JPS6250251B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION In the present invention, a pair of machining fluid injection nozzles through which a wire electrode is inserted are opposed to each other, and intermittent voltage pulses are applied between the wire electrode and a workpiece interposed between both nozzles. The present invention also relates to a nozzle device for wire cut electric discharge machining which spouts pressurized machining fluid toward a machining section from both nozzles, and particularly to one having a jet guide means suitable for high-speed cutting.

In wire cut electric discharge machining, in order to perform high-speed machining, it is necessary to increase the machining fluid pressure, flow rate, and flow rate in the machining part to reduce the generation of bubbles in the machining part and the entrainment of air bubbles from the outside.
It is necessary to increase the flow of liquid in the machined part and keep the temperature low in order to prevent the occurrence of air discharge, to remove machined debris at high speed, and to prevent wire electrode breakage accidents. The present invention is a wire cut electric discharge machining nozzle that reduces the amount of machining fluid that leaks from the machining section to the outside through the machining groove, thereby increasing the machining fluid flow rate and pressure in the machining section, in order to enable high-speed machining. The purpose is to provide equipment.

In order to achieve this objective, in the present invention,
In the case where the pair of machining fluid injection nozzles are configured and arranged so that the machining fluid jetting pressure, flow rate, flow rate, etc. (hereinafter referred to as "machining fluid jetting pressure, etc.") are different from each other, the machining fluid is It is made of a flexible material in which a magnet made of a magnetic material that attracts the workpiece is embedded around one machining liquid injection nozzle on the side where the injection pressure etc. are set lower than the other, and in the vicinity of the nozzle. The machining fluid injection pressure, etc. rises from the other machining fluid injection nozzle, which is set higher than that of the one machining fluid injection nozzle, to the upper surface of the workpiece through the machining part machining gap and the machined machining groove. It is characterized by providing a pad having a machining fluid passage section through which the incoming machining fluid passes. Note that the one and the other machining fluid injection nozzles are used in a wire cut electric discharge machining device in which the wire electrode is updated while the axis of the machining part wire electrode between a pair of positioning guides substantially coincides with the horizontal line. , either nozzle on the left or right side of the workpiece may correspond to one or the other, but the wire electrode is connected in a state in which the axis of the wire electrode of the processing section between the pair of positioning guides substantially coincides with the vertical line. In a wire-cut electrical discharge machining device in which the machine moves for renewal, the machining fluid injection nozzle normally installed on the lower side of the workpiece is connected to the other side, that is, the machining fluid injection pressure is applied to one side (the nozzle on the upper side of the workpiece ) corresponds to a machining fluid injection nozzle that is set high.

