JP2025070071A - Upper sub-guide, upper wire guide, lower sub-guide and lower wire guide - Google Patents

Abstract

To provide a sub guide which can stably hold a wire electrode and inhibit vibration and positional deviation.SOLUTION: An upper sub guide 33 is provided including: a holding part having a bore diameter larger than a bore diameter of an upper main guide 35; an introduction wall surface which gradually narrows toward the holding part; and a lead-out wall surface which gradually widens from the holding part. In the upper sub guide 33, a cross section of at least a part of the introduction wall surface has a polygonal shape or a shape in which each side of the polygonal shape is curved inward in an arc shape. Alternatively, a lower sub guide 45 is provided including: a holding part having a bore diameter larger than a bore diameter of a lower main guide 43; an introduction wall surface which gradually narrows toward the holding part; and a lead-out wall surface which gradually widens from the holding part. In the lower sub guide 45, a cross section of at least a part of the lead-out wall surface has a polygonal shape or a shape in which each side of the polygonal shape is curved inward in an arc shape.SELECTED DRAWING: Figure 4

Description

The present invention relates to an upper subguide and an upper wire guide equipped with the upper subguide, and a lower subguide and a lower wire guide equipped with the lower subguide, which are used in a wire electric discharge machine.

When performing electric discharge machining using a wire electric discharge machine, the wire electrode is first inserted into a pair of wire guides that sandwich the workpiece, and the wire electrode is stretched. This process is called wiring. The wire guides guide and position the wire electrode as it is gradually unwound and travels. A voltage is supplied to the stretched wire electrode via an electric current. Hereinafter, the wire guide on the upstream side of the wire electrode's travel direction, based on the workpiece, will be called the upper wire guide, and the guide on the downstream side of the wire electrode's travel direction will be called the lower wire guide. In addition, the member of the wire guide that directly holds the wire electrode will be called the guide body. In general, the guide body is made of an insulator with excellent wear resistance, such as diamond or sapphire.

As disclosed in Patent Document 1, it is known that the through hole of the guide body is composed of a holding section having a hole diameter slightly larger than the diameter of the wire electrode, an inlet wall surface having a generally inverted cone shape that gradually narrows from the inlet side of the wire electrode toward the holding section, and an outlet wall surface having a generally cone shape that gradually widens from the holding section toward the outlet side of the wire electrode. Since the conventional inlet wall surface and outlet wall surface both have a circular cross section, the wire electrode is supported at one point on a cross section of the inlet wall surface and at one point on a cross section of the outlet wall surface.

As disclosed in Patent Document 2, two guide bodies may be provided on each of the upper wire guide and the lower wire guide. By guiding the wire electrode with a main guide having a hole diameter slightly larger than the diameter of the wire electrode and a sub-guide having a hole diameter larger than the hole diameter of the main guide, the wire electrode can be held more stably.

JP 2007-283423 A Japanese Patent Application Publication No. 03-234421

In order to improve the stability of the wire electrode retention and achieve high-precision machining, it is possible to reduce the hole diameter of the guide body. However, this would make it more difficult to insert the wire electrode, making connection more likely to fail, and would also have the disadvantage of making the wire more likely to break due to the increased contact area with the wire electrode. Therefore, there is a limit to how small the diameter of the guide body can be.

The present invention was made in consideration of these circumstances, and aims to provide a subguide that can stably hold a wire electrode and suppress vibration and misalignment without significantly affecting the connection rate or breakage rate.

According to the present invention, in a wire electric discharge machine, there is provided an upper sub-guide that is located upstream of the workpiece in the traveling direction of the wire electrode and guides the wire electrode together with the main guide, the upper sub-guide having a holding section with a hole diameter larger than the hole diameter of the upper main guide, an introduction wall surface that gradually narrows from the introduction side of the wire electrode toward the holding section, and an outlet wall surface that gradually widens from the holding section toward the outlet side of the wire electrode, and at least a portion of the cross section of the introduction wall surface has a polygonal shape or a shape in which each side of the polygonal shape is curved inwardly in an arc shape.

