Wire electrical discharge machining device

Abstract

The present invention provides a wire electric discharge machining device capable of mechanically changing the contact state of a current conductor and a wire electrode. According to the present invention, a wire electric discharge machining device including a wire electrode and upper and lower guide devices that guide the wire electrode is provided, the lower guide device including a current conductor that moves in a horizontal single-axis direction, i.e., a first direction, to contact the wire electrode to supply power, and a fixing device that fixes the current conductor in the lower guide device; the fixing device is configured to be able to switch between a fixed state in which the current conductor is not relatively movable with respect to the lower guide device in another horizontal single-axis direction, i.e., a second direction, orthogonal to the first direction, and an unfixed state in which the current conductor is relatively movable with respect to the lower guide device in the second direction; and includes a pressing device that presses the current conductor in the unfixed state to move in the second direction in a manner relatively movable with respect to the lower guide device, and a moving device that relatively moves the pressing device with respect to the lower guide device.

Description

Technical Field

[0001] This invention relates to a wire electrical discharge machining apparatus. Background Technology

[0002] Wire electrical discharge machining (FEDM) refers to a machining method in which intermittent and repeated discharges occur in the machining gap formed between a wire electrode (which serves as a tool electrode) and the workpiece, using the discharge energy to cut the workpiece into the desired shape. Typically, the wire electrode is positioned by a pair of wire conductors that clamp the horizontally positioned workpiece. During machining, the wire conductors guide the wire electrode along a predetermined path at a predetermined feed speed, continuously supplying current to the unused portion of the machining gap. At least one of the upper and lower guide devices, each including wire conductors, houses a current-carrying body electrically connected to one pole of the machining power source, supplying current to the wire electrode through contact with the current-carrying body.

[0003] The conductor may contain a wear-resistant conductive metal material such as tungsten carbide, but it wears out due to prolonged contact with the moving wire electrode, making it unable to supply sufficient current to the wire electrode. Therefore, the conductor is replaced with a new one after a predetermined period of use. However, depending on the shape of the conductor, it is not replaced immediately, but rather the position of contact between the conductor and the wire electrode can be changed to extend its service life as much as possible. In the wire conductor device disclosed in Patent Document 1, the contact state between the conductor and the wire electrode can be changed by manually moving the conductor within an internal support hole.

[0004] [Existing Technical Documents]

[0005] [Patent Literature]

[0006] [Patent Document 1] Japanese Utility Model Registration No. 2521251 Summary of the Invention

[0007] [The problem the invention aims to solve]

[0008] As disclosed in Patent Document 1, the wire guide device performs the following operation: When changing the position of the energized body in contact with the wire electrode, the operator uses a special tool to loosen the nut, releasing the energized body from its fixed state. The energized body then slides a predetermined amount in a horizontal single-axis direction orthogonal to the wire electrode erected in the vertical direction before being fixed again. At this time, peripheral components such as machining groove walls, machining heads, automatic wiring devices, and workstations exist around the guide device, becoming obstacles to the operation. Especially when changing the position of the energized body located in the lower guide device below the workpiece, it is difficult for the operator to reach the lower guide device, and it is also difficult to operate the tool, increasing the operator's burden. Therefore, it is desirable to reduce the operator's burden and shorten the operation time in the operation of changing the position by sliding the energized body.

[0009] The present invention was made in view of the above-described circumstances, and its object is to provide a wire discharge machining apparatus capable of mechanically changing the contact state between a current-carrying body and a wire electrode.

[0010] [Technical means to solve the problem]

[0011] According to the present invention, a wire electrical discharge machining (EDM) apparatus is provided, comprising a wire electrode, an upper guide device, and a lower guide device, wherein the upper guide device and the lower guide device are respectively disposed on the upper and lower sides of the workpiece to guide the wire electrode by clamping the workpiece along the vertical direction; the lower guide device includes: a current-carrying body and a fixing device for fixing the current-carrying body at a predetermined position within the lower guide device; the current-carrying body provides power by moving in a horizontal uniaxial direction, i.e., a first direction, and contacting the wire electrode; the fixing device is configured as follows: The device is capable of switching between the following states: a fixed state, in which the energized body cannot move relative to the lower guide device in a second direction orthogonal to the first direction; and a non-fixed state, in which the energized body can move relative to the lower guide device in the second direction; and includes: a pressing device configured to move relative to the lower guide device to press the energized body in the non-fixed state to move it in the second direction; and a moving device to move the pressing device relative to the lower guide device.

[0012] [The effects of the invention]

[0013] According to the wire electrical discharge machining apparatus of the present invention, at least in the lower guide device, a fixing device that fixes the lower energizer to a predetermined position within the lower guide device by reciprocating it in a first direction (the direction in which the lower energizer contacts and separates from the wire electrode), thereby switching between a fixed state where the lower energizer cannot move relative to the lower guide device and a non-fixed state where it can move relative to the lower guide device. Furthermore, a pressing device presses the non-fixed lower energizer, causing it to move in a second direction (another horizontal uniaxial direction orthogonal to the first direction). Therefore, the lower energizer can be moved mechanically to change its contact position with the wire electrode without relying on manual operation by the operator. This reduces the operator's workload and shortens the operation time during the change of the lower energizer's position.

[0014] The following examples illustrate various embodiments of the present invention. These embodiments can be combined with each other.

[0015] Preferably, the fixing device is configured to reciprocate the energized body in the first direction.

[0016] Preferably, the moving and fixing device for the energized body includes a piston power cylinder and a force-applying component. The force-applying component is configured to apply force to the lower energized body in the first direction. In the fixed state, the piston power cylinder resists the force applied by the force-applying component and squeezes the lower energized body out in the first direction toward the direction close to the wire electrode to fix it. In the non-fixed state, the force-applying component squeezes the lower energized body out in the first direction toward the direction away from the wire electrode.

[0017] Preferably, the lower guide device includes a guide block that houses the energized body in a storage space formed therein, and in the fixed state, the power cylinder pushes the energized body out, causing it to abut against the wall of the storage space and be fixed thereto.

