JP2001214725A - Device and method for detecting moisture content in lubricating oil - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a device and method for detecting a moisture content in lubricating oil capable of providing a detection result suitable for determining a time to replace the lubricating oil. SOLUTION: The device for detecting the moisture content comprises a detection part 20 for outputting a signal corresponding to the moisture content in the lubricating oil used for lubricating an engine 11, and also comprises ECU 14 for controlling detecting operation of the detection part 20. The ECU 14 detects the moisture content in the lubricating oil based on the signal outputted by the detection part 20 when the engine 11 is determined to be transferred from an operating state to a stopping state.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device and method for detecting the amount of water contained in lubricating oil for detecting the amount of water contained in lubricating oil of an internal combustion engine.

[0002]

2. Description of the Related Art As is well known, when moisture is mixed in the lubricating oil of an internal combustion engine, there is a possibility that rust may be generated in a movable portion of the internal combustion engine. Conventionally, as an apparatus for detecting the amount of water in lubricating oil, an apparatus described in Japanese Patent Application Laid-Open No. 55-110935 is known.

This device has a lubricating oil chamber filled with lubricating oil, and a heater for heating the lubricating oil in the lubricating oil chamber. In this device, the lubricating oil in the lubricating oil chamber is heated by a heater to evaporate the water contained in the lubricating oil, and the volume change in the lubricating oil chamber due to the evaporation is detected. The amount of water in the water is detected.

[0004] For this reason, for example, when the amount of water in the lubricating oil exceeds a predetermined amount, it is possible to know the timing of replacing the lubricating oil in such a manner that rust may occur in the movable part of the internal combustion engine.

[0005]

By the way, it has been confirmed by the present inventors that the water content in the lubricating oil rapidly increases when the engine is started, and thereafter gradually decreases. This is because when the engine is started, the amount of water temporarily increases due to the water in the intake air and the water generated due to the combustion of the fuel being mixed into the lubricating oil. It is considered that when the amount of evaporation of water from the lubricating oil gradually increases with the rise, the amount of evaporation exceeds the mixing amount, and the amount of water also gradually decreases.

For this reason, when the water content in the lubricating oil temporarily increases with the start of the engine, the same water content is detected,
When the timing of replacing the lubricating oil is determined based on the detection result, it is determined that the lubricating oil should be replaced even though each movable part of the engine is sliding and rust is not likely to occur,
There is a possibility that the replacement time of the lubricating oil may be advanced earlier than necessary.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and has as its object to provide a lubricating oil moisture content detecting device capable of obtaining a detection result suitable for judging a time to replace a lubricating oil. And a method for detecting the amount of water.

[0008]

The means for achieving the above object and the effects thereof will be described below. The invention according to claim 1 is a determining means for determining whether the internal combustion engine is in an operating state or a stopped state, and when the internal combustion engine is determined to be in a stopped state by the determining means. A detecting device for detecting the amount of water contained in the lubricating oil constitutes a device for detecting the amount of water in the lubricating oil.

According to a second aspect of the present invention, in the lubricating oil moisture content detecting device according to the first aspect, the detecting means changes the state of the internal combustion engine from an operating state to a stopped state determined by the determining means. A device for detecting the amount of water in the lubricating oil is configured to detect the amount of water when the process shifts to.

According to a third aspect of the present invention, in the lubricating oil moisture amount detecting device according to the first or second aspect, the detecting means includes a detecting unit for outputting a signal corresponding to the moisture amount. The detecting unit is provided in the lubricating oil in the oil pan in which the lubricating oil is stored, and constitutes a device for detecting the water content of the lubricating oil.

The invention according to claim 4 determines whether the internal combustion engine is in an operating state or a stopped state, and when it is determined that the internal combustion engine is in a stopped state, the moisture contained in the lubricating oil of the internal combustion engine is determined. Shall be detected.

According to a fifth aspect of the present invention, it is determined whether the internal combustion engine is in an operating state or a stopped state, and when the determined state of the internal combustion engine shifts from an operating state to a stopped state. The amount of water contained in the lubricating oil of the internal combustion engine is detected.

[0013] When the engine is stopped, the movable parts of the internal combustion engine are not slid and the lubricating oil is not circulated. Also, when the engine is stopped, a decrease in the amount of water in the lubricating oil due to evaporation cannot be expected.

According to the first or fourth aspect of the present invention, the amount of water in the lubricating oil is detected when the engine is in a stopped state. This becomes a more appropriate value for evaluating the possibility of occurrence. Therefore, when detecting the amount of water in the lubricating oil, the detection result can be made suitable for judging the timing of replacing the lubricating oil.

