JPH1053148A - Power steering device for automobile - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent lowering of strength and increase of steering torque caused by repeated bending or the like of an inner cable by constituting a drum in such a way as to be rotated integrally with a rotary shaft of the drum and to move axially by winding and rewinding the inner cable. SOLUTION: A steering wheel is rotated in one direction to wind one of two inner cables, wound around a steering wheel side drum 7 and a steering position side drum 7, onto the steering wheel side drum 7 and to deliver the inner cable 6 from the steering position side drum 7 so as to rotate the drum 7 and a rotary shaft 8 in one direction. At this time, the other inner cable 6 is delivered from the steering wheel side drum 7 and wound onto the steering position side drum 7. The drum 7 is thus moved vertically by the action of a ball screw A by winding and delivering the inner cable 6, and pressing or the like to the inner edge of a cylindrical fixture 3 can be eliminated by keeping winding and delivery positions constant.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power steering apparatus for an automobile using two control cables and a power cylinder which apply a pulling force to an inner cable, and in particular, the inner cable has a reduced strength due to repeated bending. The present invention relates to a power steering device for an automobile, which prevents the steering torque from increasing and prevents the steering torque from increasing.

[0002]

2. Description of the Related Art The applicant of the present application discloses a power cylinder having a piston rod connected to a front wheel via a steering link mechanism at both ends, and is supplied to the power cylinder and simultaneously discharged from the power cylinder. A rotary control valve for controlling the direction of pressurized oil, a valve-side drum connected to the rotor of the control valve, a handle-side drum connected to the handle, and a freely sliding inside the flexible outer tube. Patent application for a power steering device for an automobile including: two control cables wound around spiral grooves of both drums so that the inserted inner cable exerts a tensile force alternately when the handle-side drum rotates in an alternate direction. And
It was published as JP-A-8-2431.

[0003]

However, in the invention described in the above publication, the drum is fixed to its rotating shaft, so that when the drum rotates, the inner cable moves in the axial direction along the spiral groove. I do
Since the inner cable enters the case from the cylindrical fixing device fixed to the case and is wound around the drum, the inner cable swings around the inner end of the cylindrical fixing device by the axial movement by the spiral groove. As a result, the bending may be repeated, or it may be strongly rubbed against the tubular fixing device to reduce the strength, or the frictional force may increase the steering torque.

To reduce the swing angle of the inner cable, the distance between the end of the cylindrical fixture and the drum may be increased, but this would make the case large and difficult to fit in a narrow engine room. Become.

[0005]

According to the present invention, as a means for solving such a problem, a drum is integrally rotated with respect to each rotation shaft of the drum, and an inner cable is provided. The drum moves in the axial direction with the winding and rewinding of the inner cable, so that the inner cable itself hardly bends, and the strength is reduced and the steering torque is reduced. Has the effect of preventing an increase in

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the accompanying drawings.

In FIG. 1, reference numeral 1 denotes a handle, which is rotatably supported by a case 2 attached to a vehicle body.

[0008] In the steering position in front of the vehicle body, the case 2
A case 2 having the same structure as that described above is disposed between the two cases 2 and 2, and two flexible control cables in which the end of the outer tube 5 is fixed to the cases 2 and 2 by the cylindrical fixture 3. 4 are routed.

The control cable 4 is a cable in which an inner cable 6 is slidably inserted into an outer tube 5. As shown in FIG. 2, a cylindrical fixing member 3 is crimped to the end of the outer tube 5. A male screw 11 formed on the outer periphery of the control cable 4 is screwed into a nut 12 fixed to the case 2. The inner cable 6 is a spiral groove 7a of a drum 7 rotatably supported in the case 2.
As shown in FIGS. 5 and 6, the winding directions of the two inner cables 6 are opposite to each other, and the terminals 6 a are fixed to both end faces of the drum 7.

A rotating shaft 8 of the drum 7 protrudes from one surface of the case 2, and is connected to the rotating shaft of the handle 1 on the handle 1 side and a rotary valve 9 described later on the steering position side.
, Respectively.

In FIG. 1, reference numeral 14 denotes a cylinder tube 1
5. A power cylinder in which a piston 16 is slidably fitted to a piston rod 5, and a piston rod 17 fixed to the piston 16.
A tie rod 20 is connected to both ends via ball joints 19, and the tie rod 20 is connected to a front wheel a via a knuckle arm (not shown).

In the present invention, the tie rod 20, the knuckle arm and the like are collectively referred to as a steering link mechanism.

A pinion 21 is fixed to the rotor 10 of the rotary valve 9 and meshes with the rack 18.

The supply port 22 of the rotary valve 9 is connected to a hydraulic pump (not shown), and the discharge port 23 is connected to a tank (not shown).
The pipes 4 and 25 are connected to two ports 26 and 27 of the cylinder tube 15 by pipes 28 and 29. When the rotor 10 rotates in one direction, pressure oil is supplied to one side of the piston 16 and discharged from the other side. When rotated in the other direction, the pressure oil is supplied to the other side of the piston 16 and is discharged from one side, so that the piston 16 operates together with the piston rod 17.

What has been described above is the known structure described in the above-mentioned publication and operates as follows.

When the handle 1 is rotated in one direction, the inner cable 6 of the two control cables 4 wound around the drum 7 on the handle 1 and the drum 7 on the steering position side
Is wound on the drum 7 on the handle 1 side, the inner cable 6 is fed out from the drum 7 on the steering position side, and the drum 7 and the rotating shaft 8 rotate in one direction.