The details of the present invention will be explained below with reference to embodiments shown in the drawings. 1 to 3 show an embodiment of the present invention. In FIG. 1, 1 is a wire electrode, 2,
Reference numeral 3 denotes an upper arm and a lower arm to which guide rollers 4 and 5 of the wire electrode 1 are attached, and these are attached to the main body of the apparatus (not shown). Support members 6 and 7 are attached to the arms 2 and 3 so that their vertical positions can be adjusted by manual handles or motors 8 and 9;
10 is an energizing pin as an upper energizing device that is attached to the support member 6 and applies a voltage to the wire electrode 1 by contacting the wire electrode 1 pressed and displaced by a wear-resistant and usually insulating pressing pin 10';
Reference numeral 11 denotes a current-carrying roller as a lower current-carrying device that also serves as a lower guide roller, and since it is energized by contacting with the wire electrode 1 subjected to wire cut electrical discharge machining, it is a fixed current-carrying pin for the upper clean wire electrode 1. 10 is a rotating roller, and pin 1 is used to increase the contact area.
The diameter is sufficiently large compared to 0, and the energized roller 11
Electricity is supplied from the wire cut electrical discharge machining power source to the roller 11 or the rotating shaft of the roller 11 by brush electricity. 12,1
Reference numeral 3 designates hollow cylindrical nozzle bodies that are attached to support members 6 and 7 in a finely adjustable or fixed manner, and these nozzle bodies 12 and 13
Openings 14, 15 and 16, 17 are formed in the upper and lower end surfaces of the
7 is formed approximately at the center axis of the nozzle bodies 12 and 13, and is arranged in such a positional relationship that the wire electrode 1 is inserted substantially vertically, linearly, and coaxially between the guide rollers 4 and 5. ing. Furthermore, guide holders 20 and 21 of the upper and lower positioning guides 18 and 19 are coaxially fixed inside the nozzle bodies 12 and 13, respectively, and the lower end opening 15 of the upper nozzle body 12 and the lower nozzle Main body 1
The upper end opening 17 of 3 has nozzles 22 and 3, respectively.
23 are coaxially fixed so as to face each other, or are fitted so as to be movable in the axial direction as shown in the illustrated example. The guide holders 20 and 21 have holes 20a and 21a through which the processing fluid flows within the nozzle bodies 12 and 13.
It is a hollow cylindrical body having a cylindrical body, and dice-shaped positioning guides 18 and 19 are attached to the tip. The processed portion 27 of the wire electrode 1 is being positioned. Further, the nozzles 22 and 23 in this example are hollow cylindrical bodies having a desired axial length, inner diameter, and axial inner diameter restriction, and the outer diameters of the flange portions 22a and 23a within the nozzle bodies 12 and 13 are the same as those of the nozzle bodies. The flanges 22a, 23a prevent the nozzle bodies from falling off from the nozzle bodies 12, 13.

Machining fluid machining supply hoses 25 and 26 are attached to the nozzle bodies 12 and 13, respectively, from which machining fluid is supplied into the nozzle bodies 12 and 13 at a predetermined pressure and flow rate, and the internal positioning guide 1
8, 19 are cooled and ejected from the upper and lower nozzles 22, 23 to the processing portion 27 of the workpiece 24 from above and below, respectively, and each nozzle body 12, 13
The machining fluid is jetted out from the openings 14 and 16 at the upper and lower ends and is also supplied between the energizing pin 10 and the energizing roller 11 and the wire electrode 1 to cool the wire electrode 1, the energizing pin 10, and the energizing roller 11. It's becoming like that. Note that the cooling for the energizing roller 11 is as follows:
If the machining liquid is sufficiently flown down from the nozzles 22 and 23 to the machining section 27,
The lower end opening 16 of the nozzle body 13 is connected to the wire electrode 1
be small enough to be inserted through it, or
Or it may be further sealed. That is, as will be described later, in the case of the configuration of the illustrated embodiment,
Since the supply pressure of the machining fluid at the lower nozzle 23, that is, the lower nozzle body 13 side, is set higher than that at the upper part, and it is necessary to maintain this pressure, the opening 16 is made sufficiently small or sealed. be. Therefore, the pressure of the machining fluid supplied from the pressurized supply hose 26 connected to the lower nozzle body 13
P ₁ is higher than the pressure P ₂ of the machining fluid supplied from the pressurized supply hose 25 connected to the upper nozzle body 12 (for example, P ₁ = 5 to 20 Kg/cm ² , P ₂ = 1 to 10 Kg/cm 2 ).
cm ² ), and therefore, if the opening diameters of the nozzles 22 and 23 are approximately the same, the jet amount and flow velocity of the machining fluid will also be larger at the bottom, so that the jet of machining fluid from below will rise against gravity. It's summery. In this illustrated embodiment, the nozzles 22 and 23 are both connected to the nozzle body 12.
and 13, the upper nozzle 22 is movable in the axial direction of the wire electrode 1, and the upper nozzle 22 presses the tip of the nozzle 22 against the surface of the workpiece 24 against a spring 22A provided as necessary, or maintains a minute gap G. The machining fluid is supplied into the nozzle body 12 at a predetermined pressure or the like to cause the nozzle 22 to protrude like a piston, while the lower nozzle 23 is supplied into the nozzle body 13 to maintain the injection pressure of the machining fluid jetted out from the nozzle 23. etc., the tip of the nozzle 23 is connected to the workpiece 24.
Nozzle 2 is placed in a state where it is in complete pressure contact with the lower surface of nozzle 2.
3. Spray the machining fluid onto the tip of the nozzle 23 and the workpiece 2.
This is done so as to prevent leakage and spouting from the contact portion with the lower surface of the fluid to the surroundings as much as possible, or to prevent air from being sucked into the jetted machining fluid from the contact portion. Therefore, the nozzles 22 and 23 are usually made of synthetic resin or are coated with synthetic resin so that the relative movement for processing feed is not inhibited by pressure contact of the nozzle 23 or the nozzle 22 with the workpiece 24. More preferably, electrically insulating and low-friction synthetic resin or the like is used, and an O-ring made of a flexible elastic body is provided at the injection opening of the nozzle 23 for sealing.