The present invention also provides a lower sub-guide for a wire electric discharge machine, which is located downstream of the workpiece in the traveling direction of the wire electrode and guides the wire electrode together with the lower main guide, and which has a holding section with a hole diameter larger than the hole diameter of the lower main guide, an introduction wall surface that gradually narrows from the introduction side of the wire electrode toward the holding section, and an introduction wall surface that gradually widens from the holding section toward the introduction side of the wire electrode, and at least a portion of the cross section of the introduction wall surface has a polygonal shape or a shape in which each side of the polygonal shape is curved inward in an arc shape.

According to the upper subguide of the present invention, the wire electrode is guided along two surfaces of a polygonal shape on the introduction wall surface or a shape in which each side of the polygonal shape is curved inwardly in an arc shape. In other words, in a cross section of the introduction wall surface of the upper subguide, the wire electrode is supported at two points. According to the lower subguide of the present invention, the wire electrode is guided along two surfaces of a polygonal shape on the introduction wall surface or a shape in which each side of the polygonal shape is curved inwardly in an arc shape. In other words, in a cross section of the introduction wall surface of the lower subguide, the wire electrode is supported at two points. This allows the wire electrode to be held stably, suppressing the occurrence of vibration and positional deviation. Ultimately, higher precision machining can be achieved.

FIG. 2 is a perspective view of an upper guide unit and a lower guide unit. 4 is a cross-sectional view of an upper guide unit and a lower guide unit. FIG. FIG. 2 is a side view of the upper wire guide and the lower wire guide. FIG. 4 is a cross-sectional view taken along line IV-IV of FIG. 13 shows a state in which the first lower guide holder and the second lower guide holder are separated. FIG. FIG. 7 is a cross-sectional view taken along line VII-VII of FIG. 8 is a cross-sectional view taken along line VIII-VIII of FIG. 7, showing a state in which the wire electrode has been inserted. FIG. 4 is a side cross-sectional view of the upper main guide. FIG. 4 is a side cross-sectional view of the lower main guide. FIG. This is a cross-sectional view taken along line XII-XII of FIG. 13 is a cross-sectional view taken along line XIII-XIII in FIG. 12, showing a state in which the wire electrode has been inserted. FIG. 11 is a top cross-sectional view of an upper sub-guide of a modified example. 13 is a bottom cross-sectional view of a lower sub-guide of a modified example. FIG.

The following describes an embodiment of the present invention with reference to the drawings. The various modifications described below can be implemented in any combination.

Figures 1 and 2 show the upper guide unit 1 and lower guide unit 2 of the wire electric discharge machine of this embodiment. A workpiece W is placed between the upper guide unit 1 and the lower guide unit 2, and a voltage of the opposite polarity to that applied to the wire electrode E is applied. The wire electrode E, which is stretched between the upper guide unit 1 and the lower guide unit 2, is moved relative to the workpiece W, and the workpiece W is electric discharge machined into the desired shape. A machining fluid is supplied to the machining gap, which is a small gap between the wire electrode E and the workpiece W, during electric discharge machining. The machining fluid is a dielectric fluid whose main component is pure water or oil.

The upper guide unit 1 includes a housing 11, a conducting member 13, an upper wire guide 3, and a jet nozzle 15. The housing 11 accommodates the conducting member 13 and the upper wire guide 3. The jet nozzle 15 is attached to the lower surface of the housing 11. The conducting member 13 contacts the wire electrode E upstream of the upper wire guide 3, and a voltage is applied to the wire electrode through the conducting member 13. The conducting member 13 presses the wire electrode E, so that the wire electrode E upstream of the upper wire guide 3 is inclined. The conducting member 13 is configured to be able to move forward and backward, and moves backward during connection so as not to interfere with the path of the wire electrode E, and moves forward after connection is completed 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 electric discharge machining. In addition, the jet nozzle 15 guides the wire electrode E by spraying machining fluid downward during connection.

