JP3365462B2 - Internal combustion engine lubrication system - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lubricating device for an internal combustion engine, and more particularly to a lubricating device for an internal combustion engine which removes bubbles mixed in lubricating oil.

[0002]

2. Description of the Related Art A conventional internal combustion engine lubricating device is, for example,
As disclosed in Japanese Patent Laid-Open No. 60-53608, an oil pan of a lubricating device is attached to the lower part of the engine, and the lubricating oil is stored therein. Then, an oil filter and an oil pump driven by the engine are installed in the oil pan, and the lubricating oil is supplied to each lubricating portion of the engine through an oil passage pipe.

[0003]

However, during operation of the engine, the lubricating oil that has finished lubrication falls from the upper part into the oil pan, and at this time air is entrained in the lubricating oil in the oil pan. Further, the lubricating oil is scattered due to the influence of the rotating portion and the lubricating oil in the oil pan is rolled up, which causes an increase in inclusion of bubbles in the lubricating oil. If the lubricating oil containing air bubbles is sucked into the oil pump from the strainer and pressure-fed to each part of the engine, there is a possibility that lubrication failure or seizure may occur in the bearing part. Further, when a variable device such as a variable valve timing mechanism that uses lubricating oil is provided, there is a problem in that a malfunction may occur.

Therefore, the present invention has been made in view of the above problems of the prior art, and an object of the present invention is to determine whether or not air bubbles are mixed in the lubricating oil and to make the bubbles from the lubricating oil. It is intended to provide a lubrication device for an internal combustion engine, in which

[0005]

In order to solve the above problems, a lubricating device for an internal combustion engine according to the present invention is provided with an oil passage pipe through which lubricating oil flows, and bubbles mixed in the lubricating oil disposed in the oil passage pipe. And a determination circuit that determines whether or not air bubbles are mixed based on the output of the detection unit, and when the detection unit heated by current is transferred and cooled by the lubricating oil, the lubricating oil It is characterized in that the difference between the temperatures of the detection unit is generated between the bubbles and the bubbles, and the detection unit converts the temperature into a voltage and outputs the voltage to the determination circuit. A bypass pipe is provided in the oil passage pipe via a switching valve, and a gas-liquid separator is provided in the bypass pipe. Upon operation, the oil passage pipe and the bypass pipe communicate with each other, and the gas-liquid separation device separates bubbles in the lubricating oil.

Further, the lubricating device has an oil pan for storing the lubricating oil, and an auxiliary oil pump for supplying the lubricating oil from the sub oil tank to the oil pan, and by operating the auxiliary oil pump, The level of the lubricating oil in the oil pan is controlled. Further, the lubrication device has an alarm device for informing that the amount of bubbles mixed in the lubricating oil is a certain amount or more.

The detecting portion has a thin metal wire which is a conductor. Further, the detection unit may have a thermistor. Further, the determination circuit outputs a signal to operate the switching valve or the auxiliary oil pump when it is determined that the amount of mixed bubbles is large when the amount of mixed bubbles in the lubricating oil exceeds the allowable value. ing.

