JPH0572121A - Oil contamination detecting device - Google Patents

Abstract

PURPOSE:To detect the degree of oil contamination with high precision and high reproducibility by specifying the oil width in which light passes through and the wave length range of the detection light. CONSTITUTION:An oil contamination detector is constituted by specifying the oil width for the transmission of light to 5mm or less in order to measure a variety of oil with high precision, and specifying the wave length range of the detection light within a range of 600-1100nm, averting the wave length range where the light absorption varies strongly. For example, a plug type oil contamination monitoring device installed in an oil circuit detects turbidity, on the basis of the light transmissivity in the case where the light supplied from a luminous element 1 installed in an inside cavity is allowed to pass through the oil 2 and detected by a luminous element 3. The peak wave length of the measurement light is within a range of 600-1100nm, specifically at 880nm. The width of the oil. 2 in which light passes through can be adjusted to 5mm or less according to the kind of the measured oil by an adjusting shim 4.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an oil pollution detecting device, and more particularly to an oil pollution detecting device capable of detecting oil pollution degree in-line with high accuracy and reproducibility.

[Prior Art]

[0002] Conventionally, as an oil pollution detecting device of this type, the explanation will be given with reference to Fig. 3, in which a light emitting portion 1 and a light receiving portion 3 are provided, and light from the light emitting portion 1 is transmitted through oil 2 and received There is a configuration in which the pollution degree of the oil is detected based on the light transmittance at the time of being detected by the section 3 (for example, Jikho Sho 57-116).
852).

Light from the light emitting section 1 is absorbed and scattered by the oil according to the degree of contamination of the oil. That is, the amount of light received by the light receiver 3 is smaller than the amount of light emitted by the light emitter 1 depending on the degree of contamination of the oil. In other words, if the degree of pollution of the oil is different, the degree of absorption and scattering of light by the oil is different, and the transmittance of light is also different.
The degree of contamination of the oil is detected by detecting the light transmittance of the oil and calculating the light transmittance of the oil.

In the above-mentioned conventional structure, the range of the oil width through which light is transmitted is usually about 1 mm, although there is no literature that specifies it. On the other hand, Japanese Patent Application Laid-Open No. 61-135913 discloses a document defining the measurement range of light. In this document, light with a wavelength of about 600 nm or more is measured.

[0005]

However, in the conventional oil pollution detecting device constructed as described above, it is not possible to detect oil pollution with good reproducibility as it is, as it is. Specifically, there is a large variation in detection, which is not practical.

[0006]

In order to solve the above problems, in the oil pollution detecting device according to the present invention, the oil width through which light is transmitted is 5 mm or less (the first feature), and The light to be detected has a wavelength of 600 nm to 1100 nm (second characteristic). As a result, the degree of oil pollution can be detected with high accuracy and reproducibility.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A most preferred embodiment of the oil pollution detecting device of the present invention will be described below with reference to FIGS.

FIG. 1 shows various oil widths (δ1) through which light is transmitted.
5 is a graph showing the oil pollution degree (horizontal axis) and its transmittance (vertical axis) in δ6. That is, this figure is a diagram for explaining the first feature of the present invention, where δ1 is the oil width of 60μ.
m, δ2 is oil width 70μm, δ3 is oil width 100μ
m, δ4 is 200 μm oil width, δ5 is 1 m oil width
m and δ6 represent the oil pollution degree and the transmittance thereof at an oil width of 5 mm. As can be seen from the figure, there is a correlation between the oil pollution degree, its transmittance, and the oil width. For example, the oil exchange standard for diesel engines is an oil pollution degree of about 3 wt% (pentane insoluble matter, etc.), but in order to detect this, an oil width of δ1 or δ2 is required according to the figure. . Even if it is attempted to detect with the oil widths δ3 to δ6, all the light is absorbed by the oil and it becomes impossible to detect. On the contrary, the standard for replacing the hydraulic oil (usually # 10W) for operating the hydraulic actuator is an oil pollution degree of about 0.5 wt%. In this case, in order to detect this, an oil width of about δ4 is required. More precise oil for hydraulic actuators requires an oil width of about δ5 or δ6. Although the above description is based on the oil exchange standard, as can be seen from the figure, in order to detect the degree of oil contamination successively with high reproducibility and with high accuracy, the oil width through which light is transmitted is 5 mm or less. You know what you need to do.

FIG. 2 is a graph showing the wavelength (horizontal axis) of the measuring light in the lubricating oil (# 30) and the transmittance (vertical axis) for each wavelength. That is, this figure is a diagram for explaining the second feature of the present invention. According to the figure, in the case of the same oil, light absorption appears in the wavelength range of about 400 nm to about 2400 nm. In other words, about 400 nm or less and about 2400
It can be seen that light is totally transmitted in the range of nm or more, and light in these ranges does not contribute to oil pollution detection. By the way, within this range, as shown in FIG.
nm to about 600 nm and about 1100 nm to about 2400 n
In the range of m, strongly varying absorption appears. As a result, if these ranges are included in the detection range, errors and variations will occur in the detection results. It should be noted that the light absorption characteristics of oil are somewhat different depending on the type of oil, but generally, light absorption appears in the wavelength range of about 400 nm to about 3000 nm, and about 400 nm to about 600 nm, about 120 nm.
0 nm, about 1400 nm, about 1700 nm, about 2200 nm to about 2300 nm and about 3000 n
The absorption of light strongly changes near m. Therefore, in most oils, by setting the range (R in the figure) in the wavelength range of 600 nm to 1100 nm as the transmittance measurement range,
Oil pollution can be detected with high accuracy and reproducibility.

