JPH1082735A - Device for measuring insoluble matter in lubrication oil - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce measurement errors due to bubbles contained in a lubrication oil in an optical density measuring device for insoluble particles in a lubrication oil such as an engine oil. SOLUTION: The measurement device M includes and an optical measurement unit 3 connected to an inflow path 2 for taking out a lubrication oil from an oil line 1 of an internal combustion engine E, and the measurement chamber irradiates an inflowing lubrication oil with light so as to generate reflection, absorption, diffusion, penetration, and the like, thereby measuring the density of insoluble particles contained in a lubrication oil. In order to remove bubbles contained in a lubrication oil in the measurement chamber, a cyclone type bubble separator 5 set on the upstream side. A throttle is provided on the upstream side from the bubble separator 5 and a pump 59 is provided on the downstream side therefrom, and in a gaseous phase part where separated bubbles stay is subjected to an exhaust operation by a vacuum pump 46. An oil temperature controller 4 maintains the temperature of oil constant. A check valve 26 serves to maintain the hydraulic pressure constant, and both of them are useful to improve the measurement accuracy.

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 an optical density measurement device 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.

[0003] For such a reason, Japanese Patent Application Laid-Open No. 7-72072 discloses one device 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 part toward the bottom of the prism at the angle of incidence that is totally reflected, not all of the irradiated light is actually reflected at the bottom of the prism, and part of the irradiated light is actually reflected on the bottom of the prism. And enters the oil as an evanescent wave, is reflected by a relatively shallow layer, returns to the prism again, and reaches the light receiving section together with the total reflected light. At that time, the evanescent wave incident on the oil hits the insoluble particles in the oil and is absorbed or scattered and attenuated.As a result, the amount of light reaching the light receiving unit is reduced by the light emitted from the light emitting unit. Since the amount is smaller than the amount, the concentration of the insoluble portion in the oil is calculated from the degree of the decrease. 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.

[0004]

All of these devices for measuring the insoluble content contained in engine oil are attached to an automobile engine and have a predetermined concentration such that the concentration of the suit contained in the engine oil is, for example, 3%. When it reaches the value of, it is developed as a warning device to turn on the warning light to notify the driver that the time for oil change has come, so it does not require particularly high measurement accuracy. is there. For this reason, it is possible to roughly understand the timing of the target oil change, but the accuracy of the measurement result cannot be said to be high, and the concentration of the suit and the like in the lubricating oil (engine oil) is accurately measured. Not suitable for use as a measuring instrument.

The lubricating oil circulating while repeatedly pressurizing the interior of the engine with a lubricating oil pump and depressurizing by injection into the air at the lubricated portion includes:
Although some bubbles are mixed as a normal state, when the lubricating oil containing bubbles becomes a sample in an optical measuring device, for example, in a light reflection type insoluble matter measuring device using a prism, as an evanescent wave Since air bubbles reflect or absorb a relatively small amount of light incident on the lubricating oil, and are scattered or attenuated, the concentration of insoluble components in the lubricating oil cannot be accurately measured.

Further, the volume of the air bubbles mixed in the lubricating oil changes depending on the oil temperature of the lubricating oil, the oil pressure, the temperature of the glass surface such as the bottom surface of the prism contacting the lubricating oil, etc. Weight%) is the same, the ratio of the volume of bubbles in the lubricating oil, that is, the volume ratio changes with changes in oil temperature or oil pressure. Is generated. When the measurement is performed under a low pressure of about the atmospheric pressure, bubbles in the lubricating oil pressurized inside the engine greatly expand, so that the influence of the bubbles is particularly remarkable. In order to reduce the effect of the change in oil pressure, measurement is performed while lubricating oil is being pressurized, but pressurizing the lubricating oil does not completely eliminate bubbles contained in it. In addition, detection errors of different degrees occur depending on the amount of air bubbles mixed in and the oil pressure, and the process for correcting data becomes complicated.

