JPH0443811B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a vehicle height adjustment device for an automobile or the like that can be adjusted to two vehicle height levels, high and low. The present invention relates to a vehicle height adjustment device that can be automatically switched depending on vehicle speed.

2. Description of the Related Art In vehicles such as passenger cars, a vehicle height adjustment device that can adjust the vehicle height to two levels, high and low, has been proposed and put into practical use. Such a vehicle height adjustment device normally maintains the vehicle height at a low position, and based on this low vehicle height level, adjusts the vehicle height appropriately according to changes in vehicle load, and also adjusts the vehicle height on uneven terrain, snowy roads, etc. By changing the vehicle height to a higher position while driving, it is possible to prevent the vehicle body from touching the ground and improve drivability. In this way, the vehicle height at a low position always keeps the vehicle height at an appropriate height, while the vehicle height at a high position mainly serves as an emergency vehicle to avoid bad road conditions.

In actual driving, it is extremely rare for a vehicle to travel at high speed on a road surface where the vehicle body touches the ground, and there is almost no need to travel at a high vehicle height on a flat road surface. Therefore, in consideration of this situation, first, while driving at a high vehicle height position, when the vehicle speed exceeds a specified value, the vehicle height position changes to a low vehicle height position, and after a certain period of time, when the vehicle speed falls below a separately determined vehicle height position, the vehicle height position changes again. A control method for recovery was proposed (Japanese Patent Application No. 57-65002). According to this control method, after the vehicle height is switched to the high position, the vehicle height can be automatically adjusted according to the vehicle speed, so that drivability can be improved.

However, when a high vehicle height position automatically changes to a low vehicle height position as the vehicle speed increases, it generally means that the road surface has changed to a better condition. Therefore, it is not necessarily necessary to raise the vehicle height just because the speed has become low.

The present inventor has developed the present invention in view of the above circumstances, and an object of the present invention is, for example, to provide a vehicle height adjustment device having a two-stage switchable vehicle height position level of high and low. In the initial state, it is set to the low position, and it is always manually switched from the low position to the high position, and after being manually switched to the high position, it is automatically switched to the low position based on the vehicle speed. An object of the present invention is to provide a vehicle height adjustment device that matches the actual driving conditions.

A preferred embodiment of the present invention will be described in detail below with reference to the accompanying drawings.

First, a vehicle height adjustment device that can switch the level of the vehicle height position into two levels, high and low, which is the premise of the present invention, will be outlined.

FIG. 1 is a block diagram showing the configuration of a vehicle height adjustment device according to the present invention.
is a signal processing device that performs predetermined logical operations based on input signals and outputs a constant control signal. The signal processing device 1 is selectively inputted with a sensor output signal from either a high-level vehicle height sensor 3 or a low-level vehicle height sensor 4 via a switching circuit 2. The signal is applied to the actuator 6 via the output circuit 5.

The sensors 3 and 4 are disposed at appropriate locations on the vehicle body, and each outputs a signal for adjusting the vehicle height based on independently set levels. That is,
At each vehicle height position, when the vehicle height is not at a predetermined level, a signal is output to activate the vehicle height adjustment device to bring the vehicle height to the corresponding level, and when the vehicle height is at the predetermined level, the vehicle height adjustment device is output. A signal is output that causes the to become inactive. The switching circuit 2 mainly consists of a switching switch 2a made of, for example, a semiconductor, and a switching instruction circuit 8 based on a push-button reset type manual switch 7 that is normally installed near the driver's seat and operated by the driver or the like. Depending on the output, one of the output signals of the sensors 3 and 4 is transmitted to the signal processing circuit 1. The output circuit 5 generates an output signal for operating an actuator 6 based on a control signal output from the signal processing circuit 1, and the actuator 6 is used for, for example, an operation for changing the vehicle height attached to a suspension system of a vehicle. It is, for example, a valve member provided in a pressure oil supply path that enables the supply of hydraulic pressure from a hydraulic pump.

According to the above, if the vehicle height is at the selected high or low vehicle height position level, the vehicle height adjustment device is in an inactive state, and when it is outside the vehicle height position level, it is in an active state. The vehicle height is adjusted as appropriate, and the vehicle height is adjusted to an appropriate position at the relevant level. The relationship between the output signals of sensors 3 and 4 is such that one sensor detects when the vehicle height is at a predetermined level, and the other sensor detects when the vehicle height is outside the predetermined level. Therefore, in a state where the vehicle height is adjusted to the appropriate position based on the output signal of either sensor 3 or 4,
For example, by changing the connection relationship in the switching circuit 2 based on the manual switch 7 and the switching instruction circuit 8, the vehicle height is adjusted so that the vehicle height is at an appropriate position with respect to the vehicle height position levels of other sensors. Therefore, in this case, the vehicle height is adjusted so that when the connection is switched from sensor 4 to 3, the vehicle height becomes higher, and when the connection is switched from sensor 3 to 4, the vehicle height is lowered.

A vehicle speed setting circuit 10 for switching the vehicle speed sensor 9 is connected in series to the switching instruction circuit 8 . The vehicle speed sensor 9 generates a pulse train signal in response to, for example, the rotation of the wheels of the vehicle, and the switching vehicle speed setting circuit 10 measures the pulses sent from the vehicle speed sensor 9 and converts them into voltage using, for example, a frequency/voltage conversion circuit. This is a circuit that converts the voltage and outputs a high level output when the value is greater than the set voltage.
If such a high level output is output, the switching instruction circuit 1
0, the changeover switch 2a is connected to the sensor 4. As a result, when the vehicle speed becomes higher than the set vehicle speed, the vehicle height is automatically switched to a low level when the vehicle height is at a high level.

