JPH012819A - Processing tank of electrolytic processing equipment - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a machining tank of an electrolytic machining device, and in particular, it finishes the three-dimensionally shaped work surface of a workpiece in a short time and with high precision to achieve a mirror-like finish. The present invention relates to a machining tank of an electrolytic machining device that can obtain a glossy surface.

[Conventional technology] Conventional metal processing equipment fills the gap between the workpiece and the electrode with an electrolytic solution such as sodium nitrate or sodium chloride, flows this electrolytic solution at high speed, and inhibits stable electrolytic action. Electrolytic machining equipment (Japanese Patent Laid-Open No. 61-71921 and Japanese Patent Laid-Open No. 71921) that processes a workpiece by flowing a direct current to an electrode while removing electrolytic products, that is, eluted metal compounds, metal ions, hydrogen gas, etc. 60-44228
The workpiece and electrode are placed facing each other with a small gap in a kerosene-based machining fluid, etc., and connected to an appropriate power source to prevent instantaneous spark discharge or transient arc discharge from occurring in the gap. Electric discharge machining apparatuses (see Japanese Patent Publication No. 60-26646 and Japanese Patent Application Laid-Open No. 60-177819) are known that generate electric discharge energy and process a workpiece using the discharge energy.

[Problems to be Solved by the Invention] However, in the former electrolytic machining Ha, particularly in machining with a three-dimensional bottom (meaning machining of a three-dimensional structure formed in the shape of a concave hole), There are disadvantages in that it is difficult to precisely transfer the electrode to the workpiece and high precision surface quality cannot be obtained, and in the case of the latter electric discharge machining equipment, it is difficult to obtain good surface roughness. For example, manual surface polishing process is required for mirror finishing etc., which is disadvantageous in that surface finishing requires a lot of time and labor.

Therefore, the present applicant filed Japanese Patent Application No. 62-27616 for an electrolytic processing device that eliminates these disadvantages.
In this electrolytic processing equipment, when removing electrolytic products generated in the gap between the workpiece and the electrode housed in the processing tank, a pump is pumped from the clean tank of the electrolyte filtration device installed below the processing tank. The electrolytic solution was pumped up and removed by being ejected from an injection nozzle that was disposed toward the gap.

Therefore, the electrolytic solution spouted into the gap has been stored in the clean tank for a long time, and there are differences in conditions such as temperature from the electrolytic solution stored in the processing tank and used for processing. Conditions such as temperature unevenness occur in the electrolyte in the processing tank, and since the electrolyte is supplied by a pump and injection nozzle, precise control of the electrolyte supply is not possible, making the surface to be machined particularly complex. When finishing a workpiece with a large shape, there was an inconvenience that the surface quality of the workpiece surface was significantly impaired. In addition, there is a large head difference between the processing tank and the clean tank, which requires a large-capacity pump, which increases costs.

[Purpose of the Invention] Therefore, the present invention eliminates the above-mentioned disadvantages, and in particular, supplies the electrolytic solution between the workpiece and the electrode from an electrolytic solution storage tank provided in the processing tank, thereby improving the efficiency of the process in the processing tank. In addition to preventing uneven electrolyte conditions, it is possible to precisely control the supply of electrolyte, and to finish the three-dimensionally shaped work surface of a workpiece in a short time and with high precision to obtain a mirror-like glossy surface. The aim is to realize a machining tank for electrolytic processing equipment that can perform

[Means for Solving the Problems] In order to achieve this object, the present invention accommodates an electrolytic solution inside, and sets a workpiece and an electrode facing each other with a predetermined gap in the electrolytic solution, so that both In a machining tank of an electrolytic processing apparatus that performs finishing processing while supplying pulses between the gaps and removing electrolytic products generated in the gaps, the electrolytic products are intermittently supplied into the processing tank and into the gaps. The present invention is characterized in that an electrolyte storage tank is provided to temporarily store the electrolyte to be removed.

