Upper / lower sub-guide and upper / lower wire guide for wire electrical discharge machine

Abstract

The present invention provides an upper sub-guide, an upper wire guide, a lower sub-guide, and a lower wire guide of a wire electric discharge machine that stably hold a wire electrode and can suppress vibration or positional deviation. An upper sub-guide is provided that includes a holding portion having a larger hole diameter than a hole diameter of an upper main guide; a lead-in wall surface that gradually narrows toward the holding portion; and a lead-out wall surface that gradually widens from the holding portion, wherein a cross section of at least a portion of the lead-in wall surface has a polygonal shape or a shape obtained by bending each side of the polygonal shape inwardly to an arc shape. Alternatively, a lower sub-guide is provided that includes a holding portion having a larger hole diameter than a hole diameter of a lower main guide; a lead-in wall surface that gradually narrows toward the holding portion; and a lead-out wall surface that gradually widens from the holding portion, wherein a cross section of at least a portion of the lead-out wall surface has a polygonal shape or a shape obtained by bending each side of the polygonal shape inwardly to an arc shape.

Description

Technical Field

[0001] The present invention relates to an upper auxiliary guide for use in a wire EDM machine, an upper wire guide including the upper auxiliary guide, a lower auxiliary guide and a lower wire guide including the lower auxiliary guide. Background Technology

[0002] In electrical discharge machining (EDM) using a wire EDM machine, wire electrodes are first inserted into a pair of wire guides that clamp the workpiece, thus setting up the wire electrodes. This process is called wire connection. The wire guides are also called eyepieces. The wire guides guide and simultaneously position the gradually advancing, parallel wire electrodes. Voltage is supplied to the set-up wire electrodes via an energizing assembly.

[0003] Hereinafter, based on the workpiece, the wire guide located upstream of the wire electrode in the direction of travel is referred to as the upper wire guide, and the guide located downstream of the wire electrode in the direction of travel is referred to as the lower wire guide. Furthermore, within the wire guide, the component that directly holds the wire electrode is referred to as the guide body. Generally, the guide body is made of an insulator with excellent wear resistance, such as diamond or sapphire.

[0004] As disclosed in Japanese Patent Publication No. 2007-283423, it is known that the through hole of the guide body is composed of the following parts: a holding portion having a diameter slightly larger than that of the wire electrode; a generally inverted conical inlet wall that gradually narrows from the inlet side of the wire electrode toward the holding portion; and a generally conical outlet wall that gradually widens from the holding portion toward the outlet side of the wire electrode. Since the conventional inlet and outlet walls have circular cross-sections, the wire electrode is supported at a point on a certain cross-section of the inlet wall and at a point on a certain cross-section of the outlet wall.

[0005] Alternatively, as disclosed in Japanese Patent Publication No. Hei 03-234421, two guide bodies can be provided on each of the upper and lower guide bodies. By using a main guide body with an aperture slightly larger than the diameter of the wire electrode and a secondary guide body with an aperture larger than the aperture of the main guide body to guide the wire electrode, the wire electrode can be held more stably. Summary of the Invention

[0006] [The problem the invention aims to solve]

[0007] To improve the stability of the conductor electrode retention and achieve high-precision machining, reducing the aperture of the guide body can be considered. However, this makes the conductor electrode difficult to insert, leading to wiring failures, and also increases the risk of wire breakage due to the increased contact area with the conductor electrode. Therefore, minimizing the diameter of the guide body is limited.

[0008] The present invention was made in view of this situation, and its object is to provide a secondary guide that stably maintains the conductor electrode and suppresses vibration or positional displacement without having a significant adverse effect on the connection rate or breakage rate.

[0009] [Technical means to solve the problem]

[0010] According to the present invention, an upper auxiliary guide is provided, located upstream of the workpiece in the traveling direction of the wire electrode in a wire electrical discharge machining (EDM) machine, and guides the wire electrode together with an upper main guide. The upper auxiliary guide includes: a holding portion having an aperture larger than that of the upper main guide; an inlet wall that gradually narrows from the inlet side of the wire electrode toward the holding portion; and an outlet wall that gradually widens from the holding portion toward the outlet side of the wire electrode. The cross-section of at least a portion of the inlet wall has a polygonal shape or a shape obtained by bending each side of the polygonal shape inward into an arc shape.

[0011] Furthermore, according to the present invention, a lower auxiliary guide is provided, located downstream of the wire electrode in the travel direction of the wire electrode in a wire EDM machine, and guiding the wire electrode together with a lower main guide. The lower auxiliary guide includes: a holding portion having an aperture larger than that of the lower main guide; an inlet wall that gradually narrows from the inlet side of the wire electrode toward the holding portion; and an outlet wall that gradually widens from the holding portion toward the outlet side of the wire electrode, wherein at least a portion of the cross-section of the outlet wall has a polygonal shape or a shape obtained by bending each side of the polygonal shape inward into an arc shape.

