THERMAL DEVICE FOR INTERNAL COMBUSTION ENGINES

Abstract: A heating device to maintain the cooling system liquid or engine oil of a motor vehicle at a temperature above freezing to facilitate starting of the vehicle. The device may take the form of a tubular heating element (17) fitted into the lower radiator hose (14, 14a) between the radiator (12) and the engine. The device may also be incorporated in the construction of a radiator cap, a removable welch plug (1), the engine oil dipstick, the engine sump plug or comprise a heating element located in the lower part of the engine sump (30).

Description: THERMAL DEVICE FOR INTERNAL COMBUSTION ENGINES This invention relates to motor vehicles. Overnight in cold climates, the ambient temperature may fall to such a level that the liquid coolant in the engine cooling system may freeze: even if this does not occur, the viscosity of the oil in the engine lubrication system rises and makes the engine difficult to turn over whereby a severe strain is imposed on the battery and starter motor. To a certain extent, these problems may be mitigated, for example, by the use of anti-freeze compounds in the cooling system, and the use of multiviscosity oil of special formulation- in the engine lubrication system. These materials are expensive (in the case of the anti- freeze) or more expensive than the standard (in the case of the engine oils) . Furthermore, they do not affect the further problem that cold petrol-fuelled spark-ignition engines are difficult to start because of condensation of the petrol in the carburettor and inlet manifold. This problem is usually mitigated by the use of a manual or thermostatically controlled choke which causes a petrol rich combustible mixture to be inducted into the cylinders. Again, this approach has disadvantages in that fuel consump¬ tion is increased by use of the choke; the petrol-rich com- bQstible mixture inhibits efficient lubrication of the cyl¬ inder walls and causes premature wear; and last, but in the present political climate, by no means least, the use of the choke results in greater quantities of exhaust pollutants being produced. Consequently, it would be desirable if when a vehicle is garaged overnight, the engine could be maintained at an even temperature, sufficiently high to totally avoid the above problems, e.g. of the order of up to 65°C. However, in the broadest aspect, it is only necessary to prevent freezing of the engine coolant, in a liquid cooled engine. In this way savings could be made on coolant system anti-freeze, battery and engine wear, fuel, and oil. Additionally, the engine would start readily, and the vehicle could be immediately driven without any faltering, hesitation or stalling as some times happens with cold engines operating on choke. Broadly, the invention provides a heating device adapted to maintain the cooling system liquid or the lubri¬ cation system oil (and hence the engine) of a motor vehicle at a temperature such that the engine will readily fire without or with minimal choke operation. " In a preferred aspect, this invention provides a heat¬ ing device adapted to maintain the cooling system liquid of a motor vehicle at a temperature in the range above freezing to 65 C, said device comprising a heating element incorpor¬ ated in the construction of an open ended tube adapted to be sealingly connected into the bottom radiator hose of the vehicle, said element being on the inside of said tube so as to contact the cooling liquid in use, and cable means adap¬ ted to be connected to a source of electrical power to operate said element. A better understanding of the invention may be gained b reference to the accompanying drawings in which: Figure 1 illustrates one form of the device of the invention; Figures 2-4 illustrate further forms thereof; and Figure 5 illustrates one aspect of the device of the invention in situ; Figure 6 illustrates a preferred form of the type of device exemplified in Figure 5; Figure 7 shows the form of Figure 5 in somewhat more detail; Figure 8 illustrates a further form of the invention in situ on an engine. Referring to Figure 1, a welch plug 1 fits into the engine block wall 5 of a vehicle engine. It should be noted that when an engine is being manuf ctured, the block is cast to form a cooling liquid jacket. This is done by using a Q; " i core material occupying the space which will subsequently be used for the cooling liquid, in use. After casting, the core material has to be removed, and this is done through a hole, or holes, that was plugged during casting. Such holes have to be sealed when the engine comes into use in order to retain liquid in the cooling system. This is done by using a metal plug known as a welch plug. Normally, the welch plugs are in the engine block