US1920805A - Heating system for internal combustion engines - Google Patents

Description

, Aug. 1, 1933. Q p RANDOLPH 1,920.805

HEATING SYSTEM FOR INTERNAL COMBUSTION ENGINES Filed March 15, 1932 Inventor: ChQTlGS F Randolph,

by His Attorney.

Patented Aug. 1, 1933 HEATING SYSTEM FOR INTERNAL COMBUSTION ENGINES CharlesP. Randolph, Oak Park, llll., assignor to Edison General Electric Appliance Company, Chicago, Ill, a Corporation of New York Application March 15, 1932. Serial No. 598,926

8 Claims. (61. 123-496) My invention relates to-heating systems for internal combustionengines, such as are commonly used to propel automotive vehicles and the like, and has forits object the provision of an improved heatingjsystem of this character.

More specifically, my invention contemplates the provision of an improved heating system whereby the engines fuel and lubricating medium are heated so as to facilitate the starting of the engine and to insure its lubrication.

It is well known that oftentimes it is dimcult to start an internal combustion engine when the fuel is improperly or insufficiently vaporized.

In cold weather, in particular when the intake manifold of the engine, which member is generally utilized to assist in the vaporization of the fuel that is to be distributed to the engine cylinders, and the metallic parts adjacent it are cold, considerable effort and skill on the part of the operator are required to start the engine and keep it running. And it is only by choking the carburetor considerably that he is likely to succeed in starting at all. This practice of choking results in considerable Waste of fuel and deterioration of the lubricating medium.

As is well known, when the oil is in a stiifor overly viscous condition, the engine, if it can be started, will not pump suficient oil to the bearings to insure perfect lubrication of these members with the result that some parts of the en- 7 gine likely will be damaged.

' It is an object of my invention to provide an improved engine heating system that will overcome these difiiculties. V

In carrying my invention into effect in one form thereof, I provide means for heating fuel to vaporize it before it is supplied to the engine cylinders, and in addition provide means for heating the lubricating oil in the engine crank 03158. To prevent overheating, i. e., to cut down the heat supplied by the heating means whenthe engine itself becomes sufficiently heated to vaporize the fuel-and to keep the oil sufficiently mobile to flow readily to the bearings, the heati= ing means'will be controlled in accordance with r the temperature of a member which generally is heated considerably when the engine is running.

For this purpose, a control device arranged to cut the Eheating means on and off responsively to the temperature of the intake manifold may be used and in the embodiment of my invention herein-illustrated will be used.

For a more complete understanding of my invention, reference should be had to the accom- 5 I panying drawing in which the single figure is a diagrammatical representation of an automotive 7 vehicle internal combustion engine provided with heating means arranged in accordance with my invention.

Referring to the drawing, I have shown my invention in one form as applied to an autoinotive vehicle power plant of the internal combustion type. This engine is of the multiple cylinder type and, as shown, comprises a head casting 10 which includes a plurality of cylinders (not shown), and a crank case 11 in which the engine crank shaft (not shown) is arranged to rotate in suitable bearings provided for it. The engine is provided with an intake manifold 12, to which fuel is carried to the engine cylinders. Fuel is supplied to the intake manifold 12 by a carburetor 13. The carburetor 13 is provided with a float chamber 14 and with an air intake passageway 15. Within the crank case 11 an oil pump 16 of any suitable type is arranged to force oil from the oil sump 17 to the lubrication system of the engine. 7

During the normal'operation of the engine, fuel in a more or less vaporized condition is supplied by the carburetor 13 to the'manifold 12 where his further vaporized by the heat imparted to it from the walls of the manifold; by the time the fuel reaches theengine cylinders it is usually in a condition suitable for ignition and combustion. It will be understood that the intake man'ifold 12 will be'heated to some extent by the exhaust pipe (not shown) so that after the engine 7 has been running for some time usually no diffioulty will be experienced by reason of poor vaporization of fuel. 9

However, when the engine has been standing idle in the cold for some period of time, the exhaust pipe is cold and so'are the intake mani- "fold and the metallic parts adjacent it. As a result, the intake manifold affords no assistance to the carburetor in vaporizing the fuel. It is because of this that it is necessary to choke the carburetor considerably in starting the engine in cold weather.

