JPH05345511A - Vehicle traveling stabilizer - Google Patents

Abstract

PURPOSE:To ensure stable straight traveling in a vehicle whose front wheels are driven and rear wheels are steered by contracting-operating a tie rod according the detection signal of a backward position detection sensor for giving prescribed toe-in to rear wheels, thus eliminating the unstable posture of a vehicle body at the time of backward traveling. CONSTITUTION:In a vehicle whose front wheels are driven and rear wheels are steered, the knuckle arms 11b of steering knuckles 7, 8 where rear wheels 37 are fitted on the right and left of a rear axle 2 in a rear wheel steering mechanism 1, and a bell crank 14 pivoted in its center are connected to each other by a pair of right and left actuator tie rods 16, 17 so that they may be steered. Moreover, actuators 20, 20 which can expand and contract the tie rods 16, 17 based on the detection signal of a backward position detection sensor by operating a shift lever to a backward shift position at least are installed at the right and left actuator tie rods 16, 17 to give prescribed toe-in to right and left rear wheels 37 by contracting the tie rods 16, 17.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a traveling stabilizer for a vehicle such as a forklift truck which is driven by front wheels and steered by rear wheels during traveling.

[0002]

2. Description of the Related Art Conventionally, in a vehicle of this type, such as a forklift, there is a mast for cargo handling on the front side, and about 80% of the total cargo handling load and its own weight is applied to the front wheels. In addition to being adopted, forklifts, unlike those with a small amount of reverse movement such as automobiles, carry out cargo handling work at about 50% forward and reverse, so the left and right rear wheels should be parallel. It is adjusted and installed in the vehicle and equipped with a nearly constant speed forward / reverse transmission.

[0003]

However, when carrying out cargo handling work by means of this forklift, if luggage is placed on the fork and forward operation is performed, straightness, that is, flapping in the left-right direction, occurs even if the rear wheels are parallel. It is possible to obtain straightness with relatively few occurrences, but especially in the case of reverse driving, since the rear wheels are parallel and no toe-in is given, there is a problem that the straightness deteriorates due to flapping during running. was there.

The present invention has been made to solve the above-mentioned conventional problems, and an object of the present invention is to provide a vehicle running stabilizing device which is capable of imparting a toe-in to the steered wheels (rear wheels) according to the running direction. It is what

[0005]

SUMMARY OF THE INVENTION To solve the above technical problems, the present invention provides a vehicle with front-wheel drive and rear-wheel steering,
A knuckle arm of a steering knuckle having rear wheels attached to the left and right of a rear axle of the rear wheel steering mechanism and a bell crank pivotally attached to a central portion are steerably connected by a pair of left and right tie rods. By operating at least the reverse shift position of the shift lever, an actuator capable of expanding and contracting the tie rod according to the detection signal of the reverse position detection sensor is provided, and the tie rod can be shortened to give a predetermined toe-in to the left and right rear wheels. It exists in the vehicle travel stabilizer configured in.

[0006]

By virtue of the above-mentioned structure, the fluctuation in the backward movement can be eliminated, and the stable straight traveling can be secured.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a plan view of a rear wheel steering mechanism, and FIG.
1 is a rear view, in which the upper side indicates the forward side (front side) and the lower side indicates the reverse side (rear side). The rear wheel steering mechanism 1 is connected to a rear axle 2, steering knuckles 7 and 8 attached to the left and right of the rear axle 2, a bell crank 14 attached to a central portion, and the bell crank 14 and the left and right steering knuckles 7 and 8. It is composed of actuator tie rods 16 and 17.

In this rear axle 2, upper and lower axle plates 3 and 4 are reinforced and connected by front and rear support plates 5 and 6 at a predetermined interval to form a space W between the upper and lower axle plates 3 and 4. The axle plates 3 and 4 are provided with bearing portions 3a and 4a at a predetermined kingpin angle. The steering knuckles 7 and 8 mounted between the left and right bearing portions 3a and 4a are formed symmetrically, and are housed between the bearing portions 3a and 4a and have a boss portion 9a having an insertion hole through which the kingpin 12 is inserted. 9b
The wheel spindle 10 is attached to the bosses 9a and 9b.
The a and 10b and the nuck arms 11a and 11b are formed at a predetermined angle, and are rotatably connected via a king pin 12.