The present invention addresses such a problem in the prior art and provides an optical concentration measuring device for particles insoluble in a lubricating oil such as an engine oil. It is an object of the present invention to provide an improved device for measuring the insoluble content in lubricating oil, which can sufficiently reduce the error due to the bubbles and improve the measurement accuracy of the concentration of the insoluble content. I have.

[0008]

According to the present invention, there is provided, as a means for solving the above-mentioned problems, an apparatus for optically measuring the concentration of insoluble components in lubricating oil as described in the claims. I will provide a.

According to the present invention, in any of the optical density measuring devices described in the claims, the pressurized lubricating oil taken out from the oil line of the internal combustion engine is measured by the inflow passage. Into the measuring chamber of the instrument. The measurement of the concentration of insoluble matter particles in the lubricating oil is performed by detecting the intensity of light that is incident on the lubricating oil and is reflected or transmitted by a sensor using light provided in the measurement chamber. Will be A common feature of the present invention is that a gas-liquid separator is provided upstream of the optical sensor,
Since the gas-liquid separator removes air bubbles in advance from the lubricating oil flowing into the measurement chamber, it is necessary to prevent the air bubbles from reflecting, scattering, or absorbing light in the measurement chamber, thereby reducing measurement accuracy. Can be prevented.

According to the second aspect of the present invention, the gas-liquid separator is of a cyclone type, and the gas-liquid separator is throttled upstream of the cyclone chamber and downstream of the cyclone chamber. And a vacuum pump communicating with the gas phase portion of the cyclone chamber. Since the pressure in the cyclone chamber is reduced by suction of lubricating oil by a pump with a throttle placed on the upstream side, when lubricating oil flows tangentially into the cyclone chamber,
Bubbles contained in the lubricating oil expand and the difference in specific gravity between the lubricating oil and the liquid phase increases, and is easily separated into a gas phase and a liquid phase by a swirling flow in the cyclone chamber. Since the phase portion is efficiently discharged by the vacuum pump, the gas-liquid separator has a high air bubble removing effect. As a result, the measurement accuracy of the measuring instrument is further improved.

According to the third aspect of the invention, for example, an oil temperature control means which can perform cooling and, if necessary, heating of the lubricating oil is provided upstream of the measuring instrument. The oil temperature of the lubricating oil flowing into the measuring chamber is adjusted to a substantially constant, as low as possible. Therefore,
Even if bubbles slightly remain in the lubricating oil, the expansion can be suppressed. Further, since the oil temperature is constant, the refractive index of light at the interface between the lubricating oil and the glass such as a prism also becomes constant. As a result, the effect of the oil temperature on the measurement accuracy can be reduced.

According to the fourth aspect of the present invention, since the hydraulic control means such as a check valve which opens at a constant hydraulic pressure is provided downstream of the measuring instrument, the measuring chamber is operated by the hydraulic control means. Is adjusted so that the oil pressure of the lubricating oil flowing into the tank becomes substantially a predetermined height. Therefore, even if the lubricating oil flowing into the measurement chamber contains air bubbles, the air bubbles are compressed and have a relatively small volume, and as a result, the influence of the oil pressure on the measurement accuracy can be reduced. it can.

According to the fifth aspect of the present invention, the optical sensor can be a light reflection type having a prism. In this case, the optical sensor is moved from the bottom surface of the prism to the lubricating oil in contact with the prism. The light that is incident as an evanescent wave is absorbed or scattered by the insoluble particles and attenuated, so that the amount of light that is totally reflected at the bottom of the prism is reduced. Measure the concentration of particles in the minute. In this case as well, the influence of bubbles contained in the lubricating oil is removed as described above, so that high measurement accuracy can be obtained.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The structure of a preferred embodiment of the present invention will be described with reference to FIGS. The measuring device (system) M for the insoluble content in the lubricating oil as an embodiment of the present invention is:
It is attached to a lubricating oil circuit of the internal combustion engine E as shown in FIG. That is, the measuring device M includes an inflow passage 2 branched from an oil line 1 through which pressurized lubricating oil of the internal combustion engine E flows, a measuring device 3 whose internal configuration will be described in detail later, and a flow of lubricating oil. The present invention comprises an oil temperature controller 4 as oil temperature control means provided upstream of the measuring device 3 and a gas-liquid separator 5 which is a feature of the present invention. Although not shown in the drawings, in order to perform necessary calculations based on the detection signals output from the optical sensors provided in the measuring device 3 and other control operations, for example, an electronic system including a microprocessor may be used. Measurement and control devices are provided as needed.

