Measurement of transmission oil pressure by monitoring solenoid current
US6318182A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jun 4, 1999 |
| Grant date | Nov 20, 2001 |
| Priority date | — |
| Expiry date | Jun 4, 2019 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF16H2059/683
- WIPO fieldMechanical elements
- WIPO sectorMechanical engineering
Abstract
A method and apparatus for measuring hydraulic pressure in a solenoid valve includes coupling the solenoid valve with a voltage source and monitoring the input current rise characteristic as the solenoid valve moves between the open and closed positions. The rise characteristic indicates the amount of current needed to move the solenoid valve and changes when the solenoid changes positions. The current levels in the characteristic are taken at two different time periods and compared to determine whether the solenoid has shifted positions by the second time period. Because a greater amount of current is required to move the solenoid valve if the hydraulic pressure is high, the rise characteristic will change sooner if the pressure is low and later if the pressure is high. The hydraulic pressure can therefore be determined by comparing the two current levels and correlating them with pressure values. As a result, hydraulic pressure can be measured and monitored without requiring attachment of a separate pressure sensor on the solenoid valve.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.