Further, as shown in FIG. 1, the bell crank 14 is rotatably provided by a bell crank pin 13 between upper and lower axle plates 3 and 4 at a predetermined position P on the front side on the center line C of the vehicle. As shown in FIG. 2, the connecting portions 15a and 15b of the actuator tie rods 16 and 17 are vertically aligned at a predetermined radial position corresponding to the center line C from the mounting position P as shown in FIG.
Further, a steering connecting portion 15c for connecting to a power steering cylinder (not shown) is integrally formed at a position at a predetermined angle from the one connecting portion 15b. Between the bell crank 14 thus provided and the left and right steering knuckles 7, 8, the actuator tie rods 16, 17 of the vehicle travel stabilizing device are attached using the space W of the rear axle 2.

One of the tie rods 16 is connected by an end of the knuckle arm 11a of the left steering knuckle 7 shown in the drawing, a connecting portion 15a of the bell crank 14 and a ball joint 23, and the other tie rod 17 is connected to the knuckle arm of the right steering knuckle 8 shown in the drawing. 11b and the connecting portion 15b of the bell crank 14 and the ball joint 23 are connected, and the left and right actuator tie rods 16 and 17 are provided in the same configuration. Therefore, the actuator tie rod 17 on the right side of the drawing will be described. The actuator / tie rod 17 is provided so as to be expandable / contractible via an actuator (a hydraulic cylinder is exemplified in this example) 20 such as a hydraulic cylinder or an electric cylinder, and is formed separately into a base tie rod 18 and an operating tie rod 19. The actuator 2 is provided at the end of the tie rod 18.
No. 0 cylinder 21 is detachably attached integrally, and the actuator 20 is attached to the end of the operating tie rod 19.
The piston rod 22 is detachably attached integrally and is linked so as to be expandable and contractible. The actuator tie rods 16 and 17 provided in this manner are configured to apply the toe-in A to the left and right rear wheels 37 by the control circuit of the vehicle travel stabilizing device shown in FIG.

Next, the control circuit will be described with reference to FIG. A forward position detecting sensor 26 is provided on the forward shift position F side of the illustrated shift lever 25, and a reverse position detecting sensor 27 is provided on the reverse shift position R side thereof. Both of these sensors 26, 27 are relayed to a controller 28. In addition, a circuit of a vehicle key switch 29 is relayed to the controller 28. This controller 2
Reference numeral 8 inputs a signal in the ON state of the key switch 29 and a signal from the forward position detecting sensor 26 or the reverse position detecting sensor 27 of the shift lever 25, and outputs the signal to the power unit 31 and the electromagnetic switching valve 32 of the hydraulic circuit 30. The discharge pipe 34 of the pump 33 of the power unit 31 is connected to the P port of the electromagnetic switching valve 32.
The port is connected to the piston chamber 20a of the actuator 20 of the left and right tie lots 16 and 17 via a branch pipe 35, and the B port of the electromagnetic switching valve 32 is branched to the rod chamber 20b of the actuator 20 of the left and right tie lots 16 and 17. It is connected through a pipe 36.

In the control circuit thus arranged, when the shift lever 25 is moved to the forward shift position F side, it is detected by the position detection sensor 26, and this detection signal is input to the controller 28, which inputs the controller 28 to the power unit. At the same time that 31 is activated,
The controller 28 excites the solenoid SOL1 of the solenoid operated directional control valve 32, and the pressure oil is supplied to the left and right tie rods 1 via the branch pipe 35.
6 and 17 are sent to the piston chamber 20a of the actuator 20, and the operating tie rod 19 is extended to a predetermined dimension to set the rear wheel 37 to be parallel A0 via the knuckle arms 11a and 11b (see FIG. (See a)), after a lapse of a predetermined set time, the operation of the electromagnetic switching valve 32 is stopped to return to the neutral position, the branch pipes 35 and 36 are closed, the operation tie rod 19 is fixed, and the power unit 31 is stopped. In this state, the left and right actuating tie lots 19 are fixed, and the left and right rear wheels 37 are maintained in parallel A0 for forward driving.

