JP3266637B2 - Method and apparatus for judging degree of deterioration of lubricating oil - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for judging the degree of deterioration of a lubricating oil. Specifically, the color of the lubricating oil is measured using light transmission, and a lubricating oil score is obtained based on information on the color and a constant set in advance according to the oil type. The present invention relates to a method and apparatus for judging the degree of deterioration of a lubricating oil, which is adapted to judge the deterioration and fouling state of oil.

[0002]

2. Description of the Related Art In order to accurately manage lubricating oil, it is necessary not only to observe the lubricating oil in use with the naked eye, but also to measure the amount of impurities in the lubricating oil and the color of the lubricating oil. It is important to accurately and quickly determine the deterioration and fouling state of a lubricating oil by performing a chemical analysis. Conventionally, when judging the deterioration or fouling state of lubricating oil, the lubricating oil in use at the site was sampled, carried to a test room where the sample lubricating oil could be analyzed and evaluated, and subjected to various analytical evaluations. The deterioration and fouling state of the lubricating oil were determined from the evaluation items.

[0003]

However, the conventional method has the drawbacks that it requires a lot of manpower and time and is not instantaneous. In addition, among the evaluation items, the color of the lubricating oil is effective for indicating the status of contamination by contaminants and the degree of deterioration of the lubricating oil itself.
As seen in JIS K2580, evaluation by eyes was easy for individual differences, and the color tone was constant. The measured values were stair-like and had a problem quantitatively.

On the other hand, Japanese Patent Publication No. 3-32013 proposes measuring the degree of deterioration of a lubricating oil by utilizing light transmission. However, this type projects light onto a sample lubricant placed in a container, receives the transmitted light from the sample lubricant by a light receiving element and converts it into an electric signal. Since the degree of deterioration of the lubricating oil is output, only the absorbance of the sample lubricating oil is measured, and at present, it is not possible to accurately grasp the subtle color types and changes of the lubricating oil.

[0005] It is an object of the present invention to provide a method of determining the degree of deterioration of a lubricating oil which can solve such a conventional problem and can quickly and accurately determine the deterioration and contamination of the lubricating oil without individual difference. Is to do. It is another object of the present invention to provide a lubricating oil deterioration degree determination device having a simple and portable structure in addition to the above objects.

[0006]

Therefore, a method of determining the degree of deterioration of a lubricating oil according to the present invention comprises projecting light onto a lubricating oil placed in a sample cell and dividing transmitted light transmitted through the lubricating oil into three parts. After each light is passed through a filter, it is converted into an electric signal to obtain tristimulus values of color. One of these Y and the chromaticity coordinates x and y obtained from the tristimulus values and the sample lubricating oil are used. Based on constants A, B, C, and D preset according to the type, the lubricating oil score is calculated as follows : Lubricating oil score = A + B × Y + C × x +
D * y, and the deterioration and fouling state of the sample lubricating oil is determined based on the lubricating oil score.

[0007] Further, the lubricating oil deterioration degree judging device of the present invention comprises:
A light source for projecting light onto the sample lubricant put in the sample cell, an integrating sphere for dividing transmitted light transmitted through the sample lubricant into three, and an optical path for each light divided by the integrating sphere are provided. A filter, a photoelectric conversion element for converting light passing through each filter into an electric signal, and first calculating means for obtaining a color tristimulus value and chromaticity coordinates based on the electric signal converted by each photoelectric conversion element. One of the tristimulus values Y and the chromaticity coordinates x and y obtained by the first calculating means and constants A, B, C and D set in advance according to the type of the sample lubricating oil. A second calculating means for obtaining a lubricating oil score indicating deterioration and fouling of the sample lubricating oil from the following formulas : Lubricating oil score = A + B × Y + C × x + D × y, and a second calculating means. Output means for outputting the obtained lubricating oil score.

Here, the light source may be any one capable of continuous projection such as a tungsten lamp or a halogen lamp, or one capable of instantaneous projection such as a pulsed xenon lamp. Absent. The sample cell for storing the sample lubricating oil may be made of glass or an inexpensive disposable acrylic cell, and preferably has an optical path length of 10 to 20 mm.
This is because measurement errors tend to occur if the length is less than 10 mm.
If the diameter exceeds mm, not only does the required amount of sample lubricant increase, but it is not possible to cope with a dark sample lubricant.