Further, the workpiece 24 is fixed to a processing table 31, and the processing table 31 is moved by motors 32 and 33 on a plane perpendicular to the axis of the wire electrode 1 to a predetermined contour shape etc. under the control of a numerical controller. It is now possible to move freely along the Further, the wire electrode 1 is unwound from a storage reel provided in a column or the like of the apparatus main body (not shown) via a brake roller, etc., extends downward via a guide roller 4 of an upper arm 2, and is guided by a lower arm 3. The material is wound up or collected via the roller 5 and a take-up roller (not shown) onto a take-up reel such as a column body or a collection container. Then, intermittent voltage pulses are applied between the workpiece 24 and the wire electrode 1 to perform electrical discharge machining.

Therefore, in the present invention, in the illustrated embodiment, on the drawing side of the wire electrode 1, the one nozzle is The wire electrode 1 from the lower nozzle 23, which is the other nozzle, has a higher machining fluid injection pressure, etc.
This prevents the coaxial jet of machining fluid along the dotted line 39 from flowing from the machining groove 30 formed in the workpiece 24 to a location away from the machining section 27 and leaking to the outside, thereby providing sufficient water to the machining section 27. A piece, strip, short rod, prism, plate, particle, or powder made of a magnetic material and adsorbed to the workpiece 24 so that the machining fluid flows at a predetermined flow rate and flow rate under pressure. , or a flexible material 35 such as rubber or soft synthetic resin in which a magnet 34 (for example, see FIG. 3) of a mixture of the above and the like is embedded or mixed. A pad 36 in the form of a disc is provided. The pad 36 has a circular shape as shown in FIG.
and insert it into the holes in the tightening band 37 and the flanges 37a at both ends of the tightening band 37 and tighten the nut (not shown).
It is designed to be tightened and fixed to the nozzle 22 by a bolt 38 screwed into the nozzle 22, and a plurality of holes 36b are formed and arranged in the circumferential direction in the vicinity of the nozzle 22 to serve as a machining fluid passage section. .

If such a pad 36 is provided, the pad 3
6 and has flexibility, the workpiece 24
Because it adsorbs to the upper surface and closes the upper surface of the machined groove 30 over the range of the outer diameter of the pad 36, it leaks through the part of the machined groove 30 away from the machined part 27, as shown by the dotted line 39. The machining fluid is blocked by the pad 36 and flows out from the hole 36b as shown by the solid line 40.

That is, in the machining fluid that reaches the upper surface of the workpiece 24 due to the machining fluid jet from the lower nozzle 23 where the machining fluid injection pressure is high, there is naturally a considerable amount of machining fluid that flows out to the machining groove 30 side. A flow of the machining fluid flowing out from the hole 36b is also formed as if being pressed by the hole 36b, so that the machining fluid injection pressure in the vicinity of the machining portion 27 can be increased. By creating this flow of processing fluid,
Since the pressure of the machining fluid in the machining section 27 around the wire electrode 1 can be increased and the flow rate and flow rate can be increased, the temperature of the machining section 27 and the wire electrode 1 can be lowered, and With the wire electrode 1, the average machining current can be increased compared to the conventional method, and machining can be performed at high speed, and there is less risk of accidents such as the generation of bubbles or the wire electrode being cut due to the suction of air.

