JPH0979020A - Lubricating oil heating device for internal combustion engine and lubricating oil moderate temperature holding method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To heat lubricating oil efficiently by an indirect heating system. SOLUTION: A circulating line 10 that can circulate heated radiator water is provided separately from a cooling circulating line 6 so as to be able to heat lubricating oil indirectly with heated radiator water through a water-cooled oil cooler 1 when the temperature of the lubricating oil in an internal combustion engine is low. This circulating line 10 is provided with a circulating pump 12 for circulating radiator water, and a heater 11. When the lubricating oil is the specified temperature or lower, heated radiator water is circulated to the water-cooled oil cooler 1 to heat the lubricating oil, and when the lubricating oil reaches the specified temperature, cooled radiator water is circulated to the water-cooled oil cooler 1 to cool the lubricating oil so as to be held to the moderate temperature.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a lubricating oil heating apparatus for an internal combustion engine.

[0002]

2. Description of the Related Art Lubricating oils for internal combustion engines such as automobile engines have a high viscosity at low temperatures and may be difficult to start in cold regions. On the other hand, if the lubricating oil has a suitable temperature,
It is possible to reduce mechanical loss, improve fuel efficiency (fuel consumption rate), and reduce harmful exhaust gas. For this reason, in order to maintain the temperature of the lubricating oil at an appropriate temperature at the time of starting or immediately after that, some internal combustion engines are provided with a heating means for the lubricating oil. As an example, there is known a technique of mounting a sheathed heater, which is made of metal such as aluminum, in an oil pan of an internal combustion engine, or a technique of directly mounting a heater in oil.

[0003]

In the former case, since the heater is cast in aluminum or the like, it is difficult to increase the heat generation density, and the heater itself must be made large in order to increase the heater capacity. However, increasing the size of the heater causes an increase in weight. On the other hand, if the heater capacity is small, it takes a long time to heat the lubricating oil. Further, there is a problem that the heat transfer efficiency is poor due to indirect heating.

On the other hand, the latter has a high heat transfer efficiency because it is a direct heating system, but when the heat generation density is increased, the surface temperature of the heater rises, and the lubricating oil in contact with it is carbonized.
Further, if this carbonization proceeds further, there is a problem that the efficiency of heat transfer to the lubricating oil is lowered, the temperature of the heater is raised as a result, and the life of the heater is shortened.

By the way, the heating of the lubricating oil is required at the time of starting the internal combustion engine, such as when the engine is cold, that is, when the lubricating oil temperature is low, and after the starting until the lubricating oil rises to an appropriate temperature. After the temperature rise, on the contrary, it is necessary to cool the lubricating oil so as not to exceed the limit temperature. Therefore, the conventional internal combustion engine is usually equipped with an oil cooler. Among them, those equipped with a water-cooled oil cooler (hereinafter, also referred to as an oil cooler or simply a cooler) circulates radiator water (engine cooling liquid) through the oil cooler to cool the lubricating oil. An object of the present invention is to provide a lubricating oil heating device and a method for keeping the lubricating oil at a proper temperature, focusing on these points and solving the problems of the above-mentioned conventional techniques.

[0006]

In order to achieve the above object, a lubricating oil heating apparatus for an internal combustion engine according to the present invention uses a liquid such as heated water, which is different from the lubricating oil of the internal combustion engine. To be indirectly heated via the heat transfer part,
A heating circulation pipe through which the liquid can circulate through the heat transfer unit; a circulation pump that circulates the liquid in the heating circulation pipe; and a heating unit that heats the liquid. It is characterized by The liquid here may be heated water or the like different from the lubricating oil, but it is appropriate to use radiator water.

In this case, the heat transfer section may be a water-cooled oil cooler provided for cooling the lubricating oil of the internal combustion engine. Further, the circulation pipeline is formed so as to pass through the inside of the cross section of the oil pan of the internal combustion engine or through the lubricating oil accumulated on the oil pan, and the heat transfer portion is inside the cross section of the oil pan or the oil. It may be a part of the circulation line that passes through the lubricating oil accumulated on the pan. In the above, it is preferable to use a ceramic heater as the heating means.

Further, the method for keeping the lubricating oil at an appropriate temperature according to the present invention is a water-cooled oil cooler provided for cooling the lubricating oil of the internal combustion engine, wherein the lubricating oil has a predetermined temperature or less. In the case of, the lubricating oil is heated by circulating the heated radiator water, and when the lubricating oil reaches a predetermined temperature, the lubricating oil is circulated by circulating the cooled radiator water. Is characterized by cooling.

