Wire guide and wire electrode

Abstract

The purpose is to provide a wire guide used in electrical discharge machining (EDM) with an EDM machine that prevents wear on the wire guide tip, suppresses the occurrence of abnormal discharges, and enables stable EDM operation. [Solution] The wire guide comprises a first cylindrical body having a first end, a second end located at the other end of the first end, and a first through-hole provided from the first end to the second end; a second cylindrical body having a third end, a fourth end located at the other end of the third end, and a second through-hole provided from the third end to the fourth end, located inside the first through-hole at the second end, and overlapping with the first through-hole in a plan view from the first end side; the fourth end of the second cylindrical body is recessed from the second end towards the first end in the longitudinal direction extending from the first end to the second end.

Description

Technical Field

[0001] The present disclosure relates to a wire guide and a wire electrode. In particular, the present disclosure relates to a wire guide and a wire electrode for use in electric discharge machines.

Background Art

[0002] Conventionally, electric discharge machines that generate an electric discharge phenomenon with a workpiece to perform cutting or the like on the workpiece are known. The electric discharge machine is equipped with a wire guide and a wire electrode that support a linear wire (electrode wire) that is brought close to the workpiece to generate the electric discharge phenomenon (see Patent Document 1 and Patent Document 2).

[0003] The wire guide mainly includes a substantially cylindrical first cylindrical body made of a metal material such as SUS, and a second cylindrical body fitted to one end side of the first cylindrical body and made of a ceramic material or the like. The first cylindrical body has a first through-hole penetrating therethrough, and the second cylindrical body has a second through-hole penetrating therethrough and communicating with the first through-hole. The wire inserted through the first through-hole and the second through-hole and extending from the tip of the wire guide is supported and brought close to the workpiece to be machined, and an electric discharge phenomenon is generated, whereby electric discharge machining is performed on the workpiece.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Summary of Invention

Problems to be Solved by the Invention

[0005] During electrical discharge machining (EDM), the second cylinder at the tip of the wire guide is exposed to high-voltage electrical discharge. Furthermore, in order to perform stable EDM, a zero-point reset (zero-point correction) operation is performed at the start of EDM, involving contact between the wire guide tip and the workpiece to accurately measure the distance between the workpiece and the wire guide. Therefore, the second cylinder at the tip of the wire guide tends to wear down easily due to exposure to high-voltage electrical discharge or repeated physical contact with the workpiece.

[0006] Furthermore, during electrical discharge machining, foreign matter such as metal shavings and scraps may be scattered from the workpiece. This scattered foreign matter may adhere to the tip of the wire guide, etc. As a result, the smooth feeding of the wire from the wire guide may be hindered, leading to abnormal discharges and potentially preventing stable electrical discharge machining.

[0007] Therefore, the present disclosure aims to provide a wire guide and a wire electrode including the wire guide that suppress wear of the wire guide used in electrical discharge machining using an electrical discharge machine, and reduce the adhesion of foreign matter such as metal shavings, thereby suppressing the occurrence of abnormal discharges and enabling stable electrical discharge machining. [Means for solving the problem]

[0008] (1) One embodiment of the wire guide relating to this disclosure is: A first cylindrical body having a first end, a second end located at the other end of the first end, and a first through hole provided from the first end to the second end, The device comprises a third end, a fourth end located at the other end of the third end, and a second cylindrical body having a second through-hole extending from the third end to the fourth end and located inside the first through-hole at the second end, which overlaps with the first through-hole in a plan view from the first end side. The second cylinder is In the longitudinal direction extending from the first end to the second end, the fourth end is recessed toward the first end from the second end.

[0009] (2) One embodiment of the wire guide relating to this disclosure is The wire guide described in (1) above, The first through hole is It further has a first stepped portion that is tapered in diameter from the second end towards the first end, and has a stepped shape. The second cylinder is It is located between the first stepped portion and the second end portion.

[0010] (3) One embodiment of the wire guide relating to this disclosure is The wire guide described in (2) above, The third end is, It further has a first enlarged diameter portion opposite to the first stepped portion, in which the second through hole is tapered in diameter toward the first stepped portion, The diameter of the first enlarged portion hole of the first enlarged portion is It is larger than the first through-hole, which is reduced in diameter from the first stepped portion toward the first end.

[0011] (4) One embodiment of the wire guide relating to this disclosure is The wire guide described in (2) or (3) above, A first gap is further provided between the first stepped portion and the third end portion.

[0012] (5) One embodiment of the wire guide relating to this disclosure is A wire guide of any of the above (2) to (4), The first cylinder is A first press-fit portion is provided in the first through-hole extending from the first stepped portion to the second end, and has a first press-fit portion that is smaller than the diameter of the first hole at the second end. The second cylinder is The third end is press-fitted into the first press-fit portion and held in the first cylindrical body.

[0013] (6) One embodiment of the wire guide according to the present disclosure is, the wire guide according to any one of the above (1) to (5), further comprising a third cylindrical body having a fifth end portion, a sixth end portion located at the other end of the fifth end portion, and a third through-hole provided from the fifth end portion to the sixth end portion, the first cylindrical body is, press-fitting the first end portion into the third through-hole from the sixth end portion, and held by the third cylindrical body.

[0014] (7) One embodiment of the wire guide according to the present disclosure is, the wire guide according to the above (6), the first outer diameter of the first cylindrical body is, further having a second stepped portion that increases in diameter between the second end portion and the first end portion to form a stepped shape, the second stepped portion is, inserted through the third through-hole.

[0015] (8) One embodiment of the wire guide according to the present disclosure is, the wire guide according to the above (7), in the longitudinal direction extending from the fifth end portion to the sixth end portion, the second stepped portion is positioned recessed from the sixth end portion toward the fifth end portion side.

[0016] (9) One embodiment of the wire guide according to the present disclosure is, the wire guide according to any one of the above (6) to (8), the third through-hole is, further having a third stepped portion that reduces in diameter while extending from the sixth end portion toward the fifth end portion to form a stepped shape, the first end portion is, facing the third stepped portion, and further having a second enlarged diameter portion in which the first through-hole is enlarged in diameter in a tapered shape toward the third stepped portion, the hole diameter of the second enlarged diameter portion is, larger than the third through-hole that is reduced in diameter from the third stepped portion toward the fifth end portion.

