CN114654033A - Electric spark cutting machining device and method for chain type sheet electrode - Google Patents

Abstract

The invention discloses an electric spark cutting processing device and method of a chain type sheet electrode, wherein the device comprises a chain type sheet electrode structure, a pulse power supply, a working solution spraying mechanism for spraying working solution and a driving mechanism for driving the chain type sheet electrode structure to do cyclic motion, wherein the chain type sheet electrode structure comprises a chain and a plurality of sheet electrodes arranged on the chain, and a gap is formed between every two adjacent sheet electrodes; the positive pole of the pulse power supply is connected with a workpiece to be processed through a lead, and the negative pole of the pulse power supply is connected with the sheet electrode through a lead. The electrode of the device not only has the advantages of large carrying current and difficult fracture, but also has the advantage of high-speed motion processing, thereby being beneficial to discharging the corrosion removal products in the processing area and ensuring the stability and the high efficiency of processing.

Description

Electric spark cutting machining device and method for chain type sheet electrode

Technical Field

The invention relates to the technical field of electric spark machining, in particular to an electric spark cutting machining device and method for a chain type sheet electrode.

Background

In the electric spark machining, a tool electrode and a workpiece are respectively connected with two poles of a pulse power supply and immersed in working liquid, or the working liquid is filled into a discharge gap. The feeding of the tool electrode to the workpiece is controlled by the automatic gap control system, and when the gap between the two electrodes reaches a certain distance, the pulse voltage applied to the two electrodes breaks down the working liquid to generate spark discharge. A large amount of heat energy is instantaneously concentrated in a discharge micro-channel, the temperature can reach more than ten thousand ℃, and the pressure is also changed rapidly, so that a small amount of metal materials on the working surface at the point are melted and vaporized immediately, and are splashed into the working liquid in an explosive manner, and are rapidly condensed to form solid metal particles which are taken away by the working liquid.

In some application occasions, a shallow narrow groove (such as a cracking groove of an automobile connecting rod) needs to be machined on the surface of a conductive material, and the electric spark discharge cutting technology is one of common technical means and mainly comprises an electric spark wire cutting technology and a slice electric spark cutting technology; the wire-cut electric discharge machining technology is characterized in that a moving electrode wire is used for conducting pulse type spark discharge on a workpiece, the workpiece is melted or vaporized due to local high temperature, the electrode wire brings working liquid into a machining area, and then takes away corrosion removal products, so that a good insulation environment is kept between electrodes, and short circuit is avoided. The thin slice electric spark cutting technology utilizes metal thin slices to replace electrode wires, such as copper slices, molybdenum slices and the like, and the material erosion mechanism is consistent with that of electric spark wire cutting and is discharge erosion. The metal thin plate is used as a tool electrode to perform interpolar pulse discharge machining on the workpiece, thereby forming a notch on the surface of the workpiece.

In the prior art, the electrode wire in the electrospark wire-electrode cutting technology adopts a slender metal wire, the material of the slender metal wire is molybdenum wire, tungsten wire, brass wire and the like, and the diameter of the slender metal wire is 0.1-0.2 mm. Because of the small diameter, the electrode wire bears less limiting current. The machining efficiency is in direct proportion to the machining current, and small machining current means low machining efficiency; in addition, the wire electrode is also lost in the discharging process, and when the wire electrode is lost to a certain degree, the machine tool is broken under the action of the tension force, so that the machining of the workpiece is influenced. In order to solve the above problems, the prior art adopts a thin-sheet electric spark cutting technology, which has the advantages of large carrying current, difficult fracture and the like, but during machining, a tool electrode is a single thin-metal electrode, and during machining, the thin-metal electrode is still or linearly moved in a reciprocating manner at a low speed (such as an electromagnetic type, a mechanical type, a motor-driven type and the like), so that corrosion products in a machining area are difficult to discharge, short circuit is easy to occur, and machining efficiency is low.

Disclosure of Invention

The invention aims to overcome the existing problems and provides the electric spark cutting machining device for the chain type sheet electrode, and the electrode of the device not only has the advantages of large carrying current and difficult fracture, but also has the advantage of high-speed motion machining, thereby being beneficial to discharging the corrosion removal products in a machining area and ensuring the stability and the high efficiency of machining.

Another object of the present invention is to provide a method of electric discharge machining of a chain type foil electrode.

