阅读说明：本技术 放电加工装置的放电加工单元 (electric discharge machining unit of electric discharge machining apparatus ) 是由 高桥润 藤泽泰彦 土肥祐三 于 2019-08-06 设计创作，主要内容包括：本发明提供一种具备工具电极、壳体、电极导向器、以及加工液供给装置的放电加工单元。具体的,工具电极插通到电极导向器中。壳体具备具有锥形面的嵌合孔,且在锥形面上设置有第1供给通路出口,在壳体内形成有连接加工液供给装置和第1供给通路出口的第1供给通路。电极导向器具备具有锥形状的锥形部和形成于下表面的喷射口,在锥形部的锥形面上设置有第1连接口,在电极导向器内形成有连接第1连接口与喷射口的第1流路。通过锥形部嵌合于嵌合孔,第1流路通过第1连接口和第1供给通路出口与第1供给通路连接。由加工液供给装置供给到第1供给通路和第1流路的加工液从喷射口喷射。上述放电加工单元能够在加工部位附近稳定供给加工液。(the invention provides an electric discharge machining unit provided with a tool electrode, a housing, an electrode guide, and a machining liquid supply device. Specifically, the tool electrode is inserted into an electrode guide. The housing has a fitting hole having a tapered surface, a1 st supply passage outlet is provided in the tapered surface, and a1 st supply passage connecting the working fluid supply device and the 1 st supply passage outlet is formed in the housing. The electrode guide includes a tapered portion having a tapered shape and an ejection port formed on a lower surface, a1 st connection port is provided on a tapered surface of the tapered portion, and a1 st flow path for connecting the 1 st connection port and the ejection port is formed in the electrode guide. The 1 st flow path is connected to the 1 st supply path through the 1 st connection port and the 1 st supply path outlet by fitting the tapered portion to the fitting hole. The machining liquid supplied to the 1 st supply passage and the 1 st flow passage by the machining liquid supply device is ejected from the ejection port. The electric discharge machining unit can stably supply the machining liquid near the machining position.)

1. An electric discharge machining unit of an electric discharge machining apparatus, comprising a tool electrode, a housing, an electrode guide, and a machining liquid supply device,

the tool electrode is inserted into the electrode guide along a central axis of the electrode guide, and performs electric discharge machining between the tool electrode and a workpiece,

The housing has a fitting hole having a tapered surface,

A1 st supply passage outlet is arranged on the conical surface,

A1 st supply passage connecting the working fluid supply device and the 1 st supply passage outlet is formed in the housing,

The electrode guide has a tapered portion having a tapered shape tapering upward and a tip, and a jet port formed on a lower surface,

a1 st connecting port is arranged on the conical surface of the conical part,

A1 st flow path connecting the 1 st connection port and the ejection port is formed in the electrode guide,

The tapered portion is fitted into the fitting hole, and the 1 st flow path is connected to the 1 st supply path through the 1 st connection port and the 1 st supply path outlet,

The machining liquid supply device supplies machining liquid to the 1 st supply passage and the 1 st flow passage,

The machining liquid is ejected from the ejection port.

2. The electrical discharge machining unit of claim 1,

The 1 st flow path includes a machining liquid filling region formed between the tool electrode and the inner surface of the electrode guide, and is connected to the injection port through the machining liquid filling region.

3. The electrical discharge machining unit according to claim 1 or claim 2,

The 1 st connecting port is provided with a1 st annular concave part and a plurality of 1 st opening parts,

The 1 st annular recess extends in a circumferential direction of the tapered portion,

The plurality of 1 st openings are formed in the bottom surface of the 1 st annular recess so as to be spaced apart from each other in the circumferential direction of the 1 st annular recess,

the 1 st connection port is connected to the 1 st channel through the 1 st opening.

