Valve apparatus for controlling hydraulic pressure for a clutch or a brake and method for controlling hydraulic pressure
US6499577B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | May 24, 2001 |
| Grant date | Dec 31, 2002 |
| Priority date | — |
| Expiry date | May 24, 2021 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T137/86847
- WIPO fieldMechanical elements
- WIPO sectorMechanical engineering
Abstract
Hydraulic pressure is controlled, which has such advantages that a generation of peak pressure (shoot pressure) can be lowered, mis-operation due to biting of particles can be reduced, or the cost thereof can be reduced. First, a large amount inflow command current is supplied to a proportional solenoid from a time point t1 to a time point t2. Consequentially, pilot pressure rises in a pilot pressure receiving chamber, so that a pressure control valve allows a large amount of hydraulic fluid to flow in a clutch or brake cylinder. At this time, potential detected by a pressure switch becomes zero level. Next, at the time point t2, a filling command small current is supplied to the proportional solenoid, thereby decreasing the amount of hydraulic fluid, which flows from an input port to an output port. This state is maintained from the time point t2 to a time point t3. At the termination of filling, peak pressure will not be generated, and a speed-changing shock in a clutch will not be generated, so that smooth switching can be accomplished.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.