To overcome this difiiculty, I provide the carburetor with a fuel vaporizing chamber 21 constituting an auxiliary fuel vaporizer. As shown in the drawing, this chamber is associated with the air intake passageway 15 so that its discharge outlet or mouth 22 leads directly into the passageway.- Preferably and as shown, the chamber 21 will be formed integrally with the intake passageway and will be arranged to depend from it. The vaporizing chamber 21 is supplied with-fuel from the carburetor float chamber 14, these chambers being in direct communication by means of a passageway 23. It will be understood that the float chamber will maintain a suitable fuel level in the auxiliary chamber 21.

In order to vaporize the fuel which is supplied to the chamber 21, I provide the chamber with a suitable heating element 24. This heating element, as shown, projects upwardly into the chamber from its bottom wall..

The heating element 24 will have suflicient ca-' pacity to quickly vaporize the fuel supplied to the chamber 21. It will be understood, of course, that the chamber 21 will be supplied with fuel from the float chamber 14 to replenish-that vaporized by the heating element 24.

It will be observed that the fuel which is vaporized in the chamber 21 will pass directly into the air intake passageway 15 of the carburetor, and thence will be carried through the carburetor and discharged into the intake manifold 12 from where it will be directed to the engine cylinders.

The auxiliary vaporizer will have a capacity sufficient to provide the engine cylinders with an ample supply of vaporized fuel even though the intake manifoldbe cold. The fuel thus passed in vaporized condition to the engine cylinders is ready for ignition and combustion thereby permitting prompt starting of the engine. As has been pointed out in a previous portion of this specification, oftentimes when the engine has been standing idle in the cold for some period of time, the lubricating medium becomes so stiff that it does not flow freely through the lubricating system.

In order to render the oil mobile so that it will readily flow through the lubricating system, I provide an additional heating element 25 in the oil sump 1'7 adjacent the oil pump 16. This heating element will have a capacity such that when energized it will quickly heat up the oil in the crank case and render it mobile and fit for lubrication. 1

The heating elements 24 and 25 will be energized from any suitable source of electrical energy 26 which may be the usual battery found in automotive vehicles. As shown, the positive side of the battery may be connected with one side of each of the elements 24,25 through a control switch 27, whereas the negative side of the battery and the remaining terminal of each of the heating elements are grounded to the internal combustion engine.

The switch 2'7 may be any suitable manually operable switch, but preferably will bearranged so as to be operated with the ignition switch (not shown) of the automobile, whereby when -the operator turns the ignition on he will automatically and unconsciously energize the heating elements 24 and 25. 7

As pointed out above, the heating elements 24 and 25 are controlled so as to prevent overheat-- ing, or in other words, are cut off when they have performed their heating functions.

For this purpose, I have provided a suitable temperature responsive device 28, this device being arranged to respond directly to the temperature of the intake manifold 12. As shown, the temperature responsive device 28 comprises a bimetallic thermostatic element 30. The bimetallic element 30 controls a switch 31 which is included in the electrical connections between the battery 26 and the heating elements 24 and 25. When the bimetallic element 30 is cold; it will be in a position to maintain the switch 31 closed,

whereas when it is heated to a certain predetermined maximum temperature it will operate to open this switch and hence open the heating circuit.

While any suitable heating elements may be used for the heaters 24 and 25, I prefer to use those of the sheathed wire type, such as described and claimed in U. S. Patent No. 1,367,341, granted to C. C. Abbott and dated February 1, 1921. Briefly, this element comprises another metallic sheath enclosing a resistance heating conductor (not shown) embedded in a suitable compacted, heat-conducting, electrically-insulating material, such as magnesium oxide (not shown).

In the operation of my heating system, when the operator desires to start the engine, he will,

of course, turn on his ignition switch. At the same time the switch 2'? will be automatically closed by the operation of the ignition switch, or the switch 27 may be closed by a separate operation if desired. When the switch 27 is closed, an energizing circuit will be completed for the heating elements 24 and 25 which will immediately operate to vaporize the fuel which is supplied to the chamber 21 and to heat the oil in the oil sump 17. After a relatively short period of time has elapsed, vaporized fuel will be supplied to the intake manifold in such quantities that the operator may start the engine, by pressing on the starter.