[0017] (10) One embodiment of the wire guide relating to this disclosure is The wire guide described in (9) above, A second gap is further provided between the third stepped portion and the first end portion.

[0018] (11) One embodiment of the wire guide relating to this disclosure is The wire guides described in (9) or (10) above, The third cylinder is A second press-fit portion is provided in the third through-hole extending from the third stepped portion to the sixth end, and has a diameter smaller than the third hole diameter at the sixth end. The first cylinder is The first end is pressed into the second press-fit portion from the sixth end and held in the third cylindrical body.

[0019] (12) One embodiment of the wire guide relating to this disclosure is A wire guide of any of the above (6) to (11), The first cylinder and the third cylinder are Metal materials are used, The second cylinder is Ceramic materials are used.

[0020] (13) One embodiment of the wire guide relating to this disclosure is A wire guide of any of the above (1) to (12), The material of the second cylindrical body is Contains zirconium dioxide.

[0021] (14) One embodiment of the wire guide relating to this disclosure is A wire guide of any of the above (1) to (13), In a plan view from the second end side, the second through hole has an uneven shape with concave and convex portions on its inner circumference. The aforementioned recess is It extends along the longitudinal direction of the second through hole.

[0022] (15) One embodiment of the wire electrode relating to the present disclosure is A wire guide from any of the above (1) to (14), From the first end to the second end of the wire guide, the wire inserted through the first through hole and the second through hole, It is equipped with. [Effects of the Invention]

[0023] The wire guide and wire electrode of this disclosure are used in electrical discharge machining by an electrical discharge machine, and suppress wear of the tip of the wire guide, reduce the adhesion of foreign matter such as metal shavings, and enable stable electrical discharge machining of the workpiece. [Brief explanation of the drawing]

[0024] [Figure 1] This is a front view showing the schematic configuration of the wire guide and wire electrode of this embodiment. [Figure 2] This is an exploded perspective view showing the schematic configuration of the wire guide and wire electrode in this embodiment. [Figure 3] This is a cross-sectional view taken along line A-A' in Figure 1, showing the schematic configuration of the wire guide and wire electrode. [Figure 4] This is an enlarged cross-sectional view of the dashed circle region B in Figure 3, which shows the schematic configuration of the wire guide and wire electrode. [Figure 5] This is an enlarged cross-sectional view of area C in the dashed circle region of Figure 3, which shows the schematic configuration of the wire guide and wire electrode. [Figure 6] This is an enlarged cross-sectional view of the dashed circle region D in Figure 3, which shows the schematic configuration of the wire guide and wire electrode. [Figure 7] This is a bottom view showing the inner circumferential shape of the second through-hole of the second cylindrical body of the wire guide and wire electrode in an alternative configuration of the present disclosure. [Modes for carrying out the invention]

[0025] Embodiments of the present disclosure will be described below with reference to the drawings. However, for the sake of clarity, the drawings below are simplified to show only the main components necessary to describe the embodiments. Therefore, embodiments of the present disclosure may include any components not shown in the drawings. Furthermore, the drawings do not necessarily accurately represent the dimensional ratios of the actual components.

[0026] In this disclosure, the directions do not refer to the directions in actual use. Furthermore, for convenience, each direction is expressed using the Cartesian coordinate system XYZ, where the top is the positive side of the Z direction. In this disclosure, "plan view" means a view from above (the positive side of the Z direction), and includes planar perspective. Similarly, in this disclosure, "bottom view" means a view from below (the negative side of the Z direction), "front view" means a view from the positive side of the Y direction, "back view" means a view from the positive side of the Y direction, and "side view" means a view from the positive (or negative) side of the X direction.

[0027] Furthermore, expressions such as "constant," "orthogonal," "perpendicular," "parallel," and "same" may be used in the following descriptions. These expressions do not necessarily strictly mean "constant," "orthogonal," "perpendicular," "parallel," or "same," respectively, and may allow for deviations such as manufacturing accuracy or installation accuracy. Numerical ranges indicated using "~" include the values ​​before and after it as the lower and upper limits, respectively.

[0028] 1. [Wire guide and wire electrode] The wire guide 10 of this embodiment mainly comprises a first cylindrical body 20 and a second cylindrical body 30, as shown in Figures 1 to 6. The wire electrode 100 of this embodiment mainly comprises a wire guide 10 and a wire 101 inserted through the wire guide, as shown in Figure 1. In Figures 2-6 and Figure 7, which shows a wire guide 10a and wire electrode 100a of an alternative configuration, the wire 101 is represented by a dashed line for simplification of the illustration. Furthermore, Figures 4-6 are enlarged cross-sectional views obtained by enlarging the dashed circular regions B, C, and D in Figure 3, respectively.

[0029] In the wire guide 10 of this embodiment, the first cylindrical body 20 has a first end 21, a second end 22 located at the other end of the first end 21, and a first through hole 40 provided from the first end 21 to the second end 22.

[0030] The second cylindrical body 30 has a third end 31, a fourth end 32 located at the other end of the third end 31, and a second through hole 41 extending from the third end 31 to the fourth end 32, located inside the first through hole 40 in the second end 22, and overlapping with the first through hole 40 in a plan view from the first end 21 side.

[0031] In the longitudinal direction of the second cylindrical body 30, extending from the first end 21 to the second end 22 (the direction from the top to the bottom of the paper in Figure 1), the fourth end 32 is recessed toward the first end 21 from the second end 22.

[0032] As shown in Figures 1, 3, and 4, in the wire guide 10 of this embodiment, the second cylindrical body 30 is inserted into the first through-hole 40 from the second end 22 side of one end (the lower end in Figure 1) of the first cylindrical body 20, and the entire second cylindrical body 30 is held in a fitted state. Therefore, in a front view from the positive side in the Y direction of Figure 1, the second cylindrical body 30, which is housed and held inside the first cylindrical body 20, is not visible. The first through-hole 40 of the first cylindrical body 20 and the second through-hole 41 of the second cylindrical body 30 are in communication with each other inside the wire guide 10.