4. The electrical discharge machining unit of claim 2 or claim 3 when dependent on claim 2,

The electric discharge machining unit further includes a compressed gas supply device,

a2 nd supply passage outlet is provided on the tapered surface of the housing,

A2 nd supply passage connecting the compressed gas supply device and the 2 nd supply passage outlet is formed in the housing,

A2 nd connecting port is arranged on the conical surface of the conical part,

A2 nd flow path connecting the 2 nd connection port and the ejection port is formed in the electrode guide,

the 2 nd flow path includes a compressed gas supply space and a mist generation space provided downstream of the compressed gas supply space,

The processing liquid filling region is communicated with the mist generating space and is connected with the jet orifice through the mist generating space,

the tapered portion is fitted into the fitting hole, and the 2 nd flow path is connected to the 2 nd supply path through the 2 nd connection port and the 2 nd supply path outlet,

The compressed gas supply device supplies compressed gas to the 2 nd supply passage and the 2 nd flow passage,

The machining liquid is mixed with the compressed gas in the mist generation space, atomized into a mist, and ejected from the ejection opening in the form of mist.

5. The electrical discharge machining unit of claim 4,

the 2 nd connection port is disposed closer to the lower surface of the electrode guide than the 1 st connection port.

6. The electrical discharge machining unit according to claim 4 or claim 5,

The 1 st connection port and the 2 nd connection port are disposed at different heights from each other,

at least 1 annular groove extending in a circumferential direction of the tapered portion between the 1 st connection port and the 2 nd connection port is formed on the tapered surface of the tapered portion,

an O-ring is inserted in the annular groove.

7. The electrical discharge machining unit according to any one of claim 4 to claim 6, when dependent on claim 2,

The compressed gas supply space of the 2 nd flow path includes a pair of spaces provided along the working fluid filling region.

8. the electrical discharge machining unit according to any one of claims 4 to 7,

The 2 nd connecting port is provided with a2 nd annular concave part and a plurality of 2 nd opening parts,

the 2 nd annular recess extends in a circumferential direction of the tapered portion,

the plurality of 2 nd openings are formed on the bottom surface of the 2 nd annular recess at intervals in the circumferential direction of the 2 nd annular recess,

the 2 nd connecting port is connected to the 2 nd flow path through the 2 nd opening.

9. the electrical discharge machining unit according to any one of claims 1 to 8,

The electric discharge machining unit further includes a plurality of wire guides which are arranged at intervals to conduct the tool electrodes,

a gap is provided between the tool electrode and the wire guide die.

10. The electrical discharge machining unit according to claim 9 when dependent on claim 4,

The electrode guide further includes a guide wire die fixing portion provided on a downstream side of the tapered portion,

The yarn guide die fixing section fixes at least 1 yarn guide die of the plurality of yarn guide dies, which is disposed downstream of the tapered section,

A plurality of processing liquid ejection grooves are formed on the inner surface of the guide wire die fixing portion at intervals in the circumferential direction of the inner surface of the guide wire die fixing portion,

The processing liquid filling area is communicated with the mist generation space through the processing liquid ejection groove.

11. The electrical discharge machining unit according to any one of claims 1 to 10,

the tool electrode is rotatable about the central axis.

Technical Field

The present invention relates to an electric discharge machining unit in an electric discharge machining apparatus for electric discharge machining a workpiece between tool electrodes, and more particularly to an electric discharge machining unit for performing electric discharge machining while spraying a machining liquid to a machining portion of the workpiece in air.

Background

In a machining unit mounted on various machine tools, when a workpiece is machined in air, machining is performed while removing machining chips generated during machining by spraying a machining liquid for cooling a component. Among them, in order to supply the machining liquid to the vicinity of the machining site, there is known a machining unit in which a flow path of the machining liquid or the like is formed in a component such as a housing for housing a machining tool.

patent document 1 discloses an electric discharge machining apparatus for electric discharge machining a workpiece while generating electric discharge between the workpiece and a tool electrode in air. The electric discharge machining apparatus includes an extension guide for accommodating a tool electrode, and a housing for supporting the extension guide. Wherein a working fluid flow path is formed inside the housing and the extension guide, and when the flow paths are connected to each other, the working fluid is supplied from the supply device into the flow path and is injected to the vicinity of the tip of the tool electrode.

However, the tool electrode may need to be replaced in consideration of the machining conditions such as the tool electrode consumption and the machining depth. In order to satisfy the requirement for replacement of tool electrodes having different outer diameters, it is necessary to replace the guide member of the tool electrode and the like together. Patent document 2 discloses an electric discharge machining apparatus provided with an automatic replacing device capable of replacing an electrode holder together with a plurality of tool electrodes of different outer diameters in fine hole electric discharge machining.

