Upper / lower auxiliary guide and upper / lower wire guide of wire electric discharge machine

Abstract

The 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, which can stably hold a wire electrode and suppress vibration or position offset. There is provided an upper sub-guide including: a holding portion having an aperture larger than an aperture of an upper main guide; an introduction wall surface that tapers toward the holding part; and a leading-out wall surface which gradually widens from the holding part, and wherein the cross section of at least a part of the leading-in wall surface has a polygonal shape or a shape in which each side of the polygonal shape is bent inward into an arc shape. Alternatively, provided is a lower sub-guide including: a holding portion having a larger aperture than that of the lower main guide; an introduction wall surface that tapers toward the holding part; and a leading-out wall surface which gradually widens from the holding part, in which at least a part of the cross-section of the leading-out wall surface has a polygonal shape or a shape in which each side of the polygonal shape is bent inward into an arc shape.

Description

Technical Field

[0001] The present invention relates to an upper sub-guide used in a wire electric discharge machining machine and an upper wire guide including the upper sub-guide, and a lower sub-guide and a lower wire guide including the lower sub-guide. Background Art

[0002] When performing electrical discharge machining using a wire EDM, first, a wire electrode is inserted into a pair of wire guides that are arranged to sandwich the workpiece, and the wire electrode is set up. This operation is called wiring. The wire guide is also called an eye mask. The wire guide guides and positions the wire electrode that is gradually fed out and moves. Voltage is supplied to the set wire electrode via a power supply component.

[0003] Hereinafter, based on the workpiece, the wire guide located on the upstream side of the moving direction of the wire electrode is referred to as the upper wire guide, and the guide located on the downstream side of the moving direction of the wire electrode is referred to as the lower wire guide. In addition, in the wire guide, the member 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] Here, as disclosed in Japanese Patent Laid-Open 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 hole diameter slightly larger than the diameter of the lead electrode; an inlet wall surface having a substantially inverted conical shape, which gradually narrows from the lead electrode's lead-in side toward the holding portion; and an outlet wall surface having a substantially conical shape, which gradually widens from the holding portion toward the lead electrode's lead-out side. Since the cross-sections of the conventional inlet wall surface and the outlet wall surface are both circular, the lead electrode is supported at one point in a certain cross-section of the inlet wall surface, and is supported at one point in a certain cross-section of the outlet wall surface.

[0005] In addition, as disclosed in Japanese Patent Laid-Open No. 03-234421, two guide main bodies may be provided on each of the upper wire guide and the lower wire guide. The lead electrode may be guided by a main guide having a hole diameter slightly larger than the diameter of the lead electrode and a secondary guide having a hole diameter larger than the main guide, thereby enabling the lead electrode to be held more stably. Summary of the invention

[0006] [Problems to be solved by the invention]

[0007] In order to improve the stability of the wire electrode and achieve high-precision processing, it is possible to reduce the hole diameter of the guide body. However, the wire electrode becomes difficult to insert, which makes wiring easy to fail, and there is also a disadvantage that the wire is easy to break due to the increase in the contact area with the wire electrode. Therefore, there is a limit to the reduction of the diameter of the guide body.

[0008] The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a sub-guide that can stably hold a lead electrode and suppress vibration or positional deviation without causing a significant adverse effect on a connection rate or a disconnection rate.

[0009] [Technical means to solve the problem]

[0010] According to the present invention, an upper auxiliary guide is provided, which is located on the upstream side of the travel direction of the wire electrode in a wire electric discharge machine relative to a workpiece, and guides the wire electrode together with the upper main guide, wherein the upper auxiliary guide comprises: a holding portion having an aperture larger than the aperture of the upper main guide; an introduction wall surface which gradually narrows from the introduction side of the wire electrode toward the holding portion; and an outlet wall surface which gradually widens from the holding portion toward the outlet side of the wire electrode, wherein a cross section of at least a part of the introduction wall surface has: a polygonal shape or a shape obtained by bending each side of the polygonal shape inwardly into an arc shape.