[0009]

Embodiments of the present invention will be described below with reference to the drawings. In FIG. 1, reference numeral 1 is a water-cooled oil cooler attached to a gasoline engine for automobiles for cooling lubricating oil. The water-cooled oil cooler 1 is provided with a pipe 1a through which lubricating oil circulates, and radiator water (engine cooling liquid) cooled (radiated) by a radiator (not shown) in order to cool the lubricating oil.
So as to circulate through a pump (not shown), a feed pipe 4 and a return pipe 5 are connected to an inlet 2 and an outlet 3 of the pump, and a circulation pipe line 6 for cooling (cooling water) is provided. .

In the present example, electromagnetic three-way valves 7 and 8 are provided in the middle of the feed pipe 4 and the return pipe 5, respectively, and a pipe 9 is provided through the two three-way valves 7 and 8 as shown in the figure. Branched off,
Separately from the cooling circulation pipe 6, a heating circulation pipe 10 for heating the lubricating oil is provided. A heater 11 and a circulation pump 12 as heating means for radiator water introduced through the three-way valves 7 and 8 into the circulation pipeline 10 are provided in the middle of the circulation pipeline 10 for heating. Thus, the radiator water is substantially filled in both circulation pipe lines 6 and 10.

In this example, the temperature of the lubricating oil is detected, and when the temperature of the lubricating oil is lower than 70 ° C. by a temperature detector (not shown), heating is performed by circulating the heated radiator water in the water-cooled oil cooler 1. The two three-way valves 7 and 8 are each controlled to be opened and closed so that a circulation pipe line 10 for the vehicle is formed. On the other hand, when the temperature of the lubricating oil is detected by the same temperature detector and is 70 ° C or higher, the two three-way valves 7 and 8 are controlled to be opened / closed (switched), and the water-cooled oil cooler 1 is cooled by the radiator. A cooling circulation pipe line 6 for circulating the generated radiator water is formed.

In this example, the switching (opening / closing) of the three-way valves 7 and 8 is performed at 70 ° C., but this temperature may be set to a suitable temperature according to the type of lubricating oil. Further, if necessary, the circulation pipe 10 for heating may be provided with a safety device such as a relief valve so that the inside thereof does not have an abnormally high pressure.

In this example, when the temperature of the lubricating oil is detected to be less than 70 ° C. by the temperature detector, the heater 11 is energized to heat the radiator water and the circulation pump 12
Is set to be activated. As a result, the heated cooling water is pressure-fed (circulated) to the cooler 1 through the same circulation pipeline 10, and the circulating lubricating oil is heated via the heat exchange section as indicated by the broken line in the figure. . On the other hand, when the lubricating oil is heated and detected by the temperature detector to be 70 ° C. or higher, the energization to the heater 11 is stopped and the operation of the circulation pump 12 is also stopped.

The heater 11 is, as shown in FIG. 2, an aluminum case 1 provided in the middle of the circulation line 10.
3, an alumina ceramic heater 14 is provided, and the heater 14 is configured to directly heat the radiator water W which is circulated while being submerged in the radiator water W. However, in this example, the heater 11 is energized at the same time as or after the operation of the circulation pump 12 (after the circulation of the radiator water) in order to prevent damage to the heater 14 due to boiling of the radiator water W. Is set. Similarly, the operation of the circulation pump 12 is stopped when the heater 1
It is set to be performed at the same time as the stoppage of the energization to 1 or a predetermined time after the stoppage of the energization.

As described above, in the present embodiment, when the lubricating oil is detected to be lower than 70 ° C. at the time of starting the internal combustion engine, the circulation pipe line 10 for heating is connected as shown in FIG. The three-way valves 7 and 8 are controlled to open and close, the circulation pump 12 operates, and the heater 11 is energized. This allows
The radiator water in the circulation pipe 10 is heated and circulates in the circulation pipe 10 as indicated by an arrow in the figure, and heats the lubricating oil via the heat exchange section of the cooler 1.

When the heated lubricating oil reaches 70 ° C. or higher, the operation of the heater 11 and the circulation pump 12 is stopped. At the same time or after a predetermined time, as shown in FIG. 4, the three-way valves 7 and 8 are switched to communicate with the cooling circulation pipe line 6, and the water-cooled oil cooler 1 radiates heat (cools) with a radiator. The radiator water thus circulated circulates as shown by the arrow in the same figure as in the conventional case to cool the lubricating oil and maintain its temperature at an appropriate temperature.

