JP3623363B2 - Wire feeding device in wire electric discharge machine - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a wire feeding device in a wire electric discharge machine for machining a workpiece by generating an electric discharge phenomenon between a wire electrode and the workpiece.
[0002]
[Prior art]
A wire electric discharge machine is a machine tool that cuts out a workpiece such as cemented carbide or hardened steel by generating an electric discharge phenomenon between a wire electrode and the workpiece. When electric discharge machining is started, a wire electrode is inserted in advance into a start hole (machining start hole) drilled in the workpiece. When an interelectrode voltage is applied between the wire electrode that is continuously supplied and the workpiece, the workpiece W is discharged, and the workpiece W is subjected to electric discharge machining into a predetermined machining shape by the discharge energy. The machining of the workpiece is controlled by the NC device, and a continuous slit is formed in the workpiece according to the shape programmed in the NC device.
[0003]
When machining of a workpiece is completed and another workpiece is machined, or when the wire electrode is disconnected during electric discharge machining, the tip of the wire electrode is cut and removed, and the newly formed tip Is inserted into the machining slit including the start hole of the workpiece to set the wire electrode. As part of automating electrical discharge machining, wire electrode mounting work from wire electrode delivery to wire electrode cutting and re-insertion into the machining slit is automated.
[0004]
FIG. 5 is a view showing an automatic wire feeding apparatus of an annealing dry feeding system in which a wire electrode that has been annealed (annealed) and straightened is passed through a start hole without using a water flow. As shown in FIG. 5, the automatic wire feeding device supplies various direction changing rollers 61, tension rollers 62, brake rollers to feed the wire electrode 1 fed out from the source bobbin 60 to the machining slit (including the start hole) A. 63, a wire electrode supply system including a direction changing roller 64, a drawing roller 65, and the like. The drawn wire electrode 1 is taken up by a take-up reel or discharged to a used wire reservoir (for example, a waste wire hopper) attached to a processing tank (not shown). By guiding the wire electrode 1 with the upper wire head 66 and the lower wire head 67, the wire electrode 1 travels accurately with respect to the workpiece W while the lateral vibration is restricted between the two heads. The lower wire head 67 is supported at the tip of a lower arm attached to the head so as to hang down from above the processing tank, and includes a direction changing roller 64 inside. On the downstream side of the lower wire head 67, a drawing device such as a pair of drawing rollers 65 that draws the wire electrode 1 through the guide pipe and puts the wire electrode 1 in a tension state is attached to the outside of the processing tank. The wire electrode 1 that has been annealed and straightened is inserted into the start hole of the workpiece W from its tip. An example of this type of automatic wire feeder is described in Japanese Patent Laid-Open No. 2-145215.
[0005]
The workpiece W is fixed to the processing tank by appropriate clamping means or supporting means in a state where it is installed between the upper wire head 36 and the lower wire head 37 facing each other. The electric discharge machining for the workpiece W is performed in a state of being immersed in the machining liquid filled in the machining tank. The machining tank is driven in accordance with the machining shape of the workpiece W in a plane defined by the X-axis and the Y-axis, for example, by a cross slide composed of an X-axis table and a Y-axis table. The Y-axis table is driven in the Y-axis direction by the Y-axis servo motor on the bed base, and the X-axis table to which the processing tank is attached is driven in the X-axis direction by the X-axis servo motor on the Y-axis table.
[0006]
There are various wire diameters and materials of wire electrodes, but in general, a wire electric discharge machine uses a brass wire electrode with a wire diameter of φ0.2. The slit width is obtained by adding the discharge gap generated between the diameter of the used wire electrode and the workpiece W, and is, for example, about 0.25 to 0.3 mm. However, in a wire electric discharge machine, when a high machining accuracy such as about 0.1 mm is required as the slit width and the radius of the minimum corner, a thin wire electrode having a diameter smaller than that is used. . A thin wire electrode having a diameter of about φ0.1 or less is weaker than a wire electrode of a conventional size, and is easily bent or swayed. Therefore, a guide having a tapered surface is adopted so that a thin wire electrode is guided even if it is not straight.