The lower guide unit 2 includes a housing 21, a jet nozzle 25, a lower wire guide 4, and a conducting member 23. The housing 21 accommodates the lower wire guide 4 and the conducting member 23. The jet nozzle 25 is attached to the upper surface of the housing 21. The jet nozzle 25 sprays machining fluid into the machining gap during electric discharge machining. The lower wire guide 4 guides and positions the inserted wire electrode E. The conducting member 23 contacts the wire electrode E downstream of the lower wire guide 4, and a voltage is applied to the wire electrode through the conducting member 13. The conducting member 23 presses the wire electrode E, so that the wire electrode E downstream of the lower wire guide 4 is inclined. The conducting member 23 is configured to be able to move forward and backward, and during connection, it moves backward so as not to obstruct the path of the wire electrode E, and moves forward and contacts the wire electrode E after connection is completed.

As shown in Figures 3 and 4, 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.

As shown in Figures 3 and 4, 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.

The upper guide holder 31 may include a side hole 311 for supplying machining fluid between the upper sub-guide 33 and the upper main guide 35. The lower guide holder 41 may include a side hole 413 for supplying machining fluid between the lower main guide 43 and the lower sub-guide 45. When the wire electrode E slides against the upper wire guide 3 and the lower wire guide 4, wire powder may be generated due to the surface being scraped off. 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 sub-guide 33 side. 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 sub-guide 45 side. The supply of machining fluid to the side holes 311 and 413 may be always performed during electric discharge machining.

As shown in Figures 2 and 4, the conductive member 13, upper sub-guide 33, upper main guide 35, workpiece W, lower main guide 43, lower sub-guide 45, and conductive member 23 are arranged in this order from the upstream side in the traveling direction of the wire electrode E. The upper sub-guide 33 and upper main guide 35 are located upstream of the workpiece W in the traveling direction of the wire electrode E and guide the wire electrode E. The lower main guide 43 and lower sub-guide 45 are located downstream of the workpiece W in the traveling direction of the wire electrode E and guide the wire electrode E.

The guide holder that houses the main guide and the guide holder that houses the subguide may be integrally formed or separably formed. In this embodiment, the upper subguide 33 and the upper main guide 35 are housed in the upper guide holder 31 that is integrally formed. The lower main guide 43 and the lower subguide 45 are housed in the first lower guide holder 411 and the second lower guide holder 412, respectively, and the first lower guide holder 411 and the second lower guide holder 412 constitute the lower guide holder 41. As shown in FIG. 5, the first lower guide holder 411 and the second lower guide holder 412 are separable. Of course, the upper subguide 33 and the upper main guide 35 may be housed in different guide holders, and the lower main guide 43 and the lower subguide 45 may be housed in a guide holder that is integrally formed.

Although not shown, to facilitate attachment and detachment, parts of the upper guide holder 31 and the lower guide holder 41 may be threaded. The upper part of the upper guide holder 31 may be formed with a male thread that screws into the housing 11 of the upper guide unit 1. The inside of the first lower guide holder 411 and the upper part of the second lower guide holder 412 may be formed with a female thread and a male thread that screws into each other, respectively. The lower part of the second lower guide holder 412 may be formed with a male thread that screws into the housing 21 of the lower guide unit 2.

The configuration of the guide body, which consists of the upper sub-guide 33, the upper main guide 35, the lower main guide 43, and the lower sub-guide 45, will be described in detail below. 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 wire electrode E, in other words, a cross section perpendicular to the center line of the through hole through which the wire electrode E is inserted.

6 and 7, the upper sub-guide 33 has a holding portion 331, an introduction wall surface 333, and an exit wall surface 335, and the holding portion 331, the introduction wall surface 333, and the exit wall surface 335 form 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, and is, for example, about 0.4 mm. The introduction wall surface 333 has a shape that gradually narrows from the introduction side of the wire electrode E toward the holding portion 331. The exit wall surface 335 has an approximately conical shape that gradually widens from the holding portion 331 toward the exit side of the wire electrode E. The exit wall surface 335 has a circular cross section.