In the internal combustion engine E which is operated using the lubricating oil to be measured by the measuring device M of the embodiment, the oil is pumped up from the oil pan 6 by the oil pump 7 via a strainer or the like to a predetermined oil pressure. The pressurized lubricating oil is supplied to a common oil line 1 for a number of lubricated points through a lubricating oil filter (not shown), and distributed to a number of branched lubricating oil passages 8 branched from the oil line 1. Thereafter, the lubricating oil is supplied to the periphery of the piston 9, the camshafts 10, 11, and bearings such as bearings by the branched lubricating oil passages 8. The measuring device M in the embodiment takes out a part of the pressurized lubricating oil circulating inside the internal combustion engine E from the common oil line 1 and measures the concentration of the insoluble component contained therein. The measurement is performed by the measuring device 3. After the measurement is completed, the lubricating oil returns to the oil pan 6 through the outflow passage 12.

As shown in FIGS. 2 and 3, the measuring device 3 in the measuring device M according to the embodiment of the present invention includes an inflow passage branched from the oil line 1 of the internal combustion engine E in a casing 13. 2 is a measuring chamber 14 for receiving the lubricating oil through the gas-liquid separator 5 and the oil temperature controller 4 to measure the concentration of insoluble components, and an optical sensor 15 provided facing the measuring chamber 14. Have. The detection end 15a of the optical sensor 15 projects into the measurement chamber
Contact with lubricating oil filled inside. The measuring chamber 14 has an inlet 16 for receiving the lubricating oil from the oil temperature controller 4 therein, and an outlet 17 for returning the measured lubricating oil to the oil pan 6 of the internal combustion engine E through the outflow passage 12. Is open.

The sensor 15 in the illustrated embodiment is of an optical type, particularly of a light reflection type. In this case, the sensor 15 is used in the liquid particle concentration detecting device described in the above-mentioned Japanese Patent Application Laid-Open No. 7-72072. A prism having a prism 18 having a pentagonal cross section is used. Further, an inlet 16 connected to the inflow passage 2 on the downstream side of the oil temperature controller 4.
Is generally the detection end 15a of the sensor 15, that is, the prism 18
The pressurized lubricating oil supplied from the oil line 1 is opened to the measurement chamber 14 toward the bottom of the inflow passage 2.
When it passes through the inlet 16 and flows out of the inlet 16 into the measurement chamber 14, it becomes a jet and cleans the detection end 15 a, thereby preventing insoluble particles from adhering to the bottom surface of the prism 18.

This operation is achieved by enclosing some cleaning balls 19 in the measurement chamber 14 in advance. If the cleaning balls 19 collide with the bottom surface of the prism 18 due to the flow of the lubricating oil, the undissolved component Of particles and the like can be more effectively prevented from adhering to particles and the like insoluble portions than in the case of cleaning only by the flow of lubricating oil. As the cleaning ball 19, a ball made of a synthetic resin whose hardness is lower than the hardness of the glass material of the prism 18 is used. In addition, a wire mesh or the like for preventing the escape of the cleaning ball 19 is provided at the entrance 16 and the exit 17.

Since the present invention has no characteristic in the measuring device 3 or the sensor 15 itself, the structure of the light reflection type measuring device 3 illustrated in FIG. 2 will be described only briefly. In the figure, a light emitting unit 20 having a light emitting diode and a reflected light receiving unit 21 having a photodiode are provided on the left and right symmetric inclined surfaces above a prism 18 having a pentagonal cross section. Is brought into contact with the lubricating oil (engine oil) in the measuring chamber 14 from the light-emitting portion 20 toward the bottom surface of the prism 18 at the incident angle where the light is totally reflected in a normal sense on the bottom surface of the prism 18 serving as the detection end 15a. To emit light. Part of the light is split by the beam splitter 22 provided in front of the prism 18 and directly enters the incident light receiving unit 23 having a photodiode without passing through the prism 18. The photodiodes of the light receiving section 21 and the incident light receiving section 23 are connected to lead wires 24 and 2 respectively.
5 connects to an electronic measurement and control device (not shown).

