JPH09127067A - Oil tester - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an oil tester by which the degradation degree of an oil can be discriminated properly by transducing an electric signal into a sound- wave signal with a sound-wave transmitting element, transmitting the signal into the oil, receiving it with another sound-wave transmitting element and transducing it into an electric signal and judging the degradation degree of the oil from an output. SOLUTION: An electric signal, at about 20kHz or higher, which is transmitted from a transmitter 2 is amplified by an amplifier 3, an electrostrictive element 4 for transmitting is excited, and ultrasonic waves are generated. The ultrasonic waves are propagated inside an oil which is put into an oil tank 5 for measurement, they are received by an electrostrictive element 6 for reception, their electric signal is detected by a detector 7 so as to be amplified by an amplifier 8, and its voltage level is displayed by an indicator 9. The level is compared with a level in the case of a new oil, and the oil is judged to be degraded when the voltage level is low. In this manner, the degradation of the oil can be judged on the basis of change in the propagation factor of the ultrasonic waves without being affected by a coloring component or the like, and the existence of the degradation can be judged properly and simply.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an oil tester for measuring the degree of deterioration of lubricating oil such as engine oil, gear oil, torque converter oil, brake oil, and other hydraulic oils for automobiles, construction machinery, aircraft and the like. .

[0002]

2. Description of the Related Art Conventionally, the degree of deterioration of lubricating oil such as automobile engine oil has been measured by collecting a part of the oil and visually judging the degree of coloring. However, according to this, the degree of determination is different and unstable depending on the atmosphere in which the oil is visually observed or the person.

There is also a method in which light from a light emitting element is transmitted through oil to be measured, is received by a light receiving element, and the degree of deterioration of engine oil is detected from the degree of decrease in the amount of light received. For example, Japanese Utility Model Laid-Open No. 55-60554 discloses an oil monitor that passes the light of a fluorescent lamp through engine oil, detects this with a CDS (light receiving element), and measures the degree of deterioration of the oil by the amount of light that passes through the engine oil. Have been described. Also,
Japanese Unexamined Patent Publication No. 63-266342 describes an oil deterioration degree detecting device that combines the measurement of absorbance using infrared light or visible light and the measurement of absorbance using light having a wavelength of 6 μm. Further, Japanese Patent Laid-Open No. 2-194351 discloses a device for detecting deterioration of oil due to transmission of light, which is hermetically sealed by a main body 1 of an oil detecting portion and a lid 2 having a convex portion 2a fitted therein. There is described an oil deterioration detecting device that constitutes the oil detecting space 3 and that the light from the light emitting element 6 reaches the light receiving element 7 through the oil detecting space 3 to measure the deterioration degree of oil.

However, the oil deterioration detecting device utilizing these changes in the light transmittance is apt to cause a measurement error, particularly when measuring an oil containing a large amount of an additive such as a basic detergent. There was a problem that the measurement error was large. This is because the light transmittance is affected by the discoloration of oil. In particular, the oil containing the basic detergent turns black in a short time, so it is not possible to determine the appropriate replacement time, and in fact, the oil that has hardly deteriorated and maintains sufficient lubrication capacity is judged as deteriorated oil. Then, the resources are wasted and the resources are wasted and the costs are increased accordingly.

[0005]

SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide an oil tester capable of appropriately and easily determining the degree of deterioration of oil such as engine oil used in automobiles, construction machinery, aircraft and the like. To do.

[0006]

An oil tester of the present invention receives a sound wave signal that has passed through oil and a first sound wave transmitting element that converts an input electric signal into a sound wave signal and outputs and outputs the sound wave into the oil. And a second sound wave transmitting element for converting into an output electric signal, and the deterioration degree of oil is determined from the output signal from the second sound wave transmitting element.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail with reference to the drawings.

