JPH09325099A - Device for measuring insoluble content in lubricating oil - Google Patents

Abstract

PROBLEM TO BE SOLVED: To measure grain concentration, with high precision, of insoluble content in a lubricating oil. SOLUTION: A measurement device M comprises a flow-in channel 2 for taking out a pressurized lubricating oil from an oil line 1 of an internal combustion engine, a measurement chamber 14 provided with a sensor 15 which, connected to its lower stream side, detects concentration of insoluble content in the lubricating oil by light, an oil pressure control part 4 which, connected to its lower stream side, controls the pressure of lubricating oil in the measurement chamber 14, etc. The oil pressure control part 4 can be constituted with, for example, an oil pressure adjusting valve 20 which comprises a ball-like valve body 18 and a spring 19 for urging it and a fixed stop 21. The oil pressure adjusting valve 20 opens/closes according to the lubricating oil pressure in the measurement chamber 14, so acting as to maintain the pressure of lubricating oil at a constant level. Bubbles contained in the lubricating oil within the measurement chamber 14 is compressed and reduced under the pressure, resulting in no reflection and scattering of sensor light, for improved precision of the measurement device M.

Description

Detailed Description of the Invention

[0001]

The present invention relates to a method for reducing the concentration of insoluble components such as relatively large carbon particles (suits) contained when a lubricating oil such as engine oil is deteriorated by long-term use. The present invention relates to a device for measuring insoluble matter in lubricating oil for measuring with high accuracy.

[0002]

2. Description of the Related Art Since lubricating oils such as engine oils contain a dispersant as one of additives, the lubricating performance is improved even when foreign substances such as fine carbon particles are slightly mixed while the oil is fresh. There is no problem, but as the oil gets older, the dispersant gradually wears out and becomes ineffective,
Fine foreign matter agglomerates and grows into something like large carbon particles (suits), which becomes insoluble and lowers the lubrication performance of the oil. If deteriorated oil containing a large amount of undissolved components is used, abrasion of the sliding portion inside the engine becomes severe, and the life of the engine is shortened. Therefore, it is necessary to monitor how much insoluble matter is contained in lubricating oil such as engine oil, and the concentration of insoluble matter indicates the degree of deterioration of engine oil. As a matter of fact, it is desirable to change the oil promptly when the concentration exceeds a predetermined value.

For this reason, Japanese Patent Application Laid-Open No. 7-20049 discloses an apparatus for detecting the concentration of insoluble components in lubricating oil such as engine oil. In this detection device, a light-emitting portion and a light-receiving portion are attached to the left and right symmetric inclined surfaces at the top of a prism having a pentagonal cross section, and the bottom surface of the prism is brought into contact with engine oil which is a liquid to be inspected. When light is emitted from the light emitting unit toward the bottom of the prism at the incident angle where total reflection occurs, a part of the light enters the oil as evanescent waves from the bottom of the prism and is reflected by a relatively shallow layer. The light returns to the prism again and reaches the light receiving section together with the total reflected light. At that time, a part of the evanescent wave hits the insoluble particles in the oil and is absorbed, so that the amount of light reaching the light receiving section is reduced. Since the amount of light emitted from the light emitting unit is reduced, the concentration of the insoluble portion in the oil is calculated from the degree of the reduction. In addition to the above conventional techniques, there is a technique for measuring a change in light transmittance in a lubricating oil in order to measure the concentration of an insoluble component in the lubricating oil for the same purpose.

Each of these measuring devices for the insoluble matter contained in engine oil is attached to an automobile engine, and the concentration of suit contained in engine oil is, for example, 3%.
When it reaches a certain value such as%, it was developed as a warning device that lights a warning light to inform the driver that it is time to change oil. You don't need it. Therefore, it is possible to roughly grasp the target time of oil change, but the accuracy of the measurement result is not very high,
It is not suitable for use as a measuring instrument for accurately measuring the concentration of suits in lubricating oil.

[0005]

In the prior art,
There is no attempt to control the flow rate by keeping the temperature of the engine oil flowing into the detection device or the temperature of the sensor constant, or by controlling the pressure of the engine oil flowing in. A further problem is that no consideration is given to air bubbles mixed in the engine oil. There are many opportunities for air bubbles to be mixed into the engine oil while the engine oil circulates in the engine, depending on the influence of the measured engine oil temperature, pressure, or flow rate on the measurement accuracy. Since air bubbles mixed in engine oil reflect or scatter light, this type of measuring device in which light is made to enter engine oil and the amount of transmitted light or reflected light is detected by an optical sensor. In, the reflection and scattering of light by the bubbles will cause a large error in the measurement result.