The pressurized lubricating oil flowing into the measuring chamber 14 from the inlet 16 fills the measuring chamber 14 and then flows out of the outlet 17.
Through the outflow passage 12 to the oil pan 6 of the internal combustion engine E, and a check valve 26 is provided on the way. The check valve 26 in the illustrated example is composed of a spherical valve body 27 and a spring 29 for urging the valve body 27 toward an upstream valve seat 28. To maintain the oil pressure at a predetermined height.

In the illustrated embodiment, an oil temperature controller 4 for adjusting the oil temperature of the lubricating oil in the measurement chamber 14 as a subject to a relatively low constant value is provided in order to increase the measurement accuracy. As shown in FIG. 3, the oil temperature controller 4 includes a cooling water jacket 30 surrounding a part of the inflow passage 2 connected to the inlet 16 of the measuring device 3 to form a heat exchanger, and a cooling water jacket thereof. A cooling water inlet pipe 31 for supplying cooling water to the cooling water pipe 30; an electromagnetic valve 32 provided in a part thereof; a cooling water discharge pipe 33 for discharging cooling water from the cooling water jacket 30; , An oil temperature sensor 35 such as a thermocouple provided near the inlet 16 of the measuring instrument 3, and the electromagnetic valve 32 is opened and closed according to a temperature signal detected by the oil temperature sensor 35. And an oil temperature controller 36 that can heat the cooling water in the cooling water jacket 30 by energizing the electric heater 34 in some cases. Accordingly, the oil temperature controller 36 adjusts the temperature and flow rate of the cooling water to maintain the oil temperature of the lubricating oil flowing into the measurement chamber 14 at a relatively low constant value, and the bubbles contained in the lubricating oil expand. And increase measurement accuracy.

Next, the configuration of the gas-liquid separator 5 which can be said to be the largest feature of the insoluble matter measuring apparatus M as an embodiment of the present invention will be described with reference to FIG. The gas-liquid separator 5 shown in FIG. 4 has a cylindrical upper housing 37 and a lower housing 38, each of which has a cyclone chamber 3 therein.
7a and a space called a baffle chamber 38a. These spaces are vertically divided by a partition wall 39, and a communication hole 40 is opened at the center of the partition wall 39, so that the spaces communicate with each other through the communication hole 40. In addition, on the lower surface of the partition wall 39, an inclined surface 39a that is upward from the outer periphery toward the center flow hole 40 is formed so as to form a conical shape. The above-described inflow passage 2 branched from the oil line 1 of the internal combustion engine E is tangentially connected to the wall surface of the cyclone chamber 37a, that is, a part of the cylindrical surface of the upper housing 37. An opening 41 is formed. Then, a throttle 4 is formed in the inflow passage 2 on the upstream side of the opening 41.
2 are formed.

A deaeration passage 45 is connected to a central opening 44 of the top wall 43 of the upper housing 37 and communicates with a suction port of a vacuum pump, which is schematically shown as 46. An oil level sensor 47 having a float is provided at a position at a predetermined height at the center in the cyclone chamber 37a, and the oil level in the cyclone chamber 37a is lowered to the position of the oil level sensor 47. When the vacuum pump 46 detects the output signal of the oil level sensor 47,
Is closed, and the vacuum pump 46 starts rotating. Reference numeral 48 denotes a power supply of the vacuum pump 46.