[0033] The wire 101 is a component composed of linear electrode wires. The wire 101 is led out from the first end 21 of the first cylindrical body 20, through the first through hole 40 and the second through hole 41, through the fourth end 32 of the second cylindrical body 30, and to the second end 22 of the first cylindrical body 20. As a result, the wire 101 is set in the wire guide 10, becoming the wire electrode 100 of this embodiment. The first cylindrical body 20 may be held in place by at least a portion of the third cylindrical body 50, which will be described later.

[0034] In this disclosure, the wire 101 used in the wire guide 10 and wire electrode 100 is not particularly limited, and the material, wire diameter, etc. may be appropriately selected depending on the workpiece to be machined and the machining accuracy required for electrical discharge machining.

[0035] For example, the wire 101 may be made of brass, copper, copper-tungsten, or graphite. Similarly, the wire diameter (thickness) of the wire 101 can be appropriately selected according to the processing accuracy, etc., and for example, wires in the range of 0.3 mm to 5 mm can be used. The first through hole 40 of the first cylindrical body 20 and the second through hole 41 of the second cylindrical body 30 of the wire guide 10 are selected to have an inner diameter that allows for smooth insertion and delivery of the wire 101.

[0036] In performing electrical discharge machining using an electrical discharge machine, first, the wire electrode 100 of this embodiment, with the wire 101 set in the wire guide 10, is attached to the electrical discharge machine. Then, a predetermined voltage is applied. Here, in electrical discharge machining using an electrical discharge machine, the wire 101 inserted inside the wire guide 10 is rotated within the holes of the first through hole 40 and the second through hole 41 with the insertion direction (feeding direction, corresponding to the longitudinal direction of the wire guide 10, corresponding to the vertical direction of the paper in Figure 1) as the axis of rotation. While rotating the wire 101, the wire 101 extending from the second end 22 is brought closer to the workpiece to be machined. As a result, a discharge phenomenon occurs between the wire 101 and the workpiece, and electrical discharge machining of the workpiece, such as cutting out the desired shape, is performed by this discharge.

[0037] The first cylindrical body 20, which is one component of the wire guide 10 in this embodiment, is a longitudinal member with a substantially cylindrical shape (pipe-like), as shown in Figures 1 and 3, and has a first through-hole 40 that penetrates from the first end 21 to the second end 22. The dimensions of the first cylindrical body 20 are not particularly limited, and for example, the first cylindrical body length L1, which corresponds to the longitudinal length of the first cylindrical body 20, may be in the range of 100 mm to 400 mm, the first outer diameters D1 and D1a, which correspond to the outer diameter of the cylindrical body of the first cylindrical body 20, may be in the range of 2 mm to 15 mm, and the first hole diameters P1 and P1a, which correspond to the inner diameter of the first through-hole 40 of the first cylindrical body 20, may be in the range of 0.5 mm to 10 mm. Details of the first outer diameters D1 and D1a and the first hole diameters P1 and P1a will be described later.

[0038] The materials used to construct the first cylindrical body 20 are not particularly limited, and metal materials such as brass, cemented carbide, high-speed steel, and stainless steel (SUS) can generally be used. Using metal materials improves the machinability of the roughly cylindrical first cylindrical body 20.

[0039] The second cylindrical body 30, which is a component of the wire guide 10, is a longitudinally shaped member with a substantially cylindrical (pipe-like) form, as shown in Figures 1, 3, and 4, etc. It is fitted into the first through hole 40 from the second end 22 side of the first cylindrical body 20 and is held by the first cylindrical body 20. The dimensions of the second cylindrical body 30 are not particularly limited, and it is sufficient as long as it can be fitted into the second end 22 side of the first cylindrical body 20 as described above.

[0040] For example, the second cylindrical length L2, which corresponds to the length of the second cylindrical body 30, may be 5 mm to 30 mm, the second outer diameter D2, which corresponds to the outer diameter of the second cylindrical body 30, may be 0.5 mm to 5 mm, and the second hole diameter P2, which corresponds to the inner diameter of the second through hole 41 of the second cylindrical body 30, may be in the range of 0.3 mm to 3 mm. In addition, the second hole diameter P2 of the second through hole 41 of the second cylindrical body 30 may be the same as or smaller than the first hole diameter P1 of the first through hole 40 on the first end 21 side of the first cylindrical body 20 (P1 ≥ P2). This makes it easier to insert the wire 101 between the first cylindrical body 20 and the second cylindrical body 30.

[0041] The material of the second cylinder 30 is not particularly limited, and for example, ceramic materials with excellent insulating properties, heat resistance, and wear resistance can generally be used. In particular, among ceramic materials, the use of alumina or zirconia (zirconium dioxide), which have excellent strength and high wear resistance against high-voltage discharge, is preferred. Alternatively, silicon carbide or silicon nitride, which have excellent thermal conductivity and heat resistance, may be used. Furthermore, ruby ​​or cemented carbide, which have aluminum oxide (alumina) as the main component, may also be used. The purity of the ceramic material such as alumina or zirconia used in the second cylinder 30 is not particularly limited, and for example, a purity of 99% or higher may be used, and it is acceptable even if it contains some impurities.

[0042] In the wire guide 10 of this embodiment, the second cylindrical body 30 has a fourth end 32 that is recessed toward the first end 21 side from the second end 22 in the longitudinal direction extending from the first end 21 to the second end 22 of the first cylindrical body 20. That is, the second end 22 of the first cylindrical body 20 and the fourth end 32 of the second cylindrical body 30 are not arranged flush in a front view, but rather the fourth end 32 is located in the hole of the first through hole 40 that is recessed toward the first end 21 side from the second end 22. In other words, as shown in Figure 4, the fourth end 32 of the second cylindrical body 30 is located toward the first end 21 side from the second end 22 (above the plane of the paper in Figure 4) relative to the second end 22 of the first cylindrical body 20. As a result, in the front view shown in Figure 1, the fourth end 32 of the second cylindrical body 30 does not protrude from the second end 22, and the second cylindrical body 30 cannot be seen.

