JPS63123638A - Filter device of electric discharge machine - Google Patents

Abstract

PURPOSE:To shorten repeated service time of a filter device and enhance the filtrating function by sensing eventual drop of the filtrating function, applying compressed air to the output side of the filtrating member, and thereby shaking off sludge attached to the input side. CONSTITUTION:When clog of a filtrating member 5 causes emission of a sensing signal DS from a rate-of-flow sensor 15 to allow a control device 13 to judge that the amount of processing liquid collected to a tank 12 has decreased below the reference level, control signals C1, C2 shut solenoid valves 14, 17, while control signals C3. C4 open solenoid valves 20, 23. Compressed air from a compressed fluid source 21 is supplied to a bottom chamber 2b, and sludge 22 attached to the top chamber 2a of the abovementioned filtrating member 5 is dropped to eliminate clogging, and now the compressed air intruded into the top chamber 2a through the filtrating member 5 is released to the atmosphere from a pipe 19. This action is restituted after an implementation for a certain while, and filtration of the processing liquid is performed again in good performance.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a filter device for an electrical discharge machine. (Prior Art) Since machining fluid for electrical discharge machines is used repeatedly, a filter device is used to separate machining debris, sludge, etc. from the used machining fluid. Conventional filter devices for electrical discharge machines used for this purpose have a cloth filter installed near the bottom of the filter tank, and the machining fluid to be filtered is injected into the upper chamber of the cloth filter, and the injected machining fluid is By applying pressurized air to the machining fluid, sludge is left on the cloth filter, and the machining fluid filtered by the cloth filter is returned to a service tank or the like.

(Problem that is intended to be solved) In general, the capacity of the filter tank is 70 to 100
(j) However, in the case of the above-mentioned filter device, for example, if 40 (Plmln) is processed, the filtering ability will be lost in about 2 hours, and the processing inside the filter device in such a state will be It takes 24 to 72 hours to filter the liquid through a cloth filter as described above. This is because in conventional filter devices, air pressure is applied to the sludge that has settled on the cloth filter installed at the bottom of the tank, so relatively large chips accumulate in the lower layer, but the upper layer This is because extremely fine chips form a tyrocholate-like film and cover the area, allowing the machining fluid to pass through and K<.

With conventional filter equipment, the sludge drying process takes several tens of hours, which significantly reduces the operating efficiency of the filter equipment, resulting in increased equipment costs such as the need for multiple filter equipment. The problem is that it has no choice but to increase.

Therefore, an object of the present invention is to shorten the sludge drying time, to remove sludge from used processing fluid with high efficiency, and to significantly shorten the time required for the drying process of sludge, etc. An object of the present invention is to provide a small-sized filter device for an electric discharge machine that can perform the following functions.

(Means for Solving the Problems) The filter device for an electric discharge machine according to the present invention is characterized by having a tank that is divided into an upper chamber and a lower chamber by a filtering member, and the processing water supplied to the upper chamber. In the filter device for an electrical discharge machine, the impurities in the machining fluid to be processed are filtered by the filtering member and sent to the lower chamber, and the filter device includes a pressurized air source and pressurized air from the pressurized air source to the upper chamber. a supply passage means for supplying the supply to the chamber, a first supply solenoid valve provided in the supply passage means, a release solenoid valve for releasing the pressure in the upper chamber to atmospheric pressure, and communicating with the lower chamber. a discharge passage provided in the discharge passage, a discharge solenoid valve provided in the discharge passage, a pressurized fluid source, and a pressurized fluid passage for guiding pressurized fluid from the pressurized fluid source to the lower chamber. means, a second supply electromagnetic valve provided in the pressurized fluid passage means, means for outputting a command signal for instructing the start of filtration by the filter device, and an amount of processed liquid filtered by the filtration member. a detection means for outputting a detection signal related to the above; and a detection means that responds to the command signal and the detection signal to open the first supply solenoid valve and the discharge solenoid valve when the amount of the machining fluid exceeds a predetermined amount; The second supply solenoid valve and the open solenoid valve are closed. If the amount of the machining fluid is less than the predetermined amount, the first supply solenoid valve and the discharge solenoid valve are closed for a predetermined time, and the second supply solenoid valve and the discharge solenoid valve are closed. and control means for controlling each electromagnetic valve to open the open electromagnetic valve.