The purpose of the invention is realized by the following technical scheme:

an electric spark cutting processing device of a chain type sheet electrode comprises a chain type sheet electrode structure, a pulse power supply, a working solution spraying mechanism for spraying working solution and a driving mechanism for driving the chain type sheet electrode structure to do circular motion,

the chain type flake electrode structure comprises a chain and a plurality of flake electrodes arranged on the chain, and a gap is formed between every two adjacent flake electrodes; the positive pole of the pulse power supply is connected with a workpiece to be processed through a lead, and the negative pole of the pulse power supply is connected with the sheet electrode through a lead.

The working principle of the electric spark cutting machining device is as follows:

when the device works, a workpiece is clamped through a clamp, working liquid is sprayed in a processing area by a working liquid spraying mechanism, then a driving mechanism drives a chain to perform high-speed circular motion and drives a plurality of sheet electrodes on the chain to perform high-speed circular motion, and the sheet electrodes moving at high speed can bring the working liquid into the processing area and flow at high speed; then the workpiece is gradually close to the end part of the sheet electrode, and the interpolar gap between the sheet electrode and the workpiece is continuously reduced; when the gap between electrodes reaches a proper range (generally 10-150 μm), pulse spark discharge is generated between the sheet electrode and the workpiece, and the workpiece material is melted at high temperature and even vaporized; discharging explosive force to throw molten metal droplets out of the processing area, and forming corrosion removal products by the small metal droplets cooled by the working liquid; the working solution flowing at high speed is used for flushing and taking away the corrosion products, so that short circuit caused by lapping of the corrosion products is avoided; and finally, continuously feeding the workpiece until the workpiece is machined, stopping discharging, resetting the clamp, taking down the workpiece, and preparing for machining the next workpiece.

In a preferred aspect of the present invention, the driving mechanism includes a power source, a driving sprocket, and a driven sprocket; wherein the power source is connected with the driving chain wheel; the chain is arranged between the driving chain wheel and the driven chain wheel, one end of the chain is connected with the driving chain wheel in a matched mode, and the other end of the chain is connected with the driven chain wheel in a matched mode. Through setting up above-mentioned structure, the power supply drives drive sprocket and rotates, under driven sprocket's cooperation for the chain takes place cyclic rotation motion, thereby drives a plurality of thin slice electrodes and carries out cyclic motion, thereby realizes the processing to the work piece.

Preferably, the chain is formed by sequentially connecting a plurality of linking units in series, the plurality of sheet electrodes are respectively arranged on each linking unit, and the plurality of linking units correspond to the plurality of sheet electrodes one to one. By adopting the structure, on one hand, the processing efficiency of the workpiece can be improved, on the other hand, the mutual independence between each thin sheet electrode can be ensured, the working liquid is conveniently brought into a processing area, and thus, the corrosion removal products in the processing area are discharged.

Preferably, the driving chain wheel and the driven chain wheel are vertically distributed, the working solution spraying mechanism sprays the working solution from the upper part of the processing area, and the moving direction of the thin sheet electrode close to one end of the workpiece is the same as the gravity direction. Its aim at, when the chain was at high-speed when moving, the working solution sprayed from the processing region top can be more fully bring the working solution into the processing region, because the direction that the thin slice electrode that is close to work piece one end moved is the same with the gravity direction, under the effect of self gravity, the working solution also can flow downwards fast, and the result of corroding also can drop downwards, under the drive of thin slice electrode, is favorable to corroding the discharge of result more.

Preferably, the link unit comprises an inner link and an outer link hinged on the inner link, the inner link comprises an inner chain plate, a pin shaft and a shaft sleeve, and the outer link comprises an outer chain plate; the thin-sheet electrode is fixed on the outer chain plate. By adopting the structure, the sheet electrode can be better fixed on the chain, so that the structure becomes more compact.

Preferably, one end of the lead on the positive pole of the pulse power supply is connected with the driving sprocket or the driven sprocket. The purpose is that the sheet electrode can be connected with the positive electrode of the pulse power supply through the conduction of the driving chain wheel or the driven chain wheel.

Preferably, the shape of the thin sheet electrode is any one of a rectangle, a T shape, an oblique T shape, a rounded T shape, a trapezoid and the like.