In the baffle chamber 38a, upper and lower cylindrical walls 49 and 50 are connected to each other, and a horizontal partition wall 51 for vertically dividing the internal space of the baffle chamber 38a. Similarly, it is divided into three parts: a lower lower chamber 53 and an outer chamber 54 inside the lower housing 38 outside the upper and lower cylindrical walls 49 and 50. The upper surface of the horizontal partition wall 51 is flat, but the lower surface is formed with an inclined surface 51a that rises from the center toward the outer periphery.
In the upper part of the cylindrical wall 49, a plurality of circular outflow holes 55 are opened in this case, and in the upper part of the cylindrical wall 50, a plurality of rectangular inflow holes 56 are opened. A flow path 58 connecting the lower chamber 53 to the outside is provided on the bottom wall shown as 57.
A pump 59 that sucks lubricating oil from inside the gas-liquid separator 5 is provided in the middle of a flow path 58 that forms a part of the inflow passage 2 on the downstream side of the gas-liquid separator 5. ing. Reference numeral 60 denotes a mounting leg of the gas-liquid separator 5.

The apparatus M for measuring the amount of insoluble matter in the lubricating oil according to the embodiment of the present invention is configured as described above, and therefore, during operation of the internal combustion engine E using the lubricating oil to be measured. 3, a part of the lubricating oil is diverted from the oil line 1 of the internal combustion engine E, and given a direction by the nozzle-shaped inlet portion 16 of the inflow passage 2 as shown in FIG. When it flows in as a jet, the bottom surface of the prism 18 which is the detection end 15a of the sensor 15 shown in FIG. 2 is washed. Since the cleaning ball 19 is floating in the lubricating oil in the measurement chamber 14, the cleaning ball 19
Collides with the bottom surface of the prism 18 to enhance its cleaning action. Therefore, it is possible to prevent the detection end 15a from fogging due to adhesion of dirt such as insoluble particles. The lubricating oil in the measurement chamber 14 flows from the outlet 17 to the outflow passage 1
2 and returns to the oil line 1 of the internal combustion engine E again, so that the lubricating oil in the measuring chamber 14 is constantly forcibly circulating and flowing, and the measuring device M thus circulates in the internal combustion engine E. Lubricating oil can be inspected evenly.

When the measurement is performed, light emitted from the light emitting section 20 in the sensor 15 into the prism 18 is applied to the prism 1.
8 is actually reflected by the bottom surface of the prism 8, but in fact, a part of the light enters as an evanescent wave so as to penetrate into the lubricating oil in the measuring chamber 14, is reflected by a relatively shallow layer of the lubricating oil, and is again reflected by the prism. When the light enters the prism from the bottom surface, the light reaches the light receiving unit together with the light that has been totally reflected.
At this time, the light that has entered the lubricating oil as an evanescent wave is absorbed or scattered by an amount corresponding to the amount of insoluble particles, attenuates, and then returns to the prism from the bottom surface of the prism 18 again. The ratio of the amount of light emitted from the light emitting unit 20 estimated from the amount of light detected by the incident light receiving unit 23 to the amount of reflected light detected by the reflected light receiving unit 21 is the concentration of the insoluble portion. The amount insoluble is calculated by the measurement / control device from the relationship of being proportional to.

However, if the lubricating oil contains air bubbles as described above, the air bubbles scatter or absorb the light, so that the reflected light detected by the reflected light receiving portion 21 of the sensor 15 is reflected. Varies depending on the content of bubbles in the lubricating oil (% by weight) and the volume ratio of the bubbles (volume%), which varies depending on the oil temperature and oil pressure of the lubricating oil. All of which will cause errors in the measurement results. In order to deal with these problems, in the embodiment of the present invention shown in FIG. 1, a gas-liquid separator 5 and an oil temperature controller 4 are connected in series on the upstream side of the lubricating oil inflow passage 2 to the measuring device 3. Provided.