At this time, the other control cable 4
Is pulled out from the drum 7 on the handle 1 side and wound up on the drum 7 on the steering position side.

When the handle 1 is rotated in the other direction, the drum 7 on the steering position side and its rotating shaft 8 rotate in the other direction by the same operation.

When the rotating shaft 8 of the drum 7 at the steering position rotates in one direction, the rotor 10 connected thereto rotates in the same direction, and the engagement between the pinion 21 and the rack 18 causes the piston rod 17 to move in one direction. At this time, the rotation of the rotor 10 causes the rotary valve 9 to rotate.
Pressure oil is supplied from one of the ports 24, 25 to one of the ports 26, 27 of the power cylinder 14, the piston rod 17 operates in the same direction as described above, and the wheel a faces one via the steering link mechanism. .

When the rotating shaft 8 of the drum 7 at the steering position rotates in the other direction, the wheel a faces the other by the same operation.

In the present embodiment, as shown in FIGS. 2, 3, and 4, the rotating shaft 8 has a disk 30 integrally formed at the end thereof, and three protrusions 31 are formed on the disk 30. They are integrally formed at intervals and protrude into the case 2, and are tightly and slidably fitted into insertion holes 32 formed at equal intervals around the rotation center of the drum 7.

A ball groove 33 is formed at the center of rotation of the drum 7 in a spiral shape having the same pitch as the spiral groove 7a on the outer periphery of the drum 7, and a spiral ball groove 35 having the same pitch as described above is formed at the center. The formed screw rod 34 is the case 2
Are fixed so that they cannot move and rotate.
A number of balls 36 are filled between 3 and 35 to form a ball screw A.

The rotation mechanism of the drum 7 in the present embodiment has the above-described structure. When the rotation shaft 8 is driven to rotate on the handle 1 side, the drum 7 rotates in one direction due to the fitting of the projection 31 and the insertion hole 32. One inner cable 6 is wound around the spiral groove 7a of the drum 7, and the other inner cable 6 is unwound from the spiral groove 7a, so that the winding and unwinding positions with respect to the drum 7 change up and down. However, since the drum 7 moves up and down by the action of the ball screw A, and the pitch of the ball screw A and the pitch of the spiral groove 7a are the same, the winding and unwinding positions of the inner cable 6 with respect to the case 2 are almost constant. Therefore, the strength is reduced by being pressed or rubbed against the inner edge of the cylindrical fixing member 3, and the steering torque is prevented from increasing due to frictional force. , And the at steering position side of,
The rotating shaft 8 rotates in the alternate direction together with the drum 7 due to the pulling of the two inner cables 6 in the alternate direction to rotate the rotor 10 of the rotary valve 9. As a result, the drum 7 moves up and down so that the winding and unwinding positions are kept substantially constant, and the drum 7 is not pressed or rubbed against the inner edge of the cylindrical fixture 3.

In the present embodiment, the drum 7 is moved up and down with the winding and unwinding of the inner cable 6 by the ball screw A.
A male screw and a female screw having the same pitch may be fitted to each other. Further, the drum 7 is rotatably and slidably fitted on a fixed shaft, and the inner cable 6 is wound around the spiral groove 7a and fed out, so that the drum 7 is wound. You may make it move up and down.

[Brief description of the drawings]

FIG. 1 is a partially cutaway perspective view showing an outline of an embodiment of the present invention.

FIG. 2 is a perspective view of a main part of the present invention.

FIG. 3 is a sectional view of the same.

FIG. 4 is an exploded perspective view thereof.

FIG. 5 is a perspective view showing a state in which one inner cable is wound around a drum.

FIG. 6 is a perspective view showing a state in which the other inner cable is wound around a drum.

[Description of Signs] 1: Handle 2: Case 3: Cylindrical fixing tool 4: Control cable 5: Outer tube 6: Inner cable 7: Drum 7a: Spiral groove 8: Rotating shaft 9: Control valve 10: Rotor 14: Power Cylinder 17: Piston rod 31: Projection piece 32: Insertion hole 33, 35: Ball groove 34: Screw rod A: Ball screw

Claims (4)

[Claims] 1. A power cylinder having a piston rod connected at both ends to a front wheel via a steering link mechanism, and a direction control of pressure oil supplied to the power cylinder and simultaneously discharged from the power cylinder. A rotary control valve, a valve-side drum connected to a rotary shaft of a rotor of the control valve, a handle-side drum connected to a rotary shaft of a handle, and a slide-free inside a flexible outer tube. And two control cables wound around the spiral grooves of the two drums so that the inserted inner cable exerts a tensile force alternately upon rotation of the handle-side drum in an alternate direction. The respective drums rotate integrally with the respective rotation shafts of the respective drums, and An automotive power steering device that moves in the axial direction as the cable is wound and unwound. 2. The power steering apparatus for an automobile according to claim 1, wherein each of the drums is slidably fitted to each of the rotating shafts. 3. The power steering apparatus for an automobile according to claim 1, wherein each of the drums and each of the rotating shafts are fitted with male and female screws having the same pitch as the spiral grooves. 4. The power steering apparatus for an automobile according to claim 1, wherein each of the drums and each of the rotating shafts are fitted with a ball screw having the same pitch as the spiral groove.