[0009]

In the measurement, after the sample lubricating oil is put into the sample cell, light is projected on the sample lubricating oil through the sample cell. Then, the transmitted light that has passed through the sample lubricating oil is divided into three, and after each light passes through a filter, it is converted into an electrical signal to obtain a color tristimulus value.
Next, a lubricating oil score is determined based on chromaticity coordinates obtained from one of these and the tristimulus value and a constant preset according to the type of the sample lubricating oil. Specifically, the color
One of the tristimulus values Y, obtained from the tristimulus values
Set in advance according to the chromaticity coordinates x, y and the type of sample lubricant.
Based on the obtained constants A, B, C, D
Score = A + B × Y + C × x + D × y. Obedience
Therefore, the lubricating oil score is a value that does not vary according to the oil type.
It is not necessary to make corrections based on the oil type.
In addition , regardless of the oil type of the sample lubricating oil, it is possible to quickly and accurately determine the deterioration and the contamination state of the sample lubricating oil based on the lubricating oil score without individual difference.

[0010]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 shows a lubricating oil deterioration degree determining apparatus according to the present embodiment. The device for determining the degree of deterioration of the lubricating oil includes a colorimetric system 10 having substantially the same principle as that of a normal color difference meter, and a lubricating oil score calculating system 20 constituted by a microcomputer or the like. Is formed. The sample lubricating oil 1 is made of a light-transmitting acrylic sample cell 2 having an optical path length of about 10 mm.
It is set at a predetermined position in the colorimetric system 10 while being kept in the printer.

The colorimetric system 10 includes a light source 11 composed of a tungsten lamp (commercially available) for projecting light onto the sample lubricating oil 1 placed in the sample cell 2, and a transmitted light transmitted through the sample cell 2 and the sample lubricating oil 1. Integrating sphere 12 that divides
And JIS Z8722 inserted into the optical path of each light divided into three by the integrating sphere 12 and according to each characteristic.
Filters 13A, 13B, and 13C, and a photoelectric conversion element 14 that receives light passing through each of the filters 13A, 13B, and 13C, and converts the light into an electrical analog signal.
A, 14B, 14C, and each photoelectric conversion element 14A, 14
A / D converter 15 for converting analog signals from B and 14C into digital signals, and tristimulus values X, Y and Z of colors are obtained from the digital signals converted by A / D converter 15 and further obtained. From the tristimulus values X, Y, Z, the chromaticity coordinates x,
and an arithmetic processing unit 16 as first arithmetic means for obtaining y. The integrating sphere 12, the filter 13
As A to 13C, photoelectric conversion elements 14A to 14C, A / D converter 15, and arithmetic processing unit 16, small ones used in an ordinary color difference meter are used.

Here, the tristimulus values X, Y, and Z of the color are XY
Z color system [Commission Internationale
de l'Eclairage, abbreviation CIE), recommended in 1931. Hereinafter, it is called an XYZ color system. ]]. The chromaticity coordinates x and y can be obtained from x = X / (X + Y + Z) (1) y = Y / (X + Y + Z) (2) Note that the Y and the chromaticity coordinates x and y of the tristimulus values in the XYZ color system are absolute data representing the colors, and do not particularly require correction by the measurement object.

The lubricating oil score calculation system 20 includes an operation panel 21 for selecting an oil type brand of the sample lubricating oil 1 to be measured.
A memory 22 for presetting and storing a plurality of types of lubricating oil score calculation formulas corresponding to the oil type brand of the sample lubricating oil 1 selected by the operation panel 21 and storing the calculation results and the like; The lubricating oil score arithmetic expression selected from the plurality of types of lubricating oil score arithmetic expressions stored in the storage unit 22 among the tristimulus values of the XYZ color system determined by the arithmetic processing unit 16 of the colorimetric system 10. One (Y) and the chromaticity coordinates x, y are substituted into the arithmetic processing unit 23 as a second arithmetic unit for obtaining the lubricating oil score of the sample lubricating oil 1, and the lubricating oil obtained by the arithmetic processing unit 23 And a display device 24 as output means for displaying the score.

Here, the oil type brand of the sample lubricating oil 1 is, for example, oil type-01 is machine oil A, oil type-02 is hydraulic oil A, oil type-03 is hydraulic oil B, and oil type-04 is oil. Compressor oil A, .....
As shown in FIG. Therefore, the memory 22
In the table, 10 types of lubricating oil score calculation formulas are set and stored in advance corresponding to the oil type brand of the sample lubricating oil 1. The lubricating oil score calculation formula is as follows. Lubricating oil score = A + B × Y + C × x + D × y (3) where Y, x, and y are tristimulus values and chromaticity coordinates of the XYZ color system, and A, B, C, and D are oil brands. Is the constant set in. The constants A, B, C, and D are set to different values for each oil type brand. That is, in the above formula (3), the lubricating oil score is 100 in the state of the new oil, and 50 in the state of the oil renewal management standard (use limit state in which the oil is replaced with the new oil).
Constants A, B, C, and D are set for each oil type brand.