[ Prior Art document ]

[ patent document ]

patent document 1: japanese patent No. 6495518

Patent document 2: japanese patent No. 4152602

When the electric discharge machining unit is introduced, it is necessary to connect the flow path formed inside the housing and the guide member each time the tool electrode is replaced together with the guide member. However, when frequent replacement is performed, particularly when replacement is performed using an automatic replacement device, it is difficult to reliably position the guide member, thus hindering the introduction of the electric discharge machining unit described above.

Disclosure of Invention

The present invention has been made in view of the above circumstances, and a main object thereof is to provide an electric discharge machining unit that can reliably and easily connect flow paths between constituent members when mounted on an electric discharge machining apparatus, and can stably supply a machining liquid to a machining-site attachment.

According to the present invention, an electric discharge machining unit of an electric discharge machining apparatus includes a tool electrode, a housing, an electrode guide, and a machining liquid supply device. Wherein the tool electrode is inserted into the electrode guide along a central axis of the electrode guide and performs electric discharge machining between the tool electrode and a workpiece, the housing includes a fitting hole having a tapered surface, a1 st supply passage outlet is provided in the tapered surface, a1 st supply passage connecting the machining fluid supply device and the 1 st supply passage outlet is formed in the housing, the electrode guide includes a tapered portion having a tapered shape tapered upward toward a tip end and an ejection port formed in a lower surface, a1 st connection port is provided in the tapered surface of the tapered portion, a1 st flow path connecting the 1 st connection port and the ejection port is formed in the electrode guide, the 1 st flow path is fitted into the fitting hole via the tapered portion, and the 1 st flow path is connected to the 1 st supply passage via the 1 st connection port and the 1 st supply passage outlet, the machining liquid supply device supplies a machining liquid to the 1 st supply passage and the 1 st flow passage, and the machining liquid is ejected from the ejection port.

The invention has the following effects: in the electric discharge machining unit according to the present invention, since the tapered portion is fitted to the housing, the position of the electrode guide in the central axis direction thereof with respect to the housing is uniquely determined, and therefore, the 1 st supply passage and the 1 st flow passage can be easily connected. Also, since the connection between the flow paths between the constituent members is more reliable and easier when the electrode guide is mounted to the electric discharge machining apparatus, it is possible to introduce it into an electric discharge machining apparatus in which the process of the electrode guide is frequently performed and the electrode guide is automatically replaced, and to stably supply the machining liquid.

Hereinafter, various embodiments of the present invention will be described by way of examples. The embodiments shown below may be combined with each other.

The 1 st flow path preferably includes a machining liquid filling region formed between the tool electrode and the inner surface of the electrode guide, and is connected to the injection port through the machining liquid filling region.

Preferably, the 1 st connection port includes a1 st annular recess extending in a circumferential direction of the tapered portion, and a plurality of 1 st openings formed in a bottom surface of the 1 st annular recess so as to be spaced apart from each other in the circumferential direction of the 1 st annular recess, and the 1 st connection port is connected to the 1 st flow path through the 1 st opening.

preferably, the electric discharge machining unit further includes a compressed gas supply device, a2 nd supply passage outlet is provided on the tapered surface of the housing, a2 nd supply passage connecting the compressed gas supply device and the 2 nd supply passage outlet is formed in the housing, a2 nd connection port is provided on the tapered surface of the tapered portion, a2 nd flow passage connecting the 2 nd connection port and the ejection port is formed in the electrode guide, the 2 nd flow passage includes a compressed gas supply space and a mist generation space provided on a downstream side of the compressed gas supply space, the machining liquid filling region communicates with the mist generation space, is connected to the ejection port via the mist generation space, is fitted to the fitting hole via the tapered portion, and the 2 nd flow passage is connected to the 2 nd supply passage via the 2 nd connection port and the 2 nd supply passage outlet, the compressed gas supply device supplies compressed gas to the 2 nd supply passage and the 2 nd flow passage, and the working fluid is mixed with the compressed gas in the mist generation space, atomized into a mist, and ejected from the ejection opening in the form of mist.

The 2 nd connection port is preferably disposed closer to the lower surface of the electrode guide than the 1 st connection port.

