JPH0621764Y2 - Air suspension controller - Google Patents

Description

[Detailed Description of the Invention] [Industrial field of application] In this invention, the spring constant is changed in accordance with the communication and interruption of the air between the main chamber and the sub chamber, and the supply of air to the main chamber, The present invention relates to an air suspension control device that changes a vehicle height according to exhaust gas.

[Prior Art] An air suspension control device of this type adjusts a spring constant by connecting and disconnecting a main chamber and a sub chamber of the air suspension according to a running state of a vehicle and adjusting the spring constant of the air suspension. The vehicle height is adjusted by supplying and exhausting air to the main room.

Conventionally, such an air suspension control device always adjusts the spring constant over the latter, because the former adjustment of the spring constant has an effect on the transient response when the vehicle is running. I was letting it. In other words, when the adjustment timings of the two overlap, the former adjustment of the spring constant always takes precedence over the latter vehicle height adjustment.

[Problems to be Solved by the Invention] As described above, in the conventional control device, the adjustment of the spring constant of the air suspension is always prioritized over the adjustment of the vehicle height. There was a problem that it was postponed and the vehicle height adjustment time became longer.

An object of the present invention is to provide an air suspension control device that solves the above-mentioned problems of the conventional device.

[Means for Solving Problems] The present invention has the following configuration in order to achieve the above object. That is, the spring constant changes according to the communication and interruption of air between the main chamber and the sub chamber, and the supply of air to the main chamber,
Controlling an air suspension that changes the vehicle height according to exhaust gas, a running state sensor that detects the running state of the vehicle, a vehicle height sensor that detects the vehicle height, and an air suspension based on the detection signal from the vehicle height sensor. In the air suspension control device including a controller that controls the vehicle height to adjust the vehicle height and changes the spring constant based on the detection signal of the running state sensor, when the air in the main chamber is exhausted, the vehicle height adjustment takes precedence over the vehicle height adjustment. Then, the spring constant of the air suspension is adjusted according to the running state of the vehicle detected by the running state sensor, and when the air is supplied to the main chamber, the running state of the vehicle detected by the running state sensor is adjusted. In accordance with the control to adjust the spring constant of the air suspension and the air suspension based on the detection signal from the vehicle height sensor. The control for adjusting the vehicle height is performed in parallel.

[Operation] In the air suspension control device of the present invention, the spring constant adjustment control is prioritized over the vehicle height adjustment control when the main chamber is exhausted, but the spring characteristics of the air suspension become high when the main chamber is supplied with air. Because of the tendency, the adjustment control of the spring constant and the adjustment control of the vehicle height are performed in parallel without giving priority to each other. That is, priority is given to the adjustment control of the spring constant only when the main chamber is exhausted.

[Embodiment] An embodiment of the present invention will be described below with reference to the drawings.

In the figure, reference numeral 1 designates a total of four air suspensions. The left and right upper suspensions in the figure are provided on the left and right of the front of the vehicle, and the left and right lower suspensions in the figure are provided on the left and right of the rear of the vehicle. Since these four air suspensions 1 have the same structure, the right side of the front will be described below as a representative.

The main body 2 of the air suspension 1 is attached to the vehicle side and the axle side at its upper and lower ends.
A main chamber 4 is formed in the portion of the air shock absorber 3. The main chamber 4 is connected to the sub chamber 5, and an actuator 6 connects or disconnects them between them.

Such an air suspension 1 includes an actuator 6
As a result, the main chamber 4 and the sub chamber 5 are disconnected from each other, so that the spring constant is increased. Further, the vehicle height is raised by supplying air to the main chamber 4 and the sub chamber 5, and the vehicle height is lowered by exhausting air from the main chamber 4 and the sub chamber 5.

The control device of the present embodiment targets such an air suspension 1 as a control target.

A vehicle height sensor 7 is provided between the vehicle body A side and the axle B side, and detects the vehicle height based on the change in the interval between them. At least one vehicle height sensor 7 is provided on the front and rear of the vehicle.

Reference numeral 8 is a compressor for supplying pressurized air, which is connected to the main chamber 4 and the sub chamber 5 of the air shock absorber 3,
An exhaust solenoid valve 9 and a supply / exhaust solenoid valve 10 are provided in the connection path.

11 is a main tank, which is an air shock absorber 3
The main chamber 4 and the sub chamber 5 are connected to each other, and a tank solenoid valve 12 for opening and closing the main tank 11 and the supply / exhaust solenoid valve 10 are provided in the connection path. Further, the main tank 11 is connected to a controller 14, which will be described later, via a tank solenoid valve 12 and a pressure switch 13.