[0007]
A die guide that is provided on the upper wire head and guides the wire electrode 1 to the start hole of the workpiece and a conventional wire guide used for the die guide have a structure as shown in FIGS. FIG. 6 is a longitudinal sectional view of a conventional die guide, FIG. 7 is an end view of the die guide shown in FIG. 6, and FIG. 8 is a sectional view of a wire guide disposed at the tip of the die guide shown in FIG. The die guide 80 includes a stainless steel guide holder main body 83 in which an internal thread 86 for connecting to another guide member is formed on the inner peripheral surface of the hollow hole 85. The hollow hole 85 forms a through hole of the die guide 80 communicating with the through hole of the upper wire head. A tapered guide portion 87 is formed inside the tapered portion 84 of the guide holder main body 83, and the hollow hole 85 is connected to the smallest through hole 88. A wire guide mounting hole 89 for mounting the wire guide 90 is formed at the distal end side of the through hole 88. The wire guide mounting hole 89 includes a small-diameter portion and a large-diameter portion that gradually increase in diameter from the diameter of the through-hole 88. Note that a tool engaging portion 84a is formed in the tapered portion 84 by cutting out a part of its outer surface.
[0008]
As shown in FIG. 8, the wire guide 90 includes a diamond wire guide member 93 made of diamond and a pair of tapered wires that sandwich the wire guide member 93 on both the upstream and downstream sides of the wire electrode 1 in the feeding direction. It comprises guide members 91 and 92. The tapered wire guide members 91 and 92 are made of an insulating material such as ruby, sapphire, or ceramics. The diamond wire guide member 93 is held by the holding member 97 so as not to be displaced in the radial direction in the wire guide mounting hole 89.
[0009]
The diamond wire guide member 93 and the holding member 97 of the wire guide 90 are mounted on the wire guide mounting portion 89 while being sandwiched between a pair of tapered wire guide members 91 and 92. That is, the upstream tapered wire guide member 91, the diamond wire guide member 93, and the holding member 97 are mounted on the small diameter portion on the back side of the wire guide mounting hole 89, and the tapered wire guide member 92 is mounted on the wire guide mounting hole 89. It is attached to the large-diameter portion on the outlet side. The taper-shaped wire guide member 91 has a taper-shaped guide hole 94 that is tapered toward the downstream side of the wire electrode 1 and has a central axis that coincides with the central axis of the through-hole 88. The tip of the wire electrode 1 guided through the hole 88 is guided to be guided to the guide hole 96 of the diamond wire guide member 93. On the other hand, the tapered wire guide member 92 provided on the downstream side of the wire electrode 1 also opens in a tapered manner toward the downstream side of the wire electrode 1 in order to process the workpiece W into a tapered surface. A tapered guide hole 95 having a central axis coinciding with the central axis of 88 is provided. That is, when machining the workpiece into a tapered surface, the wire electrode 1 is tapered so as not to interfere with the tapered wire guide member 92 until reaching the lower wire head 67 with the diamond wire guide member 93 as a fulcrum. The wire guide member 92 can extend at an arbitrary angle through a tapered guide hole 95 that is tapered toward the outlet side by about 90 °.
[0010]
[Problems to be solved by the invention]
By the way, in the wire electric discharge machine, when a wire electrode having a diameter smaller than φ0.2 that is usually used, for example, φ0.1 or less, is used, an annealing process is performed to straighten the wire electrode. Even in such a case, the wire electrode is easily bent, and in the wire electrode insertion process in which the wire electrode is inserted into the workpiece, the wire electrode is easily bent as the feeding amount becomes longer, and the operation rate of the wire electrode automatic supply device is lowered. In particular, a wire supply pipe that guides the wire electrode is disposed in the long supply path of the wire electrode from the wire feed roller to the upper wire head in order to prevent the wire electrode from bending. However, even if such a wire supply pipe is provided, if the position of the tip of the fine wire electrode becomes unstable and the tip of the wire electrode fluctuates in the supply pipe, the wire electrode at that position As a result, the wire electrode cannot be smoothly fed out in the supply pipe, and it is difficult to stably feed it out to the upper wire head.