Next, the operation of the lubricating device for an internal combustion engine of the present invention will be described. Lubricating oil is flowing through the oil passage of the lubricating device, and the oil passage is provided with a detection unit for detecting inclusion of bubbles in the lubricating oil. Then, when electricity is applied to the detecting portion, heat is generated due to electric resistance, but the temperature is stabilized at a value at which heat transfer to the surrounding lubricating oil and cooling from the lubricating oil are balanced. Therefore, if the current to the detection unit is constant and the flow velocity of the lubricating oil is constant, the temperature of the detection unit will rise significantly when a bubble having a specific heat smaller than that of the lubricating oil comes into contact with the detection unit. As a result, the output voltage of the detector changes. The presence or absence of bubbles in the lubricating oil can be determined by the difference between the temperature when the lubricating oil contacts the detector and the temperature when the bubbles contact the detector, that is, the change in the output voltage of the detector. Now, when bubbles are mixed in the lubricating oil flowing through the oil passage, the output of the detection unit changes and is input to the determination circuit. Then, when the output of the detection unit exceeds the predetermined allowable value of the amount of mixed bubbles in the determination circuit, it is determined that the amount of mixed bubbles is large. Then, the switching valve is switched by the output signal from the determination circuit, and the lubricating oil in which bubbles are mixed is introduced into the gas-liquid separation device to separate the bubbles. Further, when the air bubbles are significantly mixed, the output signal from the determination circuit is input to the auxiliary oil pump to operate the auxiliary oil pump, and the lubricating oil is supplied to the oil pan and the air is not sucked. In addition, an alarm device is activated if the bubbles do not decrease.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described below with reference to FIG. FIG. 1 is a system configuration diagram of a lubricating device for an internal combustion engine according to the present invention. In FIG.
A strainer 2 is provided in an oil pan 1 that is attached to a lower portion of an engine (not shown) and stores lubricating oil.
An oil pump 3, which is driven by the engine and guides the lubricating oil in the oil pan 1 to each part of the engine, is connected to a downstream side portion of the strainer 2 through an oil passage pipe 5. An oil filter 6 is provided on the downstream side of the oil pump 3, and a switching valve 7 is provided on the downstream side. The switching valve 7 is for switching the oil passage pipe 5 to the bypass pipe 8 for communication. Further, a gas-liquid separator 10 for separating bubbles in the lubricating oil is provided in the middle of the bypass pipe 8, and the downstream side of the oil passage pipe 5 is branched so that the variable mechanism is hydraulically operated. The lubricating oil flows to the valve train, the crankshaft bearing and the valve train. Furthermore,
The lubricating oil that has finished lubrication becomes oil droplets or travels down the wall and falls into the oil pan 1 again. On the other hand, when the air bubbles are significantly mixed, it is considered that the liquid level in the oil pan 1 is lowered. Therefore, the auxiliary oil is stored from the sub oil tank 11 that stores the auxiliary lubricating oil, and the auxiliary oil pump 12 is operated to supply the lubricating oil from the sub oil tank 11 to the oil pan 1. In addition, the detection unit 1 of the bubble detection device is provided at an intermediate position in the oil passage 5 through which lubricating oil flows between the oil filter 6 and the switching valve 7.
5 are provided. An amplification circuit 16 is connected to the detection unit 15, and an output signal detected by the detection unit 15 is amplified and output to the determination circuit 17. In the judgment circuit 17, the detection signal of the detection unit 15 is judged, and the switching valve 7 and the auxiliary oil pump 12 are operated, and the alarm device 18 is operated.

The detecting portion 15 is made of a thin metal wire which is a conductor and is arranged in the flow of lubricating oil. Detector 1
When electricity is applied to No. 5, heat is generated due to the electric resistance of the thin metal wire, but the temperature is stabilized at a value that balances heat transfer to the surrounding lubricating oil and cooling from the lubricating oil. Therefore, if the current to the detecting unit 15 is constant and the flow velocity of the lubricating oil is constant, bubbles having a smaller specific heat than the lubricating oil flow and the detecting unit 15
When it contacts with, the temperature of the detection unit 15 greatly rises. Therefore, by grasping the rise of the temperature as the rise of the electric resistance value by the amplification circuit 16, whether only the lubricating oil or the bubbles are mixed in the lubricating oil is detected. Can be determined. On the other hand, when a semiconductor such as a thermistor is used for the detection unit 15, the electric resistance value decreases as the temperature rises, but it is also possible to determine whether the oil is lubricating oil or mixed bubbles based on the difference in the electric resistance value. Therefore, since the temperature of the detection unit 15 is constant and the electric resistance value is also constant if the flow rate of the lubricating oil is constant and there is no air bubble inclusion, the detection unit output (V) is as shown in FIG. 2 (A). It is constant. However, when air bubbles are mixed in the lubricating oil,
When flowing through the oil passage pipe 5, the detection unit output (V) is as shown in FIG.
As shown in (B), the bubbles fluctuate each time they contact the detection unit. The fluctuation of the detection unit output (V) is detected to measure the amount of mixed bubbles. Then, when the fluctuation amount or the number of fluctuations of the detection unit output (V) exceeds the predetermined allowable value of the bubble mixing amount, it is determined that the mixing bubble amount is large. And
When the determination circuit 17 determines from the output signal of the detection unit 15 that the amount of air bubbles is large, the switching valve 7 is operated by the output signal from the determination circuit 17 to connect the oil passage pipe 5 to the bypass pipe 8. The lubricating oil flowing through the oil passage pipe 5 is introduced into the gas-liquid separation device 10. The gas-liquid separation device 10 separates air bubbles mixed in the lubricating oil and flows only the lubricating oil to each lubricating portion of the engine.