[0043] The fourth end 32 of the second cylinder 30 is positioned recessed from the second end 22 of the first cylinder 20. This reduces the possibility of foreign matter such as metal shavings generated during electrical discharge machining colliding with and adhering to the fourth end 32 of the second cylinder 30. As a result, the possibility of wear on the fourth end 32 (second cylinder 30) due to collision with foreign matter such as metal shavings is reduced.

[0044] Furthermore, during the zero-point correction (zero-point reset) performed at the start of electrical discharge machining, the second cylinder 30 is recessed compared to the second end 22 of the first cylinder 20, thus protecting the second cylinder 30 from the first cylinder 20. As a result, physical contact between the workpiece being machined and the second cylinder 30 is limited. Consequently, the possibility of wear on the second cylinder 30 is further reduced.

[0045] As described above, in this embodiment, the wire guide 10 is positioned such that the fourth end 32 of the second cylindrical body 30 is recessed toward the first end 21 relative to the second end 22 of the first cylindrical body 20. This reduces the possibility of metal debris and other foreign matter adhering to the wire guide, as well as the possibility of physical contact with the workpiece. This suppresses the possibility of wear of the second cylindrical body 30. Furthermore, by reducing the adhesion of foreign matter such as metal debris, the occurrence of abnormal discharges is suppressed, enabling stable electrical discharge machining by the electrical discharge machine.

[0046] The first recess amount (see Figure 4) relating to the fourth end 32, which corresponds to the distance between the second end 22 and the fourth end 32, is not particularly limited and can be in the range of, for example, 0.05 mm to 0.5 mm. By setting the above first recess amount H1 to 0.05 mm or more, the above-mentioned effects can be enjoyed, and the wear of the second cylindrical body 30 can be reduced.

[0047] On the other hand, if the first recess amount H1 exceeds 0.5 mm, the wire guide 10 may not be able to adequately guide the wire 101 at its tip, causing slack and making it difficult to stably hold the wire 101 in a straight position. Therefore, by specifying the first recess amount H1 to 0.5 mm or less as described above, the original wire guide 10's support function for the wire 101 is not impaired. As a result, electrical discharge machining of the workpiece can be performed stably.

[0048] In the wire guide 10 of this embodiment, the first through hole 40 may further have a first stepped portion 23 that is tapered in diameter between the second end portion 22 and the first end portion 21. The second cylindrical body 30 is located between the first stepped portion 23 and the second end portion 22.

[0049] In this disclosure, the area from the second end 22 toward the first end 21 corresponds to the direction from the bottom of the paper toward the top of the paper in Figures 1, 3, and 4. As shown in Figure 4, the first hole diameter P1 (hereinafter referred to as "the first hole diameter P1 on the first end 21 side") corresponding to the inner diameter of the first through hole 40 between the first step portion 23 and the second end 21 is smaller than the first hole diameter P1a (hereinafter referred to as "the first hole diameter P1 on the second end 22 side") corresponding to the inner diameter of the first through hole 40 between the second end 22 and the first step portion 23. In other words, the first hole diameter P1a on the second end 22 side is larger than the first hole diameter P1 on the first end 21 side. That is, in the wire guide 10 of this embodiment, the hole diameter of the first through hole 40 provided inside the first cylindrical body 20 changes between the first end 21 and the second end 22 with the first step portion 23 as the boundary.

[0050] As shown in Figure 4, the first hole diameter P1 on the first end 21 side is smaller than the second outer diameter D2 of the second cylindrical body 30 fitted into the first through hole 40 from the second end 22 side. Therefore, when the second cylindrical body 30 is inserted into the first through hole 40 from the second end 22 side, the third end 31 comes into contact with the first stepped portion 23, and further movement toward the first end 21 side (upward side of the paper in Figure 4) is restricted. This limits the excessive insertion of the second cylindrical body 30 into the hole of the first through hole 40. Consequently, the second cylindrical body 30 is fitted into and held within the first recess amount H1 between the second end 22 and the fourth end 32, which is predetermined. This stabilizes the support of the wire 101 by the wire guide 10.

[0051] In the wire guide 10 of this embodiment, the third end 31 of the second cylindrical body 30 faces the first end 21 of the first cylindrical body 20 and further has a first enlarged diameter portion 33 in which the second through hole 41 tapers toward the first stepped portion 23. The diameter E1 of the first enlarged diameter portion 33 is larger than the first diameter P1 of the first through hole 40 between the first stepped portion 23 and the first end 21 (see Figure 4).

[0052] The third end 31 of the second cylindrical body 30 has a first enlarged diameter portion 33 that is tapered in diameter, which prevents the second cylindrical body 30 from obstructing the insertion of the wire 101 from the first end 21 to the second end 22.

[0053] More specifically, the tip of the wire 101, which is inserted through the first through-hole 40 having a first hole diameter P1 on the first end 21 side, passes over the first stepped portion 23 and reaches the third end 31 of the second cylindrical body 30. In the first enlarged diameter portion 33 provided at the third end 31 of the second cylindrical body 30, the second through-hole 41 enlarges toward the first stepped portion 23 and opens with a first enlarged diameter portion hole diameter E1, which is larger than the first hole diameter P1 on the first end 21 side. Furthermore, as one moves from the third end 31 toward the fourth end 32, the hole diameter decreases from the first enlarged diameter portion hole diameter E1 to a second hole diameter P2, which is smaller than the first hole diameter P1 in a plan view.

[0054] Therefore, the tip of the wire 101, which is fed out from the first end 21 and reaches the first enlarged diameter section 33 after passing through the first through hole 40 with a first hole diameter P1, is further fed out toward the first enlarged diameter section 33, where the hole diameter gradually narrows in the insertion direction (downward direction in Figure 4). As a result, the tip of the wire 101 can smoothly advance through the second through hole 41 of the second cylindrical body 30 without being obstructed between the first stepped section 23 of the first cylindrical body 20 and the first enlarged diameter section 33 of the second cylindrical body 30.

[0055] In other words, the first enlarged diameter portion 33 provided in the second cylindrical body 30 facilitates the feeding of the wire 101 toward the second end portion 22. This makes it easier to set the wire 101 into the wire guide 10 and further enables smooth feeding of the wire 101 during electrical discharge machining.