As described above, the amount of air bubbles contained in lubricating oil such as engine oil, together with the temperature, pressure and flow rate of engine oil, is a major factor that affects the detection accuracy of the measuring device. Focusing on these factors that have not been a problem in the prior art, an improved insoluble matter measurement that can measure the concentration of insoluble matter in lubricating oil with high accuracy with a relatively simple configuration. The purpose is to provide a device.

[0007]

According to the present invention, there is provided, as a means for solving the above-mentioned problems, an apparatus for measuring an insoluble content in lubricating oil as described in each of the claims.

According to the first aspect of the present invention, the pressurized lubricating oil taken out from the oil line of the internal combustion engine flows into the measuring chamber through the inflow passage. The measurement of the concentration of the insoluble component in the lubricating oil is performed by a sensor using light provided in the measurement chamber. The pressure of the lubricating oil in the measurement chamber is generated when the hydraulic control unit connected to the downstream side throttles the passage of the lubricating oil flowing to the outflow passage. At that time,
Since the hydraulic control unit controls the pressure of the lubricating oil in the measurement chamber to the highest possible constant value, the bubbles contained in the lubricating oil in the measurement chamber are compressed and contracted to reflect light. It will not be scattered. Therefore, the measured value of the concentration of the particles of the insoluble matter detected by the sensor is highly accurate because it is not affected by the bubbles.

According to the second aspect of the present invention, the hydraulic control section can be configured by the hydraulic pressure adjusting valve. According to the third aspect, the hydraulic pressure controlling valve and the fixed throttle can be used. You can In either case, the controlled lubricating oil pressure can be generated in the measurement chamber by opening / closing the oil pressure adjusting valve, and when a fixed throttle is used, a part of the action is performed by the fixed throttle.

As the hydraulic pressure regulating valve, a check valve type valve having a ball-shaped valve body and a spring for urging the valve body toward the valve seat can be used as the simplest structure. In this type of hydraulic control valve, if the pressure of the lubricating oil in the measurement chamber becomes high, the ball-shaped valve element will move farther from the valve seat against the spring and the valve opening amount will increase in accordance with the pressure. , It acts to maintain the lubricating oil pressure in the measuring chamber at a constant height.

According to the solving means of the fifth aspect, a solenoid valve inserted between the measuring chamber and the outflow passage is used as the hydraulic pressure adjusting valve. In this case, the solenoid valve opens for a long time or the opening becomes large when the lubricating oil pressure in the measurement chamber is high.
When the lubricating oil pressure is low, the valve is opened for a short time, or the opening is reduced, so that the lubricating oil pressure in the measurement chamber is opened and closed.

According to the sixth aspect of the invention, the oil temperature control section is provided in a part of the inflow passage for feeding the lubricating oil to the measuring chamber. The oil temperature control unit operates so that the temperature of the lubricating oil in the measurement chamber becomes constant by heating or cooling the lubricating oil. As a result, the lubricating oil at a constant temperature can be measured under the same conditions at any time, so the temperature of the sensor will also be constant, and there will be no difference in the bubble entrapment rate, so there will be no difference in the accuracy of the temperature. High measurements can be made.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION A first embodiment of the present invention will be described with reference to FIGS. As shown in an enlarged view in FIG. 1, a device M for measuring an insoluble matter in lubricating oil as an embodiment includes an internal combustion engine, which is arranged in series in order from the upstream side to the downstream side of the lubricating oil flow. Inflow passage 2 connected to E oil line 1 and measuring unit 3 whose configuration will be described later in detail.
And a hydraulic control unit 4 and the like connected to the downstream side thereof. Although not shown in the drawing, an electronic measurement or control device including, for example, a microprocessor is provided in order to perform necessary calculation based on the detection signal of the measurement unit 3 and other control operations. There are cases.

On the other hand, as shown in FIG. 2, in the internal combustion engine E which is operated by using the lubricating oil whose concentration of the insoluble matter is to be measured by the measuring device M as in the embodiment, the oil pan 5 to the strainer are used. The lubricating oil pumped through the oil pump 7 and pressurized to a predetermined hydraulic pressure through
The oil is distributed to a large number of branch lubricating oil passages 8 branched from the oil line 1 described above, and lubrication of the periphery of the piston 9 and the camshafts 10, 11 or bearings is required by these branch lubricating oil passages 8, 8. The lubricating oil is supplied to the portion to be turned. The measuring device M takes out a part of the lubricating oil circulating inside the internal combustion engine E from the common oil line 1 and measures the concentration of the insoluble matter contained therein, but the measurement is completed. An outflow passage 12 is provided for sending back the lubricating oil after being fed to the oil pan 5.

