JPS61205559A - Steering stabilizing device for vehicle - Google Patents

Abstract

PURPOSE:To prevent too light steering operation under high speed travelling while to suppress rotary vibration of steering wheel by applying proper torque onto the steering shaft of vehicle. CONSTITUTION:The steering apparatus is provided with a mechanism for reducing the rotation of steering shaft 1 through a drive gear 2 and driven gears 3, 4 and transmitting to a cam ring 5. A cam face 6 is formed on the outercircumferential face of cam ring 5 and a ball 8 is pressed through a pressing chip 7 against said cam face 6. Hydraulic pressure will function through a hydraulic pump 12 for delivering oil flow proportional to the cam speed onto the rear face of said pressing chip 7 thus to produce steering feeling corresponding with the car speed.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention adds appropriate torque to the steering shaft of a vehicle, prevents the steering wheel from being too light when driving at high speeds, makes it easy to return to and maintain a neutral position, and makes it possible to control the rotation of the steering wheel. This invention relates to an automobile steering stabilization device that suppresses photographing.

The object of the present invention is that when a car is running at high speed, the steering force is generally too light, the angle of play of the steering wheel, and the angle of insensibility of the steering force are large, making it difficult to return to and maintain the neutral position, and reverse transmission from the front wheels. The present invention aims to eliminate the above-mentioned problems, such as rotational vibration of the steering wheel due to external disturbances, which causes anxiety and fatigue to the driver.

Embodiments of the present invention will be described below with reference to the drawings.

(1) As shown in Fig. 4, the rotation of the steering shaft 1 is decelerated by the driving gear 2 and the driven gear 3-4, and a plurality of symmetrical cam surfaces 6 are formed on the outer peripheral surface over a required angle ψ. The torque is transmitted to the cam ring 5 which has a gear meshing with the driven gear 4 on its inner circumferential surface, and the cam surface 6 is pressed by the pusher 7-8, so that when the steering shaft 1 is in the neutral position, an initial torque is generated as shown in FIG. T
A steering stabilizing device for an automobile configured to add torque shown by hatching in FIG. 8, which gradually decreases as the steering wheel 9 rotates with the steering shaft 1.

(2) As the vehicle speed increases, hydraulic pressure P, which increases as shown in FIG. 3, is applied to the pusher 7-8, and the cam surface 6
2. The steering stabilization device for a motor vehicle according to claim 1, wherein the steering stabilization device is configured to press.

The pressing force of the presser 7-8 in the first term is a constant hydraulic pressure,
Alternatively, a spring 16 shown in FIG. 7 may be used.

The cam surface 6 maintains a contact angle ω with the pusher 8 at the middle position of the steering shaft 1 as shown in FIGS. 4 and 9, and the cam ring 5
As the contact angle ω gradually decreases as the surface rotates, a curved surface that becomes 0 degrees at the required angle ψ is formed.

The installation position of this device may be any position as long as it can take out the rotation from the steering shaft 1 through the gear mechanism.
The embodiment shown in FIG. 1 shows a state in which the steering shaft column 10 is mounted on the side (2).

The operation of the present invention will be explained below.

FIG. 9 shows the state of the steering shaft 1 in its neutral position. When turning the steering shaft 1 from this neutral position, if the initial pressing force is F and the contact angle between the cam surface 6 and the pusher 8 is ω, then the fourth As shown in the figure, the torque ti generated on the upper and lower cam surfaces 6 is expressed by the following equation.

ti=2×F×oc×Tanω The above ti is the gear 5-4-3- of the gear mechanism shown in FIG.
2, the signal is transmitted to the steering shaft 1, giving the steering handle 9 an appropriate turning feeling.

For example, if the reduction ratio of the gear mechanism is /R, then the torque Ti of the steering wheel is expressed by the following equation.

Ti=2×F×oc×Tanω×■/R For example, if the cross-sectional area A of the presser 7 is 2 cm2 and the pressure P is 10 kg/cm2, F=10×2 kg, oc is 3.5 cm,
When ω is 45 degrees and the reduction ratio is 1/6, Ti is as follows.

Ti=2×20×3.5×1×1/6≒23kgcm.

Next, the subsequent cutting state of the steering shaft 1 will be explained. Following the cutting of the steering shaft 1, the contact angle ω decreases and the torque ti gradually decreases. Next, the contact point between the cam ring 5 and the pusher 8 When the leak point shown in Figure 4 is reached, ω becomes 0 degrees and the torque ti also disappears, during which time the torque T transmitted to the steering shaft 1
i operates along the upper arrow shown by hatching in FIG.

Next, the turning state of the steering shaft 1 will be explained. As the steering shaft 1 turns back, the friction loss is subtracted from the torque Ti, and along Tr shown in FIG. Return while maintaining rudder torque.

Next, the effect of suppressing rotational vibrations that are reversely transmitted to the steering shaft 1 during high-speed running will be described.

The rotational vibration that is reversely transmitted from the front wheels to the steering shaft 1 is suppressed by the initial torque ti generated by the pusher 7-8 and the cam surface 6.

