JPS63266342A - Detector for degree of deterioration of oil - Google Patents

Abstract

PURPOSE:To measure a hexane insoluble component and degree of oxidation and to easily and exactly detect deterioration of oil by providing a means for measuring the absorbancy of IR light of 6mum wavelength in addition to a means for measuring the hexane insoluble component. CONSTITUTION:A light source 1 which emits IR light and optical sensors 3, 4 consisting of pyroelectric elements are disposed on both sides of light transparent windows which are disposed to face each other to a part of the wall of an oil supplying pipe and consist of silicon. An optical sensor 2 consisting of a pyroelectric element is disposed as a sensor for reference near the light source 1. An optical filter 5 which consists of an alumina sheet and allows the transmission of only the light of 6mum wavelength is disposed in front of the optical sensor 4. The outputs of the optical sensors 2, 3 and the outputs of the optical sensors 2, 4 are respectively inputted to differential ampifiers 7a, 7b. Then, the hexane insoluble component is detected from the output of the sensor 3 and the degree of oxidation (total acid value) is detected from the output of the optical sensor 4.

Description

Detailed Description of the Invention [Industrial Application Field] The present invention relates to an oil deterioration degree detection device, and in particular detects components that are not dissolved in hexane or hebutane mixed in engine oil, etc., and components that are oxidized by heat using infrared rays. This invention relates to a device that measures absorbance.

[Prior art and its problems]

In order to maintain and sustain smooth operation of the engine over a long period of time, engine oil is supplied as lubricant to each sliding part of the engine, and this is usually done through circulation lubrication using an oil pump. There are many things.

Due to frictional heat caused by sliding during continued use,
Engine oil deteriorates.

This type of engine oil deterioration is caused by oxidative deterioration, which is a change in the properties of the oil itself, and the consumption of various additives, as well as the intrusion of combustion products into the oil and the dispersion of wear debris from various parts. .

If this continues to be used, there is a high possibility that it will lead to engine failure, so drivers are required to detect deterioration of the engine oil and change the oil.

The conventionally proposed method for detecting the degree of deterioration of engine oil is a method that uses a color sensor for visible light and utilizes light absorption in the visible range (Japanese Patent Publication No. 60-2360).
48), and one that utilizes light absorption of ultraviolet light of 300 to 400 nm (Japanese Patent Publication No. 57-100739).

In addition, by using a photocell for visible light and a photocell for infrared light as the light detection means, and detecting the attenuation of both visible light and infrared light, we can detect the color of oil without being affected by coloring. A method for determining the amount of particle components has also been proposed (Japanese Unexamined Patent Publication No. 101744/1983).

All of these methods utilize light attenuation based on absorption and scattering by colored particle components of engine oil. The colored particle components are reaction products such as soot, abrasion powder, oxides, etc., and resins (hereinafter referred to as hexane-insoluble components) that are insoluble in nonpolar organic solvents such as hexane and pentane.

This amount of hexane insoluble matter differs depending on the combination of fuel and engine oil, and as shown in Figure 8, with certain kerosene a, there is almost no increase in hexane insoluble matter even after 300 hours have passed. On the other hand, with other kerosene or heavy oil C, it can be seen that the amount of hexane insoluble matter increases considerably after 300 hours.

As is clear from this figure, it is not necessarily correct to uniformly determine the degree of deterioration only by measuring the amount of hexane insoluble matter.

As described above, there is a problem with detection accuracy in detecting the degree of deterioration of engine oil by measuring hexane-insoluble matter using infrared light and visible light. Standard values had to be changed accordingly.

The present invention has been made in view of the above-mentioned circumstances, and an object of the present invention is to provide an oil deterioration degree detection device that can easily perform measurements and obtain highly accurate measurement results.

[Means for solving problems]

Therefore, in the present invention, in addition to the hexane-insoluble measurement method, oxidation degree measurement is performed to measure the absorbance of a component containing a carbon-oxygen double bond C-0, such as an alkyl ketone (R2O-0), at a wavelength of 6 μm. Based on the results of both measurements, it is determined whether the oil has deteriorated or not.