The measuring unit 3 in the first embodiment is shown in FIG.
As shown in FIG.
The measuring chamber 14 receives the lubricating oil from the inflow passage 2 branched from the oil line 1 and the sensor 15 for utilizing the light, which is mounted so that the detection end 22 faces the inside. The measurement chamber 14 is provided with an inlet portion 16 into which the lubricating oil is received from the inflow passage 2 and an outlet portion 17 through which the lubricating oil flows out to the hydraulic control unit 4 on the downstream side. As the sensor 15, for example, a sensor similar to the liquid property detecting device provided with a prism as described in JP-A-7-20049 can be used.

The outlet section 1 of the measuring chamber 14 is used as a constituent of the hydraulic control section 4 in the measuring apparatus M of the illustrated embodiment.
In FIG. 7, a hydraulic pressure adjusting valve 2 similar to a check valve including a ball 18 as a valve body and a spring 19 for urging the ball 18
0 is provided, and the downstream side of the hydraulic pressure control valve 20 is connected to the oil pan 5 of the internal combustion engine E via the throttle 21 and the outflow passage 12. Further, in this embodiment, a signal output from the sensor 15 of the measuring unit 3 is input to a measurement / control device (not shown).

Since the apparatus M for measuring the insoluble matter in the lubricating oil as the first embodiment is constructed in this way,
During operation of the internal combustion engine E that uses the lubricating oil to be measured, part of the lubricating oil is shunted from the oil line 1 of the internal combustion engine E, and the direction is given by the inflow passage 2 to measure the measuring chamber of the measuring unit 3. Then, it flows into 14 and cleans the detection end 22 of the sensor 15. This prevents dirt such as insoluble particles from adhering to the detection end 22.

At this time, the light emitted from the light emitting portion (not shown) in the sensor 15 into the prism provided at the detection end 22 is totally reflected on the bottom surface of the prism, and at that time, a part of the light is an evanescent wave. Incident on the lubricating oil,
The light is reflected by a relatively shallow layer of lubricating oil, is incident again from the bottom surface of the prism, and reaches the light receiving portion together with the totally reflected light. The light that has entered the lubricating oil is absorbed and attenuated by an amount corresponding to the amount of insoluble particles, and then returns from the bottom surface of the prism back into the prism, so the amount of reflected light detected by the light receiving unit, The concentration of the insoluble matter is calculated by the measurement / control device from the amount of light emitted from the light emitting unit.

However, the lubricating oil circulating inside the internal combustion engine E usually contains a large amount of air bubbles due to stirring due to rotation of the crankshaft or the like, and the returning oil dropping into the oil pan 5 in drops. Therefore, under atmospheric pressure, the lubricating oil appears cloudy due to bubbles. Therefore, the lubricating oil in the measurement chamber 14 also contains some air bubbles, and the air bubbles reflect or scatter the light incident from the sensor 15. Therefore, unless some measures are taken, a large error will occur in the measurement result of the sensor 15. Will be entered.

In the first embodiment, the hydraulic pressure control section 4 is connected to the outlet section 17 of the measuring chamber 14, and the hydraulic pressure control section 4 includes a hydraulic pressure control valve 2 including a ball 18 and a spring 19.
0 is provided. In addition, the hydraulic control unit 4 of this embodiment is also provided with a fixed throttle 21 downstream of the hydraulic pressure adjusting valve 20. Therefore, when the lubricating oil pressure of the oil line 1 in the internal combustion engine E is extremely low, the ball 18 of the oil pressure adjusting valve 20 communicates with the outlet portion 17 of the measuring chamber 14 by the urging force of the spring 19, as shown in FIG. The valve seat 23 is closed, and the lubricating oil in the measurement chamber 14 is substantially stagnant. However, since the oil pressure adjusting valve 20 is closed, the lubricating oil in the measuring chamber 14 receives the oil pressure of the oil line 1 although it is low, and the pressure causes the bubbles to be compressed. Is relatively unlikely to cause an error due to the light reflected by the bubbles.

When the oil pressure in the oil line 1 rises a little, the pressure at the outlet 17 of the measuring chamber 14 exceeds the urging force of the spring 19 of the oil pressure adjusting valve 20, so as shown in FIG. 3 (b). The ball 18 of the hydraulic pressure control valve 20 separates from the valve seat 23 and opens. As a result, the lubricating oil in the measuring chamber 14 flows, enters the outflow passage 12 via the hydraulic pressure control unit 4, and returns to the oil pan 5 of the internal combustion engine E, so that the lubricating oil in the measuring chamber 14 is replaced with new one. At this time, the hydraulic pressure control valve 2
Since 0 itself has a throttling effect and a fixed throttle 21 is provided on the downstream side, the lubricating oil pressure in the measuring chamber 14 is lower than the oil pressure in the oil line 1, but has a substantially constant value. The bubbles contained in the lubricating oil are crushed and are hardly detected by the sensor 15.
As a result, the measurement / control device (not shown) that receives the signal from the sensor 15 can accurately calculate the concentration of the insoluble matter.