Preferably, the 1 st connection port and the 2 nd connection port are disposed at different heights from each other, and at least 1 annular groove is formed on the tapered surface of the tapered portion, extending in a circumferential direction of the tapered portion between the 1 st connection port and the 2 nd connection port, and an O-ring is fitted into the annular groove.

the compressed gas supply space of the 2 nd flow path preferably includes a pair of spaces provided along the working fluid filled region.

Preferably, the 2 nd connecting port includes a2 nd annular recess extending in a circumferential direction of the tapered portion, and a plurality of 2 nd openings formed in a bottom surface of the 2 nd annular recess so as to be spaced apart from each other in the circumferential direction of the 2 nd annular recess, and the 2 nd connecting port is connected to the 2 nd flow path through the 2 nd opening.

Preferably, the electric discharge machining unit further includes a plurality of wire guides disposed at intervals to conduct the tool electrode, and a gap is provided between the tool electrode and the wire guides.

preferably, the electrode guide further includes a guide wire die fixing portion provided on a downstream side of the tapered portion, the guide wire die fixing portion fixes at least 1 of the plurality of guide wire dies, the guide wire die fixing portion being disposed on a downstream side of the tapered portion, a plurality of processing liquid discharge grooves are formed on an inner surface of the guide wire die fixing portion, the processing liquid discharge grooves being provided in a circumferential direction and at intervals on the inner surface of the guide wire die fixing portion, and the processing liquid filling region is communicated with the mist generation space through the processing liquid discharge grooves.

Preferably said tool electrode is rotatable about said central axis.

Drawings

Fig. 1 is a sectional view of the front surface of an electric discharge machining unit according to an embodiment of the present invention, taken on a plane passing through the center axis of an electrode guide.

fig. 2 is an exploded view of an electric discharge machining unit according to an embodiment of the present invention.

Fig. 3 is a perspective view of an electrode guide according to an embodiment of the present invention.

Fig. 4 is a front view of an electrode guide according to an embodiment of the present invention.

fig. 5 is a sectional view of an electrode guide according to an embodiment of the present invention.

3 figure 3 6 3 is 3a 3 cross 3- 3 sectional 3 view 3a 3- 3a 3 of 3 the 3 electrode 3 guide 3 of 3 figure 3 5 3. 3

Figure 7 is a cross-sectional view B-B of the electrode guide of figure 5.

Fig. 8 is an enlarged view of a portion C shown in fig. 5.

Figure 9 is a cross-sectional view D-D of the electrode guide of figure 8.

Detailed Description

Embodiments of the present invention will be described below with reference to the accompanying drawings. Various technical features shown in the embodiments described below may be combined with each other. In addition, various technical features may also independently constitute the present invention.

1. structure of electric discharge machining unit

as shown in fig. 1, an electric discharge machining unit 100 according to an embodiment of the present invention performs electric discharge machining while spraying mist of a machining liquid onto a machining portion of a workpiece (not shown). The electric discharge machining unit 100 includes a tool electrode 1, an electrode guide 2, a housing 3, a machining liquid supply device 5, and a compressed gas supply device 6. In fig. 1, arrows (white arrows) directed to the electric discharge machining unit 100 from above and right of the electric discharge machining unit 100 indicate the compressed gas supplied from the compressed gas supply device 6, and arrows directed to the electric discharge machining unit 100 from the machining liquid supply device 5 indicate the pressurized machining liquid supplied from the machining liquid supply device 5.

1.1. Tool electrode

The tool electrode 1 is a cylindrical tubular electrode having a hollow hole formed therein, and may have an outer diameter of 0.3mm to 3.0mm (millimeters), for example. The tool electrode 1 is inserted through the electrode guide 2 so as to protrude at least at the tip along the central axis of the electrode guide 2, and generates electric discharge by applying a voltage between the workpieces. In the electric discharge machining, the tool electrode 1 is rotatable about the central axis of the electrode guide 2 by a rotation driving portion (not shown) located above the electric discharge machining unit 100. The compressed gas is supplied from the compressed gas supply device 6 into the hollow hole of the tool electrode 1, and is injected into the processing portion of the object to be processed. The tool electrode 1 in the present embodiment is a tubular electrode having a hollow hole with a circular cross section, but a tubular electrode having an arbitrary shape and a plurality of hollow holes, or a rod-shaped electrode having no hollow hole may be used. Further, the tip portion of the tool electrode 1 may have any shape as long as the electrode guide 2 can be inserted.