[0018] Preferably, the extrusion device includes: a body portion connected to the moving device; and an extrusion pin continuously disposed from the body portion, protruding from the body portion in one of the second directions such that its front end can abut against the energized body in the lower guide device.

[0019] Preferably, the extrusion pin is configured to be movable to a retracted position during the electrical discharge machining of the workpiece, without interfering with the lower guide device.

[0020] Preferably, the extrusion device uses the extrusion pin as the first extrusion pin and the main body portion as the first main body portion; it also includes: a second main body portion connected to the moving device; and a second extrusion pin continuously disposed from the second main body portion and protruding from the second main body portion in another direction in the second direction such that its front end can abut against the energized body in the lower guide device; and the first extrusion pin and the second extrusion pin are configured to clamp the energized body in the second direction.

[0021] Preferably, the upper guide device includes a power-conducting body and a fixing device; the power-conducting body supplies power by moving in a horizontal single-axis direction, i.e., a third direction, to contact the wire electrode; the fixing device is configured to switch between the following states: a fixed state, in which the power-conducting body cannot move relative to the upper guide device in another horizontal single-axis direction orthogonal to the third direction, i.e., a fourth direction; and a non-fixed state, in which the power-conducting body can move relative to the upper guide device in the fourth direction; and is configured to be able to move relative to the upper guide device; and the wire electrical discharge machining apparatus includes: a pressing device for pressing the non-fixed power-conducting body to move in the fourth direction; and a moving device for moving the pressing device relative to the upper guide device. Attached Figure Description

[0022] Figure 1 This is a schematic diagram illustrating a wire electrical discharge machining apparatus 100 according to an embodiment of the present invention.

[0023] Figure 2 This is a perspective view taken from above the lower guide device 31b.

[0024] Figure 3 This is a perspective view from above the lower guide device 31b.

[0025] Figure 4 This is an exploded perspective view taken from above the housing 4 of the lower guide device 31b.

[0026] Figure 5 This is an exploded perspective view from below the housing 4 of the lower guide device 31b.

[0027] Figure 6 This is under the condition that the lower energized body 33b is in a fixed state. Figure 2 AA section view.

[0028] Figure 7 This is under the condition that the lower energized body 33b is in a fixed state. Figure 2 BB cross-section diagram.

[0029] Figure 8 This is when the lower energized body 33b is in a non-fixed state. Figure 2 BB cross-section diagram.

[0030] Figure 9 This is a schematic diagram showing the structure of the extrusion device 8.

[0031] Figure 10 This is a schematic diagram showing the state of the first compression pin 82 in the retracted position.

[0032] Figure 11 This is a block diagram representing the structure of control device 7.

[0033] Figure 12 This is a schematic diagram showing the structure of the extrusion device 8 in another embodiment.

[0034] [Explanation of Symbols]

[0035] 1: Line supply organization

[0036] 2: Wire electrode

[0037] 3: Wire conductor mechanism

[0038] 4: Casing

[0039] 6: Line recycling mechanism

[0040] 7: Control device

[0041] 8: Extrusion device

[0042] 10: Machining clearance

[0043] 11: Reel

[0044] 12: Thread reel

[0045] 13: Braking device

[0046] 14: Servo pulley

[0047] 15: Tension Imparting Device

[0048] 15a: Feed roller

[0049] 15b: Conveyor motor

[0050] 15c: Tension detector

[0051] 15d: Pressure roller

[0052] 16: Wire breakage detector

[0053] 17: Automatic wiring device

[0054] 18: Catheter

[0055] 19: Lifting device

[0056] 20: Linear Vibration Device

[0057] 21: Base

[0058] 22: Platform

[0059] 23: Workstation

[0060] 31a: Upper guide device

[0061] 31b: Lower guide device

[0062] 32a: Upper side wire guide

[0063] 32b: Lower side wire guide

[0064] 32b1: Guide hole

[0065] 33a: Upper energized body

[0066] 33b: Lower side energized body

[0067] 33b1: End face

[0068] 33b2: End face

[0069] 41: Base

[0070] 41a: Electrode insertion hole

[0071] 41b: concave part

[0072] 42: Guide block

[0073] 42a: Electrode insertion hole

[0074] 42b: Through hole

[0075] 42d: Storage space

[0076] 42d1: Opening

[0077] 42d2: Opening

[0078] 42e: Protrusion

[0079] 42f: wall

[0080] 43: Slider

[0081] 43a: Flat plate section

[0082] 43a1: Electrode insertion hole

[0083] 43a2: Through hole

[0084] 43b: Shaft

[0085] 43c: Cylindrical section

[0086] 43c1: Opening

[0087] 43c2: Insertion hole

[0088] 44: Jet Nozzle

[0089] 44a: Electrode insertion hole

[0090] 51: Export guide

[0091] 52: Force-applying components

[0092] 53: Covering component

[0093] 54: Piston Bolt

[0094] 54a: Ball

[0095] 54b: Spring

[0096] 55: Power Cylinder

[0097] 55a: Cylinder

[0098] 55b: Piston

[0099] 56: Connecting pipe

[0100] 57: Scraper

[0101] 58: Tablet

[0102] 61: Steering roller

[0103] 62: Transport tube

[0104] 63: Suction machine

[0105] 64: Winding device

[0106] 64a: Winding roller

[0107] 64b: Pressure roller

[0108] 64c: Winding motor

[0109] 65: Wire cutting machine

[0110] 66: Bucket

[0111] 71: Input device

[0112] 72: Numerical control device

[0113] 73: Mobility control device

[0114] 81: Ontology Department

[0115] 82: First extrusion pin

[0116] 83: Ontology Department

[0117] 84: Second extrusion pin

[0118] 91: Power supply unit

[0119] 92: Compressed air supply device

[0120] 93: Processing fluid supply device

[0121] 100: Wire EDM apparatus

[0122] W: Workpiece Detailed Implementation

[0123] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. The features shown in the embodiments described below can be combined with each other. Furthermore, each feature constitutes an invention independently.

