JPH03121725A - Electric discharge machining liquid supplying device - Google Patents

Abstract

PURPOSE:To prevent damage of a pump for discharge machining liquid by furnishing as a control means to control the amount of machining liquid supplied from a clean liquid trough to a processing trough in accordance with the liquid amount sensed by a liquid amount sensing means provided in the clean liquid trough, and thereby preventing the clean liquid trough from being emptied. CONSTITUTION:Because the poured quantity of discharge machining liquid as required is 'L2' in case the plate thickness of a work is large like a work 18b, clean liquid in a clean liquid trough 1 is supplied to a processing liquid 3. When the poured quantity attains the max. liquid amount LA, the liquid amount in the clean liquid trough 1 decreases to a specified level to actuate a liquid amount sensing device 8, and a pump changeover device 9 is operated to stop a discharge machining liquid pump 7 while start another discharge machining liquid pump 6. From the poured quantity LA of the machining liquid to the poured quantity L2, consequently, the clean liquid in the trough 1 is supplied to the processing trough 3 only by means of the pump 6. At this time, the contaminated liquid from a contaminated liquid trough 2 is passed through a filter 5 by a pump 4 for purifying and is supplied to the clean liquid trough 1.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to an improvement in a machining fluid supply device that can quickly fill a machining tank with machining fluid when performing immersion machining with an electric discharge machine. be.

[Prior Art] A conventional immersion type electric discharge machine performs electric discharge machining by filling a machining tank in which electric discharge machining is performed with machining fluid. On this occasion,
Since it takes a considerable amount of time to fill the machining tank with the machining fluid, a device is required to rapidly supply the machining fluid to the machining tank in order to shorten the time.

Figure 8 shows a machining fluid supply device for a conventional electrical discharge machine that has a function of rapidly supplying machining fluid to a machining tank. In the figure, (1) is a clean fluid tank, and (2) is a dirty fluid tank, (3) is a processing tank, (5) is a processing liquid filter that removes processing sludge etc. from the waste liquid and turns it into a clear liquid, (4) is a processing liquid filter (5) that transfers the waste liquid from the waste liquid tank (2) to the processing liquid filter (5). Processing fluid pump Pi for feeding and supplying clear fluid to the clear fluid tank (1), (8) is the clear fluid tank (1)
Processing liquid pump P that supplies clear liquid between the poles of the processing tank (3)
2. (7) transfers the processing liquid (clean liquid and dirty liquid) to the processing tank (3)
This is a machining fluid pump P3 for rapidly filling the fluid.

Next, the operation will be explained. Clear liquid tank (1) during electrical discharge machining
The fresh machining fluid inside is supplied to the machining gap of the machining tank (3) by the machining fluid pump P2 (8), and electrical discharge machining is performed. The sewage from the machining fluid contaminated by electrical discharge machining is transferred to the sewage tank (2).
The machining liquid pump Pi (4) and the machining liquid filter (5) clear the liquid and return it to the clean liquid tank (1).

At that time, machining fluid pump PL (4) and machining fluid pump P2 (
6) ability is Pi > P2 (approximately 10 [1/m
1n: ]), and the fresh liquid processing liquid is in the clear liquid tank (about 1n:]).
) and flows into the waste tank (2) where it is circulated.

