Engine control circuit
AssigneeMcGraw-Edison Company
InventorsDennis A. Luhn, Daniel A. Norrick
Life of this patent
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Abstract
A control system for an internal combustion engine is described which allows the engine to be started and stopped while unloaded. The invention incorporates the mechanical linkage operated by a solenoid to control a valve at the interior of the engine and an electronic circuit incorporating one or more time delay relays. The invention provides a means of reducing or eliminating the source of vibration resulting from the starting and stopping of a single cylinder diesel engine. Several embodiments are described including one incorporating an integrated circuit timer and one incorporating two time delay relays.
Claims18
In an internal combustion engine having a combustion chamber, an exhaust valve, a drive shaft, a cam shaft driven by said drive shaft, and a rocker arm linkage for transmitting the rotation of said cam shaft to operate said exhaust valve, an unloading circuit, comprising:
- (a) an electrical solenoid;
- (b) camming means for operating said rocker arm linkage to hold said exhaust valve open in response to the energization of said electrical solenoid;
- (c) an electrical time delay circuit for energizing said solenoid for a pre-selected time interval, said electrical time delay circuit including a first time delay relay for energizing said solenoid during the start-up and shut-down of said engine, and a second time delay relay for delaying the energization of said first time delay relay during the shut-down of said engine;
- and
- (d) switching means for energizing said electrical time delay circuit during the shut-down of said engine, said switching means including means for energizing said electrical circuit during the start-up and shut-down of said engine,
- whereby said engine on slowing down is allowed to rundown for a first pre-selected time interval while loaded and for a second pre-selected time interval while unloaded.
A control system for an internal combustion engine of a type having a combustion chamber and a valve for controlling the flow of fluid between said combustion chamber and the atmosphere, comprising:
- (a) means for opening and closing said valve in response to the rotation of a control shaft to a pre-selected position;
- (b) solenoid means for rotating said control shaft to said pre-selected position upon energization of an electrical solenoid;
- (c) monostable means for energizing said solenoid for a pre-selected time interval, said monostable means including a reset terminal, a trigger terminal and an output terminal;
- (d) a first relay which is energized in response to the output terminal of said monostable means and which includes a plurality of electrical contacts which are opened and closed in response to the operation of said relay, said electrical contacts including a first contact set which is connected to said solenoid such that said solenoid is energized when said monostable means is triggered and de-energized when said monstable means is reset, and a second contact set which are normally closed when said relay is not energized;
- (e) three-position electrical switch means for supplying electrical power to trigger said monostable means when said switch means is in a start position and for supplying electrical power to reset said monostable means when said switch is in a run position;
- and
- (f) energy storage means, electrically in parallel with said monostable means, for storing power to operate said monostable means and to trigger said monostable means when said three-position switch means is moved between said run position and a position intermediate said start and said run positions, whereby said solenoid means is operated when said three-position switch means is in its start position, said solenoid means is de-energized when said three-position switch is in its run position and said solenoid means is re-energized when said three-position switch is between its start and its run positions after being in its run position.
In an internal combustion engine having a combustion chamber, and a valve for controlling the flow of combustion gases from said combustion chamber to the atmosphere, a control system comprising:
- (a) camming means for opening said valve in response to the rotation of a control shaft to a pre-selected position;
- (b) a solenoid and solenoid means for rotating said control shaft to said pre-selected position upon the energization of said solenoid, said solenoid having an electrical armature and a plunger operated in response to the energization of said armature, and said solenoid means including a bell crank connecting said plunger with said control shaft;
- (c) a time delay circuit for energizing said solenoid for a pre-selected time interval;
- and
- (d) electrical switch means for supplying electrical power to said time delay circuit when said engine is shutdown,
- whereby said engine is shut down with said combustion chamber vented to the atmosphere for a pre-selected period of time.
Dependencies are inferred from the claim text.