Now, according to the order of the measurement procedure shown in FIG. 2, first, the sample lubricating oil 1 is put into the sample cell 2, and the sample cell 2 is set at a predetermined position in the colorimetric system 10. In this state, when light is projected from the light source 11,
The transmitted light transmitted through the sample cell 2 and the sample lubricating oil 1 is divided into three by the integrating sphere 12. Each light is filtered 1
After passing through 3A, 13B and 13C, the A / D converter 15
Is converted into a digital signal and input to the arithmetic processing unit 16. Here, tristimulus values X, Y, and Z are obtained.
The chromaticity coordinates x, y are obtained based on the tristimulus values X, Y, Z. Next, in the arithmetic processing unit 23 of the lubricating oil score calculating system 20, the tristimulus value Y and the chromaticity coordinates x, y are substituted into the lubricating oil score calculating formula previously selected according to the oil type, and the lubricating oil score is calculated. A score is obtained, and the lubricant score is stored in the memory 22 and displayed on the display device 24.

Therefore, by reading the lubricating oil score displayed on the display device 24, the degree of deterioration and contamination of the lubricating oil 1 can be quickly and accurately grasped from the read value without individual difference. In addition, since the lubricating oil score is displayed as a numerical value that does not vary depending on the oil type, there is no need to correct the oil type, and the point at which the lubricating oil score reaches 50 is the state of the oil renewal management standard. When the numerical value of the lubricating oil score displayed on the display device 24 reaches 50, it can be determined as the oil renewal time. Therefore, anyone can accurately and promptly determine the timing of refueling. Further, in terms of the configuration, a small color measurement system 10 having substantially the same principle as the color difference meter and a lubricating oil score calculation system 20 configured by a microcomputer or the like are formed in a portable size as a whole. , The user can carry it to the site and measure the degree of deterioration of the lubricating oil there.

Therefore, the effects of the present invention will be described with reference to an experimental example and a comparative example in which the lubricating oil deterioration degree judging apparatus shown in FIG. To reveal.

EXPERIMENTAL EXAMPLE 1 The machine oil A of oil type-01 was used in an actual machine, and the progress up to the state of oil renewal control standard (state of lubricating oil rating 50) was examined. Specifically, a sample was taken every elapse of a predetermined operation time, and the kinematic viscosity, ASTM color, total acid value, insoluble content, and Millipore contaminants of the sample were measured. The lubricating oil score was determined using a judging device. The results are shown in Table 1 and FIG. In addition,
In Table 1, the ASTM color in which "L" is added before the measured value is 0.25
Is shown as a measured value (the same applies to the following experimental examples). In this case, the formula for calculating the lubricating oil score is as follows: Lubricating oil score = 181.0−0.1217 × Y−369.8 × x + 188.0
× y.

[0019]

[Table 1]

From these results, the determination of the oil renewal timing cannot be detected based on kinematic viscosity, total acid value, insoluble matter, and Millipore contaminants, etc. In addition, the measured value of the ASTM color is stepwise and varies. Although it is possible to finally detect and judge, the lubricating oil score shows that the tendency can be quantitatively grasped and the oil renewal can be judged very easily. Also, from the results, the lubricating oil score almost corresponds to the ASTM color, and the quality of the sample lubricating oil can be easily grasped on site without having to carry the sample lubricating oil to the test room as in the case of the ASTM color. We can see that we can do it.

EXPERIMENTAL EXAMPLE 2 With respect to hydraulic oil A of oil type-02, it was used in an actual machine, samples were taken at predetermined operating time intervals, and the kinematic viscosity, ASTM color, total acid number, base number and wrinkles of the oil were measured. The measurement was performed, and the lubricating oil score was obtained using the lubricating oil deterioration degree determination device shown in FIG. The results are shown in Table 2 and FIG.

[0022]

[Table 2]

From the results, not only the judgment of the correspondence between the lubricating oil score and the ASTM color, but also the fact that the lubricating oil score of 50 set as the oil renewal standard was reached, the increase in the total acid value and the poor foaming property It can be seen that it is now possible to make predictive judgments on poor quality such as lubrication oil scores.

EXPERIMENTAL EXAMPLE 3 Two types of hydraulic oil B of oil type-03 and compressor oil of oil type-04
For the species, 20 samples each of which are used in the actual machine,
Seven samples were taken and the ASTM color and lubricant score were determined for each sample. The result is shown in FIG. From these results, for each oil type, the lubricating oil score well corresponds to the ASTM color, and some of them reached the lubricating oil score of 50 set as the oil renewal standard. It can be seen that as the fouling progresses, the lubricating oil score shows a lower quality than the hue change with higher sensitivity.

COMPARATIVE EXAMPLE 1 For the same oil type as in Experimental Example 3, the new oil was not set to the zero point, and the dark air phase was set to the zero point.
The absorbance was measured as in No. 013. That is, since Y among the tristimulus values obtained inside the lubricating oil deterioration degree determination device shown in FIG. 1 corresponds to the visible light transmittance of the sample lubricating oil,
This signal was further converted to absorbance so as to be obtained as measurement data. FIG. 6 shows the results in correspondence with the ASTM colors.

