JPH038893B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] This invention generates electrical discharge between a continuously supplied wire electrode and a workpiece, and processes the workpiece using the discharge energy. This invention relates to a wire cut electric discharge machine.

[Prior Art] Conventionally, wire cut electrical discharge machining has been performed using an immersion type method in which a workpiece is placed in a machining tank filled with machining fluid, and the wire electrode and the machining tank are moved relative to each other to perform machining. In this type of device, an arm having an electrode guide for guiding a wire electrode is inserted through an opening formed in the processing tank toward the workpiece. When the processing tank and the wire electrode are moved relative to each other during processing of the workpiece, the arm is moved in the longitudinal direction so that the processing liquid in the processing tank does not leak to the outside through the opening. There is a method in which a seal plate larger than the opening is provided, which is slidably inserted through the processing tank and is disposed so as to be movable relative to the processing tank, and the opening is sealed with the seal plate.

[Problems to be Solved by the Invention] As described above, in a device that seals an opening with a seal plate larger than the opening, it is difficult to maintain a complete seal even when the arm is relatively moved to one end of the opening. In order to hold it, it is necessary to prepare a plate that is quite large in relation to the opening, and the processing tank in which the plate is placed needs to be very large, which not only increases the size of the equipment but also increases the cost. The dot was hot.

[Object of the invention] The present invention solves the above problems,
It is an object of the present invention to provide a wire cut electrical discharge machine that can reliably prevent machining fluid in a machining tank from leaking without increasing the size of the device.

[Means for Solving the Problems] The wire-cut electrical discharge machine of the present invention generates electrical discharge between the wire electrode 7 and the workpiece W that are continuously supplied, and uses the discharge energy to cut the workpiece. In a wire cut electrical discharge machine for processing a workpiece W, a processing tank 2 that supports the workpiece W;
It extends toward the workpiece W through a long hole 21 formed in the side wall of the processing tank 2 in a substantially horizontal direction, and is arranged so as to be movable horizontally relative to the processing tank 2. An arm 5 has an electrode guide 6 for guiding the wire electrode 7, and both ends thereof are wound and supported by a take-up reel 29, and the intermediate portions of both ends are connected to the upper and lower side walls of the long hole 21 of the processing tank 2. a flexible strip-shaped shield 32 that is slidably supported by the arm 5 and provided with a fitting hole 37 approximately in the center for slidably fitting the arm 5;
and a storage section 22 that stores the winding portions at both ends of the shield 32, and the shield 32 provides space between the opening periphery of the long hole 21 of the processing tank 2 and the arm 5.
It is characterized by being configured to seal.

[Function] According to the present invention, with the above-described configuration, when the arm is moved horizontally relative to the processing tank, the shield is also moved in the same direction, and the shield is removed from the winding part in one storage section. is pulled out, and at the winding section in the other storage section, it is wound onto a take-up reel by the elastic force of the shield itself and is easily stored in the storage section. Furthermore, since the intermediate portions of both winding portions are slidably supported on the upper and lower side walls of the long hole of the machining tank, leakage of the machining fluid in the machining tank is reliably prevented.

[Example] Hereinafter, an example of the present invention will be described in detail with reference to the drawings.

Now, in the wire-cut electrical discharge machine of this embodiment, as shown in FIG. The workpiece W can be supported in a state where L is filled. An upper arm 3 is provided on the frame 1 above the processing tank 2, and an upper electrode guide 4 made of a conductive roller is supported at the lower part of the upper arm 3 so as to be movable and adjustable in the vertical direction. A lower arm 5 made of a conductive cylindrical body is insulated from the frame 1 on the side of the frame 1 so as to penetrate the side wall of the processing tank 2 and extend horizontally to a position below the workpiece W. A lower electrode guide 6 made of a conductive roller is supported at the tip of the lower electrode guide 6 while being insulated from the lower arm 5 .

A feeding device 8 for feeding a wire electrode 7 made of a metal wire is provided at the top of the frame 1, and a winding device 9 for winding up the wire electrode 7 is provided at the bottom of the frame 1. . Then, the wire electrode 7 fed out from the supply device 8 is guided to the winding device 9 through the guide roller 10, the upper electrode guide 4, the lower electrode guide 6, and the guide roller 11, and is wrapped between the electrode guides 4 and 6. It is adapted to be continuously supplied onto the workpiece W.

A power supply circuit is connected between the wire electrode 7 and the workpiece W, and a pulse discharge is repeatedly generated in the machining gap between the wire electrode 7 and the workpiece W, and the workpiece W is machined by the discharge energy. It's summery. That is, in the power supply circuit, the DC power supply 1
A source terminal of a field effect transistor 13 is connected to one terminal of the transistor 2, and a switching control circuit 14 for controlling the switching operation of the transistor 13 is connected to its gate terminal.
A diode 15 and a resistor 16 are connected between the drain terminal of the transistor 13 and the other terminal of the power supply 12 to eliminate reactance caused by the switching operation of the transistor 13. The workpiece W is connected to the ground side terminal of the power supply circuit via the conductive lower arm 5, and the wire electrode 7 is connected to the other terminal of the power supply circuit via the lower electrode guide 6.

