JPS5975869A - Steering apparatus for car - Google Patents

Abstract

PURPOSE:To obtain the max. steering amount in the same phase and that in the reverse phase in a rear wheel steering angle which are different each other by installing a pinion and an eccentric pin onto a rotary member which revolves in interlock with a steering wheel. CONSTITUTION:Though a rear wheel 16 is steered at a positive acceleration in the same direction to a front wheel 6 until 1/4 revolution of an input shaft 31, the rear wheel is steered at a negative acceleration when 1/4 revolution is exceeded, and said rear wheel 16 is once returned to the neutral position between 1/4 revolution and 1/2 revolution, and the rear wheel 16 is steered in the reverse direction to the front wheel 6 until 3/4 revolution afterwards of the input shaft 31. The max. steering value y2 in the reverse phase of the rear wheel 16 is obtained when the input shaft 31 performs 3/4 revolution, and said max. value y2 is larger than the max. steering value y1 in the same phase in the case when the input shaft 31 performs 1/4 revolution, in other words, y2>y1.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a steering system for a vehicle in which front wheels and rear wheels are steered by steering operation of a steering wheel, and in particular, a rear wheel steering system is configured with a transmission mechanism such as a differential mechanism. The present invention relates to a steering device for a vehicle.

The rotation required for rear wheel steering is output from the front wheel steering system via the linkage member as rotation of a swing link or eccentric pin, etc., and the front and rear wheels are rotated so that the steering ratio of the front and rear wheels is changed in proportion to the steering angle. Vehicle steering device that steers wheels and wheels at the same time (patent application 1982-
No. 118698, Japanese Patent Application No. 57-47743, etc.) were 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 in the vehicle, when making U-turns or maneuvering people in a parking lot, the steering angle is set to a dog position to obtain a small turning radius, resulting in good maneuverability of the vehicle.

However, the steering of the rear wheels has been accomplished using a steering angle function consisting of a single function of rotation of the swing link, eccentric bin, etc.

Also, since the rear wheel turning angle relative to the steering angle is represented by a sine wave,
The maximum steering amount in the same phase and the maximum steering amount in the opposite phase were equal.

The present invention steers the rear wheels using a complex steering angle function made up of the sum of a plurality of functions, and also makes the maximum steering amount for the same phase and the maximum steering amount for the opposite phase of the rear wheel steering angle different. In order to achieve this purpose, the present invention provides an arm that connects and supports left and right rear wheel steering tie rods by providing a pinion and an eccentric pin on a rotating member that rotates in conjunction with a steering wheel. The member is configured to be pivoted at two points by a rack shaft that meshes with the pinion and a connecting rod that has one end connected to an eccentric pin.

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, and Fig. 2 is a plan view of the main transmission mechanism, showing the 0 part of the rotating member as viewed from 90° rotation. It is a diagram.

The tip of the handle shaft 2 of the handle 1, which is a steered wheel, is incorporated into a rack-and-pinion type front wheel steering gear box 20, and meshes with a drive pinion at the tip of the handle shaft 2 within the gear box 20, as is known. On the left half of the rack is a driven pinion (both not shown in the diagram).

) mesh with each other, and tie rods 3, 3 are connected to both ends of a rack shaft 21 that protrudes from the left and right sides of the gear box 20, respectively. A knuckle arm 4 is attached to the outer end of the tie rods 3, 3.
, 4 are connected, and the front wheels 6, 6 are connected to the knuckle arm 4.
, 4 are supported by axles 5, 5 which protrude outward.

The front wheels are steered by steering the handle 1. In other words, the rotation of the handle shaft 2 causes the rack shaft 21 to move left and right with respect to the gear box 20 through the engagement of the rack and the shift pinion. Both tie rods 3, 3 move left and right,
Knuckle arm 4.・4 rotates in the left and right direction and the front wheel 6,
6 is 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 gear box 20, and connected to a long linkage shaft 24 via a universal joint 23. An input shaft 31 is connected to the end via a universal joint 25.

The input shaft 31 is a rotating member incorporated in a rear wheel steering gear box 30 located on the left side of the rear of the vehicle. A crank arm 33 is fixed to the rear end of the input shaft 31 that protrudes rearward of the gear box 3o, and an eccentric pin (not shown) is protruded from the rear surface of the crank arm 33. ing.

Then, the rack 3 is mounted on the pinion 32 orthogonally to the input shaft 31.
At the same time, a connecting rod 37 is connected to the crank pin via a ball joint 36, and the rack shaft 35
and the connecting rod 37 are arranged substantially parallel to each other.

A rack shaft 35 is largely projected to the right of the gear box 30, and the front end of an arm member 41 is pivoted to the right end of the rack shaft 35 by a pin 38 so as to be horizontally swingable. This arm member 41 is arranged to coincide with the left-right center line of the vehicle at the neutral position for steering the rear wheels.

Further, at the right end of the connecting rod 37, the intermediate portion of the arm member 41 is pivoted via a ball joint 39 so as to be horizontally swingable. In this case, the crank pin is initially set to be located vertically above the input shaft 31 in the neutral position.

