JPS5942441A - Sensor for monitoring clouding of oil - Google Patents

Abstract

PURPOSE:To enable the senible, sure and continuous detection of the degree of contamination of a hydraulic fluid, lubricating oil, etc. by detecting the change in the electric resistance by the foreign matter which intrudes into the oil and has conductivity or magnetism. CONSTITUTION:A sensor is formed by arranging electrodes 2A, 2B respectively alternately in a comb shape on one surface of a nonconductive substrate 1 and vapor depositing plural lines of thin film resistors in such a way as to be spaced approximately equally and in parallel. A magnet 3 is provided on the opposite surface of the substrate 1. The substrate 1 is beforehand arranged in a suitable position in oil, and the change in the electric resistance value between the electrodes 2A and 2B is measured.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an oil pollution monitoring sensor for electrically detecting the degree of contamination of hydraulic oil or lubricating oil of various machines such as various engines, hydraulic systems, machine tools, rotating machines, etc. .

For example, oil such as hydraulic oil or lubricating oil used in construction machinery is generated due to precipitation of impurities and additives contained in it, wear of various parts of the machine such as the engine and power transmission mechanism, and incomplete combustion of the fuel. Contamination occurs when metal powder, carbon, etc. are mixed in.

The nature of the pollution varies depending on the type of engine, oil, etc.

However, basically, the electrical conductivity of oil increases as contamination progresses.

Therefore, if the contaminated oil is continued to be used as it is, it becomes a major cause of extremely inconvenient troubles such as piston breakage, bearing seizure, oil and fuel leaks, and decreased output.

Therefore, it is necessary to prevent such trouble from occurring (normally, the oil is changed regularly (due to the degree of contamination), but in this case,
Oil that can still be used is often rejected, resulting in a large waste of oil resources.

Further, as a measure to prevent the above-mentioned troubles, for example, there is a method of periodically collecting sample oil from the lubricating oil system and analyzing the oil to detect the degree of contamination of the song.

However, in this method, a considerable amount of labor and time is required until the degree of contamination is detected, and it is extremely difficult to deal with unexpected troubles that occur before the degree of contamination is detected.

As mentioned above, this type of oil contamination not only hinders the operation of engines and machinery (11), but also has the risk of becoming a factor in the occurrence of serious accidents.

For this reason, it is necessary to take appropriate measures such as replacing the oil when oil contamination progresses, and for this purpose, it is necessary to constantly and continuously monitor the degree of oil contamination.

The present invention has been made in view of the above circumstances, and its main purpose is to provide an oil pollution monitoring sensor that can constantly and accurately detect the degree of oil pollution in hydraulic oil, lubricating oil, etc.

Another object of the present invention is that even if the amount of contaminants mixed into the oil is extremely small, the contaminants are rapidly concentrated in the sensing section, thereby ensuring that the degree of contamination can be detected in this case. Our goal is to provide a highly reliable oil spill monitoring sensor.

Another object of the present invention is to provide an oil pollution monitoring sensor that greatly contributes to early detection of causes of mechanical failure due to oil pollution, indication of appropriate oil change timing, promotion of other appropriate measures, extension of machine life, etc. It is in.

Hereinafter, preferred embodiments of the present invention will be described based on the drawings.

First, the oil pollution monitoring sensor illustrated in FIG.
0 and a magnet 6 provided on the opposite surface.

The pollution sensing element 2 in this case extends from a pair of opposing electrodes 2A, 2B, as shown in more detail in FIG.

These electrodes 2A and 2B each consist of a plurality of thin film resistors arranged in parallel with each other at approximately equal intervals, and are deposited on the substrate 1.

Therefore, the electrodes 2A and 2B in this case are formed in an alternating comb shape and are connected to the power supply V.

Thus, the sensor having the above structure is used while being attached to an appropriate location in the oil, such as an oil drain plug.

In this case, each electrode 2A connected to the power supply V as described above,
2B are electrically independent from each other.

Therefore, if the song is very clean, electrode 2A.

The voltage between 2B and 2B is maintained in an insulated state with no change.

However, if the electrodes become contaminated due to the contamination of conductive foreign matter such as worn metal powder from various parts of the machine, the contaminated foreign matter will cause the electrodes 2A, 2 to become contaminated.
．． 8 is short-circuited and becomes conductive.

In this case, the electrode 2
The electrical resistance values of A and 2B change.

By measuring the change in electrical resistance using a well-known N gas redundancy measurement means (not shown), the degree of oil pollution is automatically and continuously detected at all times.

At the time of detection, the paramagnetic substance contained in the foreign matter in the song is attracted by the magnetic filter under the substrate 1. Therefore, the mixed foreign matter containing the paramagnetic substance is the electrode 2A.

2B1, that is, rapidly a-contracted onto the pollution sensing element 2.

For this reason, even if there is a small amount of foreign matter mixed into the oil,
It is also possible to reliably detect the degree of oil contamination due to the contamination of minute amounts of foreign matter. Further, even in a static song, the degree of pollution can be reliably detected without requiring measures such as forced circulation of the oil.