1.2. Shell body

As shown in fig. 1 and 2, the housing 3 includes a fitting hole 3a having a tapered surface 3b, and is supported by a support mechanism (not shown) located above the electric discharge machining unit 100. The 1 st supply passage outlet 7a and the 2 nd supply passage outlet 8a are provided on the tapered surface 3b of the housing 3. A1 st supply passage 7 connecting the working fluid supply device 5 and the 1 st supply passage outlet 7a, and a2 nd supply passage 8 connecting the compressed gas supply device 6 and the 2 nd supply passage outlet 8a are formed inside the housing 3. The 1 st supply passage 7 is a passage for supplying pressurized working fluid from the working fluid supply device 5 to the electrode guide 2, and the 2 nd supply passage 8 is a passage for supplying compressed gas from the compressed gas supply device 6 to the electrode guide 2.

1.3. Working fluid supply device

The working fluid supply device 5 is used to supply pressurized working fluid. Examples of the processing liquid include water, water-soluble processing liquids, and oil-based processing liquids. In the present embodiment, water is used as the processing liquid.

1.4. compressed gas supply device

The compressed gas supply device 6 is used to supply compressed gas. As the compressed gas, for example, air, oxygen, nitrogen, argon, or the like can be used. In the present embodiment, air is used as the compressed gas.

1.5. Electrode guider

As shown in fig. 3 and 4, the electrode guide 2 includes: the yarn guide device includes a tapered portion 2a having a tapered shape tapered upward at the tip, a yarn guide die fixing portion 2c provided below the tapered portion 2a (downstream side in the flow direction of the compressed gas), and a jet port 2d formed in the lower surface. The electrode guide 2 is attached to be detachable from a pulling mechanism (not shown) located above the electric discharge machining unit 100 in a state biased upward by a spring (not shown) provided in the pulling mechanism. The tapered surface 2b of the tapered portion 2a is provided with a1 st connection port 9a and a2 nd connection port 10a each having an annular recess extending in the circumferential direction of the tapered portion 2a, and the 2 nd connection port 10a is disposed at a position closer to the lower surface of the electrode guide 2 than the 1 st connection port 9 a.

As shown in fig. 1, 2, and 5, a1 st channel 9 connecting the 1 st connection port 9a and the ejection port 2d is formed inside the electrode guide 2. The 1 st flow path 9 is connected to a1 st supply path 7, which will be described later, as a flow path of the pressurized working fluid supplied from the working fluid supply device 5. The 1 st flow path 9 includes a machining liquid filling region 9c formed between the tool electrode 1 inserted through the center axis of the electrode guide 2 and the inner surface of the electrode guide 2. That is, the 1 st flow path 9 is connected to the ejection opening 2d through the working fluid filling region 9 c. When the working fluid supply device 5 supplies the pressurized working fluid to the 1 st supply passage 7 and the 1 st flow passage 9, the working fluid fills the working fluid filling region 9 c. Thus, the tool electrode 1 inserted into the working fluid filling region 9c can be effectively cooled by the working fluid flowing through the working fluid filling region 9c, and consumption of the tool electrode 1 during electric discharge machining can be suppressed.

as shown in fig. 3 to 6, the 1 st connection port 9a includes a1 st annular recessed portion 9a1 and a plurality of 1 st opening portions 9a2 formed in the bottom surface of the 1 st annular recessed portion 9a1 so as to be spaced apart from each other in the circumferential direction of the 1 st annular recessed portion 9a1, and the 1 st connection port 9a is connected to the 1 st flow path 9 through the plurality of 1 st opening portions 9a 2. In the present embodiment, 2 1 st openings 9a2 are formed at opposing positions in the circumferential direction of the 1 st annular recess 9a 1. When the working fluid supply device 5 supplies the pressurized working fluid to the 1 st supply passage 7 and the 1 st flow passage 9, the working fluid is delivered to the 1 st flow passage 9 through the 2 1 st openings 9a 2. This enables the machining liquid to flow stably in the machining liquid filling region 9c without any difference. In the present embodiment, the number of the 1 st openings 9a2 is 2, but 3 or more of the 1 st openings 9a2 may be provided, and the 1 st openings 9a2 are preferably arranged at equal angles in the circumferential direction of the 1 st annular recess 9a 1.

as shown in fig. 3 to 5 and 7, the electrode guide 2 further includes a2 nd flow path 10 connecting the 2 nd connection port 10a and the ejection port 2 d. The 2 nd flow path 10 is connected to a2 nd supply path 8 to be mentioned later as a flow path of the compressed gas supplied from the compressed gas supply device 6. The 2 nd flow path 10 includes a compressed gas supply space 10c and a mist generation space 10e provided below the compressed gas supply space 10c (downstream side in the compressed gas flow direction).

