US 4,102,316 A · Hydromechanical shutoff for an internal combustion engine

Abstract

An engine shutoff device includes provisions to shut down an internal combustion engine under conditions outside the normal operating limits of the engine. While the engine is idling, shutdown is initiated by fuel cutoff when engine oil pressure is below a predetermined level. As engine speed increases the low oil pressure cutoff provided in the idle range is isolated from the system so that shutdown again by fuel cutoff will occur if oil pressure drops below a second predetermined level relatively greater than first predetermined level. Engine shutdown is also initiated by fuel cutoff when either coolant temperature or lubricant temperature is excessive. The engine can be manually shut down by an emergency valve that causes cutoff of the fuel and air supply. Finally, the device initiates engine shutdown by both fuel and air cutoff when an overspeed condition occurs. The device is comprised of a self-contained fluid pump, a speed-responsive valve spool, and a series of pilot operated valves which, with appropriate passages, form a series of fluid circuits. Engine lubricating oil is pressurized by the self-contained fluid pump and is passed through the series of circuits. Appropriate pressure and temperature sensing devices along with a speed sensing device are operable upon variation of pressure, temperature, or speed in the various circuits to actuate fuel shutoff or air shutoff as required.

Claims27

Dependent claims

In an internal combustion engine having fuel shutoff means and air shutoff means each operable for respectively blocking fuel and air supply to the engine, the engine further having a pressurized lubrication system and a liquid coolant system;

an engine shutoff device comprising:
a housing;
an unpressurized source of fluid;
engine driven fluid pump means mounted in said housing for pressurizing said fluid;
the housing defining first circuit passage means for communicating pressurized fluid from the engine driven pump means to the source;
first valve means interposed in said first circuit passage means and operably responsive to engine oil pressure for allowing communication of pressurized fluid from said engine driven pump means to said source while said engine oil pressure is greater than a first predetermined pressure;
second valve means also interposed in said first circuit passage means in a parallel arrangement with said first valve means and operably responsive to engine oil pressure for allowing communication of pressurized fluid from said engine driven pump to said source while said engine pressure is greater than a second predetermined pressure, the second predetermined pressure being greater than said first predetermined pressure;
and,
fuel lock means responsive to pressure in said first circuit passage means for operating the fuel shutoff means to block fuel to said engine.

6 more elements

An engine shutoff device for an internal combustion engine having fuel shutoff means and air shutoff means each actuable for respectively blocking fuel and air supply to the engine, the engine also having a pressurized lubrication system and a liquid coolant system;

the engine shutoff device comprising:
a housing:
a source of fluid;
pump means drivingly associated with the vehicle engine for pressurizing said fluid;
conduit means for communicating engine lubricant pressure to the engine shutoff device;
first and second passage means for communicating pressurized fluid from said pump means to said source;
fuel lock means responsive to increased pressure in said first passage means for actuating the fuel shutoff means;
air lock means responsive to increased pressure in said second passage means for actuating the air shutoff means;
first sense valve means interposed in said first passage means for blocking fluid communication in said first passage means while said engine lubricant pressure is below a first predetermined level and the engine is operating below a first predetermined engine speed;
second sense valve means interposed in said first passage means for blocking fluid communication in said first passage means while said engine lubricant pressure is below a second predetermined level above said first predetermined level and said engine is operating above said first predetermined engine speed;
interface valve means interposed in said first passage means and responsive to increased pressure in said second passage means for blocking communication of fluid pressure in said first passage means;
speed sense means interposed in said second passage means and responsive to engine speed for blocking communication in said second passage means above a second predetermined engine speed.

9 more elements

An engine shutoff device for an internal combustion engine having fuel shutoff means and air shutoff means each operable for respectively blocking fuel and air supply to the engine, the engine further having a pressurized lubrication system;

the engine shutoff device comprising:
a housing;
an unpressurized source of fluid;
fluid pump means mounted in said housing and drivingly connected with said internal combustion engine for pressurizing said fluid;
the housing defining first circuit passage means for communicating pressurized fluid from said pump means to the source;
first valve means interposed in said first circuit passage means and operably responsive to engine oil pressure for allowing communication of pressurized fluid from said pump means to said source while said engine oil pressure is greater than a first predetermined pressure;
second valve means also interposed in said first circuit passage means in a parallel arrangement with said first valve means and operably responsive to engine oil pressure for allowing communication of pressurized fluid from said pump means to said source while said engine pressure is greater than a second predetermined pressure, the second predetermined pressure being greater than said first predetermined pressure;
and
fuel lock means responsive to pressure in said first circuit passage means for operating the fuel shutoff means to block fuel to said engine.

6 more elements

Dependencies are inferred from the claim text.

Hydromechanical shutoff for an internal combustion engine

Life of this patent

Hydromechanical shutoff for an internal combustion engine

Life of this patent

Abstract

Claims27