JPH04141320A - Work liquid feeding device for electric discharging machine - Google Patents

Abstract

PURPOSE:To maintain the highly accurate work of an electric discharging machine, and to enable an unmanned operation for a long time, by controlling the specific resistance value of a replenished work liquid so as to become the same value as the specific resistance value controlled by a specific resistance detection device by a specific resistance control unit. CONSTITUTION:A work liquid fed to a machine main body 10 by a pump 9 from a clean liquid tank 2 is returned to a dirty liquid tank 1 together with work chips, but the quantity of the work liquid returned to the dirty liquid tank 1 is being reduced by the evaporation, splash, etc. When the reduction of this liquid quantity is detected by a liquid level detector 14, a feed water means 15 replenishes the work liquid into the dirty liquid tank 1, via a specific resistance control unit 17 from a work liquid feeding source 13, further via a 2nd specific resistance detection device 16. When the liquid level detector 14 detects that the work liquid quantity inside the dirty liquid tank 1 reaches a constant quantity, the feed water means 15 stops the liquid replenishment. In the case of the specific resistance value controlled by the 1st specific resistance detection device 5 of the clean liquid tank 2 side being high and the specific resistance value of the work liquid feeding source 13 being low, at the replenishing time of the work liquid, the control unit 17 controls the specific resistance of the replenishing liquid in the same value as the value controlled by the detection device 5.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a machining fluid supply device for an electrical discharge machine.

[Prior Art] FIG. 2 is a block diagram showing a machining fluid circuit of a conventional machining fluid supply device for an electric discharge machine. In the figure, (1) is the dirty liquid tank, (2) is the clean liquid tank, (3) is the filter installed in the clean liquid tank (2), and (4) is the processing liquid in the dirty liquid tank (1). filter(
(3) is a first pump for supplying the liquid into the clear liquid tank (2), (5) is a specific resistance detection device for machining liquid provided in the clear liquid tank (2), and (6) is a first pump for supplying the clear liquid into the clear liquid tank (2). ) is a deionizer for adjusting the specific resistance of the machining fluid in the tank (7) is a second pump for supplying the machining fluid in the clear fluid tank (2) to the deionizer (6);
8) is based on the detection result of the resistivity detection device (5).
A control device that controls the pump (7), (9) a third pump for supplying the machining liquid in the clear liquid tank (2) with adjusted specific resistance to the machine body (10), and (11) a control device that controls the pump (7); Sewage tank (1)
Float that detects the amount of machining fluid in (12) is flow 1
- This is a valve for automatically replenishing machining fluid into the tη liquid tank (1) from a machining fluid supply source (13) such as tap water based on the detection result of (II).

In such a device, the machining waste in the machining fluid in the sewage tank (1) is removed from the machining fluid in the sewage tank (1) by the first pump (4).
is fed to the filter (3) and removed by filtration. The processing liquid filtered by the filter (3) is stored in the clear liquid tank (2);
In order to use the machining fluid in 2) for high-precision machining, it is necessary to further adjust the resistivity of the machining fluid. To control the resistivity of the machining fluid, the control device (8) starts and stops the second pump (7) based on the signal detected by the resistivity detection device (5), and the water is processed into the pure water device (6). This is done by supplying liquid. The machining fluid whose specific resistance has been controlled is supplied to the machine body (9) by the third pump (9) and contributes to electrical discharge machining.

The machining fluid supplied to the machine body (10) is returned to the sewage tank (1) together with machining waste, but contamination may occur due to evaporation due to heat generated during machining in the machining section or scattering of the machining fluid. The amount of the two liquids returned to the liquid tank (1) decreases. Therefore, conventionally the float (11) and valve (12)
Accordingly, tap water or the like is automatically replenished directly from the machining fluid supply source (13) into the sewage tank (1) to compensate for the decrease in machining fluid.

