JP5335164B1 - Wire electrical discharge machine - Google Patents

Abstract

  In order to prevent the occurrence of fire at the time of wire cutting with a compact configuration, the wire electric discharge machining apparatus is located at a position facing the fusing electrode (32) for fusing the wire (1) via the wire (1). A wire pressing pad (33) for holding the wire (1) in cooperation with the fusing electrode (32) when the wire (1) is fusing, and the cover (37) has a fusing electrode ( 32) and the wire pressing pad (33) are housed, and a current is passed through the wire (1) to melt the wire (1).

Description

  The present invention relates to a wire electric discharge machining apparatus having a function of automatically cutting a wire electrode.

  Some wire electric discharge machining apparatuses equipped with an automatic control device are provided with an automatic wire connection function (hereinafter referred to as a wire) or an automatic repair connection function in preparation for unattended operation for a long time. The automatic wire connection function is a function of the control device provided in the wire electric discharge machining apparatus when the machining of one figure on the workpiece (hereinafter referred to as a workpiece) is completed and the machining of the next figure is set. This is a function that once cuts a wire in a connected state according to a command, moves the wire to a new processing start hole position on the workpiece, and inserts a new wire into the processing start hole to establish a connection state. . In addition, the automatic repair connection function allows the tip of the wire left on the upstream side of the wire traveling direction in response to a command from the control device that detects when the wire is disconnected for some reason during the processing of a single figure. This is a function of repairing the connection state by cutting the wire and passing the tip again through the hole (or groove) of the workpiece being processed.

  Generally, wire electric discharge machines that use oil as the machining fluid have a risk of fire, so a mechanical cutting structure with a blade is used to cut the wire. This occurs and there is a problem that the connection performance deteriorates. On the other hand, when wire fusing by heat is adopted, the wire tip after cutting is sharp and sharp, and the connection performance is improved. However, when sparks are scattered, there is a risk of fire.

As a technique related to the automatic wire connection function, Patent Document 1 discloses a technique of performing wire fusing by heat generated by applying a high-frequency current to a solenoid coil.
As a technique related to a technique for preventing a fire, for example, Patent Document 2 discloses a technique for extinguishing a fire by injecting a non-combustible gas into a processing tank when the detector detects a fire in the processing tank. ing.

JP 61-008225 A JP 59-232743 A

  However, according to the technique of the above-mentioned patent document 2, it is necessary to provide a mechanism for sealing incombustible gas in the processing tank or to provide various sensors. This causes a problem that the structure of the entire apparatus becomes large.

  This invention is made | formed in view of the above, Comprising: It aims at obtaining the wire electric discharge machining apparatus which can prevent generation | occurrence | production of the fire at the time of wire cutting with a compact structure.

In order to solve the above-described problems and achieve the object, the wire electric discharge machining apparatus of the present invention includes a fusing electrode for fusing the wire electrode and a movable first cover, and at the time of cutting the wire electrode, The fusing electrode and a fusing part due to the fusing electrode are covered with a first cover, and the first cover is moved from the fusing part when the wire electrode is connected .

  The wire electric discharge machining apparatus according to the present invention can prevent the occurrence of a fire without requiring a sensor by covering only the melted part with a cover, and thus can prevent the occurrence of a fire with a compact configuration.

FIG. 1 is a diagram illustrating a configuration of a wire electric discharge machining apparatus according to an embodiment. FIG. 2-1 is a diagram illustrating a configuration of a cutting energization unit. FIG. 2-2 is a cross-sectional view illustrating a configuration of the cutting energization unit. FIG. 3 is a diagram for explaining the operation of the automatic wire feeder in automatic connection. FIG. 4 is a diagram for explaining the operation during automatic cutting of the automatic wire feeder.

  Embodiments of a wire electric discharge machining apparatus according to the present invention will be described below in detail with reference to the drawings. Note that the present invention is not limited to the embodiments.

Embodiment.
FIG. 1 is a diagram showing a configuration of a wire electric discharge machining apparatus according to an embodiment of the present invention. As shown in the figure, the wire electric discharge machining apparatus 100 includes a wire bobbin 3, pulleys 4 to 7, a capstan roller 8, a pinch roller 9, a pinch roller 10, a tension control device 11, a roller 13, a lower wire guide 14, a winding roller 15, A winding motor 16 and an automatic wire feeding device 300 are provided. The wire electric discharge machining apparatus 100 can machine the workpiece 2 by causing an electric discharge between the wire 1 and the workpiece 2. The wire electrical discharge machining apparatus 100 performs electrical discharge machining in a state where the workpiece 2 is immersed in a machining tank (not shown) filled with a machining fluid.