When the oil pressure of the lubricating oil in the oil line 1 further rises to a high pressure, the rotational speed of the internal combustion engine E rises and the load also increases.
As the lubricating oil pressure in the inside of the measuring chamber 14 increases, the opening degree of the oil pressure adjusting valve 20 further increases.
It does not rise much more than in the case of (b), and is maintained at about the same level. Therefore, also in this case, the measurement room 1
The bubbles contained in the lubricating oil in 4 are crushed and hardly detected by the sensor 15, and because the measurement is performed in the measurement chamber 14 under a substantially constant pressure, the difference in pressure causes Since it is not necessary to consider the fluctuation of the measurement result, the measurement accuracy of the measuring device M is maintained in a high state.

As described above, it is clear from the comparison between FIG. 4 and FIG. 5 that the influence of the bubbles is reduced by applying the pressure to the lubricating oil in the measuring chamber 14 of the measuring unit 3 by providing the hydraulic control unit 4. is there. That is, FIG. 4 is a diagram showing the bubble mixing ratio k (percentage of the total volume of bubbles in the lubricating oil) measured with the measurement chamber 14 opened to the atmospheric pressure, and FIG.
FIG. 4 is a diagram showing a bubble mixing ratio k measured in a state where the measurement chamber 14 is pressurized to 350 kPa which is an average oil pressure of an oil line in a normal internal combustion engine. As shown in FIG. 4, when the measurement chamber 14 is not pressurized and is at atmospheric pressure,
The value of the bubble inclusion rate k increases remarkably as the rotational speed increases.

Even at the same atmospheric pressure, the temperature of the lubricating oil is 120
In the case of ° C, the value of the bubble inclusion rate k becomes considerably higher than that in the case of 40 ° C, so it is understood that the value of k also changes depending on the temperature, but the measurement chamber 14 is pressurized to 350 kPa. While the value of k changes relatively little and the lubricating oil temperature is high at 120 ° C, the maximum speed of 6
The value of k at 000 rpm does not exceed 7.2%. From this fact, the effect of placing the measurement chamber 14 in a pressurized state is clear. Further, since the oil pressure in the measuring chamber 14 can be maintained substantially constant by the oil pressure adjusting valve 20, it is possible to obtain higher measurement accuracy because it is not affected by the pressure fluctuation.

FIG. 6 shows a main part of the second embodiment of the present invention. In the measuring device M ′ of the insoluble matter in the lubricating oil in this embodiment, the oil temperature control unit 24 is provided around the inflow passage 2.
Is provided. The oil temperature control unit 24 is, for example, a constant temperature heating heater that raises the temperature of the lubricating oil to a predetermined height. As the constant temperature heating heater, a heating wire or a ceramic heater that generates heat by energization should be used. You can In addition, a thermostat (not shown) is provided to control the amount of electricity, and a temperature sensor (not shown) for detecting the temperature of the heated lubricating oil is provided in the measurement chamber 14 or the like downstream of the oil temperature controller 24 in some cases. It is also possible to control the amount of electricity supplied to the oil temperature control unit 24 and adjust the amount of heat generation by a measuring / controlling device (not shown) that operates according to the detected temperature. The oil temperature control unit 24 is not limited to one that heats the lubricating oil, but may be one that lowers the temperature of the lubricating oil to a certain low temperature by cooling the lubricating oil using a Peltier element or the like.

When measuring the concentration of the insoluble matter in the lubricating oil in the measuring chamber 14, it is clear from the above that the bubble mixing rate is a function of the oil temperature as well as the hydraulic pressure and the engine speed. However, in the second embodiment, the measurement conditions are kept constant by controlling the temperature of the lubricating oil flowing into the measuring chamber 14, or the lubricating oil flowing into the measuring chamber 14 is cooled to a constant temperature. By doing so, the measurement conditions are kept constant and the bubble inclusion ratio k is lowered, and in any case, the measurement accuracy is improved. The other points are similar to those of the first embodiment described above.

