Vehicle-height control system

Patent metadata

Field	Value
Publication number	US-10759249-B2
Application number	US-201716097869-A
Country	US
Kind code	B2
Filing date	Jun 8, 2017
Priority date	Jun 17, 2016
Publication date	Sep 1, 2020
Grant date	Sep 1, 2020

Abstract

A vehicle-height control system including a tank, a compressor, an actuator, and a valve between the tank and the compressor. The valve is closed to a state of a pressure medium supplier to the compressor-pressure supply state when a tank pressure has reached a threshold in a tank-pressure supply state in which the tank pressure is supplied to the actuator. In the compressor-pressure supply state, the tank pressure is kept at the threshold, and a pressure in the actuator is greater than the tank pressure. The threshold makes it difficult for a pressure differential in the valve to become greater than a valve-opening pressure differential, making it difficult for the valve to be opened in the compressor-pressure supply state. This system enables good supply of a pressure medium from the compressor to the actuator, avoiding a longer time for vehicle height control and achieving a shorter compressor operation time.

First claim

The invention claimed is:

1. A vehicle-height control system, comprising:
a vehicle-height control actuator provided so as to correspond to a wheel;
a pressure medium supplier comprising (i) a tank connected to the vehicle-height control actuator and configured to store a pressure medium in a state in which the pressure medium is pressurized, (ii) a compressor device comprising a compressor and an electric motor configured to drive the compressor, and (iii) a cut-off valve that is an electromagnetic valve provided between the tank and the compressor and comprising a solenoid;
a tank pressure sensor configured to measure a tank pressure that is a pressure of the pressure medium stored in the tank; and
a vehicle height controller configured to raise a vehicle height for the wheel by supplying the pressure medium from the pressure medium supplier to the vehicle-height control actuator by controlling the pressure medium supplier in response to a request for a raise of the vehicle height,
wherein the tank is connected via the cut-off valve to a connecting portion of a passage connecting a discharge portion of the compressor and the vehicle-height control actuator to each other,
wherein the vehicle height controller comprises a state switcher configured to switch a state of the pressure medium supplier from a tank-pressure supply state to a compressor-pressure supply state by closing the cut-off valve and actuating the electric motor, wherein the tank-pressure supply state is a state in which the pressure medium is supplied from the tank to the vehicle-height control actuator, and the compressor-pressure supply state is a state in which the pressure medium is supplied from the compressor device to the vehicle-height control actuator,
wherein the state switcher is configured to switch the state of the pressure medium supplier from the tank-pressure supply state to the compressor-pressure supply state based on a measured tank pressure that is a value measured by the tank pressure sensor in the tank-pressure supply state, and
wherein, the cut-off valve is configured to, while the pressure medium supplier is in the compressor-pressure supply state, be switched from a closed state to an open state by a force caused by a pressure differential when the pressure differential becomes greater than a valve-opening pressure differential for the cut-off valve, wherein the pressure differential is a value obtained by subtracting a pressure of the pressure medium on a side of the cut-off valve which is nearer to the tank than the compressor from a pressure of the pressure medium on a side of the cut-off valve which is nearer to the compressor than the tank.

2. The vehicle-height control system according to claim 1 , wherein the state switcher is configured to switch the state of the pressure medium supplier from the tank-pressure supply state to the compressor-pressure supply state when the measured tank pressure has lowered and reached a threshold value.

3. The vehicle-height control system according to claim 2 ,
wherein the vehicle height controller comprises an actuator pressure sensor configured to measure an actuator pressure that is a pressure of the pressure medium in the vehicle-height control actuator, and
wherein the state switcher comprises a threshold value determiner configured to determine the threshold value to a greater value when a measured actuator pressure that is a value measured by the actuator pressure sensor at a start of control for raising the vehicle height is high than when the measured actuator pressure is low.

4. The vehicle-height control system according to claim 2 , wherein the threshold value is determined based on the valve-opening pressure differential for the cut-off valve.

5. The vehicle-height control system according to claim 1 , wherein the vehicle height controller is configured to establish the tank-pressure supply state of the pressure medium supplier when a request for a raise of the vehicle height is issued.

6. The vehicle-height control system according to claim 1 ,
wherein the vehicle height controller is configured to turn the solenoid of the cut-off valve on in the tank-pressure supply state to open the cut-off valve, and
wherein the state switcher is configured to switch the cut-off valve from an open state to a closed state by turning the solenoid of the cut-off valve off when switching the state of the pressure medium supplier from the tank-pressure supply state to the compressor-pressure supply state.

7. The vehicle-height control system according to claim 1 ,
wherein the tank and the vehicle-height control actuator are connected to each other by a bypass passage that bypasses the cut-off valve and the compressor, and
wherein the vehicle height controller is configured to establish an OFF state of the solenoid of the cut-off valve and a closed state of the cut-off valve in any of the tank-pressure supply state and the compressor-pressure supply state.

8. A vehicle-height control system, comprising:
a vehicle-height control actuator provided so as to correspond to a wheel;
a pressure medium supplier comprising (i) a tank connected to the vehicle-height control actuator and configured to store a pressure medium in a state in which the pressure medium is pressurized, (ii) a compressor device comprising a compressor and an electric motor configured to drive the compressor, and (iii) a cut-off valve that is an electromagnetic valve provided between the tank and the compressor and comprising a solenoid;
a tank pressure sensor configured to measure a tank pressure that is a pressure of the pressure medium stored in the tank; and
a vehicle height controller configured to raise a vehicle height for the wheel by supplying the pressure medium from the pressure medium supplier to the vehicle-height control actuator by controlling the pressure medium supplier in response to a request for a raise of the vehicle height,
wherein the tank is connected via the cut-off valve to a connecting portion of a passage connecting a discharge portion of the compressor and the vehicle-height control actuator to each other,
wherein the vehicle height controller comprises a state switcher configured to switch a state of the pressure medium supplier from a tank-pressure supply state to a compressor-pressure supply state by closing the cut-off valve and actuating the electric motor, wherein the tank-pressure supply state is a state in which the pressure medium is supplied from the tank to the vehicle-height control actuator, and the compressor-pressure supply state is a state in which the pressure medium is supplied from the compressor device to the vehicle-height control actuator,
wherein the state switcher is configured to switch the state of the pressure medium supplier from the tank-pressure supply state to the compressor-pressure supply state based on a measured tank pressure that is a value measured by the tank pressure sensor in the tank-pressure supply state,
wherein the state switcher is configured to switch the state of the pressure medium supplier from the tank-pressure supply state to the compressor-pressure supply state when the measured tank pressure has lowered and reached a threshold value, and
wherein the threshold value is determined by subtracting a valve-opening pressure differential for the cut-off valve from a target pressure that is a pressure of the pressure medium in the vehicle-height control actuator in a case where the vehicle height has reached a target vehicle height.

Assignees

• Toyota Motor Co Ltd
• Aisin Seiki

Inventors

• Ohashi Hideki
• Tokumitsu Jun
• Kanda Ryo
• Tanaka Shogo
• Oishi Masaaki

Classifications

• B60G2500/204

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• B60G2500/2021

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• B60G17/0523 Primary

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