[0012] [The effects of the invention]

[0013] According to the upper guide member of the present invention, the wire electrode is guided along two surfaces of a polygonal shape or a shape obtained by bending the sides of the polygonal shape inward into an arc shape. That is, the wire electrode is supported at two points in a certain cross-section of the inlet wall of the upper guide member. Furthermore, according to the lower guide member of the present invention, the wire electrode is guided along two surfaces of a polygonal shape or a shape obtained by bending the sides of the polygonal shape inward into an arc shape. That is, the wire electrode is supported at two points in a certain cross-section of the outlet wall of the lower guide member. Thus, the wire electrode is stably held, thereby suppressing vibration or positional misalignment. Furthermore, higher precision machining can be achieved. Attached Figure Description

[0014] Figure 1 This is a three-dimensional view of the upper guide unit and the lower guide unit.

[0015] Figure 2This is a cross-sectional view of the upper guide unit and the lower guide unit.

[0016] Figure 3 This is a side view of the online and offline guide components.

[0017] Figure 4 yes Figure 3 Section IV-IV.

[0018] Figure 5 This indicates that the first lower guide retainer and the second lower guide retainer are separated.

[0019] Figure 6 This is a top view of the upper guide component.

[0020] Figure 7 yes Figure 6 Section VII-VII.

[0021] Figure 8 yes Figure 7 The VIII-VIII cross-sectional view shows the state where the electrode with the wire inserted is connected.

[0022] Figure 9 This is a side cross-sectional view of the upper master guide.

[0023] Figure 10 This is a side cross-sectional view of the lower main guide component.

[0024] Figure 11 This is a bottom view of the lower guide component.

[0025] Figure 12 yes Figure 11 Section XII-XII.

[0026] Figure 13 yes Figure 12 The XIII-XIII cross-sectional view shows the state with the wire electrode inserted.

[0027] Figure 14 This is a top sectional view of the upper auxiliary guide in a modified example.

[0028] Figure 15 This is a bottom sectional view of the lower auxiliary guide in a modified example.

[0029] [Explanation of Symbols]

[0030] 1: Upper guide unit

[0031] 2: Lower guide unit

[0032] 3: Launch Guide

[0033] 4: Offline guide

[0034] 11, 21: Shell

[0035] 13, 23: Power-on components

[0036] 15, 25: Jet nozzles

[0037] 31: Upper guide retainer

[0038] 33: Upper secondary guide component

[0039] 35: Upper Master Bootloader

[0040] 41: Lower guide retainer

[0041] 43: Download the master bootloader

[0042] 45: Lower secondary guide

[0043] 311, 413: Side holes

[0044] 331, 351, 431, 451: Maintaining section

[0045] 333, 353, 433, 453: Import wall surfaces

[0046] 335, 355, 435, 455: Export wall surface

[0047] 337, 357, 437, 457: Supporting components

[0048] 411: First lower guide retainer

[0049] 412: Second lower guide retainer

[0050] E: Conductor electrode

[0051] W: Workpiece Detailed Implementation

[0052] Hereinafter, embodiments of the present invention will be described using the accompanying drawings. The various modifications described below can be implemented in any combination.

[0053] Figure 1 and Figure 2The diagram shows the upper guide unit 1 and the lower guide unit 2 of the wire electrical discharge machining (EDM) machine according to this embodiment. A workpiece W is placed between the upper guide unit 1 and the lower guide unit 2, and a voltage of opposite polarity to the voltage applied to the wire electrode E is applied to the workpiece W. By moving the wire electrode E, which is positioned between the upper guide unit 1 and the lower guide unit 2, relative to the workpiece W, the workpiece W is electrically processed into the desired shape. During the EDM process, a processing fluid is supplied to the small gap between the wire electrode E and the workpiece W, i.e., the processing gap. The processing fluid is pure water or a dielectric fluid with oil as its main component.