Preferably, the material of the sheet electrode is any one of a copper sheet, a molybdenum sheet, a tungsten sheet, a graphite sheet, a steel sheet, a nickel sheet and the like.

An electric spark cutting processing method of a chain type sheet electrode comprises the following steps:

(1) clamping a workpiece to be processed through a clamp, spraying working liquid on the top of a processing area from above by a working liquid spraying mechanism, and respectively connecting a pulse power supply to the workpiece and a sheet electrode;

(2) the driving mechanism drives the chain to do high-speed circulating motion from top to bottom and drives the plurality of thin sheet electrodes on the chain to do high-speed circulating motion, a gap is formed between every two adjacent thin sheet electrodes, and the thin sheet electrodes moving at high speed can carry working liquid to enter a processing area;

(3) the workpiece is continuously close to the end part of the sheet electrode, the interpolar gap between the sheet electrode and the workpiece is continuously reduced, and when the interpolar gap reaches the machining range, the sheet electrode carries out electric spark machining on the workpiece;

(4) and stopping discharging when the set machining depth is reached, resetting the clamp, taking down the machined workpiece, and preparing for machining the next workpiece.

Compared with the prior art, the invention has the following beneficial effects:

1. according to the electric spark cutting machining device for the chain type sheet electrode, the sheet electrode is used for machining a workpiece, the current which can be borne by the sheet electrode is increased, the sheet electrode is not easy to break in the discharging process, and higher and more stable machining efficiency can be realized.

2. According to the electric spark cutting device for the chain type sheet electrode, the chain type sheet electrode structure is arranged, the driving mechanism drives the chain to perform high-speed circulating motion and drives the plurality of sheet electrodes on the chain to perform high-speed circulating motion, so that working liquid can be carried into a machining area more favorably, the working liquid can be accelerated to flow in the machining area, corrosion products in the machining area can be taken away in time, and short circuit caused by lap joint of the corrosion products is avoided.

3. According to the electric spark cutting machining device for the chain type flake electrodes, the gap is formed between every two adjacent flake electrodes, and the gap is beneficial to carrying more sufficient working liquid into a machining area to flush the machining area, so that corrosion products in the machining area can be taken away in time, and the discharge of the corrosion products is more beneficial.

Drawings

Fig. 1 is a schematic configuration diagram of a first embodiment of an electric discharge machining apparatus for a chain type sheet electrode according to the present invention.

Fig. 2 is a schematic perspective view of the driving mechanism of the present invention.

Fig. 3 is a schematic perspective view of a link unit according to the present invention.

Fig. 4 is a schematic structural diagram of different shapes of the thin sheet electrode in the invention.

Fig. 5 is a schematic configuration diagram of a second embodiment of the electric discharge machining apparatus according to the present invention.

Fig. 6 is a schematic configuration diagram of a third embodiment of the electric discharge machining apparatus according to the present invention.

Detailed Description

In order to make those skilled in the art understand the technical solutions of the present invention well, the following description of the present invention is provided with reference to the embodiments and the accompanying drawings, but the embodiments of the present invention are not limited thereto.

Example 1

Referring to fig. 1, the present embodiment discloses an electric spark cutting device for a chain type sheet electrode, which includes a chain type sheet electrode structure, a pulse power source 2, a working fluid spraying mechanism 12 for spraying a working fluid, and a driving mechanism for driving the chain type sheet electrode structure to perform a cyclic motion, wherein the chain type sheet electrode structure includes a chain 6 and a plurality of sheet electrodes 1 arranged on the chain 6, and a gap is formed between two adjacent sheet electrodes 1; the positive pole of the pulse power supply 2 is connected with a workpiece 10 to be processed through a lead 3, and the negative pole is connected with the sheet electrode 1 through the lead 3.

Referring to fig. 1, in the electric spark cutting device for a chain type sheet electrode in the embodiment, a workpiece 10 is processed by the sheet electrode 1, so that the sheet electrode 1 can bear larger current, is not easy to break in a discharging process, and can realize higher and more stable processing efficiency; by arranging the plurality of sheet electrodes 1, the driving mechanism drives the chain 6 to perform high-speed circulating motion and drives the plurality of sheet electrodes 1 on the chain 6 to perform high-speed circulating motion, so that working fluid can be carried into a processing area more favorably, and the working fluid can be accelerated to flow in the processing area, thereby timely taking away corrosion products in the processing area and avoiding short circuit caused by lapping of the corrosion products; in addition, because a gap is formed between two adjacent sheet electrodes 1, the gap is beneficial to carrying more sufficient working liquid into a processing area to flush the processing area, so that corrosion products in the processing area can be taken away in time, and the discharge of the corrosion products is more beneficial.

