JPH0374290A - Variable system of wheel base - Google Patents

Abstract

PURPOSE:To improve straight running stability at the time of high speed running and braking, and small turning property at the time of low speed turning by providing such a constitution as detecting the running state of a vehicle to change a wheel base. CONSTITUTION:When a set value or more of vehicle speed is detected by a vehicle speed sensor 1, and left and right wheel side moving means 6, 8 are energized through a control means 4 to move a rear wheel support member backward, or to conduct braking, ON signal of a brake switch 2 which is a detecting means locks the moving means 6, 8 through the control means 4. When low speed turning operation is conducted, the vehicle speed lower than the set value is detected by the vehicle speed sensor 1, the left and right wheel side moving means 6, 8 are energized backward through the control means 4 to move a trailing arm frontward. A set value or more of steering angle of steering is detected by a steering angle sensor 3, and the actuators of the left and right moving means 6, 8 are mutually reversely operated through the control means 4.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a variable wheel base system that changes the wheel base depending on the driving condition of a vehicle.

(Prior Art) Generally, the main specifications of a passenger car are constant and do not change freely. In other words, the wheel base and tread are fixed to the dimensions specified for the vehicle. In conventional passenger cars, for example, the tip of a 1-railing arm fixed to the rear axle is fixed to the vehicle body, so the wheel base remains constant during driving.

(Problem to be solved by the invention) The driving conditions of a passenger car vary widely depending on the road conditions and driving purpose, such as high speed driving, low speed driving, turning driving, or braking. The longer the wheel base, the better; the shorter the wheel base, the better the turning ability when turning, such as when parking in a garage. However, since the wheel base is constant, there are problems such as poor straight-line stability when driving at high speeds, and difficulty in turning around when driving on narrow roads or parking in a garage.

(Means for Solving the Problems) The present invention has been made for the purpose of solving the above-mentioned problems of the prior art and improving straight-line stability during high-speed running and braking, and turning performance at low speed. A moving means for moving the supporting member in the traveling direction relative to the vehicle, a detecting means for detecting the running state of the vehicle, and a control for inputting a signal from the detecting means and outputting a signal to energize or lock the moving means. It is characterized by comprising means.

(Function) The detection means detects that the running state of the vehicle, for example, the vehicle speed has exceeded a set value, and the control means energizes the moving means to move the rear wheel support member rearward or brake the vehicle. When the operation is performed, the on signal of the brake switch, which is the detection means, locks the moving means via the control means, and furthermore, when performing a low-speed turning operation, the detection means detects that the vehicle speed has become lower than the set value and controls the vehicle. The moving means is biased in the opposite direction through the means to move the trailing arm forward, and then when it is detected that the steering angle of the steering wheel has exceeded the set value, the moving means is actuated to the left and right through the control means. Actuate the barrel actuators in opposite directions.

(Example) Hereinafter, the illustrated example will be described in detail. FIG. 1 is a conceptual diagram of the present invention. This system consists of vehicle speed sensor 1. Brake switch 2 and steering angle sensor 3
, a controller 4 as a control means, a left wheel actuator 6 with a left side position sensor 5 and a right side position sensor 7
It has a right wheel actuator 8. In FIG. 2, reference numeral 9 indicates a rear axle which is a rear wheel support member, and the rear axle 9 has a trailing arm 1.
0 is concatenated. The tip of the trailing arm 10 is pivotally attached to an arm bracket 11, and the arm bracket 11 is attached to the slider 12 substantially integrally. A ball screw is attached to the slider 12 and is screwed onto the gear shaft 13.
is rotatably mounted on both ends with brackets 14°14. Bracket 14゜14 is gear shaft 1
3 are fixed to the vehicle body, respectively, so as to be arranged along the vehicle traveling direction. An output shaft of a motor 15 is connected to one end of the gear shaft 13. Reference numeral 16 denotes a guide rail arranged parallel to the gear shaft 13, and the slider 12 is fitted into the guide rail 16 and is movable by the rotation of the gear shaft 13.

In this case, the moving means on the left rear wheel side or the right rear wheel side is the motor 15. Gear shaft 13. Each includes a guide rail 16° slider 12, an arm bracket 11, and the like. The vehicle speed sensor 1, which is one of the detection means, may be a known vehicle speed sensor, for example, 60 km/h.
For h or more, it is sufficient to output an on signal. The controller 4, which is a control means, has a circuit leading from the vehicle power supply to the motor, and a circuit that receives signals from the detection means and outputs signals for normal rotation, stop, and reverse rotation of the motor. Energizing the moving means means that the motor rotates forward or backward; locking the moving means means that the motor rotates forward or backward; locking the moving means means that the motor rotates forward or reverse;
This means that the stop is sustained.

Note that position sensors (not shown) are attached to the front and rear ends of the stroke of the slider 12, and these position sensors detect the passage of the slider 12 and send a signal to the controller 4 to stop the rotation of the motor 14. It has become. Note that the position of the slider 12 to be detected by the position sensor is variable to a desired value via the controller 4. Furthermore, the amount of movement of the rear wheels is limited to a range within the tire house that does not cause interference, but at high speeds the amount by which the tires swing upward is small, so it can be considered that this interference will not occur.

The means for detecting the running state of the vehicle in the present invention is not limited to the vehicle speed sensor, but the safety of the device can be improved by adding a brake switch. That is, the motor is stopped and locked together with the braking operation to fix the rear wheel position at a set position to maintain straight-line safety.

The present invention further improves the turning ability during low-speed turns by adding a steering angle sensor to the above-mentioned detection means. That is, the steering angle sensor notifies the controller 4 of the steering angle, the built-in CPU determines the rotation angle of the rear axle corresponding to the steering angle,
For example, when turning left, the right wheel motor (15) rotates forward to move the right wheel rearward, while the left wheel motor (15)
) is reversed to move the left wheel side forward. Of course, at high speeds, the motor may be rotated contrary to the above description to improve safety when changing lanes, etc.

3 and 4 show another embodiment of the invention, in which the gear shaft of the motor drive and the ball of the slider
Hydraulic cylinders 20 (20a, 20b) are used instead of the moving means in combination with a screw. The fluid pressure cylinder 20 is fixed to a body frame 21 by a bracket 22, and has an actuator 2 that expands and contracts.
bracket fixed to the tip of 3], 1a is slider 1
2a and is mounted substantially integrally with the body frame 21.
a trailing arm 10 that moves along a slide rail 24 fixed to and pivoted to a bracket lla;
It is designed to move forward and backward. If it is necessary to rotate the rear axle, it is essential that the body frame is substantially integral with the rear axle.

(Effects of the Invention) As is clear from the above explanation, the present invention detects the running condition of the vehicle and changes the wheel base, which improves straight-line stability when driving at high speeds and when braking, and improves the stability when turning at low speeds. This has the effect of improving maneuverability.

[Brief explanation of drawings]

FIG. 1 is a conceptual diagram of the present invention, FIG. 2 is a partial external perspective view showing one embodiment of the present invention, and FIGS. 3 and 4 are a partial plan view and rotational view showing another embodiment of the present invention. FIG. 3 is a plan view showing the rotation of the rear axle at times. 1.2.3...Vehicle speed sensor as detection means, brake/
Switch, steering angle sensor, 4...control means, 5, 7...position sensor, 6.8...movement sensor, 9...rear axle serving as a rear wheel support member. =7-8-

Claims (1)

[Claims] A moving means for moving the rear wheel support member in the traveling direction relative to the vehicle, a detecting means for detecting the running state of the vehicle, and a signal from the detecting means is inputted to generate a signal for energizing or locking the moving means. and control means for outputting a variable wheel base.