JPH059982Y2 - - Google Patents

Description

[Detailed description of the invention] [Field of industrial application] The present invention is a four-wheel steering system in which the maximum steering angle of the front wheels is greater than the maximum steering angle of the rear wheels, and the steering angle ratio of the front and rear wheels can be set to 1. This invention relates to a front wheel steering angle limiting device for a vehicle.

[Prior art] Four-wheel steering vehicles are known (for example, Japanese Patent Application Laid-Open No. 1983-1999).
175469), an anti-phase four-wheel steering mode in which the rear wheels are steered in the opposite phase to the front wheels, an in-phase four-wheel steering mode in which the rear wheels are steered in the same phase as the front wheels, a so-called crab driving mode, and a non-steering mode in which the rear wheels are not steered. It is possible to switch between two-wheel steering modes and three steering modes.

By the way, in a vehicle where the maximum steering angle of the front wheels is larger than the maximum steering angle of the rear wheels and the steering angle ratio of the front and rear wheels can be set to 1, in the same phase mode as shown in FIG. When the steering angle θF exceeds the maximum rear wheel steering angle θRmax, the rear wheel steering angle θR remains unchanged.
The front wheel steering angle θF increases to the maximum steering angle θF max. Therefore, this range A (=θF max − θR max)
Since θF>θR, it is impossible to perform parallel movement with complete in-phase, that is, a steering angle ratio of 1, so-called crab running.

[Object of the invention] Accordingly, an object of the invention is to provide a front wheel steering angle limiting device for a four-wheel steered vehicle that enables a complete in-phase four-wheel steering mode.

[Structure of the invention] According to the invention, in a four-wheel steering vehicle in which the maximum steering angle of the front wheels is larger than the maximum steering angle of the rear wheels and the steering angle ratio of the front and rear wheels can be made 1, A stopper bolt is provided upright, a stopper is provided on the front wheel shaft body on the trajectory of the bolt head of the stopper bolt opposite to this stopper bolt, a pin is provided upright near the end of the stopper on the vehicle center side, and a pin is attached to the stopper bolt. An adjustment lever is pivotally mounted, consisting of a clevis-shaped lever part that holds the stopper and an adjuster part bent from the lever part, and the adjuster part adjusts the steering angle of the front wheels to the maximum of the rear wheels when the bolt head is locked. A shift lever is pivotally connected to the upper end of the pin, a spring is provided between the shift lever and the adjustment lever, and an actuator is attached to a bracket on the stopper side of the front axle body. A return spring is provided between the end of the bracket and the end of the shift lever.

[Operations and Effects of the Invention] Therefore, in the same-phase four-wheel steering mode, the actuator is operated to insert the adjustment lever between the stopper and the stopper bolt via the shift lever and spring. As a result, the front wheel steering angle is reduced by the thickness of the insertion part of the adjustment lever,
Full in-phase four-wheel steering mode can be enabled.

[Examples] Examples of the present invention will be described below with reference to the drawings.

In FIGS. 1 and 2, which show one side of the front axle, there is a stopper bolt 2 on the front axle main body 3 side of the front wheel knuckle 1 (not shown).
has been erected.

On the other hand, a stopper 4 is provided to protrude from the front axle body 3 opposite to the stopper bolt 2, that is, on the trajectory of the bolt head 2a during steering. Therefore,
The stopper bolt 2 can be adjusted so that the steering angle when the stopper 4 locks the bolt head 2a becomes the maximum front wheel steering angle θF max.

Near the end of this stopper 4 on the vehicle center side,
A pin 5 is provided upright, and a stopper 4 is attached to the pin 5.
A clevis-shaped lever portion 6a that holds the
An adjustment lever 6 is pivotally mounted, and includes an adjustment portion 6b that is bent outward from the lever portion 6a and is approximately parallel to the front axle axis in the non-operating state shown. The thickness of the adjusting portion 6b is determined so that when the adjusting portion 6a locks the bolt head 2a (FIG. 3), the front wheel steering angle θF becomes equal to the rear wheel maximum steering angle θR max. Further, a shift lever 8 is pivotally attached to the upper end of the pin 5, and a coil spring 7 is provided in a free state (not twisted) between the shift lever 8 and the adjustment lever 6.

In addition, on the side of the front axle body 3 on the stopper 4 side,
An actuator 10 is fixedly mounted via a bracket 9 so that its axis is substantially parallel to the front axle axis. A return spring 11 is adjusted between the end of the bracket 9 and the end of the shift lever 8 for biasing the shift lever 8 in a counterclockwise direction. 8a is locked to the operating end 10a of the actuator 10.