  The wire bobbin 3 supplies the wire 1. The pulleys 4 to 7 change the traveling direction of the wire 1 so that the wire 1 travels on a predetermined route.

  The capstan roller 8, the pinch roller 9, the pinch roller 10, and the tension control device 11 constitute a tension control unit 200. The capstan roller 8 holds the wire 1 whose direction is changed by the pulley 7 in cooperation with the pinch rollers 9 and 10. The capstan roller 8 is driven by a tension control device 11 that is a motor, and applies a predetermined tension to the wire 1 with the winding roller 15 during processing.

  The automatic wire feeder 300 includes a guide pipe 12 that restrains the path of the wire 1. The wire 1 that has passed through the capstan roller 8 passes through the guide pipe 12. The roller 13 changes the traveling direction of the wire 1 that has passed through the guide pipe 12 and introduces the wire 1 into the lower wire guide 14. At the outlet of the lower wire guide 14, the wire 1 is held between a pair of winding rollers 15. The winding roller 15 is driven by a winding motor 16 and can run the wire 1 at a predetermined speed during processing.

  In the wire electric discharge machining apparatus 100 configured as described above, the wire 1 is fed out from the wire bobbin 3, changed in direction by the pulleys 4 to 7, and passes through the tension control unit 200 and the automatic wire feeding apparatus 300. Then, after performing electric discharge machining on the workpiece 2, it passes through the roller 13 and the lower wire guide 14, is wound up by the winding roller 15, and is collected in a collection box (not shown).

  In addition to the guide pipe 12, the automatic wire supply device 300 includes a drive mechanism (for example, an air cylinder, a hydraulic cylinder, and a motor) 17 that moves the guide pipe 12 up and down by air pressure. Here, the automatic wire feeder 300 has a function of automatic cutting that automatically cuts the wire 1 when the wire is disconnected and at the end of processing, in addition to the function of automatic connection. As a configuration for realizing the automatic cutting function, the automatic wire feeding device 300 includes a cutting energization unit 23, a cutting capstan roller 24, and a cutting pinch roller 25. When the wire automatic cutting device 300 cuts the wire 1, the wire 1 is held between the cutting capstan roller 24 and the cutting pinch roller 25, and the capstan roller 8 is connected to the wire 1 by the holding. Give tension between. Then, the automatic wire feeding device 300 blows the wire 1 in the vicinity of the cutting energization unit 23 by flowing a current through a pair of fusing electrodes (the fusing electrode 32-1 and the fusing electrode 32-2) included in the cutting energization unit 23. To do. The automatic wire connection device 300 is covered with an automatic wire connection device cover 39.

  FIG. 2A is a cross-sectional view illustrating a configuration of the cutting energization unit 23. As shown in the drawing, the cutting energization section 23 includes a flame retardant electrode cover 30, a flame retardant pad cover 31, a fusing electrode 32-1, a fusing electrode 32-2, a wire pressing pad 33-1, and a wire pressing pad 33. -2. The wire pressing pad 33-1 and the wire pressing pad 33-2 are disposed so as to face the fusing electrode 32-1 and the fusing electrode 32-2 with the wire 1 interposed therebetween. The electrode cover 30 is disposed so as to cover one side of the fusing electrode 32-1 and the fusing electrode 32-2 and the side opposite to the wire 1. The pad cover 31 is disposed so as to cover one side of the wire pressing pad 33-1 and the wire pressing pad 33-2 and the opposite side to the wire 1. Hereinafter, the fusing electrode 32-1 and the fusing electrode 32-2 may be collectively referred to as a fusing electrode 32. Further, the wire pressing pad 33-1 and the wire pressing pad 33-2 may be collectively referred to as a wire pressing pad 33.

  FIG. 2-2 is a cross-sectional view illustrating a state of the cutting energization unit 23 during automatic cutting. The wire pressing pad 33 and the fusing electrode 32 are configured to be movable. The wire pressing pad 33 and the fusing electrode 32 are moved so as to be in a state of sandwiching the wire 1 (a state of pinching) in cooperation with each other during automatic cutting. When the fusing electrode 32 is moved, the fusing electrode 32 and the electrode cover 30 are moved together. Further, the wire pressing pad 33 and the pad cover 31 are moved together. During automatic cutting, the electrode cover 30 and the pad cover 31 cover the fusing electrode 32, and one or both of the electrode cover 30 and the pad cover 31 have one or more fluid inlets 35 and outlets 36. Yes. At this time, the fluid 38 is 0.3 to 0.5 MPa.