[0124] 1. Wire EDM apparatus

[0125] 1.1. Overall Structure

[0126] Figure 1 This is a schematic diagram illustrating a wire electrical discharge machining apparatus 100 according to an embodiment of the present invention. (As shown) Figure 1 As shown, the wire electrical discharge machining apparatus 100 of this embodiment includes a wire electrode 2, an upper guide device 31a, and a lower guide device 31b. The upper guide device 31a and the lower guide device 31b are respectively disposed on the upper and lower sides in a manner that clamps the workpiece W in the vertical direction to guide the wire electrode 2. The wire electrode 2 is inserted through a lower hole formed in the workpiece W, and machining is performed by discharging through the machining gap 10 formed between the wire electrode 2 and the workpiece W.

[0127] The wire electrical discharge machining (EDM) apparatus 100 includes, in sequence along the travel path of the wire electrode 2: a wire supply mechanism 1, an automatic wiring device 17, a wire guide mechanism 3, and a wire retrieval mechanism 6. Furthermore, the wire EDM apparatus 100 includes a power supply device 91, a compressed air supply device 92, and a machining fluid supply device 93. In the following description, along the travel path of the wire electrode 2, the side closer to the wire supply mechanism 1 is designated as upstream, and the side closer to the wire retrieval mechanism 6 is designated as downstream. Moreover, regarding the rotation direction of the plurality of rotating bodies, such as guide rollers, located along the travel path of the wire electrode 2 in the wire EDM apparatus 100, the direction of rotation when the wire electrode 2 travels from upstream to downstream is designated as the forward rotation direction, and the rotation direction opposite to the forward rotation direction is designated as the reverse rotation direction.

[0128] 1.2. Line Supply Organization 1

[0129] The wire supply mechanism 1 is configured to continuously supply new wire electrodes 2 along a predetermined travel path, and mainly includes: a reel 11, a braking device 13, a servo pulley 14, a tension applying device 15, and a wire breakage detector 16. When the spool 12 mounted on the reel 11 rotates in the forward direction, new wire electrodes 2 are continuously drawn out. The braking device 13, for example, is a brake motor such as a hysteresis motor or an electromagnetic brake such as an electromagnetic clutch, applies a torque in the reverse direction to the reel 11 to prevent the spool 12 from spinning freely and to prevent the wire electrodes 2 from slackening.

[0130] The servo pulley 14 is configured to move freely in the vertical direction, applying a certain load downwards in the vertical direction to the wire electrode 2 using its own weight. As the tension of the wire electrode 2 changes slightly, the servo pulley 14 moves vertically, absorbing the minute vibrations generated by the wire electrode 2. A wire break detector 16 is installed along the path of the wire electrode 2 after passing the servo pulley 14 to detect breakage of the wire electrode 2.

[0131] The tension applying device 15 is configured to apply a predetermined tension to the wire electrode 2 in cooperation with the wire take-up mechanism 6. It includes a feed roller 15a, a conveying motor 15b, a tension detector 15c, and a pressure roller 15d. The feed roller 15a is driven to rotate by the conveying motor 15b. The wire electrode 2 is pressed against the outer circumferential surface of the feed roller 15a by the pressure roller 15d, thereby obtaining the driving force for movement. Furthermore, the wire electrode 2 moves along the outer circumferential surface of the feed roller 15a using multiple rollers including the pressure roller 15d. The tension detector 15c, for example, is a strain gauge, and is provided to detect the tension of the wire electrode 2. The conveying motor 15b is a servo motor, and servo control is performed based on the tension detection result obtained from the tension detector 15c. Therefore, even when the set tension value is small, the tension of the wire electrode 2 remains stable, and slackness and breakage of the wire electrode 2 can be more reliably prevented.

[0132] With the wire electrode 2 guided to the upper guide device 31a and the lower guide device 31b, a predetermined tension can be applied to the wire electrode 2 by adjusting the difference in rotational speed between the feed roller 15a and the winding roller 64a of the winding device 64. Furthermore, when wiring the wire electrode 2, the feed roller 15a rotates at a constant speed in the forward direction, causing the tip of the wire electrode 2 to pass through the lower hole and be captured by the wire recovery mechanism 6. Moreover, when rewiring the wire electrode 2, the feed roller 15a rotates at a constant speed in the reverse direction, lifting the wire electrode 2 to a predetermined position.

[0133] 1.3. Automatic wiring device 17

[0134] The automatic wiring device 17 inserts the front end of the wire electrode 2 fed from the wire supply mechanism 1 into a lower hole formed in the workpiece W, and automatically positions the wire electrode 2 between the upper wire guide 32a and the lower wire guide 32b respectively provided in the upper guide device 31a and the lower guide device 31b. The automatic wiring device 17 includes a guide tube 18 and a lifting device 19. The guide tube 18 guides the wire electrode 2 from the upstream side to the upper wire guide 32a in a manner that prevents it from detaching from a predetermined travel path. Figure 1 The diagram shows the conduit 18 positioned at its upper limit position. The conduit 18 is configured to move vertically between its upper limit position and its lower limit position, where its lower end is directly above the upper surface of the upper wire guide 32a, via a lifting device 19. The lifting device 19 moves the conduit 18 to its upper limit position when annealing or cutting the wire electrode 2, and moves it to its lower limit position when inserting the front end of the wire electrode 2 into the lower hole.

[0135] Moreover, such as Figure 1 As shown, a linear vibrating device 20 is installed directly above the inlet of the conduit 18. The linear vibrating device uses compressed air supplied from the compressed air supply device 92 to apply pressure directly or indirectly to the wire electrode 2 along its travel path. As a result, the wire electrode 2 moves slightly up and down, making it easy to pass through the lower hole.

[0136] 1.4. Wire Conductor Mechanism 3

[0137] like Figure 1 As shown, the wire guide mechanism 3 includes an upper guide device 31a and a lower guide device 31b, and is configured to position and guide the wire electrode 2 on a predetermined travel path near the workpiece W. In the following description, the structure of the lower guide device 31b will be described in detail as a specific example.