[0054] The upper guide unit 1 includes a housing 11, a power supply assembly 13, an upper wire guide 3, and a jet nozzle 15. The housing 11 internally houses the power supply assembly 13 and the upper wire guide 3. The jet nozzle 15 is mounted on the lower surface of the housing 11. The power supply assembly 13 contacts the wire electrode E upstream of the upper wire guide 3, and a voltage is applied to the wire electrode via the power supply assembly 13. Because the power supply assembly 13 presses against the wire electrode E, the wire electrode E upstream of the upper wire guide 3 is tilted. The power supply assembly 13 is configured to move back and forth, retracting during wiring to avoid obstructing the path of the wire electrode E, and advancing after wiring to contact the wire electrode E. The upper wire guide 3 guides and positions the inserted wire electrode E. The jet nozzle 15 sprays machining fluid into the machining gap during electrical discharge machining. Furthermore, during wiring, the jet nozzle 15 guides the wire electrode E by spraying machining fluid downwards.

[0055] The lower guide unit 2 includes a housing 21, a jet nozzle 25, a wire guide 4, and an energizing assembly 23. The housing 21 internally houses the wire guide 4 and the energizing assembly 23. The jet nozzle 25 is mounted on the upper surface of the housing 21. During electrical discharge machining (EDM), the jet nozzle 25 sprays machining fluid into the machining gap. The wire guide 4 guides and positions the inserted wire electrode E. The energizing assembly 23 contacts the wire electrode E downstream of the wire guide 4, and a voltage is applied to the wire electrode via the energizing assembly 23. Because the energizing assembly 23 presses against the wire electrode E, the wire electrode E downstream of the wire guide 4 tilts. The energizing assembly 23 is configured to move back and forth, retracting during wiring to avoid obstructing the path of the wire electrode E, and advancing after wiring to contact the wire electrode E.

[0056] like Figure 3 and Figure 4As shown, the upper guide member 3 includes: an upper guide member retainer 31, an upper auxiliary guide member 33, and an upper main guide member 35. The upper guide member retainer 31 houses the upper auxiliary guide member 33 via a support member 337, and the upper main guide member 35 via a support member 357. The upper auxiliary guide member 33 and the upper main guide member 35 are the guide members that directly hold the wire electrode E, and contain insulators with excellent wear resistance such as diamond or sapphire. The support member 337 and the support member 357 contain insulators such as ceramic.

[0057] like Figure 3 and Figure 4 As shown, the lower guide 4 includes a lower guide retainer 41, a lower main guide 43, and a lower auxiliary guide 45. The lower guide retainer 41 houses the lower main guide 43 via a support member 437, and the lower auxiliary guide 45 via a support member 457. The lower main guide 43 and the lower auxiliary guide 45 are the guide bodies that directly hold the wire electrode E, and contain insulators with excellent wear resistance such as diamond or sapphire. The support members 437 and 457 contain insulators such as ceramic.

[0058] The upper guide retainer 31 may also include a side hole 311 for supplying machining fluid between the upper auxiliary guide 33 and the upper main guide 35. Similarly, the lower guide retainer 41 may also include a side hole 413 for supplying machining fluid between the lower main guide 43 and the lower auxiliary guide 45. Because the wire electrode E slides relative to the upper wire guide 3 and the lower wire guide 4, wire powder may sometimes be generated after its surface is removed. By supplying machining fluid to the side hole 311, the wire powder accumulated inside the upper wire guide 3 can be discharged from the upper auxiliary guide 33 side. Similarly, by supplying machining fluid to the side hole 413, the wire powder accumulated inside the lower wire guide 4 can be discharged from the lower auxiliary guide 45 side. The supply of machining fluid to the side holes 311 and 413 can be continuously maintained during electrical discharge machining.

[0059] like Figure 2 and Figure 4 As shown, starting from the upstream side of the traveling direction of the wire electrode E, the following components are arranged in sequence: energizing assembly 13, upper auxiliary guide 33, upper main guide 35, workpiece W, lower main guide 43, lower auxiliary guide 45, and energizing assembly 23. The upper auxiliary guide 33 and upper main guide 35 are located upstream of the traveling direction of the wire electrode E, closer to the workpiece W, and guide the wire electrode E. The lower main guide 43 and lower auxiliary guide 45 are located downstream of the traveling direction of the wire electrode E, closer to the workpiece W, and guide the wire electrode E.

[0060] The guide retainer that houses the main guide and the guide retainer that houses the secondary guide can be integrally formed or can be formed separately. In this embodiment, the upper secondary guide 33 and the upper main guide 35 are housed in an integrally formed upper guide retainer 31. The lower main guide 43 and the lower secondary guide 45 are respectively housed in a first lower guide retainer 411 and a second lower guide retainer 412, which together constitute the lower guide retainer 41. Figure 5 As shown, the first lower guide retainer 411 and the second lower guide retainer 412 can be separated. Of course, the upper auxiliary guide 33 and the upper main guide 35 can also be housed in different guide retainers, or the lower main guide 43 and the lower auxiliary guide 45 can be housed in a guide retainer formed in one piece.

