JPH0353151B2 - - 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 necessary for steering the rear wheels is extracted from the front wheel steering system via a linkage member as rotation of an input shaft, and a rotating body such as a gear provided integrally with the input shaft and at least one other rotating body are connected to the input shaft. A steering system for a vehicle comprising a rotating body mechanism consisting of a rotating body mechanism, and in which tie rods for steering left and right rear wheels are pivotally supported eccentrically on separate rotating bodies (Japanese Patent Application No. 56-127189 (Japanese Unexamined Patent Publication No. 58-30870) Reference)) was previously provided by the applicant.

Such a steering system is initially set by pivoting the right and left rear wheel steering tie rods eccentrically on a vertical line of the end face of each rotary body, so a small steering angle operation of the steered wheels can turn the rear wheels into the front wheels. It is possible to steer in the same direction, and also to steer in the opposite direction by operating a large steering angle, which improves maneuverability during high-speed driving and makes it easier to perform U-turns, input operations in parking lots, etc. In this case, the steering angle can be increased to obtain a small turning radius, which improves the maneuverability of the vehicle.

By the way, it is known that the wheels on the outside of the turn have a greater influence on the steering response characteristics when a vehicle turns than the wheels on the inside of the turn.

The present invention has devised the above-mentioned steering device so that the maximum steering amount of the rear wheel on the outside of the turn in an opposite phase to the front wheel steering is made larger than the maximum steering amount in the same phase, and the steering device when the vehicle turns The shape of the steering angle function of the rear wheel on the outside of the turn, which greatly affects the response characteristics, is set to the ideal shape, while the shape of the steering angle function of the rear wheel on the inside of the turn differs from the ideal due to structural reasons. This was done with the aim of making the turning of the vehicle close to the ideal as a general effect.

In order to achieve such an object, the present invention provides that the left and right rear wheel steering tie rods are connected to an input shaft whose axis is directed in the front-back direction with respect to the end face of each rotary body connected to the input shaft with the axis directed in the longitudinal direction, at the neutral position of the steered wheels. It is characterized in that it is pivoted at a predetermined angle offset from the horizontal line connecting the individual axes in the vertical direction and outward in the left-right direction from the vertical line passing through the individual axes.

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 to which the present invention is applied, and FIG. 2 is a front view of a rotating body mechanism, which is a main part, as seen from the rear of the vehicle.

The tip of the handle shaft 2 of the handle 1, which is a steering wheel, is built into a rack-and-pinion type front wheel steering gearbox 20, and as is known, there is a rack in the gearbox 20 that meshes with a drive pinion at the tip of the handle shaft 2. A driven pinion (both not shown in the figure) meshes with another rack formed on the left side, and tie rods 3 are connected to both ends of a rack shaft 21 that protrudes from the left and right sides of the gearbox 20, respectively. There is. Knuckle arms 4, 4 are connected to the outer ends of the tie rods 3, 3, and 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 the universal joint 23.
A long linkage shaft 24 is connected to the rear end of the linkage shaft 24 through a universal joint 25, and an input shaft 31 is connected to the rear end of the linkage shaft 24.

The input shaft 31 is a rotating member disposed to the left of the left-right center line of the vehicle and supported by a bearing bracket 32. A drive gear 33, which is a rotating body, is fixedly integrated with the rear end of the input shaft 31. ing.

Drive gear 33 includes driven gear 3 from the right side.
4 mesh at a gear ratio of 1, the driven gear shaft 35 is disposed to the right of the left-right center line of the vehicle, and is supported by the bearing bracket 32 in parallel with the input shaft 31.

The inner ends of left and right rear wheel steering tie rods 13, 13 are pivotally supported on the rear end surfaces of both gears 33, 34, respectively, as shown in FIG.

First, the axis o ₁ of the drive gear 33 and the drive gear 3
The perpendicular lines of the gears 33 and ₃₄ , respectively, with respect to the horizontal line H connecting the axis o2 of the gears 4 and 4 are defined as Nl and Nr.

In the illustrated state, the handle 1 is in a neutral position, and therefore the gears 33 and 34 are in an immovable state.

In such a neutral state, the pin 36 protruding from the rear end surface of the drive gear 33 with an eccentric amount ε is aligned with the angle α position below the horizontal line H and clockwise from the vertical line Nl in FIG. driven gear 3
A pin 3 protrudes from the rear end surface of 4 with an eccentric amount ε.
7 above the horizontal line H and aligned clockwise from the vertical line Nr at the same angle α position to initialize the gear mechanism.