[0138] like Figure 1 As shown, the lower guide device 31b of this embodiment is constructed by incorporating a lower wire conductor 32b, a lower energizer 33b, a lower switch device for the lower energizer 33b, and a lower fixing device for the lower energizer 33b within the housing 4. The wire electrode 2 conducts power to the lower guide device 31b, which is positioned on the lower side of the workpiece W, and guides it to the wire retraction mechanism 6. Furthermore, in the following description, as... Figure 1 The vertical direction Z, the first direction D1, and the second direction D2 are determined as shown. The first direction D1 is a horizontal single-axis direction, which is the direction in which the lower current-carrying body 33b moves when it contacts or separates from the line electrode 2. The second direction D2 is another horizontal single-axis direction orthogonal to the first direction.

[0139] The lower switching device is a unit that contacts and separates the lower energized body 33b from the wire electrode 2 by reciprocating the lower energized body 33b in the first direction D1. In this invention, a predetermined position in which the lower energized body 33b contacts the wire electrode 2 is designated as a processing position, referred to as the lower energized body 33b being in the closed state. On the other hand, a predetermined position in which the lower energized body 33b is separated from the wire electrode 2 is designated as a retraction position, referred to as the lower energized body 33b being in the open state. During processing, the lower switching device moves the lower energized body 33b to the processing position to contact the wire electrode 2, for example, during automatic wiring or when the lower energized body 33b is replaced, and moves the lower energized body 33b to the retraction position. The lower fixing device is a unit that fixes the lower energized body 33b to a predetermined position within the lower guide device by reciprocating the lower energized body 33b in the first direction D1. The lower fixing device is configured to switch between the following states: a fixed state, in the second direction D2, where the lower energized body 33b cannot move relative to the lower guide device 31b; and a non-fixed state, in the second direction D2, where the lower energized body can move relative to the lower guide device. In the lower guide device 31b of this embodiment, in order to fix it while moving the lower energized body 33b to a predetermined processing position and to release it from fixation while moving the lower energized body 33b to a predetermined retraction position, the switching device and the fixing device substantially include the same components; it can be said that the fixing device also functions as a switching device.

[0140] like Figures 2 to 6 As shown, the housing 4 includes a base 41, a guide block 42, a slider 43, and a jet nozzle 44. Furthermore, from a visibility point of view, Figures 2 to 6 While some parts are omitted, O-rings or gaskets or other sealing components are appropriately installed between the components of the housing 4 to improve airtightness.

[0141] The base 41 is fixed to the front end of the lower arm (not shown). The base 41 is a component used to mount the lower guide device 31b on the lower arm and support the lower guide device 31b on the lower arm. The base 41 is disposed on the lower side of the body of the lower guide device 31b, i.e., the housing 4, and near the center, an electrode insertion hole 41a through which the wire electrode 2 is inserted is formed along the vertical direction Z. A recess 41b for receiving the guide block 42 is formed on the upper surface of the base 41.

[0142] The guide block 42 is positioned above the base 41, and a generally cylindrical protrusion 42e protruding from the lower surface is embedded in the recess 41b of the base 41. In the guide block 42, an electrode insertion hole 42a for inserting a wire electrode is formed along the vertical direction Z. Furthermore, a through hole 42b is formed along the first direction D1, and a slider 43 is inserted into the through hole 42b. Moreover, inside the guide block 42, such as... Figure 7 and Figure 8 As shown, a storage space 42d is formed by extending through the guide block 42 along the second direction D2. A flat-shaped lower-side conductive body 33b is inserted from either of the openings 42d1 or 42d2 at both ends of the storage space 42d and stored within it. A lower-side wire conductor 32b is disposed on the upper part of the guide block 42. In this embodiment, the lower-side wire conductor 32b is a cutting conductor. The lower-side wire conductor 32b includes a guide hole 32b1. The wire electrode 2 is inserted through the lower-side wire conductor 32b with a gap of several μm between the inner surfaces of the guide hole 32b1 and guided in the vertical direction Z. Furthermore, an outlet conductor 51 is disposed on the lower part of the guide block 42. The outlet conductor 51 is a cutting conductor used to guide the wire electrode 2 from the guide block 42 to the electrode insertion hole 41a of the base 41.

[0143] The slider 43 includes: a generally rectangular flat plate portion 43a, a generally cylindrical shaft 43b disposed on one of the cross-sections of a pair of opposing end faces of the flat plate portion 43a, and a cylindrical portion 43c disposed on the other end face. In the flat plate portion 43a, an electrode insertion hole 43a1 for inserting the wire electrode 2 is formed along the vertical direction Z, and a slit-shaped through hole 43a2 for inserting the lower current-carrying body 33b is formed along the second direction D2. The width of the through hole 43a2 in the first direction D1 is provided with a gap to the extent that the lower current-carrying body 33b can be inserted, and is set to be approximately the same as the thickness of the lower current-carrying body 33b in the first direction D1. Moreover, the through hole 43a2 is formed in a manner continuous with the receiving space 42d of the guide block 42. The lower conductive body 33b, inserted through the openings 42d1 and 42d2 of the guide block 42, passes through the through hole 43a2, so that the flat plate portion 43a is housed in the storage space 42d in a transversely cut state. Furthermore, the through hole 43a2 and the electrode insertion hole 43a1 are formed in a manner that repeats a portion of the space occupied by these holes. Thus, in the repeated space, the lower conductive body 33b inserted through the through hole 43a2 can contact the wire electrode 2 inserted through the electrode insertion hole 43a1.

[0144] A force-applying member 52 is wound around shaft 43b, with one end of the force-applying member 52 abutting against the covering member 53. The slider 43 applies force to the first direction D1 using the force-applying member 52. In this embodiment, the force-applying member 52 is a compression spring, and the slider 43 moves along... Figure 6 The first direction D1, specifically towards Figure 6 D1+ applied force in the middle.

[0145] An opening 43c1 is formed on the end face of the cylindrical portion 43c, and an insertion hole 43c2 is formed inside the cylindrical portion 43c, connecting the opening 43c1 to the through hole 43a2 of the flat plate portion 43a. A plunger bolt 54 is inserted into the insertion hole 43c2. The ball 54a at the front end of the plunger bolt 54 abuts against the lower energized body 33b, and the lower energized body 33b is continuously pressed along the first direction D1 toward the direction of D1- by a relatively small applied force from the internal spring 54b.