FIG. 1 is an overall schematic view showing an oil tester 1 according to an embodiment of the present invention. The oil tester 1 basically comprises an ultrasonic wave transmitter A including a transmitter 2, an amplifier 3 and a transmission electrostrictive element 4, a measuring oil tank 5, a reception electrostrictive element 6, a detector 7, an amplifier 8 and It is composed of a reception measurement unit B including an indicator 9. The electrostrictive elements 4 and 6 as elements for transmitting ultrasonic waves are so-called electrostrictive types, and are made of, for example, barium titanate or lead zirconate titanate. It is also possible to use those consisting of Rochelle salt or ADP, or of the so-called magnetostrictive type, for example of nickel, AF alloys or ferrites, or of the electromagnetic type. This also applies to the embodiment shown in FIG.

In the oil tester 1, the transmitter 2
An electric signal of, for example, a sine wave or a rectangular wave of about 20 kHz or more transmitted by the amplifier 3 is power-amplified by the amplifier 3, whereby the transmission electrostrictive element 4 is excited and an ultrasonic wave of the above frequency is generated. After propagating this ultrasonic wave in the oil injected into the measuring oil tank 5, the ultrasonic wave is received by the receiving electrostrictive element 6, converted into an electric signal, detected by the wave detector 7, and amplified by the amplifier 8. The voltage of is displayed by the indicator 9. That is, the sound wave propagating through the oil is read by the indicator 9 as a voltage level, and it is determined that the oil is deteriorated when the voltage is lower than that of new oil, that is, the ultrasonic wave propagation rate is low. Become.

The factors that cause the difference in the propagation of ultrasonic waves between the new oil and the deteriorated oil are considered as follows.

Generally, the deterioration index of lubricating oil is (1) generation of sludge composed of fine insoluble matter (so-called carbon) of n-pentane and wear metal powder due to mixing of fuel after combustion into oil, (2) Viscosity changes due to oil molecule cleavage due to deterioration, (3) Increase in total acid value due to oxidation of oil components, and
(4) It is said that the total base number decreases due to the consumption of lubricating additives.

On the other hand, the propagation rate of ultrasonic waves in oil changes with changes in sludge content and oil viscosity.
Therefore, the propagation rate of ultrasonic waves is lowered in the oil whose viscosity is lowered due to the generation of sludge or the cutting of the oil molecules of the oil due to the deterioration. Further, due to such a change, the resonance point of oil also changes. Therefore, the degree of deterioration can be determined by the change in the propagation rate of ultrasonic waves in the oil.

In the present invention, as a sound wave used for measuring the degree of deterioration of oil, an ultrasonic wave (20 kH) which transmits information accurately although it is usually straight and has a weak propagation force.
z or more) is used. However, when inspecting an oil having a large molecular weight such as a lubricating oil used in a large plant, a sound wave in an audio frequency band of 20 kHz or less may be used. In this case, a speaker or the like is used as a sound wave transmitting element. .

Furthermore, if the resonance point (frequency at which the sound wave propagation rate is highest) of new oil is measured in advance and the sound wave of this frequency is measured, the output level value becomes large, and the measurement becomes easier accordingly.

The oil tester of the present invention is free from contamination by wear metal powder and reduction in viscosity of engine oil, gear oil, torque converter oil, brake oil, and other hydraulic oils for automobiles, aircrafts, construction machines and the like. It can be used to measure offending oils.

The oil tester of the present invention may be an independent device in which each part is housed in a housing case, or may be a mounted type device in which each part is installed inside an automobile or the like. . Further, it may be a device incorporated in an oil exchanger.

As the material of the oil tank, it is preferable to use a material whose density is not extremely high with respect to the oil to be measured, preferably a material having a density equal to or lower than that, for example, a synthetic resin. This is because it is considered that most of the ultrasonic waves are conducted from the transmitting electrostrictive element to the receiving electrostrictive element through the oil tank itself when using a material having a density extremely higher than that of oil, such as a metal material. Is. Particularly preferred oil tank materials are synthetic resins such as polypropylene resins, nylon resins, acetal copolymers and the like. For example, an acetal copolymer sold under the trade name of DURACON can be used.

[0018]

The present invention will be described below with reference to examples.