[Problems to be Solved by the Invention] Since the conventional machining fluid supply device for an electrical discharge machine is configured as described above, the specific resistance value of the machining fluid in high-precision machining is, for example, 100,000 yen for carbide materials. Although it is set to Ω or more,
As the machining fluid decreases during machining, it must be directly replenished with tap water, which usually has a specific resistance value of around 10,000 Ω.
Processing fluid whose specific resistance is not controlled by 4IQ is mixed in the processing fluid supply device, and the pure water device (6) is installed in the clear fluid tank (2).
Although the specific resistance of the machining fluid is adjusted by the pure water device (6), during continuous operation, machining fluid other than the set resistivity value reaches the machine body (J).
As a result, the discharge gap between the electrode for electrical discharge machining and the workpiece changes, which leads to a problem in that machining accuracy deteriorates.

In addition, such problems become a strong obstacle when constructing a machining fluid supply system to realize long-term continuous unmanned operation of electric discharge machines in high-precision machining, and they also cause problems when electric discharge machines are wire electric discharge machines. In some cases, this may cause the wire electrode to break, which may interrupt processing.

In view of the above points, the present invention has been developed so that even when the machining fluid decreases,
The object of the present invention is to obtain a machining fluid Cj (feeding device) for an electric discharge machine that can maintain high precision machining without interrupting machining and realize long-term continuous unmanned operation of the electric discharge machine.

[Means for Solving the Problems] A machining fluid supply device for an electric discharge machine according to the present invention includes a clean fluid tank that stores machining fluid to be supplied to the machine body, and a dirty fluid tank that collects the machining fluid from the machine body. A tank, a liquid level detector for detecting the amount of machining liquid in the sewage tank, and a water supply means for replenishing the machining liquid from a machining liquid supply source into the sewage tank based on the detection result of the liquid level detector. , a first pump for feeding the machining fluid in the dirty fluid tank to the clean fluid tank via the filter, and a first ratio for detecting the specific resistance of the machining fluid in the clean fluid tank. a resistance detection device, a pure water device for adjusting the specific resistance of the machining liquid in the fresh liquid tank, and a second pump for feeding the machining liquid in the fresh liquid tank to the pure water device. , a control device that controls the second pump based on the detection result of the first resistivity detection device, and a second resistivity detection device that detects the resistivity of the machining fluid replenished by the water supply means. , the resistivity of the machining fluid replenished from the water supply means is controlled based on the resistivity value detected by the second resistivity detector and the resistivity value controlled by the first resistivity detector. It is equipped with a resistivity control device.

[Function] In the present invention, the specific resistance control device controls the specific resistance value of the machining fluid to be replenished to be the same value as the specific resistance value controlled by the first specific resistance detection device, and To prevent machining fluids with different values from mixing in the machining fluid supply device.

[Embodiment] Hereinafter, the present invention will be explained with reference to an embodiment shown in FIG. 1, in which parts corresponding to conventional ones are denoted by the same reference numerals.

FIG. 1 is a block diagram showing the machining fluid circuit of the machining fluid supply device for an electrical discharge machine according to this embodiment. Surface detector, (1
5) is a water supply means (16) for automatically replenishing machining fluid from a machining fluid supply source (13) such as water supply into the sewage tank (1) based on the detection result of the fluid level detector (14); ) is connected to the waste liquid tank (1) from the processing liquid supply source (13) via the water supply means (15).
), the second resistivity detector (17) detects the resistivity of the machining fluid replenished into the tank (2), and (17) is the resistivity value obtained by the second resistivity detector (1B) and that of the clear liquid tank (2). The machining fluid is replenished from the machining fluid supply source (13) via the water supply means (15) based on the resistivity vegetation controlled by the resistivity detection device (hereinafter referred to as the first resistivity detection device) (5). This is a resistivity control device that controls the resistivity of the device, and when the resistivity value obtained by the second resistivity detector (1G) and the resistivity value controlled by the first resistivity detector (5) are different. , a first resistivity detection device (5) detects the resistivity of the machining fluid replenished from the machining fluid supply source (13).
The specific resistance value is controlled to be the same as the specific resistance value controlled by .

Since the configuration other than the above is the same as the conventional one, the explanation thereof will be omitted.

