# US 5,341,777 A · Valve operation control system

> Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt

- Number: US 5,341,777 A
- Document ID: US5341777A
- Status: Granted
- Kind: A
- Application number: 08/010,884
- Filed: 1993-01-29
- Granted: 1994-08-30
- Earliest claimed: 1992-01-30
- Assignees: Aisin Seiki Kabushiki Kaisha
- Inventors: Yasushi Miura; Kongo Aoki
- Web page: https://patentgrep.com/patent/US5341777A

## CPC

- F01L 1/34406: {the helically teethed sleeve being located in the camshaft driving pulley}
- F01L 2810/04: Reducing noise
- F01L: CYCLICALLY OPERATING VALVES FOR MACHINES OR ENGINES

## Abstract

A valve operation control system for an internal combustion engine having a cam-shaft and a crank-shaft has an adjusting device for adjusting a phase difference between the cam-shaft and the crank-shaft by being supplied with hydraulic pressure, a driving device integrated with the adjusting device and having an oil pump driven by the cam-shaft and a hydraulic pressure line between the oil pump and the adjusting device, and a hydraulic pressure control device disposed in the hydraulic pressure line for regulating the hydraulic pressure to be supplied to the adjusting device.

## Claims

### Claim 1

A valve operation control system for an internal combustion engine having a cam-shaft and a crank-shaft, comprising:
a timing gear driven by the crank-shaft;
a transmitting member connected to the cam-shaft; and
means for adjusting a phase difference between the cam-shaft and the crank-shaft, the means for adjusting including a pump having an inlet port and an outlet port, a pressure chamber disposed between the inlet port and the outlet port of the pump, a piston associated with the timing gear and the transmitting member in such a manner that movements of the piston in opposite directions respectively establish an increase and a decrease of the phase difference between the cam-shaft and the crank-shaft, one side of the piston being exposed to the pressure chamber, biasing means for biasing the piston toward the pressure chamber, a passage provided between the inlet port and outlet port of the pump and bypassing the pressure chamber, and control means for opening and closing the passage.

### Claim 2 (depends on 1)

A valve operation control system in accordance with claim 1, wherein the control means includes an electric controller and an electro-magnetic valve which opens and closes the passages on the basis of a commend from the electric controller.

### Claim 3 (depends on 1)

A valve operation control system in accordance with claim 1 further comprising a first sensor for detecting an angular position of the cam-shaft and a second sensor for detecting an angular position of the crank-shaft, wherein the command issued from the electric controller depends on results of the first sensor and the second sensor.

### Claim 4 (depends on 1)

A valve operation control system in accordance with claim 1, wherein the biasing means is a spring.