The specific operation of the oil temperature controller 4 will be described first. The oil temperature controller 4 controls the oil temperature of the lubricating oil flowing into the measuring chamber 14 of the measuring device 3 from the inflow passage 2 (in the illustrated embodiment, a downstream flow path (not shown) of the pump 59 connected to the gas-liquid separator 5). To a constant value as low as possible,
As shown in FIG. 3, the lubricating oil passing through the inflow passage 2 and flowing into the measuring device 3 is used to prevent an error in the measurement result due to the difference in the oil temperature. Cooling is performed by the cooling water flowing through the cooling water jacket 30 in the temperature controller 4. The degree of cooling increases or decreases the flow rate of the cooling water flowing through the cooling water jacket 30 by an electromagnetic valve 32 whose opening is controlled by an oil temperature controller 36 in accordance with the oil temperature measured by the oil temperature sensor 35. It is adjusted by doing. When the oil temperature is abnormally low, such as during warm-up, the oil temperature controller 36 energizes the electric heater 34 to a necessary degree to heat the cooling water. By the oil temperature controller 36 performing such control, the oil temperature of the lubricating oil flowing into the measuring chamber 14 of the measuring device 3 becomes a predetermined value.

In the illustrated embodiment, by maintaining the oil pressure of the lubricating oil in the measuring chamber 14 at a constant level, the lubricating oil contained in the lubricating oil in the measuring chamber 14 even after passing through the gas-liquid separator 5. The volume ratio of a small amount of air bubbles is kept constant to eliminate measurement errors in the measuring device 3 due to air bubbles. That is, in this example, the check valve 26 is provided downstream of the measuring device 3. When the oil pressure in the measuring chamber 14 exceeds a predetermined value, the valve body 27 of the check valve 26 resists the urging force of the spring 29. Away from the valve seat 28 and the outlet 17 of the measuring chamber 14
Is communicated to the outflow passage 12, so that the lubricating oil pressure in the measurement chamber 14 is always maintained at a constant level, and a measurement error caused by a change in the volume ratio of bubbles due to a change in oil pressure is eliminated.

As described above, when the oil pressure of the lubricating oil in the measuring chamber 14 of the measuring device 3 is maintained at a constant value by the hydraulic control means such as the check valve 26, the constant pressure value is higher. Is good. The reason is that the higher the oil pressure is, the more the bubbles are compressed and reduced, resulting in a smaller volume ratio of the bubbles. Under various operating conditions of the internal combustion engine E in which the number of revolutions changes, the result of actually measuring the change in the volume ratio of bubbles when the oil pressure in the measurement chamber 14 is set to the atmospheric pressure without the check valve 26 is shown in FIG. Shown in As can be seen from FIG. 5, when the rotational speed of the internal combustion engine E increases, the volume of air bubbles increases, so that the volume ratio thereof significantly increases.

On the other hand, the lubricating oil pressure of the measuring chamber 14 is set to 3
FIG. 6 shows the result of measuring the volume ratio of bubbles when the pressure was maintained at 50 KPa. The rotation speed of the internal combustion engine E is 1000 rpm
Even if it changes drastically from m to 6000 rpm, the increase in the volume ratio of bubbles is only small. As is clear from the comparison between the two experimental results shown in FIGS. 5 and 6, even when the content of bubbles is actually increasing, increasing the oil pressure in the measurement chamber 14 slightly increases the volume ratio of bubbles. From this viewpoint, in order to maintain the measurement accuracy of the measuring device 3 high, the check valve 2 is required.
It is effective to maintain the hydraulic pressure in the measurement chamber 14 at a constant relatively high value by means such as 6.

Next, the operation of the gas-liquid separator 5 installed on the upstream side of the measuring device 3 and the oil temperature controller 4 will be schematically described with reference to FIG. 7 and FIG. 8 schematically showing the operation of the comparative example. In addition to the oil pressure of the oil line 1 of the internal combustion engine E, the pump 59 provided on the downstream side of the gas-liquid separator 5 is driven, so that the entirety of the inside of the gas-liquid separator 5 is located on the downstream side of the throttle 42. Since the suction action occurs, the lubricating oil flowing tangentially into the cyclone chamber 37a from the inflow passage 2 through the opening 41 into the cyclone chamber 37a has a strong lubricating oil along the inner wall surface of the upper housing 37 as shown in FIG. This produces a swirling flow. Opening 41
Is provided upstream of the throttle 42, the hydraulic pressure on the downstream side of the throttle 42 is reduced, so that the bubbles contained in the inflowing lubricating oil expand and collectively grow,
The difference in specific gravity between the lubricating oil and the liquid phase increases. Due to the difference in centrifugal force generated by the rotation, a liquid phase portion R having a large specific gravity is formed separately near the lower outer periphery, and a gas phase portion G having a small specific gravity is formed in a trumpet shape near the upper center. You.

