JP2000005934A - Wire feeding device for wire electrical discharge machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a wire feeding device for a wire electrical discharge machine in which guiding of the end of a wire electrode into a workpiece is ensured by straightening a guide hole in the downstream wire guide member of a wire guide assembled into an upper wire head. SOLUTION: A wire guide 50 assembled into an upper wire head comprises a tapered wire guide member 51 placed on the upstream side along the direction to extend a wire electrode 1, a wire guide member 53 having a guide 56 of minimum diameter, and a straight wire guide member 52 placed on the downstream side along the direction to extend the wire electrode 1. Since the straight wire guide member 52 has a straight guide hole 55, the wire electrode 1, particularly its end, is guided directly downward along the straight guide hole 55 and surely and smoothly passed through a hole formed for machining a workpiece.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wire feeder in a wire electric discharge machine for processing a workpiece by generating a discharge phenomenon between a wire electrode and the workpiece.

[0002]

2. Description of the Related Art A wire electric discharge machine is a machine tool for generating a discharge phenomenon between a wire electrode and a workpiece to cut out a workpiece such as cemented carbide or hardened steel. When starting electric discharge machining, a wire electrode is inserted in advance into a start hole (machining start hole) drilled in a workpiece. When a voltage is applied between the wire electrode and the workpiece, which is constantly supplied, and the workpiece is discharged, the workpiece W is subjected to electrical discharge machining by a discharge energy into a predetermined machining shape. Processing of workpiece is N
The workpiece is controlled by the C device, and a continuous slit is formed in the workpiece according to the shape programmed in the NC device.

[0003] When the processing of a workpiece is completed and processing of another workpiece is started, or when the wire electrode is broken during electric discharge machining, the tip of the wire electrode is cut off and removed to form a newly formed wire electrode. The wire electrode is set by inserting the tip end into the machining slit including the start hole of the workpiece. As a part of the automation of the electric discharge machining work, the work of mounting the wire electrode from sending out the wire electrode to cutting the wire electrode and reinserting it into the machining slit is automated.

FIG. 5 is a view showing an automatic wire supply apparatus of an annealing dry supply type in which a wire electrode which has been straightened by annealing (annealing) is passed through a start hole without using a water flow. As shown in FIG. 5, the automatic wire feeder supplies various types of direction change rollers 61, tension rollers 62, and brake rollers to supply the wire electrode 1 fed from the source bobbin 60 to the processing slit (including the start hole) A. 63, a direction changing roller 64, a drawing roller 65 and the like. The drawn-out wire electrode 1 is taken up on 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 by the upper wire head 66 and the lower wire head 67, the wire electrode 1
The vehicle runs accurately on the workpiece W between the two heads while restricting the lateral runout. The lower wire head 67
It is supported by the tip of a lower arm attached to the head so as to hang down from above the processing tank, and has a direction change roller 64 inside. In the downstream of the lower wire head 67, a drawing device such as a pair of drawing rollers 65 for drawing the wire electrode 1 through the guide pipe and making the wire electrode 1 in a tensioned state is attached to the outside of the processing tank. The wire electrode 1 that has been subjected to the annealing process and has been straightened is inserted into the start hole of the workpiece W from its tip. In addition, as this kind of automatic wire feeding device,
For example, there is one described in JP-A-2-145215.

[0005] The workpiece W is mounted on the upper wire head 3 facing the workpiece.
In a state installed between the lower wire head 6 and the lower wire head 37, it is fixed to the processing tank by a suitable clamping means or supporting means. The electric discharge machining for the workpiece W is performed in a state where the workpiece W is immersed in a machining fluid filled in a machining tank. The processing tank is driven in accordance with the processing 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 a Y-axis servo motor on the bed base, and the X-axis table with the processing tank is driven in the X-axis direction by the X-axis servo motor on the Y-axis table.

Wire electrodes of various sizes and materials are available for the wire electrodes. Usually, in a wire electric discharge machine, a wire electrode of brass and a wire diameter of φ0.2 is used. 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, when a high precision machining accuracy such as about 0.1 mm is required for the slit width or the minimum corner radius in a wire electric discharge machine, a thin wire electrode having a diameter smaller than that is used. . A thin wire electrode having a diameter of about 0.1 or less has a lower stiffness than a wire electrode of a conventional size, and is likely to bend or swing. Therefore, a guide having a tapered surface is employed so that the thin wire electrode is guided even if it is not straightened.