[0011] In addition, according to the present invention, there is provided a lower auxiliary guide, which is located on the downstream side of the moving direction of the wire electrode relative to the workpiece in the wire electric discharge machine, and guides the wire electrode together with the lower main guide, the lower auxiliary guide comprising: a holding portion having a hole diameter larger than the hole diameter of the lower main guide; an introduction wall surface which gradually narrows from the introduction side of the wire electrode toward the holding portion; and an outlet wall surface which gradually widens from the holding portion toward the outlet side of the wire electrode, wherein a cross section of at least a part of the outlet wall surface has: a polygonal shape or a shape obtained by bending each side of the polygonal shape inwardly into an arc shape.

[0012] [Effects of the Invention]

[0013] According to the upper sub-guide of the present invention, the wire electrode is guided along two surfaces of the polygonal shape of the lead-in wall or the shape obtained by bending each side of the polygonal shape inwardly into an arc shape. That is, the wire electrode is supported at two points in a certain section of the lead-in wall of the upper sub-guide. In addition, according to the lower sub-guide of the present invention, the wire electrode is guided along two surfaces of the polygonal shape of the lead-out wall or the shape obtained by bending each side of the polygonal shape inwardly into an arc shape. That is, the wire electrode is supported at two points in a certain section of the lead-out wall of the lower sub-guide. As a result, the wire electrode is stably held, and therefore, the occurrence of vibration or positional deviation can be suppressed. Furthermore, higher-precision processing can be achieved. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a perspective view of the upper guide unit and the lower guide unit.

[0015] Figure 2It 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 upper wire guide and the lower wire guide.

[0017] Figure 4 yes Figure 3 IV-IV cross-sectional view of the .

[0018] Figure 5 Indicates a state in which the first lower guide member fixer is separated from the second lower guide member fixer.

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

[0020] Figure 7 yes Figure 6 VII-VII section view.

[0021] Figure 8 yes Figure 7 The figure is a cross-sectional view taken along the line VIII-VIII of the embodiment of the present invention, and shows a state where a wire electrode is inserted.

[0022] Fig. 9 is a side sectional view of the upper main guide.

[0023] Fig.10 is a side sectional view of the lower main guide.

[0024] Fig.11 It is a bottom view of the lower auxiliary guide.

[0025] Fig.12 yes Fig.11 Section XII-XII of the diagram.

[0026] Fig.13 yes Fig.12 The XIII-XIII cross-sectional view shows a state where a wire electrode is inserted.

[0027] Fig.14 It is a top cross-sectional view of an upper sub-guide according to a modified example.

[0028] Fig.15 It is a bottom cross-sectional view of a lower sub-guide according to a modified example.

[0029] [Explanation of Symbols]

[0030] 1: Upper guide unit

[0031] 2: Lower guide unit

[0032] 3: Upper line guide

[0033] 4: Downline guide

[0034] 11, 21: Shell

[0035] 13, 23: Power-on components

[0036] 15, 25: Jet nozzle

[0037] 31: Upper guide fixture

[0038] 33: Upper auxiliary guide

[0039] 35: Upper main guide

[0040] 41: Lower guide holder

[0041] 43: Lower main guide

[0042] 45: Lower auxiliary guide

[0043] 311, 413: side holes

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

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

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

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

[0048] 411: First lower guide member fixer

[0049] 412: Second lower guide member fixer

[0050] E: Wire electrode

[0051] W: Workpiece DETAILED DESCRIPTION

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

[0053] Figure 1 and Figure 2The upper guide unit 1 and the lower guide unit 2 of the wire electrical discharge machine of the present embodiment are shown. A workpiece W is provided between the upper guide unit 1 and the lower guide unit 2, and a voltage having a polarity opposite to that applied to the wire electrode E is applied to the workpiece W. The wire electrode E provided between the upper guide unit 1 and the lower guide unit 2 is moved relative to the workpiece W, so that the workpiece W is electrical-discharge machined into a desired shape. During the electrical discharge machining process, a machining fluid is supplied to the machining gap, which is a small gap between the wire electrode E and the workpiece W. The machining fluid is a dielectric fluid having pure water or oil as a 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 accommodates the power supply assembly 13 and the upper wire guide 3. In addition, the jet nozzle 15 is mounted on the lower surface of the housing 11. The power supply assembly 13 contacts the wire electrode E at the upstream side of the upper wire guide 3, and a voltage is applied to the wire electrode through the power supply assembly 13. Since the power supply assembly 13 presses the wire electrode E, the wire electrode E at the upstream side of the upper wire guide 3 is tilted. The power supply assembly 13 is configured to be movable forward and backward, retreats during wiring so as not to hinder the travel path of the wire electrode E, and moves forward after the wiring is completed to contact the wire electrode E. The upper wire guide 3 guides the inserted wire electrode E and positions it. The jet nozzle 15 sprays machining fluid to the machining gap during electrical discharge machining. In addition, the jet nozzle 15 guides the wire electrode E by spraying machining fluid downward during wiring.

