JPH05180766A - Apparatus for inspecting contamination degree of hydraulic oil - Google Patents

Abstract

PURPOSE:To judge the contamination degree of oil to be inspected by applying high frequency voltage across electrodes to measure electric impedance and measuring light transmissivity by a light emitter and a photodetector and inputting these measured values to a microprocessor to compositely judge the contamination degree of the oil to be inspected. CONSTITUTION:When an inspection container 1 filled with a water-soluble hydraulic oil 6 to be inspected is at the optimum measuring temp., high frequency voltage is applied across electrodes 5, 6 by conductive contacts 11, 12. The electric impedance change due to the oxidative deterioration of the oil, the reduction of additives or the reduction of moisture is detected as the amplitude change of high frequency voltage appearing across both terminals of a load condenser 25 and this voltage value is compared with the reference value being the measured value of new oil to be judged. At the same time, the light transmissivity of the oil 6 is measured by a light emitter 15 and a photodetector 16 arranged in opposed relationship and compared with the reference value being the measured value of an empty container to judge the contamination degree of the oil 6. Next, the contamination degree of the oil 6 is compositely judged on the basis of the algorithm and judge standard preliminarily stored in a microprocessor 32 to be displayed by a display 33 and an OK lamp 34.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention is intended to reduce the water content of water-soluble hydraulic oil (water-glycol hydraulic oil, etc.) used in hydraulic equipment.
The present invention relates to a hydraulic oil fouling degree inspecting apparatus that can easily inspect the property change and the degree of fouling due to oxidative deterioration, reduction of additives, inclusion of foreign matter, etc., on site without being affected by temperature changes.

[0002]

2. Description of the Related Art In recent years, a large amount of flame-retardant water-soluble hydraulic oil is used in place of mineral oil in hydraulic equipment used in high temperature environments such as steelmaking and steelmaking plants in order to prevent fire accidents. It became possible to be. For example, a water-glycol hydraulic oil containing ethylene glycol as a main component is glycol 4
It was prepared with 0%, 40% water, and 20% additive. In order to operate hydraulic equipment smoothly, it is necessary to always grasp its properties and manage hydraulic oil appropriately. That is,
Water-soluble hydraulic oil causes problems such as clogging and seizure of hydraulic cylinders due to water loss, chemical changes (oxidative deterioration, etc.) and inclusion of foreign matter such as dust during the years of use. Therefore, the control of the water-soluble hydraulic fluid is extremely important.

Conventionally, this kind of oil agent management periodically samples oil from the oil tank and judges the degree of pollution by visual inspection or touch, or the oil agent manufacturer measures the degree of pollution (NAS grade inspection) and chemical analysis. (Water content, alkalinity value, p
H) was performed. However, in the former case, it is difficult to make a quantitative judgment and an accurate property judgment cannot be made. Further, the latter has a problem that it takes a lot of time and cost for the analysis and inspection, and the determination cannot be made directly on the spot. In addition, JP-A-63-
Japanese Patent No. 96546 discloses a water-soluble hydraulic oil in which a high-frequency voltage is applied to a water-soluble hydraulic oil interposed between electrodes to measure its electrical impedance and a change in the properties of the water-soluble hydraulic oil is detected from a change in impedance. A property inspection device has been proposed. However, the above-mentioned device has a problem in that chemical changes that cause changes in impedance, that is, water decrease, oxidative deterioration, and the like can be significantly detected, but dust and the like cannot be detected.

[0004]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and its object is to mix dust and other oil components of the water-soluble hydraulic oil to be measured. The degree of pollution is measured as a change in light transmittance, and chemical changes such as water loss and oxidative deterioration of new oil and measured oil are also measured as changes in electrical impedance. Can be performed, and at the same time, more accurate composite judgment can be performed,
An object of the present invention is to provide a contamination degree inspection device for hydraulic oil that can be easily used on site.

