JPS5926367A - Steering apparatus for car - Google Patents

Abstract

PURPOSE:To permit safe and easy steering operation by installing an angle indicating means which transmits sterring information to a steering wheel, in an apparatus for steering front and rear wheels, maintaining a fixed functional relation between the steering angles for front and rear wheels, by the operation of the steering wheel. CONSTITUTION:When front wheels 5 are steered by the operation of a steering wheel 1, a rear-wheel steering servoactuator 17 is driven by the control signal from a computer 20 which receives each output of a front-wheel steering angle detecting means 21 installed on a steering shaft 2 and a lateral acceleration sensor 22, and rear wheels 15 are steered through a gear box 14, and a tie-rod 14 etc. In this case, the computer 20 operates to steer rear wheels 15 in the functional relation shown by a sine curve shown in the figure, with the steering angle theta of front wheels 5. Each position of the front-wheel steering angle theta1 with which a rear-wheel steering angle alpha becomes the max. and the front-wheel steering angle theta2 with which the rear-wheels 15 are not steered and only the front wheels 5 are steered is shown on the periphery of the steering wheel 1, or a spoke is arranged at said position.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a steering system for a vehicle that steers the rear wheels together with the front wheels, and in particular, displays are attached to the steered wheels to provide the driver with front and rear wheel steering information. It relates to a steering device.

Steering of a vehicle, especially a four-wheeled vehicle, is usually accomplished by steering only the front wheels.In this case, when the front wheels begin to turn, a slip angle is created in the front wheels, and the cornering force generated by this causes the lateral movement of the vehicle body and the vehicle body. Causes yawing around the center of gravity.

On the other hand, the rear wheels generate a slip angle only when they begin to be displaced in one direction due to the yaw motion of the vehicle body.

As a result of the above, the cornering force generated by the rear wheels lags behind that generated by the front wheels by an order of 11 degrees, and due to this phase lag, the resultant force of the cornering forces of the front and rear wheels is less than the driver's intention (ll'l There is a slight time delay before the vehicle reaches the target position, and this is one of the reasons why it is difficult to steer a four-wheeled vehicle.

Therefore, the present applicant has proposed a steering system that can first steer the rear wheels in conjunction with the steering of the front wheels, and at the same time appropriately control the steering ratio between the front wheels and the rear wheels. i-j/lj offering ζ.

According to such a steering device, it is possible to effectively solve the problems in the conventional 1-V-M'C device and facilitate steering operation for four wheels, and also to reduce the minimum turning radius for four wheels. It is possible to significantly reduce the amount of traffic and make it easier to drive and park on narrow roads.

However, in this type of device, C & 1. The driver could not obtain steering information for the front and rear wheels, and in particular could not confirm the steering status of the rear wheels.

The present invention has been made in view of the above, and its purpose is to inform the driver of the ml and the turning status of the rear wheels by listening to the angle display that provides steering information to the steered wheels. To provide a steering device for a vehicle that enables driving operations while checking the vehicle, thereby further facilitating steering operations, driving on narrow roads, and parking. A preferred embodiment of the present invention will now be described in detail with reference to the accompanying drawings.

FIG. 1 is a schematic plan view showing the basic structure of a vehicle equipped with a steering device according to the present invention, FIG. 2 is a diagram showing a steering angle function,
FIGS. 3 to 5 are schematic plan views showing turning conditions of the vehicle, and FIGS. 6 and 7 are plan views of the steering wheels.

To explain the basic structure of the steering device in FIG. 1, the steering shaft 2 of the steering wheel 1 operated by the driver is a gear box
The steering rotation of the steering wheel 1 is converted into a movement of the tie rod 4 in the width direction of the vehicle body by the direction changing means, which uses a rank-and-binion system, for example.

The outer end of the tie rod 4 supports the front wheel 5.5f, and is configured to be rotatable in the left and right directions.
6, and the front wheels 5, 5 are steered in the steering direction of the steered wheel 1 by the above-mentioned movement of the tight 1st wheel 4. By attaching a control device, the steering wheel 1
The steering operation of is assisted by the power steering device.

On the other hand, 13 is a rear wheel side gear hock, and a direction change means such as a rank and pinion system installed in the gear hock 16 is connected to a rear wheel steering servo actuator 17 extending rearward. .