In the above embodiments, the pollution sensing element 2 is not limited to the comb-shaped vapor deposited electrodes 2A and 2B, but also other continuous electrodes, such as ladder-shaped electrodes, or wires, non-conductive wires, and conductive materials interwoven with each other. It may also be used as a mesh structure (although in this case, similar effects can be obtained.

In the case of the oil pollution monitoring sensor illustrated in FIG. 8, a magnetoresistive element is used as the pollution sensing element 2.

The element 2 is made of a ferromagnetic metal thin film having a continuous ladder-like pattern, for example, and is deposited on the substrate 1, and is arranged on the substrate at right angles to the power source V in FIG.
It is connected to.

A bias magnet 61 is integrally mounted directly below the substrate 1. This magnet 31 may be attached to the side surface of the substrate 1 or the like.

Therefore, the sensor in this case is also used by being attached to a suitable location in the oil, for example, to the piping of the lubricating oil system.

In the case of such a sensor, as long as the oil is very clean, the electrical resistance of the dirt-sensing element or magnetoresistive element 2 remains constant and does not undergo any change.

However, when the oil becomes polluted, the relative magnetic field between the magnetoresistive element 2 and the bias magnet 6' changes due to a small amount of magnetically conductive material contained in the oil.

Therefore, the electrical resistance of the magnetoresistive element 2 changes. The electrical resistance value at this time is measured by the electrical measuring means as in the previous embodiment, so that the degree of oil pollution is automatically and continuously detected at all times.

In the case of this embodiment, as described above (since the magnetic substance contained in the foreign matter mixed in the oil is detected, the attraction force of the bias magnet 31 is The magnetic substance can be detected quickly and reliably by the additional force of .

In addition, in each of the above examples, for convenience of explanation, it was described that the oil pollution state was measured qualitatively, but it is also possible to quantitatively measure the oil pollution state by comparing and calculating the oil pollution state with quantitative data. be.

That is, the oil pollution monitoring sensor described in each embodiment may be used in combination with a meter or a microcomputer having an electronic circuit.

In this case, the meter or microcomputer inputs the electrical resistance detection signal from the oil pollution monitoring sensor and processes the data to set the oil change period according to the purpose, or to detect an abnormal increase in oil pollution. This enables various automatic controls caused by oil pollution, such as issuing warnings and warnings to stop operation.

As described above, according to the present invention, the degree of oil contamination of hydraulic oil, lubricating oil, etc. of various machines can be automatically detected based on changes in electrical resistance due to foreign substances such as S-electrical or magnetic substances mixed in the oil.

In particular, at the time of detection, the foreign matter in the oil is attracted and concentrated by the contamination sensing element by magnetic force, so even if the amount of foreign matter is small, the degree of oil pollution caused by the foreign matter can be constantly and sensitively and reliably detected.

Therefore, by being able to indicate an appropriate oil change time, it is possible to reduce the number of songs, ensure normal operation of the machine, and greatly contribute to predicting machine abnormalities and extending the life of the machine.

[Brief explanation of the drawing]

FIG. 1 is a side view of an oil pollution monitoring sensor according to a preferred embodiment of the present invention, FIG. 2 is a plan view thereof, and FIG. 8 is a side view of an oil pollution monitoring sensor according to another embodiment. 1 is a non-conductive substrate, 2 is a pollution sensing element, 6 is a magnet, 6'
is a bias magnet. Applicant: Caterpillar - one person other than Mitsubishi Corporation Figure 2 Figure 3

Claims (1)

[Claims] (1) An oil pollution monitoring sensor installed in oil such as hydraulic oil or lubricating oil of various machines to electrically detect the degree of pollution of the oil; A pollution sensing element that electrically traps and detects foreign matter such as a conductive substance or a magnetic substance and changes the electric resistance, and a pollution sensing element that is installed near the pollution sensing element to attract the mixed foreign matter to the pollution sensing element, or It is characterized by comprising a magnet for forming a magnetic field and a means for detecting a change in the electrical resistance of the pollution sensing element due to the mixed foreign matter, so that the degree of oil pollution can be automatically measured based on the change in the electrical resistance. Oil spill monitoring sensor. (2. In the sensor according to claim 1, the pollution sensing element is composed of a plurality of parallel electrodes arranged alternately and spaced apart from each other at approximately equal intervals, An oil pollution monitoring separator characterized in that a change in electrical resistance due to the accelerated attraction of foreign matter mixed inside is detected. (3) In the senna according to claim 1. ,
An oil pollution monitoring sensor characterized in that the pollution sensing element consists of a magnetoresistive element, and a relative magnetic field is formed by a bias magnet. (4) In the sensor according to claims 1 to 8, by inputting an electrical resistance detection signal from the sensor, the signal is data-processed to quantitatively calculate the degree of pollution. An oil pollution monitoring sensor characterized by being equipped with automatic control means that takes predetermined measures according to the degree of pollution.