The actuator 10 is an air cylinder in the illustrated example, and a switching valve (not shown) provided in the middle of the air pipe 12 is connected to a control circuit (not shown).

In operation, in the same-phase four-wheel steering mode, the control circuit switches the switching valve, guides air from an air reservoir (not shown) to the air cylinder 10, and extends the air cylinder 10. As a result, the shift lever 8 rotates clockwise, and the adjustment lever 6 is rotated clockwise via the coil spring 7, thereby bringing the adjustment portion 6b into contact with the stopper 4. Therefore, as shown by the chain line in FIG.
The front wheel steering θF at that time becomes the maximum steering angle θF max, and this steering angle θF max is equal to the maximum steering angle θR max of the rear wheels. As a result, as shown in Fig. 6, θF max = θR max Therefore, the steering ratio θF/θR is 1.
Therefore, it is possible to perform steering in a complete in-phase four-wheel steering mode within the front wheel steering restriction range B.

Further, when the front wheels are switched to the same phase mode when the front wheels are in the maximum steering state, the shift lever 8 is rotated clockwise as shown in FIG. However, the adjusting portion 6b of the adjusting lever 6 interferes with the stopper bolt 2, and the adjusting lever 6 is locked at a rotating position before the normal rotating position (FIG. 3). As a result, the coil spring 7 is twisted, and the adjustment lever 6 is biased clockwise. Therefore,
As the front wheel faces the neutral position and the stopper bolt 2 moves, the adjusting portion 6b is rotated to the normal position by the biasing force of the coil spring 7.

Furthermore, when the same phase mode is switched to another mode when the front wheel steering angle is limited and the front wheels are at the maximum steering angle, the air cylinder 10 contracts and the return spring 11 moves the shift lever 8 to its original position (second position). Figure). However, since the adjuster portion 6b is held between the stopper bolt 2 and the stopper 4, the adjuster lever 6 cannot rotate. As a result, the coil spring 7 is twisted and urges the adjustment lever 6 counterclockwise. Therefore, the front wheel faces the neutral position and the stopper bolt 2 moves, and the adjustment lever 6 returns to its original position (second position) due to the biasing force of the coil spring 7.
Figure) is restored. In this way, the air cylinder 10 can be operated when switching to the same phase mode without being restricted by the position of the stopper bolt 2, that is, the front wheel steering angle, due to the twist of the coil spring 7.
Easy to control.

[Summary] As explained above, according to the present invention, the same phase 4
In wheel steering mode, the adjuster lever is inserted between the stopper and the stopper bolt to make the maximum steering angle of the front wheels equal to the maximum steering angle of the rear wheels, allowing for complete in-phase mode driving.

[Brief explanation of drawings]

Figure 1 is a side view showing one embodiment of the present invention;
The figure is a top view when not in operation, Figure 3 is a top view when in operation, Figure 4 is a top view of the main parts explaining when the front wheels are switched to the same phase mode when the steering angle is at its maximum, and Figure 5 is the same. A top view of the main parts to explain when the same phase mode is switched to another mode when the front wheels are at the maximum steering angle in the phase mode, Figure 6 is a steering angle characteristic diagram explaining the effects of the present invention, and Figure 7 is a conventional diagram. FIG. 2 is a steering angle characteristic diagram of a four-wheel steered vehicle. θF max...Front wheel maximum steering angle, θR max...Rear wheel maximum steering angle, 1...Natsukuru, 2...Stopper bolt, 3...Front axle body, 4...Stopper, 6...
Adjustment lever, 7...Coil spring, 8
...Shift lever, 10...Air cylinder, 11
...Return spring.

Claims (1)

[Scope of utility model registration request] The maximum steering angle of the front wheels is greater than the maximum steering angle of the rear wheels.
And the steering angle ratio of the front and rear wheels can be set to 1.4
In a wheel-steering vehicle, a stopper bolt is provided upright on the front wheel nut, a stopper is provided on the front wheel axle body opposite the stopper bolt on the trajectory of the bolt head of the stopper bolt, and a pin is installed near the end of the stopper on the vehicle center side. An adjustment lever consisting of a clevis-shaped lever part that holds the stopper and an adjuster part bent from the lever part is pivotally attached to the pin, and the adjuster part locks the bolt head. In some cases, the front wheel steering angle is configured to be equal to the maximum rear wheel steering angle, a shift lever is pivotally connected to the upper end of the pin, a spring is provided between the shift lever and the adjustment lever, and the front wheel steering angle is A front wheel steering angle limiter for a four-wheel steering vehicle, characterized in that an actuator is fixed to a stopper side of a main body via a bracket, and a return spring is provided between an end of the bracket and an end of a shift lever. Device.