JPS59106369A - Rear wheel steering neutral holder for rear wheel suspender of car - Google Patents

Abstract

PURPOSE:In a steering system for steering the front and rear wheels simultaneously through steering operation, to hold the steering angle zero during free time of rear wheel steering system by providing a holding device for resetting the rear wheel to neutral position and holding on rear wheel suspender. CONSTITUTION:In a steering system where rear wheel as well as front wheel is steered by means of linkage shaft 24, input shaft 31, crank arm (not shown), eccentric pin 33 and left/right tie rods 13, etc. through steering operation of steering wheel, a holding device 80 is provided between strut rod 71 of rear wheel shock absorber 17 and chassis. When the rear wheel steering system went free, said holding device 80 will engage a push roller 83 to a curved recess section 82 through centering function due to pressure contact against a centering cam 81 caused by a coil spring 88 of push roller 83 thus to hold the rear wheel 16 to neutral position.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a vehicle equipped with a steering system that steers both the front wheels and the rear wheels by steering operation of the steering wheels. The present invention relates to a steering neutral holding device for a rear wheel in a rear wheel suspension system that maintains the steering at a neutral steering position.

The rotation required for rear wheel steering is output from the front wheel steering system via the linkage member as rotation of a swing link or eccentric pin, etc., and the front and rear wheels are rotated so that the steering ratio of the front and rear wheels is changed in proportion to the steering angle. Vehicle steering device that steers the wheels simultaneously (patent application 1982-
No. 118698, Japanese Patent Application No. 57-47743, etc.) were previously provided by the present 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. In addition to improving the maneuverability of the vehicle, it is also possible to increase the steering angle to obtain a small turning radius when making U-turns or manoeuvring in a parking lot, which improves the maneuverability of the vehicle. .

The present invention has been made for the purpose of maintaining the rear wheels in a neutral steering position and reducing the steering angle to zero even when the rear wheel steering system becomes free in a vehicle equipped with the above-mentioned steering system. 0 In order to achieve such an object, the present invention urges members such as a strut rod, a cylindrical shock absorber, and a lower arm constituting a rear wheel suspension system to return the rear wheel to a neutral steering position. The gist is that a holding device is attached to hold the device.

Embodiments of the present invention will be described in detail below with reference to the accompanying drawings.
FIG. 1 is a perspective view showing an example of a schematic configuration of a front and rear wheel steering device. The front end of a steering wheel shaft 2 of a steering wheel 1 is connected to a rack-and-pinion type front wheel steering gear box 2.
0, and as is known, inside the gear box 20, there is another rack formed to the left of the rack that meshes with the drive pinion at the tip of the handle shaft 2, and a driven pinion (both not shown in the figure). ) are in mesh with each other, and tie rods 3.3 are connected to both ends of the rack shaft 21, which protrudes from the left and right sides of the gear box 20, respectively. tie rod 3.3
A knuckle arm 4.4 is connected to the outer end of the knuckle arm 4.4, and the front wheels 6,6 are supported by axles 5,5 projecting outwardly from the knuckle arm 4.4.

As is known, the front wheels are steered by the left and right movement of the rack shaft 21.

On the other hand, the rear part of the driven pinion shaft 22 that meshes with the rank on the left half of the rack shaft 21 is led out rearward from the gear box 20, and is connected to a long linkage shaft 24 via a universal joint 23. An input shaft 31 is connected to the rear end of the rotary shaft 24 via a universal joint 25.

The input shaft 31 is a rotating member that is arranged in alignment with the left-right center line of the vehicle and supported by a bearing placket 32, and a crank arm (not shown in the figure) is attached to the rear end of the input shaft 31. ) An eccentric pin 33 is fixedly integrated therewith.

A joint member 34, which connects and supports the left and right tie rods 13.degree. 13, is loosely fitted into and supported by the eccentric pin 33.

On the other hand, the joint member 34 is supported by the vehicle body via an arm 35, a link 36, and a link bracket 37, and is restricted from swinging.