  FIG. 3 is a diagram for explaining the operation of the automatic wire feeder 300 during automatic connection. During automatic connection, the automatic wire supply device 300 moves the fusing electrode 32 and the wire pressing pad 33 in a direction perpendicular to the traveling direction of the wire 1 and away from each other. Thereby, the fusing electrode 32 and the wire pressing pad 33 are in a state in which the wire 1 is not sandwiched, and the electrode cover 30 and the pad cover 31 are in a state of being separated from each other (that is, the same state as the state of FIG. 2-1). To do). In this state, the automatic wire feeder 300 lowers the guide pipe 12 and passes between the fusing electrode 32 and the wire pressing pad 33. At that time, the automatic wire supply device 300 conveys the wire 1 downward by flowing the carrier fluid 34 into the guide pipe 12.

  FIG. 4 is a diagram for explaining the operation of the automatic wire feeder 300 during automatic cutting. During automatic cutting, the automatic wire feeder 300 raises the guide pipe 12 from the state shown in FIG. Then, the automatic wire feeding device 300 closes the fusing electrode 32 and the wire pressing pad 33 so as to sandwich the wire 1 between the fusing electrode 32 and the wire pressing pad 33 (that is, the same state as the state of FIG. 2-2). And). In a state where the fusing electrode 32 and the wire pressing pad 33 are closed, the electrode cover 30 and the pad cover 31 constitute a cover 37 that accommodates the fusing electrode 32 and the wire pressing pad 33. Here, a description will be given of a structure in which an inflow port 35 is provided in the upper portion of the cover 37 and an outflow port 36 is provided in the lower portion, and the carrier fluid 34 that flows in the guide pipe 12 is used as the fluid 38. The cover 37 can cover the fusing electrode 32 and the wire pressing pad 33 except for the portion of the inlet 35 provided in the upper portion and the outlet 36 provided in the lower portion.

  Further, the automatic wire feeding device 300 stops the raising of the guide pipe 12 at a position where the tip of the guide pipe 12 is inserted into the inflow port 35. The gap between the inlet 35 and the guide pipe 12 and the gap between the outlet 36 and the wire 1 are sufficiently narrow, and the inside of the cover 37 formed by the electrode cover 30 and the pad cover 31 is a carrier fluid 34 flowing from the guide pipe 12. The inside of the cover 37 is at a pressure higher than atmospheric pressure. At this time, the wire automatic supply device 300 supplies a current between the fusing electrode 32-1 and the fusing electrode 32-2 in a state where oil inside the cover 37 or oil attached to the wire 1 is discharged from the cover 37. By flowing, it is possible to prevent the occurrence of fire during automatic cutting.

  Note that a flame-retardant liquid including a machining liquid can be used as the carrier fluid 34. When a flame-retardant liquid is adopted as the carrier fluid 34, oxygen can be removed from the cover 37, or heat generated by fusing can be quickly removed. Can be prevented.

  Further, compressed air or incombustible gas (for example, nitrogen, argon, helium) can be adopted as the carrier fluid 34. When air or a non-combustible gas is used as the carrier fluid 34, oil adhering to the wire 1 or oil splashes inside the cover 37 can be removed to the outside of the cover 37. Occurrence can be prevented.

  In addition, the wire automatic supply device 300 may perform the fusing while blowing the carrier fluid 34 to the portion to be melted in the cover 37 instead of the cover 37 being filled with the carrier fluid 34. Even in this case, since the fusing can be executed while removing the oil adhering to the wire 1, it is possible to prevent the occurrence of a fire during automatic cutting.

  Further, the cover 37 is sealed by eliminating the gap between the inlet 35 and the guide pipe 12 and the gap between the outlet 36 and the wire 1, and the automatic wire feeder 300 does not flow the carrier fluid 34 during automatic cutting. You can do it. Thereby, even if ignition occurs in the cover 37, oxygen in the cover 37 is deficient and the fire is quickly extinguished, so that it is possible to prevent the occurrence of fire during automatic cutting. Note that the automatic wire feeding device 300 may be lifted so that the tip of the guide pipe 12 is positioned above the cover 37 during automatic cutting, and the gap between the inlet 35 and the wire 1 may be eliminated.