The compressed gas supply space 10c includes a pair of spaces 10d provided along the working fluid filled region 9 c. In the present embodiment, a pair of spaces 10d are provided with the working fluid filling region 9c therebetween. When the compressed gas supply device 6 supplies the compressed gas to the 2 nd supply passage 8 and the 2 nd flow passage 10, the compressed air is sent to the mist generating space 10e via the pair of spaces 10 d. This makes it possible to make the air flow delivered to the mist generating space 10e uniform.

The 2 nd connecting port 10a includes a2 nd annular recessed portion 10a1 and a plurality of 2 nd opening portions 10a2 formed at the bottom surface of the 2 nd annular recessed portion 10a1 so as to be spaced apart from each other in the circumferential direction of the 2 nd annular recessed portion 10a1, and the 2 nd connecting port 10a is connected to the 2 nd flow path 10 through the plurality of 2 nd opening portions 10a 2. In the present embodiment, 2 nd openings 10a2 are formed at opposite positions in the circumferential direction of the 2 nd annular recess 10a 1. When the compressed gas supply device 6 supplies the compressed air to the 2 nd supply passage 8 and the 2 nd flow path 10, the compressed air flows into the 2 nd flow path 10 through the 2 nd opening portions 10a 2. In the present embodiment, the 2 nd opening portions 10a2 are connected to the pair of spaces 10d of the compressed gas supply space 10c, respectively, and thus the compressed air can be stably supplied to the mist generating space 10e without distinction.

As described above, in the present embodiment, the 2 nd connecting port 10a is provided at a position closer to the lower surface of the electrode guide 2 than the 1 st connecting port 9 a. Since the tapered portion 2a of the electrode guide 2 has a tapered shape expanding downward and the connection ports are disposed, a flow path of the pressurized machining liquid and the compressed air can be provided in the electrode guide 2, and a sufficient space can be secured.

As shown in fig. 5, the tool electrode 1 is conducted into the working fluid filling region 9c, and a plurality of guide wires are arranged so as to be separated from each other, and a gap is provided between the tool electrode 1 and the guide wires. In the present embodiment, 3 guide dies 17a, 17b, and 17c are arranged, in which the guide die 17a is arranged at the upper end of the working fluid filling region 9c, the guide die 17c is arranged at the lower end of the working fluid filling region 9c, and the guide die 17b is arranged between the guide die 17a and the guide die 17 c. Gaps 19a, 19b, 19c are provided between the wire guides 17a, 17b, 17c and the tool electrode 1, respectively.

The guide wire dies 17a, 17b, and 17c can prevent the center runout of the tool electrode 1 generated in the electric discharge machining and the accompanying displacement of the machining position, and can perform high-precision machining. The pressurized processing liquid is caused to flow through the gaps 19a, 19b, and 19c between the tool electrode 1 and the guide wire dies 17a, 17b, and 17c, and a negative pressure can be generated by the venturi effect at a position where the processing liquid flows out from the guide wire dies. A small amount of the processing liquid can be ejected by the pressure difference.

Specifically, the electric discharge machining unit according to the present invention can discharge the machining fluid in the machining fluid filling region 9c from the gap 19a between the tool electrode 1 and the wire guide 17a at the upper end portion of the machining fluid filling region 9c, thereby cooling the machining tool protruding above the machining fluid filling region 9 c. The working fluid in the working fluid filling region 9c can be discharged from the gap 19c between the tool electrode 1 and the wire guide 17c to the mist generating space 10e at the lower end of the working fluid filling region 9 c. The size of the gap is preferably 0.0025mm to 0.010 mm.