As shown in FIG. 8, at least a portion of the cross section of the introduction wall surface 333 has a polygonal shape. The polygonal shape is preferably a regular polygon. Furthermore, if there are too few vertices, the upper sub-guide 33 becomes large. If there are too many vertices, the interior angles become large, making it easier for the wire electrode E to shift. Therefore, it is preferable that the polygonal shape is particularly a regular hexagon, regular heptagon, regular octagon, regular nonagon, or regular decagon. According to the upper sub-guide 33 of this embodiment, the wire electrode E tilted by the conductive member 13 is guided along two faces of the polygonal shape of the introduction wall surface 333, so that the wire electrode E is stably held.

9, the upper main guide 35 has a holding portion 351, an introduction wall surface 353, and an exit wall surface 355, and the holding portion 351, the introduction wall surface 353, and the exit wall surface 355 form 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 the range of about 5 μm to about 20 μm. Depending on the diameter of the wire electrode E, an upper wire guide 3 with an appropriate hole diameter is used. The introduction wall surface 353 has a substantially inverted cone shape that gradually narrows from the introduction side of the wire electrode E toward the holding portion 351. The exit wall surface 355 has a substantially cone shape that gradually widens from the holding portion 351 toward the exit side of the wire electrode E. The introduction wall surface 353 and the exit wall surface 355 have a circular cross section.

10, the lower main guide 43 has a holding portion 431, an introduction wall surface 433, and an exit wall surface 435, and the holding portion 431, the introduction wall surface 433, and the exit wall surface 435 form 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 the range of about 5 μm to about 20 μm. A lower wire guide 4 with an appropriate hole diameter is used according to the diameter of the wire electrode E. The introduction wall surface 433 has a substantially inverted cone shape that gradually narrows from the introduction side of the wire electrode E toward the holding portion 431. The exit wall surface 435 has a substantially cone shape that gradually widens from the holding portion 431 toward the exit side of the wire electrode E. The introduction wall surface 433 and the exit wall surface 435 have a circular cross section.

11 and 12, the lower sub-guide 45 has a holding portion 451, an introduction wall surface 453, and an exit wall surface 455, and the holding portion 451, the introduction wall surface 453, and the exit wall surface 455 form 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, and is, for example, about 0.6 mm. The introduction wall surface 453 has a substantially inverted cone shape that gradually narrows from the introduction side of the wire electrode E toward the holding portion 451. The exit wall surface 455 has a shape that gradually widens from the holding portion 451 toward the exit side of the wire electrode E. The introduction wall surface 453 has a circular cross section.

As shown in FIG. 13, at least a portion of the cross section of the lead-out wall surface 455 has a polygonal shape. The polygonal shape is preferably a regular polygon. Furthermore, if there are too few vertices, the lower sub-guide 45 becomes large. If there are too many vertices, the interior angles become large, making it easier for the wire electrode E to shift. Therefore, it is preferable that the polygonal shape is particularly a regular hexagon, regular heptagon, regular octagon, regular nonagon, or regular decagon. According to the lower sub-guide 45 of this embodiment, the wire electrode E tilted by the conductive member 23 is guided along two faces of the polygonal shape of the lead-out wall surface 455, so that the wire electrode E is stably held.

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

For example, as shown in FIG. 14, at least a portion of the cross section of the introduction wall surface 333 of the upper sub-guide 33 may have a shape in which each side of the polygonal shape is curved inwardly in an arc shape, instead of a polygonal shape. Also, as shown in FIG. 15, at least a portion of the cross section of the extraction wall surface 455 of the lower sub-guide 45 may have a shape in which each side of the polygonal shape is curved inwardly in an arc shape, instead of a polygonal shape. Even in this way, the wire electrode E is guided along two surfaces, so the wire electrode E is stably held.

In addition, in each guide body in this embodiment, the outlet wall surfaces are in direct contact with each other, and the holding portion is a planar circular hole that has virtually no height. The holding portion may be configured as a cylindrical hole, but from the viewpoint of preventing breakage of the wire electrode E, it is desirable for the contact area with the wire electrode E to be as small as possible, so it is preferable for the holding portion to be a planar hole.