[0005]

To achieve the above object, in the present invention, a pair of electrodes arranged facing each other so as to come into contact with hydraulic fluid to be inspected, and a load connected in series to the electrodes. Oil impedance measuring means having a capacitor, a high-frequency power source for applying a high-frequency voltage to a series load composed of the load capacitor and the electrode, and a voltage detection circuit for detecting the amplitude of the high-frequency voltage generated across the load capacitor. A light emitting device and a light receiving device which are arranged to face each other with the hydraulic oil to be inspected interposed therebetween, a constant voltage power supply for making the light emitting device a constant light emission output, and a light receiving signal level of the light receiving device. An oil light transmittance measuring unit having a light detecting circuit for detecting, a temperature sensor arranged to detect the oil temperature of the working oil to be inspected, and a temperature detecting circuit for detecting the output of the temperature sensor. An oil temperature measuring means, an A / D converter to which output signals from the impedance measuring means, the oil light transmittance measuring means and the oil temperature measuring means are input, and an output signal of the A / D converter. And a display device for displaying the output of the microprocessor. Based on the output signals from the impedance measuring means, the oil light transmittance measuring means and the oil temperature measuring means, There is provided an oil pollution degree inspection device for hydraulic oil, comprising: an oil pollution degree determination unit that determines the pollution degree of inspection hydraulic oil.

Further, the oil pollution degree judging means stores a reference value storing means for storing the measurement results of the impedance measuring means and the oil temperature measuring means for a new hydraulic oil, and a light transmittance in an empty container. In the empty container light transmittance storage means for measuring and storing, the light transmittance storage means for measuring and storing the light transmittance of the hydraulic oil to be inspected, and the stored light transmittance and the empty container light transmittance storage means. Transmittance determination means for comparing and comparing the stored light transmittance, temperature storage means for measuring and storing the temperature of the hydraulic oil to be inspected, and new oil for storing the stored temperature in the reference value storage means. Temperature judging means for judging that the temperature of the working oil is within a predetermined range by comparing with the temperature of No. 1, impedance storing means for measuring and storing the impedance of the hydraulic fluid to be inspected, and the stored impedance and the reference value storing means. Good May comprise a comparator determining the impedance determining means and impedance, and a defacement degree determination display means for displaying determines defacement degree of the inspected hydraulic oil by combined determination of the impedance determining means and transmission determining means.

[0007]

When foreign matter such as dust or oil component is mixed in the water-soluble hydraulic oil, the light transmittance is lowered. Further, the high frequency impedance changes when a chemical change such as a decrease in water content, an oxidative deterioration, or a decrease in additives occurs. The change in high frequency impedance is
Optimal measurement conditions are obtained in the temperature range of 20 to 25 ° C. This is because when the temperature is 20 ° C or lower, the viscosity of the hydraulic oil becomes high and the electrochemical phenomenon when voltage is applied becomes slow and it takes time for the measured value to stabilize. The viscosity becomes low, the electrochemical phenomenon becomes active when a voltage is applied, and the difference in high-frequency impedance due to a chemical change is less likely to occur. For the determination of chemical changes due to high frequency impedance, the method of comparing and determining the measured values of new hydraulic oils of the same brand and the same type and the measured oils is the most accurate, and accurate pollution degree determination is possible. It will be possible.

The operation of the device of the present invention is based on the above findings, and the operation is as follows. In the oil impedance measuring means, a high frequency voltage is applied between the electrodes in which the hydraulic oil to be inspected is present, and a value corresponding to the high frequency impedance of the hydraulic oil to be inspected is measured as a voltage value generated across the load capacitor. The oil light transmittance measuring means measures the light transmittance of the working oil to be inspected, and the oil temperature measuring means measures the oil temperature of the working oil to be inspected. These measured values are input to the microprocessor via the A / D converter, and the degree of contamination of the hydraulic fluid to be inspected is determined by the processing of the microprocessor.

Further, the high-frequency impedance of the new hydraulic oil is measured and stored in the contamination degree judging means of the hydraulic oil, and the high-frequency impedance of the new hydraulic oil is compared with the high-frequency impedance of the hydraulic oil to be judged. Further, the temperature of the new hydraulic oil and the temperature of the hydraulic oil to be inspected are measured and compared. Further, the light transmittance of the empty container and the light transmittance of the hydraulic oil to be inspected are measured and compared. The degree of pollution of the hydraulic oil to be inspected is determined by the composite determination of these comparison determinations.

[0010]

Embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a perspective view showing the appearance of a container 1 for inspecting the degree of contamination of hydraulic oil (hereinafter referred to as inspection container 1), and FIG. 2 is a sectional view. The inspection container is made of a transparent acrylic resin and has a substantially rectangular shape with an upward opening. Two walls 2 and 3 made of transparent acrylic resin that face each other in parallel are provided above the inspection container.
Are formed to form a light passage portion. The lower part of the inspection container is formed narrow, and aluminum plates 4 and 5 are fixed and hermetically sealed in the window portion of the acrylic resin. The left and right aluminum plates 4 and 5 face each other at regular intervals to form an electrode portion. When the oil 6 is injected into the inspection container 1,
As shown in FIG. 2, the oil 6 is filled up to the passage of light.