It is considered that one of the causes of the inclusion of air bubbles in the lubricating oil is the deterioration of the oil level of the oil pan 1. At this time, there are cases where the air is sucked directly from the strainer 2 and cases where the air to be mixed cannot be separated and is sucked when the lubricating oil drops violently into the oil pan 1. In such a case, bubbles are significantly mixed in the lubricating oil. As a measure against this,
The auxiliary oil pump 12 is operated by the output signal from the determination circuit 17 to replenish the lubricating oil in the sub oil tank 11 to the oil pan 1 to control the oil level. Further, if the inclusion of air bubbles does not decrease even when the auxiliary oil pump 12 is operated, the alarm device 18 is operated by the output signal from the determination circuit 17 to notify the driver.

Next, the detector of the lubricating device for an internal combustion engine according to the present invention will be described in more detail. FIG. 3 is a partial cutaway explanatory view for explaining in detail a first embodiment of the detection unit applied to the lubricating device of the present invention, and FIG. 3A is a front view of the detection unit. 3B is a cross-sectional view of the detection unit. Further, the same reference numerals are given to the structural parts common to the above-mentioned embodiments, and the duplicated description will be omitted. The same applies to other embodiments described below. In FIG. 3, the thin metal wire 21 of the detection unit 15 is supported by the ends of two parallel columns 22 and 22 and is horizontally stretched in the oil passage at the substantially central portion of the oil passage pipe 5. Also,
The columns 22, 22 are insulated from the engine body by an insulator 23. FIG. 4 shows a second embodiment of the detection unit applied to the lubricating device of the present invention, and FIG.
4B is a front view of the detection unit, and FIG. 4B is a cross-sectional view of the detection unit. The thin metal wire 21 of the detection unit 15 is supported by the tip ends of two parallel columns 22, 22 that are bent back and forth in the lubricating oil flow direction, and is perpendicular to the oil passage in the approximate center of the oil passage 5. It is stretched over. In addition, the supports 22 and 22 are insulators 23.
Is insulated from the engine body. FIG. 5 shows a third embodiment of the detection unit applied to the lubricating device of the present invention, and FIG. 5 (A) is a front view of the detection unit.
(B) is a cross-sectional view of the detection unit. The thin metal wire 21 of the detection unit 15 is supported by the tips of the two columns 22, 22 that are vertically opposed to each other on the same axis, and is vertically stretched in the oil passage in the substantially central portion of the oil passage 5. It is hung. In any of the embodiments, since the output signal value changes depending on the direction of the detection unit 15 with respect to the flow direction of the lubricating oil, it is necessary to keep the metal thin wire 21 fixed in the mounting direction with respect to the oil passage of the oil passage 5. .

Further, another embodiment of the detecting portion applied to the embodiment of the lubricating device for an internal combustion engine of the present invention shown in FIG. 1 will be described with reference to FIGS. 6 and 7. FIG. 6 is a partially omitted explanatory view showing, in an enlarged manner, another first embodiment of the detection unit.
6A is a front view, and FIG. 6B is a cross-sectional view for explaining the detection unit by cutting along the line AA of FIG. 6A. The detector shown in FIG. 6 uses a conductor thin film 25 in place of the thin metal wire 21 used in FIGS. 3 to 5, and the hollow conductor thin film 25 is filled with an insulator 24. The same effect as that of the thin metal wire 21 can be obtained. Further, FIG. 7 is a partially omitted explanatory view showing an enlarged second embodiment of the detection unit. The detection unit shown in FIG. 7 uses the conductor thin film 25 similarly to the detection unit shown in FIG. 6, and the sensor unit including the conductor thin film 25 in the vicinity of the tip of the insulating support column 22 protruding to the front in the lubricating oil passage. Is provided, and it is possible to achieve the same effect as that of the thin metal wire 21. In the figure, 26 is a lead wire.

