US2011876A - Engine cooling system - Google Patents

Description

1935- P. SAUNDERS 2,011,876

ENGINE COOLING SYSTEM Filed Feb. 26, 1934 Patented Aug. 20, 1 935 UNITED W 'E$1 z,011,s7t

ATE-N'TffoFsiE ENGINE ooonnvo SYSTEM Laurence P. Saunders, Lockport NQ Y., assignor to General MotorsC'orporation, Detroit, Mich,

alcorporation of Delaware Application February 26, 1934, Serial No; 712,878 1 I I Liquid circulating systems for internalcombustion engines require frequent replenishment of cooling medium and the loss is due largely to thermal expansion of the liquid. loss occurs during ordinary operation, but more-so in a'sho-rt interval immediately iollowing the stopping of thehot engine after a hard run, when both the ing system. A further object is to provideacooling system which may be'operated successfully with about half the amount of liquid used in the conventional system, sothat the engine may be run at a higher and more efiicient temperature than is the ordinary water cooledjoh .For a better understanding of the invention, reference may be made to the accompanying drawing, wherein Figure 1 is a side elevation of a power plant for motor vehicles, and Figure 2 is a detail sectional view taken at the outlet of the engine cooling jacket.

Referring to the drawing, the numeral l indicates an internal combustion engine which when in operation drives through a belt 2, a radiator fan 3 and a water pump 4. The water jacket of the cylinder block is provided with an outlet fitting 5 and with an inlet fitting 6, which inlet fitting may be connected through a hose section l with the discharge end of the pump 4. The suction side of the pump 4 is connected through a hose 8 with an elbow fitting 9 near the bottom of the outlet header or tank ID of the radiator assembly.

For the purposes of the present invention it is proposed to use a cross flow radiator of conventional design in which spaced horizontal water tubes provide a heat dissipating core extending between and connecting vertically disposed inlet and outlet tanks on opposite sides of the core. Either the inlet or the outlet header, but preferably the latter, is-provided with a lateral extension or top tank I I, lying above the core and having in its top Wall a filler spout l2 by which water may be introduced into the system. Near the uppermost portion'of the top tank II is an over -flow opening or air vent which may beiin the form ofa pipe-'ortube" 93 that extends from a point interior'ly of the filler spout l2 and through :a wall for instance, lnearY-the bottom of the assembly. Adjacent the top of the inlet tank, which in the drawing is on the far side of the radiator assembly; there is'provided a fitting It for connectionthroughthe hose. 15 with the jacket outlet fit I ting 5.- I

In the normal operationof the system theengine driven water pump' l forces'w ater irom the bottom of the outlet tank in, through the engine jacket to the inlet tank, for return to the outlet l header through the cool-ing unit, where the heat taken up by the water in its passage through the block is dissipated to an air stream drawn through the radiator-by the engine driven fan 3. Since it is proposed to operate" the circulatory system with a body of liquid'having'a. volume of substantially' half systemcapacity, it will be apparent that under ordinary operating conditions the pump tends to maintain the bulk of the liquid in the cylinder block jacket and because of the small amount of water used,- the engine will runat a -roomparatively"lngh temperature with'the water at or near boiling. Water and steam leaving the system will be quickly cooled and condensed in the cross flow radiator by the time it reaches the outlet header for return to the jacket.

The cross flow type of radiator with the air vent overflow associated with the outlet header,

and is converted into liquid before reaching the. "vented side of the tank.

However, when the engine driven fan is no longer active, the extraction ofheat would not be fast enough to prevent'loss through the air vent, and in order to eliminate surging and gushing of the liquid and steam from the system as a result of after-boiling, it is here proposed to block the jacket outlet as soon as engine'operation is stopped. For this purpose there is shown in the drawing a plate valve I6 seating on the underside of the attachment face ofthe fitting 5 and being mounted through a stem IT on one ofthe'tank to a convenient point of discharge, as

Q the flexible Walls [8 of an expansible chamdiator assembly.

. convenient engine controlled source of pressure,

such as the engine driven oil pump 23, which forms a part of the conventionalpressure feed lubricating system for the engine. When the engine is being operated the pump 23 delivers oil under pressure through the conduit 22 and expands the chamber to the broken line position v illustrated in Figure 2, in-which the disc valve [6 is unseated to allow free circulation of the cooling medium as heretofore described;

So soon as'the engineisturned off andv the oil pump 23 ceases to operate, the pressure being relieved, the expansible chamber contracts to the" full line position shown in the drawing and closes the valve IE to block further flow through the outlet connection to the inlet of-the radiator.

Under these conditions any boiling and expansion due to steam formation tends to push the body of water in the reverse direction and out through the inlet fittingto the outlet header of the ra- Since, however, the system is only half full the body or liquid within the radiator assembly will not reach the level of theoverflow, even though all the water is expelled from thercylinder jacket and, furthermore, the

water in the radiator. separates the overflow vent from the steam filled jacket and serves as a trap againstescape of vapors and to condense any steam which leaves the jacket.

While the above description has been more or less specific, the invention is not limited necessarily to the exactdetails shown, and it ,will be understood that radiators otherthan' the cross flow type referred to may be used, and that the closure valve may depend for its automatic action on devices other than'the pressure pump of the engine lubricating system. 7

Iclaim: p 1,. The combination with a pressure lubricating system for an engine, including an engine driven oil pump, and a circulatory engine cooling system including a radiator havinginlet and return connections with the engine jacket and an engine driven pump for forcing cooling liquid through the return connection during engine operation, of a. valvenormallyclosingv the radiator inlet connection, pressure actuated means for opening the valve and a pressure line for delivering oil under pressure from the engine oil pump to said means to hold the valve open throughout the period of engine operation.

2. In a. liquid cooling system for'engines, a cooling core for the .flow of cooling medium th erethrough, an overflow device associated with the core, an'engine jacket connection to one end of. the core, a valved connection to the other end 'of the'core, said valved connection including a valve adapted to open in opposition to the flow ofcooling medium through the connection and irrespective of how pressures, and means to open fand:to close thevalve automatically with the starting and the stopping respectively of the engine whereby to allow free: flow of cooling medium through-the connection'throughout engine operating periodsand to stop flow throughout intervals between engineoperating periods.

3. The combination with an engine jacket and a radiator having inlet and outlet connections with the jacket, .of a normally closed valve controlling communication between the jacket and the radiator inlet, a'pressure responsive device operatively connected with and adapted to open the valve in response to pressure, an engine drivon pressure pump, and means afiording free and i open communication at all times between said pressure pumpfand pressure responsive device.

'4. In 'an'erig'ine cooling, circuit, a valve controling the engine jacket outlet, and automatic meansresponsivegto changes in the oil pressure .of the engine to open the valve simultaneously .with the starting of engine operation and to close the valve simultaneously with the stopping of engine operation.

I LAURENCE P..SAUNDERS.

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