FIG. 3 is a block diagram of the pollution degree inspection device showing the measuring jig 10 in cross section. The measuring jig 10 is provided with conductive contacts 11 and 12 having a leaf spring structure.
The left and right aluminum plates 4 and 5 are slidably contacted with each other so as to be electrically conductively contacted. A thermistor 13 for temperature measurement is arranged on the back surface of one of the conductive contacts 12, and the inspection container 1
The temperature of the oil 6 inside the aluminum plate 5 and the conductive contact 12
It is designed to be able to measure using the heat conduction of. A light emitter 15 and a light receiver 16 are arranged on the upper surface of the measurement jig 10 so as to face each other on both sides of the light passage portion of the inspection container 1.
In front of 5, a lens 17 for converging light is provided. The lens 17 may be arranged in front of the light receiver 15.

A light emitter 15 composed of a light emitting diode is connected to a DC power source 21 and emits light with a predetermined illuminance. Receiver 1
Reference numeral 6 denotes a phototransistor, which is connected to the photodetector circuit 22 and outputs a signal according to the amount of received light. Thermistor 1
3 is connected to the temperature detection circuit 23 and outputs a signal corresponding to the detected temperature. Conductive contacts 11 and 12 having a leaf spring structure
One of the conductive contacts 11 is connected to a high frequency power supply 24, and the other conductive contact 12 is a load capacitor 25.
And is connected to the voltage detection circuit 26. As the high frequency power source 24, for example, one having a frequency of 20 KHz and 5 V is used, and as the load capacitor 25, one having a capacity having an impedance similar to that of fresh oil is desirable. The outputs of the light detection circuit 22, the temperature detection circuit 23, and the voltage detection circuit 26 are input to the A / D converter 31, converted into digital values, and then the microprocessor 32.
Entered in. The microprocessor 32 determines the degree of contamination of the hydraulic oil 6 based on an algorithm and determination criteria stored in advance and displays it on the display 33 and the OK lamp 34. A key switch 35 for inputting necessary data is connected to the microprocessor 32.

The operation will be described based on the above configuration. According to this configuration, when the water-soluble hydraulic oil to be inspected is at the optimum measurement temperature, by applying a high-frequency voltage to the electrodes 4 and 5, its electric power which changes due to oxidative deterioration of the oil, additive decrease, water decrease The change in impedance is detected as the change in the amplitude of the high frequency voltage appearing across the load capacitor 25, and the voltage value is compared with the measured value of fresh oil as a reference value to determine the degree of change in the property of the oil. At the same time, the light transmittance of the test water-soluble hydraulic oil is measured by the light emitter 15 and the light receiver 16 which are arranged to face each other, and the light transmittance is compared with a reference value to determine the degree of contamination. Next, the complex degree of contamination in which a plurality of oil items are mixed is accurately and quickly determined by making a composite determination of the degree of change in the property of the oil and the degree of contamination.

Next, the criteria for determining the light transmittance will be described. The light transmittance in the empty container 1 is set to 100%, and the light transmittance when the water-soluble hydraulic oil 6 to be inspected is put in the container 1 is examined.
As shown in Table 1, if the transmittance is 40% or more, it is indicated by a circle, which means that it is normal and can be continuously used. Transmittance is 40% or less 1
If it is 0% or more, it is indicated by a triangle and contamination is in progress and caution is required. When the transmittance is 10% or less, it is indicated by a cross mark, and precise analysis or replacement of oil is required. Oil with a light transmittance of 10% or less
It has been empirically found that blackening occurs due to oxidation and the inclusion of foreign matter, and turbidity occurs due to the inclusion of mineral oil and a large amount of dust.