Next, the gas-liquid separation device in the lubricating device for an internal combustion engine of the present invention will be described in more detail. FIG. 8 is a perspective view for explaining in detail a first embodiment of a gas-liquid separation device applied to a lubricating device for an internal combustion engine of the present invention. As shown in FIG. 8, a bypass pipe 28 for allowing lubricating oil mixed with air bubbles to flow in is provided on the upper side surface of the cylindrical container 27 of the cyclone type gas-liquid separator. When the lubricating oil mixed with bubbles is introduced from the bypass pipe 28 arranged on the upper side surface of the cylindrical container 27, the bypass pipe 28 is arranged so as to be offset from the center of the cylindrical container 27. A swirl flow is generated in the center of the cylindrical container 27. In addition, the cylindrical container 27
A bypass pipe 30 for flowing out only the lubricating oil from which bubbles have been separated is disposed on the lower side surface of the. On the other hand, at the center of the upper end of the cylindrical container 27, a gas separation control valve 31 for releasing the gas collected above the center of the cylindrical container 27 to the outside is installed. When the bubble-containing lubricating oil flows into the cylindrical container 27 from the bypass pipe 28, the bubble-containing lubricating oil turns into a swirling flow and swirls in the cylindrical container 27. Due to this swirling flow, a centrifugal force is generated in the bubble-containing lubricating oil, and the bubbles lighter than the lubricating oil are separated from the lubricating oil and are gathered upward in the central direction. Then, by opening the gas separation control valve 31, the cylindrical container 2
Since only the gas collected near the upper center of 7 is discharged to the outside, only the lubricating oil without bubbles can flow out from the bypass pipe 30.

FIG. 9 is a perspective view for explaining in detail the second embodiment of the gas-liquid separating device applied to the lubricating device for the internal combustion engine of the present invention. As shown in FIG. 9, a bypass pipe 28 for allowing the lubricating oil mixed with bubbles to flow in is disposed above the cylindrical container 27 of the flow velocity control gas-liquid separator. Further, a bypass pipe 30 is provided on the lower peripheral surface of the cylindrical container 27 so as to flow out only the lubricating oil from which the air bubbles have been separated. On the other hand, in the cylindrical container 27, a plurality of disc-shaped plates 33 having a large number of small holes 32 are installed at predetermined intervals. Then, when the bubble-containing lubricating oil passes through the large number of small holes 32 of the disc-shaped plate 33, the flow velocity of the lubricating oil decreases and bubbles hardly pass through the small holes 32, so that the lubricating oil is separated from the lubricating oil and goes upward. Gather. Since the plurality of disc-shaped plates are installed, the bypass pipe 28 disposed on the lower peripheral surface of the cylindrical container 27 is provided.
Only lubricating oil without bubbles can flow out from the.
Further, by opening the gas separation control valve 31 installed at the center of the upper end of the cylindrical container 27, the cylindrical container 27
The bubbles gathered in the upper part can be discharged to the outside.