A die guide provided on the upper wire head and guiding the wire electrode 1 to a start hole of a workpiece and a conventional wire guide used for the die guide have a structure as shown in FIGS. ing. 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 provided 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 a female screw 86 for connecting to another guide member is formed on the inner peripheral surface of the hollow hole 85. Hollow hole 8
Reference numeral 5 denotes a through hole of the die guide 80 which communicates 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 a wire guide 90 is formed at the tip side of the through hole 88. The wire guide mounting hole 89 includes a small-diameter portion and a large-diameter portion whose diameter becomes gradually larger than the diameter of the through hole 88. The taper 84
The tool engaging portion 84a
Are formed.

[0008] As shown in FIG.
It is composed of a diamond wire guide member 93 made of diamond, and a pair of tapered wire guide members 91 and 92 for sandwiching the diamond wire guide member 93 on both the upstream and downstream sides in the feeding direction of the wire electrode 1. Tapered wire guide members 91, 92
Is manufactured from insulating materials such as ruby, sapphire, ceramics, and the like. 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 sandwiched by a pair of tapered wire guide members 91 and 92,
It is mounted on the wire guide mounting part 89. That is, the tapered wire guide member 91 on the upstream side, 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 part on the exit side of. Tapered wire guide member 91
Has a tapered guide hole 94 having a central axis that is tapered toward the downstream side of the feeding of the wire electrode 1 and coincides with the central axis of the through hole 88, and passes through the hollow hole 85 and the through hole 88. The leading end of the guided wire electrode 1 is guided so as 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 feeding of the wire electrode 1 also has a tapered opening toward the downstream side of the feeding of the wire electrode 1 and a through-hole for processing the workpiece W into a tapered surface. A tapered guide hole 95 having a central axis coinciding with the central axis of 88
have. That is, when the workpiece is machined 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 in a tapered guide hole 95 which is formed in a tapered shape at an exit side of about 90 °.

[0010]

By the way, in a wire electric discharge machine, when a wire electrode having a diameter smaller than the usually used φ0.2, for example, a diameter of about 0.1 or less, is used. The wire electrode is easy to bend even if it is straightened by applying an annealing treatment. In the wire electrode insertion process of inserting the wire electrode into the workpiece, the wire electrode bends easily as the feeding amount becomes longer, and the operating rate of the automatic wire electrode supply device Decrease. In particular, in the long supply path of the wire electrode from the wire feed roller to the upper wire head,
In order to prevent bending of the wire electrode, a wire supply pipe for guiding the wire electrode inside is provided. However, even if such a wire supply pipe is provided, the position of the tip of the very fine wire electrode becomes unstable, and if there is an inconvenience such as the tip of the wire electrode fluctuating in the supply pipe, the wire electrode is placed at that position. Accumulates and the wire electrode cannot be fed smoothly in the supply pipe.
It is difficult to pay out stably to the upper wire head.

In the above 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 of penetrating the wire electrode through the start hole is low. Since it is more difficult to penetrate a wire electrode through a narrow processing slit, the wire electrode is once passed through a start hole having a large diameter, and then the wire electrode is advanced again along a processing locus which has already been formed. Work to advance the electrode to the processing start point was required. For this reason, the wire electrode insertion work with a large time loss has caused the electric discharge machining work to be inefficient.

Also, the conventional tapered wire guide member 9
As shown in FIGS. 6 to 8, the diamond wire guides 1 and 92 have a tapered wire guide member 92 on the downstream side in the feeding direction of the wire electrode 1 having a tapered surface opened on the downstream side. When the ultrafine wire electrode 1 guided by the member 93 exits the wire guide 90, the position of the distal end of the wire electrode 1 becomes unstable and may swing back and forth and right and left. 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 processing slits are close to each other, there is a possibility that the slit enters a neighboring start hole or the like.

Therefore, in the above-described wire electric discharge machine, even when the wire electrode is automatically supplied using a fine wire electrode, the wire electrode fed by the feed roller is supplied from the supply pipe to the upper wire head and to the wire guide. However, there is still a problem to be solved in that it can be accurately and smoothly introduced into a machining slit of a workpiece.