[0146] like Figures 6 to 8 As shown, a power cylinder 55 is installed in the cylindrical portion 43c. The power cylinder 55 includes a cylinder 55a and a piston 55b that can slide inside the cylinder 55a. The piston 55b is fitted into the cylindrical portion 43c of the slider 43 with the plunger bolt 54 passing through the center. In this embodiment, the power cylinder 55 is a cylinder, and the piston 55b reciprocates in the first direction D1 using the pressure of compressed air supplied via the connecting pipe 56. In addition, to prevent foreign matter from entering the cylinder 55a, a scraper 57 can be installed on the side of the cylinder 55a. Moreover, in this embodiment, a metal plate 58 is arranged on the end face of the piston 55b. If the piston 55b moves a predetermined distance in the direction of D1+, then Figure 8 In the middle, the plate 58 abuts against the cylinder 55a, thereby restricting the further movement of the piston 55b.

[0147] The jet nozzle 44 is provided for spraying pressurized machining fluid supplied from the machining fluid supply device 93 into the machining gap 10. An electrode insertion hole 44a is formed in the jet nozzle 44 for inserting a wire electrode. The base 41, guide block 42, slider 43, and the electrode insertion holes 41a, 42a, 43a1, and 44a of the jet nozzle 44 are continuously arranged in the vertical direction Z, thereby forming a travel path for the wire electrode 2 within the housing 4.

[0148] Furthermore, the upper guide device 31a can be constructed using components substantially the same as those of the lower guide device 31b, except for the base 41; detailed descriptions are omitted. In particular, the upper fixing device of the upper guide device 31a can be constructed in the same manner as the lower fixing device of the lower guide device 31b. Moreover, the wire electrical discharge machining apparatus 100 includes a so-called cone device (not shown) that allows one of the upper guide device 31a and the lower guide device 31b to move horizontally relative to the other. Through this relative movement as described above, the wire electrode 2 can be tilted relative to the workpiece W for machining.

[0149] The upper energizer 33a and lower energizer 33b, housed within the upper guide device 31a and lower guide device 31b, are movable along the first direction D1. They supply power by moving towards D1- and contacting the wire electrode 2, and stop supplying power by moving away from the wire electrode 2 from the contact state and moving towards D1+. In this embodiment, the power cylinder 55 and the force-applying member 52 within the lower guide device 31b constitute a lower-side fixing device, causing the lower energizer 33b to reciprocate along the first direction D1.

[0150] The power supply device 91 supplies power to the wire electrode 2 and the workpiece W, and includes a discharge processing circuit (not shown) comprising a DC power supply, switching elements, and a diode to prevent reverse current flow. Typically, the upper energizer 33a and the lower energizer 33b are connected to the negative terminal of the DC power supply of the power supply device 91. The positive terminal of the DC power supply is connected to the workpiece W. The upper energizer 33a and the lower energizer 33b move in a first direction D1 and come into contact with the wire electrode 2. Thereby, the power supply device 91 repeatedly applies voltage pulses to the processing gap 10 between the wire electrode 2 and the workpiece W through the upper energizer 33a, the lower energizer 33b, and the workpiece W, causing a discharge. The greater the contact between the upper energizer 33a and the lower energizer 33b and the wire electrode 2, the smaller the contact resistance at the contact point, and the greater the power supply.

[0151] 1.5. Line recycling mechanism 6

[0152] The wire recovery mechanism 6 recovers the wire electrode 2 consumed during processing from the processing gap 10. The wire recovery mechanism 6 includes: a guide roller 61, a conveying pipe 62, a suction machine 63, a winding device 64, a wire cutter 65, and a barrel 66. The wire electrode 2, guided by the lower guide device 31b, has its direction of travel changed to horizontal by the guide roller 61 and is inserted into the conveying pipe 62. The wire electrode 2 in the conveying pipe 62 is propelled by the suction machine 63.

[0153] The winding device 64 includes a winding roller 64a, a pressure roller 64b, and a winding motor 64c. The wire electrode 2, passing through the conveying tube 62, is held between the winding roller 64a and the pressure roller 64b of the winding device 64. The winding roller 64a rotates in the forward direction at a predetermined speed using the winding motor 64c, which functions as a constant-speed rotary motor, causing the wire electrode 2 to travel and be introduced directly above the barrel 66. The introduced wire electrode 2 is appropriately chopped using a wire cutter 65 and stored inside the barrel 66.

[0154] 1.6. Extrusion device 8

[0155] The wire electrical discharge machining apparatus 100 includes a pressing device 8. The pressing device 8 is configured to move relative to the lower guide device 31b, and is configured to press the lower conductive body 33b within the lower guide device 31b and move in the second direction D2. The pressing device 8 of this embodiment is as follows... Figure 9 As shown, the wire electrical discharge machining (EDM) apparatus 100 is installed in a mechanism that fixes the workpiece W. The apparatus includes: a base 21 horizontally positioned on the ground as a platform, a platform 22 mounted on the base 21, and a workstation 23 mounted on the platform 22. The workpiece W is fixed to the upper surface of the workstation 23. By simultaneously moving the upper guide device 31a and the lower guide device 31b relative to the workstation 23 in mutually orthogonal horizontal dual-axis directions, the wire electrode 2 is moved relative to the workpiece W, allowing for arbitrary adjustment of the machining position of the upper or lower surface of the workpiece W.

[0156] The extrusion device 8 includes: a body portion 81 connected to the workstation 23; and a first extrusion pin 82 continuously disposed from the body portion 81 and directed toward one of the directions of a second direction D2. Figure 9 The orientation of D2+ is prominent. By retracting the first pressing pin 82 from the opening 42d1 of the guide block 42 of the lower guide device 31b into the storage space 42d, the end face 33b1 of the lower energized body 33b is pressed by the front end of the first pressing pin 82, and the lower energized body 33b can be moved in the orientation of D2+ in the second direction.

