Vehicle height adjustment apparatus
A vehicle height adjustment apparatus includes a spring, an adjustor, a storage chamber, a pump, and a flow path switching unit. The adjustor includes an accommodation chamber which accommodates liquid, and adjusts the length of the spring according to the amount of liquid in the accommodation chamber. The pump includes a cylinder. The flow path switching unit includes a first communication path through which the inside of the cylinder communicates with the storage chamber, a second communication path through which the inside of the cylinder communicates with the accommodation chamber, and a third communication path through which the accommodation chamber communicates with the storage chamber. The flow path switching unit switches the flow path of the liquid according to an amount of electric current supplied to the flow path switching unit.
1. A vehicle height adjustment apparatus comprising:
a spring having one end supported at a side of a body of a vehicle and another end supported at a side of a wheel of the vehicle;
an adjustor that comprises an accommodation chamber which accommodates liquid, and adjusts a length of the spring according to an amount of liquid in the accommodation chamber;
a storage chamber that stores the liquid;
a pump that comprises a cylinder and is configured to suction the liquid in the storage chamber into the cylinder when a relative distance between the body and the wheel increases, and discharge the liquid in the cylinder when the relative distance between the body and the wheel decreases; and
a flow path switching unit that comprises a first communication path through which an inside of the cylinder communicates with the storage chamber; a second communication path through which the inside of the cylinder communicates with the accommodation chamber; and a third communication path through which the accommodation chamber communicates with the storage chamber, and switches a flow path of the liquid between the first communication path, the second communication path and the third communication path according to an amount of electric current supplied to the flow path switching unit.
2. The vehicle height adjustment apparatus according to claim 1 ,
wherein the flow path switching unit comprises a second communication path opening and closing valve that is disposed on the second communication path, allows the liquid to flow into the accommodation chamber from the cylinder, and prevents the liquid from flowing into the cylinder from the accommodation chamber, and
wherein according to the amount of the electric current supplied to the flow path switching unit, the flow path switching unit switches between a state in which the first communication path is opened, and the third communication path is closed; a state in which the first communication path and the third communication path are closed; and a state in which the first communication path is closed, and the third communication path is opened.
3. The vehicle height adjustment apparatus according to claim 2 ,
wherein the flow path switching unit further comprises:
a solenoid that comprises an operation rod that protrudes from a case by an amount that is changed according to the amount of the electric current supplied to the flow path switching unit and a plate-like valve which is attached to the operation rod;
a valve body that rests on a resting surface; and
a push rod which is pushed by the operation rod of the solenoid so that the push rod moves,
wherein when the amount of protrusion of the operation rod of the solenoid from the case is greater than or equal to a first reference amount, the operation rod protrudes to a position in which the valve closes the first communication path, and
wherein when the amount of protrusion of the operation rod of the solenoid from the case is greater than or equal to a second reference amount which is predetermined to be greater than the first reference amount, the push rod is pushed by the operation rod, pushes the valve body so that the valve body moves away from the resting surface, and thereby the third communication path is opened.
4. The vehicle height adjustment apparatus according to claim 3 ,
wherein when the amount of protrusion of the operation rod of the solenoid from the case is less than the first reference amount, the flow path switching unit opens the first communication path, and guides the liquid, which is discharged by the pump, to the storage chamber.
5. The vehicle height adjustment apparatus according to claim 4 ,
wherein the push rod receives a pressure of the liquid discharged by the pump so that the push rod moves in a direction to push the valve body.
6. The vehicle height adjustment apparatus according to claim 5 ,
wherein a pressure receiving area of the push rod is equal to a pressure receiving area of the valve body, or the pressure receiving area of the valve body is larger than the pressure receiving area of the push rod, with the pressure receiving area of the push rod receiving a force that is applied to the push rod in the direction to push the valve body due to that the liquid is discharged by the pump, and with the pressure receiving area of the valve body receiving a force that is applied to the valve body in contact with the resting surface in a direction opposite to the direction to push the valve body.
7. The vehicle height adjustment apparatus according to claim 3 ,
wherein the push rod receives a pressure of the liquid discharged by the pump so that the push rod moves in a direction to push the valve body.
8. The vehicle height adjustment apparatus according to claim 7 ,
wherein a pressure receiving area of the push rod is equal to a pressure receiving area of the valve body, or the pressure receiving area of the valve body is larger than the pressure receiving area of the push rod, with the pressure receiving area of the push rod receiving a force that is applied to the push rod in the direction to push the valve body due to that the liquid is discharged by the pump, and with the pressure receiving area of the valve body receiving a force that is applied to the valve body in contact with the resting surface in a direction opposite to the direction to push the valve body.
9. The vehicle height adjustment apparatus according to claim 1 ,
wherein the flow path switching unit further comprises:
a solenoid that comprises an operation rod that protrudes from a case by an amount that is changed according to the amount of the electric current supplied to the flow path switching unit and a plate-like valve which is attached to the operation rod;
a valve body that rests on a resting surface; and
a push rod which is pushed by the operation rod of the solenoid so that the push rod moves,
wherein when the amount of protrusion of the operation rod of the solenoid from the case is greater than or equal to a first reference amount, the operation rod protrudes to a position in which the valve closes the first communication path, and
wherein when the amount of protrusion of the operation rod of the solenoid from the case is greater than or equal to a second reference amount which is predetermined to be greater than the first reference amount, the push rod is pushed by the operation rod, pushes the valve body so that the valve body moves away from the resting surface, and thereby the third communication path is opened.
10. The vehicle height adjustment apparatus according to claim 9 ,
wherein when the amount of protrusion of the operation rod of the solenoid from the case is less than the first reference amount, the flow path switching unit opens the first communication path, and guides the liquid, which is discharged by the pump, to the storage chamber.
11. The vehicle height adjustment apparatus according to claim 10 ,
wherein the push rod receives a pressure of the liquid discharged by the pump so that the push rod moves in a direction to push the valve body.
12. The vehicle height adjustment apparatus according to claim 11 ,
wherein a pressure receiving area of the push rod is equal to a pressure receiving area of the valve body, or the pressure receiving area of the valve body is larger than the pressure receiving area of the push rod, with the pressure receiving area of the push rod receiving a force that is applied to the push rod in the direction to push the valve body due to that the liquid is discharged by the pump, and with the pressure receiving area of the valve body receiving a force that is applied to the valve body in contact with the resting surface in a direction opposite to the direction to push the valve body.
13. The vehicle height adjustment apparatus according to claim 9 ,
wherein the push rod receives a pressure of the liquid discharged by the pump so that the push rod moves in a direction to push the valve body.
14. The vehicle height adjustment apparatus according to claim 13 ,
wherein a pressure receiving area of the push rod is equal to a pressure receiving area of the valve body, or the pressure receiving area of the valve body is larger than the pressure receiving area of the push rod, with the pressure receiving area of the push rod receiving a force that is applied to the push rod in the direction to push the valve body due to that the liquid is discharged by the pump, and with the pressure receiving area of the valve body receiving a force that is applied to the valve body in contact with the resting surface in a direction opposite to the direction to push the valve body.