(Function) When the filtration member is not clogged, the flow rate of the filtered liquid detected by the detection means per unit time is large, and therefore the first supply solenoid valve is opened. Since the electromagnetic valve is closed, pressurized air from the pressurized air source is applied to the processing fluid to be filtered in the upper chamber, and the processing fluid filtered by the filter member flows into the lower chamber. At this time, since the second supply solenoid valve is closed and the drain discharge solenoid valve is opened, the filtered machining liquid is taken out through the discharge passage.

When the detection means detects that the filtering member has become clogged tb due to the fact that the machining fluid is filtered in this way and the flow rate of the filtered machining fluid has become less than a predetermined amount, the first supply solenoid valve is closed, the opening solenoid valve is opened, and the pressure that has been applied to the upper chamber is released. At the same time, the exhaust solenoid valve is closed and the second supply solenoid valve is opened to allow pressurized fluid from the source of pressurized fluid to flow into the lower chamber, through the filter member, and into the upper chamber. This state lasts for a predetermined amount of time,
As a result, chips and the like attached to the filter member are removed, and the clogging state is eliminated.

Therefore, when each electromagnetic valve returns to its state for filtering again, the processing fluid can be filtered satisfactorily.

By doing so, the clogging of the filter member is appropriately eliminated, and the processing liquid can be filtered in a short time.

(Example) Hereinafter, the present invention will be explained in detail with reference to the illustrated embodiments.

FIG. 1 shows an embodiment of a filter device for an electric discharge machine according to the present invention. This filter device 1 is for filtering used machining fluid containing water or oil as a base, and separating and extracting sludge and the like mixed in the used machining fluid from the machining fluid. A filter tank 2 is provided.

In the illustrated embodiment, the filter tank 2 is composed of a substantially cylindrical upper tank 3 whose lower end is open, and a lower tank 4 provided at the lower end of the upper tank 3. A filtering member 5 is provided inside the upper tank 3 so as to cover the lower end opening 3a of the upper tank 3. The inside of the filter tank 2 is divided by the filter member 5 into an upper chamber 21 and a lower chamber 2b.

As shown in FIG. 2, the filter member 5 is made up of a stainless steel mesh 6 and a filter cloth 7 disposed inside the upper tank 3.
Impurities in the used machining fluid are separated from the machining fluid by the filter cloth 7, and the filtered machining fluid passes through the stainless steel net 6 and enters the lower chamber 2a.

At the upper end of the upper tank 2, there is provided an injection port 8 for injecting the used processing liquid to be filtered into the upper chamber 2a. By opening the valve 9, the used machining fluid can be injected into the upper chamber 21 from here. The used machining fluid 16 injected into the upper chamber 2& is filtered by the above-mentioned filtering member 5, and the filtered machining fluid is collected in the lower chamber 2b, and then transferred to the take-out pipe 1 provided at the lower end of the lower tank 40.
1 to the service tank 12.

A first solenoid valve 14 which is controlled to open and close in response to a first control signal cl from a control device 13, which will be described later, is connected to the takeout/4 eve 11, and a service tank 1 is connected to the eject/4 eve 11.
A flow rate detector 15 is provided for detecting the flow rate per unit time of the filtered machining fluid supplied to the flow rate detector 2 .

The flow rate detector 15 outputs a detection signal D indicating the detected flow rate.
B is output and input to the control device 13.

A pressurized air source 16 is provided to apply pressure for filtration to the processing fluid to be filtered injected into the upper chamber 2aK, and the pressurized air source 16 is provided with a second electromagnetic valve 17. It communicates with the vicinity of the upper end of the upper tank 2 through the I4 Eve 18. The second solenoid valve 17 is controlled to open and close in response to a second control signal C, given from the control device 13, and when the second solenoid valve 17 is opened, pressurized air from the pressurized air source 16 is supplied to the Noyaigu 18. The used machining fluid is introduced into the upper chamber 2a through the upper chamber 2a, and the used machining fluid injected into the upper chamber 2a is pressurized.

/4 Ig 19 installed near the upper end of the upper tank 2
has one end open to the atmosphere, and when the third solenoid valve 20, which is controlled to open and close in response to the third control signal Cs output from the control device 13, is opened, the pressure in the upper chamber 2a increases. is made equal to atmospheric pressure.

Reference numeral 21 indicates a pressurized fluid source in which pressurized air, which is a pressurized fluid, is stored to apply pressure to the lower chamber 2b to remove the sludge 22 adhering to the filter member 5. The pressurized fluid source 21 includes a fourth solenoid valve 23 and is connected to the outlet pipe 24 by a ninth arm 24. Opening/closing is controlled in response to signal C4.

Next, the functions of the control device 130 will be explained.

After injecting the processing liquid to be filtered into the upper chamber 2a from the injection port 8 and closing the manual on-off valve 9, the switch 25 is closed to give a command signal indicating the start of filtration to the control device 13. 13 starts operating. First, the first and second solenoid valves 14 are activated by the first and second control signals 01sC1.
,172>! while the third and fourth control signals C5
At tC4, the third and fourth solenoid valves 20.23 are closed. Therefore, pressurized air from the pressurized air source 16 acts on the machining fluid in the upper chamber 2a, and the machining fluid in the upper chamber 21 is pressed toward the filter member 5. The machining fluid filtered by the filtering member 5 is collected into the service tank 12 via the extraction/retrieval system, and the flow rate of the machining fluid collected into the service tank 12 is detected by the flow rate detector 15. The detection signal DB indicating the result is sent to the control device 13.
is input.

When the control device 13 determines based on the detection signal 08 that the amount of machining fluid collected into the service tank 12 by the filtering member 50 has decreased to a predetermined reference amount or less, the first and second The two solenoid valves 14.17 receive the first and second control signals C1#c.

while the third and fourth solenoid valves are closed respectively by the third and fourth solenoid valves.
and fourth control signal C3*C4] respectively. As a result, pressurized air from the pressurized fluid source 21 is supplied to the lower chamber 2bK, and the sludge 22 adhering to the upper chamber 2a side of the filtration member 5 is dropped from the filtration member 5, and Blindness is eliminated. The pressurized air that has entered the upper chamber 2a via the filter member 5 is discharged into the atmosphere via the noib 19.6 The above-mentioned operation for dropping the sludge 22 is performed for a predetermined period of time, for example, and then the operation is performed again. It is returned to operation for filtering the processing fluid. As a result, the machining fluid can be successfully filtered again.

The above-mentioned control functions of the control device 13 include microcontrollers, -
The control program is configured to be executed by causing a computer (not shown) to execute a predetermined control program, and FIG. 3 shows a flowchart showing the control program. Next, the 70-chart will be explained.

After starting the program, initialization is performed in Stella'f31, and in step 32 it is determined whether the switch 25 is on. If the switch 25 is off, the determination result is NO, step 3
2 is executed repeatedly.

When the switch 25 is turned on, the determination result in step 32 is YF3, and the process proceeds to step 33, where the first and second solenoid valves 14.17 are opened, and the third and fourth solenoid valves 20 are opened.
．． 23 is executed. This is the first to fourth
Control signal C! This is performed by C4K.

Thereafter, it is determined in step 34 whether or not the flow rate F of the machining fluid detected based on the detection signal DB is greater than a predetermined reference flow rate A. If the determination result is YES, the Stellar 7''35 The process proceeds to step 33, where it is determined once again whether the switch 25 is on, and if the switch 25 is on, the process returns to step 33 to maintain the current control state.If the switch 25 is off, , return to step 32] and wait for the switch 25 to be turned on again.