The swirling flow of the liquid phase portion R flows through the flow holes 4 of the partition wall 39.
0, the spillover reaches the upper chamber 52 in the lower housing 38, and the lower end of the gas phase portion G becomes a thin rod and reaches the upper surface of the horizontal partition wall 51. When the lubricating oil in the liquid phase portion R passes through the outflow hole 55 and flows radially to the outer chamber 54 in the lower housing 38, the swirling flow of the lubricating oil is considerably attenuated. And
Also, when flowing in the radial direction from the outer chamber 54 to the lower chamber 53 formed at the lower part of the partition wall 51 through the inflow hole 56,
The swirling flow will be further attenuated. During this time, the lower room 5
The minute bubbles slightly remaining in the lubricating oil in 3 also aggregate and rise due to the difference in specific gravity with the lubricating oil, and return from the lower chamber 53 to the outer chamber 54 along the lower inclined surface 51 a of the partition wall 51. Also, the slight bubbles in the outer chamber 54 also aggregate and rise due to the difference in specific gravity with the lubricating oil, pass through the outflow hole 55 inward in the radial direction, and are formed on the lower surface of the partition wall 39 toward the center flow hole 40. After rising along the inclined surface 39a, the flow holes 40
To the cyclone chamber 37a and merges with the gas phase portion G.

As described above, the lubricating oil from which almost all the bubbles have been removed by passing through the gas-liquid separator 5 is a part of the inflow passage 2 (a downstream portion of the gas-liquid separator 5). 5
In the case of the illustrated embodiment, the oil flows into the oil temperature controller 4 through the pump 8 and the pump 59, is adjusted to a constant oil temperature and is supplied to the measuring device 3, and the concentration of the insoluble component is measured in the measuring chamber 14. Therefore, compared to the case where a large amount of bubbles are contained in the lubricating oil, the evanescent wave is not scattered or absorbed by the bubbles, so that the measurement accuracy can be improved in this plane.

By the operation of the gas-liquid separator 5, a trumpet-shaped gas phase portion G is continuously formed in the cyclone chamber 37 a and, in some cases, through the flow hole 40 of the partition wall 39 to the upper chamber 52 of the lower housing 38. Although formed, the bubbles contained in the lubricating oil are separated and the volume occupied by the gas phase portion G increases, and when the oil level of the liquid phase portion R drops to a predetermined level, the oil level floats. And the vacuum pump 46 is driven to suction the gas in the gas phase portion G and discharge the gas until the oil level reaches a predetermined height. Therefore, the operation of the gas-liquid separator 5 can be performed continuously for a long time without any trouble.

If the cause of the problem that air bubbles contained in the lubricating oil are one of the factors that affect the measurement accuracy in the measuring device 3 has already been determined, the upstream of the measuring device 3 Although the idea of providing a cyclone-type gas-liquid separator 61 having a normal structure as shown in FIG. 8 and removing bubbles in advance may be easily obtained, such a normal cyclone-type gas-liquid separator may be obtained. In the case where the gas phase 61 is used, since the lower end of the trumpet-shaped gas phase portion G formed in the cyclone chamber 61a is long and extends to the flow path 58, the bubble separation performance is low, and the gas bubbles not separated from the liquid phase portion R are low. Is likely to flow into the measuring device 3 on the downstream side. On the other hand, a partition wall 39 having a flow hole 40 as in the illustrated embodiment, an upper chamber 52, an outer chamber 54, and a lower chamber 53 that are radially communicated with each other in the lower housing 38 by an outflow hole 55 and an inflow hole 56 are provided. With the provision, the bubble separation performance is significantly improved, and the amount of bubbles flowing into the measuring device 3 is extremely small. The slightly remaining air bubbles are also reduced by the action of the oil temperature controller 4 and the check valve 26 as a hydraulic regulator,
Since the evanescent wave in the measuring chamber 14 is not scattered or absorbed, the measuring accuracy of the measuring device 3 is higher than that of the conventional measuring device.