[0056] The difference in hole diameter between the first hole diameter P1 on the first end 21 side and the first enlarged hole diameter E1 of the first enlarged portion 33 is not particularly limited. For example, it is possible to make the first enlarged hole diameter E1 larger than the first hole diameter P1 on the first end 21 side by a difference in hole diameter in the range of 0.05 mm to 0.30 mm. By making the first enlarged hole diameter E1 of the second through hole 41 opening toward the first enlarged portion 33 0.05 mm or more larger than the first hole diameter P1 of the first through hole 40, the smooth feeding of the wire 101 as described above becomes possible. On the other hand, by making the difference in hole diameter 0.30 mm or less, the possibility of the size of the second cylindrical body 30 becoming larger is reduced.

[0057] In the wire guide 10 of this embodiment, a first gap 24 may be further provided between the first stepped portion 23, which is located within the first through-hole 40 of the first cylindrical body 20 described above, and the third end portion 31 of the second cylindrical body 30.

[0058] In other words, the second cylindrical body 30 may be held in the first cylindrical body 20 in a state where the third end 31 of the second cylindrical body 30 does not come into contact with the first stepped portion 23. This allows for tolerance of manufacturing tolerances in the first through hole 40, the first stepped portion 23, and the second cylindrical body 30 in the first cylindrical body 20. As a result, when the second cylindrical body 30 is fitted and held in the first cylindrical body 20, the fourth end 32 of the second cylindrical body 30 does not protrude from the second end 22 of the first cylindrical body 20, and the fourth end 32 can be stably positioned in a recessed position relative to the second end 22.

[0059] In the wire guide 10 of this embodiment, the first cylindrical body 20 is provided in the first through hole 40 extending from the first stepped portion 23 to the second end portion 22, and has a first press-fit portion 25 with a hole diameter smaller than the first hole diameter P1a of the second end portion 22. The second cylindrical body 30 is held by the first cylindrical body 20 by press-fitting its third end portion 31 into the first press-fit portion 25.

[0060] In other words, in the first through hole 40 into which the second cylindrical body 30 is inserted, a first press-fit portion 25 is provided near the first stepped portion 23, with a hole diameter slightly smaller than the first hole diameter P1a on the second end portion 22 side. As a result, when the second cylindrical body 30 is inserted into the first through hole 40 of the first cylindrical body 20, the third end portion 31 of the second cylindrical body 30 comes into contact with the first press-fit portion 25 before reaching the first stepped portion 23. Furthermore, by pushing the second cylindrical body 30 toward the first stepped portion 23, the area near the third end portion 31 of the second cylindrical body 30 is crimped by the first press-fit portion 25. As a result, the second cylindrical body 30 is firmly held in place by the first cylindrical body 20.

[0061] The first hole diameter in the first press-fit portion 25 is not particularly limited, and for example, it should have a hole diameter difference of about 0.03 mm to 0.30 mm with respect to the first hole diameter P1a on the second end portion 22 side. By setting it within this range, it becomes possible to firmly and stably hold the second cylindrical body 30 in the first cylindrical body 20. The first press-fit portion 25 may be formed in a part of the section extending from the first stepped portion 23 toward the second end portion 22. The length of the first press-fit portion 25 is not particularly limited, and for example, it should be about 5 to 30% of the second cylindrical body length L2 of the second cylindrical body 30 inserted into the first through hole 40. By setting it to 5% or more of the second cylindrical body length L2, it becomes possible for the first cylindrical body 10 to stably hold the second cylindrical body 30 and to suppress the tilting of the second cylindrical body 30 relative to the first through hole 40. On the other hand, by making the length of the second cylinder L2 30 less than 30%, it becomes possible to reduce the difficulty in press-fitting the second cylinder 30 into the first through hole 40. Also, although Figure 4 and other figures show a case where the first hole diameter P1a on the second end 22 side and the second outer diameter D2 of the second cylinder 30 coincide, the case is not limited to this, and there may be a gap between the first hole diameter P1a and the second outer diameter D2. This makes it easier to insert the second cylinder 30 into the first cylinder 20.

[0062] The wire guide 10 of this embodiment may further include a third cylindrical body 50, as shown in Figure 1, etc. The third cylindrical body 50 has a fifth end 51, a sixth end 52 located at the other end of the fifth end 51, and a third through hole 42 provided from the fifth end 51 to the sixth end 52. The first cylindrical body 20 is held in the third cylindrical body 50 by inserting the first end 21 from the sixth end 52 into the third through hole 42 and press-fitting it.

[0063] As shown in Figure 1, the third cylindrical body 50 constituting the wire guide 10 is substantially cylindrical in shape, and the first end 21 side of the first cylindrical body 20 is fitted into and held in the third through hole 42. The dimensions of the third cylindrical body 50 are not particularly limited; for example, the length L3 of the third cylindrical body may be in the range of 30 mm to 200 mm, the third outer diameter D3 corresponding to the outer diameter of the third cylindrical body 50 may be in the range of 5 mm to 50 mm, and the third hole diameter P3 corresponding to the inner diameter of the third through hole 42 of the third cylindrical body 50 may be in the range of 2 mm to 15 mm.

[0064] In the wire guide 10, if the length L1 of the first cylindrical body 20 exceeds, for example, 400 mm, it becomes difficult to integrally form the first cylindrical body 20, which may reduce the dimensional accuracy of the wire guide 10. Therefore, in the wire guide 10 of this embodiment, by configuring the first cylindrical body 20 and the third cylindrical body 50 as separate components, it is possible to increase the overall length L of the wire guide 10 and improve the dimensional accuracy of the wire guide 10.

[0065] This increases the design flexibility of the wire guide 10 that is set in the electrical discharge machining machine. Furthermore, the third cylinder 50 (or the first cylinder 20) may be provided with a flange portion 53 or the like protruding from the outer surface of the cylinder, as shown in Figure 1, etc. This facilitates gripping the wire guide 10 by the electrical discharge machining machine.