[0011]
In the automatic wire feeder, the wire electrode is annealed so as to be straight. However, since the wire electrode is only guided by the upper guide of the upper wire head, the success rate when the wire electrode penetrates the start hole is low. In addition, since it is difficult to penetrate the wire electrode through the thin processing slit, after passing the wire electrode through the start hole having a large hole diameter, the wire electrode is advanced again along the already formed processing trajectory, and the wire The work of advancing the electrode to the processing start point was necessary. For this reason, wire electrode insertion work with a large time loss has been a cause of inefficiency in electric discharge machining work.
[0012]
Further, as shown in FIGS. 6 to 8, the conventional tapered wire guide members 91 and 92 have a tapered surface in which the tapered wire guide member 92 on the downstream side in the feeding direction of the wire electrode 1 is opened on the downstream side. For this reason, the ultrafine wire electrode 1 guided by the diamond wire guide member 93 may be swung back and forth and right and left because the position of the tip of the wire electrode 1 becomes unstable when the wire guide 90 is exited. is there. As a result, a phenomenon may occur in which the wire electrode 1 is not stably fed out to a predetermined machining slit formed in the workpiece W. If a plurality of machining slits are close to each other, there is a risk of entering an adjacent start hole or the like.
[0013]
Therefore, in the wire electric discharge machine as described above, even when the fine wire electrode is used for automatic supply, the wire electrode fed by the feed roller is supplied from the supply pipe to the upper wire head and from the wire guide to the workpiece. However, there is still a problem to be solved with respect to the accurate and smooth introduction to the machining slit.
[0014]
[Means for Solving the Problems]
An object of the present invention is to solve the above-mentioned problem, and even if a wire electrode having a smaller wire electrode size than a general size is used, the wire electrode is captured without disturbing the progress of the wire electrode. It is to provide a wire feeding device in a wire electric discharge machine capable of penetrating through a wire guide and a machining slit of a workpiece with a high success rate.
[0015]
The present invention includes a supply pipe held in a suspended state by a head, an upper wire head attached to the head at a position below the supply pipe so as to be movable up and down, and provided facing the upper wire head, and A lower wire head in which a workpiece is disposed between the upper wire head and a wire electrode fed from a wire electrode supply source, the supply pipe, the upper wire head, a hole formed in the workpiece, and the In the wire electric discharge machine, wherein a wire guide for sequentially passing through the lower wire head and guiding the wire electrode to the hole of the workpiece is provided on the exit side of the through hole of the upper wire head. The guide has a tapered shape provided on the upstream side in the feeding direction of the wire electrode and having a tapered tapered guide hole connected to the through hole. An ear guide member, a straight wire guide member provided on the downstream side in the feeding direction of the wire electrode and having a straight guide hole, and the taper shape sandwiched between the taper wire guide member and the straight wire guide member The present invention relates to a wire feeding device in a wire electric discharge machine characterized by comprising a wire guide member having a guide hole having a minimum diameter communicating with a guide hole and the straight guide hole.
[0016]
In the wire feeding device in the wire electric discharge machine, air is supplied to the supply pipe in the feeding direction of the wire electrode at least when the tip of the wire electrode is fed. The wire electrode is guided to the first die guide of the upper wire head by the guide action of the wire electrode by air.
[0017]
In addition, the supply pipe is held by the head via a supply pipe holder at the upper end of the supply pipe, and the supply pipe holder is connected to the supply pipe in a straight line and the holder through hole through which the wire electrode passes. And a fluid passage which is connected to the holder through-hole from the side and into which the air is fed.
[0018]
The tapered wire guide member and the straight wire guide member are formed of an insulator such as sapphire, ruby or ceramic.