only. Returning to the drawings, a water sealed heating ele- ment 2 protrudes into the "water" jacket and is controlled by thermostat switch 3 fed by power coming in through cable connecting member 4. Figures 2-4 illustrate different forms of a plug la, lc and various heating elements 2a, 2b, 2c. In Figure 5, the bottom radiator hose of an engine cooling system is split into two portions 6, and 6a. Portion 6 connects directly to the lower portion of the radiator 7. A pair of clamps 8 fix the heating device 9 into the hose circuit by means of clamping to tubular portion 9a thereof. Heating element 10 extends into the tubular portion 9a and as before is thermostatically controlled. Power is dupplied via cord 11. In each of the above devices the heating element could be supplied power from the electricity mains by being plug¬ ged directly to a power point; alternatively, if the vehicle had sufficient battery power, the heating element could be operated therefrom. Referring now to Figures 6 and 7, a heating device is shown generally as 17, fitted into the lower radiator hose between radiator and engine. Radiator 12 has outlet 13 con- nected by length of hose 14 and clips 15 to device 17. At the other end thereof engine access opening 16 connects to device 17 by hose 14a and clips 15a. An all weather lock- able box 18 (mounted on the vehicle) encloses plug 18a lead¬ ing to cable 19 and heating element connection 21 of device 17. A thermostat device 20 is included in the cable 19. An extension cord and plug 25 from the mains supply can be .,::-o . connected to plug 18a to supply power to heating device 17. The latter comprises an inner metal tube 23 (preferably aluminium) , an element 22 coiled therearound, and an enclos¬ ing housing 24, also preferably of aluminium. Note that in the embodiment of Figures 5,6 and 7, the heated water rises into the engine to warm it rather than into the radiator, where much of the heat input could be lost by the cooling effect of the radiator. Figure 8 shows an embodiment wherein the heating elem- ent heats the oil in the sump of an engine. The sump 26 hav ing sump plug 26a is heated by element 30 therein, located below the normal oil surface level. Power is supplied via box 27 (which is like box 18 of Figure 7) cable 28, thermo¬ stat device 29 and connector unit 28a. This embodiment has special efficacy on air cooled engines, although it can be used with excellent results on liquid cooled engines also. Many benefits accrue from this heater. Thus the combus tion engine allows approximately 60% of fuel to pass through the combustion chamber until the engine cooling system reac- hes approximately 50 C. In extremely cold regions, starting from below zero, a standard design combustion engine may hav to run for about 30 to 120 minutes before reaching reasonabl economy. Tests have shown a drastic reduction in this waste after the engine reaches 50 C. The expulsion of carbon mon- oxide from the engine is at its lowest reading at about 80 C and remains substantially the same above this temperature level. Again benefits result because of the engine starting in a warm condition i.e. as this heater can maintain a control- led heat of approximately 60 C; as mentioned, a raw fuel passing through the combustion chamber and removing lubri¬ cant from the walls of the piston, increase engine cold start wear. Having the engine warm has the engine oil at a velocity that will lubricate efficiently and avoid the cold start wear. Also the electric start system will have a prolonged life. Further in the combustion engine motor car, the pre¬ heated engine will maximise driving safety when being driven into road traffic by eliminating stalling and lack of pick¬ up power. Fuel saving of a car being used five days per week in morning temperatures of zero and below for journeys of twenty-five kilometres, are as high as 40% based on a car that starts at 60 C compared to the car starting from zero temperature or below. The warm engine crankshaft revolves and starts with one fraction of the power required to rotate the crankshaft of an engine in zero temperature or below conditions, and this gives an extended life of between 30 to 40 percent to the life of the starter motor and battery. In Figure 8 this heater is set at 65 C and is primar¬ ily designed for the air cooled engine. The heat generator upwards from the sump oil penetrates through the pistons in¬ to the firing chamber preparing the engine for dependable starting and reduces fuel loss, and allows maximum lubrica- tion. This heater can also be used in any combustion engine, as previously stated. For safety reasons and also to maximise reliability, the preferred units of Figures 6,7 and 8 will be manufactur¬ ed complete, that is, the element, cable, thermostat control and