[0055] The lower guide unit 2 includes a housing 21, a jet nozzle 25, a lower wire guide 4, and a power supply assembly 23. The housing 21 accommodates the lower wire guide 4 and the power supply assembly 23. In addition, the jet nozzle 25 is mounted on the upper surface of the housing 21. The jet nozzle 25 sprays machining fluid to the machining gap during electrical discharge machining. The lower wire guide 4 guides and positions the inserted wire electrode E. The power supply assembly 23 contacts the wire electrode E at the downstream side of the lower wire guide 4, and applies voltage to the wire electrode through the power supply assembly 23. Since the power supply assembly 23 presses the wire electrode E, the wire electrode E at the downstream side of the lower wire guide 4 is tilted. The power supply assembly 23 is configured to be movable forward and backward, retreats during wiring so as not to hinder the travel path of the wire electrode E, and moves forward to contact the wire electrode E after the wiring is completed.

[0056] like Figure 3 and Figure 4As shown, the upper wire guide 3 includes: an upper guide holder 31, an upper sub-guide 33, and an upper main guide 35. The upper guide holder 31 accommodates the upper sub-guide 33 via a support member 337, and accommodates the upper main guide 35 via a support member 357. The upper sub-guide 33 and the upper main guide 35 are guide bodies that directly hold the wire electrode E, and are made of an insulator with excellent wear resistance such as diamond or sapphire. The support members 337 and 357 are made of an insulator such as ceramic.

[0057] like Figure 3 and Figure 4 As shown, the lower wire guide 4 includes: a lower guide holder 41, a lower main guide 43, and a lower sub-guide 45. The lower guide holder 41 accommodates the lower main guide 43 via a support member 437, and accommodates the lower sub-guide 45 via a support member 457. The lower main guide 43 and the lower sub-guide 45 are guide bodies that directly hold the wire electrode E, and are made of an insulator with excellent wear resistance such as diamond or sapphire. The support members 437 and 457 are made of an insulator such as ceramic.

[0058] The upper guide fixture 31 may include a side hole 311 for supplying machining fluid between the upper auxiliary guide 33 and the upper main guide 35. In addition, the lower guide fixture 41 may include a side hole 413 for supplying machining fluid between the lower main guide 43 and the lower auxiliary guide 45. The wire electrode E may slide relative to the upper wire guide 3 and the lower wire guide 4, and wire powder with the surface shaved may be generated. By supplying machining fluid to the side hole 311, the wire powder accumulated in the upper wire guide 3 can be discharged from the upper auxiliary guide 33 side. In addition, by supplying machining fluid to the side hole 413, the wire powder accumulated in the lower wire guide 4 can be discharged from the lower auxiliary guide 45 side. The machining fluid may be always supplied to the side hole 311 and the side hole 413 during the electrical discharge machining.

[0059] like Figure 2 and Figure 4 As shown in the figure, starting from the upstream side in the travel direction of the wire electrode E, the power supply unit 13, the upper sub-guide 33, the upper main guide 35, the workpiece W, the lower main guide 43, the lower sub-guide 45, and the power supply unit 23 are arranged in this order. The upper sub-guide 33 and the upper main guide 35 are located on the upstream side of the travel direction of the wire electrode E than the workpiece W, and guide the wire electrode E. The lower main guide 43 and the lower sub-guide 45 are located on the downstream side of the travel direction of the wire electrode E than the workpiece W, and guide the wire electrode E.

[0060] The guide member holder for accommodating the main guide member and the guide member holder for accommodating the auxiliary guide member may be formed integrally or separately. In this embodiment, the upper auxiliary guide member 33 and the upper main guide member 35 are accommodated in the upper guide member holder 31 formed integrally. The lower main guide member 43 and the lower auxiliary guide member 45 are accommodated in the first lower guide member holder 411 and the second lower guide member holder 412, respectively. The first lower guide member holder 411 and the second lower guide member holder 412 constitute the lower guide member holder 41. Figure 5 As shown, the first lower guide member holder 411 and the second lower guide member holder 412 can be separated. Of course, the upper secondary guide member 33 and the upper main guide member 35 can also be accommodated in different guide member holders, or the lower main guide member 43 and the lower secondary guide member 45 can be accommodated in an integrally formed guide member holder.