[Effect]

The present inventors determined the relationship between the total acid value, that is, the amount (mg) of potassium hydroxide (KOH) required to neutralize 1 g of oil, and the absorbance of infrared light with a wavelength of 6 μm. As shown in FIG. 6(a), it was found that there was a linear relationship, and by focusing on this and measuring the absorbance at a wavelength of 6 μm, oxidative deterioration of the oil was detected.

Therefore, it is possible to detect oxidative deterioration, which could not be detected by conventional hexane-insoluble measurements alone, and it is possible to easily and accurately detect oil deterioration.

FIG. 6(b) is a diagram showing the relationship between the alkaline value and the absorbance of light with a wavelength of 6 μm, which was measured for reference.

In addition, Figure 7 (a) shows the results of measuring the relationship between hexane-insoluble powder (wt%) and absorbance for infrared light (1.5 to 11 μm) (Figure 7 (b) is a partially enlarged view of FIG. 7(a)), which also shows a good linear relationship, indicating that infrared light absorption is suitable for detecting hexane-insoluble matter. By measuring the absorbance of infrared light in this way, it is possible to satisfactorily measure the content of hexane-insoluble powder.

〔Example〕

Embodiments of the present invention will be described in detail below with reference to the drawings.

FIG. 1 is a diagram illustrating the principle of an engine oil deterioration degree detection device according to an embodiment of the present invention.

This device includes a light source 1 made of a nichrome wire coil that emits infrared light, a first optical sensor 2 made of a pyroelectric element disposed near the light source 1 and detecting the light emitted by the light source,
It consists of second and third optical sensors 3 and 4 made of pyroelectric elements that detect light from the light source 1 through engine oil, which is an object to be detected. An optical filter 5 made of a (A12O3) plate that transmits only light with a wavelength of 6 μm is provided, and the outputs of the second and third optical sensors 3 and 4 and the output of the first optical sensor as a reference sensor are In comparison, the output of the second optical sensor 3 is used to detect hexane insoluble matter, and the output of the third optical sensor is used to detect the degree of oxidation (total acid value). It is.

Here, 6 is an ON-OFF signal circuit as a lighting circuit for the light source, and 7a and 7b are the output of the first optical sensor and the second
and a logarithmic differential amplifier that compares the outputs of the optical sensor and the third optical sensor, and outputs these outputs to a signal processing circuit (not shown) that determines deterioration.

Further, as detection points, transparent windows 9a and 9b made of silicon are arranged opposite to a part of the tube wall of the oil supply vibrator 8 to each sliding part of the engine, and these windows 9a, 9
A light source 1 and second and third optical sensors 3,
4.

Here, with no oil in the oil supply vibrator 8, the 0 points and spans of the first, second, and third optical sensors are set to match 1. Then, the output intensities II+12+I3 of the first, second, and third optical sensors when oil is present have a relationship as shown in the following equations.

1, m(o...(1
)12 m11 exp (dxc Xf)
・-(2) p p 13-11 exp (dxc(1xfo) -=
(3) Concentration of hexane-insoluble substances in C-nitrogen, f Sensitivity of the sensor to hexane-insoluble substances in C-nitrogen, co Concentration of components containing C-〇 double bonds such as R2C-0 in C-nitrogen: Sensitivity of sensor to component d: window spacing From formulas (1), (2), and (3), dXc Xf −In I2 /I+ ・”
(4) p p dXc,)XfO-In I3 /I+ ・” (
5) Therefore, the outputs of the first optical sensor and the second optical sensor,
By differentially amplifying the outputs of the first optical sensor and the third optical sensor, the concentration of hexane-insoluble components in the oil and the concentration of components containing C-〇 double bonds in the oil are detected. can do.

Figures 2 (a) and (b) show the detection results of the degree of oil deterioration, that is, the concentration of C-0 component and the concentration of hexane-insoluble powder, when engine oil 5AEIOWSE-CD for high temperature and high load use is used in a diesel engine. show. The vertical axis shows absorbance and the horizontal axis shows engine test time.

Here, the absorbance of 2
Since the oil was changed at the appropriate time after 02 hours, the relationship curve has become discontinuous at this point.

In this way, the degree of deterioration of engine oil can be detected with high precision very easily.

In addition, as an optical filter, as shown in Fig. 3, a wavelength of 6μ
Since an alumina plate is used which has sharp transmission characteristics for light of m, detection is extremely easy.