According to the second or fifth aspect of the present invention, the amount of water in the lubricating oil is detected when the internal combustion engine shifts from the operating state to the stopped state. The same water content is detected early. Therefore, when the amount of water in the lubricating oil has reached an amount that causes rust and it is necessary to replace the lubricating oil, it is possible to judge this at an early stage.

Further, according to the configuration of the invention described in the third aspect, a configuration for transporting the lubricating oil from the oil pan to the detection unit becomes unnecessary, and the configuration can be simplified.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIGS. 1 to 3 show an embodiment of a device and a method for detecting a water content of lubricating oil according to the present invention.

First, as shown in FIG. 1, an internal combustion engine (engine) 11 is provided with an oil pan 12 for storing lubricating oil used for lubricating the engine 11, and a lubricating oil for the oil pan 12 when the engine is operating. And a pump 13 for supplying to the pump 11. The engine 11 is operated when the operation position of the ignition switch 15 is at the ON position, and is stopped when the operation position of the switch 15 is switched from the ON position to the OFF position.

On the other hand, the lubricating oil water content detecting device is provided in the lubricating oil in the oil pan 12 and detects a water content in the lubricating oil. And a control device (ECU) 14 to be inputted.

FIG. 2 schematically shows the structure of the detection unit 20. The detection unit 20 is a cylindrical case 2 having a bottom.
1, a valve 25 for opening and closing an opening of the case 21, a partition 22 movably provided in the case 21, and the like. The inside of the case 21 is partitioned by the partition wall 22 into a lubricating oil chamber 23 filled with lubricating oil and an air chamber 24 filled with air. The ECU 14
When the valve 25 is opened and closed at a predetermined timing, the inside of the lubricating oil chamber 23 and the oil pan 12
Is communicated with or interrupted. Therefore, the lubricating oil chamber 23 can be filled with the lubricating oil without providing a separate device such as a pump.

A heater 28 for heating the lubricating oil in the lubricating oil chamber 23 and an oil temperature sensor 29 for detecting the temperature of the lubricating oil are provided in a portion of the case 21 located on the outer periphery of the lubricating oil chamber 23. . Further, the air chamber 24 is provided with a spring 26 for keeping the volume of the lubricating oil chamber 23 constant when the lubricating oil chamber 23 is filled with lubricating oil. The spring 26 has a strain gauge 27 for detecting the amount of elastic deformation thereof.
Is attached.

In detecting the amount of water in the lubricating oil by the detecting unit 20, first, the valve 14 is opened by the ECU 14, and the lubricating oil in the oil pan 12 is introduced into the lubricating oil chamber 23. And for a predetermined period,
After the valve 5 is held in the open state and the lubricating oil in the lubricating oil chamber 23 and the lubricating oil in the oil pan 12 are made homogeneous, the valve 25 is closed and the lubricating oil chamber 23 is sealed. . Thus, the lubricating oil chamber 23 is filled with lubricating oil of the same quality as the oil pan 12.

Thereafter, based on the temperature detected by the oil temperature sensor 29, the temperature of the lubricating oil becomes a predetermined temperature (a temperature at which moisture in the lubricating oil can be vaporized; for example, "100 ° C.").
Until the lubricating oil in the lubricating oil chamber 23 is heated by the heater 28. As a result, the moisture contained in the lubricating oil gradually evaporates. As described above, when moisture in the lubricating oil is vaporized in the lubricating oil chamber 23, the pressure in the lubricating oil chamber 23 increases by an amount corresponding to the amount of vaporization, and
Moves to the air chamber 24 side. That is, the volume in the lubricating oil chamber 23 increases by an amount corresponding to the amount of water contained in the lubricating oil. The amount of elastic deformation of the spring 26 caused by the movement of the partition 22 is detected as the amount of increase in the volume of the lubricating oil chamber 23, that is, the amount of water in the lubricating oil.

Here, a change in the amount of water in the lubricating oil due to the operation of the engine 11 will be described with reference to FIG. As shown in FIG. 3A, when the engine 11 is started, the lubricating oil is mixed with water contained in the intake air and water such as water vapor generated by combustion in the combustion chamber. The amount of water in the lubricating oil temporarily increases (timing t10 to timing t11 in the figure).

Thereafter, when the temperature of the lubricating oil rises with the operation of the engine, the amount of water in the lubricating oil gradually evaporates, so that the amount of water in the lubricating oil decreases (after timing t11 in the figure). ).

Here, as described above, when the water content in the lubricating oil temporarily increases with the operation of the engine 11 (timing t11 in the figure), the same water content is detected, and based on the detection result, When it is determined when to replace the lubricating oil,
It is determined that the lubricating oil should be replaced despite the fact that the movable parts of the engine 11 are less likely to rust due to sliding, and that the water content decreases with the subsequent lubricating oil temperature increase. As described above, the timing of replacing the lubricating oil may be advanced.

