JPH01162152A - Measuring apparatus for degree of oil degradation - Google Patents

Abstract

PURPOSE:To measure the degree of degrading of oil accurately even when temperature of oil changes, by outputting a correction signal to a measuring sensor such as pollution degree measuring sensor or water content measuring sensor according to the temperature of the oil detected. CONSTITUTION:When an oil temperature measuring signal (T) from an oil temperature measuring sensor 25 is inputted into a pollution degree correction function calculating section 29 and a water content correction function calculating section 30 separately, the correction function calculating sections 29 and 30 generate correction signals respectively according to a pollution degree correction function f(T) and a water content correction function F(T). A pollution degree measuring sensor 27 and a water content measuring sensor 28 are connected to a pollution degree measuring section 31 and a water content measuring section 32 respectively and outputs of the pollution degree correction function calculating section 29 and the pollution degree measuring section 31 are inputted into a multiplying section 33 to multiply and outputs of the water content correction function calculating section 30 and the water content measuring section 32 into a multiplying section 34 to multiply. The resulting multiplied values are inputted into a decision section 35 to be compared with judging conditions previously inputted from a judging conditions setting section 36 and the results of the judgement are shown on a display section 37.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention (Field of Industrial Application) The present invention relates to an oil deterioration degree measuring device for monitoring and measuring the deterioration state of oil such as lubricating oil and hydraulic oil.

(Prior art) In general, deterioration and contamination of hydraulic oil, which is the working medium of control devices such as bearings of rotating equipment and reduction gears, and electric/hydraulic servo valves, is generally caused by system configuration. This can cause failure of equipment (e.g. bearings, reducers, oil pumps, electric/hydraulic servo valves). For this reason, in recent years, oil property management has been actively carried out, and devices for measuring the degree of deterioration of oil have also been proposed.

For example, as shown in FIG. 4, viscosity sensor 3 and moisture sensor 4 are arranged in hydraulic oil 2 in oil tank 1, and A device is disclosed that measures the deterioration of hydraulic fluid by inputting the measurement signal into a hydraulic fluid deterioration measuring device 5 that includes a measuring section 6, a determining section 7, a determining condition setting section 8, and a display section 9. .

Furthermore, FIG. 5 shows an example of an oil deterioration degree measuring device in which contamination degree and moisture content are selected as monitoring items. Flow rate controller 12, pollution level measurement sensor 1
3. A moisture content measurement sensor 14 is provided,
The measurement signals from the contamination degree measurement sensor 13 and the moisture measurement sensor 14 are input to the hydraulic fluid deterioration measuring device 5, which includes a determination section 7, a determination condition setting M8, and a display section 9, and the degree of deterioration and contamination is measured.

In addition, as another oil deterioration degree measuring device, the average lubricant temperature over a certain period of time is calculated, the degree of deterioration is calculated by corresponding to the deterioration curve of the lubricating oil against oil temperature and time, and this is integrated. (Japanese Unexamined Patent Publication No. 56-133658), which displays the degree of deterioration and replacement time, and evaluates the state of wear and tear based on a specific formula that also takes into account the temperature state of the lubricating oil during use. There are devices that determine lubricating oil deterioration by evaluating oil wear using a reasonable approximate value (Japanese Unexamined Patent Publication No. 58-213244), but these devices are based on actual measurement results. However, the judgment accuracy is low.

(Problems to be Solved by the Invention) The conventional oil deterioration degree measuring device described above reduces the burden on operators and prevents accidents by early detection of oil deterioration or abnormalities, compared to regular sample inspection by operators. Although it is very useful in these respects, there are some problems as follows.

The basic measurement principle of the pollution level measurement sensor 13 mentioned above is a light scattering method or a light blocking method, but in either method, the size of particles (contaminants) within a certain volume (v) and The degree of contamination is classified by measuring the number of particles. In other words, in a system that maintains a certain flow rate, the size and number of particles passing through the sensor within a certain period of time are measured. In addition,
- constant volume m is expressed as V=QXt. (Here, Q is the flow rate adjusted by the flow rate regulator 12, and t is the measurement time.) Also, the basic measurement MT of the moisture content measurement sensor 14! i
Most of the methods use Henry's law (the mass of gas dissolved in a certain amount of liquid at a certain temperature is proportional to the vapor pressure of the gas phase in equilibrium with it). The water content (C) of is expressed as C=(Cs/Ps)P. (Here, Cs is the saturated water concentration (PPM) at the measured hydraulic oil temperature, Ps is the saturated water vapor pressure, and P is the measured value of the water vapor pressure of the hydraulic oil being measured.) Figure 6 shows a certain hydraulic oil. This shows the relationship between the saturated water concentration and the saturated water vapor pressure, for example, at an oil temperature of 45°C.
The saturated water concentration (Cs) at (P point) is approximately 6200P
PM, and the saturated water vapor pressure (Ps) is 9.5×11
Note that these characteristics vary depending on the hydraulic oil, and each value is determined by experiment. On the other hand, if the hydraulic oil water vapor pressure (P) measured by the moisture content measurement sensor 14 is 1X1O-2ktr/d, then the moisture content (C) is C=(6200
/9.5 x 1O-2) x 1 x 10-2*
Calculated as 650PPM.