Figure 4 is a diagram showing the relationship between machining fluid flow rate and wire electrode temperature under certain electrode and workpiece conditions.As can be seen from this figure, as the machining fluid flow rate increases, effective contact with wire electrode 1 is made. If the temperature of the wire electrode is increased, the temperature of the wire electrode can be changed significantly, and it can be understood from this that the temperature of the wire electrode can be lowered by increasing the flow rate of the machining fluid in the machining section 27. In addition, FIG. 5 shows the hydraulic pressure of the machining fluid (the injection pressure is the pressure inside the nozzle body 13, and the machining fluid pressure inside the nozzle body 13 is the pressure inside the main body 12).
It is set to 1.5 to 5 times. ) and the amount of bubbles generated in the machining part.
This shows the case where A and 18A are changed.Increasing the fluid pressure suppresses the generation of bubbles.Therefore, by increasing the pressure of the machining fluid in the machining part as in the present invention, the generation of bubbles can be suppressed. It is understood that it is possible to increase the machining speed by reducing the amount generated and to reduce the possibility of wire electrode breakage.

FIGS. 6 and 7 show other embodiments of the present invention. In this embodiment, a pad 36' does not have a liquid passage part over the entire circumference, but a certain range of the flat plate part is cut away. The nozzle body is divided into an upper half 12a to which the pressurized feed hose 25 is connected and a lower half 12b to which the guide holder 20 and nozzle 22 are attached, and the two are rotatably connected. It is. That is, the lower part of the upper half portion 12a is formed to have a U-shaped cross section, and the connecting member 4 having a ring shape and an L-shaped cross section is attached to the U-shaped portion 42.
3 through the seal member 50, and the connecting member 4
By connecting the lower part of 3 to the L-shaped part 51 formed on the upper part of the lower half part 12b with a screw 52 or the like, the upper half part 12a and the lower half part 12b are mutually rotatably connected. A motor 53 having an output gear 54 is attached to the half part 12a, and an external gear 55 fitted to the coupling member 43 is attached to the output gear 54 of the motor 53.
By engaging the motor 53 and rotating the motor 53 in the forward direction, the lower half 12b rotates with respect to the upper half 12a, whereby the cutout 36 of the pad 36' is rotated.
The direction of b' can be changed. A groove 60 is formed in the collar 22a of the nozzle 22, and the groove 60 is slidably fitted into a key 61 vertically provided on the inner wall of the lower half 12b of the nozzle holder, so that the nozzle 22 can be moved downward. It is prevented from rotating relative to the half portion 12b. Note that the nozzle holder 20 may be provided on the upper half portion 12a side.

In this configuration, by driving the motor 53 by the numerical control device so that the cutting part 36b' is positioned in the direction of the groove of the machined part at the current point, the lower nozzle 23 is connected to the machined part in the machining gap or the vicinity thereof. The jet flowing upward through the groove 30 is directed by arrow 5 in FIG.
6, the lower nozzle 23
The jet stream 58 is pushed into the machining section 27, and the flow rate and pressure of the machining fluid in the machining section 27 can be increased more than in the embodiments described above.