[0014]

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems, and even if a wire electrode having a smaller size than a general size is used,
An object of the present invention is to provide a wire feeder in a wire electric discharge machine capable of capturing a wire electrode without obstructing the progress thereof and penetrating the wire guide on a downstream side or a machining slit of a workpiece with a high success rate.

According to the present invention, there is provided a supply pipe held down 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 to face the upper wire head. And a lower wire head on which a workpiece is disposed between the upper wire head and the upper wire head. A wire electrode fed from a wire electrode supply source is formed on the supply pipe, the upper wire head, and the workpiece. In a wire electric discharge machine, a wire guide is provided to sequentially penetrate a hole and the lower wire head, and a wire guide for guiding the wire electrode to the hole of the workpiece is provided at an exit side of the through hole of the upper wire head. The wire guide has a tapered tapered guide hole provided upstream of the wire electrode in the feeding direction and connected to the through hole. A tapered wire guide member, a straight wire guide member provided downstream of the wire electrode in the feeding direction and having a straight guide hole, and sandwiched between the tapered wire guide member and the straight wire guide member; The present invention relates to a wire feeder in a wire electric discharge machine, comprising a wire guide member having a guide hole having a minimum diameter communicating the tapered guide hole and the straight guide hole.

In the wire feeder of this wire electric discharge machine, air is supplied to the supply pipe at least at the time of feeding out the distal end portion of the wire electrode in the wire feeding direction. Due to the guiding action of the wire electrode by air, the wire electrode is guided to the first die guide of the upper wire head.

The supply pipe is held at its upper end by a supply pipe holder via a supply pipe holder. The supply pipe holder is connected directly to the supply pipe and the wire electrode passes through the supply pipe holder. A holder through hole and a fluid passage connected to the holder through hole from the side and into which the air is sent are formed.

Further, the tapered wire guide member and the straight wire guide member are formed of an insulator such as sapphire, ruby, ceramics and the like.

In the wire feeder of this wire electric discharge machine, as described above, the wire guide disposed on the exit side of the through hole of the upper wire head is provided on the upstream side in the wire electrode feeding direction and the upper side. Tapered wire guide member having a tapered tapered guide hole connected to a through hole of a wire head, straight wire guide member provided on the downstream side in the wire electrode feeding direction and having a straight guide hole, and tapered wire guide Since it is composed of a wire guide member sandwiched between the member and the straight wire guide member and having a guide hole having a minimum diameter communicating the tapered guide hole and the straight guide hole, the wire guide member is fed from the wire electrode supply source. The tip of the wire electrode introduced from the supply pipe into the through hole of the upper wire head is The tapered guide hole of the tapered wire guide member and the guide hole of the wire guide member having the smallest diameter guide hole are inserted while being sequentially guided. Guided straight through the hole formed in the workpiece placed between the upper and lower wire heads without swinging into the hole, and successfully inserted into the hole formed in the workpiece with high probability I do. In addition, by supplying air to the supply pipe, the tip of the wire electrode is guided by the air flow, and even if the wire electrode has a bend, the tip of the wire electrode is inserted into the hole formed in the workpiece. It is more accurately inserted.

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment 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 a wire feeder according to the present invention is applied, and FIG. 2 shows a wire head provided on an upper wire head and its holder in the wire electric discharge machine of FIG. FIG. 3 is a longitudinal sectional view, FIG. 3 is an end view of the wire head and its holder shown in FIG. 2, and FIG. 4 is a sectional view showing a wire guide provided on the upper wire head shown in FIG. It should be noted that the automatic wire feeder having the structure shown in FIG. 5 can be employed.

In this wire electric discharge machine, for example,
The head (see FIG. 5) constituting the main body of the processing machine includes an upper wire head 2 for guiding the wire electrode 1 to the electric discharge machining site of the workpiece W, and a lower arm (see FIG. 5) which hangs down into the processing tank 6. A lower wire head 3 disposed opposite the upper wire head 2 via a lower arm case or housing 13 provided at the distal end is attached. The lower wire head 3 receives the wire electrode 1 that has undergone electrical discharge machining on the workpiece W. The head has a pair of wire feed rollers 4 for feeding the wire electrode 1 with the wire electrode 1 interposed therebetween, a supply pipe 5 through which the wire electrode 1 penetrates an internal passage, and a guide for the wire electrode 1. Devices, such as rollers, are provided.