Next, the structure of the manual switch 7 and the switching instruction circuit 10 will be explained based on FIG.

The switching instruction circuit 10 is one flip-flop 11.
and an OR circuit 12, the output single of the OR circuit 12 being connected to the reset terminal R of the flip-flop 11. Further, a resistor 13 and a manual switch 7 are connected in series between the power supply terminal +Vcc and the ground, and the upper terminal of the manual switch 7 is connected to the input terminal I of the flip-flop 11. The output Q of the flip-flop 11 is configured to be applied to the changeover switch 2a, and when the state of the output Q changes from low level to high level, changeover switch 2a switches the connection from sensor 4 to sensor 3, and from high level to low level. It is assumed that when the level changes, the connection is switched from sensor 3 to sensor 4.

Two inputs are prepared for the OR circuit 12, one of which is connected to the output terminal of the switching vehicle speed setting circuit 10, and the other is set to the normal vehicle height position (low position) as an initial condition after the engine is started. The configuration is such that, for example, a starter signal _s1 or the like is added to set the start signal.

In the above, when the engine is started, the starter signal _s1 etc. is input to the reset terminal R of the flip-flop 11 via the OR circuit 12, and its output Q is held at a low level, and the connection state of the changeover switch 2a is determined by the sensor 4. Hold the connection with the terminal. Therefore, during normal driving, the signal processing circuit 1 inputs the output signal from the sensor 4, and adjusts the vehicle height based on the signal as described above.

Next, when the road surface becomes bad, the manual switch 7 is operated. Then flip-flop 11
A signal enters the input I of the sensor, and the level of the output Q changes from low to high based on the rising edge of the signal, so that the connection relationship of the changeover switch 2a changes from sensor 4 to sensor 3. Therefore, the vehicle height is adjusted based on the output signal of the sensor 3, and as a result, the vehicle height becomes a high vehicle height position.

In the above driving condition, when the vehicle speed becomes equal to or higher than the set vehicle speed, an output is output from the switching vehicle speed setting circuit 10, and is passed through the OR circuit 12 to the flip-flop 11.
A reset signal is input to the reset terminal R of. Therefore, the level of the output Q changes from high to low, the connection of the changeover switch 2a is switched from the sensor 3 to the sensor 4, and the vehicle height becomes a low vehicle height position.

After that, even if the vehicle speed becomes lower than the set vehicle speed, the output Q of the flip-flop 11 does not change and the connection of the changeover switch 2a is maintained by the sensor 4, so the vehicle height remains at the low position and automatically moves to the high position. It will never become.

Therefore, in order to change the vehicle height to the desired position, it is necessary to operate the manual switch 7 again, and in this invention, in order to change the vehicle height from a low level to a high level, the manual switch 7 must be operated. .

Further, by operating the manual switch 7 once to raise the vehicle height, and then operating the manual switch 7 again, the vehicle height can be lowered based on the above operation.

In addition, the push-button manual switch 7 as described above
Two are prepared to generate a signal for switching to a high vehicle height position and a signal for switching to a low vehicle height position, and the signal for switching to a high vehicle height position is connected to the set terminal of the flip-flop 11. The same effect as described above can also be achieved by applying a signal for switching to a lower vehicle height position to the reset terminal.
However, in this case, everything is done manually, but even if you inadvertently operate it twice, the vehicle height will not be reversed, and the vehicle height will always be maintained. It is easy to check.

Although the content of the present invention has been clarified by the above-mentioned embodiments, the present invention is not limited to the above-mentioned embodiments, and it goes without saying that the design can be changed as desired without departing from the gist thereof. For example, the vehicle height level may be two or more levels.

As is clear from the above description, according to the present invention,
A vehicle height adjustment device that allows the vehicle height to be switched between high and low levels.The vehicle height adjustment device sets the vehicle height to a low level as an initial state after the engine starts, and also changes the vehicle height from a high level to a low level when the vehicle speed increases after the vehicle height is set to a high level. The vehicle height is automatically changed depending on the vehicle speed, and when the vehicle height becomes low, the vehicle height is maintained low unless the vehicle height is raised using a manual switch. It is possible to prevent the vehicle height from becoming unnecessarily high, improve ride comfort, and improve air resistance.

[Brief explanation of the drawing]

The drawings show one embodiment of the present invention, and FIG. 1 is a block diagram showing the configuration of a vehicle height adjustment device, and FIG. 2 is a circuit diagram showing the specific configuration of a manual switch and a switching instruction circuit. In the drawing, 1 is a signal processing device, 2 is a switching circuit, 3 and 4 are vehicle height sensors, 7 is a manual switch, and 8 is a switching circuit.
9 is a switching instruction circuit, 9 is a vehicle speed sensor, 10 is a switching vehicle speed setting circuit, and 11 is a flip-flop.

Claims (1)

[Claims] 1. In a vehicle height adjustment device having at least two vehicle height adjustment levels with different heights and selectively selecting a vehicle height position using a switching means,
To select a high level vehicle height position using a manual switch, switch to the high level using a switching means, and then automatically switch only the vehicle height position from the high level to the low level according to the vehicle speed. Also, a vehicle height adjustment device characterized in that the initial state after starting the engine is set to a low level.