JPS59166840A - Viscosity detector - Google Patents

Abstract

PURPOSE:To always monitor the deterioration state of an oil and to indicate clearly the exchanging time of the oil basing on the quantitative value by monitoring the oscillating frequency of a tuning fork dipped in the oil. CONSTITUTION:The tuning fork 9 of a sensor part is dipped in the oil 2, and a piezoelectric element 10 attached to the tuning fork is connected to an oscillation circuit 5 by a connecting cable 13. The oscillating frequency at this time is determined by the tuning fork, but is varied depending on the viscosity of the material surrounding the tuning fork. Next the output of the circuit 5 is inputted to a mixing circuit 7. The output of a reference frequency generating circuit 6 is inputted to the circuit 7, these two inputs are compared and the difference is outputted to an alarm circuit 8. At this time, the signal from a temp. sensor 4 is inputted to the circuit 6, and the reference frequency corrected by the oil temp. is sent out to the circuit 7. If the data from the mixing circuit grow up more than the reference value, the circuit 8 send out the alarm to an alarm sending- out terminal 14.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a viscosity detector installed in a machine having an oil tank to detect the entire viscosity of oil.

Conventionally, the deterioration state of the oil in machine tools and automatic motors was checked by visual inspection or periodically checked by Vc155, and the oil was not replaced based on quantitative values. For this reason, there were problems such as shortening the service life of machines, etc. by replacing them even though they were in a fully usable state, or by using them in a deteriorated state.◎ The present invention solves the above-mentioned conventional problems. The object of the present invention is to provide a viscosity detector that constantly monitors the deterioration state of oil and indicates when to replace the oil based on quantitative values.

The present invention includes a sensor section having a piezoelectric element installed in an oil tank, an oscillation circuit electrically connected to the sensor section, and electrically insulated from the oil and the oil tank;
A viscosity detector comprising a reference frequency generating circuit, a mixing circuit having one input of the output of the oscillation circuit and the other input of the reference frequency generating circuit, and an alarm circuit having the output of the frequency determination circuit as input. .

The present invention utilizes the fact that, in an oscillation circuit using a piezoelectric element, the oscillation frequency changes depending on the viscosity of the substance in which the vibrating body having the piezoelectric element is immersed.

Next, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram of an embodiment according to the present invention. 1st
In the figure, 1 is an oil tank, 2 is oil, 3 is a sensor unit for piezoelectric element, 4 is a temperature sensor, 5 is an oscillation circuit,
6 is a reference station V number generation circuit, 7 is a mixing circuit, 8 is an alarm circuit, and 14 is an alarm sending terminal. Figure 2 shows one row of sensor parts, where 9 is a tuning fork and 10 is a row of sensors.
indicates a piezoelectric element, and 11 and 12 indicate electrodes. FIG. 3 shows a complete cross-sectional view of the oil tank equipped with the sensor section, and as in FIG. 1, 1 is the oil tank, 2 is oil, 3 is the sensor section,
Reference numeral 13 indicates a connection cable.The operation will be explained using the following diagram. As shown in FIGS. 41 and 3, the tone tip 9 of the sensor section is immersed in oil 2, and the pressure and electric element IO attached to this tone tip is connected to the oscillation circuit 5 by a connecting cable 13. The oscillation frequency at this time is determined by the tuning fork, but it is a well-known fact that it changes depending on the viscosity of the material around which the tuning fork is wound.The output of the oscillation circuit 5 is input to the mixing circuit 7. . Further, the output of the reference frequency generation circuit 6 is inputted to the mixing circuit 7, and the two inputs are compared and the difference is outputted to the mixing circuit 8. At this time, a signal from the temperature sensor 4 is input to the reference frequency generating circuit 6, and a reference frequency corrected for the oil temperature is sent to the reference frequency generating circuit 7. 8 sends an alarm to the all alarm sending terminal 14 when the data from the mixing circuit becomes larger than the reference value. At this time, by controlling the transmission of the sea alarm by the output from the temperature sensor, it is possible to prevent the transmission of an alarm due to a decrease in viscosity during low-temperature operation.

As explained above, by detecting the difference between the oscillation frequency of the tuning fork oscillator circuit when the oil has not deteriorated and the oscillation frequency when the oil has deteriorated and its viscosity has increased, Changes in viscosity can be detected 0 For example, in the case of engine oil for automobiles, there are many types of oil, but for engines, the deterioration of viscosity is a guideline for conversion, and this means that the oscillation frequency of the Shinsa-type oscillation circuit It is all about reading changes in By monitoring the oscillation frequency 't of the tuning fork immersed in oil in this manner, it is possible to quantitatively determine the oil conversion timing.

Although such a circuit can be constructed using individual ICs, etc., a small viscosity detector with good axiality can be constructed even more easily by using a microcomputer or the like.

As explained above, the present invention makes it possible to quantitatively grasp the oil change timing by monitoring the frequency of the oscillation circuit that uses all of the pressure IL elements, and to inform the outside of the oil change period. This is extremely effective in preventing machine wear and tear due to oil wastage or delayed oil replacement.

[Brief explanation of drawings]

Fig. 1 is a circuit block diagram of one embodiment of the present invention, Fig. 2 is an external view of the sensor section-embodiment that uses the piezoelectric element shown in Fig. 1, and Fig. 3 is the sensor shown in Fig. 2. A cross-sectional view of the part installed in the oil tank is shown. l...Oil tank, 2...Oil,
3...Sensor part that shoulders the piezoelectric element, 4...
...Temperature sensor, 5...Oscillation circuit, 6...
...Reference frequency generation circuit, 7...Mixing circuit, 8...Alarm circuit, 9...Tone fork, 10...Piezoelectric element, 11 and 12・・・・・・
...Electrode, 13...Connection cable, 14...
...Alarm sending terminal. Second evil

Claims (1)

[Claims] A sensor unit having a pressure regulator installed in an oil tank, an oscillation circuit electrically connected to the sensor unit and electrically insulated from the oil tank and oil, a reference frequency generation circuit, and the oscillation circuit. A viscosity detector comprising a mixing circuit whose output sound is one input and the output of the reference frequency generating circuit as the other input, and an alarm circuit whose input is the output of the plate mixing circuit.