JPH0551419U - Filtration device - Google Patents

Abstract

(57) [Abstract] [Purpose] A filtration device that uses the piezoelectric effect of electrostrictive substances, has a self-cleaning effect that causes the filter to vibrate in a vibrating circuit and eliminates clogging by itself, and that can be used for a long time. provide. A filter 1 having a part or all of a filter block having open-cell-shaped pores formed of an electrostrictive substance incorporated therein, and the filter 1 is vibrated by utilizing the piezoelectric effect of the electrostrictive substance. A vibration circuit 2, a pump 5 for pumping the unfiltered liquid R to the filter 1, a pressure sensor 4 provided in a pumping path from the pump 5 to the filter 1, and a value of the pressure sensor 4 is compared with a reference value. And a determination circuit 3 for turning on and off the vibration circuit 2.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a filtering device used for a circulating fluid reusing device such as a machine tool or a washing machine, which removes impurities from the circulating liquid.

[0002]

[Prior Art]

 In general, it is desirable to keep the circulating fluid cleanliness level as high as possible in the above recycling apparatus. This is because the pollutants in the circulating fluid cause damage, malfunctions, malfunctions, and shorten the service life of machine tools and other equipment. Therefore, a filter is installed in the circuit of the recycler to remove impurities that do not dissolve in the circulating fluid. However, when this filter gradually becomes clogged and the suction resistance increases, it is necessary to immediately replace it with a new one or a cleaned one.

[0003]

[Problems to be solved by the device]

 Therefore, if an increase in the discharge pressure of the pump that circulates the liquid or a decrease in the discharge flow rate is detected beyond a certain amount, the reuse device must be stopped and the filter replaced. For machines that require continuous operation, the filter circuits should be arranged in parallel, and when one of the filters is used, the other should be closed and this filter should be replaced when it is time to replace the filter in use. Close the circuit. At the same time, by opening the other circuit, it is possible to replace the old filter without stopping the operation of the reuse device. However, in any case, since the filter is clogged quickly and the interval between replacements is short, it is troublesome that the operator must constantly monitor the discharge pressure and flow rate of the pump. ing.

The present invention has been made in view of the above problems of the conventional technique. The purpose of the present invention is to utilize the piezoelectric effect of an electrostrictive substance to filter a filter in an exciting circuit. The purpose is to provide a filtration device that has a self-cleaning effect of vibrating and self-clearing clogging and can be used for a long time.

[0005]

[Means for Solving the Problems]

 In order to achieve the above object, the filtering device of the present invention comprises a filter in which a filter block having open-celled pores formed of an electrostrictive substance is partially or entirely incorporated, and A vibrating circuit that vibrates the filter using the piezoelectric effect, a pump that pumps unfiltered liquid to the filter, a pressure sensor provided in the pumping path from the pump to the filter, and the value of the pressure sensor as a reference value. And a judgment circuit for turning on / off the vibration circuit.

[0006]

[Action]

 When the filter becomes clogged and the pressure of the unfiltrated liquid exceeds a certain value, the vibration circuit operates to vibrate the filter and eliminate the clogging.

[0007]

【Example】

 Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a diagram showing a system of a filtering device of the present invention.

In FIG. 1, 11 is a machine tool, 12 is a tank built in the machine tool 11 for storing the circulating liquid 13, and 10 is provided in the middle of a suction pipe 14 and a discharge pipe 15 for circulating the circulating liquid 13. It is a filtering device. The filtering device 10 includes an electrostrictive filter 1 that vibrates by operating the vibration circuit 2, a controller 3 that is a judgment circuit for judging the timing of turning the vibration circuit 2 ON and OFF, and the unfiltered liquid R. It comprises a pressure sensor 4 for measuring the pressure, a pump 5 for pumping the circulating liquid 13 to the filter 1, and a filtration tank 7. The controller 3 may be, for example, a microcomputer.

The operation of the filtration device 10 having the above-described configuration will be described below. A part of the circulating liquid 13 is sent to the pressure feed pump 5 from the tank 12 of the machine tool 11 through the suction pipe 14. The pressure pump 5 pressure-feeds the circulating liquid 13, which is the unfiltered liquid R, from the inlet 6 of the filtration tank 7 to the filter 1. Then, the circulating liquid 13 is freed of impurities by the filter 1, flows in the direction of the arrow 8, reaches the discharge pipe 15 from the discharge port 9 and returns to the circulating liquid tank 12. As the filtration progresses, the clogging of the filter 1 becomes worse, so that the flow of the circulating liquid 13 becomes worse and the value of the pressure in the pressure feeding path from the pressure feeding pump 5 to the filter 1 becomes larger. The pressure sensor 4 detects the change in the pressure value and transmits it to the controller 3, and the vibration circuit is appropriately turned on and off to eliminate the filter clogging.

Next, the operation of the controller 3 will be described with reference to FIG. When the pressure value exceeds the A value at point a1 with the passage of time of operation of the machine using this filter, the vibrating circuit 2 is switched on according to the judgment of the controller 3, and the filter 1 is vibrated. Then, the impurities clogged in the eyes of the filter 1 are separated from the surface of the filter 1 and the like so that the circulating liquid 13 can pass through again smoothly, so that the pressure value in the pressure feeding path becomes small. Therefore, when the pressure value b1 falls below the B value at point b, the vibration circuit 2 is switched off according to the judgment of the controller 3, and the vibration of the filter 1 is stopped. Then, as the time passes, the pressure value reaches the A value at the point a2, so the controller 3 turns on the vibration circuit 2 to vibrate the filter 1 to eliminate the clogging, and at the point b2, the filter 1 Stop the vibration of. In this way, the filter 1 has a self-cleaning function of vibrating by itself when clogging occurs and removing impurities by separating impurities from the filter surface.