Next, the relationship between the rotation angle of the steering shaft 1 and the cam ring 5 will be described. If the torque passive angle of the steering shaft 1 is Φ, the torque generation angle of the cam surface 6 is ψ, and the reduction ratio of the gear mechanism is I/R, then the passive angle Φ is as follows.

Φ=ψ×R For example, if ψ is 20 degrees and R is 6, Φ will be 120 degrees. The passive angle Φ can sufficiently cover the steering angle at high speeds.

Next, a case in which hydraulic pressure is applied to the pusher 7, which increases as the vehicle speed increases as described in item 2 above, will be explained. The hydraulic circuit is shown in FIG. 5.The hydraulic pump 12 is given a rotation proportional to the vehicle speed as shown in FIG.
increases in proportion to the vehicle speed V. However, when the vehicle speed exceeds a predetermined value, for example 100 km/h, the effective flow rate for boosting the pressure is kept at a constant value.

The flow rate can be increased in proportion to the vehicle speed by driving the hydraulic pump 12 with engine rotation, transmission rotation, or an electric motor whose rotation speed is controlled according to the vehicle speed.

The effective flow rate for boosting the pressure can be maintained at a constant value by using a known flow control valve 13 and metering orifice 14 shown in FIG. In order to obtain hydraulic pressure that increases as the vehicle speed increases, it is possible to flow a flow rate proportional to the vehicle speed into the hydraulic circuit shown in FIG. 5 and take out the pilot pressure P from upstream of the orifice 15 for pressure generation. , in this case, the cross-sectional area of the orifice 15 is A
, if the flow rate is Q, then the pilot pressure P is expressed by the following equation.

P=Q2/A2×n The relationship between pilot pressure P and vehicle speed V is shown in FIG. 3. For example, if Q is 1.5 l/min and A is 0.5 mm2, then P is 10.7 kg/cm2.

As explained above, the pressure P that increases as the vehicle speed increases is applied to the presser element 7, and the Ti acts strongly at high speeds, and Ti is reduced at medium and low speeds, until the speed completely decreases.
Get proper steering feel.

The effects of the present invention will be explained below.

First, I will explain the disadvantages of conventional steering characteristics.When the steering wheel is turned, it operates along the upper dotted line in Figure 8, and the steering force becomes lighter at high speeds.
The play angle α of the steering wheel is large and there is no feeling of turning.

When the steering wheel is turned back, the steering wheel operates along the dotted line on the lower side of Figure 8, and the insensible angle β of the holding force is large, and the early disappearance of the holding force makes it impossible for the steering wheel to return to the neutral position and hold it. It becomes stable.

The steering wheel is caused to rotate and vibrate due to external disturbances that are reversely transmitted from the front wheels. The above-mentioned problems cause anxiety and fatigue to drivers.

The present invention solves the above-mentioned problems.

The effects are listed below.

a. Prevents the steering force from being too light when driving at high speeds and provides an appropriate steering feel.

b. When turning the steering wheel, apply appropriate steering torque and actively return to and hold the neutral position.

c. Rotational vibration of the steering wheel due to disturbances from the front wheels is suppressed by the initial torque of the cam surface.

d. In the case of the structure according to claim 2, an appropriate steering feeling is provided over the entire speed range.

[Brief explanation of drawings]

FIG. 1 is an overall view showing the mounting position of this device, FIG. 2 is a characteristic diagram showing the relationship between vehicle speed and flow rate as claimed in claim 2, and FIG. 3 is a characteristic diagram showing the relationship between vehicle speed and pressure. FIG. 4 is a vertical sectional view showing the main parts of the device, and FIG. 5 is a second claim.
Hydraulic circuit diagram in Section 6, Fig. 6 is a sectional view taken along line A-A in Fig.
The figure is a sectional view of the pressing part when the pressing force is obtained by a spring, Figure 8 shows the steering characteristics, the horizontal axis is the steering angle, the vertical axis is the torque, the solid line shows the present device, and the dotted line shows the conventional one. FIG. 10 is an explanatory diagram showing the operation of the cam surface. 1 is a steering shaft, 2 is a driving gear, 3-4 is a driven gear, 5 is a cam ring, 6 is a cam surface, 7-8 is a pusher, 9 is a steering handle, 10 is a steering shaft column, 11 is a housing, 12 is a A hydraulic pump, 13 a flow control valve, 14 a metering orifice, 15 an orifice, and 16 a spring.

Claims (2)

[Claims] (1) In an automobile steering system, the rotation of the steering shaft is decelerated by a gear mechanism, and the outer peripheral surface has a plurality of symmetrical cam surfaces over a required angle, and the inner surface is a gear that meshes with the gear mechanism. The torque is transmitted to a cam ring having a cam ring, the cam surface is pressed by a presser, an initial torque is applied at the neutral position of the steering shaft, and a torque that gradually decreases as the steering wheel rotates together with the steering shaft is applied. An automobile steering stabilization device configured with (2) The steering stabilization device for an automobile according to item 1, wherein the device is configured to apply hydraulic pressure that increases as the vehicle speed of the automobile increases to the pusher to press the cam surface.