[Function] According to the configuration of the present invention, the electrolyte filtered by the electrolyte filtration device is temporarily stored in the electrolyte storage tank provided in the processing tank in which the workpiece and the electrode are accommodated, and the electrolyte solution is stored in the electrolyte storage tank. The temperature and other conditions of the electrolytic solution in the tank are made to be approximately the same as those already contained in the processing tank, and this electrolytic solution is transferred to the workpiece and the electrode using an electrolytic solution supply device that does not require a large-capacity pump or the like. The electrolytic products generated in the gap are removed. 1
' [Examples] Hereinafter, embodiments of the present invention will be described in detail and specifically with reference to the drawings. j 1st to 4th
The figure shows one embodiment of the invention. In FIGS. 1 to 3, 1 is an electrolytic processing apparatus having a processing tank according to the present invention,
This electrolytic processing apparatus 1 includes a workpiece fixing device 3 that fixes a workpiece 2, an electrode fixing device 5 that fixes an electrode 4, an electrode drive section 60, and a drive conversion section 7 that converts rotational motion into reciprocating motion.
A power supply device 8 that generates a pulse current, a motor drive control section 9
A control device 12 consisting of a processing condition control section IO and an electrolyte control section 11, a manual device 13 for inputting data etc. regarding the workpiece 2, an electrolyte filtration device 14, and an electrolyte supply device 15.
, the machining tank 16, the electrolyte storage tank 17 provided in the machining tank 16, etc.

The workpiece fixing device 3 is a tailor made of highly insulating granite or ceramics, and fixes the workpiece 2 machined, for example, by electrical discharge machining, with bolts 18 or the like. Further, the electrode fixing device 5 has an electrode 4 made of, for example, pure copper and used during the electric discharge machining, attached to the lower end of a rod 19 provided at the lower part thereof, so that the electrode surface 4a and the workpiece Ij2a of the workpiece 2 are connected to the lower end of the rod 19. −-like gap 2 in three-dimensional direction
Fix it to maintain o. and the electrode fixing device δ
is moved up and down by the electrode drive unit 6 and drive conversion unit 7 to set the gap 20 to a predetermined value. That is, the rotation of the motor 23 is controlled by control signals output from the motor drive control section 9 of the control device 12 based on signals from the rotary encoder 21 and the tacho generator 22 of the electrode drive section 6, and the rotational movement of the motor 23 is controlled. Drive converter 7
The electrode fixing device 5 is moved up and down by converting it into a reciprocating motion, and the electrode surface 4a and the surface to be processed 2a are separated by a predetermined gap 20.
Set to .

A power supply device 8 that supplies a pulse current with a current density (average current per unit area) of 70 A/am2 or less between the workpiece 2 and the electrode 4 operates to It generates a pulse current with a predetermined current density calculated according to the surface area of 2, and a DC power supply section 24 that obtains a DC voltage, and the DC voltage from the DC power supply section 24 is charged to a plurality of capacitors, and the capacitors are charged. The generated charge is transferred to the workpiece 2 and the electrode 4 by opening the discharge switch.
It has a charging/discharging section 25 that discharges the battery in between, and a charging/discharging control section 26 that controls the charging/discharging section 25.

The input device 13 inputs the material and surface area of the workpiece 2, the finishing margin and dimensional accuracy grade, the finished surface roughness, the initial electrode gap, etc., and sends these signals to the motor drive control section of the control device 12. 9 and the processing condition control unit IO.

The electrolytic solution filtration device 14 and the electrolytic solution supply device 15 filter an electrolytic solution containing electrolytic products generated during processing, and transfer the filtered electrolytic solution 30 to the electrolytic solution according to the control signal from the electrolytic solution controller 11. Electrode 4 and rod 19 from electrolyte storage tank 17
The liquid is ejected at a constant pressure into the gap 20 through a supply hole 27 provided in the gap 20 to remove electrolytic products generated between the workpiece surface 2a and the electrode surface 4a during machining. 4
It is configured as shown in the figure.

In FIG. 4, the machining fluid filtration device 14 filters an electrolyte 29 containing a large amount of electrolytic products out of the electrolyte 28 in the machining tank 16.
a dirty tank 32 that stores the water via a discharge pipe 31;
The electrolyte 29 in the dirty tank 32 is pumped into the electromagnetic pump 33.
A centrifugal separator 36 pumps up the electrolytic solution, passes it through a filter 34, and performs centrifugal pretreatment by rotation of a motor 35, and a clean tank 37 that stores the electrolytic solution 30 that does not contain electrolytic products separated by the centrifugal separator 36. , an electromagnetic pump 38 pumps up the electrolytic solution 30 of the clean tank 37 and supplies it to the electrolytic solution storage tank 17 formed by erecting a wall 17a on the bottom plate of the processing tank 16, and an electromagnetic pump 38 that pumps up the electrolytic solution 30 of the clean tank 37 and supplies the electrolytic solution 30 to the electrolytic solution storage tank 17, which is formed by erecting a wall 17a on the bottom plate of the processing tank 16, and a liquid level of the dirty tank 32. It has an upper limit float switch 39 and a lower limit float switch 40 for detection.