[0019]
In the wire feeding device in this wire electric discharge machine, as described above, the wire guide disposed on the outlet side of the through hole of the upper wire head is provided on the upstream side in the feeding direction of the wire electrode and the upper wire head. A tapered wire guide member having a tapered tapered guide hole connected to the through hole, a straight wire guide member provided on the downstream side in the feed direction of the wire electrode and having a straight guide hole, and the tapered wire guide member and the straight Since the wire guide member has a guide hole with a minimum diameter that is sandwiched between the wire guide member and communicates with the tapered guide hole and the straight guide hole, the wire guide member is fed from the wire electrode supply source and supplied from the supply pipe. The tip of the wire electrode introduced into the through hole of the upper wire head is the taper of the wire guide. The taper guide hole of the wire guide member and the guide hole of the wire guide member having the guide hole of the smallest diameter are inserted while being guided in sequence, and further, the straight guide hole of the straight wire guide member does not swing sideways. , It is guided straight with respect to the hole formed in the workpiece placed between the upper wire head and the lower wire head, and the insertion into the hole formed in the workpiece succeeds with high probability. Also, even if the wire electrode is bent by guiding the tip of the wire electrode by flowing air through the supply pipe, the tip of the wire electrode is inserted into the hole formed in the workpiece. It is inserted more accurately.
[0020]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of a wire feeder in a wire electric discharge machine according to the present invention will be described below with reference to the drawings. FIG. 1 is a schematic explanatory view showing an example of a wire electric discharge machine to which the wire feeding device according to the present invention is applied, and FIG. 2 is a diagram of the wire electric discharge machine shown in FIG. Shows the die guide of the wire feeder Sectional view, FIG. 3 is shown in FIG. Dice guide Fig. 4 shows the end view of Fig. 2. Dice guide Shows the wire guide provided in Expansion It is sectional drawing. As the automatic wire feeder, the one having the structure shown in FIG. 5 can be adopted.
[0021]
In this wire electric discharge machine, for example, the head (see FIG. 5) constituting the main body of the machine is suspended in the upper wire head 2 for guiding the wire electrode 1 to the electric discharge machining portion of the workpiece W and into the machining tank 6. A lower wire head 3 disposed opposite to the upper wire head 2 is attached via a lower arm case, that is, a housing 13 provided at the tip of the lower arm (see FIG. 5). The lower wire head 3 receives the wire electrode 1 obtained by performing electric discharge machining on the workpiece W. Further, a pair of wire feed rollers 4 for feeding the wire electrode 1 with the wire electrode 1 sandwiched between them to feed the wire electrode 1 to the head, guide the feed pipe 5 through which the wire electrode 1 passes through the internal passage, and the wire electrode 1 Equipment such as a roller is provided.
[0022]
The upper wire head 2 incorporates a wire delivery port 7, a die guide 8, a jet nozzle 9, an electron feeder 10, and the like, as in the conventional wire head 2. The feed roller 14 rotatably supported by the housing 13 of the lower wire head 3 changes the direction of the wire electrode 1 and guides it. In the wake of the lower wire head 3, a drawing device such as a pair of drawing rollers (65, see FIG. 5) that pulls out the wire electrode 1 and puts the wire electrode 1 into tension is attached to a support member provided outside the processing tank 6. It is attached. Further, the lower wire head 3 is provided with a sensor (not shown) for detecting that the wire electrode 1 is inserted into the lower wire head 3, and the tip of the wire electrode 1 is a machining slit of the workpiece W. A, or when it is not inserted into the lower wire head 3, a supply failure detection signal is transmitted to the controller. The processing liquid is filtered and reused by a filtering device installed in the processing tank 6.
[0023]
The wire feed roller 4 also serves as an annealing roller and can move in the vertical direction with respect to the head. In addition, a pair of power supply rollers 17 are disposed corresponding to the lower portion of the supply pipe 5 so that a current for annealing treatment flows through the wire electrode 1 extending between the wire feed roller 4 and the wire feed roller 4. A cutter 16 for cutting the wire electrode 1 to form a new tip is disposed slightly upstream of the power supply roller 17. Further, a photoelectric sensor 18 for detecting the state of the wire electrode 1 is disposed slightly downstream of the power supply roller 17.
[0024]
In order to smoothly insert the tip of the wire electrode 1 supplied through the wire feed roller 4, the supply pipe 5 and the upper wire head 2 sequentially into the workpiece W, a die guide 8 provided on the upper wire head 2 is provided. The wire guide 50 is attached. Further, the wire electrode 1 is machined into the workpiece W while being guided through the supply pipe 5 and the inside of the upper wire head along the flow of air flowing in the feeding direction of the wire electrode 1 to the upper wire head 2 through the supply pipe 5. Supplied to the site.