In the first and second embodiments, a check valve type hydraulic pressure adjusting valve 20 and a fixed throttle 21 are used as the hydraulic pressure control section 4. This hydraulic pressure regulating valve 20 is used in the measurement chamber 1
Although the hydraulic pressure itself in the measurement chamber 14 is automatically increased / decreased by opening / closing according to the hydraulic pressure of the lubricating oil in the hydraulic pressure control valve 4, the hydraulic pressure control valve 20 which is driven dynamically is used in the present invention. In addition to the above, it is also possible to use a hydraulic pressure control valve that positively maintains the hydraulic pressure in the measuring chamber 14 at a high pressure of a constant value in the hydraulic control unit 4.

For example, a hydraulic pressure sensor (not shown) for detecting the lubricating oil pressure in the measuring chamber 14 so as to prevent the lubricating oil pressure in the measuring chamber 14 from changing when the operating state of the internal combustion engine E changes. At the same time, an electromagnetic valve as a hydraulic pressure adjusting valve, which is controlled to open and close by a measurement and control device (not shown) that operates in response to a signal from the hydraulic pressure sensor in the measuring chamber 14, is provided to keep the lubricating hydraulic pressure in the measuring chamber 14 constant. The solenoid valve is opened and closed to maintain the height of. As a result, it is possible to suppress the bubble inclusion rate of the lubricating oil in the measurement chamber 14 to a low level, so that it is possible to reliably prevent an error due to bubbles from being included in the detection value of the sensor 15.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a first embodiment of the present invention.

FIG. 2 is an overall configuration diagram showing a connection relationship between an internal combustion engine operated by a lubricating oil which is a measurement target of the device of the present invention and the device of the present invention.

3 (a) to 3 (c) are enlarged cross-sectional views showing different operating states of the main part of the first embodiment.

FIG. 4 is a diagram showing a change in a bubble mixing ratio in lubricating oil under atmospheric pressure, depending on engine speed and oil temperature.

FIG. 5 is a diagram showing a change in a bubble mixing ratio in lubricating oil in a pressurized state according to engine speed and oil temperature.

FIG. 6 is a cross-sectional view showing the main parts of the second embodiment.

[Explanation of symbols]

 E ... Internal combustion engine M ... Measuring device of the first embodiment M '... Measuring device of the second embodiment 1 ... Oil line 2 ... Inflow passage 3 ... Measuring part 4 ... Hydraulic control part 5 ... Oil pan 7 ... Oil pump 14 ... Measuring chamber 15 ... Sensor 20 ... Hydraulic pressure regulating valve 21 ... Fixed throttle 22 ... Sensor detection end 24 ... Oil temperature control unit

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yoshimasa Kodama 14 Iwatani, Shimohakaku-cho, Nishio-shi, Aichi Japan Auto Parts Research Institute, Inc. (72) Inventor Moritsui Mitsuji 14 Iwatani, Shimohakaku-cho, Nishio-shi Japan Auto Parts Research Institute, Inc. (72) Inventor Toru Yoshinaga 14 Iwatani, Shimohakaku-cho, Nishio-shi, Aichi Prefecture Japan Auto Parts Research Institute, Inc. (72) Inventor O-saki ▼ Showa-cho, Kariya Aichi Prefecture 1-chome 1 Nihon Denso Co., Ltd.

Claims (6)

[Claims] 1. An inflow passage for taking out pressurized lubricating oil from an oil line of an internal combustion engine, and a sensor connected to a downstream side of the inflow passage for detecting the concentration of an insoluble component in the lubricating oil by light. A measurement chamber that is connected to the downstream side of the measurement chamber, and a hydraulic pressure control unit that controls the pressure of the lubricating oil in the measurement chamber; A device for measuring insoluble matter in lubricating oil, which comprises an outflow passage for sending back, and the hydraulic pressure control unit controls the pressure of the lubricating oil in the measuring chamber in a direction to have a constant value as high as possible. . 2. The insoluble matter measuring device in lubricating oil according to claim 1, wherein the hydraulic pressure control section is composed of a hydraulic pressure adjusting valve. 3. The insoluble matter measuring device for lubricating oil according to claim 2, wherein the hydraulic pressure control section is provided with a hydraulic pressure regulating valve and a fixed throttle together. 4. The ball-shaped valve body, wherein the hydraulic pressure regulating valve comprises:
The insoluble matter measuring device in lubricating oil according to claim 2 or 3, characterized in that the device comprises a spring for urging the spring toward the valve seat. 5. The lubricating oil according to claim 1, wherein the hydraulic pressure adjusting valve is an electromagnetic valve that is opened / closed so that the lubricating hydraulic pressure in the measurement chamber becomes constant. Insoluble matter measuring device. 6. The apparatus for measuring insoluble matter in lubricating oil according to claim 1, wherein the inflow passage is provided with an oil temperature control section.