Reference numeral 15 denotes a running state sensor that detects a running state of the vehicle. In this embodiment, the running state sensor includes a vehicle speed sensor 16 that detects a running speed of the vehicle and a steering angle sensor that detects an operation angle of a steering wheel. 17, a brake lamp switch 18, and a throttle opening sensor 19 are used. The detection signals of the running state sensor 15 and the vehicle height sensor 7 are input to the controller 14, and the controller 14 uses the detection signals to drive the actuator 6, the compressor 8, the exhaust solenoid valve 9, and the air supply / exhaust of the air suspension 1. A tank solenoid valve 12 that controls opening / closing of the solenoid valve 10 and the main tank 11 is controlled.

Next, the operation will be described.

The controller 14 adjusts the vehicle height and the air suspension 1
Adjust the spring constant of.

First, the vehicle height adjustment will be described.

The vehicle height sensor 7 includes five or seven areas such as “low”, “slightly low”, “middle”, “slightly high”, “high”, and the like for the area to be adjusted. ,"Low",
Generates "neutral" and "high" signals.

When the vehicle height sensor 7 generates a "low" signal,
The vehicle height sensor 7 gives an operation signal to the compressor 8 and the air supply / exhaust solenoid valve 10 to supply air from the compressor 8 into the main chamber 4 and the sub chamber 5 of the air suspension 1 to raise the vehicle height.

When the vehicle height sensor 7 generates a "high" signal,
The controller 14 gives an operation signal to the exhaust solenoid valve 9 and the supply / exhaust solenoid valve 10 to exhaust the air in the main chamber 4 and the sub chamber 5 of the air suspension 1 to lower the vehicle height.

In this way, the controller 14 automatically adjusts the vehicle height to a predetermined value by using the "low" and "high" signals of the vehicle height sensor 7 as vehicle height adjustment request signals.

On the other hand, when adjusting the spring constant of the air suspension 1, the controller 14 gives an operation signal to the actuator 6 when the traveling state of the vehicle is predicted to be in a transient state from the detection signal of the traveling state sensor 15, and the air suspension 1
The main chamber 4 and the sub chamber 5 are cut off from each other to increase the spring constant and harden the spring characteristics of the air suspension 1. The transitional state of the vehicle is a transitional state in which the traveling state of the vehicle changes. Specifically, the state of the vehicle starting, accelerating, decelerating, turning (during steering), etc. It was when.

When the transient state has passed, the controller 14 establishes communication between the main chamber 4 and the sub chamber 5 and restores them to the original state.

Next, a case will be described in which the traveling state becomes a transitional state, and the time when the spring constant of the air suspension 1 should be adjusted and the time when the vehicle height is higher than the target vehicle height and the main chamber 4 should be exhausted at the same time. .

When the vehicle height sensor 7 generates the signal "neutral", it is not necessary to adjust the vehicle height, and the spring constant of the air suspension 1 is adjusted.

When it is necessary to adjust the spring constant while the controller 14 operates the exhaust solenoid valve 9 to exhaust the main chamber 4 when the vehicle height sensor 7 is issuing a "high" signal, the exhaust gas is exhausted. The operation of the solenoid valve 9 is stopped and interrupted, and the spring constant of the air suspension 1 is adjusted in preference to the vehicle height adjustment. The vehicle height adjustment is restarted when the request for the spring constant adjustment is canceled.

The vehicle height sensor 7 is issuing a "low" signal, and when the controller 14 operates the compressor 8 to supply air to the main chamber 4 of the air suspension 1, it is necessary to adjust the spring constant of the air suspension 1. in case of,
The spring constant is adjusted without interrupting the operation of the compressor 8. That is, the vehicle height adjustment and the spring constant adjustment are performed in parallel.

It should be noted that high-pressure air is stored in the main tank 11, the tank solenoid valve 12 is opened to increase the vehicle height, and air is supplied from the main tank 11 to the main chamber 4 for a predetermined time, and then the tank solenoid valve 12 is opened. Close
Air is supplied from the compressor 8 to the main room 4. If the pressure in the main tank 11 is equal to or lower than the set pressure after the vehicle height adjustment is completed, the tank solenoid valve 12 is opened to supply high pressure air from the compressor 8 to the main tank 11 to maintain the pressure in the main tank 11. To do. As a result, it is possible to reduce the chances that the vehicle height adjustment of the air suspension and the spring constant adjustment overlap, and it is possible to shorten the adjustment time for raising the vehicle height.