A pump 17 is connected to the lower arm 5, and the operation of the pump 17 fills the machining fluid L from the machining fluid tank through the inside of the lower arm 5 into the machining tank 2 at the start of work, and fills the machining fluid L into the machining tank 2 during machining work. The machining liquid L can be supplied to the machining gap between the wire electrode 7 and the workpiece W.

Next, the seal structure of the lower arm penetrating portion of the processing tank 2 and the internal structure of the lower arm 5, which are the main parts of the present invention, will be explained in detail based on FIGS. 2 to 6.

In this embodiment, a long hole 21 for inserting the lower arm 5 is formed near the lower end of the side wall of the processing tank 2 so as to extend substantially horizontally. Accommodating recesses 22 are formed on the outer surface of the side wall of the processing tank 2 on both sides. A groove 23 for catching leakage water from the processing tank 2 is formed on the top surface of the bottom wall of the processing tank 2 so as to extend outside the long hole 21 and along the long hole 21. A drain port 24 is formed in the side wall of the processing tank 2 so as to communicate with the processing tank 2 .

A guide plate 25 is attached to the outer surface of the side wall of the machining tank 2 in correspondence with the long hole 21, and an opening 26 is formed approximately in the center of the guide plate 25 in correspondence with the long hole 21. As shown in FIGS. 2, 3, and 5, this guide plate 25 allows long holes 2 to be formed on the outer surface of the side wall of the processing tank 2.
A pair of guide grooves 27 are formed extending horizontally along the top and bottom of 1.

A pair of upper and lower support plates 28 are attached to the inner surfaces of the left and right sides of the guide plate 25, respectively, and are arranged to protrude into the accommodation recess 22 of the processing tank 2. A take-up reel 29 is rotatably supported between a pair of upper and lower support plates 28 in both accommodation recesses 22 . In this embodiment, each take-up reel 29 includes a pair of upper and lower discs 30 and both discs 30.
The rotating shaft 31 is fitted and fixed to the rotating shaft 31.

A flexible strip-shaped shield 32 is wound and supported on both the winding reels 29 at winding portions at both left and right ends, and the intermediate portion between the winding portions is connected to the long hole 21 of the processing tank 2. The guide plate 25 is slidably inserted and supported in the guide groove 27 between the guide plate 25 and the opening 26 of the guide plate 25 . A through hole 33 formed approximately in the center of the shield 32
A sealing body 34 is fitted to the hole 33 , and a fixing plate 35 is fitted to the inner end of the sealing body 34 with the shielding body 32 sandwiched therebetween, and a plurality of screws 36 are screwed into the fixing plate 35 . is fixed around the periphery of the The lower arm 5 is located at the center of the seal body 34.
A fitting hole 37 is formed into which the lower arm 5 is slidably fitted, and a packing 38 is provided on the inner periphery of the fitting hole 37 to fit tightly onto the outer circumferential surface of the lower arm 5.

In this embodiment, the shielding body 3
As shown in FIG. 5, the shield 32 has the property of curving outward at its center in the width direction, and based on this, both upper and lower edges of the shield 32 come to tightly engage with the guide groove 27. ing. Therefore, the gap between the opening periphery of the long hole 21 of the processing tank 2 and the lower arm 5 is always kept in a sealed state by the shield 32. In addition, the shielding body 32 has the property of being wound at each winding portion by its own elastic force, and when the shielding body 32 is moved relative to the processing tank 2, one winding portion is wound. While being unwound, the other winding portion is wound up by its own elastic force.

On the other hand, as shown in FIG. 6, an end plate 39 made of an insulating material is fitted and fixed to the outer end of the lower arm 5 made of a conductive cylindrical body with a plurality of screws 40 as described above. A plurality of support plates 41 made of an insulating material are arranged at predetermined intervals in the lower arm 5, and between the support plate 41 located on the innermost side (on the right side in FIG. 6) and the end plate 39. A plurality of holding rods 42 are installed. A wire guide pipe 43 is supported through the end plate 39 and the support plate 41 so as to extend in the longitudinal direction at the lower part of the lower arm 5, so that the wire electrode 7 can be inserted and guided therethrough. A power supply line 44 is supported through the end plate 39 and the support plate 41 so as to extend in the longitudinal direction near the center of the lower arm 5, and power is supplied to the wire electrode 7 via this power supply line 44. ing.

In addition, a water supply pipe 45 is supported through the end plate 39 and the support plate 41 so as to extend in the longitudinal direction near the other side of the center of the lower arm 5, and is connected to the wire electrode 7 through this water supply pipe 45 during processing operations. A machining liquid L is supplied to a machining gap between the workpiece W and the workpiece W. A supply pipe 46 is supported through the end plate 39 at the upper part of the outer end of the lower arm 5. At the start of work, etc., the machining liquid L is supplied into the lower arm 5 through the supply pipe 46, and is applied to the inner wall of the lower arm 5. The machining liquid L is filled into the machining tank 2 through a guide passage formed by the process.

