FI66059B - ANORDING FOER FOERBAETTRANDE AV EN FOERBRAENNINGSMOTORS KALLSTART - Google Patents

Description

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DEVICE TO IMPROVE COLD & START-UP OF AN INTERNAL COMBUSTION ENGINE

The invention relates to a device for improving the cold start of an internal combustion engine.

Starting a car or similar vehicle or implement in cold seasons after several hours of downtime is 5 uncertain. Especially in severe frosts, it is often not possible to start a car that has been standing outside overnight due to the high rotational resistance of the engine and the reduced battery charge, which reduces the current to the starter motor. In this way, the conditions for starting vehicles, etc. with a diesel, petrol or similar engine 10 are reduced. In addition, starting the internal combustion engine cold consumes the engine and shortens its service life.

Several devices and systems are known for improving the cold and / or frost start of an internal combustion engine. 15 Finnish patent publication EI 15 636 discloses an apparatus in which hot engine cooling water is transferred from the actual cooling system to a thermally insulated tank while the car is at a standstill. The hot water is returned to the cooling system, causing the engine temperature to rise and the rotational resistance to decrease. The disadvantage of this equipment is e.g. the fact that the tank, with its required effective thermal insulation, is relatively large and thus unreasonably takes up other possible useful space. In addition, care must be taken to transfer the cooling water to the tank when parking the car and from the tank to the cooling system when starting off.

DE-OS 1 805 862 discloses a thermal accumulator system in which a heat-insulated tank is provided in connection with either the engine's oil lubrication or cooling water system. During the standstill, hot lubricating oil or cooling water, respectively, is stored in the tank, which, when started by means of a pump, is properly transferred to 2 65059 corresponding engine compartments. The tank can also be filled with a suitable heat storage medium through which the lubricating oil or cooling water, respectively, is recycled. In this case, when starting the engine, the oil / water is pumped through the heat accumulator, which heats up.

The disadvantage of the thermocouple systems presented above is e.g. the fact that it requires a separate relatively large and thermally insulated oil / water tank to be fitted to the engine cooling or lubricating oil system.

10 Such a tank must be located as close as possible to the engine in order to reduce heat loss, which is difficult for older engines due to lack of space. In addition, the thermocouple system requires additional components such as an auxiliary pump, valves and connection lines, which increase the cost.

German patent publication DE-PS 1 158 756 discloses a lubricating oil preheating device arranged in connection with the oil sump of an internal combustion engine. through the wall of the oil sump, a conductor coil is mounted inside it above the oil surface, through which the heating medium 20 is conducted. The conductor coil is connected via a copper cylinder or other thermally conductive member to the lower part of the oil sump to the actual oil layer, e.g. to a strainer, pump or lines located there.

The disadvantage of the lubricating oil preheating device 25 described above is e.g. the fact that the device takes up space from the oil sump and that it can only be installed on new engines. Harhdinkie-Ruka's penetrations in the walls of the oil sump bring with them! vistysongelmia. In addition, the heating medium must be obtained from an external source before starting the engine.

30 It should be noted that there is a lack of thermal insulation, which results in large heat leaks between the unit and the oil sump and that, ultimately, the preheating is applied to the entire amount of oil in the oil sump.

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German application DE-rOS 2 115 221 discloses a device for improving the cold start of an internal combustion engine, in which an electric resistor is installed either inside or outside the oil sump and by means of which the lubricating oil of the engine 5 in the oil sump is heated. The main disadvantage of this device is that energy is needed, especially in severe frosts, because no thermal insulation has been used and almost the entire amount of lubricating oil is to be heated or kept warm. Therefore, the electrical-10 resistor must be connected to a normal electrical network.

DE-OS 2 713 153 discloses a lubricating oil preheating device for an internal combustion engine, in which an electric resistance element is located in a strainer placed in the oil sump, through which the lubricating oil is sucked into the engine by means of a pump oil filter.

The disadvantages of this preheating device can be mentioned, as in DE-OS 2 115 221 above, that the heat is due to the electrical resistance to the total amount of oil in the oil sump. The surface temperature of a single resistor immersed in the lubricating oil in the oil sump cannot be raised very high due to the risk of the oil igniting. Efficient preheating of lubricating oil with this device is not possible.

In addition, the lubricating oil circulates at start-up through the oil pump and filter and transfers heat to these devices and cools before entering the engine oil passages.

The object of the invention is e.g. eliminating the above drawbacks and implementing a reliable, yet simple, device that significantly improves the starting of an internal combustion engine in cold even arctic conditions. This is achieved by the features of the invention which are essentially set out in the first claim.

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The advantages of the invention can be seen as follows. During start-up, which takes up to 10 to 15 seconds, the amount of oil needed to lubricate the engine is a relatively small fraction of the total amount of oil in the lubrication system. In this case, the amount of a couple of deciliters of warm lubricating oil contained in the oil filter heat accumulator according to the invention 5, which is pumped directly through the main oil channel into the engine oil channels, is crucial for successful start-up. Achieving a critical engine start speed with diesel-10 engines is also likely.

Equipping the oil filter according to the invention with at least one electrical resistor and thermal insulation as a heat accumulator is reliable, simple and inexpensive. The number of accessories in a normal pressure circulating lubrication system 15 is small; no valves, additional pumps or wiring required. The integral replacement part, made of electric heater and thermal insulation, is easy to attach around the oil filter of both new and old cars.