[Brief description of the drawings]

FIG. 1 is a perspective view conceptually showing the overall configuration of a measuring device as an embodiment of the present invention, attached to an internal combustion engine.

FIG. 2 is a conceptual sectional view showing a configuration of a measuring instrument.

FIG. 3 is a cross-sectional view showing a configuration of an oil temperature controller and a partial configuration of a related measuring device.

FIG. 4 is a longitudinal sectional view illustrating the structure of the gas-liquid separator.

FIG. 5 is a diagram showing a change in the volume ratio of bubbles when the oil pressure in the measurement chamber is atmospheric pressure.

FIG. 6 is a diagram showing a change in the volume ratio of bubbles when the oil pressure in the measurement chamber is increased.

FIG. 7 is a schematic sectional view for explaining the operation of the gas-liquid separator shown in FIG.

FIG. 8 is a schematic cross-sectional view illustrating an operation when a normal gas-liquid separator is used.

[Explanation of symbols]

 E: Internal combustion engine M: Measuring device of the embodiment 1 ... Oil line 2 ... Inflow passage 3 ... Measuring device 4 ... Oil temperature controller 5 ... Gas-liquid separator 6 ... Oil pan 12 ... Outflow passage 14 ... Measuring chamber 15 ... Sensor Reference numeral 15a: Sensor detection end 18: Prism 19: Cleaning ball 20: Light emitting unit 21: Reflected light receiving unit 22: Beam splitter 23: Incident light receiving unit 26: Check valve 30: Cooling water jacket 32: Electromagnetic valve 34: Electric heater 35 ... oil temperature sensor 36 ... oil temperature controller 37 ... upper housing 37a ... cyclone chamber 38 ... lower housing 39 ... partition wall 40 ... flow hole 41 ... tangential opening 42 ... throttle 44 ... central opening 46 ... vacuum pump 47 ... Oil level sensors 49, 50 ... cylindrical wall 51 ... horizontal partition wall 51a ... inclined surface 52 ... upper chamber 53 ... lower chamber 54 ... outer chamber 55 ... outlet hole 56 ... flow Hole 59 ... pump 61 ... usually of cyclone type gas-liquid separator

Claims (5)

[Claims] 1. An inflow passage for extracting pressurized lubricating oil from an oil line of an internal combustion engine, a measurement chamber of a measuring instrument connected to the inflow passage, and a lubricating oil attached to the measurement chamber and flowing into the room. An optical sensor that detects the concentration of insolubles in the light using light, and an optical sensor provided upstream of the optical sensor to remove bubbles contained in the lubricating oil flowing into the measurement chamber. An optical concentration measuring device for insoluble particles in lubricating oil, comprising a gas-liquid separator. 2. The gas-liquid separator according to claim 1, wherein the gas-liquid separator is of a cyclone type, and a throttle is provided on an upstream side of the cyclone chamber, a pump sucks lubricating oil on a downstream side of the cyclone chamber, and a gas in the cyclone chamber is further provided. The optical density measuring apparatus according to claim 1, further comprising a vacuum pump communicating with the phase portion. 3. An oil temperature control means for adjusting an oil temperature of the lubricating oil flowing into the measuring chamber to a substantially predetermined value is provided. Optical density measurement device as described. 4. The apparatus according to claim 1, further comprising hydraulic pressure control means for adjusting the hydraulic pressure of the lubricating oil flowing into said measuring chamber to a substantially predetermined value. 4. The optical density measurement device according to 1. 5. The optical density measuring apparatus according to claim 1, wherein said optical sensor is of a light reflection type provided with a prism.