Next, the operation of rapidly filling the machining tank (3) with machining fluid will be explained. In the machining fluid supply device shown in Fig. 8, when a command is issued to rapidly fill the machining fluid (clean fluid) into the machining tank (3), the machining fluid pump P3 (7) operates to fill the machining fluid (clear fluid) into the machining tank (3).
The fresh liquid processing liquid in the fresh liquid tank (1) is rapidly supplied to the liquid tank (1). At this time, the flow rate of the machining fluid is 200 to 300 [1/m1n
1, and even if the machining fluid is circulated by the machining fluid pump P L (4) and the machining fluid pump P2 (6) as described above, the fresh machining fluid in the fresh fluid tank (1) will rapidly Therefore, if the capacity of the fresh liquid tank (1) is not greater than the capacity of the processing tank (3), the fresh liquid tank (1) will be empty before the processing liquid (clean liquid) fills the processing tank (3). As a result, the machining liquid pump P3 may idle and become unable to function as a pump (the pump sucks in air, reducing pump performance), or the pump may malfunction. To avoid this, go to the fresh liquid tank (1).
It is necessary to increase the capacity of the fresh liquid tank (1) so that the fresh liquid inside does not run out. Also, if the capacity of the sewage tank (2) itself is not larger than the capacity of the processing tank (3), the sewage will become contaminated when the processing fluid filled in the processing tank (3) is collected into the sewage tank (2). The liquid will overflow from the tank (2).

In addition, as shown in Fig. 9, if the processing tank (3) is rapidly filled with processing liquid using the sewage from the sewage tank (2), the capacity of the sewage tank (2) can be made sufficient. If you increase it to
There is no need to worry about running out of the fresh machining fluid in the fresh fluid tank (1), the machining fluid can be rapidly supplied to the machining tank (3), and the machining fluid supply device can be made relatively small. I can do it.

[Problems to be Solved by the Invention] Since the machining fluid supply device of the conventional electric discharge machine is configured as described above, the machining fluid supply device shown in FIG. It needs to be larger than the machining fluid capacity of the tank, and the entire machining fluid supply device becomes large, requiring a large installation space and increasing costs. Also the 9th
In the machining fluid supply device shown in the figure, waste fluid is used as the machining fluid that fills the machining tank, so the machining fluid supply device can be relatively small, but it has a significant negative impact on machining performance such as machining accuracy and machining speed. will give.

The present invention has been made in order to solve the above-mentioned problems of conventional devices, and it is possible to downsize the machining fluid supply device of an electrical discharge machine, reduce the installation space, and prevent the machining fluid pump from deteriorating in pump function or malfunctioning. The purpose is to provide an inexpensive machining fluid supply device that does not have any adverse effects or impair machining performance.

[Means for Solving the Problems] As a means for achieving the above object, a machining fluid supply device for an electric discharge machine according to the present invention includes a fluid amount detecting means disposed in a clear fluid tank, and the detecting means. and a control means for controlling the amount of machining liquid supplied from the clear liquid tank to the machining tank in accordance with the liquid amount detected by.

In addition, as another means for achieving the above purpose, the flow rate of the liquid feeding device that feeds the machining liquid in the dirty liquid tank to the clean liquid tank via the filtration device is made variable, and the machining liquid in the clean liquid tank is processed. When rapidly filling the tank, the amount of processing liquid supplied from the dirty liquid tank to the clean liquid tank is
It is configured so that the amount of processing liquid in the clear liquid tank is not less than the amount supplied to the processing tank.

[Function] Since the machining liquid supply device is configured as described above, the amount of machining liquid in the clean liquid tank will not always become smaller than the predetermined liquid amount, even without increasing the size of the clean liquid tank or the dirty liquid tank. Of course, the liquid tank will never be empty. Therefore, the machining fluid pump will not malfunction.

[Embodiment of the Invention] Figure 1 is a block diagram of a machining fluid supply device showing an embodiment of the present invention, in which (1) to (7) are the same or equivalent parts as in the conventional device, and (8) is the same as or equivalent to the conventional device. The liquid volume detector (9) detects the fresh liquid in the fresh liquid tank (1), and the machining liquid pump P3 (7) and the machining liquid pump P2 (8) according to the detected value of the liquid level detector (8). This is a pump switching device that switches between. In addition, Fig. 2 is a configuration diagram showing the filling state of machining fluid in the machining tank, and (18a)
, (18b) is the workpiece.