Next, the operation of the embodiment of the present invention will be described based on the flowchart shown in FIG. When the engine is started, the operation of this apparatus is started (start), and in step 101, signals such as engine speed and oil temperature are read. Then, in step 102, the detecting unit 1
Only the lubricating oil when no bubbles are mixed in 5 is flowed, and the determination circuit 17 calibrates the output of the detection unit when no bubbles are mixed based on the signals such as the engine speed and the oil temperature to obtain an expected output value. Calculate it. Alternatively, since the temperature of the detection unit 15 can be predicted from the balance between the amount of heat supplied by the current and the amount of heat transferred to the lubricating oil, the predicted output value can be calculated from the temperature and the like. Further, in step 103, the actual detection unit output value is detected. Next, in step 104, the calculated expected output value and the actual output value are compared. And. When the fluctuation of the detector output (V) due to air bubbles exceeds the allowable value. ． When the number of output fluctuations is calculated and the number of output fluctuations per unit time is large. ． When the calculated expected output value is out of the allowable value band for a long time. When the above conditions are met, it is determined that the amount of mixed bubbles is large, and the lubricating oil control is performed or an alarm device is used to notify. Which of the above conditions is used for the determination is set in advance. And step 1
When it is determined in 04 that the amount of mixed bubbles is large,
Proceeding to step 105, the switching valve 7 is operated to connect the oil passage pipe 5 and the bypass pipe 8. And the gas-liquid separation device 1
The lubricating oil mixed with bubbles is guided to 0 to separate the bubbles, and only the lubricating oil having no bubbles is flowed out and the lubricating oil is supplied to each engine portion to be lubricated. Next, in step 106, when it is determined that bubbles are significantly mixed in the lubricating oil,
In step 107, the auxiliary oil pump 12 is operated to replenish the lubricating oil from the sub oil tank 11 to the oil pan 1 to control the oil level and prevent the intake of air from the strainer 2. If it is determined in step 108 that the bubbles have not yet decreased, the process proceeds to step 109, where the alarm device 18 is used to notify the driver or the state of the bubble inclusion amount is displayed. Further, in step 104, if the amount of bubbles mixed in the lubricating oil is within the range of the allowable values of ,, and, in steps 106 and 108, the amount of bubbles mixed in the lubricating oil is ,,,.
If it is within the allowable value range of, the process returns to the start, and the same operation is repeated thereafter.

[0017]

Since the present invention is constructed as described above, it has the following effects.

The amount of bubbles mixed in the lubricating oil flowing through the oil passage pipe is
When it is determined by the determination circuit that the amount of bubbles mixed exceeds the planned allowable value, the bubbles can be separated from the lubricating oil by the operation of the gas-liquid separator. In addition, when air bubbles are significantly mixed in the lubricating oil, the auxiliary oil pump is operated to supply the lubricating oil to the oil pan, so that air is not sucked. Further, when the bubbles in the lubricating oil do not decrease, the alarm device gives an alarm so that the driver can stop the operation of the device. Therefore, lubricating oil that does not contain air bubbles is supplied to each part of the engine to be lubricated, and it is possible to prevent poor lubrication and seizure in the bearing part. Further, when the variable device such as the variable valve timing mechanism using the lubricating oil is provided, it is possible to ensure the safety of the device as a whole without causing malfunction.

[Brief description of drawings]

FIG. 1 is a system configuration diagram of a lubricating device for an internal combustion engine according to the present invention.

FIG. 2 is a graph showing the relationship between the output of the detection unit and time, FIG. 2 (A) is a graph showing the case where there is no bubble or a small amount of bubble, and FIG. It is a graph which shows a case.

3A and 3B are partially cutaway explanatory views for explaining the first embodiment of the detection unit in detail, FIG. 3A is a front view of the detection unit, and FIG. 3B is a sectional view of the detection unit. Is.

4A and 4B are partially cutaway explanatory views for explaining the second embodiment of the detection unit in detail, FIG. 4A is a front view of the detection unit, and FIG. 4B is a sectional view of the detection unit. Is.

5A and 5B are partially cutaway explanatory views for explaining the third embodiment of the detection unit in detail, FIG. 5A is a front view of the detection unit, and FIG. 5B is a sectional view of the detection unit. Is.

6A and 6B are partially cutaway explanatory views showing, in an enlarged manner, another first embodiment of the detection unit. FIG. 6A is a front view and FIG. 6B is A in FIG. 6A. It is sectional drawing for demonstrating the said detection part cut | disconnected along the A line.

FIG. 7 is a partially cutaway explanatory view showing another enlarged second embodiment of the detection unit.

FIG. 8 is a perspective view for explaining the first embodiment of the gas-liquid separator in detail.