From these results, the evaluation based on the absorbance was determined by AS
It was also found that the correlation with the TM color was lower than the correlation coefficient with the lubricating oil score of Experimental Example 3, indicating that it exhibited unique data. This indicates that, in the present invention, not only the tristimulus value Y but also the tristimulus values Y and Z necessary for calculating the chromaticity coordinates x and y are required.

Comparative Example 2 The same oil type as in Experimental Example 3 was placed in a glass sample cell 2 having an optical path length of 10 mm, and a spectrum of 450 to 750 nm was measured using a commercially available spectrophotometer. Was measured for absorbance. FIG. 7 shows the results in correspondence with the ASTM colors. From this result, it was found that the evaluation based on the absorbance at a specific wavelength was lower in the correlation with the ASTM color than the correlation coefficient with the lubricating oil score of Experimental Example 3, and that the quality change of the lubricating oil was captured. Is difficult.

In the above description, the constants A, B, and B in the equation (3) are set so that the lubricating oil score in the equation (3) is 100 in the state of the new oil and the state of the oil change management standard is 50.
Although C and D are set for each oil type, the numerical values of the lubricating oil score in the state of the new oil and the state of the oil renewal management standard are not limited to the above examples, and can be set arbitrarily.

Further, in the above example, ten lubricating oil score calculation formulas are set and stored in the memory 22, but the number of lubricating oil score calculation formulas set and stored in the memory 22 is limited to the above example. However, it may be arbitrary.

[0030]

As described above, according to the method for determining the degree of deterioration of a lubricating oil according to the present invention, the state of deterioration and contamination of the lubricating oil can be determined without difference between individuals.
In addition, the determination can be made quickly and accurately. Further, according to the lubricating oil deterioration degree judging device of the present invention, a simple and portable structure can be provided.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an embodiment of a device for determining a degree of deterioration of a lubricating oil according to the present invention.

FIG. 2 is a flowchart showing a measurement procedure.

FIG. 3 is a view showing a property change of a machine oil A of oil type-01.

FIG. 4 is a view showing a change in properties of a hydraulic oil A of oil type-02.

FIG. 5 is a diagram showing a correlation between a lubricating oil rating and an ASTM color for two types of hydraulic oil B of oil type-03 and compressor oil 2 of oil type-04.

FIG. 6 is a diagram showing the correlation between the absorbance by Y and the ASTM color for two types of hydraulic oil B of oil type-03 and compressor oil 2 of oil type-04.

FIG. 7 is a diagram showing the correlation between the absorbance at 650 nm and the ASTM color for two types of hydraulic oil B of oil type-03 and compressor oil 2 of oil type-04.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Sample lubrication oil 2 Sample cell 10 Colorimetry system 11 Light source 12 Integrating sphere 13A, 13B, 13C Filter 14A, 14B, 14C Photoelectric conversion element 15 A / D converter 16 Arithmetic processing unit (1st arithmetic means) 20 Lubricating oil Rating system 21 Operation panel 22 Memory 23 Processing unit (second processing unit) 24 Display unit (output unit)

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) G01N 21/00-21/01 G01N 21/17-21/61 G01J 3/00-3/52 Practical file ( (PATOLIS) Patent file (PATOLIS)

Claims (2)

(57) [Claims] A light is projected onto a sample lubricating oil placed in a sample cell, transmitted light transmitted through the sample lubricating oil is divided into three, each light is passed through a filter, and then converted into an electric signal. And the chromaticity coordinates x and y obtained from one of these Y and the tristimulus values , and constants A, B, C, and D preset according to the type of the sample lubricant. Oil score = A + B x Y + C x x + D x y
And determining whether the sample lubricating oil is degraded or soiled based on the lubricating oil score. 2. A light source for projecting light onto a sample lubricating oil placed in a sample cell, an integrating sphere for dividing transmitted light transmitted through the sample lubricating oil into three, and an optical path of each light divided by the integrating sphere. A filter provided therein, a photoelectric conversion element that converts light passing through each filter into an electric signal, and a tristimulus value and chromaticity coordinates of a color based on the electric signal converted by each photoelectric conversion element. 1 and one of the tristimulus values Y and the chromaticity coordinates x, y of the tristimulus values obtained by the first calculating means.
And a constant A preset according to the type of the sample lubricant ,
Based on B, C, and D , the lubricating oil score indicating the deterioration and fouling of the sample lubricating oil is calculated as follows : Lubricating oil score = A + B × Y + C × x + D ×
A lubricating oil deterioration degree judging device comprising: a second calculating means obtained from y; and an output means for outputting the lubricating oil score obtained by the second calculating means.