[0157] Since the workstation 23 in this embodiment can move relatively in a horizontal dual-axis direction, it can also be used to move the workstation 23 relative to the lower guide device 31b in a horizontal single-axis direction. Figure 9 In the embodiment shown, the unit that moves relative to the workstation in the direction of the second direction D2+ serves as the moving device. Using this moving device, the pressing device 8, which is connected to and fixed to the workstation 23, can be moved relative to the lower guide device 31b in the direction of the second direction D2+. Furthermore, the main body 81 is configured to slide relative to the workstation 23 along the second direction D2. The pressing of the lower energized body 33b is performed when the workpiece W is not being processed by electrical discharge machining. During the electrical discharge machining of the workpiece W, the main body 81 is slidable or extended / retracted relative to the workstation 23, such as... Figure 10 As shown, the first pressing pin 82 can be moved to a retracted position that does not interfere with the lower guide device 31b. The drive mechanism that slides the body 81 can be, for example, a linear motor mechanism, a rack and pinion mechanism, a hydraulic cylinder, or an electric cylinder.

[0158] Furthermore, the moving device is not limited to the aforementioned structure. For example, a moving device that allows the lower guide device 31b to move horizontally can also be used to move the lower guide device 31b relative to the extrusion device 8. Moreover, for example, the relative movement of the extrusion device 8 can be achieved by combining the movement of the extrusion device 8 caused by the workstation 23 as the platform 22 moves with the movement of the lower guide device 31b caused by the movement of the column fixed by the lower arm (not shown).

[0159] Furthermore, the extrusion device 8 can also be configured to extrude the upper energized body 33a within the upper guide device 31a in addition to extruding the lower energized body 33b, thereby moving it. For example, by providing an additional extrusion pin above the workpiece W, and moving it relative to the upper guide device 31a, the front end of this extrusion pin can be used to extrude the upper energized body 33a housed within the upper guide device 31a, thereby moving it.

[0160] 2. Movement and fixation of energized bodies

[0161] Next, the movement and fixation of the energized body will be described in detail. In the following description, the movement and fixation of the lower energized body 33b will be used as a specific example for detailed explanation.

[0162] The lower energized body 33b, inserted through the opening of the guide block 42 and housed in the storage space 42d, is switched between a fixed state (where it cannot move relative to the lower guide device 31b in the second direction D2) and a non-fixed state (where it can move relative to the lower guide device 31b in the second direction D2) using a lower fixing device. In this embodiment, the power cylinder 55 and the force-applying member 52 within the lower guide device 31b constitute the lower fixing device.

[0163] Figure 6 and Figure 7The lower energized body 33b represents the fixed state. The slider 43 is subjected to force along the first direction D1 toward D1+ by the force-applying member 52. As a result, the lower energized body 33b, which is inserted in the through hole 43a2 of the slider 43, is subjected to force along the first direction D1 from the predetermined processing position to the retraction position toward the direction of separation from the wire electrode. If compressed air is supplied to the power cylinder 55, the piston 55b moves in the cylinder 55a and opposes the force applied by the force-applying member 52, causing the slider 43 to move along the first direction D1 toward D1-. Subsequently, the lower energized body 33b is extruded along the first direction D1 from the predetermined retraction position toward the direction of approaching the wire electrode 2 and fixed at the predetermined processing position. In this embodiment, by extruding the lower energized body 33b to abut against the wall surface 42f on the wire electrode 2 side of the receiving space 42d, the lower energized body 33b can be fixed relative to the lower guide device 31b. The lower energized body 33b in the fixed state is in contact with the line electrode 2, thereby supplying power to the line electrode 2.

[0164] Figure 8 The lower energized body 33b in a non-fixed state is shown. If the supply of compressed air to the power cylinder 55 is stopped, the force of the piston 55b squeezing out the slider 43 weakens. Using the force applied by the force-applying member 52, the slider 43 moves along the direction of D1+, and the lower energized body 33b is squeezed out along the first direction D1 from the predetermined processing position to the retraction position, moving away from the wire electrode 2. In this embodiment, the lower energized body 33b is squeezed out and separated from the wall 42f on the wire electrode 2 side of the receiving space 42d. Thus, the fixation is released, and the lower energized body 33b becomes a state where it can move along the second direction D2 within the receiving space 42d. The lower energized body 33b in the non-fixed state is in a state where it is not in contact with the wire electrode 2.

[0165] When the lower energized body 33b is moved, the pressing device 8 is brought close to the lower guide device 31b by the horizontal movement of the workstation 23, which serves as a moving device. Furthermore, the first pressing pin 82 is inserted from the opening 42d1 of the guide block 42 into the storage space 42d, and the front end of the first pressing pin 82 presses the end face 33b1 of the lower energized body 33b. As a result, the lower energized body 33b moves within the storage space 42d along the second direction D2 toward the direction D2+.

[0166] As described above, the lower energized body 33b is continuously pressed along the first direction D1 towards D1- by the plunger bolt 54. The applied force of the spring 54b of the plunger bolt 54 is set to be small enough not to impede the movement of the lower energized body 33b along the second direction D2 in the non-fixed state by the first pressing pin 82. Thus, in the non-fixed state, the lower energized body 33b is also pressed against the wall of the through hole 43a2 of the slider 43, which can suppress excessive movement along the second direction by the pressing of the first pressing pin 82.

[0167] The amount of movement of the lower energized body 33b can be adjusted by increasing or decreasing the extrusion amount of the first extrusion pin 82. The distance of movement of the lower energized body 33b (the distance of movement along the second direction D2 in one movement) can be appropriately set according to the outer diameter of the wire electrode 2 or the processing conditions, for example, 0.3 mm or more and 2 mm or less.

[0168] The movement of the lower energized body 33b can be performed before the start of the electrical discharge machining (EDM) or during the EDM process. In the latter case, it is preferable to perform the movement when the machining is interrupted to rewire the wire electrode 2. During EDM, the wire electrode 2 is frequently cut off and rewired during the EDM process for purposes such as changing the machining location of the workpiece W. If the lower energized body 33b is moved when the wire electrode 2 is cut off as described above, it is not necessary to interrupt the machining process solely for the purpose of moving the lower energized body 33b.