FIGS. 8 and 9 show other embodiments of the present invention. In this embodiment, the structure of the lower nozzle is different from the embodiment shown in FIG. Since 22' is a fixed nozzle that is integrated with the nozzle body 12, by adjusting the position of the nozzle body 12, and therefore the tip of the nozzle 22', using the support member 6, the tip of the nozzle 22' can be placed at a minute distance from the upper surface of the workpiece 24. It is positioned so that it is placed or lightly abutting it. In addition, the lower nozzle 23' of this embodiment
The main nozzle 44 is coaxial with the wire electrode 1 and generates a main jet 58 which normally has the highest machining fluid injection pressure, etc., and the main jet 58 is connected to the upper nozzle 2.
Jet machining liquid by 2', workpiece 2 in machining section 27
4. Shape effect due to machining progressing with the cut surface and the wire electrode 1 of the relevant part becoming arcuate or arch-shaped toward the already machined groove side in the direction of machining progress;
and a sub-nozzle 45 that generates an assist jet 59 around the main jet 58, which prevents it from bending due to gravity because it is an upward flow in the vertical direction, that is, as a coaxial jet wrapped around the main jet 58. Furthermore, in this embodiment, the opening 16 of the lower nozzle body 13' is connected to the cylindrical guide holder 21 of the guide 19 so that the main nozzle 44 can easily jet the machining fluid under high machining fluid jet pressure. ', that is, there is no hole 21a on the outer periphery of the guide holder 21', and a minute amount of machining fluid flows from the inside of the holder 21' to the energizing roller 11 side through the minute gap between the guide 19 of the wire electrode 1 and the die. Outside of leaking into
All of the pressurized machining fluid supplied into the lower nozzle body 13' is injected from the main nozzle 44 to the machining section 27 coaxially with the wire electrode 1. The sub-nozzle 45 has a movable main nozzle 44 similar to the nozzle 23 with respect to the lower nozzle body 13', and has a tip opening that is substantially the same, or one of which is slightly recessed relative to the other depending on the processing purpose. fixed in the state,
Preferably, a plurality of pressurized supply hoses 46 for supplying machining fluid to the inside of the sub-nozzle are connected around the sub-nozzle in the same shape.

In this configuration, the pressure of the machining fluid supplied from the pressurized supply hose 26 from the lower nozzle body 13' into the main nozzle 44 is set to, for example, 10 to 20 Kg/cm ² , and the machining fluid supplied from the pressurized supply hose 46 into the sub nozzle 45. The pressure of the machining fluid supplied from the pressurized supply hose 25 from the upper nozzle main body 12 into the upper nozzle 22' is set to, for example, 3 to 10 kg/cm ^{2 .}
Kg/cm ² is set to perform processing, and the main nozzle 44
By supporting the main jet 58 from the sub-nozzle 45 by the assist jet 59 from the sub-nozzle 45, the main jet 58 is prevented from collapsing (bending), and both the pressure and flow rate of the machining fluid in the machining section 27 are increased, which is better than the embodiment described above. machining speed can be increased.
In this case, the lower nozzle 23' protrudes from the lower nozzle body 13' due to the action of the flange portion 44a provided as necessary on the main nozzle 44, and the tips of the main nozzle 44 and the sub nozzle 45 are attached to the workpiece 24. The machining fluid is injected by pressing it against the lower surface, and the state of proximity or contact between the tip of each nozzle and the lower surface of the workpiece 24 is determined by the main nozzle 4, for example.
If you increase the fluid pressure in step 4, the nozzle tip and the bottom surface of the workpiece will come into close contact at a certain fluid pressure value, and if you further increase the fluid pressure, the nozzle tip and the workpiece will come into close contact at a certain fluid pressure value. Machining that changes the relationship between the machining fluid injection pressure settings of the nozzles 22', 44, and 45, the plate thickness of the workpiece 24, and the machining groove, such as a minute gap being formed between the workpiece and the lower surface of the workpiece. conditions, and the machining contour shape (nozzles 22', 44,
45 and the total area of the machined grooves facing the opening surface of 45), the structure and arrangement of the above-mentioned embodiments may vary from a slightly separated state to a slightly strongly pressurized state. Then, each nozzle 2
By setting the high and low values of machining fluid injection pressure, etc. at 2', 44, and 45 in the above-mentioned relationship, the machining average current is increased and the wire electrode 1
High-speed machining can be continued stably without disconnection accidents. As shown in FIG. 10, the direction in which the pressurized supply hose 46 connected to the sub-nozzle 45 injects the machining liquid into the nozzle 45 is directed away from the center of the sub-nozzle 45 to generate a circulating flow. The jet stream 59 is ejected evenly, and uneven pressure is prevented.

