Claims
- 1. A system for injecting lubricating oil into an engine prior to startup of the engine, comprising:
- (a) a substantially cylindrical housing having means defining an inlet at a first end thereof, said housing defining an interior chamber of preselected variable volumetric size for containing a quantity of lubricating oil;
- (b) conduit means for operatively interconnecting said inlet with the engine;
- (c) a piston slideably disposed within said housing and including a surface thereon further defining said interior chamber;
- (d) spring means interposed between said piston and the second end of said housing and biasing said piston toward a first axial position near said first end of said housing;
- (e) latch means for selectively holding said piston in a second position near said second end of said housing;
- (f) a solenoid having the plunger thereof operatively connected to said latch means for selectively releasing said latch means;
- (g) electrical means for operatively interconnecting said solenoid and the ignition switch of said engine for selectively energizing said solenoid in response to operation of said ignition switch; and
- (h) a time delay switching means operatively interconnecting said solenoid and said electrical means for selectively delaying the energizing of said solenoid in response to operation of said ignition switch.
- 2. The system as recited in claim 1 wherein said time delay switching means includes a thermal delay switch.
- 3. The system for injecting lubricating oil into an engine prior to startup of the engine, comprising:
- (a) a first housing portion having means defining an inlet at a first end thereof and an outlet at a second end thereof;
- (b) a solenoid including a coil and plunger disposed within said first housing portion and defining a central passageway through said coil from said inlet to said outlet, said plunger disposed for axial movement within said passageway between an extended position and a retracted position in response to energization of said coil of said solenoid;
- (c) conduit means for operatively interconnecting said inlet of said first housing portion with the crankcase of the engine;
- (d) a spring loaded check valve disposed at the outlet of said first housing portion, said check valve having a closed position and an open position;
- (e) means on said plunger for engaging said check valve whereby said check valve is moved between said closed position and said open position in response to movement of said plunger;
- (f) a substantially cylindrical second housing portion having means defining an inlet at a first end thereof, said second housing portion defining an interior chamber of preselected variable volumetric size for containing a quantity of lubricating oil;
- (g) a piston slideably disposed within said second housing portion and including a surface thereon further defining said interior chamber;
- (h) spring means interposed between said piston and the second end of said second housing portion and biasing said piston toward a first axial position near said first end of said second housing portion;
- (i) electrical means for operatively interconnecting said solenoid and the ignition switch of said engine for selectively energizing said solenoid in response to operation of said ignition switch; and
- (j) a time delay switching means operatively interconnecting said solenoid and said electrical means for selectively delaying the energizing of said solenoid in response to operation of said ignition switch.
- 4. The system as recited in claim 3 wherein said time delay switching means includes a thermal delay switch.
- 5. A system for injecting lubricating oil into an engine following shutdown of the engine, comprising:
- (a) a substantially cylindrical housing having means defining an inlet at a first end thereof, said housing defining an interior chamber of preselected variable volumetric size for containing a quantity of lubricating oil;
- (b) conduit means for operatively interconnecting said inlet with the engine;
- (c) a piston slidably disposed within said housing and including a surface thereon further defining said interior chamber;
- (d) spring means interposed between said piston and the second end of said housing and biasing said piston toward a first axial position near said first end of said housing;
- (e) latch means for selectively holding said piston in a second position near said second end of said housing;
- (f) a solenoid having the plunger thereof operatively connected to said latch means for selectively releasing said latch means;
- (g) electrical means for operatively interconnecting said solenoid and the ignition switch of said engine for selectively energizing said solenoid in response to operation of said ignition switch; and
- (h) a control circuit operatively interconnecting said solenoid and said electrical means and including a normally open time delay switching means and a normally closed electrical relay for selectively delaying the energizing of said solenoid in response to switchoff of said ignition switch upon shutdown of said engine.
- 6. The system as recited in claim 5 wherein said time delay switching means includes a thermal delay switch.
- 7. A system for injecting lubricating oil into an engine following shutdown of the engine, comprising:
- (a) a first housing portion having means defining an inlet at a first end thereof and an outlet at a second end thereof;
- (b) a solenoid including a coil and plunger disposed within said first housing portion and defining a central passageway through said coil from said inlet to said outlet, said plunger disposed for axial movement within said passageway between an extended position and a retracted position in response to energization of said coil of said solenoid;
- (c) conduit means for operatively interconnecting said inlet of said first housing portion with the crankcase of the engine;
- (d) a spring loaded check valve disposed at the outlet of said first housing portion, said check valve having a closed position and an open position;
- (e) means on said plunger for engaging said check valve whereby said check valve is moved between said closed position and said open position in response to movement of said plunger;
- (f) a substantially cylindrical second housing portion having means defining an inlet at a first end thereof, said second housing portion defining an interior chamber of preselected variable volumetric size for containing a quantity of lubricating oil;
- (g) a piston slideably disposed within said second housing portion and including a surface thereof further defining said interior chamber;
- (h) spring means interposed between said piston and the second end of said second housing portion and biasing said piston toward a first axial position near said first end of said second housing portion;
- (i) electrical means for operatively interconnecting said solenoid and the ignition switch of said engine for selectively energizing said solenoid in response to operation of said ignition switch; and
- (j) a control circuit operatively interconnecting said solenoid and said electrical means and including a normally open time delay switching means and a normally closed electrical relay for selectively delaying the energizing of said solenoid in response to switchoff of said ignition switch upon shutdown of said engine.