Next, the operation will be explained. During electrical discharge machining, the fresh machining fluid in the fresh fluid tank (1) is supplied to the machining tank (3) by the machining fluid pump P2 (8), similar to the machining fluid supply device of a conventional electrical discharge machine.
), and electrical discharge machining is performed. The dirty machining fluid contaminated by electrical discharge machining is collected in the dirty fluid tank (2), purified by the machining fluid pump PL (4) and the machining fluid filter (5), and returned to the clean fluid tank (1). It will be done. At that time, the machining fluid pump PL (4) and the machining fluid pump P
The capacity of 2(6) is PI>P2 (processing fluid supply amount is approximately 10
[1/min] degree), and the clear liquid processing liquid is in the clear liquid tank (1/min).
) overflows and flows into the waste tank (2) where it is circulated.

Next, the operation of rapidly filling the machining tank (3) with machining fluid will be explained. In the figure, the processing tank (3) is connected to the clear liquid tank (
When a command to rapidly fill the fresh liquid machining liquid in step 1) is issued, the machining liquid pump p3 (7) starts and rapidly fills the fresh liquid machining liquid in the fresh liquid tank (1) into the machining tank (3). supply to. At this time, the flow rate of the machining fluid is 200 to 3ΩOEl/ll1in], and even though the machining fluid is circulated by the machining fluid pump P1 (4) and the machining fluid P2 (6) as described above,
The fresh liquid processing liquid in the fresh liquid tank (1) decreases rapidly. However, the amount of fresh processing liquid in the fresh liquid tank (1) is determined by the liquid level detection device (8).
When the fluid volume falls below a predetermined fluid volume (the machining fluid suction port of machining fluid pump P3 is set to a high position), the pump switching device (9) will function and switch to a higher fluid flow rate. Since the machining liquid pump P3 (7) is stopped and the machining liquid pump P2 (8) is activated, the fresh liquid tank is pumped into the machining tank (3) without reducing the amount of fresh liquid in the clear liquid tank (1). (1)
The supply of internal liquid processing liquid continues, and finally the processing tank (3
) is filled with clear liquid processing liquid. In addition, in Figure 2, (
18a) is a workpiece having a thickness of Hl (approximately 50 to 100m111), and most of the workpieces usually have this thickness, and the amount of processing liquid required to process this workpiece (18a) is Ll. In addition, (18b) is a workpiece having a thickness of H2 (approximately 250 to 300mm), which corresponds to the maximum processing thickness, and the processing tank (
The filling amount of machining fluid in 3) is L2.

Furthermore, LA is processed! (3) is the maximum amount of liquid that can rapidly supply machining fluid to P3 (7).
Accordingly, the fresh liquid in the fresh liquid tank (1) can be rapidly supplied. At this time, even if the machining liquid filling amount reaches Ll, the fresh liquid in the clear liquid tank does not reduce to the predetermined liquid level, so the switching device (9) does not operate, and the fresh liquid is smoothly supplied to the processing tank (3). And it happens quickly.

However, when the thickness of the workpiece is large like the workpiece (18b), the required filling amount of machining fluid is L2 as described above, so the clear liquid in the clear liquid tank (1) is poured into the machining tank (3). supply,
When the machining fluid filling amount in the machining tank (3) reaches LA, the fluid amount in the clean fluid tank (1) decreases to a predetermined fluid amount, so the fluid amount detection device (8) functions and the pump switching device (9) is activated, and the machining fluid pump P3 (7) is stopped and the machining fluid pump P
Start 2. As a result, from the machining fluid filling amount LA to the machining fluid filling amount L2, the fresh machining fluid in the fresh fluid tank (1) is supplied to the machining tank (3) only by the machining fluid pump P2 (8).