In order to ensure a reliable start, the oil filter belonging to the engine-20 ti can be replaced by a filter with a larger oil space, and this according to the invention is provided with one or more electrical resistors and thermal insulation. This operation may be necessary for large implements.

the amount of oil to be heated or kept warm in the oil filter heat accumulator is relatively small in volume. The required heating power and thus the electrical resistance are then also of a reasonable magnitude. The electric heater can be connected directly to the motor battery or the auxiliary battery and does not overload the battery. This way, the car or machine is not dependent on an external heating source.

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In the following, the invention will be explained in detail with the aid of the accompanying drawing, i.e. Figure 1, which shows a pressure lubrication system of an internal combustion engine and an associated oil filter, which according to the invention is formed as a heat accumulator.

As is well known, four-stroke engines now have pressure circulation lubrication in common use. This is usually arranged so that the bottom of the crankcase 1, the so-called oil base, acts as an oil tank from which oil is sucked through a strainer 3 into an oil-10 pump 4. The oil is then forced through an oil filter 5 into an oil passage 6 from where it is passed through various oil passages to lubricate moving engine parts such as crankshaft, camshaft and valve train. The lubrication system of a diesel engine is basically similar.

According to Fig. 1, two electrical resistors 7, 8 are mounted on the outer surface of the oil filter 5 in such a way that the thermal power generated in them is transferred as efficiently as possible to the filter 5 itself and thus to the oil 9 therein.

20 with metal rims or strips, a thermal insulator 10 is placed around the oil filter 5 and the electrical resistors 7, 8. The electrical resistor or resistors 7, 8 and the thermal insulator part 10 can be joined together to form a cohesive whole which can be easily and quickly installed around the time.

In the embodiment of the invention according to Figure 1, the magnitude of the first resistor 7 is determined so that the thermal power delivered by it is of the same order as the amount of thermal leakage of the thermal insulation 10. In this case, the thermal power delivered by the resistor is sufficient. 30 to maintain the temperature of the filter and the oil in it at a level at least 20-30 ° C above ambient temperature. The second resistor 8 is dimensioned so that the temperature of the oil 9 contained in the oil filter 5 can be raised to a certain temperature in the desired time. Resistors 7, 8 __ - Γ 6 05059 are of such a power that they can be connected to the power supply of the car or the implement ram, i.e. to the battery 17, without overloading the battery during heating.

The electric resistors 7, 8 or one of them are connected to the power supply 5 either directly via the switch 21 or via the thermostat 18, 18 '. The sensor element 19 of the thermostat is placed either inside or on the surface of the oil filter 5. The desired maximum temperature can be installed and the thermostat monitors that this is not exceeded. In addition, a timer 10 20 can be used, in which case, for example, heating can be started at the desired moment before starting the engine.

The device according to Figure 1 operates as follows. When the car is left to stand on the street side on a cold winter evening for the night, switch 21 connects the first resistor 7 to the battery and in timer 20 sets the second resistor 8 to connect to the battery, e.g. 3-4 hours before starting in the morning.

In this case, the temperature of the oil in the oil filter remains almost constant by means of the first resistor for the morning hours, when the second resistor is switched on, the lubricating oil in the oil filter 5 now heats up to a certain temperature, e.g. 90 ° C, within a few hours. The thermostat 18, 18 'ensures that the desired temperature is not exceeded. When the engine is started after the standstill period, the lubricating oil is led directly from the oil filter 5 to the motor plain bearing and the rotational resistance of the engine-25 is considerably reduced. This ensures a reliable start-up.

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In cold-start tests using a device according to the invention, it has been found that the figure Kr {= starting current x battery voltage / motor-

30 speed) drop by 10 ... 30% compared to a conventional cold start.

6 5 0 5 9 The connecting pipes 13, 14 between the oil filter 5 and the rest of the engine lubrication circuit are preferably thermally insulated. the oil filter 5 and the connecting pipes 13, 14 can also be thermally insulated from each other in order to prevent unnecessary heat leaks towards the engine and its lubricant-5 lupir.

In the case of large engines and heavy machines, an oil filter with a capacity of, for example, 2 times its capacity, which is equipped with thermal insulation, can be installed instead of a conventional oil filter. This change ensures the sufficiency of the hot lubricating oil and thus the success of the cold start.

The invention has been described above mainly with reference to one of its preferred embodiments, but it is clear that the invention can be modified in many different ways without departing from the basic inventive idea, which is apparent from the appended claims. For example, only one electrical resistor, suitably controlled by a thermostat and / or a timer, can be used to heat or keep the oil filter warm. The electric resistor or resistors can also be formed as a heating element which is placed inside the oil filter.

Claims (6)

Device for improving the cold start of an internal combustion engine, characterized in that the oil filter (5) known per se has one or more electrical resistors (7, 8) and a thermal insulator (10) or the like, Device according to Claim 1, characterized in that an electrical resistor (7, 8) is arranged on the outer surface of the oil filter (5). Device according to Claim 1 or 2, characterized in that the electrical resistor (7, 8) and the thermal insulator (10) 10 can be connected together and thus form a unit which is interchangeable. Device according to one of the preceding claims, characterized in that a conventional oil filter (5) is replaced by an oil filter with a volume of 15, e.g. 2 times, relative to this, which is provided with thermal insulation. Device according to one of the preceding claims, characterized in that at least one electrical resistor (7, 8) is connected to the battery (17). 1 Device according to one of the preceding claims, characterized in that the electrical resistor (7, 8) is connected to the battery (17) via a thermostat (18) and / or a timer (20).