Referring to fig. 1-2, the drive mechanism includes a power source, a drive sprocket 4, and a driven sprocket 5; wherein the power source is connected with the driving chain wheel 4; the chain 6 is arranged between the driving sprocket 4 and the driven sprocket 5, one end of the chain 6 is connected with the driving sprocket 4 in a matched manner, and the other end of the chain 6 is connected with the driven sprocket 5 in a matched manner; the plurality of sheet electrodes 1 are respectively disposed on the chain 6. Through setting up above-mentioned structure, the power supply drives drive sprocket 4 and rotates, under driven sprocket 5's cooperation for cyclic rotation motion takes place for chain 6, thereby drives a plurality of sheet electrodes 1 and carries out cyclic motion, thereby realizes the processing to work piece 10.

Referring to fig. 2 to 3, the chain 6 is formed by sequentially connecting a plurality of linking units 6-1 in series, a plurality of sheet electrodes 1 are respectively disposed on each linking unit 6-1, and the plurality of linking units 6-1 correspond to the plurality of sheet electrodes 1 one to one. By adopting the structure, on one hand, the processing efficiency of the workpiece 10 can be improved, on the other hand, the mutual independence between each sheet electrode 1 can be ensured, the working liquid is conveniently brought into the processing area, and thus, the corrosion removal products in the processing area are discharged.

Referring to fig. 1, the driving sprocket 4 and the driven sprocket 5 are distributed up and down, and the working fluid spraying mechanism 12 includes a nozzle disposed above the processing area, and the nozzle sprays the working fluid from above the processing area to below, and the moving direction of the thin-sheet electrode 1 near one end of the workpiece 10 is the same as the gravity direction. Its aim at, when chain 6 was at high-speed when moving, the working solution sprayed from the processing region top can be more fully brought the working solution into the processing region, because the direction that the sheet electrode 1 that is close to work piece 10 one end moved is the same with the gravity direction, under the effect of self gravity, the working solution also can flow downwards fast, and the result of corroding also can drop downwards, under the drive of sheet electrode 1, is favorable to corroding the discharge of result more.

Referring to fig. 1, the machining area is an area where the sheet electrode 1 and the workpiece 10 are discharged, that is, an area for cutting.

Referring to fig. 3, the link unit 6-1 comprises an inner chain link and an outer chain link hinged to the inner chain link, the inner chain link comprises two inner chain plates 6-11, two pin shafts 6-12 and two shaft sleeves 6-13, the two shaft sleeves 6-13 are arranged between the two inner chain plates 6-11, and the pin shafts 6-12 penetrate through the inner chain plates 6-11 and the shaft sleeves 6-13; the outer chain link comprises two outer chain plates 6-14, and the outer chain plates 6-14 are hinged on the inner chain plates 6-11 through pin shafts 6-12; the thin sheet electrodes 1 are fixed on the outer chain plates 6-14. With the above structure, the sheet electrode 1 can be fixed on the chain 6 better, so that the structure becomes more compact.

Referring to fig. 1, one end of a lead 3 on the positive electrode of the pulse power source 2 is connected to the driving sprocket 4 or the driven sprocket 5. The purpose is to connect the sheet electrode 1 to the positive electrode of the pulse power source 2 by conduction through the driving sprocket 4 or the driven sprocket 5.

Referring to fig. 4, the shape of the thin sheet electrode 1 is any one of a rectangle, a T shape, an oblique T shape, a trapezoid, a rounded T shape, and the like.

Referring to fig. 1, the sheet electrode 1 is made of a metal material or other conductive materials, such as any one of copper sheets, molybdenum sheets, tungsten sheets, graphite sheets, steel sheets, and nickel sheets.