Furthermore, a knuckle arm 16.
are rotatably connected, and both knuckle arms 16.
A rear wheel 15.15 is rotatably supported on 16.

Further, a computer 20 is installed in the vehicle body 15, which receives signals from a front wheel steering angle detection device 21 provided on the steering shaft 2 and a lateral acceleration sensor 22 installed in the vehicle body, and controls the drive of the servo actuator 17. Moe 1shi, 1) 1f
The rear wheels 15.15 are steered with respect to the steered angle θ of the wheels 5, 5 while maintaining the functional relationship shown by the sine curve in FIG.

In Fig. 2, the horizontal axis represents the front wheel steering angle θ, and the vertical axis represents the rear wheel steering angle C! , respectively, and the rear wheel steering angle α is positive when it is in the same direction as the front wheel steering angle θ, that is, when the rear wheels 15.15 are steered in the same direction as the front wheels 5, 5, and vice versa. 15 is the front wheel 5.
5 is negative when the steering wheel is steered in the opposite direction.

In the range of O〈θ〈θ2 in Fig. 2, the rear wheels 15.15 are steered in the same direction as the μm1<front wheels 5, 5 shown in Fig. 3, especially in the range of O〈θ〈el. 1) The rear wheel turning angle α increases as the IJ wheel turning angle θ increases, but on the contrary decreases in the range θ1<θ<θ2. In this case, as shown in Fig. 3, the turning center 01 of the vehicle is located behind the extension line of the rear axle, so the turning radius R+ is large. Therefore, if the vehicle moves forward in this state, the change in direction of the vehicle will cause it to move to the right in the figure. The moving part becomes larger, making it easier to narrow the width in narrow spaces.

In a state where θ=·θ2, as shown in FIG. 4, the rear wheels 11<15.15 are not steered, and only the front wheels 5, 5 are steered. In this case, as shown in Fig. 4, the turning center 02 of the heavy vehicle is on the extension line p2 of the rear axle, and the ratio of the change in direction of the vehicle when moving forward and the movement 11F to the right is the same as that of the general front Turn the two-wheel steering vehicle and it will turn.

In FIG. 21, within the range of θ2 < θ3, the rear wheels 15.15 are steered in the opposite direction to Otl'<front wheels 5.5 shown in FIG. At this time, the turning center of the vehicle is 03
is located in front of All<extension line of the rear axle -el shown in FIG. 5, and the turning radius IL3 becomes small. Therefore, in this case, it is possible to easily make a U-turn on a narrow road or pass through a bend.3 As shown above, depending on the value of the front wheel steering angle 0, the rear wheels are steered at 15°15 as shown in Figure 3. Since the situation is as shown in FIGS. 5 to 5, the values 01 and θ2 of the front wheel turning angle θ should be displayed on the circumference 1- of the steered wheel 1 as indicated by diagonal lines in FIG. By using the arrangement of the spokes la and Ia shown in Fig. 7, the driver can imagine the steering patterns shown in Figs. This makes it easier to drive on narrow roads and park in Tokyo.

As is clear from the above explanation, according to the present invention, the driver can operate the steering wheel while checking the steering status of the front and rear wheels by checking the angle display on the steering wheel. Therefore, it is possible to greatly simplify steering operations, driving on narrow roads, and parking.

[Brief explanation of the drawing]

The drawings show one embodiment of the present invention. Fig. 1 is a schematic diagram of a heavy vehicle, Fig. 2 is a diagram showing the steering angle function, and Figs. 3 to 5 are diagrams showing the turning of the vehicle. Schematic plan views showing the situation, Figures 6 and 7, are the south plane of the steering wheel. In the drawings, 1 is the steering wheel, 2 is the steering shaft, 3.13 is the gear box, 4.14 is the tie rod, 5 is the front wheel, 15 is the rear wheel,
17 is a blade-ho actuator, 20 is a computer, 2
1 is a front wheel steering angle detection device, and 22 is a lateral acceleration sensor. IJ Figure 6 Figure 7

Claims (1)

[Claims] In a steering system for a vehicle, in which front and rear wheels are steered by steering operation of a steered wheel while maintaining a fixed functional relationship between these steering angles, an angle display for inputting steering information to the steered wheels. A steering device for a vehicle, characterized in that it is attached with.