JPH0356947B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in a steering system for a vehicle that steers the rear wheels together with the front wheels, and particularly relates to the assembly structure of a joint member portion that connects and supports left and right rear wheel steering tie rods. .

A driven pinion is engaged with the rack shaft of a rack pinion type steering gear that constitutes the main part of the front wheel steering system, and the input shaft connected to the driven pinion via a linkage shaft receives the rotation necessary for steering the rear wheels. The steering angle is determined by the horizontal and vertical rocking of the eccentric pin of the joint member, which is loosely fitted and supported by the eccentric pin provided on the input shaft of the steering system and which connects and supports the left and right rear wheel steering tie rods. A steering system for a vehicle that steers the front wheels and rear wheels simultaneously so as to change the steering ratio of the front and rear wheels in proportion to
No. 209657) etc.) were previously provided by the applicant.

According to such a steering device, it is possible to steer the rear wheels in the same direction as the front wheels by operating a small steering angle of the steered wheels, and it is also possible to steer the rear wheels in the opposite direction by operating a large steering angle, thus making it possible to drive at high speed. In addition to improving maneuverability inside the U
When making turns or maneuvering in and out of a parking lot, the steering angle is increased to obtain a smaller turning radius, which improves maneuverability of the vehicle.

The joint member is fixedly supported by the other end of a link arm member whose one end is pivotally supported on the vehicle body side, and this restricts the swinging of the joint member in the rotational direction due to the crank rotation of the eccentric pin, and the joint member is held in a horizontal state. is retained.

By the way, in the above-mentioned steering device, the joint member is configured to have a substantially inverted T-shape from the front.
The eccentric pin is loosely fitted into the upper part of the vertical rod part, and the link arm member is tied to the rear surface of the horizontal rod part below the vertical rod part, and the The left and right rear wheel steering tie rods were connected.

However, since the part where such a joint member is installed is below the floor panel of the vehicle body, it is inevitably constrained in the vertical direction, so the vertical height of the joint member must be lowered, and furthermore, the link arm member and rear It is desired that the joint member portion be made more compact by devising the connection and pivoting of the tie rod for wheel steering to the joint member.

The present invention has been made in response to the above-mentioned needs, and its purpose is to reduce the vertical height of the joint member portion in the assembled state to achieve compactness, which is advantageous in terms of layout. The present invention provides a steering device for a vehicle.

In order to achieve such an object, the present invention provides a joint member that is loosely fitted and supported by an eccentric pin that is provided with an offset axis on an input shaft whose axis is oriented in the front-rear direction. The main feature is that tie rods for steering the rear wheels are pivotally connected to both sides of the shaft, and link arm members for regulating swing are connected in correspondence with the axial center position of the eccentric pin.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A preferred embodiment of the present invention will be described in detail below along with the configuration of a front and rear wheel steering system for a vehicle. FIG. 1 is a perspective view showing a schematic configuration of a front and rear wheel steering system, FIG. 2 is an exploded perspective view of the main parts of the rear wheel steering system, and FIG. 3 is a sectional view of the main parts in an assembled state.

A pinion shaft 21 is connected to the lower end of the handle shaft 2 of the steering wheel 1 through a universal joint 3, and the lower part of the pinion shaft 21 is connected to a gear box 2 of a rack-pinion type steering gear for steering the front wheels.
A drive pinion (not shown) meshes with a rack 24 formed in the right half of the rack shaft 23. This rack 24 is formed so as to face upward and forward.

A cylinder barrel 29 is installed horizontally in the gearbox 20, and the rack shaft 23, which is a piston rod that slides inside the cylinder barrel 29, and the cylinder barrel 29 constitute a power cylinder as is known in the art. A rack 25 is also formed in the left half on the left side of the power cylinder, and a driven pinion 26 is meshed with the rack 25. This rack 25 is formed so as to face upward.

By the way, the upper part of the shaft 21 of the drive pinion is tilted backward and slightly to the right, and the shaft 27 of the driven pinion 26 is arranged approximately horizontally in the front-rear direction, but the rear part is tilted slightly to the right. The teeth of both the pinion and the racks that mesh with each other are helical teeth.

Tie rods 4, 4 are connected to both ends of a rack shaft 23 protruding from the left and right ends of the gearbox 20, respectively, and knuckle arms 5, 5 are connected to the outer ends of the tie rods 4, 4, and the front wheels 7, 7 are connected to the knuckle arms. Axles 6, 6 protruding outward from 5, 5
is supported by

As is known, the front wheels are steered by the left and right movement of the rack shaft 23, and at this time the steering torque is reduced by the power cylinder.

