JPH0353149B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in a vehicle steering system that steers front wheels and rear wheels by steering operation of a steering wheel.

The rotation required for steering the rear wheels is extracted from the front wheel steering system via the linkage member as rotation of the rotating member,
The eccentric pin of the joint member, which is loosely fitted and supported by the eccentric pin provided on the rotating member and which connects and supports the left and right rear wheel steering tie rods, swings horizontally and vertically as the crank rotates, causing the rotation angle to change in proportion to the steering angle. A steering device for a vehicle that simultaneously steers the front wheels and rear wheels by changing the steering ratio of the front and rear wheels.
No. 93394 (Japanese Unexamined Patent Publication No. 58-209657), etc.) was previously provided by the present 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 vehicle, the steering angle is increased during U-turns, entering/exiting operations in parking lots, etc. to obtain a small turning radius, resulting in good maneuverability of the vehicle.

However, the joint member that connects and supports the left and right rear wheel steering tie rods is supported by a loose fit on the eccentric pin, and is also located at the center of the lower rear part of the vehicle body. Since it swings left and right and up and down, it is inevitably subject to space constraints in the vertical direction, especially in the rear lower part of the vehicle body.

The present invention allows the inner ends of the tie rods for steering left and right rear wheels to horizontally swing only left and right without swinging up and down, which is advantageous in terms of space without being subject to vertical space constraints at the rear lower part of the vehicle body. It was created for the purpose of installing a rear wheel steering system.

In order to achieve such an object, the present invention provides an eccentric pin whose axis is offset in a rotating member that rotates in conjunction with a steering wheel and whose axis is directed in the front-rear direction, and the eccentric pin is provided with an eccentric pin whose axis is directed in the left-right direction. One end of a connecting rod is connected to the other end of the connecting rod, and an arm member that connects and supports left and right rear wheel steering tie rods and is pivoted on a vertical axis so as to be horizontally swingable is connected to the other end of this connecting rod. It is characterized by

A preferred embodiment of the present invention will be described in detail below with reference to the accompanying drawings. FIG. 1 is a perspective view showing a schematic configuration of a four-wheeled vehicle equipped with a steering device according to the present invention;
FIG. 2 is a plan view of the same, and FIG. 3 is an enlarged perspective view of the main parts.

The tip of the handle shaft 2 of the handle 1, which is the steering wheel, is incorporated into a rack-and-pinion type front wheel steering gear box 20 via a universal joint, etc.
As is known, a driven pinion (neither of which is shown in the figure) meshes with the left half of the rack that meshes with the drive pinion at the tip of the handle shaft 2 within the gearbox 20, and protrudes from the left and right sides of the gearbox 20, respectively. Tie rods 3, 3 are connected to both ends of the rack shaft 21. tie rod 3,3
The knuckle arms 4, 4 are connected to the outer ends of the knuckle arms 4, 4, and the front wheels 6.6 are supported by axles 5, 5 which protrude outward from the knuckle arms 4, 4.

The steering of the front wheels is achieved by steering the handle 1. That is, the rotation of the handle shaft 2 causes the rack shaft 21 to move left and right with respect to the gearbox 20 through the engagement of the pinion and the rack. moves left and right, and the Natsukuru arm 4,
4 rotates in the left-right direction, and the front wheels 6.6 are steered.

On the other hand, the rear part of the pinion shaft 22 of the driven pinion that meshes with the left half of the rack shaft 21 is led out rearward from the gearbox 20, and connected to a long linkage shaft 24 via a universal joint 23. An input shaft 31 is connected to the input shaft 31 via a universal joint 25.

The input shaft 31 is a rotating member disposed on the left side of the rear of the vehicle body and supported by a bearing bracket 32, and an eccentric pin 34 is provided protruding from the rear surface of a crank arm 33 fixedly integrated with the rear end.

The arm member 41 is arranged so as to be parallel to the input shaft 31 and coincide with the left-right center line C of the vehicle body at a neutral position for steering the rear wheels.

The arm member 41 is also pivoted at the front part on a vertical shaft 42, so that the arm member 41 is horizontally swingable.
Left and right rear wheel steering tie rods 13, 13 are connected and supported on the rear upper surface of the arm member 41 via ball joints 43, 43, respectively, and a pin 44 is formed to hang down from the rear lower surface of the arm member 41, and an eccentric shaft provided on the input shaft 31 is connected and supported. The pin 34 is connected to the pin 34 by a connecting rod 51 via each ball joint 35, 45. In this case, the eccentric pin 34 is initially set to be located vertically above the input shaft 31 in the neutral position.