Further, the electrolyte supply tool @15 includes a check valve 41. ．． 42
through the electrolyte storage tank 17 and the rod 1, respectively.
A first cylinder 43 connected to the supply hole 27 of No. 9, and a second cylinder 4 connected in series to this first cylinder 43.
4, and a compressor 4G connected to this second cylinder 44 via a solenoid valve 45.

The electrolyte control unit 11 that controls the electrolyte filtration device 14 and the electrolyte supply device 15 operates the electromagnetic pumps 33 and 38 and the motor 35 based on the control signal from the processing condition control unit 10 to remove the electrolyte. 29 to electrolyte storage tank 1.
7, and the compressor 46
is actuated to operate the first and second cylinders 43 and 44, and the electrolyte 30 in the electrolyte storage tank 17 is transferred from the rod 19 and the supply hole 27 of the electrode 4 to the surface to be processed 2a and the electrode surface 4a. The liquid is controlled so as to be ejected into the gap 20.

Next, the operation of this electrolytic processing apparatus 1 will be explained based on the finishing method.

During finishing, the workpiece 2 machined into a desired shape by, for example, electrical discharge machining is fixed to the workpiece fixing device 3, and the electrode 4 used during the electrical discharge machining is fixed to the lower end of the rod 19 of the electrode fixing device 5. Then, the electrode 4 is lowered to bring its electrode surface 4a into opposing contact with the surface 2a to be processed of the workpiece 2, and the electrode 4 is placed together with the workpiece 2 in the processing tank 16.
immersed in the electrolyte 28 of Then, the electrode 4 is raised to a position that maintains the initial electrode gap, and when the electrolytic solution 28 fills between the surface to be processed 2a and the electrode surface 4a, finishing processing is started using that point as a processing origin.

In the first half of finishing, a pulse for improving surface roughness with a predetermined current density is supplied between the workpiece 2 and the electrode 4 from the power supply device 8 in response to a control signal from the processing condition control section 100. As a result, the material of the processed surface 2a is eluted. After supplying a predetermined pulse once or several times, the electrolytic solution 29 containing the electrolytic product in the gap 20 is transferred to the cylinder 43. of the electrolytic solution supply device 15.
44 or the like, the electrolytic solution 30 spouted from the supply hole 27 is removed.

After removing the electrolytic products, the electrode 4 is lowered and the electrode surface 4
a contacts the processed surface 2a. Thereby, the control device 12 compares the origin and the current position to measure the machining depth per machining (machining every 1 pulse or every few pulses).

After that, the processed surface 2a and the electrode surface 4a are separated by a predetermined gap 2.
The electrode 4 rises again so as to maintain the temperature at 0, and the electrolyte 28 (mixed with the ejected electrolyte 30) in the machining tank 16 is filled between the workpiece surface 2a and the electrode surface 4a, and the electrode 4 After reaching a predetermined position (a position where the electrode surface 4a maintains a predetermined gap 20 with the surface to be processed 2a), the electrolytic solution 28 becomes stationary (meaning a state in which the flow and movement of the electrolytic solution 28 almost stops)1.
After ~5 seconds, a pulse is supplied and the next processing is performed.

Here, the operations of the electrolytic solution filtering device 14 and the electrolytic solution supplying device 15 will be explained.

The electrolytic solution 29 containing electrolytic products discharged from the processing tank 16 via the discharge pipe 31 is stored in a dirty tank 32, and its liquid level is determined by the upper and lower float switches 39.
．． 40 and manually inputted to the electrolyte control section 11. The electrolyte control unit 11 outputs a drive signal to the electromagnetic pump 33 when the liquid level in the dirty tank 32 reaches a predetermined value, that is, when the liquid level is between the upper and lower float switches 39 and 40. , the electrolytic solution 29 in the dirty tank 32 is pumped up and sent through the filter 34 to a centrifugal separator 8136.

In the centrifugal separator 36, the tongue 35 rotates in response to a control signal from the electrolyte control unit 11, and the electrolyte 29 is separated.

Then, an electrolytic solution 3 that does not contain the separated electrolytic products
0 is stored in the clean tank 37 and the electrolyte control unit 1
The electromagnetic bong 138 is activated by the control signal from the electrolyte tank 13, and the electrolytic solution 30 is pumped up from the clean tank 37 and flows into the electrolytic solution storage tank 17.