If F≦A occurs due to the filter member 5 being clogged, etc., the determination result in step 34 is NO, and the first and second solenoid valves 1
4.17 is closed, and the third and fourth solenoid valves 20.23 are opened (Stella f36). Next, a timer is started in Stella f37, and determination as to whether or not the timer value T has reached a predetermined value BK is executed in Stella 7'38. When T≧B, the determination result in step 38 is YES.
The process then proceeds to step 39, where it is determined whether the switch 25 is on.

If the switch 25 is on, return to step 33;
The first and second solenoid valves 14.17 are opened and the third and fourth solenoid valves 14.17 are opened.
The solenoid valves 20, 23 are closed, and the processing fluid filtration operation is thereby started again. If the switch 25 is off, the process returns to step 32 and waits for the switch 25 to be turned on again.

According to the above-described configuration, when it is detected that the filtration amount of the machining fluid filtered by the filter device 1 has become less than a predetermined value, pressurized air is applied from the output side of the filter member 5 for a predetermined period of time, and the filtration is performed. Since it is configured to remove the sludge 22 adhering to the member 5, the sludge can be dehydrated in a shorter time than in the past, and the operating rate of the filter device can be increased. As a result, it is possible to achieve the same filtration effect as the conventional filter device with a filter device having a smaller capacity than the conventional filter device.

(Effects of the Invention) According to the present invention, as described above, when the filtration capacity of the filter device decreases, this is detected, pressurized air is applied to the output side of the filtration member, and the sludge attached to the input side is removed. Since the structure is such that the filter device can be used repeatedly, the time required for repeated use of the filter device can be shortened, and the filtering function can be significantly improved. Therefore, if the filtration function is the same, the filter device can be downsized, and a high-performance filter device that can be operated automatically can be provided.

[Brief explanation of the drawing]

FIG. 1 is a schematic configuration diagram showing one embodiment of a filter device according to the present invention, FIG. 2 is a perspective view showing the structure of the filter member shown in FIG. 1, and FIG. 3 is a flowchart showing a control program to be executed. 1... Filter device, 2... Filter tank, 2m
...Upper mold, 2b...Lower chamber, 5...Filtering member,
10... Processing fluid, 11... Take-out glossy tube, 13.
... Control device, 14... First solenoid valve, 15... Flow rate detector, 17-... Second solenoid valve, 20... Third solenoid valve, 21... Pressurized fluid source, 23 ...Fourth solenoid valve. Patent applicant Sodick Co., Ltd. Agent Patent attorney Masatoshi Takano Figure 1 1 Filter device Figure 3

Claims (1)

[Claims] 1. The tank is divided into a tenth chamber and a second chamber by a filtration member, and the impurities in the processing fluid to be treated that is supplied to the first chamber are filtered by the filtration member. A filter device for an electric discharge machine configured to supply pressurized air to a second chamber, a pressurized air source, a supply passage means for supplying pressurized air from the pressurized air source to the first chamber, and the supply passage means for supplying pressurized air from the pressurized air source to the first chamber; a first supply solenoid valve provided in the passage means; a release solenoid valve for releasing the pressure in the first chamber to atmospheric pressure; a discharge passage communicating with the second chamber; a discharge solenoid valve provided in the passage, a pressurized fluid source, pressurized fluid passage means for guiding pressurized fluid from the pressurized fluid source to the second chamber, and the pressurized fluid a second supply solenoid valve provided in the passage means; a means for outputting a command signal for instructing the filter device to start filtration; and a detection signal related to the amount of processing liquid filtered by the filter member. a detection means, in response to the command signal and the detection signal, opens the first supply solenoid valve and the discharge solenoid valve and opens the second supply solenoid valve and the discharge solenoid valve when the amount of processing fluid is equal to or greater than a predetermined amount; closes the solenoid valve and closes the first supply solenoid valve and the discharge solenoid valve and opens the second supply solenoid valve and the opening solenoid valve for a predetermined time when the amount of the machining fluid is less than the predetermined amount. A filter device for an electrical discharge machine, comprising a control means for controlling a solenoid valve.