Further, as shown in FIG. 5, a conductive bracket 48 is attached to the inner end of the lower arm 5 via an insulating plate 47, and the lower electrode guide 6 is rotatably supported at the tip of this bracket 48. It is designed to guide the wire electrode 7 around. A pair of cylindrical bodies 49 and 50 for passing the wire electrode 7 therethrough is mounted on the bracket 48, and a guide body 51 for guiding the wire electrode 7 is disposed inside the cylindrical body 49,50. A fitting hole 52 is formed in a part of the bracket 4 , and the inner end of a power supply line 44 is fitted into this fitting hole 52 , and the power supply line 44 is connected through the bracket 48 and the lower electrode guide 6 . Electricity is supplied to the wire electrode 7. Further, a connection port 53 is formed on the bracket 48 , and the inner end of the water supply pipe 45 is connected to this connection port 53 via a coupling ring 54 .
The machining liquid L is supplied to the machining gap through the continuous passages 55, 56 of 8 and the cylindrical body 49 which acts as a nozzle.

Therefore, during machining with this wire cut electric discharge machine, when the lower arm 5 is relatively moved in the X direction in FIG. 3 as the machining tank 2 moves in the horizontal direction,
The shielding body 32 is also moved in the same direction and wound up or unwound by the winding portions at both ends, and when the lower arm 5 moves in the Y direction, the lower arm 5 is moved to the sealing body 34 on the shielding body 32. is slid along the fitting hole 37 of. For this purpose, the gap between the opening periphery of the long hole 21 provided in the side wall of the processing tank 2 and the lower arm 5 is always kept in a sealed state by the shield 32, and the machining liquid in the processing tank 2 is leaked from the gap. It is possible to reliably prevent L from leaking.

Further, in this embodiment, the lower arm 5 is formed of a conductive cylindrical body and is connected to the ground side terminal of the power supply circuit, and a wire electrode 7 is inserted and guided inside the lower arm 5. Since a power supply line 44 for connecting the other terminal of the power supply circuit is inserted through the wire electrode 7, noise is absorbed by the lower arm 5 and the noise is prevented from leaking to the outside. be able to.

It should be noted that the present invention is not limited to the configuration of the above-mentioned embodiments, and the configuration of each part can be arbitrarily changed and embodied without departing from the spirit of the invention.

[Effects of the Invention] As detailed above, in the present invention, both ends of the flexible shield are wound and supported on the take-up reel, so that the shield does not move relative to the processing tank. When the shield is removed, it is pulled out from one storage part, and in the other storage part, it is wound up on a take-up reel by the elastic force of the shield itself, so that the shield can be easily stored in the storage space. Moreover, since the shield is wound at both ends, the storage space becomes very compact, which can greatly contribute to the miniaturization of the entire device. Furthermore, since the intermediate portions of both winding portions are slidably supported on the upper and lower side walls of the long hole of the machining tank, leakage of the machining liquid in the machining tank is reliably prevented.

[Brief explanation of the drawing]

FIG. 1 is a partial cross-sectional view showing an outline of a wire-cut electric discharge machine embodying the present invention, FIG. 2 is a partially cut-away rear view showing an enlarged view of the machining tank, and FIG. 4 is a partially enlarged sectional view taken along the line B-B in FIG. 2, FIG. 5 is a partially enlarged sectional view taken along the line C-C in FIG. 2, and FIG. 6 shows the lower arm. FIG. 2 is a partially enlarged cross-sectional view taken along the axis of the pipes and the like inside thereof. 2 is a processing tank, 5 is a processing arm, 6 is a processing electrode guide, 7 is a wire electrode, 21 is a long hole, 27 is a guide groove, 32 is a shielding body, 34 is a sealing body, 37 is a fitting hole, and W is a cover. It is a processed product.

Claims (1)

[Scope of Claims] 1. A wire-cut electrical discharge machine that generates an electrical discharge between a continuously supplied wire electrode 7 and a workpiece W, and processes the workpiece W using the discharge energy, comprising: A processing tank 2 that supports the workpiece W, and a long hole 21 formed in the side wall of the processing tank 2 in a substantially horizontal direction, extending toward the workpiece W, and horizontally with respect to the processing tank 2. an arm 5 which is arranged so as to be relatively movable and has an electrode guide 6 for guiding the wire electrode 7; A fitting hole 3 is slidably supported on the upper and lower side walls of the elongated hole 21 of the tank 2, and approximately in the center thereof is a fitting hole 3 for slidably fitting the arm 5.
A flexible strip-shaped shield 3 provided with a
2, and a storage part 22 for storing the winding portions at both ends of the shield 32, and the shield 32 seals the space between the opening periphery of the long hole 21 of the processing tank 2 and the arm 5. A wire cut electrical discharge machine characterized by being configured as follows.