In all of the above embodiments, an example was described in which the nozzle is vertically opposed to the machining fluid injection nozzle, but the present invention can also be applied to a case where both nozzles are arranged horizontally to face each other. This is obvious as mentioned above. In addition, the structure of the pad provided on the side of the machining fluid injection nozzle on the side where the machining fluid injection pressure is low is not made of a single member as in the embodiment, but is made of an upper support member such as a rubber plate, etc. It goes without saying that the lower member may be configured to support the lower member, and the structure thereof may also be changed. Further, as another modification, the pad may be attached to the other nozzle side at the same time for processing.

As described above, the feature of the present invention is that the pair of machining fluid injection nozzles are controlled so that their machining fluid injection pressure, flow rate, flow rate, etc. (hereinafter referred to as "machining fluid injection pressure, etc.") are mutually controlled. In the case where the machining fluid injection pressure, etc. is set to be lower than that of the other machining fluid injection nozzle, the machining fluid is attracted to the workpiece made of a magnetic material, and The machining fluid injection pressure, etc. has risen from the other machining fluid jet nozzle, which is set higher than that of the one machining fluid jet nozzle, to the upper surface of the workpiece through the machining part machining gap and the machined machining groove. A pad made of a flexible material with embedded magnets that prevents the machining fluid jet from leaking from the groove machined in the workpiece and allows it to flow out from the vicinity of one of the machining fluid injection nozzles is provided.
Since the machining fluid flow rate, pressure, etc. in the machining section are increased and the generation of bubbles is suppressed, it is possible to increase the machining speed of wire cut electric discharge machining, and it is also possible to prevent wire cutting accidents from occurring.

In addition, the machining fluid injection nozzle on the side with higher pressure, etc.
It is composed of a main nozzle that is coaxial with the wire electrode, and a sub-nozzle that is further coaxially enveloped by the main nozzle to form an annular machining fluid injection port. By being supported, the main jet is prevented from collapsing, and the pressure and flow rate of the machining fluid in the machining section are both increased, making it possible to further increase the machining speed.

Further, the magnetic pad has a notch in a part, and the magnetic pad is arranged around the axis of the wire electrode on the side of the one machining fluid injection nozzle so that the notch is on the tip side in the machining feed direction. Since the notch is mounted so that it can be rotated in a controlled manner, by performing machining with the notch facing forward in the machining direction, the jet flow is directed from the machining fluid injection nozzle on the side where the pressure is high to the machining fluid injection nozzle on the side where the pressure is low. The machining fluid jet can be directed forward in the machining direction, and the machining fluid jet is forced into the machining section, increasing both the pressure and flow rate in the machining section, thereby further increasing the machining speed.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view showing one embodiment of the nozzle device of the present invention, FIG. 2 is a perspective view of the upper nozzle part of FIG. 1, FIG. 3 is a sectional view of the pad of FIG. 1, and FIG. 4 5 is a diagram showing the relationship between the flow rate of the machining fluid and the electrode temperature, FIG. 5 is a diagram showing the relationship between the fluid pressure of the machining fluid and the amount of bubbles generated, and FIG. 6 is a partial cutaway of the upper nozzle showing another embodiment of the present invention. FIG. 7 is a sectional view of the nozzle work explaining its operation; FIG. 8 is a vertical sectional view showing another embodiment of the present invention; FIG. 9 is a plan view of the nozzle below the nozzle;
The figure is a modification of FIG. 9. 1...Wire electrode, 22...Upper nozzle, 23,2
3'... Lower nozzle, 24... Workpiece, 27... Machining section, 30... Machining groove, 36, 36'... Pad, 36
b...hole, 36b'...excision part, 44...main nozzle,
45...Sub nozzle.