the all weather plug, shall be all moulded together and installed as such, reducing power leakage from garage work¬ shop fitted connections. While the foregoing description relates mainly to spark ignition engines, the device is applicable to diesel engines also; apart from the embodiment of Figure 8, the invention is applicable also to air cooled engines in that the heating element could be inserted in the sump plug aperture or associated with the dip stick whereby to heat the oil coll¬ ected in the sump. If the oil in the sump is being heated, a special sump plug with heating element is constructed and left screwed into the sump - power is supplied thereto by a removable cable. It is to be noted that the radiator cap of the vehicle cooling system may be constructed to include a heating element as the device of the invention. It should be remarked that for the sake of brevity whilst the foregoing disclosure relates to maintaining the engine of a vehicle at such a temperature as to facilitate starting and/or to achieve other advantages, it is intended that the invention also embraces bringing an engine to a suitable temperature in a relatively short time, and also in the broadest aspect, to merely prevent freezing of liquid cooled engines. Finally, it is to be noted that the present invention is not to be restricted to the specific embodiments parti¬ cularly described but embraces mechanical and electrical equivalents such as are known to those skilled in the relevant arts.

Claims: CLAIMS : 1. A heating device adapted to maintain the cooling system liquid or the engine oil of a motor vehicle engine at a tem¬ perature in the range above freezing and up to a temperature such that the engine is readily startable without or with minimal choke operation. 2. A heating device adapted to maintain the cooling system liquid of a motor vehicle engine at a temperature in the ran¬ ge above freezing to 65°C, said device comprising a heating element incorporated in the construction of an open ended tube adapted to be sealingly connected into the bottom rad¬ iator hose of the vehicle, said element being on the inside of said tube so as to contact the cooling liquid in use, and cable means adapted to be connected to a source of electri¬ cal power to operate said element. 3. A heating device as in Claim 1, said device adapted to incorporate into the cooling system of a liquid cooled eng¬ ine, and comprising an open ended tube section adapted to be sleeved into the lower radiator hose, a heating element coi¬ led around the outside of said tube section in contact there¬ with, and a housing enclosing said element and that portion of the tube section associated therewith, a power cable con¬ nected to said element, a portion of said tube section at each of its ends being free of said housing and element, whereby said portion can, in use be sleeved into respective portions of said lower hose, and sealingly affixed thereto by clamp means. 4. A heating device as in Claim 1, said device adapted to heat the engine oil, and comprising a heating element incor¬ porated in the construction of the oil dipstick or sump plug, said element in contact with the oil when said dipstick or said plug is in position, and cable means adapted to be con¬ nected to a source of electrical power to operate said elem¬ ent. 5. A heating device as in Claim 1, said device adapted to heat the cooling system liquid, and comprising a heating element incorporated in the construction of a removable welch plug or of the radiator cap, whereby in use said heating element is on contact with said liquid, and cable means adapted to be connected to a source of electrical power to operate said element. 6. A heating device as in Claim 1, said device adapted to heat the engine oil, and comprising a heating element adap¬ ted to be located in the engine oil sump below the normal level of the oil surface, a connector unit uniting said element and a power cable, said connector unit being adapt¬ ed to be mounted sealing on the wall of the sump to position said element inside thereof and with said cable external thereto. 7. A heating device as in Claim 6, wherein said cable terminates in a plug located in an enclosed housing mounted on the vehicle, said housing including a lockable panel for access to said plug, and said cable including a line thermo¬ stat control. 8. A motor vehicle engine in combustion with a heating device as claimed in any one of Claims 2 to 7. 9. ' A heating device substantially as hereinbefore describ¬ ed with respect to the accompanying drawings. 10. The combination of Claim 8 substantially as hereinbef¬ ore described with respect to the accompanying drawings.

Inventors: SHAND A
Applicants: SHAND A
Application year: 1980
Main classification: F01M5
IPC codes: F01M5, F01P11