Furthermore, a knuckle arm 14 is attached to the outer end of the tie rod 13.13.
．． 14 is connected to the knuckle arm 14. A rear wheel 16.16 is supported on an axle 15.15 that projects outwardly from the knuckle arm 14.

When the steering wheel 1 is operated, the rotation necessary for steering the rear wheels is output to the driven pinion shaft 22, and the rotation is input to the input shaft 31 of the rear wheel steering system via the linkage shaft 24, rotates to the left or right.

As the input shaft 31 rotates, the eccentric pin 33 integrally provided at the rear end rotates as a crank, and as the eccentric pin 33, which is initially set perpendicular to the input shaft 31, rotates as a crank, the joint rotates. Member 34, tie rod 13.1
3. The rear wheels 16.16 are steered via the knuckle arms 14.14.

That is, at small steering angles up to 7 rotations from the initial neutral position of the eccentric pin 33, the rear wheels 16 are steered in the same phase as the front wheels 6, and at large steering angles exceeding - rotations, they are steered to opposite phases.

Incidentally, both the front wheel knuckle arm 4 and the rear wheel knuckle arm 14 are buffered and supported by a shock absorber 7.17 installed between them and the vehicle body.

In the first embodiment of the present invention, as shown in FIGS. 2 and 3, the struts of the rear wheel shock absorber 17 are
A holding device 80 is interposed between the steering wheel 71 and the vehicle body to bias and hold the rear wheels back to the neutral steering position.

This holding device 80 includes a centering cam 81 and an engaging element 8.
3 and a pressing means 84.

First, the strut rod 71 is protruded from the upper part of the rear wheel shock absorber 17, and the centering cam 81, which is a plate cam, is fixed to the upper end of the strut rod 71.
Make 2 stick out. A comb push 73 is baked on the upper outer periphery of the shaft rod 72, and a g race 75 of the thrust bearing 74 is baked on the lower part of the comb push 73.

As is known, the thrust bearing 74 is constructed by interposing a ball 76 between an A/P race 75 and a lower race 77, and the lower race 77 of the thrust bearing 74 is fixed to the upper surface of the centering cam 81. Also, the rear/main race 75 is fixedly integrated with the vehicle body constituent members. As a result, the strut rod 71 is rotatably supported by the vehicle body, and therefore the rear wheel shock absorber 17 is rotatable with respect to the vehicle body, thereby performing the aforementioned steering of the rear wheels 16.

The centering cam 81 is a plate cam with a curved recess l formed in a part of its outer periphery, and an engaging element 83 is formed in this curved recess 82.
are pressed together as described below.

That is, a cylinder 85 is fixed to a vehicle body structural member while remaining substantially horizontal, a bushing rod 86 is made to protrude from the cylinder 85, and a roller holder 87 having a U-shaped side surface is fixed to the tip of the bushing rod 86. 87, the second lower wall 87a of the roller holder 87 of the pressing means 84, which is formed by compressing a coil spring 88;
The bushing roller 83, which is an engager, is inserted between the bins 89 and 87b.
Supported by

In this way, the bushing roller 83 urged forward by the pressing means 84 is brought into pressure contact with the curved recess 82 of the centering cam 81. In this case, when the rear wheels 16 are at the neutral steering position where the steering angle is zero, the 70-wheel drive roller 83 is brought into pressure contact with the curved recess 82 of the centering cam 81 for initial setting.

If the rear wheel steering system becomes free, the centering action of the bushing roller 83 by pressure contact with the centering cam 81 will cause the rear wheel 16 to be engaged and held in the curved recess 82. can be held in the steering neutral position.

The shape and size of the curved concave portion 82 of the centering cam 81 are appropriately set depending on the steering limit of the rear wheel 16. Further, the engaging element and the pressing means may of course have other configurations.Next, a second embodiment of the present invention will be explained based on FIG. 4.

In the second embodiment, a cylindrical rear wheel shock absorber 1 is used.
A return spring member 180 is interposed between 70 and the vehicle body.

