JPH01140919A - Electric discharge machine - Google Patents

Abstract

PURPOSE:To prevent working environment from being deteriorated by providing a device with a feed pump feeding working fluid to interpole gaps from a working fluid tank, an aspirator to which working fluid is fed by an another feed pump, and with a connecting pipe provided to the interpole gaps via both the sucking section of said aspirator and an electrode. CONSTITUTION:When specified voltage is applied between an electrode 2 and a work piece 9, electric discharge is induced between them. Working fluid 7 in a working fluid tank 12 is fed to a working drum 6 by a feed pump 11, and working fluid 7 overflowing is returned to the working fluid tank 12 by way of a drain hose 14. On the other hand, when working fluid 7 is fed to an aspirator 15 by an aspirator pump 17, suction force is produced so as to let the inside of an insulating hose 16 be negative in pressure. When electric discharge machining is processed under this condition, gas, smoke and chips deriviated by machining are sucked into the aspirator 15 together with working fluid 7 by way of the electrode 2, an adapter 3 and the insulating hose 16 so as to be mixed with working fluid in the working fluid tank 12, thereby letting gas and smoke be hardly evaporated into air.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to electrical discharge machining equipment, and particularly to a machining fluid suction device thereof.

[Conventional technology]

A machining fluid is interposed between the opposing electrodes and the workpiece,
Machining using a large-area graphite electrode is performed in an electrical discharge machining device that applies a machining voltage higher than the dielectric breakdown voltage between the electrode and the workpiece to generate electrical discharge machining between the electrodes, and performs machining using this discharge energy. In general, machining is performed while spouting machining fluid from the electrode itself, but because the current used for machining is large, there is a lot of gas and smoke generated from the machining area, and there is also a strong odor, so some operations may be difficult. Environmental improvements were required. Conventionally, the method of installing an exhaust fan and exhausting the generated gas and smoke outside was used, but because the suction port is far from the processing area, it may not be effective enough, or it may not be possible to obtain a smoke exhaust effect. This required the installation of large-capacity exhaust fans, which posed an economical problem.

[Problem that the invention seeks to solve]

On the other hand, in recent years, the conventional method of spouting machining fluid from the electrode has been replaced by a method that sucks the machining fluid from the electrode itself, and at the same time sucks in the gas and smoke generated during machining. Although this method has been sufficiently effective in suppressing the generation of gas and smoke, it requires a large capacity air compressor because compressed air is used to generate the suction force of the suction device. That is, there was an economical problem due to the high cost (2I) When generating suction force with compressed air, noise was generated and the work environment was deteriorated.

This invention was made for the purpose of improving the problem of gas generated by electrical discharge machining.

This paper attempts to propose an electrical discharge machining device equipped with a suction device that is effective in exhausting smoke, is inexpensive, and does not degrade the working environment due to noise.

[Means for solving problems]

This invention relates to electrical discharge machining in which a machining liquid is interposed in a gap between an electrode and a workpiece facing each other, and a machining voltage is applied between the electrode and the workpiece to generate an electric discharge in the gap between the electrodes. In the device, the machining fluid is supplied from the machining fluid tank by a fluid supply pump that supplies the machining fluid in the machining fluid tank to the gap between the poles, and a fluid supply pump that is provided separately from this pump. The device is equipped with an aspirator that generates suction force, and a connecting tube whose one end is connected to the suction portion of the aspirator and whose other end faces the gap between the electrodes via the electrode.

[For production]

In this invention, the aspirator generates a suction force when the machining fluid is supplied, sucks gas, smoke, etc. generated in the gap between the poles through the connecting pipe, and transfers them together with the machining fluid into the machining fluid tank. Send it in.

〔Example〕

An embodiment of the present invention will be described below with reference to the drawings.

The figure is a configuration diagram of an electric discharge machining apparatus according to the present invention. In the figure, 11) is a head for processing and feeding the electrode (2);
3) is an adapter for attaching the electrode (2) to the head Il+, (4) is a column supporting the head +11,
Head (held by 51. (61 is machining fluid (7)
A processing tank that stores water, and a table (8
). (9) is a workpiece fixed to the table (8), and 0 is a saddle that can move the workpiece (9) back and forth. on is the liquid supply pump installed in the machining liquid tank +13, and the machining tank (61
is connected to. [14 is the drain hose. tts is an aspirator connected to the adapter (3) by an insulating hose αe. αD is the aspirator liquid supply pump and hose Ql.