Embodiment 1 FIG. 2 is a diagram showing a circuit of an oil tester 10 according to an embodiment of the present invention. In the figure, 12 is a transmitter, 13 is a frequency counter, 14 is a transmission electrostrictive element, 15 is an oil tank, 16 is a receiving electrostrictive element, 17 is a synchroscope, 18 and 19 are 1.1 KΩ resistors, respectively.
Is a 103 pF capacitor. Both electrostrictive elements 1
Nos. 4 and 16 are embedded in flanges 31 which are attached to both ends of the oil tank 15 in a sealing manner.

FIG. 3 is a sectional view showing the measuring oil tank portion 11 of the oil tester 10 of FIG. The measurement oil tank portion 11 is formed by embedding a transmission electrostrictive element 14 and a reception electrostrictive element 16 at both ends of a tubular oil tank 15 made of nylon resin and having both ends closed. An oil injection port 21 having a thread groove is formed on the side wall of the oil tank 15, and the oil injection port 21 can be opened and closed by a cap screw 22.

Next, the operation of the oil tester will be described.

A new commercially available automobile engine oil (for example, oil U manufactured by Company A) was poured from the oil inlet 21 of the oil tank 15 in FIG. 3 to fill the oil tank 15 with the engine oil.
An electric signal of 2 MHz and 10 V was emitted from the oscillator 12, and the output level displayed on the synchroscope 20 was read. Similarly, with respect to the oil U after traveling 10,000 km, the output level displayed by transmitting an electric signal of 2 MHz and 10 V was read.

Further, regarding other kinds of automobile engine oils V manufactured by Company A, automobile engine oils X and Y manufactured by Company B, and new oils after running 10,000 km, 2
The output level displayed by transmitting an electric signal of 10 MHz at 10 MHz was read. Table 1 shows the results.

[0024]

[Table 1] Output level (mV) Automotive engine oil New oil Oil after running 10,000 km U (A company) 15 5 V (A company) 15 5 X (B company) 13 4 Y (B company) 15 6 As is clear from Table 1, the output levels of the new oil and the oil after running 10,000 km are significantly different. Therefore,
The deterioration of oil can be clearly determined. It is considered that when the oil deteriorates, the molecules of the oil are cut, the viscosity of the oil decreases, the oil density decreases, and the output level decreases. On the other hand, the sludge in the oil settles at the bottom of the oil tank during the measurement, so that it does not affect the increase of the oil density and does not unnecessarily increase the output level. Next, it will be shown symbolically using air and water that the output level of the ultrasonic wave varies depending on the density of the medium according to the comparative example.

Comparative Example: The output level was measured in the same manner as in Example 1 except that the oil tank in FIG. 3 was filled with air and water instead of engine oil. Table 2 shows the results.

[0026]

[Table 2] Filling material output level (mV) Air 0 Water 54 From Table 2, air with a minimum specific gravity does not propagate ultrasonic waves, and in the case of water with a large specific gravity, ultrasonic waves can be well propagated. Is clear.

[0027]

According to the present invention, deterioration of oil such as engine oil can be judged by the fluctuation of the ultrasonic wave propagation rate, and such judgment is not easily influenced by the coloring component in the oil. Therefore, it is possible to properly and easily determine whether or not the oil has substantially deteriorated.

[Brief description of the drawings]

FIG. 1 is an overall schematic diagram showing an embodiment of an oil tester of the present invention.

FIG. 2 is a diagram showing a circuit of an embodiment of the oil tester of the present invention.

FIG. 3 is a cross-sectional view showing a measurement oil tank portion of the oil tester of FIG.

[Explanation of symbols]

 1, 10 Oil tester 2, 12 Transmitter 4, 14 Transmission electrostrictive element 5, 15 Oil tank 6, 16 Reception electrostrictive element 9, 17 Indicator

Claims (3)

[Claims] 1. A first sound wave transmitting element for converting an input electric signal into a sound wave signal and transmitting and outputting the sound wave in oil, and a second sound wave transmitting element for receiving a sound wave signal passing through the oil and converting it into an output electric signal. An oil tester, comprising: a sound wave transmitting element, and determining the degree of deterioration of oil from an output signal from the second sound wave transmitting element. 2. The oil tester according to claim 1, wherein the sound wave signal is an ultrasonic wave signal. 3. The oil tester according to claim 1, wherein the sound wave signal is an audible frequency sound wave signal.