[0025]
The supply pipe 5 through which the wire electrode 1 is inserted is attached to the head via a supply pipe holder 11 at the upper end portion thereof. The supply pipe holder 11 can be moved up and down together with the head in order to change the vertical position according to the height of the workpiece W. The supply pipe holder 11 has a through hole 21 through which the wire electrode 1 is inserted, a holder guide member 22 that is provided on the inlet side of the through hole 21 and guides the wire electrode 1, and a pipe mounting hole that receives the upper end portion 5 a of the supply pipe 5. 23 and a fluid passage 24 that is open to the through hole 21 and into which compressed air flows from the air supply source through the hose 25 and the connection plug 26 is formed. The holder guide member 22 has an end surface on the wire feed roller 4 side opened in a taper shape at a position immediately below the feed port of the wire feed roller 4, and the wire electrode 1 fed from the wire feed roller 4 is supplied to the supply pipe. This is a guide for smoothly feeding the holder 11. A guide piece 27 is attached to the lower end 5 b of the supply pipe 5. The guide piece 27 has a tapered tip, and faces the opening of the through hole 30 of the wire electrode 1 of the upper wire head 2.
[0026]
The upper wire head 2 has a substantially cylindrical shape, and a through hole 30 is formed through the center in the vertical direction. A die guide mounting hole 31 is continuously formed concentrically below the through hole 30. A pair of guide pieces 32 and 33 are arranged to face each other at the upper end of the through hole 30 and the connecting portion between the through hole 30 and the die guide mounting hole 31. A power supply 10 for supplying a current to the wire electrode 1 is disposed at a central position in the vertical direction of the through hole 30. The guide pieces 32 and 33 and the power supply 10 occupy the positions shown in the figure when the wire electrode 1 is supplied. However, when the tip of the wire electrode 1 is fed, the wire electrode 1 is used to avoid interference with the tip. It is possible to retreat from the travel route to the position indicated by the imaginary line.
[0027]
A die guide 8 is mounted in the die guide through hole 31 of the upper wire head 2 continuously to the guide piece 33. Further, in order to inject water as a working fluid supplied from the outside of the upper wire head 2 from the jet nozzle 9, there is an annular passage 34 inside the upper wire head 2 and a lower end extending in the axial direction from the annular passage 34. Are formed, and an axial passage 35 is formed, and a radial passage 36 extending from the outer wall of the upper wire head 2 and connected to the annular passage 34 is formed. The machining fluid is supplied to the radial passage 36 from the machining fluid supply source through the hose 37 and the connection plug 38. The jet nozzle 9 is formed in a tapered cone shape so as to concentrically cover the protruding end portion of the die guide 8. The machining fluid sprayed from the axial passage 35 is sprayed from the wire delivery port 7 so as to follow the traveling direction of the wire electrode 1 through the cone-shaped spray passage 39. In the workpiece W, a machining slit (including a start hole) A through which the wire electrode 1 is inserted is formed. A slight gap 42 is formed between the upper surface 41 of the workpiece W and the lower surface of the jet nozzle 9, and the machining liquid ejected from the jet nozzle 9 passes through the machining slit A and the gap 42 and is processed. It flows out into the tank 6.
[0028]
FIG. 2 shows a cross-sectional view of a die guide 8 provided in the upper wire head 2 in the wire feeder in the wire electric discharge machine according to the present invention. The die guide 8 is formed of a cylindrical main body 43 and a tip 44 on the tip side. The die guide 8 is made of stainless steel, for example. A hollow hole 45 is formed inside the die guide 8, and a female screw 46 that engages with a male screw of a pressing member that holds the guide piece 32 is formed on the inner wall that defines the hollow hole 45. The front end side of the hollow hole 45 is a tapered guide portion 47 and is connected to the through hole 48 having the smallest diameter. A wire guide mounting hole 49 for mounting the wire guide 50 is formed in the tapered portion 44 so as to be connected to the through hole 48. Note that a tool engaging portion 44a is formed in the tapered portion 44 by cutting out a part of its outer surface. By rotating the die guide 8 with the tool engaged with the tool engaging portion 44a, the screw engagement with the pressing member for pressing the guide piece 32 can be engaged and disengaged. In addition, a hole communicating with the tapered guide portion 47 is opened in the tool engaging portion 44 a so that a part of the machining liquid supplied to the hollow hole 45 flows into the cone-shaped injection passage 39. it can.
