JPS61260934A - Device for filtering machining liquid for electric discharge machining - Google Patents

Abstract

PURPOSE:To increase the life of a filter while obtain a stable electric discharge machining operation by dividing the filtering of said machining liquid into one for rough machining operation and one for finishing operation and using a filter suited for each operation. CONSTITUTION:When a rough machining is carried out, a dirty liquid discharging solenoid valve 38 and a clean liquid feeding solenoid solenoid valve 42 are opened while operating a clean liquid feed pump 41 and a filter pump 45. A paper filter with an open mesh of 10-20 micron is used for a filter 46, to carry out a favorable operation, while also increase the life of the filter. When a finishing is carried out, a dirty liquid discharging solenoid valve 48 and a clean liquid feeding solenoid valve 52 are opened while operating a clean liquid feed pump 51 and a filter pump 55. A paper filter with a highly fine mesh of 3-5 micron is used for a filter 56, obtaining a stable finishing operation. Thus, by using separate filters each suited for rough machining and finishing, a stable operation can be obtained.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a machining fluid filtration device for an electric discharge machine.

[Conventional technology]

The configuration of an electric discharge machine 21 equipped with a conventional machining fluid filtration device 20 illustrated in FIG. The processing machine has an electrode 2 that is servo-fed by a servo head 5 above the processing machine, and a processing liquid tantalum that is a partition between the inside of the processing tank and the clean gWi 22 and dirty liquid tank 26 of the processing liquid filtration device. The sewage tank is communicated with the sewage tank through a sewage extraction pipe 24 to drain the sewage g.
25, the filtered clean liquid 26 is supplied from the clean liquid tank via the processing liquid supply pump 9 to the processing tank through the clean liquid supply pipe 27, and the waste liquid in the dirty liquid tank is further transferred to the filter pump 8. There is also a conventional filtration device 20 which filters the machining fluid through a machining fluid filtration pipe 28 with a machining fluid filter 7 interposed therein and supplies the fluid as fresh liquid 26 to the fresh fluid tank.

During the electrical discharge machining operation, carbon particles, microparticles from the workpiece 1 and microparticles from the electrode 2 are generated in the machining process WI4 and contaminate the machining fluid 3.
The heavy particles settle to the bottom of the tank, and the floating light particles are fed under pressure to the processing fluid filter 25 along with the liquid by the filter pump 8 and filtered. The liquid 26 is supplied to the clean liquid tank 22, and then supplied to the machining machine by the machining liquid supply pump 9 and used for circulation in the electric discharge machining operation. Note that a paper filter with a filtration accuracy of 6 to 5 microns is usually used as the processing liquid filter.

[Problem that the invention seeks to solve]

However, recently, in order to increase the machining speed, the machining power supply capacity has been increased to increase the machining current, especially in forging die machining, but in this case, the amount of scratches generated has increased significantly, and compared to the conventional method described above. Processing fluid filtration devices have problems such as a shortened filter life and an inability to perform a sufficient filtration function. As a result, maintenance work is time-consuming, ordinary costs increase, and filtration is not performed sufficiently, resulting in instability between the electrodes during finishing machining, which causes problems such as the machining process being delayed. I'm inviting you.

The purpose of this invention is to prevent the filter life from being shortened even when the occurrence of slatch increases significantly during electric discharge machining using a large machining current, and to enable stable machining even during finishing machining.

[A precautionary measure to resolve the problem]

In this invention, the machining liquid tank is divided into a clean liquid tank and a dirty liquid tank.
The processing tank is divided into two processing tanks: a finishing processing tank and a rough processing tank, and the former finishing processing tank has a filter with high filtration accuracy, and the latter rough processing tank has a filter with low filtration accuracy. During rough machining, the filtered machining liquid from the rough machining tank is used, and during finishing machining, the filtered machining fluid from the finishing machining tank is circulated.

[Effect]

Therefore, according to the configuration of the present invention, even if the machining fluid filtered by the filter with low filtration accuracy that is used for circulation during rough machining contains some slatch, it will not affect the machining itself, and will not affect the machining itself. On the other hand, the amount of dirt that has been filtered by the high-precision filtration filter that is circulated during finishing machining has a positive effect on increasing the rough machining speed.
Since the working fluid contains almost no slatch, stable finishing can always be carried out.

〔Example〕

Next, an embodiment of the present invention will be described with reference to the drawings.
In FIG. 1, an electric discharge machine 21 has a workpiece 1 placed on the inner bottom of a machining tank 4 in which a machining fluid 3 is stored, and an electrode 2 servo-fed by a servo head 5 arranged above the workpiece 1. The processing liquid filtration device 301 according to the present invention is attached to the processing liquid filtration device 301, and the processing liquid tank 31 of the filtration device includes a finishing tank 34 consisting of a finishing clear liquid tank 32 and a finishing dirty liquid tank 33, and a rough processing clearing tank 34. Liquid tank 35 and rough processing sewage tank 36
The rough machining tank 37 is divided into two machining tanks, and a rough machining sewage discharge solenoid valve 38 is interposed between the rough machining sewage tank 36 of the rough machining tank and the machining tank 4 of the electric discharge machine. The rough machining fluid tank 65 and the processing tank are connected by a rough machining fluid drain pipe 39 connected to the rough machining fluid drain pipe 39, and the rough machining fluid tank 65 is connected to the rough machining fluid drain pipe 39 and the rough machining fluid supply pump 41 and the rough machining fluid supply electromagnetic fluid. valve 42
The rough machining clean liquid supply pipe 46 is provided to connect the rough machining clean liquid supply pipe 46, so that the rough machining clean liquid 44 can be freely supplied. A low coarse rough machining filter 46 is interposed and connected by a rough machining liquid filtration pipe 47, and the rough machining waste liquid is filtered into a rough machining clear liquid 44 and stored. Further, the finishing sewage tank 66 of the finishing tank and the machining tank 4 of the electrical discharge machine are connected to a sewage extraction pipe 4 which is equipped with a finishing sewage discharge solenoid valve 48.
9 so that the finishing waste liquid 50 can be freely extracted, and the finishing liquid tank 32 and the processing tank are connected to the finishing liquid supply pump 51.
The finishing liquid supply electromagnetic valves 52 are connected to each other by interposed finishing liquid supply pipes 53, so that the finishing liquid 54 can be freely supplied. Further, the finishing sewage tank and the clear liquid tank are connected by a finishing processing liquid filtration pipe 57 which has a finishing processing filter pump 55 and a fine finishing processing filtration filter 56 with high filtration accuracy interposed therein. The finishing liquid 54 is filtered and stored, and the rough processing waste liquid removal pipe 39 and the finishing waste liquid removal pipe 49 may be separately connected to the processing tank 4. , may be connected after being combined in front of the processing tank (as shown in FIG. 1), and the clear liquid supply pipe 46 for the rough processing liquid and the clear liquid supply pipe 53 for the finishing clear liquid may be connected together. They may be connected to the processing tank separately, or they may be connected after being connected in front of the processing tank (as shown in FIG. 1).