In the present embodiment, the heated radiator water circulates in the heating circulation pipe line 10 and the cooler 1
Is used as a heat transfer portion to heat the lubricating oil. At this time, since the radiator water to be heated is only in the circulation pipe line 10, it is heated in a short time. As a result, the lubricating oil can be heated by the cooler 1 as the heat transfer portion in a short time and kept at an appropriate temperature. Therefore, even immediately after the engine is started, its performance and fuel efficiency can be improved. As is clear from this, in the present embodiment, it is preferable to design the circulation line 10 so that the capacity of the heated radiator water is small.

Further, in the above, since the heat transfer section is the water-cooled oil cooler, it is not necessary to provide a separate independent heat transfer section, and the water-cooled oil cooler has the function of the heat transfer efficiency to the lubricating oil. It has a structure with excellent (heat exchange performance). Therefore, when the water-cooled oil cooler is provided, it is preferable to use it as the heat transfer portion.

Further, as in the above-described embodiment, when the circulation pipe line 10 for heating is provided by branching from the circulation pipe line 6 for cooling the cooler 1, the water (liquid) for heating, and Since a tank or a reservoir for storing the water is not required, the structure can be simplified. In the above description, the cooling pipeline 6 for cooling the cooler 1 is branched to provide the circulating pipeline 10 for heating, so that the cooling pipeline is partially used also as a circulating pipeline. It is also possible to provide valves at the inlet 2 and the outlet 3 of the radiator water of the cooler 1, respectively, and to independently provide a circulation channel for heating to each of these valves without being combined.

In the above, since the alumina ceramic heater 14 directly heats the radiator water and heats the lubricating oil with this heating water, the heating efficiency of the lubricating oil is extremely high, and after the temperature rises, Since the lubricating oil can be cooled by circulating the cooled radiator water, the temperature of the lubricating oil can be efficiently maintained at an appropriate temperature. Further, since the radiator water is directly heated by the ceramic heater 14, even if the heat generation density of the ceramic heater 14 is increased, there is almost no carbonization as compared with the case of directly heating the lubricating oil. It does not cause an abnormal rise in. Therefore, the life of the heater 14 can be extended. However, the heating means used in the present invention is not limited to the ceramic heater made of alumina, silicon nitride, aluminum nitride or the like, and an appropriate heater such as a metal sheath heater can be used.

In FIGS. 5 and 6, a circulation pipe 30 provided with a heater 21 and a circulation pump 22 is provided so as to penetrate through a cross section of an oil pan (oil receiver) 31 of an internal combustion engine (engine). An embodiment of the invention is shown in which the transmission portion is a portion of a circulation pipeline 30a passing through the inside of the cross section of the oil pan 31. In this case as well, radiator water for cooling the cooler may be circulated, or a liquid (water containing antifreeze liquid or the like) other than this may be introduced into the circulation pipe line 30. Further, as shown by the chain double-dashed line in FIG. 6, the circulation pipeline 30b may be provided so as to pass through the lubricating oil J on the oil pan 31, and the portion of the circulation pipeline may be used as the heat transfer portion. Further, the circulation pipeline in the above-described embodiment may be provided so as to pass through the inside of the oil pan cross section or through the lubricating oil accumulated on the oil pan, and the portion of the circulation pipeline may also be the heat transfer portion.

Experimental Example 1 The lubricating oil heating apparatus shown in FIGS.
00kg car (gasoline engine, displacement 2000
cc), put the car in a room at 0 ° C and let it stand for 24 hours, then start the engine, idle for 20 seconds, and then run in 10-15 mode. The difference was confirmed by whether or not the heater was energized (and the circulation pump was operated). However, energization of the heater (and operation of the circulation pump) was performed at the same time when the engine was started. In this experiment, in order to prevent the reduction of friction due to the temperature rise of the lubricating oil and the consumption of fuel due to the increase of idling speed, the same speed is used regardless of whether the heater is energized or not. Controlled to be.

The heater used was a 1.5 kw alumina ceramic heater, the circulation pump had a discharge capacity of 6 l / min, and the radiator water (water: long coolant = 1: 1) to be heated was used. ) Is a total of 15
It is 00 cc. The results are as shown in Table 1.