On the other hand, the rear part of the shaft 27 of the driven pinion 26 protrudes rearward from the gearbox 20 and connects to the universal joint 3.
A long linkage shaft 32 is connected approximately linearly through a universal joint 3 at the rear end of the linkage shaft 32.
An input shaft 40 is connected via 3.

The input shaft 40 is arranged in alignment with the left-right center line of the vehicle, and includes a holder 47, a plurality of ring rubbers 48 (in the figure, five wheels) attached to the outer periphery of the holder 47, and further attached to the outer periphery of the ring rubber 48 to the floor panel of the vehicle body. It is a rotating member supported by a fixed holder outer 49, and an eccentric flange 41 is provided at the rear end of this input shaft 40.
is formed.

An eccentric pin 42 protruding further rearward is formed on the rear surface of the eccentric flange 41, and a joint member 50 is loosely fitted and supported at the center of the eccentric pin 42.

The joint member 50 is short in the vertical direction and long in the horizontal direction.
The inner ends of left and right tie rods 8, 8 are connected and supported via ball joints 9, 9 to the left and right ends of the front surface 51 of 0, respectively, and the tip of an arm member 61 is connected to two left and right ends near the center of the rear surface 51. They are connected by bolt connections 62, 62. The base of the arm member 61 extends to the right in a substantially horizontal manner, and the arm member 61 is swingably supported by a link 63 that is pivotally supported by a link bracket 64 hanging from the floor panel of the vehicle body. As a result, the joint member 50
is kept in a horizontal state and its swinging is restricted.

Further, knuckle arms 11, 11 are connected to the outer ends of the left and right tie rods 8, 8, which are connected and supported by the joint member 50.
The rear wheel 1 is mounted on the axle 12, 12 which protrudes outward from the wheel 1.
3,13 are supported.

In the figure, 14 is a damper unit for the front wheel, 15 is the same radius slot, and 16 is the same lower arm.
Further, 17 is a damper unit for the rear wheel, 18 is the same radius slot, and 19 is the same lower arm.

When the steering wheel 1 is operated, the left-right movement of the rack shaft 23 of the steering gear outputs the rotation necessary for steering the rear wheels to the driven pinion 26 that meshes with the rack 25 on the left half of the steering gear, and the rotation required for steering the rear wheels is output to the driven pinion 26 that meshes with the rack 25 on the left half of the rack shaft 23 of the steering gear.
The above rotation is input to the input shaft 40 of the rear wheel steering system through the input shaft 2, and the input shaft 40 rotates to either the left or right.

As the input shaft 40 rotates, the eccentric pin 42 provided integrally at the rear end performs crank rotation, and is rotated in a direction perpendicular to the input shaft 40 (vertically upward in the embodiment).
With the crank rotation of this eccentric pin 42, which is initially set to , the joint member 50, tie rod 8,
8. Rear wheel 13 via the nutkl arms 11, 11,
13 is steered.

That is, at a small steering angle of 1/2 rotation from the initial neutral position of the eccentric pin 42, the rear wheel 13 is in the same phase as the front wheel 8,
At a large steering angle exceeding 1/2 rotation, the steering will be in the opposite phase.

Next, the configuration of the joint member 50 and the assembly configuration with the eccentric pin 42, the arm member 61, and the rear wheel steering tie rods 8, 8 will be described in detail.

As shown in the figure, the joint member 50 has a symmetrical shape that is low in vertical height and long in the left and right direction, has a certain thickness in the front and back direction, and has a cylindrical part 53 protruding forward in the center of the front face 51. A hole 55 having a large diameter is formed concentrically from the rear part of the cylindrical part 53 to the rear surface 52.

Tapered mounting holes 56, 56 for fitting the ball joints 9, 9 are formed at both left and right ends of the front surface 51 of the joint member 50, and holes 56 are formed on the left and right sides of the rear surface 52 from the hole 55. Female screw part 57, 57
is drilled.

The axes of the cylindrical portion 53, the left and right mounting holes 56, 56, and the female screws 57, 57 are the joint member 50.
It coincides with the upper and lower center line l of .

On the other hand, the rear end of an eccentric pin 42 that is rotatably supported by a holder 47 and is integrated and protrudes from the rear end of an input shaft 40 that is elastically supported toward the vehicle body via a ring rubber 48 and a holder outer 49. A male threaded portion 43 having a small diameter is carved, and a flat surface 44 is formed in the male threaded portion 43 along the axial direction.