Rear wheels 16, 16 are supported by axles 15, 15 which protrude outward from knuckle arms 14, 14 connected to the outer ends of tie rods 13, 13.
Further, the vertical shaft 42 is fixed to a bracket 46 fixedly supported on the vehicle body side.

When the steering wheel 1 is operated, the rack shaft 21 of the front wheel steering gear box 20 moves left and right.
The rotation necessary for steering the rear wheels is output to the driven pinion shaft 21 which meshes with the left half of the pinion shaft and rotates left and right, and the rotation is inputted to the input shaft 31 of the rear wheel steering system via the linkage shaft 24. The shaft 31 rotates either left or right.

By the way, for example, a driven pinion shaft 22 is attached to the rack shaft 21 of the front wheel steering gear box 20 from below.
If the input shaft 31 and the handle shaft 2 are related to each other, or if they are related from above and an idle gear is interposed between the two 21 and 22, the input shaft 31 will rotate in the opposite direction to the handle shaft 2.

As the input shaft 31 rotates, the connecting rod 51 connected to the eccentric pin 34 protruding from the rear end via the crank arm 33 connects the rear part of the arm member 41 supported at its right end with the crank rotation of the eccentric pin 34. It is caused to swing left and right horizontally around the vertical axis 42.

The left and right rear wheel steering tie rods 13, 13 are connected and supported by the arm member 41 by horizontal swinging of the arm member 41 to the left and right around the vertical axis 42.
is moved left and right, and the rear wheels 16, 16 are steered with a predetermined steering angle function as follows.

That is, first, from the neutral position of the eccentric pin 34 to 1/4 rotation, the rear part of the arm member 41 horizontally swings in the intended direction at a gradually decreasing speed via the connecting rod 51, and thus the tie rods 13, 13
The rear wheels 16, 16 supported by knuckle arms 14, 14 connected to the outer ends of the wheels are steered in the same direction as the front wheels. Next, from 1/4 rotation to 1/2 rotation of the eccentric pin 34, the rear part of the arm member 41 horizontally swings at a speed that gradually increases in the opposite direction to the above, and the rear wheel is still steered in the same direction as the front wheel. be done. Furthermore, from 1/2 rotation to 3/4 rotation of the eccentric pin 34, the rear part of the arm member 41 continues to swing in the opposite direction at a gradually decreasing speed.
The rear wheels are thus steered in the opposite direction to the front wheels.

As described above, the arm member 41 is connected to the vertical shaft 42.
Since it is configured to be pivoted to horizontally swing only, there is no restriction in vertical space at the rear lower part of the vehicle body.

As is clear from the above description, according to the present invention,
An eccentric pin with an offset axis is provided on a rotating member whose axis is oriented in the longitudinal direction and rotates in conjunction with the steering wheel, and one end of a connecting rod whose axis is oriented in the left-right direction is connected to this eccentric pin, An arm member that connects and supports left and right rear wheel steering tie rods and is pivoted on a vertical axis so as to be horizontally swingable is connected to the other end of this connecting rod, so that the inner ends of the left and right rear wheel steering tie rods are It is possible to horizontally swing only to the left and right without swinging up and down, making it possible to arrange the rear wheel steering system advantageously in terms of space without being constrained by vertical space at the rear lower part of the vehicle body. .

[Brief explanation of drawings]

The drawings show one embodiment of the present invention, and FIG. 1 is a perspective view showing a schematic configuration of a four-wheeled vehicle equipped with a steering device according to the present invention, FIG. 2 is a plan view of the same, and FIG. is an enlarged perspective view of the same main part. In the drawing, 1 is a steering wheel, 6 is a front wheel, 13 is a tie rod for rear wheel steering, 16 is a rear wheel, 31 is a rotating member, 34 is an eccentric pin, 41 is an arm member, 42 is its vertical axis, and 51 is a connectin. It's gross.

Claims (1)

[Scope of Claims] 1. In a vehicle steering device in which the rear wheels are steered together with the front wheels by the steering operation of the steered wheels, the axis of rotation in conjunction with the steered wheels is oriented in the longitudinal direction. An eccentric pin with an offset is provided, and one end of a connecting rod whose axis is oriented in the left-right direction is connected to this eccentric pin, and tie rods for steering left and right rear wheels are connected and supported to the other end of this connecting rod. A steering device for a vehicle, characterized in that an arm member pivotally supported on a vertical axis so as to be horizontally swingable is connected to the arm member.