Referring to fig. 1, the electric discharge machining apparatus described above operates on the following principle:

when the device works, firstly, a workpiece 10 is clamped through a clamp, working liquid is sprayed in a processing area by the working liquid spraying mechanism 12, then the driving mechanism drives the chain 6 to do high-speed circular motion from top to bottom, and drives the plurality of sheet electrodes 1 on the chain 6 to do high-speed circular motion, and the sheet electrodes 1 moving at high speed can bring the working liquid into the processing area and flow at high speed; then the workpiece 10 gradually approaches the end of the sheet electrode 1, and the interpolar gap between the sheet electrode 1 and the workpiece 10 is continuously reduced; when the interpolar gap reaches the machining range (generally 10-150 μm), pulse spark discharge is generated between the sheet electrode 1 and the workpiece 10, and the material of the workpiece 10 is melted at high temperature and even vaporized; discharging explosive force to throw molten metal droplets out of a processing area, and forming corrosion removal products by small metal droplets cooled by working fluid; the working solution flowing at high speed is used for flushing and taking away the corrosion products, so that short circuit caused by lapping of the corrosion products is avoided; and finally, continuously feeding the workpiece 10 until the workpiece 10 is machined, stopping discharging, resetting the clamp, taking down the workpiece 10, and preparing for machining the next workpiece 10.

Specifically, the power source may be a motor.

Referring to fig. 1, the embodiment further discloses an electric discharge cutting method for a chain type sheet electrode, which includes the following steps:

(1) clamping a workpiece 10 to be processed through a clamp, clamping the workpiece 10 on the right side of the sheet electrode 1, spraying working liquid on the top of a processing area by a working liquid spraying mechanism 12, respectively switching on a pulse power supply 2 for the workpiece 10 and the sheet electrode 1, and respectively connecting the positive electrode and the negative electrode of the pulse power supply 2 to the workpiece 10 and the sheet electrode through leads 3.

(2) The driving mechanism drives the chain 6 to do high-speed circular motion from top to bottom and drives the plurality of sheet electrodes 1 on the chain 6 to do high-speed circular motion, a gap is arranged between every two adjacent sheet electrodes 1, and the sheet electrodes 1 which do high-speed motion can carry working fluid to enter a processing area.

Specifically, the power source drives the driving sprocket 4 to rotate, and under the cooperation of the driven sprocket 5, the chain 6 generates circular rotation motion, so that the plurality of sheet electrodes 1 are driven to perform high-speed circular motion, and the sheet electrodes 1 which move at high speed can carry sufficient working solution to enter a processing area. The gaps between the foil electrodes 1 are favorable for carrying working fluid and flushing the processing area.

(3) Feeding the workpiece 10, and continuously approaching the end of the sheet electrode 1, wherein the interpolar gap between the sheet electrode 1 and the workpiece 10 is continuously reduced, when the interpolar gap reaches a proper processing range (generally 10-150 μm), pulse spark discharge is generated between the sheet electrode 1 and the workpiece 10, and the material of the workpiece 10 is melted at high temperature and even vaporized; the molten metal droplets are thrown out of the processing area or outside the processing area by the discharge explosive force, and the cooled small metal droplets form an etching product; the working solution flowing at high speed washes and takes away the corrosion products in time, thereby avoiding short circuit caused by lapping of the corrosion products. The high flow rate of the working solution is beneficial to interpolar deionization and prepares for next discharge.

(4) The continuous discharging processes a narrow groove on the surface of the workpiece 10, when the set processing depth is reached, the discharging is stopped, the clamp is reset, the processed workpiece 10 is taken down, and the next workpiece 10 is prepared for processing.

Example 2

Referring to fig. 5, the other structure in this embodiment is the same as embodiment 1 except that the driving mechanism is a belt-type driving mechanism including a driving source, a driving pulley 7, a driven pulley 8, and a belt 9 disposed between the driving pulley 7 and the driven pulley 8; wherein the drive source is connected with the driving pulley 7; one end of the belt 9 is connected with the driving belt wheel 7 in a matching way, and the other end of the belt is connected with the driven belt wheel 8 in a matching way; the plurality of sheet electrodes 1 are respectively arranged on the belt 9, and the driving source is a motor. Through setting up above-mentioned structure, the driving source drives driving pulley 7 and rotates for under driven pulley 8's cooperation, make belt 9 take place cyclic rotation motion, thereby drive a plurality of sheet electrodes 1 and carry out cyclic motion, thereby realize the processing to work piece 10.

The driving belt wheel 7, the driven belt wheel 8 and the belt 9 are all made of conductive materials.

