US2336068A - Liquid cooling system for internal combustion engines - Google Patents

Description

11943. H. N. CHARLES 36,

LIQUID COOLING SYSTEM FOR INTERNAL COMBUSTION ENGINES Filed April 9, 1943 my flUbQrTMQ/ Char/e5 Patented Dec. 7, 1943 PATENT OFFICE LIQUID COOLING SYSTEM FOR INTERNAL COMBUSTION ENGINES Hubert Noel Charles, Birmingham, England, as-

signor to The Austin Motor Birmingham, England Application April 9, 1943, Serial No. 482,456 In Great Britain April 13, 1942 5 Claims.

The invention relates to liquid cooling systems for internal combustion engines.

Experience has shown that, with liquid cooling systems for vehicle engines and the like, substantial advantages accrue by providing two cooling circuits a small or primary circuit and a larger or main cooling circiut the flow to which is controlled by a thermostatically controlled valve which does not open until a predetermined temperature of the liquid has been reached.

The main circuit flows from the top of the engine jacket to the top of the radiator is usually adequately vented; and, in such passage, is placed the thermostatically controlled valve, the latter being closed when the liquid is below a given temperature. The primary circuit usually comprises a down pipe leading from the engine side of the thermostatic valve to the bottom of the radiator, usually joining into the usual return pipe from the radiator to the engine.

With the above arrangement a serious diffi culty has been encountered in filling and emptying the cooling system. To overcome this difliculty a permanent vent has been formed through the thermostatic valve which, when the radiator is being filled and the liquid is rising in the engine jacket, allows air to escape from the top of the jacket, through the vent in the valve and so to the top of the radiator.

The provision of a permanent vent in the thermostatic valve has, however, the same efiect as there would be if the valve never closed. As a consequence, when the liquid commences to circulate, a proportion of it can flow to the radiator and be cooled thereby instead of flowing solely by way of the primary circuit constituted by the down pipe. As a result the heating of the liquid is delayed; and, in very cold weather, the requisite temperature for the proper running of the engine may never be attained. The present invention has for its object to provide a system which is not subject to the above disadvantage, adequate venting being obtained without forming a vent through the thermostatic valve.

According to this invention there is provided a main down pipe which communicates, at its foot, with the bottom of the radiator or with the usual return pipe leading from the bottom or" the radiator to the bottom of the engine jacket or with a chamber communicating with the bottom of the radiator and with the said return pipe.

The main down pipe is closed at its upper end Company, Limited,

except for a suitable vent leading to the top of the radiator or to a point thereabove.

An auxiliary downpipe is taken off from a point on the engine side of the thermo-statically controlled valve and is entered, at its highest point, into the main down pipe, but not necessarily into the top of the main down pipe. At the point where the auxiliary pipe enters the main down pipe it is provided with a vent communicating with such down pipe.

As a result of the above, when the radiato is being filled and the liquid rising in the jacket, with the thermostatically controlled valve closed, the air from the top of the jacket can pass by way of the auxiliary pipe and the vent therein to the top of the main down pipe and from thence is vented to the top of the radiator or directly to the atmosphere. Hence the usual vent in the valve is rendered unnecessary.

The auxiliary pipe is preferably led down within the main down pipe to the bottom thereof, and enters into the said return pipe or the said chamber. It is open at its lower end and. such end may be presented towards the mouth of the return pipe.

When an engine, to which the invention is applied, has been started up, the valve is, of course, shut and the liquid rising in the engine jacket can flow through the auxiliary pipe to the said return pipe or to the said chamber and so back to the bottom of the engine jacket. When a given temperature is reached the valve opens and the liquid can then flow by the usual top pipe directly to the top of the radiator and circulate in the usual way.

Preferably, when the valve has opened to a predetermined degree, the entrance to the auxiliary pipe is closed. This may be effected by the usual sleeve depending from the valve and arranged so that it can cover such entrance.

The passage between the said chamber (if such is provided) and the bottom of the radiator is preferably partially closed, by a downwardly extending sill.