[0169] Furthermore, regarding the upper energized body 33a, an upper moving device (not shown) with the same mechanism can be used to switch between the fixed state and the non-fixed state, and it can be moved within the upper guide device 31a by means of the squeezing device 8.

[0170] By using the extrusion device 8, the lower energized body 33b can move automatically within the storage space 42d of the lower guide device 31b. Even when the workpiece W is large and the operator's hand cannot easily reach the lower guide device 31b, or when the lower guide device 31b is placed in the processing fluid for processing while immersing the workpiece W in the processing fluid, there is no need to perform operations that interrupt processing for extended periods, such as moving the workpiece W or draining the processing fluid. Since the contact state between the lower energized body 33b and the wire electrode 2 can be changed at a higher frequency, processing can continue beyond the usage limit of the lower energized body 33b, thus avoiding a decrease in processing accuracy.

[0171] Furthermore, by automating the position change of the lower energized body 33b, the manual positioning or fixing of the lower energized body 33b is no longer required, thus improving work efficiency. Moreover, the movement interval of the lower energized body 33b can be set to a finer value or freely adjusted according to processing conditions, thereby extending the lifespan of the lower energized body 33b.

[0172] Furthermore, as a moving device for moving the extrusion device 8 relative to the lower guide device 31b, the platform 22 that moves the workstation 23, or an existing mechanism for moving the guide device, can be used. There is no need to install a new drive mechanism to move the extrusion device 8, making installation easy.

[0173] 3. Control device 7

[0174] Next, the control device 7 used to control the operation of the wire electrical discharge machining (EDM) apparatus 100 will be described. The control device 7 controls the overall operation of the wire EDM apparatus 100 and the operation of each constituent device. Hereinafter, the control operation of the control device 7 will be described only in relation to the present invention. Figure 11 As shown, the control device 7 includes: an input device 71, a numerical control device 72, and a movement control device 73.

[0175] Furthermore, the components of the control device 7 can be implemented in software or hardware. In the case of software implementation, various functions can be achieved by executing computer programs through a central processing unit (CPU). The program can be stored in built-in storage or in a non-transitory recording medium readable by a computer. Moreover, programs stored in external storage can also be read, achieving this through cloud computing. In the case of hardware implementation, various circuits such as application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or dynamically reconfigurable processors (DRPs) can be used. In this embodiment, various information or concepts containing such information are processed, but these are represented as a collection of bits including binary numbers of 0 or 1 by high and low signal values, and communication or computation can be performed through the aforementioned software or hardware.

[0176] The input device 71 is used by the operator to input information required for various processes in the numerical control device 72, and may include, for example, a touch panel, keyboard, or mouse. Examples of input information include the distance or time interval of movement of the upper energizer 33a and the lower energizer 33b. The input information is output to the numerical control device 72.

[0177] The numerical control unit 72 is used to generate operating instructions for the wire electrical discharge machining (EDM) apparatus 100 using input information and a numerical control (NC) program that records machining conditions. The NDM unit 72 sets machining conditions suitable for the required EDM by reading the machining conditions recorded in the NC program or based on input information from the input device 71. The set machining conditions are output to the control units of each device and mechanism constituting the wire EDM apparatus 100 in the form of operating instruction signals or operating instruction value data.

[0178] The movement control device 73 controls the upper and lower fixing devices according to the operation command. Regarding the lower fixing device, it controls the supply of compressed air to the power cylinder 55 to switch the fixed and non-fixed states of the lower energized body 33b. Furthermore, the movement control device 73 controls the extrusion device 8 and the movement device. For example, when the platform 22 or the movement mechanism of the guide device is used as the movement device for the extrusion device 8, these devices are operated to move the extrusion device 8 relative to the lower guide device 31b. Moreover, if the extrusion device 8 is equipped with a drive mechanism for sliding the body 81, the drive mechanism is controlled to bring the extrusion device 8 closer to the lower guide device 31b or to a retracted position.

[0179] In addition, the control device 7 outputs operating commands to the control units of each device and mechanism constituting the wire electrical discharge machining apparatus 100, and receives feedback from each control unit on the actual operating information of each device and mechanism.

[0180] 4. Wire electrical discharge machining method for workpiece W

[0181] Next, focusing on the order of the lower-side energized bodies 33b, the wire discharge machining method for the workpiece W using the wire discharge machining apparatus 100 of this embodiment will be described.

[0182] First, the operator inserts the unused lower energized body 33b into either opening 42d1 or opening 42d2 of the guide block 42. The operator inputs information such as the distance or time interval of movement of the lower energized body 33b into the input device 71 of the control device 7. Then, the position of the lower energized body 33b is initialized. The lower energized body 33b is set to a non-fixed state, and while the pressing device 8 is moved relative to the lower guide device 31b, the lower energized body 33b is pressed by the first pressing pin 82, thereby moving the lower energized body 33b along the second direction D2 to the initial position within the storage space 42d.

[0183] Compressed air is supplied to the power cylinder 55, fixing the lower energizer 33b in place so that it contacts the wire electrode 2. Then, the power supply unit 91 operates according to the operating command, repeatedly applying voltage pulses to the machining gap 10 between the wire electrode 2 and the workpiece W through the upper energizer 33a and the lower energizer 33b. This causes a discharge in the machining gap 10, performing machining to the desired shape.

[0184] After the predetermined processing time has elapsed, when processing is interrupted for reasons such as changing the processing location, the lower energized body 33b is moved. Specifically, the supply of compressed air to the power cylinder 55 is stopped, and the lower energized body 33b is set to a non-fixed state. The workstation 23 is moved relative to the lower guide device 31b in a horizontal single-axis direction, and the pressing device 8 is brought close to the lower guide device 31b. The first pressing pin 82 is inserted into the storage space 42d, and the lower energized body 33b is pressed by the first pressing pin 82, causing it to move only a predetermined distance along the second direction D2.

[0185] After the movement is complete, the first pressing pin 82 is pulled out of the storage space 42d and moved to the retracted position. After wiring the wire electrode 2, compressed air is supplied to the power cylinder 55 to fix the lower energized body 33b. The unused portion of the lower energized body 33b contacts the wire electrode 2. In this state, processing begins again.