3 Upper wire guide 31 Upper guide holder 311 Side hole 33 Upper sub-guide 331 Holding portion 333 Introduction wall surface 335 Lead-out wall surface 35 Upper main guide 4 Lower wire guide 41 Lower guide holder 413 Side hole 43 Lower main guide 45 Lower sub-guide 451 Holding portion 453 Introduction wall surface 455 Lead-out wall surface E Wire electrode W Workpiece

According to the present invention, in a wire electric discharge machine, an upper sub-guide is provided which is located upstream of the workpiece in the traveling direction of the wire electrode and guides the wire electrode together with the upper main guide, the upper sub-guide having a holding portion having a hole diameter larger than the hole diameter 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 introduction wall surface which gradually widens from the holding portion toward the introduction side of the wire electrode, and at least a portion of the cross section of the introduction wall surface has a polygonal shape or a shape in which each side of the polygonal shape is curved inward in an arc shape.

The lower guide unit 2 includes a housing 21, a jet nozzle 25, a lower wire guide 4, and a conducting member 23. The housing 21 accommodates the lower wire guide 4 and the conducting member 23 inside. The jet nozzle 25 is attached to the upper surface of the housing 21. The jet nozzle 25 jets machining fluid into the machining gap during electric discharge machining. The lower wire guide 4 guides and positions the inserted wire electrode E. The conducting member 23 contacts the wire electrode E downstream of the lower wire guide 4, and a voltage is applied to the wire electrode through the conducting member 23. The conducting member 23 presses the wire electrode E, so that the wire electrode E downstream of the lower wire guide 4 is inclined. The conducting member 23 is configured to be able to move forward and backward, and during connection, it moves backward so as not to obstruct the path of the wire electrode E, and moves forward and contacts the wire electrode E after connection is completed.

In the present embodiment, the introduction wall surface and the exit wall surface of each guide body are in direct contact with each other, and the holding portion is a planar circular hole that has substantially no height. The holding portion may be configured as a cylindrical hole, but from the viewpoint of preventing breakage of the wire electrode E, it is preferable that the contact area with the wire electrode E is as small as possible, and therefore it is preferable that the holding portion is a planar hole.

Claims (8)

In a wire electric discharge machine, an upper sub-guide is located upstream of a workpiece in a traveling direction of a wire electrode, and guides the wire electrode together with an upper main guide,
a holding portion having a hole diameter larger than the hole diameter of the upper main guide;
an introduction wall surface that gradually narrows from an introduction side of the wire electrode toward the holding portion;
a lead-out wall surface that gradually widens from the holding portion toward the lead-out side of the wire electrode,
An upper sub-guide, wherein a 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 curved inwardly in an arc shape. The upper subguide according to claim 1, wherein the polygonal shape is one of a regular hexagon, a regular heptagon, a regular octagon, a regular nonagon, and a regular decagon. An upper sub-guide according to claim 1 ;
The upper main guide;
and an upper guide holder that houses the upper sub-guide and the upper main guide. The upper wire guide of claim 3, wherein the upper guide holder includes a side hole for supplying processing fluid between the upper sub-guide and the upper main guide. In a wire electric discharge machine, a lower sub-guide is located downstream of a workpiece in a traveling direction of a wire electrode, and guides the wire electrode together with a lower main guide,
a holding portion having a hole diameter larger than the hole diameter of the lower main guide;
an introduction wall surface that gradually narrows from an introduction side of the wire electrode toward the holding portion;
a lead-out wall surface that gradually widens from the holding portion toward the lead-out side of the wire electrode,
A lower sub-guide, wherein a cross section of at least a portion of the outlet wall surface has a polygonal shape or a shape in which each side of the polygonal shape is curved inwardly in an arc shape. The lower subguide according to claim 5, wherein the polygonal shape is one of a regular hexagon, a regular heptagon, a regular octagon, a regular nonagon, and a regular decagon. A lower sub-guide according to claim 5;
The lower main guide;
a lower guide holder that houses the lower main guide and the lower sub-guide. The lower wire guide of claim 7, wherein the lower guide holder includes a side hole for supplying machining fluid between the lower main guide and the lower sub-guide.

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