To attach the joint member 50 to the eccentric pin 42, first attach the eccentric flange 41 at the base of the eccentric pin 42.
A seal ring 71 is interposed between the outer circumference of the joint member 50 and the inner circumference of the enlarged diameter portion 54 of the cylindrical portion 53 of the joint member 50,
A needle bearing 72 is interposed between the outer periphery of the eccentric pin 42 and the inner periphery of the cylindrical portion 53, and a hole 55 at the rear of the cylindrical portion 53 is inserted.
The male screw portion 43 at the tip of the eccentric pin 42 is exposed inside.

After that, a washer 73 having a flat surface 74 formed on the inner periphery is fitted to the male threaded part 43, and then a lock nut 75 is fitted.
Screw on. At this time, the lock nut 75 is
It is buried inside.

The ball joints 9, 9 are fitted from the front into the mounting holes 56, 56 at the left and right ends of the joint member 50, which is loosely fitted and supported at the center by the eccentric pin 42, respectively. Connect the inner ends of the left and right rear wheel steering tie rods 8,8.

Then, the tip of the arm member 61 is superimposed on the rear surface 52 of the joint member 50, the hole 55 is closed, and female screw portions 57 are formed on the left and right sides near the center.
The arm member 61 is coupled to the joint member 50 by screwing the bolts 62, 62 into the joint member 57. At this time, the arm member 61 is pivotally supported by the link member 63 so that the front end faces the left and right center of the vehicle from the right side, and is bolted to the joint member 50 on the left and right sides, so the joint member 50 can be attached to the upper and lower sides. The arm member 61 and the left and right rear wheel steering tie rods 8, 8 are connected to the joint member 50 with the center line l parallel to the ground and at the same level H as the axis C of the eccentric pin 42. It will be pivoted and supported.

Thus, the vertical height of the joint member 50 is reduced, and the joint member 50 is divided into a front face 51 and a rear face 52, and rear wheel steering tie rods 8,
8 and the arm member 61 are connected, and the axis C of the eccentric pin 42 and the connecting portion of the arm member 61 and tie rods 8, 8 are assembled at approximately the same level H, so that the assembly of the joint member 50 portion is It is possible to achieve compactness by reducing the vertical height in the attached state. Therefore, it is very advantageous in terms of layout.

In the embodiment, the tie rods 8, 8 and the arm member 61 are connected to the front surface 51 and the rear surface 52 of the joint member 50, respectively, but of course, both the front surface 51 and the rear surface 52 are connected to the tie rods 8, 8 and the arm member 61, respectively.
It is also possible to connect to

As is clear from the above description, according to the present invention, the axial center position of the eccentric pin can be adjusted with respect to the joint member that is loosely fitted and supported by the eccentric pin that is provided with the axial center offset from the input shaft whose axis is oriented in the front-rear direction. Tie rods for steering the rear wheels are pivotally attached to both sides in the left and right direction, and a link arm member for regulating swing is tied to the axis position of the eccentric pin. The vertical height of the joint member in the assembled state can be lowered,
This part can be made more compact,
This is advantageous in terms of layout.

[Brief explanation of drawings]

The drawings show a preferred embodiment of the present invention, and FIG. 1 is a perspective view showing a schematic configuration of a front and rear wheel steering device;
Fig. 2 is an exploded perspective view of the main parts of the rear wheel steering system, Fig. 3 is a longitudinal side view of the main parts in the assembled state, showing the joint member rotated 90 degrees, and Fig. 4 is the steering gear. FIG. 3 is an exploded perspective view of the box portion. In the drawing, 8 is a tie rod for rear wheel steering, 40 is an input shaft, 42 is an eccentric pin, 50 is a joint member,
61 and 63 are link arm members.

Claims (1)

[Scope of Claims] 1. An eccentric pin whose axis is offset in the front-rear direction is provided on an input shaft that rotates in conjunction with the steered wheels, and tie rods for steering left and right rear wheels are connected and supported to this eccentric pin. A joint member is loosely fitted and supported, and this joint member is fixedly supported at the other end of a link arm member whose one end is pivotally supported on the vehicle body side. In the vehicle steering system, the vehicle steering device is configured to hold the joint member in a horizontal state while restricting the swinging of the joint member in the rotational direction due to crank rotation, and is configured to steer the rear wheels together with the front wheels. The rear wheel steering tie rods are pivotally attached to the joint member which is loosely fitted and supported by the eccentric pin on both sides in the left and right direction of the axial center position of the eccentric pin, and the tie rods are pivoted in positions corresponding to the axial center position of the eccentric pin. A steering device for a vehicle, characterized in that the link arm member is tied together.