It is connected to aspirator α9 via α9 and valve ■. The ring is a filter that filters the processing liquid (7).
It is installed on the discharge side of the liquid supply pump αυ.

Note that a passage (not shown) is formed in the electrode (2) and the adapter (3) themselves to introduce gas and smoke generated by discharge, and this passage communicates with the insulating hose αe.

Next, the operation will be explained.

First, when a predetermined voltage is applied between the electrode (2) and the workpiece (91), an electric discharge is generated in the opposing gap between the electrode (21) and the workpiece (9).

Then, the machining fluid (7) in the machining fluid tank α2 is sent to the machining tank (6), and the overflowing machining fluid (7) is sent to the machining fluid tank az via the drain hose [141]. return. On the other hand, aspirator liquid supply pump o
When the machining fluid (7) is sent to the aspirator α9 by n, a suction force is generated and the inside of the insulating hose αυ becomes negative pressure.

In this state, the electrode (2) is fed for processing.

When the workpiece (91) is subjected to electric discharge machining, the gas and smoke generated by machining, as well as the machining chips, are transferred together with the machining fluid (7) to the electrode (2), adapter C3), and insulating hose αe.
It is sucked into the aspirator α9 via the .

Therefore, the generated gas and smoke rarely escape into the air.

Incidentally, the suction force can be adjusted by adjusting the opening degree of valve (2) to increase or decrease the amount of machining fluid (7) supplied from the aspirator fluid supply pump αη.

Generally, the suction capacity of the aspirator α should be set to 50 t/min or more.

In addition, if the hose αe that communicates the aspirator tiS and the electrode (2) is made of an insulating material as in the embodiment, the electrode (2)
) and the workpiece (9), which is preferable since it does not have any adverse effect on the electrical discharge between the workpiece (9) and the workpiece (9).

In the above embodiment, the aspirator αS is connected to the machining fluid tank a.
Although it was installed in 'a', it may be installed on the machine side such as the processing tank (6) or the bed (5) in order to reduce the line resistance of the insulating hose cui.

〔Effect of the invention〕

As described above, according to the present invention, a new dedicated aspirator fluid supply pump is provided, which is separate from the pump that supplies machining fluid to the machining section, and the machining fluid is pressurized and supplied to the aspirator to generate suction force. compared to conventional equipment that uses compressed air.

It is possible to secure a large suction force or suction amount without generating noise, and compared to conventional equipment that uses an exhaust fan, the suction part is the machining part itself, that is, the electrode itself in the machining fluid. You can significantly improve your abilities.

In addition, this device also sucks up the generated machining chips (sludge) at the same time, so the machining chips are not interposed between the machining holes, which prevents secondary discharge and increases machining stability, improving machining speed. It also has the advantage that the processing liquid in the processing tank is always kept in a clear state because the processed chips do not diverge into the processing tank. As described above, the present invention can exhibit an extremely large effect of significantly improving the working environment at a low cost.

[Brief explanation of the drawing]

The figure is a configuration diagram of an electrical discharge machining apparatus according to an embodiment of the present invention. In the figure, (11 is the head 8, (2) is the electrode, (31 is the adapter, (4) is the column, (5) is the bed, (6) is the machining tank, (7) is the machining fluid, and (8) is the table. , (9) is the workpiece, ari is the saddle, aυ is the liquid supply pump, +
13 is the machining fluid tank, σ3 is the hose, aa is the drain hose, and a9 is the aspirator. αe is insulated hose (connection pipe), (Iη is aspirator liquid supply pump, (I19.09 is hose, ■ is pulp, c
2υ is a filter.

Claims (3)

[Claims] (1) Electrical discharge machining in which a machining fluid is interposed in the gap between the electrodes and the workpiece, and a machining voltage is applied between the electrode and the workpiece to generate an electric discharge in the gap between the electrodes. In the device, the machining fluid is supplied from the machining fluid tank by a fluid supply pump that supplies the machining fluid in the machining fluid tank to the gap between the poles, and a fluid supply pump that is provided separately from this pump. an aspirator that generates suction;
An electrical discharge machining device comprising a connecting pipe having one end connected to the suction part of the aspirator and the other end facing the inter-electrode gap through the electrode; (2) The electric discharge machining apparatus according to claim 1, wherein the aspirator has a suction capacity set to 50 l/min or more. (3) The electric discharge machining apparatus according to claim 1, wherein the connecting pipe is made of an electrically insulating material.