[0061] Although the illustrations are omitted, for ease of assembly and disassembly, a portion of the upper guide retainer 31 and the lower guide retainer 41 may be threaded. An external thread that engages with the housing 11 of the upper guide unit 1 may be formed on the upper part of the upper guide retainer 31. Internal and external threads that engage with each other may be formed inside the first lower guide retainer 411 and on the upper part of the second lower guide retainer 412, respectively. An external thread that engages with the housing 21 of the lower guide unit 2 may be formed on the lower part of the second lower guide retainer 412.

[0062] The structure of the upper auxiliary guide 33, upper main guide 35, lower main guide 43, and lower auxiliary guide 45, which are the main bodies of the guides, will be described in detail below. Furthermore, unless otherwise specified in this specification, the cross-section of the guide body refers to a cross-section orthogonal to the insertion direction of the wire electrode E; in other words, it refers to a cross-section orthogonal to the centerline of the through hole through which the wire electrode E is inserted.

[0063] like Figure 6 and Figure 7 As shown, the upper auxiliary guide 33 includes a retaining portion 331, an inlet wall surface 333, and an outlet wall surface 335, wherein the retaining portion 331, the inlet wall surface 333, and the outlet wall surface 335 constitute a through hole. The retaining portion 331 has a diameter larger than the diameter of the upper main guide 35. The diameter of the retaining portion 331 only needs to be larger than the diameter of the upper main guide 35, for example, about 0.4 mm. The inlet wall surface 333 has a shape that gradually narrows from the inlet side of the lead electrode E toward the retaining portion 331. The outlet wall surface 335 has a generally conical shape that gradually widens from the retaining portion 331 toward the outlet side of the lead electrode E. The outlet wall surface 335 has a circular cross-section.

[0064] like Figure 8As shown, at least a portion of the cross-section of the guide wall 333 has a polygonal shape. The polygonal shape is preferably a regular polygon. Furthermore, if there are too few vertices, the upper guide member 33 will become too large. If there are too many vertices, the interior angles will become larger, and therefore, the wire electrode E is prone to shifting. Therefore, the polygonal shape is particularly preferably any one of a regular hexagon, a regular heptagon, a regular octagon, a regular nonagon, or a regular decagon. According to the upper guide member 33 of this embodiment, the wire electrode E, which is tilted by the energizing assembly 13, is guided along two faces of the polygonal shape of the guide wall 333, thus the wire electrode E is stably held.

[0065] like Figure 9 As shown, the upper main guide 35 includes a holding portion 351, an inlet wall surface 353, and an outlet wall surface 355, wherein the holding portion 351, the inlet wall surface 353, and the outlet wall surface 355 constitute a through hole. The holding portion 351 has a hole diameter slightly larger than the diameter of the lead electrode E. The hole diameter of the holding portion 351 is, for example, larger than or equal to about 5 μm and less than or equal to about 20 μm larger than the diameter of the lead electrode E. An upper wire guide 3 with an appropriate hole diameter is used according to the diameter of the lead electrode E. The inlet wall surface 353 has a generally inverted conical shape that gradually narrows from the inlet side of the lead electrode E toward the holding portion 351. The outlet wall surface 355 has a generally conical shape that gradually widens from the holding portion 351 toward the outlet side of the lead electrode E. The inlet wall surface 353 and the outlet wall surface 355 have circular cross-sections.

[0066] like Figure 10 As shown, the lower main guide 43 includes a holding portion 431, an inlet wall surface 433, and an outlet wall surface 435, wherein the holding portion 431, the inlet wall surface 433, and the outlet wall surface 435 constitute a through hole. The holding portion 431 has a hole diameter slightly larger than the diameter of the wire electrode E. The hole diameter of the holding portion 431 is, for example, larger than or equal to about 5 μm and less than or equal to about 20 μm larger than the diameter of the wire electrode E. A lower wire guide 4 with an appropriate hole diameter is used according to the diameter of the wire electrode E. The inlet wall surface 433 has a generally inverted conical shape that gradually narrows from the inlet side of the wire electrode E toward the holding portion 431. The outlet wall surface 435 has a generally conical shape that gradually widens from the holding portion 431 toward the outlet side of the wire electrode E. The inlet wall surface 433 and the outlet wall surface 435 have circular cross-sections.