As described above, the control device for the air suspension 1 according to the present embodiment, when exhausting the air from the main chamber 4 of the air suspension 1, gives priority to the running state sensor 15 over the vehicle height adjustment.
The spring constant of the air suspension 1 is adjusted according to the running state of the vehicle detected by. That is, when the running state becomes a transitional state and the spring constant of the air suspension 1 should be adjusted and the vehicle height is higher than the target vehicle height and the main chamber 4 should be exhausted at the same time, , Even if the main chamber 4 and the sub chamber 5 are shut off by the actuator 6,
Since the air in the main chamber 4 is exhausted by exhaust air, the spring characteristics of the air suspension cannot be hardened.
The exhaust of the main chamber 4 is stopped and the spring constant of the air suspension 1 is adjusted to make the spring characteristics of the air suspension 1 firm. Further, when air is supplied to the main chamber 4 of the air suspension 1, control for adjusting the spring constant of the air suspension 1 according to the traveling state of the vehicle detected by the traveling state sensor 15 and the vehicle height sensor 7 are performed. The air suspension 1 is controlled on the basis of the detection signal from the vehicle to control the vehicle height in parallel. That is, since the spring characteristic of the air suspension 1 tends to become hard when air is supplied to the main chamber 4, even if air is supplied to the main chamber 4 and the main chamber 4 and the sub chamber 5 are shut off at the same time. Since the spring constant of No. 4 can be increased, these adjustments are performed in parallel without prioritizing the spring constant adjustment and the vehicle height adjustment.

Therefore, according to the present embodiment, when the vehicle height adjustment of the air suspension 1 and the spring constant adjustment are performed at the same time, the spring constant adjustment of the air suspension 1 is performed only when the main chamber 4 is exhausted. By giving priority to, the number of cases in which the adjustment control of the spring constant of the air suspension is prioritized over the adjustment control of the vehicle height is reduced, and as a whole, the vehicle height adjustment time can be made earlier than in the past. In addition, the spring constant adjustment control is prioritized when exhausting the main chamber, and the spring constant adjustment control is performed in parallel with the vehicle height adjustment control during air supply. Since the adjustment control of the spring constant in the state can be performed at an early stage, the function of the suspension can be effectively exerted, for example, reducing the vibration of the vehicle body, softening the impact, and improving the riding comfort.

[Advantages of the Invention] As described above, the air suspension control device of the present invention is designed to control the spring constant prior to the vehicle height adjustment during the transient state of running when the main chamber is exhausted. As only, by adjusting the spring constant during air supply to the main room in parallel with the vehicle height adjustment control,
The case where the spring constant adjustment is prioritized over the vehicle height adjustment becomes smaller than in the conventional case, and as a whole, the vehicle height adjustment time can be made earlier than in the conventional case. Further, in any case, since the adjustment control of the spring constant in the transient state can be performed at an early stage, for example, the fluctuation of the vehicle body can be reduced to reduce the impact,
The functions of the suspension can be effectively exhibited such as improving the riding comfort.

[Brief description of drawings]

The drawing is a block diagram for explaining an embodiment of the present invention. 1 ... Air suspension, 4 ... Main room, 5 ... Sub-room,
6 ... actuator, 7 ... vehicle height sensor, 8 ... compressor, 9 ... exhaust solenoid valve, 10 ... supply / exhaust solenoid valve, 14 ... controller, 15 ...
Running condition sensor.

Claims (1)

[Scope of utility model registration request] 1. An air suspension that controls a spring constant in response to air communication and interruption of air between a main chamber and a sub chamber and changes vehicle height in response to air supply and exhaust to the main chamber. The running state sensor that detects the running state of the vehicle, the vehicle height sensor that detects the vehicle height, and the air suspension is controlled based on the detection signal from the vehicle height sensor to adjust the vehicle height, and the running state In a control device for an air suspension, which comprises a controller that changes a spring constant based on a detection signal of a sensor, when the air in the main chamber is exhausted, the vehicle height detected by the running state sensor is prioritized over the vehicle height adjustment. The spring constant of the air suspension is adjusted according to the running state, and when air is supplied to the main chamber, the air suspension is adjusted according to the running state of the vehicle detected by the running state sensor. Control for adjusting the spring constant of the suspension and control for adjusting the vehicle height by controlling the air suspension based on the detection signal from the vehicle height sensor are performed in parallel. apparatus.