[0024]

[Table 1]

It can be seen from Table 1 that when the lubricating oil was heated under the above conditions, the fuel consumption was improved by about 3%.

Experimental Example 2 Lubricating oil heating apparatus used in Experimental Example 1 and a lubricating oil heating apparatus in which a 1.5 kw sheathed heater made of alumina and cast on the same engine is fixed to the lower surface of an oil pan with a screw. The apparatus and the heating rate of the lubricating oil were compared. However, in both cases, the heater was energized from the state where the lubricating oil was kept at 20 ° C, and the time until the lubricating oil reached 70 ° C was measured. The engine was kept idling. Result is,
It is as shown in Table 2.

[0027]

[Table 2]

As is clear from Table 2, the experimental example 1 was able to heat the lubricating oil much faster (efficiently) than the case where the alumina cast gurney heater was fixed to the oil pan.

[0029]

According to the present invention, a liquid different from the lubricating oil is heated, and the lubricating oil is heated by the liquid.
The heat generation density can be increased. Therefore, as compared with the heater that is cast into aluminum, it is an indirect heating method, but the lubricating oil can be efficiently heated. Further, according to the present invention, radiator water or the like can be directly heated as the heating medium, but in this case, carbonization is less than in the case of directly heating the lubricating oil, and therefore the heat transfer efficiency is improved. Even if a ceramic heater is used as the heating means, the life of the heater is extended, and the reliability and durability are improved.

Further, according to the method for maintaining the proper temperature of the lubricating oil for the internal combustion engine according to the present invention, the lubricant oil can be reasonably maintained at the appropriate temperature.

[Brief description of drawings]

FIG. 1 is a piping system diagram showing an embodiment of a lubricating oil heating apparatus for an internal combustion engine according to the present invention, in which a heat transfer section is a water-cooled oil cooler.

FIG. 2 is a cross-sectional view of the heater used in FIG.

FIG. 3 is a diagram illustrating a state in which a heating circulation pipe line communicates with FIG. 1.

FIG. 4 is a diagram illustrating a state in which a circulation pipe line for cooling communicates with FIG. 1.

FIG. 5 is a schematic perspective view of an oil pan for explaining an embodiment of a lubricating oil heating apparatus for an internal combustion engine according to the present invention, in which a heat transfer portion is a portion of a circulation pipeline passing through an inside of a cross section of the oil pan. 7A and 7B are views for explaining a circulation pipeline for heating.

6 is an enlarged cross-sectional view taken along the line AA in FIG.

[Explanation of symbols]

 1 Oil Cooler (Heat Transfer Section) 6 Circulation Pipeline for Cooling 7,8 Three-way Valve 10,30 Circulation Pipeline for Heating 12,22 Circulation Pump 11,21 Heating Means (Heater) 31 Oil Pan 14 Ceramic Heater

Claims (5)

[Claims] 1. The liquid circulates through the heat transfer portion so that the lubricating oil of the internal combustion engine is indirectly heated by the liquid such as heated water different from the lubricant oil through the heat transfer portion. Lubrication for an internal combustion engine, comprising: a possible circulation line for heating, a circulation pump for circulating the liquid in the circulation line for heating, and a heating means for heating the liquid. Oil heating device. 2. The lubricating oil heating apparatus for an internal combustion engine according to claim 1, wherein the heat transfer portion is a water-cooled oil cooler provided for cooling the lubricating oil of the internal combustion engine. 3. The circulation line is formed so as to pass through the inside of a cross section of an oil pan of an internal combustion engine or through lubricating oil accumulated on the oil pan, and the heat transfer section has a cross section of the oil pan. 2. The lubricating oil heating apparatus for an internal combustion engine according to claim 1, which is a portion of the circulation line that passes through the lubricating oil accumulated inside or on an oil pan. 4. The lubricating oil heating apparatus for an internal combustion engine according to claim 1, 2 or 3, wherein the heating means is a ceramic heater. 5. A water-cooled oil cooler provided for cooling the lubricating oil of an internal combustion engine, wherein the heated radiator water is circulated when the lubricating oil is below a predetermined temperature. A suitable temperature of the lubricating oil for an internal combustion engine, characterized in that, while the lubricating oil is heated, when the lubricating oil reaches a predetermined temperature, the lubricating oil is cooled by circulating cooled radiator water. Retention method.