When the shift lever 25 is moved to the reverse shift position R, it is detected by the position detection sensor 27, and this detection signal is input to the controller 28. By this input, the controller 28 operates the power unit 31, and at the same time, the controller 28 is activated. Solenoid switching valve 32
The solenoid SOL2 is excited to send pressure oil to the rod chambers 20b of the actuators 20 of the left and right tie rods 16 and 17 through the branch pipe 36, and the actuating tie rods 19 are shortened by a predetermined dimension to actuate the knuckle arms 11a and 11b. It is set so that a predetermined toe-in A is applied to the rear wheel 37 via the valve (see Fig. (B)), and when the predetermined set time elapses, the operation of the solenoid operated directional control valve 32 is stopped to return to the neutral position and the branch Tube 3
The power unit 31 is stopped by closing 5, 36 and fixing the operating tie rod 19. In this state, the left and right actuating tie lots 19 are fixed, and the toe-in A is maintained on the left and right rear wheels 37 to perform the reverse drive.

As described above, when the shift lever 25 is operated to the forward movement F side during the cargo handling by the forklift, the forward movement shift position F is detected by the position detection sensor 26 as described above. A signal is input to the controller 28, and the controller 28 outputs the signal to the power unit 31 and the solenoid SOL1 of the electromagnetic switching valve 32 by this input to output the left and right tie rods 16, 1.
The tie rod 19 of the actuator 20 of No. 7 is extended to a predetermined size to set the rear wheel 37 in parallel via the knuckle arms 11a and 11b in the same manner as in the conventional case, so that the same straightness as in the conventional case is secured. be able to.

Particularly, during the reverse loading and unloading operation by the forklift, the shift lever 25 is moved to the reverse shift position R.
When it is shifted to, it is detected by the position detection sensor 27, and this detection signal is input to the controller 28, and by this input, the controller 28 outputs it to the power unit 31 and the solenoid SOL2 of the electromagnetic switching valve 32 to output the actuators of the left and right tie rods 16 and 17. Knuckle arms 11a, 11b are operated by shortening the operation tie rod 19 of 20 by a predetermined dimension.
Since a predetermined toe-in A is set to be applied to the rear wheel 37 via the wheel, by providing this toe-in A, the conventional flutter at the time of reverse travel is eliminated and a stable straight traveling property is ensured. Therefore, the degree of fatigue of the occupant can be reduced.

In the above embodiment, when the shift lever 25 is operated to the forward movement F, the left and right rear wheels 37 are excited so as to be set in parallel. For example, as shown in FIG. Is set so that the toe-in A on the forward side is given by a predetermined dimension expansion operation, it can be expected to ensure straightness at the time of forward movement.

[0017]

As described above, according to the present invention, the position detection sensor detects when the shift lever is moved to the reverse shift position, particularly when the vehicle is moving backward, and the detection signals detect the left and right tie rods. Since the actuating tie rod of the actuator is shortened by a predetermined dimension to give a predetermined toe-in to the left and right rear wheels via the knuckle arm, by adding this toe-in, the conventional Fluctuation is eliminated and stable straightness can be secured,
It is possible to reduce the fatigue level of the occupant.

[Brief description of drawings]

FIG. 1 is a plan view of a rear wheel steering mechanism.

FIG. 2 is a rear view of FIG.

FIG. 3 is a control circuit diagram of an actuator / tie rod.

4 (a), (b) and (c) are operation explanatory views of the left and right rear wheels.

[Explanation of symbols] 1 rear wheel steering mechanism 2 rear axle 7,8 steering knuckle 11 knuckle arm 14 bell crank 16,17 actuator / tie rod 19 actuating tie rod 20 actuator 25 shift lever 27 reverse position detection sensor 37 rear wheel A toe-in

Claims (1)

[Claims] 1. In a vehicle with front-wheel drive and rear-wheel steering, a knuckle arm of a steering knuckle having rear wheels attached to the left and right of a rear axle of the rear-wheel steering mechanism and a bell crank pivotally attached to a central portion form a left-right pair. The tie rods are connected so that they can be steered, and the left and right tie rods are provided with actuators capable of expanding and contracting the tie rods according to the detection signal of the reverse position detection sensor by operating at least the reverse shift position of the shift lever. A vehicle running stabilizer that is configured to be shortened so that a predetermined toe-in can be applied to the left and right rear wheels.