As is known, the rear wheel shock absorber 170 includes a cylinder 171, a piston rod 172 that slides inside the cylinder 171 and projects upward, a lower seat (not shown) fixed to the outer periphery of the cylinder 171, and the piston rod 172.
The upper seat 1-175 is fixed to the upper outer periphery of the seat via a collar 174, and these lower seats and upper seat 175
It consists of a coil spring 176 compressed in between.

A rubber bushing 180 with a strong restoring force is burned on the outer periphery of the cylindrical portion 175a of the upper seat 175 of the rear wheel shock absorber 170, and a cylindrical holder 177 is further burned on the outer periphery of this rubber bushing 180. This cylindrical holder 1
A flange plate portion 177a is formed at the bottom of γ7.

To install the rear wheel shock absorber 170 on the vehicle body,
The flange play 1/portion 177a of the cylindrical holder 177 is attached to the vehicle body component 190 such as the tire house with the bolt 1 from below.
It is decided to join with 91...

Since the cylindrical shock absorber 170 is rotatably supported with respect to the vehicle body by the rubber bushing 180 having a strong restoring force, the rear wheel 16 can be maintained at the neutral steering position even if the rear wheel steering system becomes free. I can do it.

Next, a third embodiment of the present invention will be described in detail with reference to FIGS. 5 to 7, together with a front and rear wheel steering device different from the above.

A drive pinion 201 shown in FIG. 5 is integrated with the tip of the handle shaft (not shown), and a rack 20 formed on the right half of the drive pinion 201 and rack shaft 202
3 meshes with each other, while a driven pinion 205 is inserted approximately horizontally into a rank 204 formed on the left half of the rack shaft 202.
mesh.

Both racks 203 and 204 are formed to face the rack shaft 202 in the front and rear directions.

Then, the base of an offset arm 2070 is fixedly integrated with the pinion shaft 20G of the driven pinion 205, and a bush pull link 20 is attached to the tip of the offset arm 207.
Pivotally connect the front ends of 8.

The push-pull link 208 is disposed in the front-rear direction of the vehicle 97, and the rear end is pivoted to the left end of the connecting arm 211 disposed in the left-right direction of the vehicle.The push-pull link 208 has a sleeve extending vertically in the left-right center of the connecting arm 211, which is pivoted to the left end of the connecting arm 211 whose rear end is disposed in the left-right direction of the vehicle. 212 penetrates and is welded together, and a collar 214 is attached to the inner periphery of this sleeve 212 with a rubber bushing 213 interposed therebetween.

Upper and lower bracket plates 2 fixed to the left and right center of the vehicle body
This sleeve 212 is rotatably installed vertically between 90 and 290, and a rubber bush 213 is attached to the inner periphery of the sleeve 212.
A pin 215 is fixed vertically into the collar 214 installed through the bracket plate (290, 2).
Fixed at 90. This connects the connecting arm 211.
At both left and right ends of the connecting arm 211, which is horizontally swingable on the vehicle body using a fixed shaft pin 215 as a fulcrum, are U-shaped planar brackets 216 that open rearward and outward, respectively.
216 is fixed, and this rod bracket 216.21
6, the front ends of left and right radius rods 221, 221 are pivotally supported by pins 217, 217, respectively.

An upper inner end of a knuckle arm 223 is connected to the rear end of the radius rod 221 via a ball joint 222, and a rear wheel 225 is supported by an axle shaft 224 that projects outward from the knuckle arm 223.

Further, the inner end of the knuckle arm 223 is loosely fitted and supported by a pin 226 to a bifurcated portion 232 at the outer end of a so-called A-arm type lower arm 231, and the inner end of this lower arm 231 is fixed to a component of the vehicle body and extends substantially outward. A support hole 233 is formed in the inner end of the lower arm 231, which is supported by a pin 235 on an arm bracket 291 having a planar U-shape that can be opened. Further, a collar 234 is baked on the inner periphery of the rubber bushing 280, and the outer periphery of the intermediate portion of the pin 235 is inserted and fixed into this collar 234.
35 represents the front and rear walls 291a of the arm bracket 291 which is U-shaped in plan.