The upper wire head 2 includes a wire outlet 7, a die guide 8, a jet nozzle 9,
The power supply 10 and the like are incorporated. Feed roller 14 rotatably supported by housing 13 of lower wire head 3
Guides the wire electrode 1 by changing its direction. In the downstream of the lower wire head 3, a pulling device such as a pair of pull-out rollers (65, see FIG. 5) for pulling out the wire electrode 1 and tensioning the wire electrode 1 is applied to a support member provided outside the processing tank 6. Installed. Also, the lower wire head 3
A sensor (not shown) or the like for detecting that the wire electrode 1 is inserted into the lower wire head 3 is provided, and the tip of the wire electrode 1 is inserted into the processing slit A of the workpiece W or the lower wire head 3. If not, a detection signal of a supply failure is transmitted to the controller. The processing liquid is filtered and reused by a filtering device laid in the processing tank 6.

The wire feed roller 4 also serves as an annealing roller, and can move up and down with respect to the head. In addition, a pair of power supply rollers 17 are provided below the supply pipe 5 to supply current for annealing to the wire electrode 1 extending between the wire feed roller 4 and the wire electrode 1. Slightly upstream of the feed roller 17 is a cutter 16 for cutting the wire electrode 1 to form a new tip.
Are arranged. Further, a photoelectric sensor 18 for detecting the state of the wire electrode 1 is provided slightly downstream of the power supply roller 17.

The wire electrode 1 supplied sequentially through the wire feed roller 4, the supply pipe 5, and the upper wire head 2
A wire guide 50 is attached to the die guide 8 provided on the upper wire head 2 so that the tip of the die W can be smoothly inserted into the workpiece W. The wire electrode 1 is guided through the supply pipe 5 and the inside of the upper wire head along the flow of air flowing in the feed direction of the wire electrode 1 to the upper wire head 2 through the supply pipe 5.
Is supplied to the processing part.

The supply pipe 5 through which the wire electrode 1 is inserted is
At its upper end, it is attached to the head via a supply pipe holder 11. The supply pipe holder 11
In order to be able to change the position in the vertical direction according to the height of the workpiece W, it can be moved up and down together with the head. The supply pipe holder 11 has a through hole 21 through which the wire electrode 1 is inserted, a holder guide member 22 provided at the entrance side of the through hole 21 to guide the wire electrode 1, and a pipe mounting hole for receiving the upper end 5 a of the supply pipe 5. 23, and a fluid passage 24 that opens to the through hole 21 and through which compressed air flows from an air supply source through a hose 25 and a connection plug 26 is formed. The holder guide member 22 has an end surface on the wire feed roller 4 side tapered at a position immediately below the feed port of the wire feed roller 4.
The wire electrode 1 fed from the supply pipe holder 11
It is a guide to supply the water smoothly. A guide piece 27 is attached to the lower end 5 b of the supply pipe 5. The tip of the guide piece 27 is formed in a tapered shape, and faces the opening of the through hole 30 of the wire electrode 1 of the upper wire head 2.

The upper wire head 2 has a substantially cylindrical shape, and has a through hole 30 penetrating vertically through the center thereof. A die guide mounting hole 31 is formed concentrically and continuously below the through hole 30. Through hole 3
The pair of guide pieces 32,
33 are provided facing each other. A power supply 10 for supplying a current to the wire electrode 1 is provided 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 illustrated positions 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. From the traveling route of the vehicle to the position shown by the imaginary line.

Die guide through hole 3 of upper wire head 2
1 includes a die guide 8 following the guide piece 33.
Is installed. Further, since water as a processing liquid supplied from the outside of the upper wire head 2 is jetted from the jet nozzle 9, an annular passage 34 is provided inside the upper wire head 2.
And an axial passage 35 extending axially from the annular passage 34 and opening at the lower end, and a radial passage 36 extending from the outer wall of the upper wire head 2 and connecting to the annular passage 34. The radial passage 36 is provided with a hose 37 from a machining fluid supply source.
The working fluid is supplied through the connection plug 38. The jet nozzle 9 is formed in a tapered cone shape so as to concentrically cover the projecting end of the die guide 8. The machining fluid injected from the axial passage 35 is supplied to the cone-shaped injection passage 39.
The wire is ejected from the wire outlet 7 so as to pass along the traveling direction of the wire electrode 1. The workpiece W has a wire electrode 1
A processing slit (including a start hole) A through which is inserted is formed. A gap 42 is slightly formed between the upper surface 41 of the workpiece W and the lower surface of the jet nozzle 9, and the machining fluid ejected from the jet nozzle 9 passes through the machining slit A and the gap 42 to be machined. It flows into the inside of the tank 6.