[0061] Although not shown in the figure, for the convenience of loading and unloading, a part of the upper guide fixture 31 and the lower guide fixture 41 may be threaded. An external thread that is screwed with the housing 11 of the upper guide unit 1 may be formed on the upper portion of the upper guide fixture 31. Internal threads and external threads that are screwed with each other may be formed inside the first lower guide fixture 411 and on the upper portion of the second lower guide fixture 412, respectively. An external thread that is screwed with the housing 21 of the lower guide unit 2 may be formed on the lower portion of the second lower guide fixture 412.

[0062] The following describes in detail the structures of the upper sub-guide 33, the upper main guide 35, the lower main guide 43, and the lower sub-guide 45 as the guide body. In addition, in this specification, unless otherwise specified, the cross section of the guide body refers to a cross section perpendicular to the insertion direction of the lead electrode E, in other words, a cross section perpendicular to the center line of the through hole through which the lead electrode E is inserted.

[0063] like Figure 6 and Figure 7 As shown in FIG. 1 , the upper secondary guide 33 includes a holding portion 331, an introduction wall surface 333, and an outlet wall surface 335, wherein the holding portion 331, the introduction wall surface 333, and the outlet wall surface 335 constitute a through hole. The holding portion 331 has a hole diameter larger than the hole diameter of the upper main guide 35. The hole diameter of the holding portion 331 only needs to be larger than the hole diameter of the upper main guide 35, for example, about 0.4 mm. The introduction wall surface 333 has a shape that gradually narrows from the introduction side of the lead electrode E toward the holding portion 331. The outlet wall surface 335 has a substantially conical shape that gradually expands from the holding 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, the cross section of at least a portion of the introduction wall surface 333 has a polygonal shape. The polygonal shape is preferably a regular polygon. In addition, if there are too few vertices, the upper auxiliary guide 33 will be large. If there are too many vertices, the internal angle becomes large, so the wire electrode E is easily offset. Therefore, the polygonal shape is particularly preferably any one of a regular hexagon, a regular heptagon, a regular octagon, a regular pentagon, and a regular decagon. According to the upper auxiliary guide 33 of this embodiment, the wire electrode E tilted by the current supply component 13 is guided along the two faces of the polygonal shape of the introduction wall surface 333, so the wire electrode E is stably maintained.

[0065] like Fig. 9 As shown in FIG. 1 , the upper main guide 35 includes a holding portion 351, an introduction wall surface 353, and an outlet wall surface 355, wherein the holding portion 351, the introduction 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 wire electrode E. The hole diameter of the holding portion 351 is larger than the diameter of the wire electrode E, for example, in a range of about 5 μm or more and about 20 μm or less. An upper wire guide 3 having an appropriate hole diameter is used according to the diameter of the wire electrode E. The introduction wall surface 353 has a substantially inverted conical shape that gradually narrows from the introduction side of the wire electrode E toward the holding portion 351. The outlet wall surface 355 has a substantially conical shape that gradually expands from the holding portion 351 toward the outlet side of the wire electrode E. The introduction wall surface 353 and the outlet wall surface 355 have a circular cross section.

[0066] like Fig.10 As shown in FIG. 1 , the lower main guide 43 includes a holding portion 431, an introduction wall surface 433, and an outlet wall surface 435, wherein the holding portion 431, the introduction 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 larger than the diameter of the wire electrode E, for example, in a range of about 5 μm or more and about 20 μm or less. Depending on the diameter of the wire electrode E, a lower wire guide 4 with an appropriate hole diameter is used. The introduction wall surface 433 has a substantially inverted conical shape that gradually narrows from the introduction side of the wire electrode E toward the holding portion 431. The outlet wall surface 435 has a substantially conical shape that gradually expands from the holding portion 431 toward the outlet side of the wire electrode E. The introduction wall surface 433 and the outlet wall surface 435 have a circular cross section.

