Topic
Compression release
About: Compression release is a research topic. Over the lifetime, 213 publications have been published within this topic receiving 2451 citations.
Papers published on a yearly basis
Papers
Patent•
30 Apr 1985
TL;DR: In this paper, a process and apparatus for the compression release retarding of a multi-cylinder four cycle internal combustion engine is described, which includes hydraulic means driven by the engine pushtubes which produce a timed hydraulic pulse adapted to open the exhaust and intake valves at the proper time.
Abstract: Process and apparatus for the compression release retarding of a multi-cylinder four cycle internal combustion engine are provided. The process provides a compression release event for each cylinder during each revolution of the engine crankshaft. In accordance with the process, the normal motion of the exhaust and intake valves is inhibited and the exhaust valves are opened briefly at each time the engine piston approaches the top dead center position. The intake valves are opened after each opening of the exhaust valves. The apparatus includes hydraulic means driven by the engine pushtubes which produce a timed hydraulic pulse adapted to open the exhaust and intake valves at the proper time. Hydraulically actuated means are provided to disable the valve crosshead or rocker arm so as to inhibit the normal motion of the valves. Alternatively, timed signals from an electronic controller actuate solenoid valves to control a hydraulic pulse which opens the valves. Solenoid means may also be provided to open the valves mechanically.
102 citations
Patent•
2 Aug 1996TL;DR: In this paper, an inernal combustion engine (10) has engine cylinder intake and exhaust valves (30, 60) that are operated by intake/exhaust cams (40, 70) via hydraulic linkages (54, 84).
Abstract: An inernal combustion engine (10) has engine cylinder intake and exhaust valves (30, 60) that are operated by intake and exhaust cams (40, 70) via hydraulic linkages (54, 84). The hydraulic linkages (54, 84) have selective lost motion that allow selective modification of the openings and closings of the engine cylinder valves (30, 60). These modifications may include complete omission of all response to particular lobes on the cams (40, 70). The hydraulic linkages may be interconnected so that some intake valve openings are produced by an exhaust cam lobe and/or some exhaust valve openings are produced by an intake cam lobe. The linkages and linkage interconnections are preferably controlled electronically. The engine is preferably operable in either four-cycle positive power mode or two-cycle compression release engine braking mode.
91 citations
Patent•
23 Dec 1997
TL;DR: In this article, an apparatus and method for effectuating multi-cycle engine braking is presented, which controls the operation of the engine valves to permit more than one compression release event during a single engine operating cycle.
Abstract: An apparatus and method for effectuating multi-cycle engine braking is disclosed. The present invention controls the operation of the engine valves to permit more than one compression release event during a single engine operating cycle. The apparatus includes an assembly for operating at least one exhaust valve of an engine cylinder during a positive power operation. The apparatus further includes an assembly for operating at least one intake valve of the engine cylinder. The apparatus further including an assembly for operating the at least one exhaust valve during an engine braking operation.
66 citations
Patent•
21 Sep 1990TL;DR: In this article, an engine retarding system of a gas compression release type is provided for an engine equipped with a high pressure hydraulic fluid supply system, which comprises an hydraulically driven exhaust valve actuator, a solenoid actuated servo valve controlling the flow of high-pressure hydraulic fluid from the supply to the actuator and an electronic controller which provides a signal to operate the soleneoid as a function of the engine speed and crankshaft position.
Abstract: An engine retarding system of a gas compression release type is provided for an engine equipped with a high pressure hydraulic fluid supply system. The retarder comprises an hydraulically driven exhaust valve actuator, a solenoid actuated servo valve controlling the flow of high pressure hydraulic fluid from the supply to the actuator and an electronic controller which provides a signal to operate the solenoid as a function of the engine speed and crankshaft position.
60 citations
Patent•
20 Mar 1996TL;DR: In this article, the stroke lengths of the engine cylinder valves (20, 30) are automatically adjusted for various engine operating conditions using feedback loops that include sensors (64) for detecting the amount of opening of each engine cylinder valve whose stroke length is to be controlled in this manner.
Abstract: A camless internal combustion engine has electronically or computer controlled, electrically operated hydraulic actuators (40, 50) for selectively opening the engine cylinder valves (20, 30). The engine is capable of operating in either positive power mode or compression release engine braking mode. The pressure of the hydraulic fluid available for application to the hydraulic actuators is automatically adjusted from a relatively low pressure during positive power mode to a relatively high pressure during compression release engine braking mode. The stroke lengths of the engine cylinder valves (20, 30) may be automatically adjusted for various engine operating conditions using feedback loops that include sensors (64) for detecting the amount of opening of each engine cylinder valve (20, 30) whose stroke length is to be controlled in this manner. The shapes of the valve opening and closing trajectories as a function of engine crank angle may similarly be varied in many other respects.
57 citations
Related Topics (5)
Performance Metrics
| Year | Papers |
|---|---|
| 2021 | 4 |
| 2020 | 7 |
| 2019 | 6 |
| 2018 | 4 |
| 2017 | 5 |
| 2016 | 5 |