As shown in fig. 5 and 8, the guide wire mold fixing portion 2c of the electrode guide 2 fixes at least 1 guide wire mold of the plurality of guide wire molds, which is provided on the downstream side of the tapered portion 2 a. In the present embodiment, the godet dies 17b, 17c are fixed by the inner surface of the godet die fixing portion 2 c. As shown in fig. 9, a plurality of processing liquid discharge grooves 9d are formed on the inner surface of the guide wire die fixing portion 2c at intervals in the circumferential direction of the inner surface of the guide wire die fixing portion 2 c. In the present embodiment, 4 processing liquid ejection grooves 9d each having a semicircular shape with the same diameter in cross section are formed at intervals of 90 degrees in the circumferential direction of the inner surface of the guide wire fixing portion 2c and along the central axis direction of the electrode guide 2.

with this configuration, the pressurized working fluid in the working fluid filled region 9c is supplied to the mist generating space 10e through the working fluid ejection groove 9d without distinction, and mist can be generated in the mist generating space 10e and stably ejected from the ejection port 2 d. Further, since the flow rate of the working fluid can be adjusted by adjusting the number and size of the working fluid discharge grooves 9d, the flow rate can be adjusted without further processing for a wire guide die generally formed by using a difficult-to-cut material such as sapphire.

Further, by circulating the pressurized working fluid through the working fluid ejection groove 9d, a negative pressure can be generated by the venturi effect at a position where the pressurized working fluid flows out from the working fluid ejection groove 9 d. By this pressure difference, the machining liquid can be ejected from the machining liquid ejection groove 9d, and the mist can be generated more efficiently in the mist generation space 10 e. The number, shape, arrangement, and the like of the processing liquid discharge grooves 9d are not limited to the above configuration, but it is preferable that the processing liquid discharge grooves 9d of the same size and shape are provided at the same angle in the circumferential direction of the inner surface of the guide wire mold fixing portion 2c, and in the case of the processing liquid discharge grooves 9d having a substantially semicircular cross section, the radius thereof is preferably 0.1mm to 0.4 mm.

as shown in fig. 3 to 5, at least 1 annular groove 13 extending in the circumferential direction of the tapered portion 2a is formed in the tapered surface 2b of the tapered portion 2a, and an O-ring 14 is fitted in the annular groove 13. At least 1 of the annular grooves 13 is formed between the 1 st connection port 9a and the 2 nd connection port 10 a. In the present embodiment, the annular grooves 13 are formed at 3 positions above the 1 st connection port 9a, between the 1 st connection port 9a and the 2 nd connection port 10a, and below the 2 nd connection port 10a, and the O-rings 14 are fitted thereto.

As shown in fig. 1 and 2, since the electrode guide 2 is biased upward by the pulling mechanism in a state of being fitted to the case 3, the O-ring 14 fitted into the annular groove 13 is in a state of being squashed by the bottom surface of the annular groove 13 and the tapered surface 3b of the case 3. Thereby, the 1 st connection port 9a and the 2 nd connection port 10a are sealed at both sides by the O-rings 14 along the tapered surface 2b of the tapered portion 2 a. This prevents the machining liquid and the compressed gas leaking from the connection port from further leaking to the outside of the electrode guide 2.

2. Electrode guide and method for mounting tool electrode

As shown in fig. 1 and 2, when the electrode guide 2 is attached, the tapered portion 2a of the electrode guide 2 is fitted into the fitting hole 3a of the housing 3 from below so that the tapered surface 2b of the tapered portion 2a is in close contact with the tapered surface 3b of the housing 3, the 1 st flow path 9 and the 1 st supply path 7 are connected to each other via the 1 st connection port 9a and the 1 st supply path outlet 7a, and the 2 nd flow path 10 and the 2 nd supply path 8 are connected to each other via the 2 nd connection port 10a and the 2 nd supply path outlet 8 a. Thereby, the respective flow paths of the working fluid and the compressed air formed inside the electrode guide 2 and the housing 3 are connected to each other.

Thus, by fitting the tapered portion 2a into the fitting hole 3a, the position of the electrode guide 2 relative to the housing 3 in the direction of the central axis of the electrode guide 2 can be uniquely determined, and the flow path and the supply path can be easily connected. In addition, in the present embodiment, since the 1 st connection port 9a and the 2 nd connection port 10a are provided with the annular concave portions extending in the circumferential direction of the tapered portion 2a, the 1 st supply passage outlet 7a and the 2 nd supply passage outlet 8a can be connected to each other at arbitrary positions in the circumferential direction, and the connection between the connection flow path and the supply passage becomes more reliable and easier.