During the preheating period the lubricating oil in the crank case will be rendered mobile so that when the engine is started a supply of oil in free running condition will be supplied to the lubrication system of the engine to insure perfect lubrication.

After the engine has been running for a period of time to allow the intake manifold to become sufficiently heated to thoroughly vaporize the fuel supplied to it, the thermostat 28 will operate to open the switch 31 in the energizing circuits for the elements. 24-and 25.

It will be understood that when the engine has been running for such a period of time that the intake manifold is heated sufficiently to effectively vaporize the fuel supplied to it, the engine will be heated sufliciently to keep the oil in the crank-case and lubrication system sufiiciently mobile. Hence, in effect, the temperature of the intake manifold becomes a measure of the viscous condition of the lubricating oil and may be utilized to cut off the heater 25 as well as the heater 24.

When the engine has been stopped, as by turning off the ignition, the intake manifold will cool off and the thermostat 28 will operate to close the switch 31 thereby rendering the heating system effective for a, subsequent starting.v

operation. The thermostat, of course, will be set to close only if the manifold cools to such an extent that it would improperly vaporize the .fuel if the engine were restarted.

While I have shown the thermostat 28 arranged to respond to the temperature of the intake manifold, it will be understood that it may respond to the temperature of any suitable portion of the engine that becomes heated by the running of the engine. Thus, for example, the thermostat may respond to the temperature of a cylinder wall.

While I have shown a particular embodiment of my invention, it will be understood, of course, that I do net wish to be limited thereto since many modifications may be made, and I, there- 7 engine, heating means arranged to heat the lubricating medium of said engine and means dependent upon the temperature of a portion of.

said engine normally heated by the operation thereof for controlling both of said heating means.

2. In an internal combustion engine, a source of fuel supply, a member for vaporizing fuel to be supplied to said engine, means for heating fuel to vaporize it and for delivering the fuel thus vaporized to said vaporizing member, a source of lubricating supply, means for heating said lubricating supply and means controlling both of said heating means in accordance with the temperature of said vaporizing member.

3. In combination with an internal combustion engine provided with an intake manifold, means for supplying said manifold with vaporized fuel, auxiliary means for supplying said manifold with vaporized fuel comprising a vaporizing chamber, means for supplying fuel to said vaporizing chamber, heating means arranged to heat said chamher so as to vaporize the fuel supplied to the chamber and means controlling said heating means in accordance with the temperature of said intake manifold.

4. In combination with an internal combustion engine provided with a crank case, a lubricating medium in said crank case, means for heating said lubricating medium and means controlling said heating means in accordance with the temperature of a portion of said engine normally heated by the operation thereof.

5. An internal combustion engine comprising an intake manifold, a carburetor for supplying fuel to said intake manifold, heating means ar ranged to heat and vaporize fuel and. supply it to the intake of said carburetor, heating means arranged to heat the lubricating medium of said engine and means for rendering said heating means inefiective when the temperature of said manifold has reached a predetermined high value.

6. In combination with an internal combustion engine provided with an intake manifold and a carburetor of an auxiliary vaporizing chamber associated with the air intake of said carburetor, means for supplying said chamber with fuel from said carburetor, a heating element in said vaporizing chamber and a temperature responsive device controlling said heating element in accordance with the temperature of said intake manifold.

"I. In combination with an internal combustion engine provided with an intake manifold and a carburetor of an auxiliary vaporizing chamber associated with the air intake of said carburetor, means for supplying said chamber with fuel from said carburetor, a heating element in said vaporizing chamber, a heating element in the crank case of said engine, a common energizing circuit for both of said heating elements, a switch controlling said circuit and a temperatureresponsive device controlling said switch in accordance with the temperature of said intake manifold.

8. In combination with an internal combustion engine provided with a crank case, a lubricating medium in said crank case, means for heating said lubricating medium and a thermostat respcnsive to the temperature of the intake inanifold of said engine controlling said heating means.

CHARLES P. RANDOLPH.

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