At that time, the processing liquid pump Pi (4)
The waste processing liquid from 2) is passed through a processing liquid filter (5) to become clear liquid and is supplied to the clear liquid tank (1).
>P2, the fresh processing liquid in the clear liquid tank (1) does not decrease below the amount detected by the liquid level detection device and reaches the processing tank (
3) Processing fluid filling is completed. In other words, the operation of filling and supplying machining fluid into the machining tank (3) is performed rapidly (machining fluid supply amount 20
0 to 300[1/ω1nl), and from machining fluid filling amount LA to completion of machining fluid filling amount L2, machining fluid pump P2 (6) slowly (10 [1 nl) in terms of machining fluid supply amount. /m1nl) is carried out.

In the above embodiment, the machining fluid pump P3 and the machining fluid pump P2 are used as means for supplying the clear machining fluid to the machining tank (3), and both pumps are connected to the pump switching device (9).
), it is configured to switch and supply the
As shown in Fig. 3, the output of the machining liquid pump P3 (7) is made variable using an inverter (10), and the fresh liquid is processed into the machining tank (3) based on the detection signal of the liquid level detector (8). The amount of liquid supplied may be controlled. Further, although not shown, the same effect can be obtained by using one machining fluid pump instead of the machining fluid pump P2 (6) and machining fluid pump P3 (7) and using them separately.

Furthermore, as shown in Fig. 4, the output of the machining fluid pump P3 (7) is kept constant, and an on-off valve (12) is installed in the piping for rapidly filling the machining fluid sent out from the machining fluid pump P3 (7).
A bypass pipe is installed in which the fresh processing liquid is collected in the fresh liquid tank (1), and the opening/closing valve is operated by the valve opening/closing device (11) based on the detection signal of the liquid amount detecting device (8). (12) may be operated to adjust the amount of fresh processing liquid supplied to the processing tank (3).

Based on the same concept, as shown in Fig. 5, processing fluid pump P3 (7
) is kept constant, and a variable flow rate valve (14) is installed in the piping for rapidly filling the machining fluid sent from the machining fluid pump P3 (7), and the variable flow rate valve is adjusted by the detection signal of the fluid volume detection device (8). The variable flow rate valve (14) may be operated by the device (13) to adjust the amount of fresh processing liquid supplied to the processing tank (3).

Furthermore, FIG. 6 shows another embodiment based on a different idea, in which (15) is a processing fluid pump P4, and (16) is a pump switching device. In normal processing, the sewage tank (2
Processing liquid pump Pi (
4), but when a command is given to rapidly fill the processing tank (3) with the clear liquid in the clear liquid tank (1), the processing liquid pump P3
(7) operates and transfers the liquid in the liquid tank (1) to the processing tank (1).
At the same time, the pump switching device (1B) functions to switch the processing liquid pump to P, which sends the sewage from the sewage tank to the clean liquid tank (1).
Pump L(4) is switched to pump P4(15), which has a larger liquid feeding amount. As a result, the amount of machining fluid supplied from the dirty fluid tank (2) to the clean fluid tank (1) increases, and the amount is increased by the machining fluid pump P.
3 (7), the amount of machining liquid rapidly supplied from the clear liquid tank (1) to the machining tank (3) is controlled to be greater than or equal to the amount.
The amount of liquid in the fresh liquid tank (1) does not decrease.

In the above embodiment, a pump switching device (16) is used to switch between the machining fluid pump PL (4) and the machining fluid pump P4 (15) as a means for supplying the fresh machining fluid to the fresh fluid tank (1).
In this example, an inverter (1
7) may be used to make the output of the machining liquid pump PL (4) variable to adjust the amount of fresh machining liquid supplied to the fresh liquid tank (1).