In the apparatus of this embodiment configured as described above, the third pump (9) moves the main body (lO
) The processing fluid supplied to the waste tank (1) together with processing waste is
However, due to evaporation due to the heat generated during processing in the processing section, or scattering of processing fluid,
) The amount of machining fluid returned to ) decreases. When the liquid level detector (14) detects this decrease in the amount of machining liquid, the water supply means (
15) passes the machining fluid from the machining fluid supply source (13) to the resistivity control device (17), and further to the second resistivity detection device (16).
), the sewage tank (1) is automatically replenished. When the liquid level detector (I4) detects that the amount of machining liquid in the waste liquid tank (1) has reached a certain level due to the replenished machining liquid, the water supply means (
15) stops replenishment of machining fluid.

When replenishing the machining fluid, the resistivity value controlled by the first resistivity detection device (5) on the clear fluid tank (2) side is high (for example, 100,000Ω).
), when the machining fluid supply source (13) has a low resistivity value (approximately 20,000Ω), such as water supply, the second resistivity detection device (16)
Since the specific resistance value obtained in 1 and the specific resistance value controlled by the first specific resistance detection device (5) are different, the specific resistance control device (17) detects the machining fluid replenished from the machining fluid supply source (13). The specific resistance is controlled to be the same value as the specific resistance value controlled by the first specific resistance detection device (5).

In this way, in the device of this embodiment, the resistivity value of the machining fluid to be replenished is always the set resistivity value, so machining fluids with different resistivity values do not coexist in the machining fluid supply device. Therefore, the discharge gap between the electric discharge machining electrode and the workpiece is stabilized even during continuous unattended operation for long periods of time, making it possible to maintain high precision machining.

It goes without saying that the present invention can be applied to various machining devices that use a machining fluid mainly composed of water, such as a wire electrical discharge machining device, an inviscid die-sinking electrical discharge machining device, and an electrolytic machining device.

[Effects of the Invention] As described above, according to the present invention, the specific resistance value of the machining fluid to be replenished can always be set to the set resistivity value, so even when the machining fluid decreases, machining can be continued. This has the effect that high-precision machining can be maintained without interruption, and it is also possible to realize long-term continuous unmanned operation of the electrical discharge machine.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing a machining fluid circuit of a machining fluid supply device for an electric discharge machine according to this embodiment, and FIG. 2 is a diagram showing a machining fluid circuit of a conventional machining fluid supply device for an electric discharge machine. It is. In the figure, (1) is the dirty liquid tank, (2) is the clean liquid tank, and (3)
is the filter, (4) is the first pump, (5) is the first resistivity detection device, (6) is the pure water device, (7) is the second pump, (8) is the control device, (10 ) is the machine body, (13)
(14) is a liquid level detector, (15) is a water supply means, and (1B) is a second resistivity detection device. In each figure, the same reference numerals indicate the same or equivalent parts.

Claims (1)

[Claims] A clean liquid tank that stores the machining liquid supplied to the machine body, a dirty liquid tank that collects the machining liquid from the machine body, a liquid level detector that detects the amount of machining liquid in this dirty liquid tank, and a liquid level detector that detects the amount of machining liquid in this dirty liquid tank. water supply means for replenishing the machining fluid from the machining fluid supply source into the sewage tank based on the detection result of the surface detector; and for feeding the machining fluid in the sewage tank to the clear fluid tank via the filter. a first pump, a first resistivity detection device for detecting the resistivity of the machining fluid in the fresh fluid tank, and a pure water device for adjusting the resistivity of the machining fluid in the fresh fluid tank; , a second pump for feeding the machining liquid in the fresh liquid tank to the pure water device, and a control device that controls the second pump based on the detection result of the first resistivity detection device. and a second resistivity detection device that detects the resistivity of the machining fluid replenished by the water supply means, and a resistivity value detected by the second resistivity detection device and a resistivity value that is controlled by the first resistivity detection device. and a resistivity control device for controlling the resistivity of the machining fluid replenished from the water supply means based on the resistivity value of the machining fluid for an electrical discharge machine.