The electrode guide 2 fitted to the housing 3 is attached to a pulling mechanism (not shown) located above the electric discharge machining unit 100. In this state, the tool electrode 1 is inserted from above or below the electrode guide 2 along the central axis of the electrode guide 2, and is attached to a rotation driving unit (not shown) located above the electric discharge machining unit 100.

3. mist generation in electric discharge machining

The mist generation process in the electric discharge machining will be described in detail below.

as shown in fig. 1, 5, 8, and 9, in the present embodiment, the machining-fluid-filled region 9c communicates with the mist generating space 10e through the gap 19c and the machining-fluid ejection groove 9 d. Therefore, the pressurized working fluid supplied from the working fluid supply device 5 is ejected from the working fluid filling region 9c to the mist generation space 10e through the gap 19c and the working fluid ejection groove 9d, mixed with the compressed gas in the mist generation space 10e, atomized into a mist, and then ejected from the ejection port 2d along the tool electrode 1 as a mist. This enables the machining chips near the machining site to be removed efficiently. Further, as described above, the tool electrode 1 is rotatable by the rotation driving section. So that the mist ejected from the ejection openings 2d can be further uniformly diffused.

When the machining liquid is sprayed in a mist form, the mist is preferably generated on the lower side of the electric discharge machining unit 100 near the machining site. When the working fluid is mixed with the compressed air at a position away from the machining site, the generated mist is aggregated while being transferred to the machining site, and the size of the mist particles increases, so that the effect of removing the machining chips is reduced. In the present embodiment, the 1 st connection port and the 2 nd connection port are provided at different heights from each other, and both sides of the 1 st connection port 9a and the 2 nd connection port 10a are sealed with the O-rings 14 along the tapered surface 2b of the tapered portion 2a, respectively, so that the processing liquid and the compressed gas leaking from the respective connection ports can be prevented from being mixed before reaching the mist generating space 10 e. Thus, high-quality mist can be generated and can be stably conveyed to a machining part.

4. Other embodiments

Although the preferred embodiments of the present invention have been described above, the present invention is not limited to the above embodiments and examples, and various design changes described in the claims are also possible.

In the above embodiment, the housing 3 and the electrode guide 2 are provided with 2 kinds of flow paths of compressed air and pressurized working fluid, respectively, which mix the working fluid and the compressed air and spray them as mist. In another embodiment, only the flow path of the pressurized machining liquid may be provided, and the machining liquid may be ejected from the ejection port 2d formed on the lower surface of the electrode guide 2.

the industrial applicability of the present application lies in: as described above, according to the present invention, there is provided an electric discharge machining unit capable of reliably and easily connecting flow paths between constituent members when the unit is mounted on an electric discharge machining apparatus, and stably supplying a machining liquid to a machining position fixture. Specifically, the electric discharge machining unit according to the present invention is applicable to a fine hole electric discharge machining device, an engraving electric discharge machining device, a mist electric discharge machining device, and the like.

[ notation ] to show

1: tool electrode

2: electrode guider

2 a: tapered portion

2 b: conical surface

2 c: thread guide die fixing part

2 d: jet orifice

3: shell body

3 a: tabling hole

3 b: conical surface

5: working fluid supply device

6: compressed gas supply device

7: 1 st supply path

7 a: 1 st supply passage outlet

8: no. 2 supply path

8 a: 2 nd supply passage outlet

9: 1 st flow path

9 a: the 1 st connection port

9a 1: 1 st annular recess

9a 2: 1 st opening part

9 c: working fluid filled region

9 d: processing liquid ejection groove

10: 2 nd flow path

10 a: the 2 nd connecting port

10a 1: 2 nd annular recess

10a 2: opening part 2

10 c: compressed gas supply space

10 d: space(s)

10 e: mist generating space

13: annular groove

14: o-shaped ring

17 a: thread guiding die

17 b: thread guiding die

17 c: thread guiding die

19 a: gap

19 b: gap

19 c: gap

100: electric discharge machining unit