Hydraulic vehicle clutch system and method

Patent metadata

Field	Value
Publication number	US-9611906-B2
Application number	US-83284907-A
Country	US
Kind code	B2
Filing date	Aug 2, 2007
Priority date	Aug 2, 2007
Publication date	Apr 4, 2017
Grant date	Apr 4, 2017

Abstract

A hydraulic system for a vehicle clutch assembly can include a pump and a purge valve for regulating hydraulic pressure supplied to the clutch. The hydraulic pressure at the pump can be set to a value higher than the operating pressure for the clutch. The purge valve can be configured to purge hydraulic pressure from the hydraulic system so that an optimum, controllable, and/or pre-determined operating pressure can be supplied to the clutch. The system can be configured to provide accurate control of the clutch(es), continuous cooling capacity to the hydraulic system components, lateral torque control when two separate hydraulic circuits are used, weight and cost reduction of the vehicle clutch, as well as other vehicle functions and characteristics.

First claim

What is claimed is:

1. An apparatus for transferring a torque from a vehicle drive train to a wheel of a vehicle, the apparatus comprising:
a first clutch having a first driven part and a first driving part;
a second clutch having a second driven part and a second driving part;
a hydraulic system configured to actuate the first clutch and the second clutch by placing the first driven part into engagement with the first driving part and by placing the second driven part into engagement with the second driving part, the hydraulic system including:
a first cylinder,
a second cylinder,
a first piston movably received in the first cylinder and configured to move the first driven part into engagement with the first driving part when an operating hydraulic fluid pressure is supplied to the first piston,
a second piston movably received in the second cylinder and configured to move the second driven part into engagement with the second driving part when an operating hydraulic fluid pressure is supplied to the second piston,
a pump in fluid communication with the first piston and the second piston and configured to supply an output hydraulic fluid pressure, and
a purge valve connected to a junction that is located between the pump and each of the first piston and the second piston and connected to the pump in parallel fluid communication with each of the first piston and the second piston, the purge valve is a variable-type linear solenoid valve that has a fully closed position, a fully open position, and a plurality of intermediate positions such that fluid flow through the purge valve is prevented if the purge valve is in the fully closed position, fluid flows through the purge valve at a first flow rate if the purge valve is in the fully open position, and fluid flows through the purge valve at one of a plurality of intermediate flow rates if the purge valve is in a respective one of the intermediate positions, where each of the intermediate flow rates is less than the first flow rate; and

a controller in communication with the hydraulic system and configured to control each of the pump and purge valve to provide a desired hydraulic pressure to the first piston and the second piston.

2. The apparatus of claim 1 , wherein the controller includes means for causing the pump to operate at a first output pressure that is greater than the operating hydraulic pressure of the piston, and for causing the purge valve to reduce the first output pressure of the hydraulic fluid to the operating hydraulic pressure before the hydraulic fluid reaches the first piston and the second piston when the pump is operating at the first output pressure.

3. The apparatus of claim 1 , wherein the controller includes means for causing the pump to operate at a second output pressure when the first piston and the second piston are not actuated such that the hydraulic fluid continues moving through the hydraulic system such that the hydraulic fluid provides cooling to at least a portion of the apparatus.

4. The apparatus of claim 1 , wherein the controller is configured to operate the pump at a second output pressure when the first piston and the second piston are not actuated such that the hydraulic fluid continues moving through the hydraulic system such that the hydraulic fluid provides cooling to at least a portion of the apparatus.

5. An apparatus for transferring a torque from a vehicle drive train to at least one wheel of a vehicle, the apparatus being configured for use independently of an accumulator, the apparatus comprising:
a first clutch having a first driven part and a first driving part;
a second clutch having a second driven part and second driving part;
a hydraulic system configured to selectively actuate the first clutch and the second clutch together by placing the first driven part into engagement with the first driving part and by placing the second driven part into engagement with the second driving part, the hydraulic system including:
a first piston configured to move the first driven part into engagement with the first driving part to actuate the first clutch when a first operating hydraulic pressure is supplied to the first piston,
a second piston configured to move the second driven part into engagement with the second driving part to actuate the second clutch when a second hydraulic pressure is supplied to the second piston,
a pump configured to supply an output hydraulic pressure,
a purge valve connected to the pump in parallel with the first piston and the second piston, the purge valve includes a fully closed position, a fully open position, and an intermediate position located between the fully closed position and the fully open position,
a pump hydraulic line connected between the pump and a junction,
a valve line connected between the purge valve and the junction,
a first piston hydraulic line connected between the junction and the first piston, and
a second piston hydraulic line connected between the first piston hydraulic line and the second piston, wherein
each of the first piston hydraulic line and the second piston hydraulic line are devoid of a valve, and wherein
the hydraulic system is configured such that when the first clutch is actuated a first pump pressure of hydraulic fluid is substantially constant along the entire pump hydraulic line from the pump to the junction without use of the accumulator, and the hydraulic system is also configured such that when the first clutch is actuated a first piston pressure of hydraulic fluid is substantially the same along the entire first piston hydraulic line from the junction to the first piston without use of the accumulator; and

a controller in electrical communication with each of the pump and the purge valve and configured to control each of the pump and purge valve to provide a first desired hydraulic pressure to the first piston.

6. The apparatus of claim 5 , wherein the piston pressure of hydraulic fluid in the first piston hydraulic line is substantially equal to the first operating hydraulic pressure when the first clutch is actuated.

7. The apparatus of claim 5 , wherein the pump pressure of hydraulic fluid in the pump hydraulic line is greater than the first operating hydraulic pressure when the first clutch is actuated.

8. The apparatus of claim 5 , wherein the purge valve is a variable-type linear solenoid valve.

9. The apparatus of claim 5 , wherein the controller includes means for causing the pump to operate at a working output pump pressure that is greater than the first operating hydraulic pressure of the first piston, and for causing the purge valve to reduce pressure of the hydraulic fluid to the first operating hydraulic pressure before the hydraulic fluid reaches the first piston, when the first clutch is actuated.

10. The apparatus of claim 5 , wherein the controller includes means for causing the pump to operate at a standby output pump pressure when the first clutch is not actuated such that the hydraulic fluid continues moving through the hydraulic system and such that the hydraulic fluid provides at least one of cooling and lubrication to at least a portion of the apparatus.

11. A method for transmitting torque to a vehicle drive component, the method comprising:
providing a first vehicle clutch configured to transmit torque from a vehicle power unit to a first vehicle wheel when the first vehicle clutch is actuated;
providing a second vehicle clutch configured to transmit torque from a vehicle power unit to a second vehicle wheel when the second vehicle clutch is actuated;
providing a first hydraulic circuit including hydraulic fluid and in which a pump is connected by a pump line to a purge valve, an

Assignees

• Asano Tetsushi
• Honda Motor Co Ltd

Inventors

• Asano Tetsushi

Classifications

• F16D2500/70282

  Time · CPC title

• F16D2500/10412

  Transmission line of a vehicle · CPC title

• F16D48/02 Primary

  Control by fluid pressure · CPC title

• F16D25/123

  in view of cooling and lubrication · CPC title

• F16D2500/70252

  Clutch torque · CPC title