As the capacity of the chamber is relatively large the flow of liquid in it is relatively slow so that the tendency to cause fall of free surface level in the main down pipe is reduced. Thus the risk of the pump (which is usually provided) drawing air from the down pipe is avoided.

The pump'is usually provided in the return pipe and the effect of the sill is that it tends to cause liquid (which may have passed the vent in the auxiliary pipe and passed down the main down pipe) to enter the return pipe and not to flow into the bottom of the radiator.

Any liquid which may pass through the vent inthe auxiliary pipe merely enters the main down pipe and is not lost.

The invention is described with reference to the accompanying drawing, in which:

Figure 1 is a side elevation, in diagrammatic form and partly in section, illustrating a layout of a cooling system according to a convenient form of the invention, the thermostatic valve being shown open, the liquid circulating through the radiator in the usual way; and,

Figure 2 is a sectional view of the thermo statically controlled valve and valve chamber to an enlarged scale, the valve in this case being shown closed.

In the drawing A is the engine jacket, B a valve casing communicating with the top of the engine jacket and having a seating b in which is adapted to seat a valve C the stem of which is connected, at its foot, to the top of 'a thermostatic control device D which is anchored at its lower end to a bracket b fixed in, or formed as-part of, the casing, B. Thebracket has apertures, 22 therein to allow of the flow of liquid therethrough. Secured to the top of the device D is a plate E having a depending flange c (see especially Figure 2) which is a good sliding fit in the casing B. Apertures e in the plate E allow of the flow of liquid therethrough. The topof the casing 3 above the valve is in communication, by a pipe F, with the top header 3 of: agradiator F. f is the bottom header of the radiator. Communicating with this latter is a chamber G; but, in the opening between, there is; placed a depending deflector or sill g. The otherorouter end of the chamber G is in communication with a liquid pump'I-I by way of a bottom return pipe hand the delivery side of the pump is in communication, by a short pipe h, with the bottom of the engine jacket.

J is-the main down pipe communicating at its foot, with the top of the chamber G and being closed at its top except for a small vent pipe 7 leading to; the top header 7 of the radiator above thefree surface level which is indicated by the chain line at; :13.

From a position inthe wall of the casing D a short distance below the valve seat I) an auxiliary'pipe K isled off. This latter inclines upwardlyand at about its highest point enters the main downpipe'J; It extends downwardly therein and, at its foot, enters the chamber G to which it is open. The foot of the pipe K is bent somewhat towards the mouth of the return pipe h. Where the pipe K enters the pipe J it has a vent is: open to the interior of the pipe J.

When the engine is started up under cold conditions, the thermostatic control device D will be holding the valve C on its seat (as shown in Figure 2) and heated' liquid rising in the engine jacket, partly by therrno-syphon action, but chiefly by the action of the pumpH, will be entirely; prevented from flowing to the top header-fi as there is no vent through the valve; but, at such time, thefiange e will be below the entrance to the pipe K so that liquid can flow thereintoand from thence to thechamber G and to the pump H by which it is returned to the jacket. Any air that may collect in the top of the pipe K can escape by the-vents 7c and a? to the top: header 1; When the temperature of the liquid reaches a, predetermined degree, thevalve C will open and-cause the flange e to close the entrance to the pipe K. The flow of liquid will then be wholly through the radiator by way of the pipe F.

The cross-sectional area of the chamber 'G is considerably greater than the cross-sectional area below the sill g so that the rate of flow of liquid in the chamber G will be relatively slow. This ensures that the level in the pipe J will not fall appreciably as it otherwise might do under the action of the pump and allow air to pass into the chamber G and so to the pump and jacket.

In cold weather the liquid is usually drained ofi if a vehicle is to stand for a relatively long period; and the engine will usually be started up before the cooling system is refilled. The liquid is filled into the radiator in the usual way andwill rise in the engine jacket (and incidentally in the pipes J and K), and, the valve C being closed, the air in the jacket can escape by way of the pipe K and vent k to the pipe J from which it, can pass, by way of the vent pipe 7, to the top of the radiator. Any liquid which may pass through the vent is will enter the pipe J so that it will not be lost to the system.