[0015]

Next, the criteria for determining the voltage value Vs appearing across the load capacitor 25 indicating the voltage impedance will be described with reference to Table 2. The voltage with new oil is Vo
Then, the determination is made based on the amount of deviation from the new oil value Vo. When the voltage value Vs when the water-soluble hydraulic oil 6 to be inspected is put in the container 1 is within ± 5% of the new oil value Vo, it is marked with a circle, and it is normal and can be continuously used. Voltage value Vs is ± 5% or more of new oil value Vo ± 10
If it is less than%, it is indicated by a triangle and contamination is in progress and caution is required. When the voltage value Vs deviates from the new oil value Vo by ± 10%, it is marked with an X and must be replaced. When the voltage Vs is higher than the new oil value Vo by 10% or more, the PH value of the oil is greatly decreased due to the oxidation deterioration and the decrease of the additive for adjusting the alkali value, and conversely, the voltage Vs is the new oil value. It has been empirically found that the water content is greatly reduced when Vo is lower than 10%. It is also possible to detect the phase difference between the high-frequency voltage signal applied to the electrodes and the high-frequency voltage signal appearing across the load capacitor 25, and detect the impedance of the oil from the magnitude of the phase difference.

[0017]

Next, a composite judgment is made based on the judgment results shown in Tables 1 and 2. In the composite judgment, the above ○ mark, △ mark, ×
As shown in Table 3, comprehensive judgment is made for 9 cases depending on the combination of marks. Voltage value Vs is ± 1 from new oil value Vo
When the difference of 0% or more occurs, the determination of the light transmittance is ignored and the result is NG. This is because there are large changes in properties such as oxidation and water loss that cannot be visually determined as deterioration of fouling of hydraulic oil, so it is judged that component adjustment or replacement is necessary, and performance deterioration as hydraulic oil is emphasized. Next, the light transmittance of 10% or less is NG. This is because visual contact is good and the degree of contamination due to mixing of foreign matters and discoloration is high, which may cause mechanical damage to hydraulic equipment, and it is judged that oil cleaning or replacement is necessary. △
The mark and the combination of the mark and the mark and the mark are judged to be CHK, and the mark is the mark. Contamination is ongoing and caution is required. Only the combination marked with ◯ is OK, and it is judged to be normal.

[0019]

FIG. 4, FIG. 5, and FIG. 6 are flowcharts showing the processing in the microprocessor that realizes the above control concept. When the inspection device is operated and the processing is started, step 1 (hereinafter abbreviated as S1 and the like) is entered, and a self-check operation is started. First, the light emitter 15 composed of a light emitting diode is turned on and its output is measured. If the output is below the specified value, the process proceeds from S2 to S3, and it is determined that the LED is defective or the optical system is contaminated.
Be instructed to. Next, the output voltage of the high frequency power supply is measured,
If it is less than the specified value, the process proceeds from S4 to S5, and it is determined that the power supply is defective and is displayed. If the power supply is OK, the process proceeds to S6. S6
Then, the measurement is carried out using a new oil of the same brand and type as the tested water-soluble hydraulic oil. Since "new oil measurement" is displayed on the display 33, new oil is injected into the inspection container 1 and set in the inspection device. When key switch 35 is turned on, S7 to S8
Then, the high frequency voltage from the high frequency power supply 24 is applied to the electrodes 4, 5,
The voltage Vo of the condenser 25 and the oil temperature To of fresh oil are measured after a predetermined time after being applied to the oil and are stored in the memory in the microprocessor 32 in S9.

The next operation is an operation for adjusting the light transmittance to 100%. When the empty inspection container 1 is set on the measuring jig 10 and the key switch 35 is turned on, the process proceeds from S10 to S11, the light emitter 15 is turned on and the display 33 displays "100".
"% Measuring" is displayed and the light transmittance of the empty inspection container 1 is measured. If the light transmittance is 50% or less, it is determined that the surface of the inspection container 1 is contaminated, and the process proceeds from S12 to S13, and the display 33 gives a work instruction such as cleaning. Light transmittance is 50
If it is more than%, the process proceeds to S14 and the display 33 displays "Sample oil set". The next operation is a light transmittance measurement operation of the hydraulic oil to be inspected. When the sample oil is injected into the inspection container 1 and set in the inspection jig 10 and the key switch 35 is turned on, the process proceeds from S15 to S16, and the display 33 is displayed.
Is displayed as "% measuring", the light emitter 15 is turned on, the light transmittance is measured after a predetermined time, and the light transmittance is displayed in% on the display 33, and it is measured and stored at the time of 100% adjustment in S11. The light transmittance of the empty inspection container is compared and judged, and the judgment result and the light transmittance are stored in the memory of the microprocessor 32 (S17, S18, S1).
9).