[0067] like Figure 11 and Figure 12As shown, the lower auxiliary guide 45 includes a retaining portion 451, an inlet wall surface 453, and an outlet wall surface 455, wherein the retaining portion 451, the inlet wall surface 453, and the outlet wall surface 455 constitute a through hole. The retaining portion 451 has a diameter larger than the diameter of the lower main guide 43. The diameter of the retaining portion 451 only needs to be larger than the diameter of the lower main guide 43, for example, about 0.6 mm. The inlet wall surface 453 has a generally inverted conical shape that gradually narrows from the inlet side of the lead electrode E toward the retaining portion 451. The outlet wall surface 455 has a shape that gradually widens from the retaining portion 451 toward the outlet side of the lead electrode E. The inlet wall surface 453 has a circular cross-section.

[0068] like Figure 13 As shown, at least a portion of the cross-section of the lead-out wall 455 has a polygonal shape. The polygonal shape is preferably a regular polygon. Furthermore, if there are too few vertices, the lower guide 45 will become too large. If there are too many vertices, the interior angles will become large, and therefore, the wire electrode E is prone to shifting. Therefore, the polygonal shape is particularly preferably any one of a regular hexagon, regular heptagon, regular octagon, regular nonagon, or regular decagon. According to the lower guide 45 of this embodiment, the wire electrode E, which is tilted by the energizing assembly 23, is guided along two faces of the polygonal shape of the lead-out wall 455, thus the wire electrode E is stably held.

[0069] The present invention is not limited to the structure of the embodiments described above, and various modifications or applications can be made without departing from the technical concept of the present invention.

[0070] For example, such as Figure 14 As shown, at least a portion of the cross-section of the guide wall 333 of the upper guide member 33 may also have a shape obtained by bending each side of the polygonal shape inward into an arc shape, instead of the polygonal shape. Additionally, as... Figure 15 As shown, at least a portion of the cross-section of the lead-out wall 455 of the lower guide member 45 may also have a shape obtained by bending each side of the polygonal shape inward into an arc shape, instead of a polygonal shape. Even so, since the wire electrode E is guided along both surfaces, the wire electrode E is stably held. In particular, if this shape is used, the wire electrode E is guided to the corner along the arc shape, thus, more preferably, the stable holding of the wire electrode E can be achieved.

[0071] Furthermore, in each guide body of this embodiment, the inlet wall and the outlet wall are directly in contact, and the retaining portion is a flat, circular hole with substantially no height. The retaining portion may also be configured as a cylindrical hole, but from the viewpoint of preventing the wire electrode E from breaking, it is ideal to have a very small contact area with the wire electrode E; therefore, the retaining portion is preferably a flat hole.

Claims

1. An upper auxiliary guide member, located upstream of the workpiece in the travel direction of the wire electrode in a wire electrical discharge machining (EDM) machine, guides the wire electrode together with an upper main guide member, characterized in that the upper auxiliary guide member comprises: The retaining part has an aperture larger than that of the upper main guide member; The guide wall gradually narrows from the guide side of the wire electrode toward the holding part; as well as The outlet wall gradually widens from the holding portion toward the outlet side of the wire electrode. Wherein, at least a portion of the cross-section of the introduced wall surface has a polygonal shape or a shape obtained by bending each side of the polygonal shape inward into an arc shape.

2. The upper guide member according to claim 1, characterized in that, The polygon shape is any one of a regular hexagon, a regular heptagon, a regular octagon, a regular nonagon, or a regular decagon.

3. An online guide, characterized in that, include: The upper guide member according to claim 1; The upper main guide; as well as The upper guide retainer accommodates the upper secondary guide and the upper main guide.

4. The online guide according to claim 3, characterized in that, The upper guide retainer includes a side hole for supplying processing fluid between the upper auxiliary guide and the upper main guide.

5. A lower auxiliary guide member, located downstream of the workpiece in the travel direction of the wire electrode in a wire electrical discharge machining (EDM) machine, guiding the wire electrode together with a lower main guide member, characterized in that the lower auxiliary guide member comprises: The retaining part has an aperture larger than that of the lower main guide member; The guide wall gradually narrows from the guide side of the wire electrode toward the holding part; as well as The outlet wall gradually widens from the holding portion toward the outlet side of the wire electrode. Wherein, at least a portion of the cross-section of the derived wall surface has a polygonal shape or a shape obtained by bending each side of the polygonal shape inward into an arc shape.

6. The lower guide member according to claim 5, characterized in that, The polygon shape is any one of a regular hexagon, a regular heptagon, a regular octagon, a regular nonagon, or a regular decagon.

7. A line guide, characterized in that, include: The lower guide as described in claim 5; The lower master guide; as well as The lower guide retainer accommodates the lower main guide and the lower auxiliary guide.

8. The unloading guide according to claim 7, characterized in that, The lower guide retainer includes a side hole for supplying processing fluid between the lower main guide and the lower auxiliary guide.

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