[0066] The third cylindrical body 50 constituting the wire guide 10 is a longitudinally shaped member with a substantially cylindrical (pipe-like) form, as shown in Figures 1, 3, and 6, and only needs to be able to be fitted into the third through hole 42 and held by the third cylindrical body 50. The dimensions of the third cylindrical body 50 are not particularly limited, and only needs to be able to be fitted into at least a portion of the first end 21 side of the first cylindrical body 20 as described above.

[0067] The materials used to construct the third cylinder 50 are not particularly limited. For example, similar to the first cylinder 20, metal materials such as brass, cemented carbide, high-speed steel, and stainless steel (SUS) can generally be used. Using metal materials improves the machinability of the substantially cylindrical third cylinder 50. In addition, the first cylinder 20 and the third cylinder 50 may be formed using the same material, or they may be made of different materials. By forming the first cylinder 20 and the third cylinder 50 from the same material, it is possible to reduce the manufacturing cost of the wire guide 10.

[0068] In the wire guide 10 of this embodiment, if the configuration relating to the third cylindrical body 50 is included, the total length L of the wire guide 10 may be in the range of, for example, 150 mm to 500 mm (see Figure 3). Also, in the first cylindrical body 20, which is partially inserted into and held in the third through hole 42 of the third cylindrical body 50, the overlapping length L4 where the first cylindrical body 20 and the third cylindrical body 50 overlap may be in the range of, for example, 30 mm to 150 mm, and the protruding length L5 of the first cylindrical body 20 protruding from the third cylindrical body 50 may be in the range of, for example, 70 to 300 mm. Note that the first hole diameter P1 of the first through hole 40 on the first end 21 side of the first cylindrical body 20 may be the same as or smaller than the third hole diameter P3a of the third through hole 42 on the fifth end 51 side of the third cylindrical body 50 (P3a ≥ P1). This makes it easier to insert the wire 101 between the third cylinder 50 and the first cylinder 20.

[0069] Furthermore, in the wire guide 10 of this embodiment, the first cylindrical body 20 may further have a second stepped portion 26 which expands in diameter between the second end 22 and the first end 21 (for example, between the direction from the bottom of the paper to the top of the paper in Figures 3 and 5), resulting in a stepped shape. The second stepped portion 26 is inserted through the third through hole 42.

[0070] If the first outer diameter D1 of the first cylindrical body 20 is small, there is a possibility that the first cylindrical body 20 may deform when inserted into the third through hole 42 of the third cylindrical body 50. For this reason, the first cylindrical body 20 inserted into the third through hole 42 may have a first outer diameter D1a that is wider between the second step portion 26 and the first end portion 21 than the first outer diameter between the second end portion 22 and the second step portion 26. The first outer diameter D1a of the first cylindrical body 20 is formed to be within a range that allows insertion into the third hole diameter P3, which corresponds to the inner diameter of the third through hole 42 of the third cylindrical body 50. This reduces the possibility of the first cylindrical body 20 deforming when inserted into the third through hole 42 of the third cylindrical body 50.

[0071] In the wire guide 10 of this embodiment, the first cylindrical body 20 may have the second stepped portion 26 recessed from the sixth end 52 towards the fifth end 51 in the longitudinal direction (corresponding to the direction from the top of the paper to the bottom of the paper in Figures 1 and 5) extending from the fifth end 51 to the sixth end 52 of the third cylindrical body 50.

[0072] By having this configuration, the possibility of the first cylindrical body 20 being press-fitted into the third cylindrical body 50 with the enlarged second stepped portion 26 of the first cylindrical body 20 protruding from the sixth end portion 52 of the third cylindrical body 50 is reduced. As a result, the possibility of the protruding second stepped portion 26 coming into contact with surrounding equipment or the workpiece being processed is reduced. The second recess amount H2 (see Figure 5) between the second stepped portion 26 and the sixth end portion 52 of the third cylindrical body 50 is not particularly limited, but can be in the range of 0.3 mm to 2.0 mm, for example. By setting the second recess amount H2 to 2.0 mm or less, it becomes possible to stably hold the first cylindrical body 20 in the third cylindrical body 50.

[0073] In the wire guide 10 of this embodiment, the third through hole 42 may further have a third stepped portion 54 that is tapered in diameter from the sixth end 52 to the fifth end 51. The first end 21 of the first cylindrical body 20 has a second enlarged diameter portion 27 that faces the third stepped portion 54 and is tapered in diameter toward the third stepped portion. The second enlarged diameter hole diameter E2 of the second enlarged diameter portion 27 may be the same as, or larger than, the third hole diameter P3a of the third through hole 42 toward the fifth end 51 from the third stepped portion 54.

[0074] In this disclosure, the area from the sixth end 52 to the fifth end 51 corresponds to the direction from the bottom of the paper to the top of the paper in Figures 1, 3, 5, and 6. As shown in Figures 3, 5, and 6, the third hole diameter P3a (hereinafter referred to as "the third hole diameter P3a on the fifth end 51 side"), which corresponds to the inner diameter of the third through hole 42 between the third step portion 54 and the fifth end 51, is smaller than the third hole diameter P3 (hereinafter referred to as "the third hole diameter P3 on the sixth end 52 side"), which corresponds to the inner diameter of the third through hole 42 between the sixth end 52 and the third step portion 54. In other words, the third hole diameter P3 on the sixth end 52 side is larger than the third hole diameter P3a on the fifth end 51 side. In other words, in the wire guide 10 of this embodiment, the third through hole 42 provided inside the third cylindrical body 50 has a hole diameter that changes between the fifth end portion 51 and the sixth end portion 52, with the third stepped portion 54 as the boundary.

[0075] As shown in Figure 6, the diameter P3a of the third hole on the fifth end 51 side is smaller than the first outer diameter D1a of the first cylindrical body 20 fitted into the third through hole 42 from the sixth end 52 side. Therefore, when the first end 11 of the first cylindrical body 20 comes into contact with the third stepped portion 54, further movement toward the fifth end 51 side (upward side of the paper in Figure 6) is restricted. This prevents the first cylindrical body 20 from being inserted too far into the hole of the third through hole 42. As a result, the second recess amount H2 between the sixth end 52 and the second stepped portion 26 can be kept within a predetermined range, making it possible to stably hold the wire 101.