Claims (1)

[Scope of Claims] 1. While a wire electrode is updated and moved in the axial direction between a pair of positioning guides arranged at intervals, a workpiece is moved relative to the workpiece from a direction perpendicular to the axial direction of the wire electrode through a minute gap. The machining fluid is injected into the gap from a pair of machining fluid injection nozzles disposed coaxially with and opposite to the wire electrode on both sides of the workpiece. In wire cut electric discharge machining, machining is performed by electric discharge generated by applying a voltage pulse, and a relative machining feed is provided between the wire electrode and the workpiece on the plane in the orthogonal direction, the pair of machining fluids are sprayed. The nozzles are configured with different machining fluid injection pressures, flow velocities, flow rates, etc. (hereinafter referred to as "machining fluid injection pressures, etc."), and the machining fluid injection pressures, etc. are lower than those of the other nozzles. A flexible material having a plate shape that is sufficiently larger than the outer diameter of the one machining fluid jet nozzle and embedded with a magnet that attracts the workpiece around the tip of one of the machining fluid jet nozzles on the set side. A nozzle device for wire cut electric discharge machining, characterized in that a magnetic pad having a hole for passing machining fluid is provided near the tip of one of the nozzles. 2. Wire cut electrical discharge machining in which the axis of the wire electrode in the machining section between the pair of positioning guides is substantially aligned with a vertical line, and one of the machining fluid injection nozzles is provided on the upper side of the workpiece. A nozzle device for wire cut electric discharge machining according to claim 1, characterized in that: 3. One or both of the one and the other machining fluid injection nozzles comprises a nozzle that moves forward and backward in the wire electrode axial direction in accordance with the supply and jetting of the machining fluid. The wire cut electric discharge machining nozzle device according to any one of Item 2. 4. While the wire electrode is renewedly moved in the axial direction between a pair of positioning guides arranged at intervals, the workpiece is faced to each other through a minute gap from a direction perpendicular to the axial direction of the wire electrode, and the workpiece is placed in the gap. The process is generated by applying intermittent voltage pulses between the wire electrode and the workpiece while injecting and supplying the machining liquid from a pair of machining liquid injection nozzles arranged coaxially with the wire electrode and facing each other on both sides of the workpiece. In wire cut electrical discharge machining, which performs machining by electric discharge and provides relative machining feed between the wire electrode and the workpiece on the plane in the perpendicular direction, the pair of machining fluid injection nozzles spray the machining fluid. The machining fluid injection nozzles are configured to have different pressures, etc., and are arranged around the tip of one of the machining fluid jet nozzles on the side where the machining fluid jetting pressure, etc. is set lower than the other machining fluid jetting nozzle. It is made of a flexible material having a plate shape sufficiently larger than the outer diameter and embedded with a magnet that attracts the workpiece, and has a hole or notch for passing the machining fluid near or around the tip of one of the nozzles. The other machining liquid injection nozzle is composed of a main nozzle coaxial with the wire electrode, and a sub-nozzle further coaxially surrounding the main nozzle to form an annular machining liquid injection port. A nozzle device for wire cut electric discharge machining characterized by the following. 5 While the wire electrode is renewedly moved in the axial direction between a pair of positioning guides arranged at intervals, the workpiece is made to face each other through a minute gap from a direction perpendicular to the axial direction of the wire electrode, and the workpiece is placed in the gap. Generated by applying intermittent voltage pulses between the wire electrode and the workpiece while injecting and supplying machining fluid from a pair of machining fluid injection nozzles disposed coaxially with the wire electrode and facing each other on both sides of the workpiece. In wire cut electrical discharge machining, which performs machining by electric discharge and provides a relative machining feed between the wire electrode and the workpiece on the plane in the perpendicular direction, the pair of machining fluid injection nozzles spray the machining fluid. The machining fluid injection nozzles are configured to have different pressures, etc., and are arranged around the tip of one of the machining fluid injection nozzles on the side where the machining fluid injection pressure, etc. is set lower than that of the other machining fluid injection nozzle. A magnetic pad made of a flexible material is provided, which has a plate shape sufficiently larger than the outer diameter and has a magnet embedded therein that attracts it to the workpiece, and the magnetic pad has a notch in a part. A wire cut for electric discharge machining, characterized in that the part is mounted on the side of the one machining fluid spray nozzle so as to be controllably rotatable around the axis of the wire electrode so that the part is on the tip side in the machining feed direction. nozzle device.