Next, when the key switch 35 is turned on, S20
From S to S21, the light emitter 15 is turned off, the display 33 displays "Oil temperature measurement", and the oil temperature measurement operation starts. The temperature Ts of the sampled hydraulic fluid to be inspected is determined by the thermistor 13
Detected by S8 and compared with the temperature To of the fresh oil measured in S8. If the temperature Ts of the hydraulic fluid to be inspected is within To ± 2 ° C, the process proceeds to the next S24. However, the temperature Ts is To
If it is other than ± 2 ° C, the process proceeds to S23, in which the oil is heated or cooled by a thermostatic device (not shown) and set to a predetermined temperature. Next, when the key switch 35 is turned on, S24 to S
25, a high frequency voltage is supplied from the high frequency power source 24 to the electrode 4,
5 is applied, and the display 33 displays “Vs measuring”. After a predetermined time, the voltage Vs of the condenser 25 is measured and compared with the voltage Vo of the fresh oil measured in S8, and the determination result and the measured value Vs are displayed on the display 33 and stored (S26, S27, S2).
8).

Next, when the key switch 35 is turned on, S29
From S30, the high frequency power supply 24 is turned off, and the display 33 displays "Comprehensive determination". The comprehensive judgment is a composite judgment as shown in Table 3 based on the judgment result of the light transmittance and the judgment result of the voltage value Vs based on a predetermined judgment criterion. The result is OK in S31.
On the lamp 34, OK (good), CHK (caution), NG
The LED lamp is lit and displayed in three stages of (replacement). Next, when the key switch 35 is turned on, S32 to S3
3, the display 33 displays "START?", And is in a state of waiting for the measurement of the next hydraulic fluid to be inspected.

[0024]

The present invention has the above-mentioned structure and is provided with the impedance measuring means of oil, the light transmittance measuring means of oil, and the temperature measuring means of oil to judge the pollution degree of the hydraulic oil to be inspected in a complex manner. Therefore, there is an excellent effect that it is possible to easily determine the degree of contamination of the hydraulic oil, which does not vary from person to person, on site.

[Brief description of drawings]

FIG. 1 is a perspective view showing the appearance of a container for inspecting the degree of contamination of hydraulic oil.

FIG. 2 is a sectional view of an inspection container.

FIG. 3 is a block diagram of a pollution degree inspection device showing a measurement jig in section.

FIG. 4 is a flow chart showing processing by a microprocessor.

FIG. 5 Flow chart

FIG. 6 Flow chart

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Inspection container 2, 3 Two wall surfaces 4 and 5 made of transparent resin 4, 5 Metal plate constituting electrode part 11, 12 Conductive contactor 13 Thermistor 15 Light emitting device 16 Light receiving device 32 Microprocessor

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Tatsuo Moribe 1 Wanowari, Arao-cho, Tokai-shi, Aichi Aichi Steel Co., Ltd. (72) Inventor Takashi Sagae 1 Wano-wari, Arao-cho, Tokai-shi, Aichi Inside Steel Co., Ltd. (72) Inventor Mitsuaki Iwai 1 Wano Wari, Arao Town, Tokai City, Aichi Prefecture Aichi Steel Co., Ltd.

Claims (1)

[Claims] 1. A high frequency is applied to a pair of electrodes, which are arranged so as to face each other so as to come into contact with the hydraulic oil to be inspected, a load capacitor connected in series to the electrode, and a series load including the load capacitor and the electrode. A high frequency power supply for applying voltage,
An impedance measuring means of oil having a voltage detecting circuit for detecting the amplitude of a high frequency voltage generated at both ends of the load capacitor; a light emitting device and a light receiving device which are arranged so as to face each other with the working oil to be inspected interposed therebetween. An oil light transmittance measuring means having a constant voltage power source for making the light emitter emit a constant light output, and a light detection circuit for detecting a light reception signal level of the light receiver; Oil temperature measuring means having a temperature sensor arranged to detect the temperature and a temperature detecting circuit for detecting the output of the temperature sensor, the impedance measuring means, the oil light transmittance measuring means and the oil temperature. A / D to which the output signal from the measuring means is input
A converter, a microprocessor to which an output signal of the A / D converter is input, and a display device on which the output of the microprocessor is displayed are provided, and the impedance measuring unit, the oil light transmittance measuring unit, and An oil pollution degree inspection device comprising: an oil pollution degree judging means for judging the pollution degree of the hydraulic oil to be inspected based on an output signal from the oil temperature measuring means.