  In addition, at least one or more flame retardant automatic wire connection device cover 39 is provided outside the cover 27 so that the fluid blown from the cover 27 does not scatter.

  As described above, according to the embodiment of the present invention, the wire electric discharge machining apparatus 100 is disposed at a position facing the fusing electrode 32 for fusing the wire 1 via the wire 1. A wire pressing pad 33 for holding the wire 1 in cooperation with the fusing electrode 32 at the time of fusing, and a current is passed through the wire 1 in a state where the fusing electrode 32 and the wire pressing pad 33 are accommodated in the cover 37. Since the wire 1 is melted, the occurrence of a fire can be prevented. Moreover, since the wire electric discharge machining apparatus 100 can prevent the occurrence of fire without requiring a sensor by covering only the fusing part, the wire electric discharge machining apparatus 100 can be made compact. Moreover, since the wire electric discharge machining apparatus 100 cuts the wire 1 by fusing, the cutting portion of the wire 1 can be sharpened, so that the connection performance is improved as compared with the case of cutting the wire 1 with a blade.

  As described above, the wire electric discharge machining apparatus according to the present invention is suitable for application to a wire electric discharge machining apparatus having a function of automatically cutting a wire electrode.

  1 wire, 2 workpieces, 3 wire bobbins, 4, 5, 6, 7 pulley, 8 capstan roller, 9, 10 pinch roller, 11 tension control device, 12 guide pipe, 13 roller, 14 lower wire guide, 15 winding roller, 16 winding motor, 17 drive mechanism, 23 cutting energization part, 24 cutting capstan roller, 25 cutting pinch roller, 30 electrode cover, 31 pad cover, 32, 32-1, 32-2 fusing electrode, 33, 33- DESCRIPTION OF SYMBOLS 1,33-2 Wire pressing pad, 34 Conveyance fluid, 35 Inflow port, 36 Outlet port, 37 Cover, 38 Fluid, 39 Automatic wire connection device cover, 100 Wire electric discharge machining device, 200 Tension control part, 300 Wire automatic supply device.

Claims (12)

A fusing electrode for fusing the wire electrode and a movable first cover are provided. When the wire electrode is cut, the fusing electrode and a fusing part by the fusing electrode are covered with the first cover, and when the wire electrode is connected The wire electric discharge machining apparatus , wherein the first cover is moved from the fusing part . The wire electric discharge machining apparatus according to claim 1 , wherein a fluid is sealed in the first cover when the wire electrode is cut . The wire pressing pad is disposed at a position facing the fusing electrode via the wire electrode, and includes a wire pressing pad for holding the wire electrode in cooperation with the fusing electrode when the wire electrode is cut. Cover
A second cover that covers one side of the fusing electrode and is moved together with the fusing electrode;
A third cover that covers one side of the wire pressing pad and is moved together with the wire pressing pad;
With
The wire electrode is connected by moving the fusing electrode and the wire pressing pad in a direction perpendicular to the traveling direction of the wire electrode and in a direction away from each other. Item 3. A wire electric discharge machining apparatus according to Item 2. The first cover includes a fluid inlet and the fluid outlet,
The wire electric discharge machining apparatus according to claim 2 or 3, wherein the wire electrode is blown while spraying the fluid to a fusing part.   The wire electric discharge machining apparatus according to claim 2, 3 or 4, wherein the fluid is compressed air or non-combustible gas.   The wire electric discharge machining apparatus according to claim 2, wherein the fluid is a machining liquid or a nonflammable liquid.   The wire electric discharge machining apparatus according to claim 5, wherein the fluid is a liquid for conveying a wire electrode. The first cover includes a fluid inlet and the fluid outlet,
The wire electric discharge machining apparatus according to claim 1, wherein the wire electrode is melted while the first cover is filled with the fluid.   The wire electric discharge machining apparatus according to claim 8, wherein the fluid is air or a nonflammable gas.   The wire electric discharge machining apparatus according to claim 8, wherein the fluid is a machining liquid or a nonflammable liquid.   The wire electric discharge machining apparatus according to claim 8, wherein the fluid is a liquid for conveying a wire electrode.   The wire electric discharge machining apparatus according to claim 1, wherein the first cover has a sealed structure.

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