[0076] The first end 21 of the first cylindrical body 20 has a second enlarged diameter portion 27 that is tapered in diameter, which facilitates the insertion of the wire 101 from the fifth end 51 of the third cylindrical body 50 towards the second end 22 of the first cylindrical body 20 between the third through hole 42 and the first through hole 40. The tip of the wire 101, which is inserted through the third through hole 42 having a third hole diameter P3a on the fifth end 51 side, passes over the third stepped portion 54 and reaches the first end 21 of the first cylindrical body 20. In the second enlarged diameter portion 27 provided at the first end 21 of the first cylindrical body 20, the first through hole 40 enlarges toward the third stepped portion 54 and opens with a second enlarged diameter portion hole diameter E2, which is larger than the third hole diameter P3a on the fifth end 51 side. Furthermore, as one moves from the first end 21 toward the second end 22, the second enlarged diameter portion hole diameter E2 decreases, and the hole diameter changes to a first hole diameter P1, which is smaller than the third hole diameter P3a in a plan view.

[0077] The tip of the wire 101, which is fed out from the fifth end 51 and reaches the second enlarged diameter section 27 after passing through the third through hole 42 with a third hole diameter P3a, is further fed along the second enlarged diameter section 27, where the hole diameter gradually narrows in the insertion direction (downward direction in Figure 6). As a result, the tip of the wire 101 can move smoothly through the first through hole 40 of the first cylindrical body 20 without getting caught. In other words, the second enlarged diameter section 27 provided at the first end 21 of the first cylindrical body 20 facilitates the feeding of the wire 101 toward the second end 22 and the second cylindrical body 30. This facilitates the feeding of the wire 101 inserted between the fifth end 51 and the second end 22 during electrical discharge machining, and the setting of the wire 101 into the wire guide 10. Furthermore, the third through hole 42 opening at the fifth end 51 of the third cylindrical body 50 may have a third enlarged diameter section that gradually expands in diameter from the third stepped portion 54 side toward the fifth end 51, and opens with a third enlarged diameter section hole diameter that is larger than the third hole diameter P3a on the third stepped portion 54 side. This makes it even easier to set the wire 101 into the wire guide 10. Also, the third enlarged diameter section hole diameter of the third enlarged diameter section may be larger than the second enlarged diameter section hole diameter E2 of the second enlarged diameter section 27 opening at the first end 21 of the first cylindrical body 20.

[0078] Here, the difference in hole diameter between the third hole diameter P3a on the fifth end portion 51 side and the second enlarged hole diameter E2 of the second enlarged portion 27 is not particularly limited. For example, the second enlarged hole diameter E2 can be made larger than the third hole diameter P3a on the fifth end portion 51 side by a difference in hole diameter in the range of 0.05 mm to 0.30 mm. By making the second enlarged hole diameter E2 of the first through hole 40 opening toward the second enlarged portion 27 0.05 mm or more larger than the third hole diameter P3a of the third through hole 42, the smooth feeding of the wire 101 as described above becomes possible. On the other hand, by making the difference in hole diameter 0.30 mm or less, the possibility of the size of the first cylindrical body 20 becoming larger is reduced.

[0079] In the wire guide 10 of this embodiment, there may be a second gap 28 between the third stepped portion 54 provided in the third through hole 42 of the third cylindrical body 50 and the first end portion 21 of the first cylindrical body 20.

[0080] In other words, the first cylindrical body 20 may be held in the third cylindrical body 50 in a state where the first end 21 of the first cylindrical body 20 does not come into contact with the third stepped portion 54. This allows for tolerance of manufacturing tolerances in the third through hole 42 and the third stepped portion 54 in the third cylindrical body 50 and the first cylindrical body 20. As a result, it becomes possible to set the overlapping length L4 of the first cylindrical body 20 and the third cylindrical body 50 within the range described above.

[0081] In the wire guide 10 of this embodiment, the third cylindrical body 50 is provided in the third through hole 42 extending from the third stepped portion 54 to the sixth end portion 52, and has a second press-fit portion 55 that is smaller than the third hole diameter P3 of the sixth end portion 52. The first cylindrical body 20 is press-fitted from the sixth end portion 52 to the first end portion 21 into the second press-fit portion 55 and held by the third cylindrical body 50.

[0082] In other words, in the third through hole 42 of the third cylindrical body 50 into which the first cylindrical body 20 is inserted, a second press-fit portion 55 is provided near the third stepped portion 54, with a hole diameter slightly smaller than the third hole diameter P3. As a result, when the first cylindrical body 20 is inserted into the third cylindrical body 50 from the first end 21 side and pushed in, the outer surface of the cylindrical body near the first end 21 of the first cylindrical body 20 comes into contact with the second press-fit portion 55, and a part of the first cylindrical body 20 is pressed into the second press-fit portion 55. As a result, the first cylindrical body 20 is stably held in the third cylindrical body 50.

[0083] The diameter of the first hole in the second press-fit portion 55 is not particularly limited, and for example, it should have a diameter difference of about 0.03 mm to 0.30 mm with respect to the third hole diameter P3 on the sixth end portion 52 side. By setting it within this range, it is possible to firmly and stably hold the first cylindrical body 20 in the third cylindrical body 50. The second press-fit portion 55 may be formed in a part of the third stepped portion 54 extending toward the sixth end portion 52. The length of the second press-fit portion 55 is not particularly limited, and for example, it should be about 5 to 30% of the first cylindrical body length L1 of the first cylindrical body 20 inserted into the third through hole 42. By setting it to 5% or more of the first cylindrical body length L1, it is possible for the third cylindrical body 50 to stably hold the first cylindrical body 10 and suppress the tilting of the first cylindrical body 10 relative to the third through hole 42. On the other hand, by making the length L1 of the first cylinder 30% or less, it becomes possible to reduce the difficulty in press-fitting the first cylinder 20 into the third through hole 42. Also, although Figure 6 and other figures show a case where the diameter P3 of the third hole on the sixth end 52 side and the first outer diameter D1a of the first cylinder 20 coincide, the case is not limited to this, and there may be a gap between the third hole diameter P3 and the first outer diameter D1a. This makes it easier to insert the first cylinder 20 into the third cylinder 50.

