Four-cycle internal combustion engines with two-cycle compression release braking
AssigneeDiesel Engine Retarders, Inc.
InventorHaoran Hu
Life of this patent
Estimating the term…
Abstract
An internal combustion engine has engine cylinder intake and exhaust valves that are operated by intake and exhaust cams via hydraulic linkages. The hydraulic linkages have selective lost motions that allow selective modification of the openings and closings of the engine cylinder valves. These modifications may include complete omission of all response to particular lobes on the cams. 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.
Claims32
An internal combustion engine comprising;
- an intake valve associated with a cylinder of said engine;
- an exhaust valve associated with said cylinder;
- an intake cam having at least one lobe synchronized with possible openings of said intake valve;
- an exhaust cam having a plurality of lobes synchronized with possible openings of said exhaust valve;
- a first hydraulic linkage containing hydraulic fluid operatively coupled between said intake cam and said intake valve for selectively responding to said intake cam lobe by causing said intake valve to open;
- a second hydraulic linkage containing hydraulic fluid operatively coupled between said exhaust cam and said exhaust valve for selectively responding to said exhaust cam lobes by causing said exhaust valve to open;
- a first hydraulic fluid control for selectively controlling hydraulic fluid pressure in said first hydraulic linkage to selectively modify the openings of said intake valve in response to said intake cam lobe;
- and
- a second hydraulic fluid control for selectively controlling hydraulic fluid pressure in said second hydraulic linkage to selectively modify the openings of said exhaust valve in response to said exhaust cam lobe.
An internal combustion engine comprising:
- an intake valve associated with a cylinder of said engine;
- an exhaust valve associated with said cylinder;
- an intake cam having at least one lobe synchronized with possible openings of said intake valve;
- an exhaust cam having a plurality of lobes synchronized with possible openings of said exhaust valve;
- a first hydraulic linkage including a first master piston reciprocated by said intake cam lobe, a first slave piston for reciprocating to open said intake valve, a first hydraulic fluid coupling between said first master piston and said first slave piston for selectively causing said first slave piston to reciprocate in response to reciprocation of said first master piston, and a first electrically controlled valve for selectively releasing hydraulic fluid pressure from said first coupling to modify the response of said first slave piston to reciprocation of said first master piston;
- a second hydraulic linkage including a second master piston reciprocated by said exhaust cam lobes, a second slave piston for reciprocating to open said exhaust valve, a second hydraulic fluid coupling between said second master piston and said second slave piston for selectively causing said second slave piston to reciprocate in response to reciprocation of said second master piston, and a second electrically controlled valve for selectively releasing hydraulic fluid pressure from said second coupling to modify the response of said second slave piston to reciprocation of said second master piston, said second valve being selectively operable to cause said exhaust valve to remain completely closed in response to any first one of said exhaust cam lobes and to open in response to any second one of said exhaust cam lobes;
- and
- electronic control circuitry for controlling said first and second valves.
Dependencies are inferred from the claim text.