JPH0197527A - Machining liquid cooling method for wire electric discharge machine - Google Patents

Abstract

PURPOSE:To cool machining liquid through simple structure, by a method wherein an air bubble generator having a number of pores is disposed to the bottom part of a machining liquid storage tank, and an infinite number of air bubbles are discharged in the machining liquid. CONSTITUTION:Contaminated and heated machining liquid flows from a machining tank 1 to a contaminated liquid tank 3, where relatively large machining chips are settled. Supernatant is forced to flow through a filter 7 with the air of a pump 5, fine machining chips are removed, and the supernatant is fed to a clean liquid tank 9 for storage. An air bubble generator 11 is located to the bottom part of the clean liquid tank 9, through the feed of compressed air through an air feed port 15, air bubbles 13 are generated through a number of pores, and machining liquid is cooled by means of an infinite number of the air bubbles 13. Thereafter, The machining liquid is injected through upper and lower nozzles 19 and 21 in a machining tank 1 toward a discharge gap with the aid of a machining liquid feed pump 17. This method enables cooling of the machining liquid through the air bubble generator having simple structure.

Description

[Detailed Description of the Invention] [Object of the Invention] (Industrial Application Field) The present invention relates to a method for cooling machining fluid of a wire electrical discharge machine.

(Prior Art) In a wire electric discharge machine, water is normally used as a machining fluid. The role of this processing liquid (water) is as follows.

(1) Squeeze the discharge column and increase the current density at the discharge point. (2) Cool the molten material removed by machining and make it solid, increasing the removal efficiency of machining debris. (3) Insulate the discharge gap early. Recovery (4) Decomposed gas and processed material 6 are removed to the outside of the discharge gap.

The machining fluid is heated and its temperature rises due to the roles of (+) and (2) and losses from pumps, throttle valves, etc. When the temperature of the machining fluid rises above room temperature, the mechanical parts of the electrical discharge machine that come into contact with the machining fluid undergo local thermal expansion, causing hll I vg
Affects nails. Furthermore, the temperature of the machining fluid is related to the roughness of the finished surface and the clearance, and in order to obtain a stable machining process, it is necessary to maintain the temperature at an appropriate temperature.

For this reason, methods are generally used in which the machining fluid is cooled by a heat exchanger passing cold water or the like, or the machining fluid is passed through a radiator or the like to radiate heat into the air.

(Problems to be Solved by the Invention) As mentioned above, it is necessary to maintain the machining fluid in a wire electric discharge machine at an appropriate temperature. These devices have the problem that they occupy a relatively large space and are complicated.

This invention was devised by focusing on these problems, and provides a simple method for cooling machining fluid in a wire electrical discharge machine using compressed air that can be easily used in factories. The purpose is to provide A'.

[Structure of the Invention] (Means for Solving the Problems) In order to achieve the above-mentioned object, the processing fluid cooling method of the present invention includes a method for cooling a processing fluid at the bottom of a processing fluid storage tank for expansion of compressed air. Compressed air is supplied to the bubble generator equipped with a large number of pores, and countless bubbles are released into the storage tank to cool the processing liquid.

(Function) The bubbles generated in the processing fluid by this method have the following characteristics.

(1) Air used in factories and the like is usually cooled to around room temperature, and its temperature is at least lower than the temperature of the machining fluid in electrical discharge machines. That is, there is a temperature difference.

(2) The surface area of a bubble increases in inverse proportion to its diameter. This bubble generating product number generates relatively small bubbles, so the surface area that comes into contact with the 110 liquid is large relative to its volume. That is, the heat transfer area is large.

(3) When air bubbles come into contact with the processing fluid, a portion of the added water evaporates. This latent heat of vaporization cools the machining fluid itself by 1J.

(4) The agitation effect of the bubbles makes the liquid uniform.

Due to the above-mentioned characteristics, the processing liquid in the storage tank is effectively cooled by 11 degrees of air bubbles generated from the bubble generator.

(Example) Next, an example of the present invention will be described based on the drawings. FIG. 1 is a diagram showing the i@ring path of machining fluid in a wire electrical discharge machine that implements the method of the present invention. As shown, the contaminated and heated machining liquid from the machining tank 1 flows into the dirty liquid tank 3, where relatively large machining liquid is deposited. The supernatant liquid of sewage 1 and 3 is passed through a filter 7 by a pump 5, and fine particles are collected and sent to a clear liquid tank (storage tank) 9. The machining liquid in the fresh liquid tank 9 is cooled by countless bubbles 13 generated from a bubble generator 11 in the method of the present invention, which will be described later, and then passed through a throttle valve, a pressure gauge, etc. by a machining liquid supply pump 17, and then transferred to the machining tank 9. Upper and lower nozzles in 1.9.
2.1. The machining fluid is ejected here to cool the wire electrode and the machining H, remove machining waste, etc. This machining fluid is circulated and used again via the above-mentioned route.

The bubble generator 11 is made of a porous flat plate with an air passage inside, and compressed air is supplied from an air supply port 15 through a conduit. The compressed air turns into countless bubbles from the porous flat plate of the bubble generator, is released into the processing fluid, cools the processing fluid, reaches the product temperature, and escapes out of the tank.

The bubble generator of this embodiment turns compressed air itself into bubbles, but it uses the flow velocity of compressed air engraving to suck in outside air and release it into the tank as bubbles. It would be even more efficient if

[Effect of the invention] As understood from the above explanation, the present invention has the following advantages:
'F Since it has the configuration described in the scope of claims,
It is possible to provide a method for cooling the machining fluid of a wire electric discharge machine, which can cool the machining fluid using compressed air that is easily available in I, etc., and using a bubble generator with a simple structure.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram showing a fresh liquid tank (storage tank), a bubble generator, and a processing fluid circulation path E9 in which the present invention is implemented. Explanation of the symbols representing the main parts of the drawing 1...Processing tank 3...Dirty liquid tank 9...Clean liquid tank 11...Bubble generator 13...Bubble
15...Air supply port 17...Processing liquid supply pump 19...Upper nozzle 21...Lower nozzle ゛Agent: Yasuo Miyoshi, patent attorney

Claims (1)

[Claims] A bubble generator with a large number of pores is installed at the bottom of the processing fluid storage tank, and a wire is used to supply compressed air to this bubble generator and release countless bubbles into the storage tank to cool the processing fluid. Method for cooling machining fluid in electrical discharge machines.