[0084] In the wire guide 10a of an alternative configuration of the present disclosure, as shown in Figure 7, in a plan view from the second end 22 side, in other words, a bottom view from the negative side in the Z direction, the second through hole 41a opening in the fourth end 32a has an uneven shape with a recess 70 and a protrusion 71 on its inner circumference, and the recess 70 may have a second cylindrical body 30a that extends along the longitudinal direction of the second through hole 41a (corresponding to the direction from the bottom to the top of the paper in Figure 1).

[0085] As a result, the outer surface of the wire 101 inserted into the second through-hole 41a comes into contact with the protrusion 71 in the second through-hole 41a, enabling stable holding of the wire 101. On the other hand, the recess 70 in the second through-hole 41a creates equally spaced gaps between the outer surface of the wire 101 and the second through-hole 41a. This reduces the occurrence of foreign matter such as metal shavings generated during electrical discharge machining getting stuck between the wire 101 and the second through-hole 41a, which would prevent the wire 101 from being fed out smoothly. This makes it possible to perform electrical discharge machining using the wire guide 10a stably.

[0086] Furthermore, details shown in the above embodiments may be modified as appropriate without departing from the spirit of this disclosure. The scope of the present invention includes the scope of the invention as described in the claims and its equivalents. Various combinations of each embodiment are not limited to the examples of embodiments described above. Combinations of each embodiment are also possible. [Explanation of Symbols]

[0087] 10,10a Wire Guide 20 First cylinder 21 First end 22 Second end 23 First step section 24 1st cavity 25 First press-fit section 26 Second step section 27 Second enlarged diameter section 28 Second cavity 30,30a 2nd cylinder 31 Third end 32,32a 4th end 33 1st enlarged diameter section 40 First through hole 41,41a 2nd through hole 42 Third through hole 50 Third cylinder 51 5th end 52 6th end 53 Flange section 54 Third step section 55 Second press-fit section 70 recess 71 Convex part 100,100a wire electrodes 101 Wire B Dashed circle region C Dashed circle region D Dashed circle region D1, D1a First outer diameter D2 2nd outer diameter D3 Third outer diameter E1 1st enlarged diameter part hole diameter E2 2nd enlarged diameter part hole diameter H1 First indentation amount H2 Second indentation amount L total length L1 First cylinder length L2 Second cylindrical length L3 Third cylinder length L4 Overlap Length L5 Projection length P1,P1a 1st hole diameter P2 2nd hole diameter P3,P3a 3rd hole diameter

Claims

1. A first cylindrical body having a first end, a second end located at the other end of the first end, and a first through hole provided from the first end to the second end, The device comprises a third end, a fourth end located at the other end of the third end, and a second cylindrical body having a second through-hole extending from the third end to the fourth end and located inside the first through-hole at the second end, which overlaps with the first through-hole in a plan view from the first end side. The second cylinder is A wire guide in which, in the longitudinal direction extending from the first end to the second end, the fourth end is recessed toward the first end from the second end.

2. The first through hole is, It further has a first stepped portion that is tapered in diameter from the second end towards the first end, and has a stepped shape. The second cylinder is The wire guide according to claim 1, located between the first stepped portion and the second end portion.

3. The third end is, It further has a first enlarged diameter portion facing the first stepped portion, in which the second through hole is tapered in diameter toward the first stepped portion, The diameter of the first enlarged portion hole of the first enlarged portion is The wire guide according to claim 2, which is larger than the first through-hole that is reduced in diameter from the first stepped portion toward the first end.

4. The wire guide according to claim 2, further comprising a first gap between the first stepped portion and the third end portion.

5. The first cylinder is A first press-fit portion is provided in the first through-hole extending from the first stepped portion to the second end, and has a first press-fit portion that is smaller than the diameter of the first hole at the second end. The second cylinder is The wire guide according to claim 2, wherein the third end is press-fitted into the first press-fit portion and held in the first cylindrical body.

6. The third cylindrical body further comprises a fifth end, a sixth end located at the other end of the fifth end, and a third through-hole provided from the fifth end to the sixth end. The first cylinder is The wire guide according to claim 1, wherein the first end is press-fitted into the third through-hole from the sixth end and held by the third cylindrical body.

7. The first outer diameter of the first cylindrical body is It further has a second stepped portion that widens in diameter between the second end and the first end, The second stepped portion is, The wire guide according to claim 6, which is inserted through the third through hole.

8. The first cylinder is The wire guide according to claim 7, wherein, in the longitudinal direction extending from the fifth end to the sixth end, the second stepped portion is recessed from the sixth end toward the fifth end.

9. The third through hole is, It further has a third stepped portion that is tapered in diameter from the sixth end to the fifth end, and has a stepped shape. The first end is, Opposite the third stepped portion, it further has a second enlarged diameter portion in which the first through hole is tapered in diameter toward the third stepped portion, The diameter of the second enlarged portion hole is The wire guide according to claim 6, which is larger than the third through-hole that is reduced in diameter from the third stepped portion toward the fifth end.

10. The wire guide according to claim 9, further comprising a second gap between the third stepped portion and the first end portion.

11. The third cylinder is A second press-fit portion is provided in the third through-hole extending from the third stepped portion to the sixth end, and has a diameter smaller than the third hole diameter at the sixth end. The first cylinder is The wire guide according to claim 9, wherein the first end is press-fitted into the second press-fit portion from the sixth end and held in the third cylindrical body.

12. The first cylinder and the third cylinder are Metal materials are used, The second cylinder is A wire guide according to claim 6, wherein a ceramic material is used.

13. The material of the second cylindrical body is A wire guide according to claim 1, comprising zirconium dioxide.

14. In a plan view from the second end side, the second through hole has an uneven shape with concave and convex portions on its inner circumference. The aforementioned recess is The wire guide according to claim 1, extending along the longitudinal direction of the second through hole.

15. A wire guide according to any one of claims 1 to 14, From the first end to the second end of the wire guide, the wire inserted through the first through hole and the second through hole, A wire electrode equipped with a wire electrode.

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