FIG. 2 is a sectional view of a die guide 8 provided on the upper wire head 2 in the wire feeder in the wire electric discharge machine according to the present invention. The die guide 8 includes a cylindrical main body 43 and a tapered portion 4 on the tip end side.
4 is formed. The die guide 8 is made of, for example, stainless steel. A hollow hole 45 is formed inside the die guide 8, and an inner wall defining the hollow hole 45 has:
A female screw 46 is formed which engages with a male screw of a holding member for holding the guide piece 32. The distal end side of the hollow hole 45 is a tapered guide portion 47 to form a through hole 48 having a minimum diameter.
Connected to. In the tapered portion 44, a wire guide mounting hole 49 for mounting the wire guide 50, which is slightly larger in diameter than the through hole 48, is formed so as to be connected to the through hole 48. The tapered portion 44 has a tool engaging portion 44a formed by cutting out a part of the outer surface. The die guide 8 is formed by the tool engaged with the tool engagement portion 44a.
The screw engagement with the holding member that holds the guide piece 32 can be disengaged by rotating the. Further, a hole communicating with the tapered guide portion 47 may be opened in the tool engagement portion 44a, and a part of the machining fluid supplied to the hollow hole 45 may flow into the cone-shaped injection passage 39. it can.

At the outlet of the die guide 8, the wire guide 50 is provided with a tapered wire guide member 51 disposed upstream of the wire electrode 1 in the feeding direction and a straight wire guide member 51 disposed downstream of the wire electrode 1 in the drawing direction. It comprises a wire guide member 52 and a wire guide member 53 sandwiched between the tapered wire guide member 51 and the straight wire guide member 52. The tapered wire guide member 51 has a tapered tapered guide hole 54 having a central axis coinciding with the central axis of the hollow hole 45. The straight wire guide member 52 has a hollow hole 45 inside.
And a straight guide hole 55 having a central axis coinciding with the central axis. 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 or the straight wire guide member 52.

The wire guide member 53 is held by a holding member 57 between the outside thereof and the wire guide mounting hole 49 so as not to be displaced in the radial direction. The tapered wire guide member 51, the straight wire guide member 52, and the holding member 57 are sequentially pressed into the wire guide mounting hole 49, and the tapered wire guide member 51 comes into contact with the step portion 49a of the wire guide mounting hole 49. It is attached in a state where it is pushed down.

Next, the operation of the wire feeder in this wire electric discharge machine will be described. When the wire electric discharge machine is started to be driven, the wire electrode 1 sent to the feed roller 14 is guided by the tapered holder guide member 22 of the supply pipe holder 11 and is fed into the through hole 21 of the supply pipe holder 11. , And further guided from the supply pipe holder 11 into the supply pipe 5. When the distal end of the wire electrode 1 descends in the through hole 21 of the supply pipe holder 11, compressed air as a guide fluid flows from the air supply source into the through hole 21 and the supply pipe 5 through the fluid passage 24. The flow of air guides the wire electrode 1 so that the end of the wire electrode 1 descends straight in the supply pipe 5 without swaying. Note that the wire electrode 1 is provided with a feed roller 1 as an annealing roller to correct a bending habit when unwinding from the source bobbin.
After passing an electric current through the wire electrode 1 passed between the feed roller 4 and the power supply roller 17 to perform an annealing process, the wire electrode 1 is fed.
When the initial set of the wire electrode 1 or the wire electrode 1 is cut, a new tip is formed on the wire electrode 1 by cutting the end of the wire electrode 1 with the cutter 16.