It is fixed at 291a.

In the above, when the offset arm 207 is oriented in the left-right direction (the tip is to the right in the illustration), it is initially set as the neutral position for steering.When the steering wheel is operated, the offset arm 207 rotates. Then, the radius rods 221 and 221 move back and forth in opposite directions through the back and forth movement of the push-pull link 208 and the horizontal swing of the connecting arm 211, and thus the lower arm 231°23
The knuckle arm 223 degrees 223 swings around the inner end of the rear wheel 1 as a fulcrum, and the rear wheels 225, 225 are steered.

That is, at a small steering angle from the initial neutral position of the offset arm 207 to one rotation, the rear wheels can be steered in the same direction as the front wheels with a small steering angle, and the connecting arm 211 and the lower arm 231. Since the rear wheels are pivoted to the vehicle body via the rubber bushes 213 and 280, the rear wheels can quickly return to the neutral position, resulting in extremely good responsiveness when the vehicle is running at high speed.

In particular, in the third embodiment, the inner end of the lower arm 231 is swingably supported by a rubber bush 280, which is a return spring member with a strong restoring force, on a vehicle body component.
Even if the rear wheel steering system becomes free, the rear wheels 225 can be maintained at the neutral steering position.

In the above embodiments, the holding device according to the present invention is applied to two types of front and rear wheel steering devices, but the present invention can be applied to any other type of front and rear wheel steering devices.

As is clear from the above description, according to the present invention, the cam, the retainer, the suppressing means, By interposing a return spring member, etc.
Since the holding device is configured to bias and hold the rear wheels in the neutral steering position, even if the temporary rear wheel steering system becomes free, the steering angle of the rear wheels will be zero and this steering angle will be zero. condition can be maintained.

[Brief explanation of drawings]

The drawings show each embodiment of the present invention, and FIG. 1 is a perspective view showing an example of a schematic configuration of a front and rear wheel steering device, and FIG. FIG. 3 is a plan view of the same, FIG. 4 is a longitudinal side view showing a second embodiment of the present invention, and FIG. 5 is a schematic configuration of a front and rear wheel steering device different from the above. 6 is a sectional view taken along line 6-6 in FIG. 5, and FIG. 7 is a sectional view taken along line 7-7 in FIG. 5, showing a third embodiment of the present invention. In the drawing, 1 is the steering wheel, 6 is the front wheel, 16.225 is the rear wheel,
17.170 is the rear wheel shock absorber, 71 is the same strut rod, 231 is the same lower arm, 80,180
．． 280 is a holding device, 180 and 280 are return spring members, 81 is a cam, 83 is an engaging element, and 84 is a pressing means.

Claims (4)

[Claims] (1) In a vehicle equipped with a steering device that steers both the front wheels and the rear wheels by steering the steering wheel,
A steering neutral holding device for a rear wheel in a rear wheel suspension system for a vehicle, characterized in that the rear wheel suspension system is provided with a holding device for urging and holding the rear wheel in a neutral steering position. (2) A cam is provided on the strut rond constituting the rear wheel suspension system, and an engager is provided on the vehicle body that presses against the cam via a pressing means to constitute the holding device. Rear wheel steering/upright holding device 0 in the rear wheel suspension system of the vehicle described in item 1 (3) The vehicle according to claim 1, wherein the holding device is constructed by interposing a return spring member between the cylindrical shock absorber constituting the rear wheel suspension device and the vehicle body. A rear wheel steering neutral holding device in a rear wheel suspension system. (4) The rear wheel suspension system for a vehicle according to claim 1, wherein the holding device is constructed by interposing a return spring member between a lower arm constituting the rear wheel suspension system and the vehicle body. Rear wheel steering neutral maintenance device.