JPS6121806A - Ground clearance adjuster of automobile - Google Patents

Abstract

PURPOSE:To prevent ground clearance adjusting actions which occur frequently because load is varied while a vehicle runs on an upgrade or a downgrade slope by providing a logic circuit by which a lag time of output generation from the starting point of the ground clearance adjusting action is shortened if the vehicle is in the stationary state while the lag time thereof is prolonged during the running period of the vehicle. CONSTITUTION:The stop and run determining circuit 10 of a controller 5 generates a stop output or a running output in accordance with the signal from a car speed sensor 7. When each of the signals from ground clearance sensors A-D is input to the controller 5, the determining circuit 10 has an AND circuit 11 generate an AND output to actuate a timer 13 if the circuit 10 determines that the vehicle is kept in the stop state. When the specified period of the timer 13 passes, the timer generates an output, by which solenoid valves L1-L6 are electrified via a control circuit to adjust a ground clearance. If the determining circuit determines that the vehicle is running, an AND circuit 12 and a timer 14 are similarly activated and after the specified time of the timer 14 passes, the timer 14 electrifies the solenoid valves L1-L6 to adjust the ground clearance. Unless it passes the output delaying time, the ground clearance will not be adjusted.

Description

[Detailed description of the invention] Industrial applications The present invention relates to a vehicle height adjustment device for an automobile.

Conventional technology In vehicle wheel suspension systems that use air suspensions that utilize the volumetric elasticity of air sealed inside, the vehicle height can be raised by supplying air from the outside to the air sealed portions of the air suspension. By discharging the enclosed air to the outside, the vehicle height can be lowered.

Therefore, conventionally, vehicle height sensors are provided in the air suspensions of all the front, rear, left, and right wheels, and air supply and exhaust are performed independently for each air suspension based on the up signal or down signal of each vehicle height sensor. Accordingly, a vehicle height adjustment device that always maintains the vehicle posture in a normal state has been developed (for example, Japanese Patent Application Laid-Open No. 58-1128).
(See Publication No. 17).

Problems to be Solved by the Invention In the vehicle height adjustment device as described above, a timer is provided in each of the input circuits for the up signal and down signal of each vehicle height sensor to the control device, and the timer sets the up signal and down signal of each vehicle height sensor. Signals that last for a short time less than the set time are cut off here, and the signal is input only when the signal continues for a set time or more. This prevents the control device from operating due to changes.

When adjusting vehicle height, it is desirable to respond as quickly as possible to changes in load caused by passengers getting on and off or loading luggage while the vehicle is stopped, so the timer is normally set to about 10 seconds. If this setting is made, there is a problem that if the load on each wheel changes for longer than the above-mentioned setting time due to slight uphill slopes while driving, the vehicle height adjustment operation will be performed and driving stability will be lost. .

Means for Solving the Problems The present invention provides vehicle height sensors in the suspension sections of the front, rear, left and right wheels, and raises or lowers the vehicle height of each suspension based on the up signal or down signal of each vehicle height sensor. In a car equipped with a control device,
We have installed a logic circuit that sets the output delay time from when the up signal or down signal of each vehicle height sensor is input until the vehicle height adjustment starts to be small when stopped and large when driving. This is a characteristic feature.

By adopting the above-mentioned structure, the present invention allows the vehicle height adjustment to be started within a short period of time when passengers are getting on and off while the vehicle is stopped, and when loading luggage. Vehicle height adjustment operations that occur can be prevented.

Example The details of the present invention will be explained below with reference to the accompanying drawings.

In Figure 1, 1 is a compressor, 2 is a dryer, 3
is a reserve tank, and when the compressor 1 is driven, air is press-fitted and stored in the reserve tank 3 via the dryer 2 and the solenoid valve Ll, and the vehicle height sensors installed on the front, rear, left and right air suspensions FL, FR, RL, and RR. Based on the signals A, B, C, and D, each air suspension FL, FR, and RL receives air press-fitted and stored in the reserve tank 3.

It is possible to raise the vehicle height by supplying air to each of the air sealing sections of the RR, or to lower the vehicle height by opening the exhaust valve L2 and discharging the air sealed in the air sealing sections to the outside. It has become.

L3, L4, L5, and L6 are air supply/exhaust solenoid valves that respectively control the air supply/exhaust to each air sealing section of each air suspension FL, FR, RL, and RR.

4 is a pressure sensor which operates a drive control solenoid L7 of the compressor 1 to drive the compressor 1 when the air pressure in the reserve tank 3 falls below a predetermined value, thereby bringing the air pressure in the reserve tank 3 to a predetermined value. It is designed to be kept.