[0029]
The wire guide 50 includes a taper-shaped wire guide member 51 disposed on the upstream side in the feeding direction of the wire electrode 1 and a straight wire guide disposed on the downstream side in the feeding direction of the wire electrode 1 at the outlet of the die guide 8. It comprises a member 52 and a wire guide member 53 sandwiched between a tapered wire guide member 51 and a straight wire guide member 52. The tapered wire guide member 51 has a tapered tapered guide hole 54 having a central axis that coincides with the central axis of the hollow hole 45. The straight wire guide member 52 has a straight guide hole 55 having a central axis coinciding with the central axis of the hollow hole 45 inside. The wire guide member 53 has a guide hole 56 that defines a minimum diameter in the wire guide 50. The hole diameter of the straight guide hole 55 is set slightly larger than the hole diameter of the guide hole 56 of the wire guide member 53. The tapered wire guide member 51 and the straight wire guide member 52 are formed of an insulator such as sapphire, ruby or ceramic. The wire guide member 53 can be made of diamond, but can also be made of a material such as sapphire similar to the tapered wire guide member 51 and the straight wire guide member 52.
[0030]
The wire guide member 53 is held between the outside and the wire guide mounting hole 49 so as not to be displaced in the radial direction by the holding member 57. The tapered wire guide member 51, the straight wire guide member 52, and the holding member 57 are sequentially press-fitted into the wire guide mounting hole 49, and the tapered wire guide member 51 contacts the stepped portion 49 a of the wire guide mounting hole 49. It is pushed in and attached in the state.
[0031]
Next, the operation of the wire feeder in this wire electric discharge machine will be described. At the beginning of driving the wire electric discharge machine, the wire electrode 1 fed into the feed roller 14 is guided by a holder guide member 22 that opens in a tapered shape of the supply pipe holder 11 and enters the through hole 21 of the supply pipe holder 11. And is guided from the supply pipe holder 11 into the supply pipe 5. When the tip of the wire electrode 1 descends in the through hole 21 of the supply pipe holder 11, compressed air as a guide fluid is flowed from the air supply source into the through hole 21 and the supply pipe 5 through the fluid passage 24. The air flow guides the wire electrode 1 so that the end of the wire electrode 1 moves straight down in the supply pipe 5 without sideways shaking. Note that the wire electrode 1 is subjected to an annealing process by passing an electric current through the wire electrode 1 passed between the feed roller 14 and the power supply roller 17 as an annealing roller in order to correct the bending wrinkle when rewinding from the source bobbin. Is sent to. When the wire electrode 1 is initially set or the wire electrode 1 is cut, the end of the wire electrode 1 is cut by the cutter 16. In Accordingly, a new tip is formed on the wire electrode 1 by cutting.
[0032]
The distal end portion of the wire electrode 1 is introduced into the upper wire head 2 from a guide piece 27 attached to the lower end portion 5 b of the supply pipe 5. In the upper wire head 2, the guide pieces 32, 33 and the feeder 10 occupy the retracted position so that the tip of the wire electrode 1 can be easily lowered and passed when the tip of the wire electrode 1 is inserted. Yes. Even in the upper wire head 2, the air blown from the supply pipe 5 is introduced into the upper wire head 2 when air is supplied in order to guide the tip of the wire electrode 1 without lateral shaking. In order to prevent the air from the supply pipe 5 from leaking to the outside, the tapered tip end portion of the guide piece 27 is brought into pressure contact with the guide piece 32 of the upper wire head 2. The wire electrode 1 descends in the through hole 30 of the upper wire head 2 without interfering with the guide pieces 32 and 33 and the power supply 10, and reaches the die guide 8.