In the determination circuit described above, the vibration time t (b−a) of the filter 1 required for clearing the clogging gradually becomes longer as the usage time of the filter 1 elapses, and finally, it can be removed only by the vibration of the filter. Since a large amount of impurities are accumulated in the pressure-feeding path from the pressure-feeding pump 5 to the filter 1, the C-value does not drop further and approaches a C value, and the vibration continues forever like t6. By monitoring the vibration time t of the filter 1 required for clearing the clogging and issuing an alarm, the replacement time of the filter 1 can be known. Therefore, if you want to use machine tools continuously, check the clogging of the filter 1 beforehand so that the flow of the circulating fluid will not get worse and the filter 1 will not be replaced in a hurry. Further, when the impurities shaken off from the filter 1 accumulate in the lower portion of the tank, the drain 16 can be released to discharge the impurities.

Further, the controller 3 may be a circuit for making a judgment as shown in FIG. That is, when the pressure value exceeds the A value at the point a1, the vibration circuit 2 is switched ON according to the judgment of the controller 3, and the filter 1 is vibrated. This vibration is performed for a certain time T to eliminate the clogging. Next, even when the pressure value reaches the A value at the point a2, the filter 1 is vibrated for a certain time T. Then, when the filter 1 starts to vibrate continuously, replace the filter 1. Further, the operation interval (T1 to T5) of the vibration circuit 2 can be monitored, and the filter 1 can be replaced when a certain time or more has passed.

Next, a filter using the piezoelectric effect of the electrostrictive substance used in the above-described filtering device will be described with reference to FIGS. 4 and 5. An electrostrictive filter (Japanese Patent Laid-Open No. 2-290210) previously proposed by the present inventor is used as a filter for generating mechanical vibration (piezoelectric vibration). This filter is proposed with the aim of reducing the filtration resistance to the circulating fluid (constant vibration) or increasing the efficiency of filter cleaning (single vibration). However, it has not been considered and practically used as an example of a filtration device for circulating fluid that is prone to clogging, such as water-soluble cutting oil of machine tools, which has a self-cleaning action during operation. ..

4 and 5 show a filter in which a filter block formed of an electrostrictive material is incorporated in a part or the whole thereof. The filter block 52 is a plate-shaped electrostrictive material in which open-cell-shaped holes 51 are formed. On both sides of the filter block 52, holes such as a wire mesh, a perforated metal plate, and a ring conductor are formed. The electrostrictive filter 101 of FIG. 4 is formed by tightly adhering the electrodes 53, 53 together. The fluid to be filtered is filtered through the electrodes 53 and 53 of the electrostrictive filter A and the holes of the filter block 52. When an AC voltage is applied to both electrodes 53 and 53, the piezoelectricity of the filter block 52 causes electrostriction. The filter 101, as an electrostrictive oscillator, generates mechanical vibration (piezoelectric vibration). In addition, the three types of electrostrictive filters 102, 103, and 104 in FIG. 5 are filter blocks 52 of electrostrictive substances, and a filter 59 that is not an electrostrictive substance is provided inside (electrostrictive filter 102) and on both sides (electrostrictive filter 102). 103), when it is built in the inner surface (electrostrictive filter 104) and an AC voltage is applied to both electrodes 53, 53 as in the electrostrictive filter 101, the electrostrictive filters 102, 103, 104 are also electrostrictive due to the piezoelectricity of the filter block 52. The oscillator generates mechanical vibration (piezoelectric vibration).

[0015]

[Effect of the device]

 When the filter becomes clogged, it vibrates itself and shakes off impurities, so the clogging is automatically eliminated and the filter can be used continuously for a long time, so the interval between filter replacements becomes longer. In the past, if the filter became clogged and the circulating fluid flow deteriorated, the machine using the circulating fluid had to be stopped and the filter replaced immediately at that point. With this filtration device, the degree of contamination of the filter can be known in advance based on changes in the pressure of the unfiltrated liquid, etc., and there is no need to worry about sudden stoppage of the circulating liquid for filter replacement, etc. Can be used.

[Brief description of drawings]

FIG. 1 is a view showing a system of a filtering device of the present invention.

FIG. 2 is a graph showing the operation of the controller of the filtering device of the present invention.

FIG. 3 is a graph showing another operation of the controller of the filtering device of the present invention.

FIG. 4 is a sectional view of an electrostrictive filter.

FIG. 5 is a sectional view of an electrostrictive filter.

[Explanation of symbols]

 1 Electrostrictive Filter 2 Vibration Circuit 3 Controller (Judgment Circuit) 4 Pressure Sensor 5 Pressure Feed Pump 10 Filtration Device

Claims (1)

[Scope of utility model registration request] 1. A filter in which a filter block having open-celled pores made of an electrostrictive substance is incorporated in a part or all of the filter block, and the filter is vibrated by utilizing the piezoelectric effect of the electrostrictive substance. A vibrating circuit, a pump for pumping unfiltrated liquid to the filter, a pressure sensor provided in a pumping route from the pump to the filter, and the value of the pressure sensor is compared with a reference value to turn the vibrating circuit on and off. A filtering device consisting of a judgment circuit.