Reference numeral 5 denotes a control device, and the control device 5 controls the input of the signals when each signal (down signal or up signal) of the vehicle height sensors A, B, C, D exceeds a set time (for example, about 10 seconds). Based on the signal, control the energization to each solenoid valve (Ll to L6) that adapts to the signal,
For example, the air supply/exhaust solenoid valve and exhaust valve L2 of an air suspension equipped with a vehicle height sensor that has issued a down signal may be opened to discharge air from the air suspension to lower the vehicle height, or the vehicle height sensor that has issued an up signal may be opened. The air supply/exhaust solenoid valve of the air suspension equipped with the solenoid valve L1 is opened to supply air in the reserve tank 3 to the air suspension to raise the vehicle height, and based on the signal from the pressure sensor 4, the solenoid valve L1 is It is used to control the energization of the

Furthermore, the control device 5 receives a signal from a changeover switch 6 for changing the vehicle height from a normal vehicle height to a high vehicle height, and also receives a signal from a vehicle speed sensor 7. For example, when driving on a rough road, by switching the changeover switch 6 from normal to high, the control device 5 issues a signal to supply air to each air suspension, raising the height of the vehicle, and driving on a rough road. It is possible to prevent accidents such as the vehicle body touching the ground while driving, and for example, when driving at high speed, the control device 5 controls the air in the air sealed portion of each air suspension to the outside in response to a signal from the vehicle speed sensor 7. It is designed to issue a signal to cause the exhaust to be ejected, lower the vehicle height, and improve high-speed driving stability.

Note that 8 represents a power source, and 9 represents a power switch.

In a vehicle equipped with the vehicle height adjustment device as described above, the vehicle height sensors A and B according to the present invention.

The output delay time from when each C1D signal (down signal or up signal) is input until the vehicle height adjustment starts is set to be small (for example, about 10 seconds) when the vehicle is stopped, and large (for example, about 1 minute) while driving. A logic circuit 51 that controls
is provided in the control device 5.

In the above, whether or not the vehicle is running is determined based on, for example, the vehicle speed signal from the vehicle speed sensor 7.

An example of a control system using the logic circuit 51 is shown in the block diagram of FIG.

That is, lO is a stop/running determination circuit, 11.12 is an AND circuit, 13.14 is a timer, and the above-mentioned stop/running determination circuit 10
emits a stop output or a running output based on a signal from the vehicle speed sensor 7. When each signal (down signal or up signal) from the vehicle height sensors A, B, C, and D is input, the timer 13 is activated by the AND output of the AND circuit 11 when the vehicle is stopped. When the set time (for example, about 10 seconds) of the timer 13 has elapsed, the solenoid pulps (L1 to L6) are energized by the output of the timer 13 via the control circuit to adjust the vehicle height.

When the vehicle is running, the AND circuit 12 and the timer 14 are operated to energize the solenoid pulps (L1 to L6) after the time set by the timer 14 (for example, about one minute) has elapsed to adjust the vehicle height, as is the case when the vehicle is stopped.

Effects of the Invention According to the invention configured as described above, when the vehicle is stopped, the vehicle height can be adjusted in a relatively short period of time (for example, 10 seconds) after the signal from the vehicle height sensor is input. In addition, even if the load changes on each wheel due to going up or down a slope while driving, the vehicle height adjustment operation will continue as long as the set output delay time (for example, about 1 minute) is not exceeded. Since this is not carried out, it is possible to improve running stability, and it can bring about many practical effects such as improving the durability of the vehicle height adjustment device and eliminating the feeling of anxiety when driving on a slope.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram of an air suspension air supply/exhaust control system showing an embodiment of the present invention, and FIG. 2 is a block diagram showing a specific example of a logic circuit. 1... Compressor, 3... Reserve tank, 5...
...Control device, 51...Logic circuit, 7.
...Vehicle speed sensor, A, B, C, D...Vehicle height sensor, F
L, FR, RL, RR... Near suspension revenge, 10
. . . Stop running judgment circuit, 11.12 . . . AND circuit, 13.14 . . . Timer. that's all

Claims (1)

[Claims] In a car that is equipped with a vehicle height sensor in each of the suspension parts of a plurality of wheels and a control device that raises or lowers the vehicle height of each suspension based on the up signal or down signal of each vehicle height sensor, Vehicle height of an automobile, characterized in that it is provided with a logic circuit that sets an output delay time from when an up signal or a down signal is input until vehicle height adjustment starts to be small when stopped and large when driving. Adjustment device.