Left and right tie rods 13.degree. 13 are connected and supported via ball joints 42.42, respectively, to the rear end of the arm member 41 which is pivotally supported at two points 38.39 spaced apart in the front and back.

Rear wheels 16, 16 are supported on outwardly projecting axles 15, 15 of knuckle arms 14, 14 connected to the outer ends of tie rods 13, 13.

Note that both gear boxes 20 and 30 are fixed to the vehicle body side.

When the steering wheel 1 is operated, the rack shaft 21 of the gear box 20 for steering the front wheels moves left and right, and the driven pinion shaft 22, which meshes with the left half of the rack shaft 21 and rotates left and right, receives the rotation necessary for steering the rear wheels. is output, and the above rotation is input to the input shaft 31 of the rear wheel steering system via the linkage shaft 24, so that the input shaft 31 rotates to either the left or right.

A rack shaft 35 meshes with a pinion 32 fixed to the front outer periphery of the input shaft 31 as it rotates, and a connecting rod 3γ connected to a crank pin protruding from the rear end via a crank arm 33. , move linearly to either the left or right at relatively different speeds, and the connecting rod 37 moves linearly back and forth in one direction as the crank pin rotates.

First, the rack shaft 3 is formed by meshing the binion 32 and the rack 34.
5 is proportional υ, and when the arm member 41 pivoted on the right end of the rack shaft 35 uses the rear pivot point 39 as an immovable fulcrum, the left and right tie rods 13 connected and supported at the rear end of the arm member 41 After lateral movement of 13 degrees, the rear wheel 16.
16 is horizontally swung so as to be steered in a linear shape as shown in the straight line A in FIG.

On the other hand, when the front pivot point 38 is set as an immovable fulcrum, the arm member 41 pivoted to the right end of the connecting rod 37 whose left end is pivoted to the crank pin rotates the rear wheel as shown in the sinusoidal curved opening in FIG. It swings horizontally as if steering.

Here, the positive and negative input coordinates in FIG. 4 represent right and left steering of the steering wheel 1, respectively, and the positive and negative output coordinates represent right and left steering of the rear wheel 16, respectively. First, if the driven pinion shaft 22 is related to the rack shaft 21 of the front wheel steering gear box 20 from below, or if it is related from above and an idle gear is interposed between both 21 and 22, the input shaft 31 can be connected to the steering wheel. It can be seen that the rack shaft 35 of the rear wheel steering gear box 30 also moves forward and backward in the same direction as the shaft 2 rotates in the opposite direction. However, the connecting rod 37 performs a linear motion in the same direction as the rack shaft 35 while gradually decreasing the speed from the neutral position of the crank pin to 1/4 rotation, but gradually increases the speed from 1/4 rotation to 1/2 rotation. While doing so, it performs a linear motion in the opposite direction, and also performs a linear motion in the opposite direction from 1/2 rotation to 3/4 rotation while gradually decreasing the speed. Therefore, if the rear pivot point 39 is the immovable fulcrum, the front pivot point 38 moves approximately linearly in either the left or right direction at a constant speed, and therefore the arm member 4
1 moves linearly in the opposite direction to the front pivot point 38 in an equal continuous path. If the fixed fulcrum is the front pivot point 38, the rear pivot point 39 gradually decreases in the same direction as the front pivot point 38 until 1/4 rotation of the input shaft 31, and from 1/4 rotation to 1 rotation. /
Up to 2 rotations, the speed gradually increases in the opposite direction, and from 1/2 rotation to 3/4 rotation, the speed gradually decreases in the opposite direction, and each movement is approximately linear. Therefore, in this case, the rear end of the arm member 41 moves substantially linearly in the same direction as the rear pivot point 39 at a variable speed responsive to each state.

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, and FIG. 2 shows a rotating member portion rotated by 90 degrees in a parent state. A plan view of the main transmission mechanism shown in Figure 3 is 3-3 in Figure 2.
A line sectional view, FIG. 4 is an input-output diagram of rear wheel steering, and FIG. 5 is a locus diagram of the arm member.

In the drawings, 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, 32 is a binion, 35 is a rack shaft, 37 is a connecting rod, 41 is an arm member, A is an eccentric bin.

Patent applicant Honda Motor Co., Ltd. agent Patent attorney 2 1) Yong - Immediate question Patent attorney Kuni Ohashi Production volume Patent attorney 2
Yama Yu Figure 2 Figure 3 Figure 4 rgJ Figure 5

Claims (1)

[Claims] In a vehicle steering system in which the front wheels and the rear wheels are steered by steering operation of the steering wheel, a rotating member that rotates in conjunction with the steering wheel is provided with a pinion and an eccentric pin, and a rack shaft that meshes with the pinion and an eccentric pin are provided. A vehicle steering system comprising an arm member that connects and supports left and right rear wheel steering tie rods and is pivoted at two points by a connecting rod whose one end is connected to a bin.