Example 3

Referring to fig. 6, the other structure of the present embodiment is the same as that of embodiment 1, except that the driving sprocket 4 and the driven sprocket 5 are horizontally distributed, the workpiece 10 is directly immersed in the working fluid, the nozzle is disposed at the end of the processing area to accelerate the flow of the working fluid, the sheet electrode 1 is located above the workpiece 10, the moving direction of the sheet electrode 1 is a circular motion along the horizontal direction, and when the chain 6 moves at a high speed, the sheet electrode 1 also drives the working fluid to flow in the processing area, thereby discharging the corrosion products.

The present invention is not limited to the above embodiments, and any other changes, modifications, substitutions, combinations, and simplifications which do not depart from the spirit and principle of the present invention should be construed as equivalents and are included in the scope of the present invention.

Claims (9)

1. An electric spark cutting processing device of a chain type sheet electrode is characterized by comprising a chain type sheet electrode structure, a pulse power supply, a working solution spraying mechanism for spraying working solution and a driving mechanism for driving the chain type sheet electrode structure to do circulating motion,

the chain type flake electrode structure comprises a chain and a plurality of flake electrodes arranged on the chain, and a gap is formed between every two adjacent flake electrodes; the positive pole of the pulse power supply is connected with a workpiece to be processed through a lead, and the negative pole of the pulse power supply is connected with the sheet electrode through a lead.

2. The electric discharge machining apparatus for chain type sheet electrodes as claimed in claim 1, wherein the driving mechanism includes a power source, a driving sprocket and a driven sprocket; wherein the power source is connected with the driving chain wheel; the chain is arranged between the driving chain wheel and the driven chain wheel, one end of the chain is connected with the driving chain wheel in a matched mode, and the other end of the chain is connected with the driven chain wheel in a matched mode.

3. The electric discharge machining apparatus for chain-type sheet electrodes as claimed in claim 2, wherein the chain is formed by sequentially connecting a plurality of the link units in series, a plurality of the sheet electrodes are respectively provided on each of the link units, and the plurality of the link units correspond to the plurality of the sheet electrodes one to one.

4. The electric discharge machining apparatus for chain type sheet electrodes as claimed in claim 2, wherein the driving sprocket and the driven sprocket are vertically arranged, and the working fluid spraying means sprays the working fluid from above the machining area, and the direction in which the sheet electrode near one end of the workpiece moves is the same as the direction of gravity.

5. The electric discharge machining apparatus for chain type sheet electrodes as claimed in claim 3, wherein the link unit includes an inner link and an outer link hinged to the inner link, the inner link includes an inner link plate, a pin shaft and a bushing, and the outer link includes an outer link plate; the thin-sheet electrode is fixed on the outer chain plate.

6. The electric discharge machine for a chained foil electrode as set forth in claim 2, wherein one end of the wire on the positive electrode of the pulse power source is connected to the driving sprocket or the driven sprocket.

7. The electric discharge machining apparatus for chain type foil electrodes as claimed in claim 1, wherein the shape of the foil electrode is any one of a rectangle, a T-shape, a slant T-shape, a rounded T-shape, and a trapezoid.

8. The electric discharge machining apparatus for chain type foil electrodes as claimed in claim 1, wherein the foil electrode is made of any one of copper, molybdenum, tungsten, graphite, steel and nickel.

9. The electric spark cutting machining method of the chain type sheet electrode is characterized by comprising the following steps of:

(1) clamping a workpiece to be processed through a clamp, spraying working liquid on the top of a processing area from above by a working liquid spraying mechanism, and respectively connecting a pulse power supply to the workpiece and a sheet electrode;

(2) the driving mechanism drives the chain to do high-speed circular motion from top to bottom and drives the plurality of sheet electrodes on the chain to do high-speed circular motion, a gap is formed between every two adjacent sheet electrodes, and the sheet electrodes moving at high speed can carry working fluid to enter a processing area;

(3) the workpiece is continuously close to the end part of the sheet electrode, the interpolar gap between the sheet electrode and the workpiece is continuously reduced, and when the interpolar gap reaches the machining range, the sheet electrode carries out electric spark machining on the workpiece;

(4) and stopping discharging when the set machining depth is reached, resetting the clamp, taking down the machined workpiece, and preparing for machining the next workpiece.

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