[0033]
In the die guide 8, the tip of the wire electrode 1 is sequentially guided through the hollow hole 45 formed in the cylindrical main body 43, the tapered guide portion 47, and the through hole 48 while being guided by the air flow. 50. In the wire guide 50, the distal end portion of the wire electrode 1 is inserted into the guide hole 56 of the wire guide member 53 while being guided by the taper-shaped guide hole 54 and the air flow. Since the air flow is strongest in the guide hole 56, the distal end portion of the wire electrode 1 can be accurately inserted into the straight guide hole 55 of the straight wire guide member 52 even if the guide hole 56 has the smallest diameter. Guided. Although the diameter of the straight guide hole 55 is larger than that of the guide hole 56, the diameter of the straight guide hole 55 is smaller than that of the hollow hole 45 and the through hole 48, and the air flow is sufficiently strong. The guide hole 55 is guided straight.
[0034]
The tip end portion of the wire electrode 1 guided by the guide hole 56 of the wire guide member 53 is guided as it is without being laterally shaken by the straight guide hole 55 of the straight wire guide member 52, so that the machining slit A of the workpiece W is obtained. Is sent to. Since the wire guide member 52 disposed on the outlet side of the wire guide member 53 does not have a guide hole enlarged in a tapered shape as in the prior art, the tip of the wire electrode 1 is connected to the straight guide hole 55. As is, it can be smoothly guided to the small or narrow machining slit A of the workpiece W. The tip of the wire electrode 1 is further inserted into the lower wire head 3 from the machining slit A of the workpiece W, and then, although not shown, a drawing roller 65 (see FIG. 5) provided outside the machining tank 6. ) And discharged to a waste wire hopper. During the operation of the wire electric discharge machine, the wire electrode 1 is continuously drawn by the drawing roller 65, so that the air action from the air supply source may be invalidated. Of course, the guide action by the air flow may be slightly functioned only in the supply pipe 5 away from the guide piece 32 of the upper wire head 2.
[0035]
Since the supply of the tip portion of the wire electrode 1 uses guidance by the flow of air, it is preferable that the processing liquid is not supplied to the processing tank 6 at least up to the water level of the workpiece W. When the insertion of the wire electrode 1 to the lower wire head 3 is completed, the guide pieces 32 and 33 are advanced to guide the wire electrode 1, and the feeder 10 is brought into sliding contact with the wire electrode 1 to supply current. Let Water as a machining liquid is injected into the machining tank 6, and further, when the workpiece W is subjected to electric discharge machining, a hose 37, a plug 38, a radial passage 36 formed in the upper wire head 2, and an annular shape from the machining liquid supply source. Water is jetted from the jet nozzle 9 through the passage 34 and the axial passage 35. The machining liquid injected from the outside through the axial passage 35 is injected from the wire delivery port 7 so as to follow the traveling direction of the wire electrode 1 through the cone-shaped injection passage 39 of the jet nozzle 9. A machining slit A through which the wire electrode 1 is inserted is formed in the workpiece W. A slight gap 42 is formed between the upper surface 41 of the workpiece W and the lower surface of the jet nozzle 9, and the machining liquid ejected from the jet nozzle 9 passes through the machining slit A and the gap 42 and is processed. It flows out into the tank 6. The wire electrode 1 performs electric discharge machining on the workpiece W disposed between the upper wire head 2 and the lower wire head 3 in the machining liquid accommodated in the machining tank 6, but the straight shape of the straight wire guide member 52. Since the guide hole 55 is not a tapered guide hole like a conventional wire guide, the workpiece W cannot be tapered.
[0036]
【The invention's effect】
As described above, the wire feeding device in this wire electric discharge machine has a tapered wire guide member disposed on the inlet side of the through hole of the upper wire head and having a tapered tapered guide hole. A straight wire guide member disposed on the outlet side of the through hole of the wire head and having a straight guide hole, and a taper guide hole and the straight guide sandwiched between the taper wire guide member and the straight wire guide member Since the wire guide member has a guide hole with the smallest diameter communicating with the hole, the tip of the wire electrode is guided by the tapered taper guide hole of the taper wire guide member in the wire guide, and then the wire Guided by the guide hole with the smallest diameter of the guide member, and further, the straight wire guide member Is guided by the traits shaped guide hole, it is introduced into the processing region of the workpiece. Since the wire guide member disposed on the outlet side of the wire guide does not have a front opening taper hole unlike the conventional wire guide, the wire guide member is raised and lowered with respect to the supply pipe held in a suspended state by the head and the head. The wire electrode supplied through the upper wire head that can be attached is accurately guided to the machining slit of the workpiece placed between the upper wire head and the lower wire head, so that the lower wire head Introduced against.