In the example, the degree of deterioration of engine oil 5AEIOWSE-CD for diesel engines was detected, but it goes without saying that it can also be used in combinations of other engine oils and engines, and oxidative deterioration is generally a problem. It can also be used to detect the degree of deterioration of edible oil.

Figure 4(a) shows the C-0 component concentration when using other engine oils for diesel engines.
FIG. 3 is a diagram showing the relationship between the absorbance of light (vertical axis) and elapsed time (horizontal axis). For comparison, FIG. 4(b) shows the results of conventional deterioration detection using infrared absorbance. Figures 4(a) and (
The comparison in b) also shows that oil deterioration, which could not be detected using conventional methods, can be easily detected using the apparatus of the present invention.

Furthermore, FIGS. 5(a) and 5(b) respectively show 6μ when using engine oil found in a methanol engine.
The results of measuring the relationship between m-light absorbance and elapsed time and the relationship between infrared absorbance and elapsed time are shown. In this case as well, oil deterioration that could not be detected by infrared absorbance alone
It can be detected by measuring the absorbance of light in μm.

Further, in the embodiment, a pyroelectric element is used to detect infrared light, but it goes without saying that the invention is not limited to the pyroelectric element and other detection elements may be used.

Further, the optical filter is not limited to an alumina plate, and any filter that transmits only light with a wavelength of 6 μm may be used.

Furthermore, the hexane insoluble power may be measured by measuring the absorbance of white light instead of infrared light.

In addition, in the example, it was used to detect the deterioration of engine oil, but it can also be used not only for engine oil but also for other devices such as process control devices that use cooking oil where oxidative deterioration of oil is a problem. be.

[Effect] As explained above, the oil deterioration degree detection W of the present invention
According to A@, in addition to the first method of measuring hexane insolubility, a second method of measuring the absorbance of infrared light with a wavelength of 6 μm
Therefore, in addition to measuring the hexane insoluble power, the degree of oxidation can be measured by the second means, and oil deterioration can be easily and accurately detected.

[Brief explanation of drawings]

FIG. 1 is a diagram showing an oil deterioration degree detection device according to an embodiment of the present invention, and FIG. 2(a) and FIG. Figure 3 shows the measurement results of the optical filter, Figure 4 (a) and Figure 4 (b) show the characteristics of the optical filter.
) are diagrams showing the detection results of oxidative deterioration and hexane insolubility of other engine oils detected using the apparatus in Figure 1, and Figures 5(a) and 5(b) are also diagrams showing the detection results of other engine oils, respectively. FIG. 6(a) is a diagram showing the relationship between the total acid value and the absorbance of light with a wavelength of 6 μm. Figure 6 (b
) is a diagram showing the relationship between the absorbance and the alkaline value, No. 7
Figures (a) and 7(b) are diagrams showing the relationship between hexane insolubility and infrared absorbance at a wavelength of 1.5 to 11 μm;
FIG. 8 is a diagram showing the relationship between the amount of hexane insoluble power and the engine usage time when the combination of fuel and oil is changed. DESCRIPTION OF SYMBOLS 1... Light source, 2... 1st optical sensor 3... 2nd optical sensor, 4... 3rd optical sensor, 5... Optical filter, 6 ・ON'-OF ( A circuit, 7a, 7
b-...logarithmic differential amplifier, 8...vibe, 9a, 9b
···window. Methano-J Reientes) 1 hour (H") Complete defeat I Nishi (to OHmg/9) Figure 6 (G) Test time (H") 7+1. Katana IJ (a (to OHmg/9) Figure 6 ( b
)

Claims (3)

[Claims] (1) Comprising a first absorbance measuring means for measuring hexane-insoluble matter and a second absorbance measuring means for measuring the absorbance of light with a wavelength of 6 μm, and the measurement results of the first and second absorbance measuring means An oil deterioration degree detection device characterized in that the oil deterioration degree is determined based on. (2) The first and second absorbance measuring means share a light source consisting of an infrared light generating means, and each of the first and second absorbance measuring means
and a second infrared light detection means, the second infrared light detection means comprising an optical filter that is transparent only to light with a wavelength of 6 μm. An oil deterioration degree detection device according to claim (1). (3) The optical filter is made of alumina (Al_2O_3)
The oil deterioration degree detection device according to claim 2, characterized in that it is made of a plate.