JPH0573627B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a steering device, and particularly to a steering device that adds auxiliary steering to steering wheels depending on driving conditions, etc., thereby improving the driving performance of a vehicle.

[Prior art] As a conventional steering device, for example, the
No. 88873 discloses one in which an actuator for moving the gear housing is attached to the tip of a drive arm output from a rack-and-pinion gear housing, and is driven according to steering conditions.

(Problems to be Solved by the Invention) However, in such a conventional steering device, the moving arm protruding from the gear housing is positioned at a position that includes the length of the arm with respect to the gear housing axis to drive the gear housing. Since the structure was designed to apply force, a force in the axial direction of the gear housing and a moment in the direction of tilting the gear housing are generated, and friction with the support body due to bending of the gear housing increases. Alternatively, when the support body is attached via an elastic body, there is a problem in that roll steer characteristics change due to changes in the tie rod attachment position with respect to the vehicle.

[Structure of the invention]

In this invention, a driving means for driving the gear housing is constructed of a hydraulic cylinder attached to the vehicle body side and surrounding the steering gear housing, and a piston provided integrally with the steering gear housing, and the gear housing is moved by the hydraulic cylinder. This made it possible.

〔Example〕

The present invention will be explained below based on the drawings. FIG. 1 is a diagram showing an embodiment of the present invention. First, to explain the configuration, the steering handle is connected to a pinion 13a of a steering gear 14 housed in a gear housing 17 via a steering shaft. A steering angle sensor 28 for detecting the steering angle of the steering wheel is attached to this steering shaft. The steering gear 14 housed in the gear housing 17 is of a rack-and-pinion type, and its rack 13 extends in the vehicle width direction, and both ends thereof are connected to the housing 1.
7 protrudes from both ends in the vehicle width direction so as to be displaceable in the axial direction. Both ends of the rack 13 are connected to steering wheels via ball joints and tie rods (steering cages), respectively.

The gear housing 17 is a substantially semi-cylindrical support body 2
3 and 23', the vehicle body 15 can be displaced in the vehicle width direction.
near the center of the supports 23, 23',
A piston 40 is attached which is fixed to the gear housing 17.

Hydraulic cylinder 4 wraps around this piston 40.
1 is fixed to the vehicle body by brackets 42, 42', and constitutes a hydraulic actuator.

Outer cylinder part of hydraulic cylinder 41 and gear housing 1
A steering angle sensor 30 is installed between the steering wheel and the steering wheel 7 to detect the relative displacement between the two and output it as a steering angle signal.

The hydraulic pump 50 is driven by an engine,
Oil is pumped up from the reservoir tank 51 and the oil pressure is maintained at a predetermined pressure by the action of the unload valve 52 and the accumulator 53.

The pressure oil is sent to the solenoid valve 55 through the filter 54, where the direction is controlled, and then the hydraulic oil is sent to the hydraulic cylinder 41.
is sent to the left and right chambers 56, 57 of the gear housing 1.
7 in the axial direction. Reference numeral 60 denotes a steering angle control device, which inputs the signal from the steering angle sensor 28 and the signal from the vehicle speed sensor 29, calculates the amount of movement (steering angle amount) of the gear housing 17, and outputs a control signal to the electromagnetic valve drive circuit 61. do. The steering angle device 60 is composed of a microcomputer unit and includes an interface circuit, an arithmetic processing circuit, and a storage device consisting of ROM and RAM.

The electromagnetic valve drive circuit 61 inputs a signal from the steering angle control device 60 and receives feedback from the steering angle sensor 30, which detects the relative displacement between the vehicle body 15 (or hydraulic cylinder 41) and the gear housing 17, through a displacement amplifier 62. The valve 55 is controlled to obtain the required steering angle (gear housing displacement).

When hydraulic pressure is applied to the oil chamber 56 of the hydraulic cylinder by the electromagnetic valve 55 (the oil chamber 57 side returns to the reservoir), the piston 40 integrally formed with the gear housing 17 only has pressure in the axial direction of the gear housing 17. A force is generated to press the gear housing 17 and secure the necessary amount of displacement. At this time, only an axial force is applied to the gear housing 17, and no moment is generated.

In this embodiment, the hydraulic cylinder 41 is connected to the bracket 4.
It is fixed directly to the vehicle body by 2,42',
By installing an elastic body between the hydraulic cylinder 41 and the brackets 42, 42' or between the brackets 42, 42' and the vehicle body, it is possible to prevent vibrations entering from the wheel side from being directly transmitted to the vehicle body. In this case, the steering angle sensor 30 must be directly attached to the vehicle body to eliminate expansion and contraction of the elastic body.

〔effect〕

As explained above, according to this invention,
The drive means for the gear housing is composed of a hydraulic cylinder that is attached to the vehicle body and surrounds the steering gear housing, and a piston that is integrally provided with the steering gear housing,
Since the gear housing is movable by the hydraulic cylinder, the gear housing driving force does not generate a moment that tilts the rack housing with respect to the gear housing axis, and the increase in friction of the support body due to vertical displacement of the gear housing is prevented. This has the effect of preventing changes in roll steer characteristics due to changes in the tie rod mounting position.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing an embodiment of the present invention. 17... Gear housing, 23, 23'... Support body, 28... Steering angle sensor, 29... Vehicle speed sensor, 30... Steering angle sensor, 40... Piston, 4
1... Cylinder, 55... Solenoid valve, 60... Rudder angle control device, 61... Solenoid valve drive device.

Claims (1)

[Scope of Claims] 1. A steering device that transmits a steering input applied to a steering wheel to steering wheels via a steering gear and a steering linkage; a drive means that adjusts the position of a housing of the steering gear; and a steering gear. In the steering device, the steering device has a support means for supporting the housing by allowing displacement of the housing, and a control means for driving the gear housing at a predetermined displacement amount or a predetermined displacement speed, wherein the driving means is attached to a vehicle body side and the steering gear housing is driven by the steering gear housing. A steering device comprising: a surrounding hydraulic cylinder; and a piston provided integrally with the steering gear housing, the gear housing being movable by the hydraulic cylinder.