On the other hand, as shown in FIG. 3B, after the engine 11 is started, if the engine 11 is repeatedly stopped before the temperature of the lubricating oil rises so much (at timing 20 in the figure). -T23), a large amount of water remains in the lubricating oil.

As described above, when the engine 11 is stopped in a state where the amount of water in the lubricating oil is increased, the movable parts thereof do not slide, and the lubricating oil is circulated. Since it is in a state without water, and since the amount of water does not decrease thereafter, rust is more likely to occur than in operation.

Therefore, in the present embodiment, the engine 11
Specifically, when the engine 11 shifts from the movable state to the stopped state, the amount of water in the lubricating oil is detected.

Specifically, when the ECU 14 determines that the engine 11 is stopped, that is, when the operation position of the ignition switch 15 is switched from the on state to the off state, the ECU 14 operates the detection unit 20 in the manner described above. By controlling and reading the output signal, the amount of water in the lubricating oil is detected. Therefore, the amount of moisture detected in this way is appropriate for evaluating the possibility of rust occurring in the engine 11. Therefore, if the timing of replacing the lubricating oil is determined based on the amount of water in the lubricating oil, the lubricating oil can be replaced at an appropriate time to avoid the generation of rust.

As described above, according to the lubricating oil moisture detecting apparatus and method of the present embodiment, the following excellent effects can be obtained. (1) Since the water content of the lubricating oil is detected when the engine 11 is stopped, the detected water content is appropriate as a value for evaluating the possibility of rust occurring in the engine 11. . Therefore, when detecting the amount of water in the lubricating oil, the detection result can be made suitable for judging the timing of replacing the lubricating oil.

(2) In particular, since it is determined that the engine 11 has transitioned from the operating state to the stopped state and the amount of water in the lubricating oil is detected, the detection can be performed earlier when the engine is stopped. become able to. Therefore,
If the amount of water in the lubricating oil has reached an amount that causes rust and replacement of the lubricating oil is necessary, this can be determined at an early stage.

(3) Further, the detecting unit 20 is connected to the oil pan 12
The oil pan 1
There is no need to separately provide a mechanism for transporting the lubricating oil from 2 to the detection unit 20, and the configuration can be simplified.

The above embodiment can be implemented by changing its configuration as follows. In the above-described embodiment, when the engine 11 shifts from the operating state to the stopped state, the amount of water in the lubricating oil is detected based on the output signal of the detection unit 20. Any timing can be set.

In the above embodiment, the change in the volume in the lubricating oil chamber 23 is detected by the strain gauge 27 attached to the spring 26 provided in the partition 22. However, the change in the volume can be detected. As long as the spring 26 changes its electrical resistance due to its compression, any change may be detected.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram showing a water content detection device according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view showing a side cross-sectional structure of a detection unit in the water content detection device.

FIG. 3 is a timing chart showing an example of a change in the amount of water in lubricating oil due to engine operation.

[Explanation of symbols]

11 ... engine, 12 ... oil pan, 13 ... pump, 1
4 ECU, 20 detection part, 21 case, 22 partition wall, 23 lubricating oil chamber, 24 air chamber, 25 valve, 26 ...
Spring, 27: strain gauge, 28: heater, 29: oil temperature sensor.

Claims (5)

[Claims] And a judging means for judging whether the internal combustion engine is in an operating state or a stopped state, and applying lubricating oil to the internal combustion engine when the judging means judges that the internal combustion engine is in a stopped state. Detecting means for detecting the amount of water contained in the lubricating oil. 2. The lubricating oil water content detecting device according to claim 1, wherein said detecting means is configured to detect said water content when the state of said internal combustion engine determined by said determining means shifts from an operating state to a stopped state. A device for detecting the water content of lubricating oil, characterized by detecting the following. 3. The lubricating oil water content detecting device according to claim 1, wherein said detecting means includes a detecting unit for outputting a signal corresponding to said water amount, wherein said detecting unit stores said lubricating oil. A device for detecting the water content of lubricating oil, wherein the device is disposed in lubricating oil in an oil pan. 4. A method according to claim 1, further comprising determining whether the internal combustion engine is in an operating state or a stopped state, and detecting an amount of water contained in the lubricating oil of the internal combustion engine when it is determined that the internal combustion engine is in the stopped state. Method for detecting the moisture content of lubricating oil. 5. A method for determining whether the internal combustion engine is in an operating state or a stopped state, and including the lubricating oil of the internal combustion engine when the determined state of the internal combustion engine shifts from an operating state to a stopped state. A method for detecting the amount of water in lubricating oil, comprising detecting the amount of water to be discharged.