The electrolytic solution 30 stored in this electrolytic solution storage tank 17
is placed under the same conditions as the electrolytic solution 28 housed in the processing tank 16 and becomes between the electrolytic solution 28 and the temperature and other conditions, and based on the control signal output from the processing condition control unit IO, It is ejected into the gap 20. That is, when a predetermined number of machining operations are completed, the electrolytic solution control section 11 outputs a signal to the compressor 46, supplies air to the cylinder 44, and moves the piston 44-a in the direction of {circle around (2)} in the figure. As a result, the piston 43-a of the cylinder 43 connected in series with the piston 44-a similarly moves in the {circle around (2)} direction, and as a result of this movement, the electrolyte 30 in the electrolyte storage tank 17 is pumped up, and the chamber A of the cylinder 43 is pumped up. A predetermined amount is stored inside. When a predetermined amount of the electrolyte 30 is stored in the chamber A, the electrolyte controller 11 outputs a signal to the compressor 46 to operate the solenoid valve 45 to discharge the air in the cylinder 44. As a result, the piston 44-a moves in the {circle around (2)} direction, and the piston 43-a of the cylinder 43 also moves in the {circle over (2)} direction, so that the electrolytic solution 30 in the chamber A is jetted out from the supply hole 27 into the gap 20. Note that the electrolytic solution 30 is prevented from flowing in directions other than a predetermined direction by check valves 41 and 42.

The finishing process as described above is repeated a predetermined number of times according to a command from the control device 12, and the cumulative value of the machining depth is determined by the input device 1.
Processing condition control unit l based on the input data input in step 3.
Compare with the machining depth setting value calculated in
When the current density becomes within 372, the control signal from the processing condition control unit 1O switches the pulses supplied from the power supply device 8 to pulses for forming a glossy surface whose current density exceeds 372, which is the current density in the first half of the finishing process. Then, using this pulse, machining is performed a predetermined number of times in the same manner as described above, and finishing machining is completed.

In the above embodiment, a pair of cylinders were provided as the electrolyte supply device, but the present invention is not limited to this in any way. For example, it may be configured by combining a small-capacity pump and an electromagnetic switch with a timer ready function. You may. Further, although the electrolytic solution storage tank is configured by having a wall erected on the bottom plate of the processing tank, for example, the electrolytic solution storage tank may be shaped like a container and housed in an appropriate position within the processing tank. Furthermore, it goes without saying that the present invention is not limited to the field of finishing of molds, and may be used, for example, in combination with an automatic conveyance device, for finishing of hypoid gears and the like after heat treatment.

[Effects of the Invention] As explained in detail above, according to the present invention, an electrolytic solution is contained inside, a workpiece and an electrode are disposed opposite to each other with a predetermined gap in the electrolytic solution, and a pulse is generated between the two. In addition to supplying
In a machining tank of an electrolytic machining device that performs finishing processing while removing electrolytic products generated in the gap, an electrolytic solution is once supplied into the machining tank to intermittently remove the electrolytic products by supplying it to the gap. Since the electrolytic solution storage tank is provided, the electrolytic solution that is ejected into the gap between the workpiece and the electrode and removes the electrolytic products generated in the gap and the electrolytic solution stored in the processing tank can be combined. The electrolyte supply device can be equipped with a pump, etc. with a corresponding capacity to pump up the electrolyte, since the electrolyte is supplied from an electrolyte storage tank placed at the same height. without needing,
In particular, it is possible to precisely control the electrolyte supply required when finishing a three-dimensionally shaped work surface, and it is possible to uniformize the processing conditions over the entire work surface, making it possible to achieve a mirror-like finish with high precision and minute surface roughness. A shiny three-dimensional metal surface can be obtained in a short time. Furthermore, since a large-capacity pump or the like is not required, costs can be reduced.

[Brief explanation of drawings]

FIG. 1 is a front view showing an electrolytic processing device according to the present invention, FIG. 2 is a side view of the device, and FIG. 3 is a schematic configuration diagram of the device.
FIG. 4 is a schematic configuration diagram showing an electrolyte supply device and an electrolyte supply device. '1... Electrolytic processing device, 2... Workpiece, 4...
electrode, 8... power supply device, 9... motor drive control section,
10... Processing condition control section, 11... Electrolyte control section,
12... Control device, 14... Electrolyte filtration device, 15
... Electrolyte supply device, 16... Processing tank, 17...
Electrolyte storage tank, 37...Clean tank. Patent applicant: Shigeo Suzuki, representative of Shizuoka Seiki Co., Ltd.

Claims (1)

[Claims] An electrolytic solution is contained inside, a workpiece and an electrode are placed opposite each other with a predetermined gap in the electrolytic solution, and a pulse is supplied between the two, and the electrolyte generated in the gap is In a machining tank of an electrolytic machining device that performs finishing processing while removing objects, an electrolytic solution storage tank is provided in the processing tank to temporarily store an electrolytic solution that is supplied to the gap to intermittently remove electrolytic products. A machining tank of an electrolytic machining device characterized by: