JPS60260838A - Instrument for measuring oil quality - Google Patents

Abstract

PURPOSE:To detect the deterioration of the quality of an oil easily and qualitatively by measuring the DC resistance or AC impedance of the oil. CONSTITUTION:This detecting instrument is constituted of a measuring electrode 4 consisting of a pair of counter electrodes 1, 1', a fixed voltage power source 5 of DC, AC or high frequency and an ammeter 6. An oil 2 to be measured is set between the measuring electrodes 4. In case of the oil of high purity and of less quantity of conductive molecule such as carbon, metal powder, impurity, etc., resistivity is higher and current I is hardly flowed, but the oil is deteriorated and impurity is increased, then, the impurity is charged like an ion current and moved between electrodes, and a current flows. With reading the current value thereof, the deterioration of oil can be detected qualitatively.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to an oil quality measuring device for simply electrically measuring and displaying the quality of lubricating oil for an engine or the like.

[Prior art]

BACKGROUND ART Conventionally, the degree of deterioration in the quality of engine oil for automobiles and the like has been mainly determined using sensual means such as human vision and touch.

As is well known, engine lubricating oil reduces the coefficient of friction by lubricating the rotating and sliding parts of the engine.
In addition to its direct lubricating effect to reduce mechanical loss, it also removes fine metal powder caused by wear, explosions, incomplete combustion of fuel that occurs due to combustion, such as trace amounts of gasoline, diesel oil, carbon, ash, etc. It has effects such as removing 5 oxides, preventing oxidation, and cooling the inside of the engine. Therefore, as the engine operates, the oil gradually contains carbon.

Fine metal powder, oxides, etc. increase, and oxidation progresses.

Therefore, although these impurities are removed using an oil filter or the like, it is not possible to completely remove them or prevent or reduce oxidation depending on the filter.

For this reason, as the number of such impurity particles increases, the lubricating effect gradually decreases, causing serious effects on engine functions such as seizure, and therefore, it is necessary to change the oil at an appropriate time.

[Problems with conventional technology]

Previously, there was no way to easily measure and inspect oil deterioration, and strictly speaking, it was necessary to check oil viscosity, oiliness, transparency,
Although analytical methods such as solid matter content PH existed, they were complicated and impractical.

Furthermore, even with optical detection means, it is difficult to judge oil deterioration based only on optical transparency. For this reason, in practice, in general, when checking the oil level in automobiles, the oil adhering to the oil gauge is visually judged by its color and transparency, or the particle size of impurities and the degree of contamination are judged by sensory methods such as touch. , or mileage, period, etc.
The replacement period was determined based on this.

However, oil fatigue and quality deterioration are actually due to traffic conditions.
There are many variations depending on driving conditions, etc.

For example, while there are severe usage conditions such as long-term high-speed operation or low-speed and long-term operation at high temperatures, there are also cases where it is used extremely rarely, so it cannot be determined simply and unambiguously.

Furthermore, in recent years engines have become smaller, lighter, and higher output.

Due to demands for low fuel consumption and low pollution, demands on oil are becoming increasingly severe, such as increased rotational speed and increased compression pressure.

For this reason, automobile manufacturers and oil dealers tend to instruct the oil to be replaced at a relatively early stage, assuming the most severe usage conditions.

On the other hand, users do not have a simple and clear way to judge when it comes to expensive oil changes, so they rely on the non-chemical, unilateral judgment of service shops even when they do not necessarily think it is the right time to change their oil. It is.

As described above, the quality control method for oil, which is important for the life of an engine, has been extremely incomplete in the past. The purpose of the present invention is to provide an oil quality measuring device that can reliably measure electrically.

[Key points of the invention]

In order to achieve the above-mentioned object, the present invention is equipped with a measuring device that measures the quality of a liquid substance such as oil by capturing it as a change in direct current resistance, alternating current, or high frequency impedance.

[Embodiments of the invention]

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

First, to briefly explain the principle, as shown in FIG.
It is defined as follows by ρ, specific resistance ρ, and specific dielectric constant ε.

R=ρD/S ・・・・・・・・・・・・(1) C=εS
/D ・・・・・・・・・・・・(2) Therefore, if the circuit is configured as shown in Fig. 1 and the DC voltage V (DC) is applied from the power supply 3, the current I (DC) will be 1 ( DC), =V/R=pS/D --(31).

Also, the alternating current or high frequency current 1 (AC/RF) is the vector sum of the effective loss current 1 (R) due to conductive impurity particles and I (C) flowing through the capacitance C, which is I (AC/RF) = I (R) - z (C).

・Here, ρ is the specific resistance of the oil, so it is usually extremely high when the oil is of high purity, and the current is extremely small. However, when the amount of conductive particles such as carbon, metal powder, impurities, etc. increases for the above-mentioned reason, these particles become charged like an ionic current and move due to the electric field between the electrodes, that is, become a current. As a result, the resistance value decreases and the current ■ increases.

Furthermore, the decrease in viscosity is as if these impurity particles were to move as charged particles in the electric field between the electrodes, reducing the amount of impurities to N
, the electric charge of the electron is q, and its mobility (mobility) is µ, then the particles become easier to move due to the decrease in viscosity, which contributes to an increase in current as shown in the following equation.

ρ=1/1 m−q·μ (6) Eventually, the degree of oil deterioration can be detected as an increase in current.

Therefore, if low cost, high sensitivity, and high precision are not required, the first option is
Measurement of direct current or alternating current or high frequency current I as shown in the figure,
Or display by comparing with the resistance value of reference oil. If even higher sensitivity is required, a bridge circuit as shown in FIG. 2 is used to measure the impedance between the measurement electrodes using a direct current, alternating current, or high frequency power source. In this case, the conductive particles are equivalent to the approach of the electrodes, and the capacitance C increases.

Furthermore, if high sensitivity is required, as shown in Figure 3, the capacitance C between the measurement electrodes can be used as part of an oscillation circuit, and the oscillation output can be tuned to be detected. The increase can be easily detected by a change in capacitance C, that is, a change in frequency, and an increase in AC loss tan δ, which lowers the Q of the circuit and causes a sudden change in the output.

Therefore, changes in oil quality can be easily measured and displayed with extremely high sensitivity as changes in electrical resistance or AC impedance.

Next, specific examples of the present invention will be described.

FIG. 1 shows the basic measurement circuit of the invention. The oil quality measuring device is composed of a measuring electrode 4 consisting of a pair of opposing electrodes 1, 1', a DC, AC or high frequency constant voltage power source 5, and an ammeter 6.

The oil 2 to be measured is placed between the measuring electrodes 4 of the measuring device configured as described above. When the purity of the oil is high and the amount of conductive particles such as carbon, metal powder, and impurities is small, the specific resistance value is high and almost no current I flows.

Furthermore, when the oil deteriorates and impurities increase, the impurities become charged like an ionic current and move between the electrodes, causing a current to flow. At this time, by reading the value on the ammeter 6, the deterioration of the oil can be determined qualitatively. Furthermore, a decrease in viscosity can also be measured as an increase in current using equation (5).

FIG. 2 shows another embodiment of the invention.

This embodiment is applied to a bridge circuit, and a bridge is constructed by impedance elements 7, 7, measurement electrodes 4, and impedance 8 corresponding to oil, and an ammeter 6 and a direct current, alternating current, or high frequency low voltage. It consists of a power supply 5. Further, in the case of this embodiment, it is also possible to add a temperature correction input to the impedance 8 corresponding to oil, or to add an automatic zero balance circuit.

With the above configuration, deterioration in oil quality can be measured by the ammeter 6 as a change in the resistance value of the measurement electrode 4 or alternating current impedance. Therefore, accuracy can be improved compared to the case of direct measurement as in the first embodiment.

FIG. 3 shows a third embodiment of the invention. The measuring device is
It is composed of a measurement electrode 4, a coil 10, an oscillation circuit active element section 11, a tuning circuit section 12, a detection circuit section 13, an input synthesis circuit 14, and a display section 15. The capacitance change C of the measurement electrode 4 constitutes a part of the oscillation circuit together with the coil 10, and is oscillated by the oscillation circuit active element 11. The oscillation output is input to the tuning circuit 12 and tuned, detected by the detection circuit 13, judged by the input synthesis circuit 14, and then displayed on the display section 15.

In the case of the above configuration, the capacitance C between the measurement electrodes is
is used as part of an oscillation circuit, its oscillation output is tuned and detected, and by measuring the output, the increase in conductive particles can be captured and measured as a change in capacitance, that is, a change in frequency and an increase in AC loss tanδ. I can do it. Further, according to this embodiment, changes in oil quality can be measured and displayed with particularly high sensitivity. FIG. 4 shows an example of a coaxial structure so that it can be inserted through the oil gauge hole.

The measuring device includes a center electrode 19 within a cylindrical external electrode 20, and an insulating part 17 that has the same diameter and is continuous with the external electrode 20.
It is divided by an insulating end oil seal portion 18. Further, the center electrode 19 and the outer electrode 20 are connected by a detection lead wire 16.

In the case of the above structure, since it has a coaxial structure, it can be inserted through the oil gauge hole, and the influence of surrounding metal parts can be avoided due to the shielding effect. Therefore, accurate values can be obtained. Furthermore, if these outputs are made into an OR circuit that operates in parallel with the output of a conventional oil pressure sensor, it is possible to constantly monitor the oil pressure drop caused by a decrease in the amount of oil, contamination of the oil cleaner, etc.

FIG. 5 shows a case where a measuring electrode is provided on a part of the dropper. Suction conduit 21 of dropper 21. Electrodes are placed facing each other at both ends of a and drawn out by lead wires 22.

In the case of the above configuration, it is possible to use the measuring electrode of the integrated suction conduit 21a to measure the oil that is sucked and measured as a sample through use at a gas station, service factory, etc. Both tables are convenient and easy to use.

Figure 6 (al, (bl, cl, (dl) shows an example in which electrodes are installed on an oil filter and an air cleaner. The front and back sides of the filter surface of the filter 22 (d
The measuring electrodes 23 are provided at regular intervals (b) and (c).

In the above cases, it is possible to directly detect clogging of the oil filter or air filter due to contamination. Furthermore, the position of the measurement electrode is not limited to the above embodiments, and may be located in the middle of the oil pulp piping.

〔Effect of the invention〕

According to the oil quality measuring device of the present invention configured as described above, the deterioration number of oil quality can be displayed very qualitatively, so that oil quality control can be easily and simply measured. Therefore, it is possible to easily know the appropriate time to change the engine oil, which facilitates engine maintenance and extends the life of the engine.It also prevents unnecessary early oil changes and makes effective use of resources. can.

Furthermore, the present invention is not limited to measuring engine oil, but can be applied to measuring the quality of other liquids such as gear box oil and transformer oil.

[Brief explanation of the drawing]

Fig. 1 is a circuit diagram showing one embodiment of the present invention, Fig. 2 is a circuit diagram showing another embodiment of the invention, and Fig. 3 is a circuit diagram showing a third embodiment of the invention.
4 is a block diagram showing the fourth embodiment of the present invention. FIG. 5 is a block diagram showing the fifth embodiment of the present invention. FIG. 6 is a circuit diagram showing the fifth embodiment of the present invention. (C1, (d) is a configuration diagram showing a sixth embodiment of the present invention. 1.1°...electrode, 2...oil, 4...measuring electrode, 5...constant Voltage power source Miro...Ammeter, 7
... Impedance element, 8... Corresponding impedance. 9... Variable element sensor human power section, 10... Coil, 11... Oscillation circuit active element section, 12... Tuning circuit section, 13... Detection circuit section, 14... Input synthesis circuit, 15...Display section, 16...Detection lead wire, 17
...Insulation part, 18...Oil seal part, 19.
... Center electrode, 20... External electrode, 21... Dropper, 22... Filter, 23... Measurement electrode. Patent Applicant Koji Ando Representative Patent Attorney Yoshiyuki Osuga Figure 1 Figure 3

Claims (6)

[Claims] (1) A measuring device that measures quality changes in liquid substances such as oil by capturing them as changes in direct current resistance, alternating current, or high frequency impedance. (2) A coaxial electrode consisting of a center electrode and an outer electrode that can be inserted through an oil gauge hole, an insulated end oil seal part, an insulated part, and a detection lead wire. oil quality measuring device (3) A patent characterized in that it is composed of a measurement electrode, a constant voltage power supply section, an ammeter or display section, a bridge detection circuit configuration impedance element, and a human power section for impedance corresponding to the measurement electrode and a variable element sensor such as temperature. Oil quality measuring device according to claim 1 (4) A patent claim comprising a measurement electrode, an impedance constituting an oscillation circuit, an oscillation circuit active element section, a similar circuit section, a detection circuit section, an input synthesis circuit, a display section, and an input terminal. Oil quality measuring device described in scope 1 (5) The oil quality measuring device according to claim 1, characterized in that measurement electrodes are provided facing each other at both ends of the suction conduit of the dropper. (6) The oil quality measuring device according to claim 1, characterized in that measurement electrodes are provided at both ends of the filter surface of the oil filter or air cleaner or at regular intervals.