JPH021177Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a rear wheel steering device for a front wheel drive vehicle or the like.

Generally, front-wheel drive vehicles have the problem of a large turning radius, and to overcome this problem, some vehicles have been designed to allow the rear wheels to also be steered.

Such a rear wheel steering device is constructed as shown in FIG. 1, for example. That is, 1 in the figure is an axle beam, and this axle beam 1 is supported by trailing arms 2, 2. The front ends of these trailing arms 2, 2 are attached to a vehicle body (not shown) via bushes 3, 3. Knuckles 5, 5 are rotatably attached to both ends of the trailing arm 1 via king pins 6, 6.
Further, 8 is a lateral rod, one end of which is attached to the axle beam 1 via a bushing 9, and the other end is attached to the vehicle body via a rubber bushing 10.
It is configured to suppress lateral deflection. Further, arms 11, 11 are provided to project forward from the knuckles 5, 5, respectively.
The tips of these arms 11, 11 are connected by a tie rod 12, forming a so-called Atkerman mechanism. A knuckle arm 13 is provided rearwardly protruding from one of the knuckles 5, and this knuckle arm 13
A control rod 14 is connected to the tip of the rod via a bush 16. Further, a steering cylinder mechanism 15 is connected to the control rod 14 via a universal joint 17. This steering cylinder mechanism 15 is attached to the vehicle body and is configured to reduce unsprung weight. Further, the steering cylinder mechanism 5 is telescopically operated by hydraulic pressure supplied in response to, for example, a steering operation of the front wheels (not shown), thereby steering the rear wheels and locking the rear wheels in a neutral position. The vehicle is equipped with a mechanism to lock the rear wheels in a neutral position, for example, when driving at high speeds. Further, the bush 16 and the universal joint 17 are connected to the bushes 9 and 10 of the lateral rod 8.
The control rod 1 is located at the same position both horizontally and vertically relative to the axle beam 1.
4 is configured to displace along the same locus as the lateral rod 8, so as to prevent so-called link interference in which the control rod 14 is displaced relative to the axle beam 1 when the axle beam 1 moves up and down. It is configured.

By the way, in such a device, when the axle beam 1 moves up and down, the lateral rod 8 rotates around the rubber bush 10 on the vehicle body side, and the bush 9 on the axle beam 1 side draws an arc-shaped trajectory around the rubber bush 10. This causes the axle beam 1 to be displaced in the lateral direction. In order to prevent this lateral displacement of the axle beam 1,
As mentioned above, the rubber bush 10 is interposed at the attachment point between the lateral rod 8 and the vehicle body, and the rubber bush 10 is configured to absorb lateral displacement of the axle beam 1 by deformation. However, if this is done, when the axle beam 1 moves up and down, a shift will occur in the loci of movement of the lateral rod 8 and the control rod 14, and the control rod 14 will be displaced relative to the axle beam 1. 5 will rotate slightly.

In order to prevent such a problem, it may be possible to attach the steering cylinder mechanism to the axle beam side, but if this is done, the unsprung weight increases, resulting in a problem that impairs the performance of the suspension system. It is also conceivable to insert a rubber bushing or the like at the attachment point between the control rod and the knuckle arm to absorb the relative displacement between the control rod and the axle beam. However, this causes problems such as inaccurate steering due to deformation of the rubber bushings when steering the rear wheels.

In addition, the conventional type mentioned above requires space for the arrangement of the control rod and steering cylinder mechanism, and requires special modifications to the vehicle body in order to secure this space. This results in a problem that places restrictions on the arrangement of the exhaust system.

The present invention was developed based on the above circumstances, and its purpose is to prevent relative displacement of each member when the axle beam moves up and down, and to prevent an increase in unsprung weight and to save space. An object of the present invention is to provide a rear wheel steering device with improved efficiency.

In other words, the present invention consists of an axle disposed in the vehicle width direction, a lateral rod having one end connected to one end of the axle and the other end connected to the vehicle body, and a lateral rod provided at both ends of the axle to freely steer the rear wheels. and a tie rod that connects the ends of the arms protruding from these knuckles, one end of which is connected to the knuckle on one end of the axle, and the other end of which is connected to the steering cylinder mechanism. A control rod is connected to one end of the steering cylinder mechanism, and the other end of the steering cylinder mechanism is connected to the other end of the lateral rod, so that the steering cylinder mechanism is supported by the lateral rod.

Therefore, the control rod and steering cylinder mechanism are located close to and along the lateral rod, allowing the overall device to be compact. In addition, when this invention is installed, it is only necessary to slightly expand the space where the lateral rod is placed, so there is less modification to the car body, and there are no restrictions on the placement of the fuel tank or exhaust system. Less is. Furthermore, the control rod and steering cylinder mechanism described above are displaced along the same trajectory as the lateral rod, and no relative displacement between this control rod and the axle beam occurs. Furthermore, since the steering cylinder mechanism and the like are attached to the lateral rods, about half of their weight is supported by the vehicle body, and the increase in unsprung weight is minimal.

