JPS63119476U - - Google Patents

Description

[Brief explanation of the drawing]

1 to 9 show an embodiment of this invention, in which FIG. 1 is a vertical cross-sectional view showing a schematic configuration of the main part of a hydraulic actuator for rear wheel steering of a four-wheel steering system, and FIG. FIG. 3 is a plan view showing the rear suspension device, FIG. 3 is a perspective view thereof, FIG. 4 is a schematic configuration diagram of the entire four-wheel steering device of the vehicle, and FIG. 5 shows a state in which the hydraulic actuator is held in a neutral position. A vertical cross-sectional view of the main part, FIG. 6 is a vertical cross-sectional view of the main part showing a state in which the hydraulic actuator is steered in the left steering direction, and FIG. 7 is a longitudinal cross-sectional view of the main part showing a state in which the hydraulic actuator is steered in the right steering direction. A vertical sectional view of the main part, FIG. 8 is a characteristic diagram showing the spring characteristics of the first and second spring members,
FIG. 9 is a characteristic diagram showing the relationship between the steering angle of the steering wheel and the steering state of the rear wheels, and FIG. 10 is a characteristic diagram showing the relationship between the steering angle of the steering wheel and the pressure generated by the hydraulic actuator of a conventional four-wheel steering system. It is a characteristic diagram. 1... Rear wheel, 13... Front wheel, 15... Front wheel steering mechanism, 37... Rear wheel steering mechanism, 38... Hydraulic actuator, 43... Piston rod, 48...
Neutral position holding mechanism, 49...Cylinder case, 5
4...Rod side protruding part, 55...Case side protruding part, 56...Central spring receiving part, 57, 58...Fixed spring receiving part, 59...First spring member, 60...
Second spring member, 63...First cylindrical member (holding part of case side protrusion), 64...Second cylindrical member (holding part of fixed spring receiving part), 65...Third
Cylindrical member (holding part of fixed spring receiver).

Claims (1)

[Scope of utility model registration request] By displacing the suspension arm of the rear suspension device within the elastic deformation area of the rear suspension bushing relative to the vehicle body, the rear wheels are suspended so that they can be steered, and together with a front wheel steering mechanism that steers the front wheels, hydraulic pressure is applied to the rear wheels. In a four-wheel steering device equipped with a rear wheel steering mechanism for steering by an actuator, a rod-side protruding portion is provided on an outer circumferential surface of a piston rod of the hydraulic actuator and protrudes toward an inner circumferential surface of a cylinder case of the hydraulic actuator. A case-side protrusion protruding from the inner circumferential surface of the cylinder case of the hydraulic actuator forms a central spring receiving part, and the rod-side protrusion is opposed to the case-side protrusion protruding from the inner peripheral surface of the cylinder case of the hydraulic actuator. Fixed spring receivers are formed on the inner circumferential surface of the cylinder case, and fixed spring receivers are arranged on both sides of the central spring receiver and are spaced apart from each other, and a spring member is formed between the center spring receiver and the fixed spring receivers on both sides. a neutral position holding mechanism for holding the piston rod of the hydraulic actuator in a neutral position by the biasing force of these spring members by arranging the piston rods in a compressed state and facing each other in a compressed state; A four-wheel steering device characterized in that a holding part of the side protrusion and a holding part of the fixed spring receivers on both sides are each formed in a divided state.