The tip of the wire electrode 1 is introduced into the upper wire head 2 from a guide piece 27 attached to the lower end 5b of the supply pipe 5. In the upper wire head 2, when the distal end of the wire electrode 1 is inserted, the guide pieces 32, 33 and the power supply 10 occupy the retracted positions so that the distal end of the wire electrode 1 straightly descends and passes easily. I have. In order to guide the distal end portion of the wire electrode 1 in the upper wire head 2 without swaying, the air blown out from the supply pipe 5 is introduced into the upper wire head 2 when supplying air. In order to prevent the air from the supply pipe 5 from leaking outside, the tapered tip of the guide piece 27 is attached to the guide piece 32 of the upper wire head 2.
Is pressed against. The wire electrode 1 descends through the through hole 30 of the upper wire head 2 without interfering with the guide pieces 32, 33 and the power supply 10, and reaches the die guide 8.

In the die guide 8, the wire electrode 1
Of the cylindrical body 4 while being guided by the flow of air.
3, a hollow hole 45, a tapered guide portion 47
And through the through hole 48 to reach the inside of the wire guide 50. In the wire guide 50, the tip of the wire electrode 1 is
The tapered wire guide member 51 is inserted into the guide hole 56 of the wire guide member 53 while being guided by the tapered guide hole 54 and the flow of air. Since the flow of air is the strongest in the guide hole 56, the tip of the wire electrode 1 is 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. You will be guided. Straight guide hole 5
Although the hole diameter of the wire electrode 1 is larger than that of the guide hole 56, it is smaller than the hollow hole 45 and the through hole 48 and the air flow is sufficiently strong. You will be guided straight.

The distal end of the wire electrode 1 guided by the guide hole 56 of the wire guide member 53 is guided by the straight guide hole 55 of the straight wire guide member 52 without lateral deflection.
Into the processing slit A. Wire guide member 5
3, the wire guide member 52 disposed on the outlet side is
Since there is no tapered guide hole as in the prior art, the tip of the wire electrode 1 can be smoothly guided from the straight guide hole 55 to the small or narrow machining slit A of the workpiece W as it is. Can be. The tip of the wire electrode 1 is further inserted into the lower wire head 3 from the processing slit A of the workpiece W, and then, although not shown, a pull-out roller 65 provided outside the processing tank 6 (see FIG. 5). ) And is discharged to a waste wire hopper. During the operation of the wire electric discharge machine, the wire electrode 1 is continuously pulled out by the pull-out roller 65.
The action of air from the air supply source may be nullified, but in some cases, the tapered tip of the guide piece 27 is separated from the guide piece 32 of the upper wire head 2 and only in the supply pipe 5 is air supplied. Needless to say, the guiding action by the flow may be made to function slightly.

Since the supply of the tip portion of the wire electrode 1 uses the guide by the flow of air, it is preferable that the supply of the processing liquid to the processing tank 6 is performed 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, 33 are advanced to guide the wire electrode 1, and the current is supplied by sliding the power supply 10 into contact with the wire electrode 1. Let it. Processing tank 6
Is supplied with water as a machining fluid, and at the time of electric discharge machining of the workpiece W, a hose 37 and a plug 3 are supplied from a machining fluid supply source.
8, radial passage 3 formed inside upper wire head 2
6. Water is jetted from the jet nozzle 9 through the annular passage 34 and the axial passage 35. The machining fluid ejected from outside through the axial passage 35 is ejected from the wire outlet 7 along the traveling direction of the wire electrode 1 through the cone-shaped ejection passage 39 of the jet nozzle 9. In the workpiece W,
A processing slit A through which the wire electrode 1 is inserted is formed. A gap 42 is slightly formed between the upper surface 41 of the workpiece W and the lower surface of the jet nozzle 9, and the machining fluid ejected from the jet nozzle 9 passes through the machining slit A and the gap 42 to be machined. It flows into the inside of the tank 6. The wire electrode 1
The workpiece W disposed between the upper wire head 2 and the lower wire head 3 in the machining fluid contained in the machining bath 6 is subjected to electrical discharge machining. The straight guide holes 55 of the straight wire guide member 52 are Since it is not a tapered guide hole like a conventional wire guide, the workpiece W cannot be tapered.