[0186] Repeat the above steps until the predetermined usage area of ​​one side of the lower energizer 33b along the second direction D2 is completely used. After one side is completely used, manually remove the lower energizer 33b and reinsert it so that the side opposite to the used side can contact the wire electrode 2. After both sides of the lower energizer 33b are completely used, replace it with an unused lower energizer 33b.

[0187] 5. Other implementation methods

[0188] The present invention can also be implemented in the following forms.

[0189] In the described embodiment, the extrusion device 8 is provided with a first extrusion pin 82 protruding toward D2+ along the second direction D2. Alternatively, a second extrusion pin 84 may be provided, protruding toward the lower energized body 33b in the opposite direction to the first extrusion pin 82. For example, as... Figure 12 As shown, a first pressing pin 82 and a second pressing pin 84 can be installed using two opposing support columns that clamp the lower guide device 31b of the workstation 23, which holds the workpiece W in place. The second pressing pin 84 is connected to the body portion 83 of the horizontally movable workstation 23, opposite the support column where the first pressing pin 82 is mounted. The second pressing pin 84 is provided in a manner that extends continuously from the body portion 83 and protrudes along the second direction D2. The first pressing pin 82 and the second pressing pin 84 are configured to clamp the lower energized body 33b in the second direction D2.

[0190] The second pressing pin 84 is inserted into the storage space 42d from the opening 42d2 of the guide block 42 of the lower guide device 31b. The end face 33b2 of the lower energized body 33b is pressed by the front end of the second pressing pin 84, thereby enabling the lower energized body 33b to move in the direction of D2- in the second direction.

[0191] In the structure described above, the lower energized body 33b can be moved directly toward the direction of D2- in the second direction by using the second pressing pin 84, thus making it easier to control the movement of the moving device.

[0192] Furthermore, while the embodiment uses a flat plate-shaped conductor, the shape of the conductor is not limited to this. The conductor can move within the storage space 42d along the second direction D2, as long as it has a predetermined length in the second direction D2. For example, a cylindrical or polygonal prism-shaped conductor can also be used.

[0193] When the fixing and moving mechanism of the lower energized body 33b in the above embodiment is applied to the upper energized body 33a, the horizontal single-axis direction (third direction) in which the upper energized body 33a moves when it contacts or separates from the wire electrode 2 can be the same as, or different from, the horizontal single-axis direction in which the lower energized body 33b moves when it contacts or separates from the wire electrode 2, i.e., the first direction D1. Similarly, the horizontal single-axis direction (fourth direction) in which the upper energized body 33a moves relative to the upper guide device 31a and is orthogonal to the third direction can be the same as, or different from, the second direction D2 in which the lower energized body 33b moves relative to the lower guide device 31b.

[0194] The preferred embodiments of the present invention have been described above, but the present invention is not limited to the described embodiments. Various design changes can be made as long as they are within the scope of the claims.

Claims

1. A wire electrical discharge machining (WEDM) apparatus, comprising a wire electrode, an upper guide device, and a lower guide device, wherein... The upper guide device and the lower guide device are respectively arranged on the upper and lower sides of the workpiece to guide the wire electrode by clamping the workpiece along the vertical direction; The lower guide device comprises: A power-conducting body, and a fixing device for fixing the power-conducting body to a predetermined position within the lower guide device; The energized body supplies power by moving in a horizontal uniaxial direction, i.e., the first direction, and coming into contact with the line electrode. The fixing device is configured to switch between the following states: in the fixed state, in another horizontal single-axis direction orthogonal to the first direction, namely the second direction, the energized body cannot move relative to the lower guide device; And in a non-fixed state, in the second direction, the energized body is movable relative to the lower guide device; and includes: The extrusion device is configured to move relative to the lower guide device and to extrude the non-fixed energized body, causing it to move in the second direction; and The moving device causes the extrusion device to move relative to the lower guide device. The fixing device is configured to allow the energized body to reciprocate in the first direction. The fixing device includes a power cylinder and a force-applying component; The force-applying component is configured to apply force to the energized body in the first direction; In the fixed state, the power cylinder, against the applied force of the force-applying member, pushes the energized body out and fixes it in a direction that approaches the wire electrode in the first direction; In the non-fixed state, the force-applying member extrudes the energized body in a direction away from the line electrode in the first direction.

2. The wire electrical discharge machining apparatus according to claim 1, wherein... The lower guide device includes a guide block; The guide block houses the energized body within an internal storage space; In the fixed state, the power cylinder pushes the energized body out, causing it to abut against the wall of the storage space and be fixed in place.

3. The wire electrical discharge machining apparatus according to claim 1, wherein... The extrusion device comprises: The main body is connected to the mobile device; And a compression pin, continuously provided from the body portion, and protruding from the body portion toward one of the second directions in such a way that its front end can abut against the energized body in the lower guide device.

4. The wire electrical discharge machining apparatus according to claim 3, wherein... The extrusion pin is configured to be able to move to a retracted position during the electrical discharge machining of the workpiece without interfering with the lower guide device.

5. The wire electrical discharge machining apparatus according to claim 3, wherein... The extrusion device uses the extrusion pin as the first extrusion pin and the main body as the first main body. It also includes: a second body portion connected to the moving device; and a second pressing pin continuously disposed from the second body portion and protruding from the second body portion in another direction in the second direction such that its front end can abut against the energized body in the lower guide device; and The first extrusion pin and the second extrusion pin are configured to clamp the energized body in the second direction.

6. The wire electrical discharge machining apparatus according to claim 1, wherein... The upper guide device includes an energizing body and a fixing device; The energizer supplies power by moving in the horizontal uniaxial direction, i.e., the third direction, and coming into contact with the line electrode; The fixing device is configured to switch between the following states: fixed state, in another horizontal single-axis direction orthogonal to the third direction, namely the fourth direction, the energized body cannot move relative to the upper guide device; And in a non-fixed state, in the fourth direction, the energized body is movable relative to the upper guide device; and includes: The extrusion device is configured to be movable relative to the upper guide device, and extrudes the non-fixed energized body to move it in the fourth direction. as well as The moving device causes the extrusion device to move relative to the upper guide device.

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