Having fully described my invention what I claim and desire to secure by Letters Patent is:

1-. A cooling system for an internal combustion engine comprising a cooling jacket, a radiator, a top pipe leading from the top of said jacket to the toprof. said radiator, a bottom return passage leading from the bottom of radiator to the bottom of said jacket, a thermostatically controlled-valve adapted to cut on the flow of liquid through said top pipe, 2. main down pipe cornmunicating at' its foot with said return passage and being closed at its tep end except tor a vent.- passage, an auxiliary pipe ing, from a point between. said jacket and s thermostatically controlled.v valve, to. the said main down pipe, a vent hole in said auxiliary pipe near the top: thereofand communicating to the interior oi. the said main down pipe.

2.v A. cooling. system for an internal combusnon engine and comprising a cccling jacket, a

radiator, a. top pipe leading from the top of said jacket to. the. top. of said radiator, a bottom return passage leading from the bottom of said radiator to the bottom of said jacket, a thermostatically controlled valve adapted to cut off the flow ofliquid through said top pipe, a main down pipe communicating at its foot with said return passage and being closed at its top end except for a vent passage, an auxiliary pipe leading, from a point between said jacket and said thermostatically controlled valve, to the said mairrdown-pipe and passing down therein to a point near the foot thereof to which it is open,

and." a: vent hole in said auxiliary pipe near the top; thereof and communicating to the interior of" the said main downpipe.

3. A- cooling system for an internal combustion engine comprisinga cooling jacket, 21 radiator, a top pipe leading from the top of said jacket to the top'of said radiator, a bottom return passage leading from the bottom of said radiator to the bottom of said jacket, a thermostatically controlled valve adapted to cut ofi the flow of liquid through said top pipe, a main down pipe closed at its top end except for a vent passage, an auxiliary pipe leading, from a point between said jacket and said thermostatically controlled valve, to the said main'd'own pipe, a chamber of increased cross section in said return passag a. restricted. entrance to. saidmember from the bottom of said radiator, said main down pipe communicating at its foot with said chamber and. said auxiliary pipe passing down within said main down pipe to the interior of said chamber to which it is open, and a vent hole in said auxiliary pipe near the top thereof and communicating with the interior of said main down pipe.

4. A cooling system for an internal combustion engine comprising a cooling jacket, a radiator, a top pipe leading from the top of said jacket to the top of said radiator, a bottom return passage leading from the bottom of said radiator to the bottom of said jacket, a thermostatically controlled valve adapted to cut oiT the flow of liquid through said top pipe, a main down pipe closed at its top end except for a vent passage, an auxiliary pipe leading, from a point between said jacket and said thermostatically controlled valve, to the said main down pipe, a chamber of increased cross section in said return passage, a downwardly extending sill at the entrance to said chamber from the bottom of said radiator, said main down pipe communicating at its foot with said chamber and said auxiliary pipe passing down within said main down pipe to the interior of said chamber to which it is open, and a vent hole in said auxiliary pipe near the top thereof and communicating with the interior of said main down pipe.

5. A cooling system for an internal combustion engine comprising a cooling jacket, a radiator, a top pipe leading from the top of said jacket to the top of said radiator, a bottom return passage leading from the bottom of said radiator to the bottom of said jacket, a thermostatically controlled valve adapted to cut off the flow of liquid through said top pipe, a main down pipe communicating at its foot with said return passage and being closed at its top end except for a Vent passage, an auxiliary pipe leading, from a point between said jacket and said thermostatically controlled valve, to the said main down pipe and passing down therein to the said return passage to which it is open, and a vent hole in said auxiliary pipe near the top thereof and communicating to the interior of the said main down pipe.

HUBERT NOEL CHARLES.

Images