The inner end of the tie rod 13 for the left rear wheel is pivotally supported on the eccentric pin 36 of the drive gear 33 which has been initially set in this way, while the eccentric pin 3 of the driven gear 34 is
At 7, the inner end of a tie rod 13 for the right rear wheel is pivotally supported.

Note that knuckle arms 14, 14 are connected to the outer ends of the tie rods 13, 13, and the knuckle arms 1
Rear wheels 16, 16 are supported by axles 15, 15 that protrude outward from wheels 4, 14.

When the steering wheel 1 is operated, the rack shaft 21 of the front wheel steering gear box 20 moves left and right.
The driven pinion shaft 22, which engages with the left half of the rack and rotates left and right, outputs the rotation necessary for steering the rear wheels, and inputs the rotation to the input shaft 31 of the rear wheel steering system via the linkage shaft 24, Input shaft 31
rotates to the left or right.

As the input shaft 31 rotates, a drive gear 33 integrated at the rear end and a driven gear 34 meshing with the drive gear 33 rotate in the opposite direction. The rotation of both gears 33, 34 causes eccentric pins 36, 37 provided on the respective gears 33, 34 to perform crank rotation in opposite directions.

Moreover, since both eccentric pins 36 and 37 are initially set symmetrically and offset by a predetermined angle α as described above, the left and right tie rods 13 and 1
3. Rear wheel 16 via the nutkl arms 14, 14,
16 are steered with different steering angle functions as shown in FIG.

That is, depending on whether the steering angle is turned to the right or to the left, the left rear wheel 16 turns the steering wheel 1 to the right, as shown in FIG. 4a, and the right rear wheel 16 turns to the right, as shown in FIG. 4b. When steering the vehicle, the left rear wheel 16 is on the outside of the turn, and the steering angle of the left rear wheel 16 to the left, which is in the opposite phase to the front wheels 6, mainly contributes to the turning characteristics of the vehicle. Since the rear wheels 16 are on the inside of the turn, their influence on turning is considerably reduced. In the case of left-handed cutting, the left and right sides have opposite effects.

In other words, the maximum steering amount of the rear wheel on the outside of the turn in an opposite phase to the front wheel steering is larger than the maximum steering amount in the same phase, and therefore it has a large effect on the turning performance of the vehicle. Even with the ideal steering angle function of the rear wheel on the outside of the turn, the vehicle will be able to make a turn close to the ideal.

In the embodiment, the rotary body mechanism was composed of two gear mechanisms, but it may also be composed of three gear mechanisms, two sprocket mechanisms connected by a chain, a belt,
The pulley mechanism may be composed of two pulley mechanisms connected by an endless running belt such as a wire.

As is clear from the above description, according to the present invention, the left and right rear wheel steering tie rods are positioned at the neutral position of the steered wheels with respect to the end surfaces of the respective rotary bodies with parallel axes connected to the input shaft with the axes oriented in the longitudinal direction. In,
As the wheels were pivoted vertically away from the horizontal line that connects the individual axes, and at a predetermined angle offset to the left and right from the vertical line that passes through the individual axes, the steering of the rear wheels on the inside of the turn was sacrificed. As a result, the shape of the steering angle function of the rear wheel on the outside of the turn, which greatly contributes to the turning characteristics, can be made into an ideal shape, and the turning of the vehicle can be made close to ideal.

[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 to which the present invention is applied, and FIG. 2 is a front view of a rotating body mechanism. , Figure 3 is a sectional view taken along line 3-3 in Figure 2,
Figure 4a is a diagram of the steering angle of the steering wheel versus the steering angle of the left rear wheel.
FIG. 4b is a diagram showing the steering angle of the right rear wheel. 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 an input shaft,
33 and 34 are rotating bodies.

Claims (1)

[Scope of Claims] 1. A rotating body is integrated with an input shaft whose axis that rotates in conjunction with the steering wheel is oriented in the front-rear direction, and at least two axes that rotate in conjunction with the steering wheel including the rotating body are integrated. A parallel rotating body mechanism is constructed, and the tie rods for steering left and right rear wheels are pivotally supported on separate rotating bodies eccentrically from the axis, and the rear wheels can be steered along with the front wheels by steering operation of the steered wheels. In the steering system for a vehicle, when the steering wheels are in a neutral position, the left and right rear wheel steering tie rods are moved away from the horizontal line connecting the respective axes in the vertical direction with respect to the end face of each rotating body, and 1. A steering device for a vehicle, characterized in that the steering device is pivoted outwardly in the left-right direction by a predetermined angle from a vertical line passing through each axis.