[0037]
In addition, the wire feeding device in this wire electric discharge machine guides the supply of the wire electrode by the flow of air in the supply pipe. air Thus, the wire electrode can be surely passed through such a narrow passage. In addition, air is supplied not only when the tip of the wire electrode is introduced, but also during normal feeding of the wire electrode, thereby preventing the occurrence of feeding resistance due to bending of the wire electrode. Even if a wire electrode with a smaller size than a general size is used, the wire electrode, particularly its tip, penetrates the upper wire head without being obstructed by using the air flow characteristics. The holes, the die guide, the wire guide, and the workpiece are sequentially fed, so that the wire electrode can be inserted and supplied reliably and smoothly.
[Brief description of the drawings]
FIG. 1 is a schematic explanatory view showing an embodiment of a wire feeding device in a wire electric discharge machine according to the present invention.
2 is a cross-sectional view showing a die guide of a wire feeder in the wire electric discharge machine shown in FIG.
FIG. 3 is an end view of the die guide shown in FIG. 2;
4 is an enlarged view showing a wire guide provided in the die guide shown in FIG. 2. FIG.
FIG. 5 is a schematic front view showing a part of a start hole guide type automatic wire feeder.
FIG. 6 is a longitudinal sectional view of a conventional die guide.
7 is an end view of the die guide shown in FIG. 6. FIG.
8 is a cross-sectional view of a wire guide disposed at the tip of the die guide shown in FIG.
[Explanation of symbols]
1 Wire electrode
2 Upper wire head
3 Lower wire head
5 Supply pipe
11 Supply pipe holder
21 Holder through hole
24 Fluid passage
30 Through hole
50 wire guide
51 Tapered wire guide member
52 Straight wire guide member
53 Wire guide members
54 Tapered wire guide hole
55 Straight wire guide hole
56 Guide hole
W Workpiece

Claims (4)

A supply pipe held in a suspended state by the head, an upper wire head attached to the head so as to be movable up and down at a position below the supply pipe, and an upper wire head provided facing the upper wire head, A lower wire head in which a workpiece is disposed between the wire electrode and a wire electrode fed from a wire electrode supply source to the supply pipe, the upper wire head, a hole formed in the workpiece and the lower wire head. In a wire electric discharge machine that is sequentially penetrated and provided with a wire guide for guiding the wire electrode to the hole of the workpiece on the exit side of the through hole of the upper wire head, the wire guide includes: A tapered wire guide provided on the upstream side in the feeding direction of the wire electrode and having a tapered tapered guide hole connected to the through hole. Material, a straight wire guide member provided on the downstream side in the feeding direction of the wire electrode and having a straight guide hole, and the taper guide hole sandwiched between the taper wire guide member and the straight wire guide member And a wire guide member having a guide hole with a minimum diameter communicating with the straight guide hole. A wire feeding device in a wire electric discharge machine. The wire feeding device in the wire electric discharge machine according to claim 1, wherein air is supplied to the supply pipe in the feeding direction of the wire electrode at least when the tip of the wire electrode is fed. The supply pipe is held at the upper end of the supply pipe by a head through a supply pipe holder. The supply pipe holder has a holder through hole that is connected to the supply pipe in a straight line and through which the wire electrode passes. The wire feeding device in the wire electric discharge machine according to claim 2 , wherein a fluid passage that is connected to the holder through-hole from the side and into which the air is fed is formed. The wire discharge according to any one of claims 1 to 3, wherein the tapered wire guide member and the straight wire guide member are formed of an insulator such as sapphire, ruby, or ceramic. Wire feeding device in a processing machine.

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