FIG. 3 is an external view of an embodiment of the present invention.
An example is a plug-type oil pollution detection device provided in the oil circuit (that is, in-line) and constantly monitoring the oil pollution level. Specifically, the extension translucent light having the nut portion 51 and the screw portion 52 at one end, the flat end surface at the other end, and the light emitting element 1 (manufactured by Toshiba, TLN201) in the inner cavity and the both end surfaces being flat. A plug 5 having a member 11 and a cap 55 on the other end of the plug 5 so as to face the flat end surface of the other end of the plug 5, and the light receiving element 3 (made by Toshiba, TPS70
8) and an extending translucent member 31 having flat end surfaces, an adjusting shim 4 for adjusting a joint gap between the plug 5 and the annular member 53, and the plug 5 and the annular member 5.
3 and the adjusting shim 4 are integrally fixed to each other through a through bolt 54.

In the above embodiment, the width of the oil through which light is transmitted is 0.07 mm, but it can be set to 5 mm or less by adjusting the shim thickness.
The minimum value of the adjusted thickness is up to 50 μm in this embodiment. This is because the particle size of pollutants in oil is about 0.1 μm
This is because it is within the range of about 3 μm (since a high-mesh filter is additionally provided in the oil circuit, other foreign matter will not be clogged within the oil width). Moreover, the peak wavelength of the measurement light is 880 nm.

FIG. 4 is a graph showing the test results of the above examples. The test was carried out by mounting the above-mentioned embodiment on the side of the oil pan of the engine. The vertical axis of the figure is a measured value obtained by previously obtaining a calibration curve of the detector output and the oil pollution degree (wt%) and converting the detector output into the pollution degree from the curve. On the other hand, the horizontal axis is "Standa" of ASTM D893.
rd Test Method for INSOLUBLES IN USED LUBRICATINGS
It is a calculated value obtained by the method of "OILS", and it can be seen that both have a good correlation.

To describe the effects of the above embodiment, the following drawbacks of the prior art can be solved. (1) The width of oil through which light passes is not particularly limited and may be about 1 mm as long as it is limited to that for detecting oil pollution of light load machines such as ordinary automobiles. However, if you want to detect oil pollution with high accuracy or if you want to detect oil pollution for a machine that uses a wide variety of oils (each oil has different pollution standards) such as heavy-duty machines such as construction machinery, the light is transmitted. The oil width to be used must be determined appropriately. Therefore, in the present invention, the width of oil through which light is transmitted is set to 5 mm or less. (2) The measuring light may have a wavelength of 600 nm or more as disclosed in JP-A-61-135913, but the upper limit value is not specified (in other words, the same item simply indicates the lower limit value). I just identified it). However, as can be seen from the above description, oil has a wavelength range in which light is absorbed and scattered. That is, according to the same issue, since the light having a wavelength of the upper limit value or more is also measured, not only is the light of these wavelengths wasted, but also light of the wavelength region in which absorption strongly changes is detected, Errors and variations occur in the detection result. Therefore, in the present invention, the wavelength of the light to be detected is changed from 600 nm to 1
It was set to 100 nm.

[0014]

As described above, according to the oil pollution detecting device of the present invention, the light emission part and the light receiving part are provided, and the light emitted from the light emitting part is transmitted through the oil and detected by the light receiving part. In an oil pollution detection device that detects the degree of oil contamination based on the transmittance of oil, the oil width through which light is transmitted is 5 mm or less, and the light when detected has a wavelength of 600 nm.
To 1100 nm, oil contamination can be detected with high reproducibility and high accuracy.

[Brief description of drawings]

FIG. 1 is a diagram showing a first feature of the present invention, and is a graph showing oil pollution degree and transmittance in each oil width through which light is transmitted.

FIG. 2 is a diagram showing a second feature of the present invention, and is a graph showing the wavelength of the measurement light and the transmittance for each wavelength.

FIG. 3 is an external view of an oil pollution detection device according to an embodiment of the present invention.

FIG. 4 is a diagram showing test results of Examples of the present invention, and is a graph showing a correlation between an actually measured value and a calculated value of oil pollution.

[Explanation of symbols]

 1 light emitting part 2 light transmitting oil width 3 light receiving part

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Akira Mori 1200 Manda, Hiratsuka-shi, Kanagawa Komatsu Ltd. Research Laboratory

Claims (1)

[Claims] 1. An oil pollution detection device comprising a light emitting unit and a light receiving unit, and detecting the degree of oil contamination based on the transmittance of light when the light from the light emitting unit passes through the oil and is detected by the light receiving unit. In the device, the width of oil through which light is transmitted is 5 mm or less, and the light to be detected has a wavelength of 600 nm to 1 nm.
An oil pollution detection device characterized by a configuration of up to 100 nm.