- 8. The system as recited in claim 7 wherein said time delay switching means includes a thermal delay switch.
RIGHTS OF THE INVENTION
The invention described herein may be manufactured and used by or for the Government of the United States for all governmental purposes without the payment of any royalty.
The present invention relates generally to lubrication systems for internal combustion engines, and more particularly to a novel system for injecting lubricating oil to moving parts of an internal combustion engine prior to engine startup or after engine shutdown.
A substantial amount (some authorities estimate 70-80%) of wear in internal combustion engines occurs during engine startup before the oil pump begins providing adequate lubrication to the moving parts of the engine. Wear at startup is particularly pronounced in engines having significant periods of idle time between periods of active use during which idle time the engine cools off and the oil substantially drains off engine parts. Power carts for runway use around aircraft are representative of engines which may experience substantial idle periods between periods of intense use.
The general problem of engine wear at startup has been recognized and confronted by workers in the prior art, and numerous lubricating systems for solving this problem have been proposed. Representative of prior art lubricating systems for supplying oil to moving parts of an internal combustion engine prior to startup, such as upon switchon of the ignition, are represented by those disclosed in or referenced by U.S. Pat. No. 1,926,801 to Christian describing a system for pumping oil to the bearings of an internal combustion engine using a generator driven as a motor to turn an oil pump to force oil to the bearings when the ignition switch is turned on, afterward the generator-motor being reversed to act as a generator, which system does not pre-oil the bearings before the engine is cranked; U.S. Pat. No. 2,178,756 to Joost describing a lubricating system for an internal combustion engine to ensure preoiling before starting an engine by mechanical means blocking actuation of a first switch prior to actuation of a second switch; U.S. Pat. No. 2,273,888 to Paulsen describing an oil priming system for directing lubricant to the bearings of an engine at startup including a solenoid driven oil supply; U.S. Pat. No. 2,755,787 to Butler et al describing a preliminary lubricating device for an engine using an accumulator to supply oil as the starting system is energized and before the engine starts; U.S. Pat. No. 2,867,203 to Easton et al describing a pre-oiling device for an engine; U.S. Pat. No. 2,889,821 to Maki describing a manually operated system for providing heated oil to an engine at startup; U.S. Pat. No. 3,425,404 to Lamkin describing a pre-oiling device for engines including a reservoir with a solenoid driven diaphragm; U.S. Pat. No. 3,556,070 to Holcomb describing a lubricating system for energizing a solenoid and spring to open and close a valve in the oil line between an oil accumulator and the engine lubricating system; U.S. Pat. No. 3,842,937 to Lippay et al describing a manually operated pre-oiling system for an engine; and U.S. Pat. No. 4,112,910 to Percy describing a prelubrication system for an engine including a spring loaded piston.
The prior art systems suffer certain shortcomings which may include failure to inject oil to the lubrication system before the engine is cranked, or to allow sufficient time for a measured surge of oil to pass into the engine. Further, in some engine systems, such as internal combustion engine turbocharges, lubrication after engine shutdown may be highly desirable as a heat soak situation may exist after shutdown for which some fluid injected into the turbocharger both for cooling and lubrication may be desirable.
The invention solves or substantially reduces in critical importance problems with prior art systems by providing a system for automatically supplying oil to the bearings and moving parts of an engine just prior to engine startup in one embodiment, and just following engine shutdown in another embodiment. The system may be operatively connected to a lubrication pressure port of the engine and includes a solenoid controlled piston and cylinder arrangement which is filled with oil under pressure during normal engine operation and a control circuit for time delayed release of the oil from the cylinder just prior to engine startup or after engine shutdown. For prestart lubrication, pressurized oil in the cylinder is injected into the engine by a signal from the ignitions witch before the starter is engaged. For post shutdown lubrication, pressurized oil is released into the engine by preselected time delayed operation of the invention following shutoff of the ignition.
It is therefore a principal object of the invention to provide an improved lubricating system for an internal combustion engine.
It is another object of the invention to provide a lubricating system for an internal combustion engine wherein lubricating oil is automatically supplied to bearings and other moving parts inside the engine just prior to engine startup.
It is yet a further object of the invention to provide a lubricating system for an internal combustion engine wherein oil is supplied to the engine for a determinant time after engine shutdown.
These and other objects of the invention will become apparent as the detailed description of representative embodiments proceeds.
In accordance with the foregoing principles and objects of the invention, a system for automatically injecting lubricating oil into the lubricating system of an engine prior to startup of the engine or following shutdown of the engine is described which comprises a solenoid controlled spring-loaded piston and cylinder arrangement which is filled with oil under pressure during normal engine operation and a control circuit responsive to the ignition switch of the engine for controlled or metered release of oil from the cylinder either just prior to engine startup or after engine shutdown.
US Referenced Citations (16)
Patent Grant
4825826