FIG. 9 is a perspective view for explaining the second embodiment of the gas-liquid separator in detail.

FIG. 10 is a flowchart showing the operation of the embodiment of the present invention.

[Explanation of symbols]

1 ... Oil pan 5 ... Oil pipe 7 ... Switching valve 8 ... Bypass pipe 10 ... Gas-liquid separation device 11 ... Sub oil tank 12 ... Auxiliary oil pump 15 ... Detector 17 ... Judgment circuit 18 ... Alarm device 21 ... Fine metal wire 25 ... Conductor thin film

─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Naoya Kato 14 Iwatani, Shimohakaku-cho, Nishio-shi, Aichi Japan Auto Parts Research Institute (72) Inventor Toru Yoshinaga 14 Iwatani, Shimohakaku-cho, Nishio-shi, Aichi Stock Company Japan Automobile Parts Research Institute (72) Inventor Tokio Obama 14 Iwatani, Shimohakaku-cho, Nishio-shi, Aichi Japan Auto Parts Research Institute (72) Inventor Toru Saito 14 Iwatani, Shimohakaku-cho, Nishio-shi, Aichi Japan Motor Co., Ltd. Part Research Institute (72) Inventor Takashi Kikuchi 1 Toyota-cho, Toyota-shi, Aichi Toyota Motor Co., Ltd. (56) References JP-A-51-9498 (JP, A) SAI 64-64747 (JP, U) Actual development Sho 58-20313 (JP, U) (58) Fields investigated (Int.Cl. ⁷ , DB name) F01M 11/03 F01M 11/10 F01M 11/00

Claims (5)

(57) [Claims] 1. A lubrication system for an internal combustion engine, the lubricating apparatus, through the oil passing tube lubricating oil flows, the switching valve to the communicating oil pipe
Bypass pipe with a gas-liquid separator
And a detection unit disposed in the oil passage for detecting the inclusion of bubbles in the lubricating oil, and a determination circuit for determining whether or not the bubbles are included based on the output of the detection unit, which is heated by an electric current. Taking advantage of the fact that the temperature of the detection unit differs between the lubricating oil and the air bubbles when the detection unit is heat-transferred / cooled by the lubricating oil, the detection unit converts the temperature into a voltage and outputs it to the determination circuit. Output and the above judgment circuit contains air bubbles in the lubricating oil
When the amount exceeds the allowable value, it is determined that the amount of mixed bubbles is large.
Output a signal to activate the above switching valve,
By the operation of the above, the oil passage pipe and the bypass pipe communicate with each other ,
A lubricating device for an internal combustion engine, characterized in that bubbles in lubricating oil are separated by the gas-liquid separating device. 2. A lubricating device for an internal combustion engine, the lubricating device comprising: an oil pan for storing lubricating oil;
Auxiliary oil pump that supplies lubricating oil from the sub oil tank
And an oil passage pipe through which the lubricating oil flows, a detection unit disposed in the oil passage pipe for detecting the inclusion of bubbles in the lubricating oil, and the output of the detection unit determines whether or not the bubbles are included. The detection circuit consists of a judgment circuit, and when the detection part heated by electric current is transferred and cooled by the lubricating oil, the difference in the temperature of the detection part between the lubricating oil and the air bubbles is utilized. Converted to voltage and output to the judgment circuit,
The road is mixed when bubbles in the lubricating oil exceed the allowable value.
It is judged that the amount of bubbles formed is large and the auxiliary oil pump described above is
Outputs a signal to operate and activates the above auxiliary oil pump
By controlling the liquid level of the lubricating oil in the oil pan, a lubricating device for an internal combustion engine is provided. Wherein said lubricating device, the lubricating system of an internal combustion engine according to claim 1, wherein further comprising a warning device to notify that mixing of the bubble is equal to or greater than a predetermined amount of the lubricating oil. Wherein said detector is a lubricating device for an internal combustion engine according to claim 1, wherein it has a thin metal wire which is a conductor. Wherein said detector is a lubricating device for an internal combustion engine according to claim 1, wherein it has a thermistor.