Now, what must be noted here is that in both cases of contamination level measurement and moisture content measurement, the measured values are affected by changes in oil temperature.

For example, the normal oil temperature of a certain oil-based hydraulic fluid is about 45°C, but it is allowed to go up to about 20°C in the initial stage of startup waiting, and it is natural that the oil temperature will rise to this temperature or on the way to 45°C. The degree of oil deterioration may be measured even during the temperature stage, so a measuring method or measuring device must be used that is not affected by oil heating.

However, in the case of contamination level measurement, changes in oil temperature appear as changes in oil viscosity, and the flow rate Q° at a certain time is actually affected by the oil temperature (2) as shown by the following equation.

Q'=f(ν” (T')/ν(T))XQwhere, ■
° is the oil temperature during measurement (e.g. 20°C in the initial startup wait), ■ is the oil '4 when the flow rate regulator is set (e.g. 45°C), ν and ν° are the kinematic viscosity coefficients at oil temperatures T and ■°, respectively. , Q is the flow rate (for example, 45° C.) when the flow rate regulator is set.

Although it depends on the viscosity characteristics of the hydraulic oil used as the oil temperature changes, the difference between Q" and O is often not negligible, and it may not be possible to accurately secure a constant volume V, which is the basis of the measurement principle. Generally speaking, when the oil temperature decreases, the viscosity of the hydraulic oil increases, making it impossible to secure a sufficient flow rate, and the degree of contamination tends to be lower.This tendency is not desirable in terms of the oil pipe ring. do not have.

In addition, in the case of moisture content measurement, assuming that the water vapor pressure is 1X1O-2kHz/- as mentioned above, the oil temperature is 45℃.
In the case of , the water content is about 600 PPM, but when the oil temperature is 20 °C, C = (1x10' /2.5 xlo-2)xo, 4
This means that it contains x10'=1600 PPM. In other words, even if hydraulic oil actually contains 1600 PPM of water at an oil temperature of 20°C, if the oil temperature is assumed to be 45°C, the apparent water content is 650 ppm.
This means that it only contains water from PPM, which poses a management problem similar to the degree of contamination.

The present invention has been made in response to such conventional circumstances, and even when the oil temperature changes, it is possible to measure the degree of oil deterioration with higher accuracy than in the past, and to manage oil properties more appropriately. The purpose of this invention is to provide an oil deterioration degree measuring device that can measure the degree of oil deterioration.

[Configuration of the Invention (Means for Solving Problems)] That is, the present invention provides an oil deterioration degree measuring device that samples oil and measures the degree of deterioration of the oil using a measurement sensor, which detects the temperature of the oil. The present invention is characterized by comprising a temperature detection means for detecting the temperature, and a correction signal generation means for outputting a correction signal according to the temperature detected by the temperature detection means and correcting the measurement result of the measurement sensor.

(Function) The oil deterioration level measuring device of the present invention having the above configuration includes a temperature detecting means for detecting the temperature of the oil, and a contamination degree measuring sensor, a moisture content sensor, etc. A correction signal generating means for outputting a correction signal to correct a measurement result of the measurement sensor is disposed in a measurement sensor such as a measurement sensor.

Therefore, even when the oil temperature changes, the degree of oil deterioration can be measured with higher accuracy than in the past, and the oil properties can be managed more appropriately.

(Example) Hereinafter, an example of the present invention will be described in detail with reference to the drawings.

FIG. 1 shows the configuration of an oil deterioration degree measuring device according to an embodiment of the present invention. A sample line 24 is provided, and this sample line 24 includes an oil temperature measurement sensor 25, a flow rate controller 26, a contamination level measurement sensor 27, and a moisture content measurement sensor 2.
8 are provided respectively.

Further, the oil temperature measurement sensor 25 is connected to the pollution level correction function calculation unit 2.
9 and a moisture content correction function calculating section 30, respectively, and the contamination degree measuring sensor 27 and the moisture content measuring sensor 28 are connected to a contamination degree measuring section 31 and a moisture content measuring section 32, respectively.

The outputs of the contamination degree correction function calculation section 29 and the contamination degree measurement section 31 are input to the multiplication section 33 and multiplied by the moisture content correction function calculation section 30 and the moisture content measurement section 32.
The output of is input to the multiplier 34 and multiplied. These multiplied values are each input to the determination section 35 and compared with a determination condition inputted in advance from the determination condition setting section 36, and the determination result is displayed on the display section 37.

