shaft 35, and a rear wheel 133 is supported on an axle shaft 132 that projects outward from the knuckle arm 131.

In addition, the inner end of the knuckle arm 131 is loosely fitted and supported by a pin 124 to a bifurcated portion 123 at the outer end of an A-arm type lower arm 122.
The inner end of the bracket is supported by a pin 152 on an arm bracket 151 fixed to the vehicle body and having a substantially U-shaped planar shape that opens outward. That is, the inner end of the lower arm 122 is fitted onto the outer periphery of the intermediate portion of the pin 152 via a collar 125 and a baked rubber bushing 126.

In the above, when the offset arm 109 is oriented in the left-right direction (in the figure, the tip is to the right), it is initially set as the neutral position for steering.

When the steering wheel is steered, for example, to the right, the driven pinion 107 rotates to the left via the drive pinion 101 and the rack shaft 102, and the offset arm 109 rotates at the same time, and is turned off until 1/4 rotation. The tip of the set arm 109 faces forward,
The push-pull link 111 moves forward. This forward movement of the push-pull link 111 causes the connecting arm 112 to rotate slightly to the right about the fixed shaft 116 as a fulcrum. At this time, connecting arm 112
A rubber bush 114 interposed between the central sleeve 113 and the fixed shaft 116 is torsionally deformed.

Since the knuckle arms 131, 131 are supported by the lower arms 122, 122 which are supported on the vehicle body via rubber bushes 126, 126, the left radius rod 141 moves forward and the right radius slot 141 moves backward due to the right rotation of the connecting arm 112. Accordingly, the left Katsukuru arm 1
31 rotates forward together with the lower arm 122 using the inner end of the left lower arm 122 as a fulcrum, and conversely, the right knuckle arm 131 rotates slightly rearward together with the lower arm 122 using the inner end of the right lower arm 122 as a fulcrum. At this time, the pins 152, 152 supported by the left and right arm brackets 151, 151 fixed to the vehicle body and the lower arms 122, 122
Rubber bushes 126, 126 interposed between the inner ends of the rubber bushes 126 and 126, respectively, are compressively and elastically deformed.

In this way, the rear wheels 133, 133 are steered slightly to the right in the same way as the front wheels. The amount of steering at this time is minute because the knuckle arm 131 itself is moved back and forth using the inner end of the lower arm 122 as a fulcrum.

Next, when the steering wheel is returned to the neutral position, the push-pull link 111 and the connecting arm 112 respond, contrary to the above, and the connecting arm 112
is quickly returned to its initial position by the resilient force of the rubber bush 114 between the central sleeve 113 and the fixed shaft 116, and the radius slot 1 connected to both ends of the connecting arm 112
41 and 141 also responded, lower arms 122 and 12
2 is also arm bracket 151, pin 15 of 151
Rubber bushing 12 interposed between 2,152
The return force of the rear wheels 133, 126 quickly returns to the initial position, and therefore the rear wheels 133, 133 return to the neutral position extremely quickly.

In the case of the small steering angle operation described above, the rear wheels can be steered in the same direction as the front wheels at a small steering angle, and the rear wheels can also quickly return to the neutral position, so the vehicle The responsiveness during high-speed driving is extremely good.

Furthermore, since the amount of steering of the rear wheels in the opposite direction to the front wheels is similarly small, there is no interference with the tire house of the rear wheels.

Further, by variously changing the pivot point of the push-pull link with respect to the connecting arm, various lever ratios can be obtained.

Furthermore, in the second embodiment, unlike the first embodiment, the lower arm is not incorporated into the rear wheel steering system like a lever, so it is possible to increase the lever ratio.

Furthermore, similar effects can be obtained by connecting the push-pull link to either the left or right of the lower arm or the radius rod.

By the way, if the restoring forces of the radius rod bushing and the lower arm bushing are strengthened, even if the rear wheel steering system becomes free, the rear wheels can be held in the neutral position by the restoring force of each bushing.

As is clear from the above description, according to the present invention, one of the arm member and the rod member that supports the rear wheel knuckle arm is attached to the end of the connecting member which is pivotably supported to the vehicle body so as to be horizontally swingable at the center. At the same time, the other end of the push-pull link was connected to the vehicle body, and the rear end of the push-pull link, whose front end was connected to an offset arm that rotates in conjunction with the steering wheel, was connected near one end of the connecting member. There is no need for a new tie rod for the rear wheels, which simplifies the structure.Furthermore, the amount of steering of the rear wheels is small and the return to the neutral position is quick, so it is especially suitable for high-speed vehicles. It is possible to exhibit excellent advantages such as extremely good steering response during driving.

The same effect can be obtained even if a push-pull link is connected to either the left or right of the arm member or rod member connected and supported by the connecting member.

[Brief explanation of drawings]

The drawings show an embodiment of the present invention, and FIG. 1 is an explanatory plan view of a schematic configuration of a vehicle equipped with the steering device of the first embodiment, and FIGS. 2 and 3 are respectively similar to FIG. 1. 2-2 line, 3-3 line sectional view, Figure 4 is the 2nd
1, FIG. 5, and FIG. 6 of the embodiment are sectional views taken along lines 5-5 and 6-6 in FIG. 4, respectively. In addition, 9,109 in the drawing is an offset arm, 1
1,111 is push pull link, 12,112
is the connecting arm, 22, 122 is the lower arm, 31, 131 is the knuckle arm, 33, 13
3 is the rear wheel, and 41,141 is the radius slot.

Claims (1)

[Claims] 1. In a vehicle steering system in which the rear wheels are steered together with the front wheels by the steering operation of the steering wheel, one of the arm member and the rod member supporting the rear wheel knuckle arm is connected to the vehicle body, and the other is connected to the center part. The rear end of the push-pull link is connected to both left and right ends of a connecting member which is pivotally supported on the vehicle body so as to be horizontally swingable, and the front end is connected to an offset arm that rotates in conjunction with the steering wheel. A steering device for a vehicle, which is connected to one end of a member, or to either the left or right side of an arm member or rod member connected and supported by the connecting member.