Hereinafter, embodiments of the present invention will be described with reference to FIGS. 2 to 8. 2 and 3 show a first embodiment of the invention. In the figure, 101 is an axle beam, and this axle beam 101 is supported by trailing arms 102, 102. And these trailing arms 10
The front end portions of 2 and 102 are attached to the vehicle body (not shown) via bushiers 103 and 103. Further, a nutcle 10 is connected to both ends of the trailing arm 101 via king pins 106, 106.
5, 105 is rotatably attached. Further, arms 111, 111 are provided to project forward from the nuticles 105, 105, respectively. The tips of these arms 111, 111 are connected by a tie rod 112, forming a so-called Atkerman mechanism.

A lateral rod 121 is connected to one end of the axle beam 101 via a bush 122.
One end of is connected. A box-shaped cylinder accommodating portion 125 is provided at the other end of the lateral rod 121. The other end of this lateral rod 121 is connected to a bracket 124 on the vehicle body side via a rubber bush 123. A steering cylinder mechanism 126 is housed in the cylinder accommodating portion 125 of the lateral rod 121, and this steering cylinder mechanism 126 is connected to the bush 13.
0 to this cylinder accommodating portion 125, that is, to the lateral rod 121. Further, a knuckle arm 120 is provided on one of the knuckles 105 to protrude rearward. And the piston rod 128 of the steering cylinder mechanism 126
A control rod 127 is connected to the control rod 127, and the tip of this control rod 127 is connected to the bush 12.
9 to the knuckle arm 120 on one end of the axle beam. This bush 129 is connected to the control rod 121.
It is located at the same position in both the vertical and lateral directions with respect to the bush 122 on the axle beam 101 side. The above-mentioned steering cylinder mechanism 126 is telescopically operated by the hydraulic pressure supplied in response to the steering operation of the front wheels (not shown), so that it steers the rear wheels and also maintains a neutral position when driving at high speeds. It is configured to be mechanically or hydraulically locked in position to maintain the rear wheels in a neutral position.

Next, the operation of this embodiment will be explained. When the axle beam 101 is displaced vertically, the lateral rod 121 tries to rotate around the rubber bush 123 on the vehicle body side, and this axle beam 101 tries to displace laterally, but this lateral displacement is caused by the rubber bush 123. This is absorbed by the deformation, and the axle beam 101 moves up and down vertically. Since the steering cylinder mechanism 126 is attached to the lateral rod 121, the steering cylinder mechanism 126 and the control rod 127 are displaced together with the lateral rod 121, and the control rod 127 is moved relative to the axle beam 101. There will be no physical displacement. Therefore, when the axle beam 101 moves up and down, the knuckles 105, 105 do not rotate. In addition, since this steering cylinder mechanism 126 is attached to the lateral rod 121, about half of its weight is supported by the vehicle body, and the increase in unsprung weight is small, so it will not cause a decrease in the performance of the suspension system. do not have.

As described above, according to the present invention, the control rod and the steering cylinder mechanism are arranged along the lateral rod, so the entire device can be made smaller, space efficient, and fewer modifications to the vehicle body are required. There are no restrictions on the placement of the fuel tank or exhaust system. Furthermore, the control rod and the steering cylinder mechanism are displaced along the same trajectory as the lateral rod, and no relative displacement occurs between the control rod and the axle beam. Furthermore, since the steering cylinder mechanism and the like are attached to the lateral rods, about half of their weight is supported by the vehicle body, and the unsprung weight increases only slightly, which is a great effect.

[Brief explanation of drawings]

FIG. 1 is a perspective view of a conventional example. FIGS. 2 and 3 show an embodiment of the present invention, with FIG. 2 being a perspective view and FIG. 3 being a plan view. 101... Axle arm, 105... Knuckle, 120... Knuckle arm, 121... Lateral rod, 124... Bracket, 125...
Cylinder housing part, 126...Steering cylinder mechanism,
127...Control rod.

Claims (1)

[Scope of utility model registration request] A rear suspension having an axle member disposed in the vehicle width direction, and one lateral rod connected at one end to the axle member and connected to the vehicle body at the other end and disposed substantially in the vehicle width direction,
Furthermore, left and right knuckles are rotatably supported at both ends of the axle member so as to rotatably support the rear wheels and enable the rear wheels to be steered, and arms projecting from the left and right knuckles, respectively. , a tie rod that connects the tips of these arms to each other, a control rod that has one end connected to one of the above knuckles and is arranged approximately in the width direction of the vehicle, and a control rod that is connected to the other end of the control rod and has the other end connected to the vehicle. a steering cylinder mechanism provided to drive displacement in the width direction, the one end of the control rod being disposed on the one end side of the lateral rod, and the steering cylinder mechanism disposed on the other end of the lateral rod. A rear wheel steering device, characterized in that it is disposed on the side and connected to the lateral rod.