[0036]

As described above, in the wire feeder of this wire electric discharge machine, the wire guide is provided at the entrance side of the through hole of the upper wire head and has a tapered tapered guide hole. A wire guide member, a straight wire guide member disposed on the outlet side of the through hole of the upper wire head and having a straight guide hole, and a tapered guide sandwiched between the tapered wire guide member and the straight wire guide member. The wire electrode has a minimum diameter guide hole that communicates the hole and the straight guide hole.
In the wire guide, after being guided by the tapered tapered guide hole of the tapered wire guide member, guided by the guide hole of the minimum diameter of the wire guide member,
The guide is guided by the straight guide holes of the straight wire guide member and is introduced into the processing portion of the workpiece.
Since the wire guide member disposed on the outlet side of the wire guide does not have a tapered opening at the head unlike the conventional wire guide, the wire guide member is vertically moved with respect to the supply pipe held down by the head and the head. The wire electrode supplied through the upper wire head, which is mounted as possible, is guided accurately to the machining slit of the workpiece arranged between the upper wire head and the lower wire head, and is guided to the lower wire head. Introduced for.

In the wire feeder in this wire electric discharge machine, the supply of the wire electrode is guided by the flow of air in the supply pipe, so that the narrower the tip of the wire electrode is, the smaller the flow of the fluid is. And the wire electrode can be reliably passed through such a narrow passage. Further, the supply of air is performed not only at the time of introduction of the tip of the wire electrode but also at the time of normal feeding of the wire electrode, so that the occurrence of feed resistance due to the bending tendency of the wire electrode can be prevented. Even if the size of the wire electrode is smaller than the general size, the wire electrode, especially its tip, uses the air flow characteristics to
Without being obstructed from proceeding, the through-hole of the upper wire head, the die guide, the wire guide, and the workpiece are sequentially fed, and the insertion and supply of the wire electrode can be performed reliably and smoothly.

[Brief description of the drawings]

FIG. 1 is a schematic explanatory view showing one embodiment of a wire feeder in a wire electric discharge machine according to the present invention.

FIG. 2 is a 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;

FIG. 4 is an enlarged view showing a wire guide provided in the die guide shown in FIG.

FIG. 5 is a schematic front view showing a part of an automatic wire feeder of a start hole guide type.

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;

FIG. 8 is a cross-sectional view of a wire guide provided at the tip of the die guide shown in FIG.

[Explanation of symbols]

 DESCRIPTION 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 member 54 Tapered Wire guide hole 55 Straight wire guide hole 56 Guide hole W Workpiece

Claims (4)

[Claims] 1. A supply pipe held down by a head, an upper wire head attached to the head at a position below the supply pipe so as to be able to move up and down, and provided opposite to the upper wire head. A lower wire head on which a workpiece is disposed between the upper wire head and the upper wire head, wherein a wire electrode fed from a wire electrode supply source is provided on the supply pipe, the upper wire head, a hole formed in the workpiece, and In a wire electric discharge machine, a wire guide is provided to sequentially penetrate the lower wire head, and a wire guide for guiding the wire electrode to a hole of the workpiece is provided at an exit side of a through hole of the upper wire head. The wire guide is provided on the upstream side in the feeding direction of the wire electrode, and has a tapered tapered guide hole connected to the through hole. A wire guide member, a straight wire guide member provided downstream of the wire electrode in the feeding direction and having a straight guide hole, and the tapered wire guide member sandwiched between the tapered wire guide member and the straight wire guide member. A wire feeder in a wire electric discharge machine, comprising a wire guide member having a guide hole having a minimum diameter communicating the guide hole and the straight guide hole. 2. A wire feeder in a wire electric discharge machine according to claim 1, wherein air is supplied to the supply pipe at least at the time of feeding the tip of the wire electrode in the feeding direction of the wire electrode. apparatus. 3. The supply pipe is held at its upper end by a supply pipe holder via a supply pipe holder, and the supply pipe holder is connected directly to the supply pipe and the wire electrode passes through the supply pipe holder. The wire feeder in a wire electric discharge machine according to claim 1 or 2, wherein a holder through-hole and a fluid passage connected to the holder through-hole from the side and into which the fluid is fed are formed. 4. The tapered wire guide member and the straight wire guide member are formed of an insulator such as sapphire, ruby, ceramics, and the like. 5. A wire feeder in a wire electric discharge machine according to claim 1.