[0067] like Fig.11 and Fig.12As shown in FIG. 1 , the lower secondary guide 45 includes a holding portion 451, an introduction wall 453, and an outlet wall 455, wherein the holding portion 451, the introduction wall 453, and the outlet wall 455 constitute a through hole. The holding portion 451 has a hole diameter larger than the hole diameter of the lower main guide 43. The hole diameter of the holding portion 451 only needs to be larger than the hole diameter of the lower main guide 43, for example, about 0.6 mm. The introduction wall 453 has a substantially inverted conical shape that gradually narrows from the introduction side of the lead electrode E toward the holding portion 451. The outlet wall 455 has a shape that gradually expands from the holding portion 451 toward the outlet side of the lead electrode E. The introduction wall 453 has a circular cross section.

[0068] like Fig.13 As shown, the cross section of at least a part of the lead-out wall surface 455 has a polygonal shape. The polygonal shape is preferably a regular polygon. In addition, if there are too few vertices, the lower sub-guide 45 will be large. If there are too many vertices, the internal angle becomes large, so the lead electrode E is easily offset. Therefore, the polygonal shape is particularly preferably any one of a regular hexagon, a regular heptagon, a regular octagon, a regular enneagon, and a regular decagon. According to the lower sub-guide 45 of this embodiment, the lead electrode E tilted by the current-carrying component 23 is guided along the two faces of the polygonal shape of the lead-out wall surface 455, so that the lead electrode E is stably held.

[0069] The present invention is not limited to the configuration of the above-described embodiment, and various modifications and applications are possible without departing from the technical concept of the present invention.

[0070] For example, Fig.14 As shown in FIG. 1 , at least a portion of the cross section of the introduction wall surface 333 of the upper auxiliary guide member 33 may have a shape obtained by bending each side of the polygonal shape inwardly into an arc shape, instead of the polygonal shape. Fig.15 As shown in FIG. 1 , the cross section of at least a portion of the lead-out wall surface 455 of the lower auxiliary guide 45 may have a shape in which each side of the polygonal shape is bent inwardly into an arc shape instead of a polygonal shape. Even in this case, since the lead electrode E is guided along two surfaces, the lead electrode E is stably held. In particular, if this shape is adopted, the lead electrode E is guided along the arc shape to the corner, so that the lead electrode E can be more stably held.

[0071] In each guide body of the present embodiment, the inlet wall surface and the outlet wall surface are directly connected, and the holding portion is a circular hole with substantially no height. The holding portion may be configured as a cylindrical hole, but from the viewpoint of preventing the wire electrode E from being disconnected, it is ideal that the contact area with the wire electrode E is extremely small, and therefore, the holding portion is preferably a flat hole.

Claims

1. An upper auxiliary guide, located on the upstream side of a wire electrode in a moving direction of a workpiece in a wire electric discharge machine, and guiding the wire electrode together with an upper main guide, wherein the upper auxiliary guide comprises: a retaining portion having a larger aperture than that of the upper main guide; an introduction wall surface that gradually narrows from the introduction side of the wire electrode toward the holding portion; as well as The lead-out wall surface gradually widens from the holding portion toward the lead-out side of the lead electrode. The cross section of at least a portion of the introduction wall surface has a polygonal shape or a shape in which each side of the polygonal shape is bent inwardly into an arc shape.

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

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

4. The upper wire guide according to claim 3, characterized in that: The upper guide member holder includes a side hole for supplying a machining fluid between the upper sub-guide member and the upper main guide member.

5. A lower auxiliary guide, located on the downstream side of the wire electrode in the traveling direction of the workpiece in a wire electric discharge machine, and guiding the wire electrode together with a lower main guide, wherein the lower auxiliary guide comprises: a retaining portion having a larger aperture than that of the lower main guide; an introduction wall surface that gradually narrows from the introduction side of the wire electrode toward the holding portion; as well as The lead-out wall surface gradually widens from the holding portion toward the lead-out side of the lead electrode. The cross section of at least a portion of the lead-out wall surface has a polygonal shape or a shape in which each side of the polygonal shape is bent inwardly into an arc shape.

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

7. A lower wire guide, characterized in that: include: The lower auxiliary guide member as claimed in claim 5; the lower main guide; as well as The lower guide member fixer accommodates the lower main guide member and the lower auxiliary guide member.

8. The lower wire guide according to claim 7, characterized in that: The lower guide member holder includes a side hole for supplying a machining fluid between the lower main guide member and the lower auxiliary guide member.

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