In the oil deterioration level measuring device of this embodiment having the above configuration, the oil temperature measurement signal (M) from the oil temperature measurement sensor 25 is input to the contamination degree correction function calculation section 29 and the water content correction function calculation section 30, respectively. The pollution degree correction function calculation unit 29 and the moisture content correction function calculation unit 30 each calculate the pollution degree correction function f.
(T), generates a correction signal according to the moisture content correction function F(T).

FIG. 2 shows an example of the contamination degree correction interval (m). For example, when the oil temperature is 45°C, the correction coefficient K input to the multiplier 33 is 1, and the contamination degree measurement unit 31 The signal is input to the determination section 35 as is. Further, for example, when the oil temperature is 20° C., 1.1 is selected as the correction coefficient and is input to the multiplier 33 because of the influence of a decrease in flow rate due to the high viscosity of the oil. Therefore, the signal from the contamination level measuring section 31 is multiplied by 1.1 and input to the determining section 35.

Further, FIG. 3 shows an example of the moisture content correction interval F(T). For example, when the oil temperature is 45°C, the multiplier 3
4 becomes 1, and the signal from the moisture content measuring section 32 is inputted as is to the determining section 35. Furthermore, for example, when the oil temperature is 20°C, there is a difference in water solubility, so 2.5 is selected as the correction coefficient H.
The signal is input to the multiplication section 34. Therefore, the signal from the moisture content measuring section 32 becomes a value multiplied by 2.5, and the signal from the determining section 32 is multiplied by 2.5.
5 is input. For example, the moisture content measurement sensor 28
When the water vapor pressure of 1×1G−2h is 1011, the moisture content calculated by the moisture content measurement unit 32 is 650 PPM.
However, since it is multiplied by 2.5, it becomes approximately 1600 PPM, which is corrected to a normal value.

Note that the above correction functions f(T) and F(T) are based on the oil temperature during normal operation (approximately 45°C in this example); can be determined relatively easily by measuring the flow rate when the oil temperature is changed, or by investigating the change in water vapor pressure due to a change in oil temperature of oil whose water content is known in advance. In addition, in the above explanation, it is assumed that the oil temperature is 20°C at startup, but as is clear from Figures 2 and 3, the oil temperature may be higher than normal operation due to some reason. The same correction is made in this case.

In other words, the oil deterioration degree measuring device of this embodiment automatically corrects the temperature of the contamination degree and moisture content measurements not only at the oil temperature during normal operation, but also at oil temperatures in all operating conditions including startup. , which can be determined with high accuracy, greatly contributes to the management of hydraulic fluid.

In this embodiment, the oil temperature measurement sensor 25 is installed in the sampling line 26, but this is intended to measure the oil temperature as close to the flow rate controller 26 or the measurement section as possible. If the difference between the temperature of the oil in the oil tank 21 and the temperature of the oil in the oil tank 21 is small, the oil temperature in the oil tank 21 may be measured.

Furthermore, in this example, we have explained the case where the degree of contamination and moisture content are measured as the degree of oil deterioration, but the measured values may vary due to other factors during continuous monitoring, such as changes in oil temperature such as viscosity and specific gravity. It goes without saying that the present invention can also be applied to factors that may be affected.

[Effects of the Invention] As explained above, according to the oil deterioration degree measuring device of the present invention, even when the oil temperature changes, it is possible to measure the degree of oil deterioration with higher accuracy than in the past. properties can be managed more appropriately.

[Brief explanation of the drawing]

Fig. 1 is a configuration diagram showing an oil deterioration degree measuring device according to an embodiment of the present invention, Fig. 2 is a graph showing a contamination degree correction function, Fig. 3 is a graph showing a moisture content correction function, and Figs. FIG. 5 is a configuration diagram showing a conventional oil deterioration degree measuring device, and FIG. 6 is a characteristic diagram showing the relationship between the temperature of the hydraulic oil and the steam pressure of the saturated water-containing layer. 21... Oil tank 22... Hydraulic oil 23... Oil pump 24... Sampling line 25 ...
...Oil temperature measurement sensor 26 ...Flow rate controller 27 ...Contamination level measurement sensor 28 ...
...Moisture content measurement sensor 29...
- Pollution degree correction function calculation section 30...Moisture content correction function calculation section 31...Pollution degree measurement section 32...Moisture content Quantity measurement part 33.34・
...Multiplication section 35... Judgment section 36... Judgment condition setting section 37...
...Display Department Applicant Toshiba Corporation Patent Attorney Sa Suyama - Figure 2 Figure 3 Figure 4 Figure 5 Figure 6

Claims (2)

[Claims] (1) An oil deterioration degree measuring device that samples oil and measures the degree of deterioration of this oil using a measurement sensor, which includes a temperature detection means for detecting the temperature of the oil, and a temperature detection means according to the temperature detected by the temperature detection means. An oil deterioration degree measuring device comprising: correction signal generating means for outputting a correction signal to correct the measurement result of the measurement sensor. (2) The measurement sensor is a pollution degree measurement sensor and a moisture content measurement sensor, and the correction signal generation means is provided for each of these sensors. Oil deterioration degree measuring device.