〔Effect of the invention〕

As described above, the present invention provides an electrical discharge machine having a function of rapidly filling the machining fluid in the fresh fluid tank into the machining fluid tank, in which the machining fluid supply device is connected to a liquid amount detecting means in the fresh fluid tank; A control means for controlling the amount of processing liquid supplied from the clear liquid tank to the processing tank according to the amount of liquid detected by the detection means. In addition, the flow rate of the liquid feeding device that feeds the machining fluid in the sewage tank to the clean fluid tank is made variable, so that when the machining fluid in the clean fluid tank rapidly fills the machining tank, the flow rate from the sewage tank to the clean fluid tank is changed. Since the system was configured so that the amount of machining liquid supplied from the clear liquid tank was not less than the amount of machining liquid supplied to the machining tank, the following excellent effects could be achieved.

(1) Since the machining fluid in the fresh liquid tank never becomes empty, the machining fluid pump will not be damaged.

(2) The fresh liquid tank and dirty liquid tank can be made smaller.
The installation space for the machining fluid supply device is also reduced, making it possible to reduce costs.

[Brief explanation of drawings]

Fig. 1 is a block diagram of a machining fluid supply device which is an embodiment of the present invention, Fig. 2 is a diagram showing the filling state of machining fluid in the machining tank depending on the thickness of the workpiece, and Figs. 5, 6, and 7 are block diagrams showing other embodiments of the present invention, and FIGS. 8 and 9 are block diagrams of a conventional machining fluid supply device for an electrical discharge machine. In the figure, (1) is a fresh liquid tank, (2) is a dirty liquid tank, (3) is a processing tank, (4) is a processing liquid pump PI, (5) is a filter, and (6) is a processing tank.
) is machining fluid pump P2, (7) is machining fluid pump P3, (
8) is a liquid level detection device, (9) is a pump switching device, (10)
) is the inverter, (11) is the valve opening/closing device, (I2)
(13) is the valve adjustment device, (14) is the variable flow rate valve, (15) is the processing fluid pump P4, (1B
) is the pump switching device, (17) is the inverter, <18a
) and (18b) are the workpieces. Note that the same reference numerals in the figures indicate the same or equivalent parts. Figure 2: Machining liquid is rapidly charged Figure 1: Machining area is rapidly refilled Figure 3: Processing source z1! Charging Figure 6 Figure 7 Processing counterfeit sudden complete vortex

Claims (2)

[Claims] (1) A machining tank for performing electrical discharge machining, a sewage tank for storing the sewage discharged from the sewage tank, and a filtration device for filtering the sewage in the sewage tank to make it clear. , a wave transmitting device for sending the dirty liquid in the dirty liquid tank into the clean liquid tank through the filtration device, a clean liquid tank for storing the fresh liquid filtered by the filtration device, and the clean liquid tank. It has a liquid feeding device for feeding the fresh liquid in the liquid tank to the processing tank, and a rapid wave sending device to rapidly feed the fresh liquid in the liquid tank to the processing tank as necessary. A machining fluid supply device for an electric discharge machine comprising: a fluid amount detection means for detecting the amount of machining fluid in the fresh fluid tank; 1. A machining fluid supply device for an electrical discharge machine, comprising a control means for controlling the amount of machining fluid supplied to the machining tank. (2) A machining tank for performing electrical discharge machining, a sewage tank for storing the sewage discharged from the sewage tank, and a filtration device that filters the sewage in the sewage tank to make it clear. , a wave transmitting device for sending the dirty liquid in the dirty liquid tank into the clean liquid tank through the filtration device, a clean liquid tank for storing the fresh liquid filtered by the filtration device, and the clean liquid tank. It has a liquid feeding device for feeding the fresh liquid in the liquid tank to the processing tank, and a processing liquid supply device for rapidly feeding the fresh liquid in the clear liquid tank to the processing tank as necessary. The machining fluid supply device for the electric discharge machine is configured such that the wave transmitting device for feeding the dirty fluid in the dirty fluid tank to the clean fluid tank via the filtration device is configured to have a variable flow rate. A machining fluid supply device for an electric discharge machine, characterized in that the amount of machining fluid supplied to the fresh liquid tank is not less than the amount of machining fluid supplied from the fresh liquid tank to the machining tank.