Therefore, in this embodiment described above, when performing very rough machining where the average machining current is 120 to 500 A, the machining fluid in the rough machining tank 67 should be used to prevent a large amount of slap from occurring. In this case, the rough machining liquid discharge solenoid valve 68 and the fresh liquid supply solenoid valve 42 are respectively opened, and the rough machining fresh liquid supply pump 41 and filter pump 451 are respectively activated to perform filtration. If a coarse paper filter of about 10 to 20 microns, which has low filtration accuracy, is used for the filter 46, good rough machining work can be performed and the life of the filter can be greatly extended. It goes without saying that at this time, the finishing tank 34 is not used. Furthermore, a centrifugal separator or the like can be used in place of the rough processing filter. Next, when performing finishing machining with a relatively low machining current, the rough machining tank 67 is not used and the machining fluid in the finishing machining tank 64 is circulated. Discharge solenoid valve 48. The finishing fluid supply solenoid valve 52, the supply pump 51, and the filter pump 55 are respectively opened and activated, and the filtration filter 5
By using a 6 to 5 micron paper filter with high 6KVi filtration accuracy, a stable and fine finishing process can be achieved.

Next, another embodiment of Jin's invention will be described with reference to FIG. In place of the processing liquid filtration device 130 of the above-mentioned embodiment t,
A machining fluid filtration device 60 is attached to an electrical discharge machine 21, and a machining fluid tank 61 of the filtration device is connected to a finishing machining tank 62.
Just divide it into two processing tanks: 4W66 for rough processing and 4W66 for rough processing.
Each of the processing tanks and the processing tank 4 of the processing device are connected by a sewage extraction pipe 49 and a sewage extraction pipe 69 in which a finishing sewage discharge solenoid valve 48 and a rough processing sewage discharge solenoid valve 68 are interposed, respectively. The finished dirt N50 and the rough processing waste liquid 40 are drawn out, and each finishing filter pump 55, a plurality of finishing filter filters 56, and a finishing liquid supply solenoid valve 52 are installed. A finishing liquid supply pipe 56 is inserted. The finishing liquid 54 and the roughing liquid filtered in the respective roughing liquid supply pipes 43 are provided with a roughing filter pump 45, a plurality of roughing filters 46, and a roughing liquid supply solenoid valve 42. Processing liquid 44 can be freely supplied into the processing tank. Circulating the machining fluid in the machining system during each of the aforementioned machining operations is exactly the same as in the previous embodiment, and the effect remains unchanged. Since a sufficient filtration area is provided, the filter will not become clogged even during long-term machining, resulting in fluctuations in the flow rate and pressure between the poles and destabilizing the machining operation.

〔Effect of the invention〕

As described above, the present invention separates the filtration of machining fluid into rough machining and finishing machining operations, and uses filtration filters suitable for each of the aforementioned operations, thereby extending the life of the filter, and This invention can be said to have many practical benefits, such as the ability to easily achieve stable electrical discharge machining operations.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram of a circuit system showing an embodiment of the present invention;
FIG. 2 is an explanatory diagram of the circuit system of another embodiment, and FIG.
The figure is an explanatory diagram of a circuit system of an example of a conventional machining fluid filtration device for an electric discharge machine. DESCRIPTION OF SYMBOLS 21... Electrical discharge machine, 30... Machining fluid filtration device of the embodiment of this invention, 31... Machining fluid tank, 32...
Finishing liquid tank, 33... Finishing sewage tank, 34... Finishing tank, 65... Rough processing clear liquid tank, 66... Rough processing sewage tank. 37... Rough processing tank, 46... Rough processing filter. 56...Finishing filtration filter, 6o...Machining liquid filtration device of another embodiment of the present invention, 61...Machining liquid tank, 62...Tank for finishing process, 66...For rough machining Tank. Note that the same reference numerals in each figure indicate the same or equivalent parts.

Claims (1)

[Claims] The processing liquid tank is divided into two processing tanks, a finishing processing tank and a rough processing tank, each consisting of a clear liquid tank and a dirty liquid tank, and a filter with high filtration accuracy is used for the former finishing processing tank, and a filter with high filtration accuracy is used for the latter. Filters with low filtration accuracy are used for the filtration filters in the rough machining tank, and the filtration liquid from the rough machining tank is used during rough machining, and the filtration liquid from the finishing tank is used for finishing. A machining fluid filtration device for an electrical discharge machine, characterized by: