JP6902587B2 - Replacement parts unit for plasma torch - Google Patents

Description

The present invention relates to a replacement component unit for a plasma torch.

In a plasma torch, an arc is formed between an electrode and a work (material to be cut) and narrowed down by a nozzle to generate a plasma arc, which is a high-temperature and high-speed jet jet suitable for cutting. Therefore, the electrodes and nozzles need to be electrically insulated from each other. Further, in order to obtain good cutting quality, it is important to form a jet jet symmetrical with respect to the central axis of the torch. For that purpose, the central axis of the electrode and the nozzle must be aligned.

For example, as shown in Patent Document 1, the plasma torch has an electrode as a generation point of an arc and a nozzle arranged so as to cover the electrode. The electrodes are attached to the electrode pedestal of the torch body. The nozzle is attached to the electrode via an insulating guide. The insulation guide positions the nozzle so that it is concentric with the electrodes. The plasma torch generates a plasma arc between the electrode and the workpiece through the orifice of the nozzle.

Since the electrodes, insulation guides, and nozzles are consumables, they are detachably attached to each other so that they can be manually replaced. Further, O-rings are arranged between the electrode and the insulating guide and between the insulating guide and the nozzle, respectively. As a result, the cooling water or plasma gas is sealed.

Japanese Unexamined Patent Publication No. 2001-47247

The degree of concentricity between the electrodes and the nozzle affects the quality of plasma cutting. However, in the above plasma torch, since the electrodes, the insulating guide, and the nozzle are manually attached to and detached from each other, there is a gap between the parts. Due to these gaps, the center position of the electrode and the nozzle may be displaced.

Alternatively, when an O-ring is used, the O-ring is provided with a crushing allowance for a water seal and a gas seal in order to allow manual insertion and removal of nozzles and electrodes. However, since the nozzle and electrodes can be manually inserted and removed, the bonding force of the O-ring crushing allowance cannot be increased. Therefore, the fixing method using the O-ring is not a strong fixing method that does not cause misalignment. Further, by tightening the retainer cap, when the nozzle, the guide, and the electrode are pressed against the torch body, the O-ring may be deformed unevenly due to the force due to the twist. In that case, the center position of the electrode and the nozzle may be displaced.

Further, in the above plasma torch, the electrode, the insulating guide, and the nozzle are individually replaced. For example, when replacing the electrode, the nozzle and the insulating guide are removed from the electrode, the electrode is replaced, and then the nozzle and the insulating guide are attached. Therefore, the replacement work of parts is complicated. Also, replacing parts may affect the concentricity of the electrodes and nozzles.

An object of the present invention is to provide a replacement component unit for a plasma torch, which can improve the concentricity between an electrode and a nozzle and can be easily replaced.

The plasma torch replacement component unit according to the first aspect of the present invention includes an electrode, a resin insulating guide, and a nozzle. The insulation guide has a hole into which the electrode is inserted. The insulation guide is joined to the electrode by press fitting. The nozzle has a hole into which the insulating guide is inserted. The nozzle is joined to the insulation guide by press fitting. The electrodes and insulation guides are joined together to seal the fluid without an O-ring. The insulation guide and nozzle are joined together to seal the fluid without an O-ring.

In the plasma torch replacement component unit according to this embodiment, the electrodes, the insulating guide, and the nozzle are joined so as not to be easily separated. Therefore, the electrodes, the insulating guide, and the nozzle can be easily replaced by replacing the replacement component unit. Further, since the electrode, the insulating guide, and the nozzle are joined by press fitting or adhesion, the electrode, the insulating guide, and the nozzle can be joined without using an O-ring. As a result, the degree of concentricity between the electrode and the nozzle can be improved.

The outer peripheral surface of the electrode may have an uneven shape that engages with the inner peripheral surface of the insulating guide. The inner peripheral surface of the insulating guide may have a concavo-convex shape that engages with the outer peripheral surface of the electrode. Depending on the uneven shape of the electrode and the uneven shape of the insulating guide, the insulating guide may be prevented from coming off from the electrode.

The outer peripheral surface of the insulating guide may have an uneven shape that locks to the inner peripheral surface of the nozzle. The inner peripheral surface of the nozzle may have an uneven shape that engages with the outer peripheral surface of the insulating guide. Depending on the uneven shape of the insulating guide and the uneven shape of the nozzle, the nozzle may be prevented from coming off from the insulating guide.

The insulation guide may be made of a material having a modulus of elasticity less than that of the ceramic.

The electrode may have a joint portion and a flange portion. The joint may be joined to the insulation guide. The flange portion has a larger outer diameter than the joint portion and may include the base end of the electrode.

The outer peripheral surface of the flange portion may have a sealing surface that comes into contact with the O-ring.

The flange portion may be longer than the joint portion in the axial direction of the electrode.

The outer peripheral surface of the insulating guide may have a first outer peripheral surface and a second outer peripheral surface. The first outer peripheral surface may be arranged in the nozzle and joined to the nozzle. The second outer peripheral surface may be located on the proximal end side of the first outer peripheral surface and may be arranged outside the nozzle. In the axial direction of the insulation guide, the first outer peripheral surface may be shorter than the second outer peripheral surface.

The second outer peripheral surface may have a sealing surface that comes into contact with the O-ring.

The portion of the second outer peripheral surface on the tip side of the sealing surface may be arranged in the cooling water passage of the plasma torch.

The outer peripheral surface of the insulating guide may further have a third outer peripheral surface. The third outer peripheral surface may be located on the proximal end side of the second outer peripheral surface and may have an outer diameter smaller than that of the second outer peripheral surface. The third outer peripheral surface may be arranged in the gas passage of the plasma torch.

The nozzle may have a first nozzle portion and a second nozzle portion. The first nozzle portion may be joined to the insulating guide. The second nozzle portion is located on the tip end side of the first nozzle portion, has a larger radial thickness than the first nozzle portion, and may face the electrode. In the axial direction of the nozzle, the second nozzle portion may be longer than the first nozzle portion.

The base end of the nozzle may be located in the cooling water passage of the plasma torch.

The outer peripheral surface of the nozzle may have a recess that is recessed inward in the radial direction and extends in the circumferential direction.

In the axial direction of the nozzle, the recess may be arranged at substantially the same position as the tip of the electrode.

The plasma torch may include a retainer cap that is placed so as to cover the nozzle. The recess may be arranged in the cooling water passage between the inner peripheral surface of the retainer cap and the outer peripheral surface of the nozzle. The retainer cap may be provided with a hole communicating with the cooling water passage. In the axial direction of the nozzle, the recess may be arranged at substantially the same position as the hole of the retainer cap.

The wall surface on the base end side of the recess is inclined with respect to the radial direction of the nozzle, and may extend parallel to the inner peripheral surface of the retainer cap.

The wall surface on the tip end side of the recess may extend in the radial direction of the nozzle.

The plasma torch replacement component unit may further include an insulating ring and a shield cap. The insulating ring has a hole into which the nozzle is inserted and may be joined to the nozzle by press fitting or adhesion. The shield cap has a hole into which the insulating ring is inserted and may be joined to the insulating ring by press fitting or adhesion.

The plasma torch may have a first retainer cap and a second retainer cap. The first retainer cap has an opening into which the plasma torch replacement component unit is inserted and may be arranged so as to cover the nozzle. The second retainer cap has an opening into which the plasma torch replacement component unit is inserted, and may be attached to the first retainer cap so as to cover the first retainer cap. The nozzle or shield cap may have a flange portion. The flange portion may be sandwiched and held by the edge portion of the opening of the first retainer cap and the edge portion of the opening of the second retainer cap.

The electrodes include an electrode main body, a joint located on the base end side of the electrode main body, a flange portion located on the base end side of the joint, and a step portion provided between the flange and the joint. , May be included. The insulation guides are located on the first outer peripheral surface arranged in the nozzle, the base end side of the first outer peripheral surface, the second outer peripheral surface arranged outside the nozzle, the first inner peripheral surface, and the first. It may include a second inner peripheral surface located closer to the base end surface than the inner peripheral surface and reaching the base end surface of the insulating guide. The nozzle includes a third inner peripheral surface reaching the base end surface of the nozzle, a fourth inner peripheral surface located on the tip side of the third inner peripheral surface, and a third inner peripheral surface and a fourth inner peripheral surface. It may include an inner step portion provided between them. The base end surface of the insulation guide may abut on the stepped portion of the electrode. The second inner peripheral surface of the insulation guide may be joined to the joint portion of the electrode by press fitting. The tip surface of the insulating guide may abut on the inner step portion of the nozzle. The first outer peripheral surface of the insulation guide may be joined to the third inner peripheral surface of the nozzle by press fitting. The length from the base end surface of the nozzle to the inner step portion may be shorter than the length of the second outer peripheral surface of the insulating guide. The flange portion may include the proximal end of the electrode.

The outer peripheral surface of the insulation guide is located inside the nozzle and is located on the base end side of the first outer peripheral surface and the first outer peripheral surface to be joined to the nozzle, and is arranged outside the nozzle and has a smaller diameter than the first outer peripheral surface. It may have a second outer peripheral surface and a third outer peripheral surface which is located on the base end side of the second outer peripheral surface, is connected to an electrode, and has a diameter smaller than that of the second outer peripheral surface.

According to the present invention, it is possible to provide a replacement component unit for a plasma torch that can improve the concentricity between the electrode and the nozzle and can be easily replaced.

It is sectional drawing along the central axis of the plasma torch which concerns on 1st Embodiment. It is an exploded view of a plasma torch. It is a side view of a replacement part unit. It is sectional drawing along the central axis of a replacement part unit. It is a perspective view of an electrode. It is a perspective view of an electrode. It is sectional drawing of an electrode. It is a perspective view of the insulation guide. It is a perspective view of the insulation guide. It is sectional drawing of the insulation guide. It is the figure which looked at the insulation guide from the base end side. It is sectional drawing of the insulation guide including the axis of the communication passage. It is a perspective view of a nozzle. It is a perspective view of a nozzle. It is sectional drawing of a nozzle. It is a perspective view of the insulation ring. It is a perspective view of the insulation ring. It is sectional drawing of the insulation ring. It is a perspective view of a shield cap. It is a perspective view of a shield cap. It is sectional drawing of the shield cap. FIG. 21 is a cross-sectional view taken along the line AA of FIG. It is a perspective view of a center pipe. It is a perspective view of a center pipe. It is sectional drawing of a center pipe. It is a perspective view of a pipe body. It is a perspective view of a contactor. It is the figure which looked at the contactor from the axial direction. It is an enlarged view of the structure of the replacement part unit and its surroundings in FIG. It is a cross-sectional view different from FIG. 1 along the central axis of the plasma torch. FIG. 30 is an enlarged view of the configuration of the replacement part unit and its surroundings in FIG. It is sectional drawing along the central axis of the plasma torch which concerns on 2nd Embodiment. It is sectional drawing of the replacement part unit which concerns on 2nd Embodiment. It is a perspective view of the replacement part unit which concerns on 2nd Embodiment. It is a perspective view of the replacement part unit which concerns on 2nd Embodiment. It is a perspective view of the nozzle which concerns on 2nd Embodiment. It is a perspective view of the nozzle which concerns on 2nd Embodiment. It is sectional drawing along the central axis of the plasma torch which concerns on another embodiment.

1. 1. First Embodiment 1.1 Configuration of Plasma Torch Hereinafter, the plasma torch according to the embodiment will be described with reference to the drawings. FIG. 1 is a cross-sectional view taken along the central axis of the plasma torch 1a according to the first embodiment. FIG. 2 is an exploded view of the plasma torch 1a. In the present embodiment, the plasma torch 1a is a plasma torch 1a for cutting oxygen plasma. However, the plasma torch 1a may be a plasma torch for plasma cutting using a gas containing no oxygen such as nitrogen or argon.

As shown in FIG. 2, the plasma torch 1a has a replacement part unit 2a, a torch main body 3, a first retainer cap 4, and a second retainer cap 5. The replacement part unit 2a, the first retainer cap 4, and the second retainer cap 5 are arranged concentrically with the central axis of the torch body 3.

As shown in FIG. 1, the replacement part unit 2a is attached to the torch body 3. The replacement component unit 2a has an electrode 6, an insulating guide 7, a nozzle 8, an insulating ring 9, and a shield cap 10. The replacement part unit 2a will be described in detail later.

The torch body 3 is attached to the connecting pipe 32 via the fixing ring 31. The torch body 3 has a base portion 33, an electrode pedestal 34, a center pipe 20, a nozzle pedestal 36, an insulating sleeve 37, and a holder 38. The base portion 33, the electrode pedestal 34, the center pipe 20, the nozzle pedestal 36, the insulating sleeve 37, and the holder 38 are arranged concentrically with the central axis of the torch body 3.

The base portion 33 has a cylindrical shape. The base portion 33 is made of a conductor. The center pipe 20, the electrode pedestal 34, and the insulating sleeve 37 are inserted into the holes of the base portion 33. The electrode pedestal 34 has a circular tubular shape. The electrode pedestal 34 is made of a conductor. The base portion 33 is electrically connected to a cable from a power source (not shown).

The center pipe 20 is inserted into the hole of the electrode pedestal 34. The center pipe 20 has a tubular shape. The center pipe 20 is made of a conductor. The tip of the center pipe 20 projects from the tip of the nozzle pedestal 36. The center pipe 20 will be described in detail later.

The insulating sleeve 37 has a circular tubular shape. The insulating sleeve 37 is made of an insulator. A part of the insulating sleeve 37 is arranged in the hole of the base portion 33. The insulating sleeve 37 is located between the electrode pedestal 34 and the nozzle pedestal 36.

The nozzle pedestal 36 has a circular tubular shape. The tip of the nozzle pedestal 36 has a tapered shape. The nozzle pedestal 36 is made of an insulator. A contactor (not shown) that makes electrical contact with the nozzle is attached to the nozzle pedestal 36. The contacts are electrically connected to the cable from the power supply. The base portion 33 is inserted into the hole of the nozzle pedestal 36. The insulating sleeve 37 is inserted into the hole of the nozzle pedestal 36. The tip of the insulating sleeve 37 protrudes from the base 33 and is arranged in the hole of the nozzle pedestal 36.

The holder 38 has a circular tubular shape. The holder 38 is attached to the connecting pipe 32 by means such as adhesion. The nozzle pedestal 36 is inserted into the hole of the holder 38. The tip of the nozzle pedestal 36 projects from the holder 38.

The first retainer cap 4 has a cylindrical shape with a tapered tip. The first retainer cap 4 is attached to the torch body 3 so as to cover the nozzle pedestal 36. The tip of the first retainer cap 4 has an opening 41 into which the shield cap 10 is inserted. The holder 38 and the nozzle pedestal 36 are arranged in the first retainer cap 4. A male screw portion 311 is provided on the outer peripheral surface of the holder 38. A female screw portion 42 is provided on the inner peripheral surface of the base end portion of the first retainer cap 4. The first retainer cap 4 is attached to the torch body 3 by screwing the male screw portion 311 of the holder 38 into the female screw portion 42 of the first retainer cap 4.

The second retainer cap 5 has a cylindrical shape with a tapered tip. The tip of the second retainer cap 5 has an opening 51 into which the shield cap 10 is inserted. The second retainer cap 5 is attached to the first retainer cap 4 so as to cover the first retainer cap 4. The first retainer cap 4 is arranged in the second retainer cap 5. The first retainer cap 4 and the second retainer cap 5 hold and sandwich the replacement part unit 2a. An O-ring R1 is arranged on the outer peripheral surface of the first retainer cap 4. A male screw 401 is provided on the outer peripheral surface of the first retainer cap 4, and a female screw 501 is provided on the inner peripheral surface of the second retainer cap 5. The second retainer cap 5 is attached to the first retainer cap 4 by screwing the male screw 401 of the first retainer cap 4 and the female screw 501 of the second retainer cap 5.
1.2 Configuration of the replacement component unit Next, the replacement component unit 2a will be described. FIG. 3 is a side view of the replacement part unit 2a. FIG. 4 is a cross-sectional view taken along the central axis of the replacement component unit 2a.

As shown in FIGS. 3 and 4, the replacement component unit 2a has an electrode 6, an insulating guide 7, a nozzle 8, an insulating ring 9, and a shield cap 10 integrated by press fitting. The electrode 6, the insulating guide 7, the nozzle 8, the insulating ring 9, and the shield cap 10 are arranged concentrically with each other. Since the replacement component unit 2a is arranged concentrically with the central axis of the torch body 3, the axes of the electrode 6, the insulation guide 7, the nozzle 8, the insulation ring 9, and the shield cap 10 are the axes of the torch body 3. Aligns with the central axis.

5 and 6 are perspective views of the electrode 6. FIG. 7 is a cross-sectional view of the electrode 6. As shown in FIGS. 5 to 6, the electrode 6 has a cylindrical shape. The electrode 6 is made of a conductor. The electrode 6 has an electrode body portion 61, a joint portion 62, and a flange portion 63.

The electrode body 61 includes the tip of the electrode 6. A heat-resistant insert 64 is embedded in the center of the tip surface 602 of the electrode 6. In this embodiment, the heat resistant insert 64 is made of, for example, hafnium. However, an electrode material other than hafnium may be used as the heat-resistant insert 64. As shown in FIG. 4, a part of the electrode main body 61 is arranged in the hole of the insulating guide 7. The tip of the electrode body 61 projects from the insulation guide 7. The tip of the electrode body 61 has a tapered shape.

The joint portion 62 is located on the proximal end side of the electrode main body portion 61. The joint portion 62 is located between the electrode main body portion 61 and the flange portion 63 in the axial direction of the electrode 6. The joint portion 62 is joined to the insulating guide 7 by press fitting. Therefore, the joint 62 is joined to the insulating guide 7 so as to seal the fluid without an O-ring.

The outer peripheral surface of the joint portion 62 has an uneven shape that engages with the inner peripheral surface of the insulating guide 7. Specifically, the joint 62 has a convex 621. The convex portion 621 protrudes from the outer peripheral surface of the joint portion 62. The convex portion 621 extends in the circumferential direction of the joint portion 62.

The flange portion 63 is located on the proximal end side of the joint portion 62. The flange portion 63 includes the base end of the electrode 6. The flange portion 63 has a larger outer diameter than the joint portion 62. The flange portion 63 is longer than the joint portion 62 in the axial direction of the electrode 6. The outer peripheral surface of the flange portion 63 extends in the axial direction of the electrode 6. The outer peripheral surface of the flange portion 63 has a flat shape with no unevenness in a cross-sectional view. The base end of the outer peripheral surface of the flange portion 63 is chamfered. A step portion 66 is provided between the flange portion 63 and the joint portion 62. The step portion 66 is a plane perpendicular to the axial direction of the electrode 6.

The electrode 6 has an internal passage 65. The center pipe 20 shown in FIG. 1 is inserted into the internal passage 65. The base end surface 601 of the electrode 6 is provided with an inlet of the internal passage 65. The internal passage 65 extends from the base end surface 601 of the electrode 6 toward the tip end along the axial direction of the electrode 6. A convex portion 67 is provided on the internal passage 65 side of the tip of the electrode 6. The heat-resistant insert 64 described above is arranged in the convex portion 67. With the replacement part unit 2a attached to the torch body 3, a part of the convex portion 67 is arranged in the cooling water channel of the center pipe 20.

The inner peripheral surface of the inner passage 65 has a straight portion 651 and a tapered portion 652. The straight line portion 651 extends parallel to the axial direction of the electrode 6. The tapered portion 652 expands radially toward the entrance of the internal passage 65.

Next, the insulation guide 7 will be described. 8 and 9 are perspective views of the insulation guide 7. FIG. 10 is a cross-sectional view of the insulation guide 7. The insulation guide 7 electrically insulates the electrode 6 and the nozzle 8 and connects the electrode 6 and the nozzle 8. The insulation guide 7 positions the electrode 6 and the nozzle 8 with each other in the axial direction and the radial direction.

The insulating guide 7 has a tubular shape. The insulation guide 7 is made of an insulator. The insulation guide 7 has a hole 706 into which the electrode 6 is inserted. The hole 706 of the insulation guide 7 penetrates the insulation guide 7 in the axial direction of the insulation guide 7.

The insulating guide 7 is made of a material having an elastic modulus smaller than that of ceramic. In the present embodiment, the insulation guide 7 is made of a resin such as engineering plastic. Specifically, the insulation guide 7 is made of a resin having a continuous use temperature of 100 ° C. or higher. Further, the continuous use temperature is preferably 300 ° C. or lower. However, the insulating guide 7 may be made of a material other than resin.

As shown in FIG. 10, the inner peripheral surface of the insulating guide 7 has a first inner peripheral surface 71, an inner step portion 72, and a second inner peripheral surface 73. The first inner peripheral surface 71 extends in the axial direction of the insulating guide 7 and reaches the tip surface 701 of the insulating guide 7. The first inner peripheral surface 71 has a larger inner diameter than the second inner peripheral surface 73. The first inner peripheral surface 71 faces the outer peripheral surface of the electrode main body 61 with a gap. As will be described later, the first inner peripheral surface 71 forms a gas passage between the first inner peripheral surface 71 and the outer peripheral surface of the electrode main body 61. The inner diameter of the first inner peripheral surface 71 is substantially the same as the inner diameter of the nozzle 8. Therefore, the inner diameter of the gas passage between the first inner peripheral surface 71 and the electrode 6 is substantially the same as the inner diameter of the nozzle 8, and the inner step portion 72 is located on the proximal end side of the first inner peripheral surface 71. The inner step portion 72 is located between the first inner peripheral surface 71 and the second inner peripheral surface 73 in the axial direction of the insulating guide 7. The inner step portion 72 is inclined with respect to the axial direction of the insulating guide 7 so as to expand in the radial direction toward the tip side.

A heat-resistant coating 707 is formed on the first inner peripheral surface 71 and the inner step portion 72. The heat-resistant coating 707 is made of a ceramic material. The heat-resistant coating 707 is formed of, for example, boron nitride. However, the heat-resistant coating 707 may be formed of a ceramic material other than boron nitride. Alternatively, the heat-resistant coating 707 may be formed of a heat-resistant material other than the ceramic-based material. Alternatively, the heat-resistant coating 707 may be omitted.

The second inner peripheral surface 73 is located on the proximal end side of the inner step portion 72. The second inner peripheral surface 73 extends in the axial direction of the insulating guide 7 and reaches the base end surface 702 of the insulating guide 7. The second inner peripheral surface 73 has a first joint portion 74. The first joint portion 74 is joined to the joint portion 62 of the electrode 6 by press fitting. Therefore, the first joint portion 74 of the insulation guide 7 is joined to the electrode 6 so as to seal the fluid without the O-ring.

As shown in FIG. 4, the first joint portion 74 of the insulation guide 7 is joined to the joint portion 62 of the electrode 6, so that the electrode 6 and the insulation guide 7 are positioned with each other in the radial direction. Further, the base end surface 702 of the insulating guide 7 comes into contact with the stepped portion 66 of the flange portion 63 of the electrode 6, so that the electrode 6 and the insulating guide 7 are positioned with each other in the axial direction.

The first joint portion 74 has an uneven shape that is locked to the outer peripheral surface of the electrode 6. Specifically, the first joint 74 has a convex portion 741. The convex portion 741 protrudes from the second inner peripheral surface 73. The convex portion 741 extends in the circumferential direction of the second inner peripheral surface 73. The convex portion 741 of the first joint portion 74 of the insulation guide 7 is locked to the convex portion 621 of the joint portion 62 of the electrode 6. As a result, the insulating guide 7 is firmly prevented from coming off with respect to the electrode 6.

The outer peripheral surface of the insulating guide 7 has a first outer peripheral surface 75, a second outer peripheral surface 76, and a third outer peripheral surface 77. The first outer peripheral surface 75 extends in the axial direction of the insulating guide 7 and reaches the tip surface 701 of the insulating guide 7. The first outer peripheral surface 75 is arranged in the first hole 811 of the nozzle 8. The first outer peripheral surface 75 has a second joint portion 78. The second joint portion 78 is joined to the inner peripheral surface of the nozzle 8 by press fitting. Therefore, the second joint 78 of the insulation guide 7 is joined to the nozzle 8 so as to seal the fluid without the O-ring.

The second joint portion 78 of the insulation guide 7 has an uneven shape that locks on the inner peripheral surface of the nozzle 8. Specifically, the second joint 78 of the insulation guide 7 has a convex 781. The convex portion 781 projects from the first outer peripheral surface 75. The convex portion 781 extends in the circumferential direction of the first outer peripheral surface 75.

The second outer peripheral surface 76 is located on the proximal end side of the first outer peripheral surface 75. The second outer peripheral surface 76 extends in the axial direction of the insulating guide 7. The second outer peripheral surface 76 has a flat shape with no unevenness in a cross-sectional view. The second outer peripheral surface 76 is arranged between the first outer peripheral surface 75 and the third outer peripheral surface 77 in the axial direction of the insulating guide 7. The second outer peripheral surface 76 is arranged outside the nozzle 8. The second outer peripheral surface 76 has an outer diameter smaller than that of the first outer peripheral surface 75. In other words, the outer diameter of the first outer peripheral surface 75 is larger than the outer diameter of the second outer peripheral surface 76. In the axial direction of the insulation guide 7, the first outer peripheral surface 75 is shorter than the second outer peripheral surface 76.

The third outer peripheral surface 77 is located on the proximal end side of the second outer peripheral surface 76. The third outer peripheral surface 77 has an outer diameter smaller than that of the second outer peripheral surface 76. The third outer peripheral surface 77 extends in the axial direction of the insulating guide 7 and reaches the base end surface 702 of the insulating guide 7. In the axial direction of the insulation guide 7, the second outer peripheral surface 76 is longer than the third outer peripheral surface 77. In other words, the third outer peripheral surface 77 is shorter than the second outer peripheral surface 76 in the axial direction of the insulation guide 7. In the axial direction of the insulation guide 7, the third outer peripheral surface 77 is shorter than the first outer peripheral surface 75.

The outer peripheral surface of the insulation guide 7 has an outer step portion 79. The outer step portion 79 is arranged between the second outer peripheral surface 76 and the third outer peripheral surface 77. The outer step portion 79 is a surface perpendicular to the axial direction of the insulating guide 7.

FIG. 11 is a view of the insulation guide 7 as viewed from the base end side. As shown in FIGS. 9 and 11, the insulating guide 7 has a plurality of communication passages 703. In this embodiment, the insulation guide 7 has six communication passages 703. However, the number of communication passages 703 is not limited to 6, and may be less than 6 or more than 6.

FIG. 12 shows a cross section of the insulating guide 7 including the axis of one communication passage 703. As shown in FIG. 12, the communication passage 703 communicates the outside of the insulation guide 7 with the inside of the hole 706 of the insulation guide 7. In other words, the communication passage 703 communicates the outside of the insulation guide 7 with the gas passage inside the insulation guide 7. The communication passage 703 extends in a direction inclined with respect to the axial direction. The communication passage 703 is inclined toward the tip of the insulating guide 7 so as to approach the axis of the insulating guide 7. The inclination angle of the communication passage 703 with respect to the axial direction of the insulation guide 7 is preferably 30 degrees or more and 60 degrees or less. For example, the inclination angle of the communication passage 703 with respect to the axial direction of the insulation guide 7 is 45 degrees.

One end of the communication passage 703 is connected to the inner step portion 72. The other end of the communication passage 703 is connected to the outer step portion 79. The communication passage 703 is connected to the outer peripheral surface of the insulation guide 7 at a position closer to the base end side than the center in the axial direction of the insulation guide 7. The communication passage 703 connects the first communication passage 704 and the second communication passage 705. Have.

The first passage 704 has a larger flow path cross section than the second passage 705. The first passage 704 is connected to the outer step portion 79. The first communication passage 704 communicates with the outside of the insulation guide 7. The second passage 705 is connected to the inner step portion 72. The second communication passage 705 communicates with the gas passage in the insulation guide 7. Although only one communication passage 703 is shown in FIG. 12, the other communication passages 703 have the same structure as the communication passage 703 in FIG.

As shown in FIG. 11, the plurality of communication passages 703 are inclined with respect to the circumferential direction and the radial direction. All passages 703 are inclined in the same direction with respect to the circumferential direction. All passages 703 are inclined in the same direction with respect to the radial direction. As a result, the gas blown out from the communication passage 703 becomes a swirling flow. The plurality of communication passages 703 are arranged at equal intervals in the circumferential direction of the insulating guide 7. When viewed from the axial direction of the insulating guide 7, the axis of the communication passage 703 is parallel to the axis of the communication passage 703 and is separated from the straight line passing through the center of the insulation guide 7 by a predetermined distance.

Next, the nozzle 8 will be described. 13 and 14 are perspective views of the nozzle 8. FIG. 15 is a cross-sectional view of the nozzle 8. The nozzle 8 has a cylindrical shape with a tapered tip. The nozzle 8 has a hole 811 into which the insulating guide 7 is inserted, and is joined to the insulating guide 7 by press fitting. Specifically, the nozzle 8 has a first nozzle portion 81, a second nozzle portion 82, and a third nozzle portion 83.

The first nozzle portion 81 includes the base end of the nozzle 8. The first nozzle portion 81 has a first hole 811. The second nozzle portion 82 is located on the tip end side of the first nozzle portion 81. The second nozzle portion 82 is located between the first nozzle portion 81 and the third nozzle portion 83 in the axial direction of the nozzle 8. In the axial direction of the nozzle 8, the second nozzle portion 82 is longer than the first nozzle portion 81.

The second nozzle portion 82 has a second hole 821 that communicates with the first hole 811. The second hole 821 has an inner diameter smaller than that of the first hole 811. Therefore, an inner step portion 84 is provided between the inner peripheral surface 812 of the first nozzle portion 81 and the inner peripheral surface 822 of the second nozzle portion 82. The inner step portion 84 is a surface perpendicular to the axial direction of the nozzle 8.

The outer diameter of the second nozzle portion 82 is the same as the outer diameter of the first nozzle portion 81. Therefore, the outer peripheral surface 823 of the second nozzle portion 82 is flush with the outer peripheral surface 813 of the first nozzle portion 81. The base end of the outer peripheral surface 813 of the first nozzle portion 81 is chamfered. The second nozzle portion 82 has a larger radial thickness than the first nozzle portion 81.

The third nozzle portion 83 includes the tip of the nozzle 8. The third nozzle portion 83 is located on the tip end side of the second nozzle portion 82. The third nozzle portion 83 has an injection hole 831. The injection hole 831 has an inner diameter smaller than that of the second hole 821. The injection hole 831 extends in the axial direction of the nozzle 8 and reaches the tip surface 801 of the nozzle 8. In the axial direction of the nozzle 8, the first hole 811 described above is shorter than the injection hole 831.

The injection hole 831 communicates with the second hole 821 via the tapered hole 832. The tapered hole 832 is located between the injection hole 831 and the second hole 821 in the axial direction of the nozzle 8, and connects the injection hole 831 and the second hole 821. The tapered hole 832 becomes smaller in the radial direction toward the tip of the nozzle 8.

The outer peripheral surface of the nozzle 8 has a first outer peripheral surface 85, a second outer peripheral surface 86, and a third outer peripheral surface 87. The first outer peripheral surface 85 reaches the base end surface 802 of the nozzle 8. The first outer peripheral surface 85 is composed of an outer peripheral surface 813 of the first nozzle portion 81 and an outer peripheral surface 823 of the second nozzle portion 82. The first outer peripheral surface 85 has a linear shape extending in the axial direction of the nozzle 8 in a cross-sectional view. In other words, the first outer peripheral surface 85 has a flat shape without unevenness in a cross-sectional view.

The second outer peripheral surface 86 is located on the tip end side of the first outer peripheral surface 85. The second outer peripheral surface 86 is located between the first outer peripheral surface 85 and the third outer peripheral surface 87 in the axial direction of the nozzle 8. The second outer peripheral surface 86 has an outer diameter smaller than that of the first outer peripheral surface 85. Therefore, an outer step portion 88 is provided between the first outer peripheral surface 85 and the second outer peripheral surface 86. The outer step portion 88 is a surface perpendicular to the axial direction of the nozzle 8.

The third outer peripheral surface 87 is located on the tip end side of the second outer peripheral surface 86. The third outer peripheral surface 87 reaches the tip surface 801 of the nozzle 8. The third outer peripheral surface 87 is inclined so as to be smaller in the radial direction toward the tip end.

The insulation guide 7 is inserted into the first hole 811 of the first nozzle portion 81. The electrode 6 is inserted into the second hole 821 of the second nozzle portion 82. As shown in FIG. 4, the inner peripheral surface 822 of the second nozzle portion 82 faces the electrode main body portion 61 with a gap. The tip of the electrode 6 faces the tapered hole 832 of the third nozzle portion 83.

The first nozzle portion 81 is joined to the insulating guide 7. Specifically, the second joint portion 78 of the insulating guide 7 is inserted into the first hole 811, and the first nozzle portion 81 is joined to the second joint portion 78 of the insulating guide 7 by press fitting. As a result, the inner peripheral surface 812 of the first nozzle portion 81 is joined to the insulating guide 7 so as to seal the fluid without the O-ring.

By joining the inner peripheral surface 812 of the first nozzle portion 81 to the second joint portion 78 of the insulating guide 7, the nozzle 8 and the insulating guide 7 are positioned with each other in the radial direction. Further, when the tip surface 701 of the insulating guide 7 comes into contact with the inner step portion 84 of the nozzle 8, the nozzle 8 and the insulating guide 7 are positioned with each other in the axial direction.

The inner peripheral surface 812 of the first nozzle portion 81 has an uneven shape that is locked to the outer peripheral surface of the insulating guide 7. Specifically, the inner peripheral surface 812 of the first nozzle portion 81 has a convex portion 814. The convex portion 814 of the first nozzle portion 81 is locked to the convex portion 781 of the second joint portion 78 of the insulating guide 7. As a result, the nozzle 8 is prevented from coming off with respect to the insulating guide 7.

The second outer peripheral surface 86 has an uneven shape that locks to the inner peripheral surface of the insulating ring 9. Specifically, the second outer peripheral surface 86 has a convex portion 861.

16 and 17 are perspective views of the insulating ring 9. FIG. 18 is a cross-sectional view of the insulating ring 9. As shown in FIGS. 16-18, the insulating ring 9 has a hole 903 into which the nozzle 8 is inserted. The inner peripheral surface 91 of the insulating ring 9 has a convex portion 911. The outer peripheral surface 92 of the insulating ring 9 has a convex portion 921.

The insulating ring 9 has a flange portion 93. The flange portion 93 projects from the outer peripheral surface 92 of the insulating ring 9. Therefore, a step portion 94 is provided between the outer peripheral surface 92 of the insulating ring 9 and the flange portion 93. The step portion 94 is a surface perpendicular to the axial direction of the insulating ring 9.

As shown in FIG. 4, the insulating ring 9 is joined to the nozzle 8 by press fitting. Specifically, the inner peripheral surface 91 of the insulating ring 9 is joined to the second outer peripheral surface 86 of the nozzle 8 by press fitting. By joining the inner peripheral surface 91 of the insulating ring 9 to the second outer peripheral surface 86 of the nozzle 8, the insulating ring 9 and the nozzle 8 are positioned with each other in the radial direction.

Further, when the base end surface 901 of the insulating ring 9 comes into contact with the outer end portion 88 of the nozzle 8, the insulating ring 9 and the nozzle 8 are positioned with each other in the axial direction. The convex portion 911 of the inner peripheral surface 91 of the insulating ring 9 is locked to the convex portion 861 of the second outer peripheral surface 86 of the nozzle 8. As a result, the insulating ring 9 is firmly prevented from coming off with respect to the nozzle 8.

19 and 20 are perspective views of the shield cap 10. FIG. 21 is a cross-sectional view of the shield cap 10. As shown in FIGS. 19 to 21, the shield cap 10 has a hole 103. The nozzle 8 is inserted into the hole 103 of the shield cap 10. The shield cap 10 has an injection hole 104. The injection hole 104 communicates with the hole 103 and penetrates the tip surface 101 of the shield cap 10 in the axial direction.

The shield cap 10 has a first inner peripheral surface 11 and a second inner peripheral surface 12. The first inner peripheral surface 11 extends in the axial direction of the shield cap 10 and reaches the base end surface 102 of the shield cap 10. The first inner peripheral surface 11 has a convex portion 111. The second inner peripheral surface 12 is located on the tip end side of the first inner peripheral surface 11. The second inner peripheral surface 12 is inclined so as to be smaller in the radial direction toward the tip end.

The shield cap 10 has a first outer peripheral surface 13, a flange portion 14, a second outer peripheral surface 15, and a third outer peripheral surface 16. The first outer peripheral surface 13 extends in the axial direction of the shield cap 10 and reaches the base end surface 102 of the shield cap 10. The flange portion 14 is located on the tip end side of the first outer peripheral surface 13. The flange portion 14 is located between the first outer peripheral surface 13 and the second outer peripheral surface 15 in the axial direction of the shield cap 10. The flange portion 14 projects from the first outer peripheral surface 13. The flange portion 14 projects from the second outer peripheral surface 15. An outer step portion 17 is provided between the flange portion 14 and the second outer peripheral surface 15. The outer step portion 17 is a surface perpendicular to the axial direction of the shield cap 10. The outer diameter of the flange portion 14 is larger than the diameter of the opening 41 of the first retainer cap 4. The outer diameter of the flange portion 14 is larger than the diameter of the opening 51 of the second retainer cap 5.

The second outer peripheral surface 15 is located on the tip end side of the flange portion 14. The second outer peripheral surface 15 has an outer diameter smaller than that of the first outer peripheral surface 13. The second outer peripheral surface 15 extends in the axial direction of the shield cap 10. The third outer peripheral surface 16 is located on the tip end side of the second outer peripheral surface 15. The third outer peripheral surface 16 reaches the tip surface 101 of the shield cap 10. The third outer peripheral surface 16 is inclined with respect to the axial direction of the shield cap 10 so as to decrease in the radial direction toward the tip end.

FIG. 22 is a cross-sectional view taken along the line AA of FIG. As shown in FIGS. 21 and 22, the shield cap 10 has a plurality of communication passages 105. The communication passage 105 communicates the outside of the shield cap 10 with the inside of the hole 103 of the shield cap 10. One end of the communication passage 105 reaches the first outer peripheral surface 13. The other end of the communication passage 105 reaches the first inner peripheral surface 11.

The communication passages 105 are arranged at equal intervals in the circumferential direction of the shield cap 10. When viewed from the axial direction of the shield cap 10, the axis of the communication passage 105 is parallel to the axis of the communication passage 105 and is separated from the straight line passing through the center of the insulation guide 7 by a predetermined distance. All the passages 105 are inclined in the same direction with respect to the circumferential direction. All passages 105 are inclined in the same direction with respect to the radial direction. As a result, the gas blown out from the communication passage 105 becomes a swirling flow.

As shown in FIG. 4, the shield cap 10 is joined to the insulating ring 9 by press fitting. Specifically, the first inner peripheral surface 11 of the shield cap 10 is joined to the outer peripheral surface 92 of the insulating ring 9 by press fitting. The convex portion 111 of the first inner peripheral surface 11 of the shield cap 10 engages with the convex portion 921 of the outer peripheral surface 92 of the insulating ring 9. As a result, the shield cap 10 is firmly prevented from coming off from the insulating ring 9.

By joining the first inner peripheral surface 11 of the shield cap 10 to the outer peripheral surface 92 of the insulating ring 9, the shield cap 10 and the insulating ring 9 are positioned with each other in the radial direction. As a result, the injection holes 104 of the shield cap 10 and the injection holes 831 of the nozzle 8 are arranged concentrically.

When the base end surface 102 of the shield cap 10 comes into contact with the stepped portion 94 of the insulating ring 9, the shield cap 10 and the insulating ring 9 are positioned with each other in the axial direction. As a result, the shield cap 10 is arranged with respect to the nozzle 8 with a gap. Specifically, the second inner peripheral surface 12 of the shield cap 10 is arranged with a gap from the third outer peripheral surface 87 of the nozzle 8. As a result, a gas passage described later is formed between the shield cap 10 and the nozzle 8. The communication passage 105 of the shield cap 10 is located on the tip side of the tip of the insulating ring 9. The communication passage 105 of the shield cap 10 communicates with the gas passage between the shield cap 10 and the nozzle 8.

Next, the center pipe 20 will be described. 23 and 24 are perspective views of the center pipe 20. FIG. 25 is a cross-sectional view of the center pipe 20. The center pipe 20 is inserted into the internal passage 65 of the electrode 6 and supplies cooling water into the electrode 6. The center pipe 20 is made of a conductor. The center pipe 20 has a pipe body 21 and a contactor 22. FIG. 26 is a perspective view of the pipe body 21. FIG. 27 is a perspective view of the contactor 22.

The pipe body 21 has a tubular shape. The pipe body 21 is made of a conductor. Specifically, the outer peripheral surface of the pipe body 21 has a flange portion 23, a first outer peripheral surface 24, a second outer peripheral surface 25, and a third outer peripheral surface 26. The flange portion 23 includes the base end of the pipe body 21. The flange portion 23 projects from the first outer peripheral surface 24. Therefore, a step portion 27 is provided between the flange portion 23 and the first outer peripheral surface 24. The step portion 27 is a surface perpendicular to the axial direction of the pipe body 21.

The first outer peripheral surface 24 is located on the tip end side of the flange portion 23. The first outer peripheral surface 24 is located between the flange portion 23 and the second outer peripheral surface 25 in the axial direction of the pipe body 21. The first outer peripheral surface 24 extends in the axial direction of the pipe body 21.

The second outer peripheral surface 25 is located on the tip end side of the first outer peripheral surface 24. The second outer peripheral surface 25 is located between the first outer peripheral surface 24 and the third outer peripheral surface 26 in the axial direction of the pipe body 21. The second outer peripheral surface 25 extends in the axial direction of the pipe body 21. In the axial direction of the pipe body 21, the second outer peripheral surface 25 is shorter than the first outer peripheral surface 24. The second outer peripheral surface 25 has an outer diameter smaller than that of the first outer peripheral surface 24.

The third outer peripheral surface 26 is located on the tip end side of the second outer peripheral surface 25. The third outer peripheral surface 26 includes the tip of the pipe body 21. The third outer peripheral surface 26 extends in the axial direction of the pipe body 21. The third outer peripheral surface 26 is longer than the first outer peripheral surface 24 in the axial direction of the pipe body 21. The third outer peripheral surface 26 has an outer diameter smaller than that of the second outer peripheral surface 25. A recess 261 is provided in the middle portion of the third outer peripheral surface 26 in the axial direction. A contactor 22 is attached to the recess 261.

The pipe body 21 has a cooling water passage inside. The cooling water passage penetrates the pipe body 21 in the axial direction. The cooling water passage has a first passage 211, a second passage 212, and a third passage 231. The first passage 211 reaches the base end surface 201 of the pipe body 21. The first passage 211 is inclined with respect to the axial direction of the pipe body 21 so as to decrease in the radial direction toward the tip.

The second passage 212 is located on the tip end side of the first passage 211. The second passage 212 is located between the first passage 211 and the third passage 231 in the axial direction of the pipe body 21. In the axial direction of the pipe body 21, the second passage 212 is longer than the third passage 231. The second passage 212 extends in the axial direction of the pipe body 21.

The third passage 231 is located on the tip end side of the second passage 212. The third passage 231 reaches the tip surface 202 of the pipe body 21. The third passage 231 has a larger inner diameter than the second passage 212. The convex portion 67 of the electrode 6 described above is arranged in the third passage 231.

The contactor 22 is separate from the pipe body 21. The contactor 22 is made of a conductor. The contactor 22 is detachably attached to the pipe body 21. The contactor 22 is attached to the outer peripheral surface of the pipe body 21. Specifically, the contactor 22 is attached to the pipe body 21 by being fitted into the recess 261 of the third outer peripheral surface 26 of the pipe body 21.

The contactor 22 has a mounting portion 28 and a contact portion 29. The mounting portion 28 is mounted on the outer peripheral surface of the pipe body 21. The mounting portion 28 has a first ring portion 281 and a second ring portion 282. The second ring portion 282 is arranged away from the first ring portion 281 in the axial direction of the contact 22. The first ring portion 281 and the second ring portion 282 are fitted into the recesses 261 of the pipe body 21, respectively.

The contact portion 29 contacts the inner peripheral surface of the electrode 6. The contact portion 29 has elasticity so as to generate a reaction force when pressed in the radial direction of the contactor 22. Specifically, the contact portion 29 has a plurality of curved portions 291. The curved portion 291 connects the first ring portion 281 and the second ring portion 282. The curved portion 291 has a plate-like shape that bulges outward in the radial direction of the contact 22. The contact portion 29 has a plurality of slits 292. The slit 292 is provided between the plurality of curved portions 291 and extends in the axial direction of the contactor 22. In the drawings, reference numeral 292 is attached only to a part of the slit 292, and the reference numerals of the other slits 292 are omitted.

FIG. 28 is a view of the contactor 22 as viewed from the axial direction. As shown in FIG. 28, the plurality of curved portions 291 are arranged at equal intervals in the circumferential direction of the contactor 22. Similarly, the plurality of slits 292 are also arranged at equal intervals in the circumferential direction of the contactor 22. In this embodiment, the contactor 22 has eight curved portions 291 and eight slits 292. However, the number of contacts 22 is not limited to eight and may be less than eight or more than eight. Similarly, the number of slits 292 is not limited to eight, and may be less than eight or more than eight.

As shown in FIG. 1, the flange portion 23 of the center pipe 20 is arranged between the base end surface 341 of the electrode pedestal 34 and the bottom surface 331 of the hole of the base portion 33. The flange portion 23 is in contact with the base end surface 341 of the electrode pedestal 34. As a result, the center pipe 20 and the electrode pedestal 34 are electrically connected. Further, the center pipe 20 is positioned in the radial direction and the axial direction.

FIG. 29 is an enlarged view of the configuration of the replacement part unit 2a and its surroundings in FIG. As shown in FIG. 29, the contactor 22 of the center pipe 20 is in contact with the inner peripheral surface of the electrode 6. The contactor 22 is elastically deformed inward in the radial direction by being inserted into the internal passage 65 of the electrode 6. The contactor 22 is pressed against the inner peripheral surface of the electrode 6 by the reaction force of elastic deformation. The center pipe 20 is electrically connected to the electrode pedestal 34. Therefore, the contactor 22 energizes the electrode 6 by contacting the inner peripheral surface of the electrode 6.

The electrode 6 has a first energizing surface 603 and a second energizing surface 601. The first energizing surface 603 is a portion of the inner peripheral surface of the internal passage 65 that is in contact with the contactor 22. The electrode 6 is electrically connected to the electrode pedestal 34 via the center pipe 20 and the first energizing surface 603. The first energizing surface 603 is arranged adjacent to the tapered portion 652 on the tip end side of the tapered portion 652. The first energizing surface 603 is located in the cooling water passage described later.

The second energizing surface 601 is the base end surface 601 of the electrode 6. The second energizing surface 601 is in contact with the tip surface 342 of the electrode pedestal 34. The electrode 6 is electrically connected to the electrode pedestal 34 via the second energizing surface 601. The second energizing surface 601 is adjacent to the cooling water passage described later.
1.3 Cooling water passage Next, the cooling water passage of the plasma torch 1a will be described. In FIG. 1, the solid arrow indicates the flow of cooling water. As shown in FIG. 1, a cooling water supply pipe 45 is connected to the base portion 33. The cooling water supply pipe 45 is connected to the second cooling water passage W2 in the nozzle pedestal 36 via the first cooling water passage W1 in the base portion 33. The first cooling water passage W1 extends from the base end surface of the base portion 33 toward the outer peripheral surface of the base portion 33. The second cooling water passage W2 extends from the inner peripheral surface of the nozzle pedestal 36 toward the tip of the nozzle pedestal 36. The second cooling water passage W2 is connected to the third cooling water passage W3. The third cooling water passage W3 is an annular passage surrounded by the nozzle pedestal 36, the first retainer cap 4, and the replacement part unit 2a.

As shown in FIG. 29, a gap is provided between the tip surface 371 of the insulating sleeve 37 and the base end surface 802 of the nozzle 8, and this gap constitutes a part of the third cooling water passage W3. There is. Therefore, the base end surface 802 of the nozzle 8 is arranged in the third cooling water passage W3. Further, the gap between the tip surface 371 of the insulating sleeve 37 and the base end surface 802 of the nozzle 8 reaches the second outer peripheral surface 76 of the insulating guide 7. Therefore, a part of the second outer peripheral surface 76 of the insulation guide 7 is arranged in the third cooling water passage W3.

As shown in FIG. 1, the third cooling water passage W3 is included in the fourth cooling water passage W4 in the nozzle pedestal 36, the fifth cooling water passage W5 between the nozzle pedestal 36 and the insulating sleeve 37, and the insulating sleeve 37. It is connected to the eighth cooling water passage W8 via the sixth cooling water passage W6 and the seventh cooling water passage W7 in the electrode pedestal 34.

The fourth cooling water passage W4 extends from the tip of the nozzle pedestal 36 toward the inner peripheral surface of the nozzle pedestal 36. The fifth cooling water passage W5 is an annular passage provided between the nozzle pedestal 36 and the insulating sleeve 37. The sixth cooling water passage W6 is a plurality of passages extending in the radial direction from the outer peripheral surface of the insulating sleeve 37 toward the inner peripheral surface of the insulating sleeve 37. The seventh cooling water passage W7 is a plurality of passages extending in the radial direction from the outer peripheral surface of the electrode pedestal 34 toward the inner peripheral surface of the electrode pedestal 34. The eighth cooling water passage W8 is a passage between the electrode pedestal 34 and the center pipe 20.

The eighth cooling water passage W8 is connected to the ninth cooling water passage W9 between the electrode 6 and the center pipe 20. The ninth cooling water passage W9 communicates with the tenth cooling water passage W10 in the center pipe 20 at the tip end portion of the center pipe 20. The tenth cooling water passage W10 is connected to the cooling water discharge pipe 46 via the eleventh cooling water passage W11 in the base portion 33.

The cooling water flows from the cooling water supply source through the cooling water supply pipe 45, the first cooling water passage W1 in the base 33, the second cooling water passage W2 in the nozzle pedestal 36, and the third cooling water passage W3. Is supplied to. The cooling water is from the third cooling water passage W3 to the fourth cooling water passage W4 in the nozzle pedestal 36, the fifth cooling water passage W5 between the nozzle pedestal 36 and the insulating sleeve 37, and the sixth cooling water in the insulating sleeve 37. It is supplied to the eighth cooling water passage W8 between the electrode pedestal 34 and the center pipe 20 through the passage W6 and the seventh cooling water passage W7 in the electrode pedestal 34. The cooling water is from the eighth cooling water passage W8, the ninth cooling water passage W9 between the electrode 6 and the center pipe 20, the tenth cooling water passage W10 in the center pipe 20, and the eleventh cooling water in the base portion 33. It is discharged to the outside of the plasma torch 1a through the passage W11 and the cooling water discharge pipe 46.
1.4 Gas passage Next, the plasma gas passage of the plasma torch 1a will be described. In this embodiment, the plasma gas is oxygen gas. However, other gases such as argon or nitrogen may be used. FIG. 30 is a cross-sectional view different from FIG. 1 along the central axis of the plasma torch 1a. In FIGS. 1 and 30, the dashed arrow indicates the flow of plasma gas. Specifically, the dashed arrow in FIG. 30 indicates the flow of the main gas. In FIG. 1, the broken line arrow indicates the flow of the assist gas.

As shown in FIG. 30, a main gas supply pipe 47 is connected to the base portion 33. The main gas supply pipe 47 is connected to the second main gas passage MG2 between the base portion 33 and the insulating sleeve 37 via the first main gas passage MG1 in the base portion 33. The first main gas passage MG1 extends in the axial direction from the base end surface of the base portion 33 toward the step portion 332 of the inner peripheral surface of the base portion 33. The second main gas passage MG2 is an annular passage formed between the step portion 332 on the inner peripheral surface of the base portion 33 and the step portion 372 on the outer peripheral surface of the insulating sleeve 37.

The second main gas passage MG2 is connected to the fourth main gas passage MG4 via the third main gas passage MG3 in the insulating sleeve 37. The third main gas passage MG3 extends in the axial direction from the step portion 372 on the outer peripheral surface of the insulating sleeve 37. The fourth main gas passage MG4 is an annular passage between the insulating sleeve 37 and the replacement part unit 2a.

FIG. 31 is an enlarged view of the configuration of the replacement part unit 2a and its surroundings in FIG. 30. As shown in FIG. 31, the fourth main gas passage MG4 is composed of an inner peripheral surface of the insulating sleeve 37, an outer peripheral surface of the insulating guide 7, and an outer peripheral surface of the electrode 6.

Specifically, a step portion 373 is provided on the inner peripheral surface of the insulating sleeve 37. The step portion 373 is a surface perpendicular to the axial direction of the insulating sleeve 37. With the replacement component unit 2a attached to the torch body 3, the outer step portion 79 of the insulation guide 7 is arranged with a gap from the step portion 373 on the inner peripheral surface of the insulation sleeve 37. The fourth main gas passage MG4 passes through a gap between the outer step portion 79 of the insulating guide 7 and the step portion 373 on the inner peripheral surface of the insulating sleeve 37.

The fourth main gas passage MG4 is sealed by an O-ring R2 with respect to the above-mentioned third cooling water passage W3. The O-ring R2 is fitted in a recess 374 provided on the inner peripheral surface of the insulating sleeve 37. The O-ring R2 is in contact with a part of the second outer peripheral surface 76 of the insulating guide 7. That is, the second outer peripheral surface 76 of the insulating guide 7 has a sealing surface 761 that comes into contact with the O-ring. A portion of the second outer peripheral surface 76 on the tip side of the seal surface 761 is arranged in the third cooling water passage W3. A portion of the second outer peripheral surface 76 on the base end side of the seal surface 761 is arranged in the fourth main gas passage MG4. The third outer peripheral surface 77 is also arranged in the fourth main gas passage MG4 in the same manner as the second outer peripheral surface 76.
As shown in FIG. 29, the fourth main gas passage MG4 is sealed by the O-ring R3 with respect to the above-mentioned sixth cooling water passage W6 and the seventh cooling water passage W7. The O-ring R3 is fitted in a recess 375 provided on the inner peripheral surface of the insulating sleeve 37. The O-ring R3 is in contact with a part of the outer peripheral surface of the flange portion 63 of the electrode 6. That is, the outer peripheral surface of the flange portion 63 has a sealing surface 631 that comes into contact with the O-ring R3. A portion of the outer peripheral surface of the flange portion 63 on the tip side of the sealing surface 631 is arranged in the fourth main gas passage MG4.

As shown in FIG. 31, the fourth main gas passage MG4 is connected to the fifth main gas passage MG5 between the insulation guide 7 and the electrode 6 via a plurality of communication passages 703 of the insulation guide 7. The fifth main gas passage MG5 is an annular passage between the inner peripheral surface of the insulating guide 7 and the outer peripheral surface of the electrode 6. The fifth main gas passage MG5 is connected to the sixth main gas passage MG6 between the nozzle 8 and the electrode 6. The inner diameter of the fifth main gas passage MG5 is the same as the inner diameter of the sixth main gas passage MG6. The sixth main gas passage MG6 communicates with the injection hole 831 of the nozzle 8.

The main gas is the first main gas passage MG1 in the base portion 33, the second main gas passage MG2 between the base portion 33 and the insulating sleeve 37, and the third main gas in the insulating sleeve 37 from the main gas supply source. It flows through the passage MG3 to the fourth main gas passage MG4 between the insulating sleeve 37 and the replacement part unit 2a. The main gas becomes a swirling flow from the fourth main gas passage MG4 through the communication passage 703, and is ejected to the fifth main gas passage MG5. The swirling main gas is ejected from the injection hole 831 of the nozzle 8 through the sixth main gas passage MG6.

As shown in FIG. 1, an assist gas supply pipe 48 is connected to the base portion 33. The assist gas supply pipe 48 is connected to the second assist gas passage AG2 in the nozzle pedestal 36 via the first assist gas passage AG1 in the base portion 33. The first assist gas passage AG1 extends from the base end surface of the base portion 33 toward the outer peripheral surface of the base portion 33. The second assist gas passage AG2 extends from the inner peripheral surface of the nozzle pedestal 36 toward the outer peripheral surface of the nozzle pedestal 36.

The second assist gas passage AG2 is connected to the fourth assist gas passage AG4 between the holder 38 and the second retainer cap 5 via the third assist gas passage AG3 in the holder 38. The third assist gas passage AG3 extends from the inner peripheral surface of the holder 38 toward the outer peripheral surface. The fourth assist gas passage AG4 is an annular passage between the outer peripheral surface of the holder 38 and the inner peripheral surface of the second retainer cap 5.

The fourth assist gas passage AG4 is connected to the sixth assist gas passage AG6 between the first retainer cap 4 and the second retainer cap 5 via the fifth assist gas passage AG5 in the second retainer cap 5. .. The fifth assist gas passage AG5 is a plurality of passages extending from the inner peripheral surface of the second retainer cap 5 toward the outer peripheral surface. The sixth assist gas passage AG6 is an annular passage between the inner peripheral surface of the first retainer cap 4 and the outer peripheral surface of the second retainer cap 5.

As shown in FIG. 29, the sixth assist gas passage AG6 is connected to the seventh assist gas passage AG7 between the nozzle 8 and the shield cap 10 via a plurality of communication passages 105 of the shield cap 10. The seventh assist gas passage AG7 communicates with the injection hole 831 of the nozzle 8 and the injection hole 104 of the shield cap 10.

The sixth assist gas passage AG6 is sealed by an O-ring R4 with respect to the above-mentioned third cooling water passage W3. The O-ring R4 is fitted in a recess 44 provided at the tip of the inner peripheral surface of the first retainer cap 4. The O-ring R4 is in contact with the first outer peripheral surface 13 of the shield cap 10. That is, the first outer peripheral surface 13 of the shield cap 10 has a seal surface 131 that comes into contact with the O-ring R4.

As described above, the insulating ring 9 is joined to the nozzle 8 by press fitting. Further, the insulating ring 9 is joined to the shield cap 10 by press fitting. Therefore, the seventh assist gas passage AG7 is sealed by the insulating ring 9 with respect to the above-mentioned third cooling water passage W3.

From the assist gas supply source, the assist gas is the first assist gas passage AG1 in the base portion 33, the second assist gas passage AG2 in the nozzle pedestal 36, the third assist gas passage AG3 in the holder 38, the holder 38 and the first. The sixth assist between the first retainer cap 4 and the second retainer cap 5 through the fourth assist gas passage AG4 between the two retainer caps 5 and the fifth assist gas passage AG5 in the second retainer cap 5. It flows into the gas passage AG6. The assist gas becomes a swirling flow from the 6th assist gas passage AG6 through the communication passage 105, and is ejected into the 7th assist gas passage AG7. The swirling assist gas is ejected from the injection hole 104 of the shield cap 10 together with the main gas through the seventh assist gas passage AG7.
1.5 Replacement method of replacement component unit Next, a replacement method of the replacement component unit 2a will be described. The replacement part unit 2a is a consumable item. Therefore, the replacement part unit 2a is detachably attached to the torch body 3, and when it is consumed to the extent that it needs to be replaced, it is replaced with a new one. As shown in FIG. 29, in the plasma torch 1a, the step portion 17 of the shield cap 10 is pressed in the axial direction by the edge portion of the opening 51 of the second retainer cap 5. Further, the flange portion 14 of the shield cap 10 is sandwiched between the edge portion of the opening 41 of the first retainer cap 4 and the edge portion of the opening 51 of the second retainer cap 5. As a result, the replacement part unit 2a is fixed. Therefore, when replacing the replacement component unit 2a, the second retainer cap 5 is first removed.

When the second retainer cap 5 is removed, the replacement part unit 2a is held by the elastic force of the O-rings R2, R3, and R4. Therefore, by pulling out the replacement part unit 2a from the opening 41 of the first retainer cap 4 toward the tip side, the insulating guide 7 and the electrode 6 of the replacement part unit 2a are pulled out from the insulating sleeve 37. At that time, the contactor 22 of the center pipe 20 slides along the inner peripheral surface of the electrode 6, and the electrode 6 is pulled out from the center pipe 20.

Before pulling out the replacement part unit 2a from the opening 41 of the first retainer cap 4 toward the tip side, it is preferable to loosen the first retainer cap 4. As a result, the flange portion 14 of the shield cap 10 is caught by the edge portion of the opening 41 of the first retainer cap 4 and pushed out. As a result, the replacement part unit 2a can be easily removed.

As described above, the replacement part unit 2a can be easily and integrally removed from the torch body 3.

When installing a new replacement part unit 2a, the replacement part unit 2a is inserted from the opening 41 of the first retainer cap 4 toward the base end side. As a result, the electrode 6 of the replacement component unit 2a and the insulating guide 7 are inserted into the insulating sleeve 37. At that time, the center pipe 20 is inserted into the electrode 6, and the contactor 22 of the center pipe 20 slides along the inner peripheral surface of the electrode 6.

Then, when the second retainer cap 5 is attached to the first retainer cap 4, the edge portion of the opening 51 of the second retainer cap 5 presses the step portion 17 of the shield cap 10 toward the proximal end side. As a result, the replacement component unit 2a is pushed toward the proximal end side until the proximal end surface 601 of the electrode 6 comes into contact with the distal end surface 342 of the electrode pedestal 34. Then, the flange portion 14 of the shield cap 10 is sandwiched and held by the edge portion of the opening 41 of the first retainer cap 4 and the edge portion of the opening 51 of the second retainer cap 5, so that the replacement part unit 2a is held. It is fixed.

In the replacement component unit 2a described above, the electrode 6, the insulating guide 7, and the nozzle 8 are integrated and joined to each other so that they cannot be separated by a general user. Therefore, by replacing the replacement component unit 2a, the electrode 6, the insulating guide 7, and the nozzle 8 can be replaced at the same time. Further, since the electrode 6, the insulating guide 7, and the nozzle 8 are joined by press fitting, the electrode 6, the insulating guide 7, and the nozzle 8 can be joined without using an O-ring. As a result, the degree of concentricity between the electrode 6 and the nozzle 8 can be improved.

The flange portion 63 of the electrode 6 includes the proximal end of the electrode 6. That is, the electrode 6 does not have a portion extending toward the proximal end side from the flange portion 63. In order to provide screws and contacts on the electrode side to ensure energization between the electrode and the electrode pedestal, the conventional plasma torch has a portion where the electrode extends from the flange portion to the proximal end side. There is something that is. In this embodiment, the electrode 6 can be miniaturized as compared with the electrode of such a conventional plasma torch. Therefore, it is possible to suppress an increase in the size of the entire replacement component unit 2a including the electrode 6.

Further, in the conventional plasma torch, the portion extending toward the proximal end side of the electrode described above is an energizing surface with the electrode pedestal. The electrode 6 according to the present embodiment does not have a portion extending toward the base end side of the electrode as in the conventional case, but has a first energizing surface 603 that comes into contact with the center pipe 20 in the internal passage. Therefore, the electrode 6 can be stably energized.

In the axial direction of the electrode 6, the flange portion 63 of the electrode 6 is longer than the joint portion 62. By enlarging the flange portion 63 of the electrode 6 in the axial direction in this way, the outer peripheral surface of the flange portion 63 can be used as the sealing surface 631 in contact with the O-ring R3.

In the axial direction of the insulating guide 7, the first outer peripheral surface 75 of the insulating guide 7 is shorter than the second outer peripheral surface 76. In other words, in the axial direction of the insulating guide 7, the second outer peripheral surface 76 of the insulating guide 7 is longer than the first outer peripheral surface 75. By increasing the second outer peripheral surface 76 of the insulating guide 7 in the axial direction in this way, the second outer peripheral surface 76 of the insulating guide 7 can be used as the sealing surface 761 in contact with the O-ring R2.

Further, by using the second outer peripheral surface 76 of the insulation guide 7 as the seal surface 761, the portion of the second outer peripheral surface 76 on the tip side of the seal surface 761 can be arranged in the third cooling water passage W3. .. In this way, by arranging a part of the second outer peripheral surface 76 of the insulating guide 7 in the third cooling water passage W3, the insulating guide 7 can be effectively cooled.

In the axial direction of the nozzle 8, the thick second nozzle portion 82 is longer than the thin first nozzle portion 81. That is, the second nozzle portion 82 having a wall thickness close to the tip of the electrode 6 that becomes hot can be increased in the axial direction. Thereby, the heat resistance of the nozzle 8 can be improved.

The base end surface 802 of the nozzle 8 is arranged in the third cooling water passage W3. As a result, the nozzle 8 can be effectively cooled.

The insulating guide 7 is made of a material that is easily deformed. That is, the insulating guide 7 is made of resin and has an elastic modulus smaller than that of ceramic. Therefore, joining by press fitting is easier than with ceramics, and the sealing property can be improved. Further, the cost can be reduced as compared with the case where the insulating guide 7 is made of ceramic. Therefore, even if the electrode 6, the insulating guide 7, and the nozzle 8 are integrally replaced, the cost increase can be suppressed.

The resin-made insulation guide 7 has a smaller elastic modulus and is more easily deformed than a general ceramic as an insulation guide. Therefore, in order to seal between the insulating guide 7 and the electrode 6 and between the insulating guide 7 and the nozzle 8, it is not necessary to use an O-ring as in the case of the ceramic guide, and the resin insulating guide 7 itself is deformed. Allows fluid sealing. Therefore, not only can the insulating guide 7 be manufactured with a resin that is cheaper than ceramic, but also the O-ring can be omitted, which simplifies the torch structure.

The resin insulating guide 7 is cheaper than the ceramic insulating guide 7, but its heat resistance is low, so that there is a concern about thermal influence on the insulating guide 7. However, in the present embodiment, the first outer peripheral surface 75 of the insulation guide 7 is shorter than the second outer peripheral surface 76 in the axial direction of the insulation guide 7. By shortening the first outer peripheral surface 75 of the insulating guide 7 in this way, the tip of the insulating guide 7 can be arranged far away from the vicinity of the tip of the electrode 6 which becomes hot. Thereby, the heat influence on the insulation guide 7 can be reduced.

The replacement part unit 2a is fixed by sandwiching and holding the flange portion 14 of the shield cap 10 between the edge portion of the opening 41 of the first retainer cap 4 and the edge portion of the opening 51 of the second retainer cap 5. To. Therefore, the replacement part unit 2a can be easily removed by loosening the first retainer cap 4 as described above. Further, by attaching the second retainer cap 5 to the first retainer cap 4, the replacement component unit 2a can be easily attached.

In order to accurately position the replacement part unit 2a with respect to the central axis of the torch body 3, the gap between the replacement part unit 2a and the torch body 3 is as narrow as possible, and the binding force due to the O-ring is as strong as possible. Is preferable. However, for this reason, if a large force is required to attach / detach the replacement part unit 2a, workability may be reduced. In particular, there is a concern that workability may be reduced because a jig is required to attach / detach the replacement part unit 2a. However, in the replacement part unit 2a according to the present embodiment, as described above, the replacement part unit 2a can be easily attached to and detached from the first retainer cap 4 and the second retainer cap 5. Therefore, the replacement part unit 2a can be easily attached and detached without using a jig. Thereby, workability can be improved.
2. Second Embodiment Next, the plasma torch 1b according to the second embodiment will be described. FIG. 32 is a cross-sectional view taken along the central axis of the plasma torch 1b according to the second embodiment. FIG. 33 is a cross-sectional view of the replacement part unit 2b according to the second embodiment. 34 and 35 are perspective views of the replacement part unit 2b. 36 and 37 are perspective views of the nozzle 8 according to the second embodiment.

As shown in FIG. 33, the first outer peripheral surface 85 of the nozzle 8 has a recess 851. The recess 851 is provided in the second nozzle portion 82. The recess 851 is recessed inward in the radial direction of the nozzle 8 and extends in the circumferential direction of the nozzle 8. In the axial direction of the nozzle 8, the recess 851 is arranged at substantially the same position as the tip of the electrode 6. The outer diameter of the bottom of the recess 851 is smaller than the inner diameter of the inner peripheral surface 812 of the nozzle 8.

The recess 851 has a first wall surface 852 on the proximal end side and a second wall surface 853 on the distal end side. The first wall surface 852 is inclined with respect to the radial direction of the nozzle 8. The second wall surface 853 extends in the radial direction of the nozzle 8. As shown in FIG. 32, the first wall surface 852 extends parallel to the inclined inner peripheral surface of the first retainer cap 4. The recess 851 is arranged in the third cooling water passage W3.

In the present embodiment, the first retainer cap 4 is provided with a plurality of holes 43 communicating with the third cooling water passage W3. The hole 43 of the first retainer cap 4 communicates with the annular cooling water passage W12 between the first retainer cap 4 and the second retainer cap 5. In the axial direction of the nozzle 8, the recess 851 is arranged at substantially the same position as the hole 43 of the first retainer cap 4.

Other configurations of the replacement part unit 2b and the plasma torch 1b are the same as those of the replacement part unit 2a and the plasma torch 1a of the first embodiment.

In the second embodiment described above, since the nozzle 8 is provided with the recess 851, the surface area of the nozzle 8 in contact with the cooling water can be increased. Therefore, the cooling property of the nozzle 8 can be improved. Further, since the recess 851 is arranged at substantially the same position as the hole 43 of the first retainer cap 4, the cooling property of the nozzle 8 can be further improved. Further, in the cooling water passage W12, the second retainer cap 5 can also be water-cooled. Therefore, the replacement component unit 2b according to the present embodiment is suitable for plasma cutting using a large current.
3. 3. Other Embodiments Although one embodiment of the present invention has been described above, the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the gist of the invention.

The structure of the replacement parts units 2a and 2b may be changed. The structures of the torch body 3, the first retainer cap 4, and the second retainer cap 5 may be modified.

The electrode 6 and the insulating guide 7 may be joined by adhesion instead of press fitting. The insulation guide 7 and the nozzle 8 may be joined by adhesion instead of press fitting. The nozzle 8 and the insulating ring 9 may be joined by adhesion instead of press fitting. The insulating ring 9 and the shield cap 10 may be joined by adhesion instead of press fitting.

The insulating ring 9 and the shield cap 10 do not have to be included in the replacement component units 2a and 2b. That is, the replacement component unit may be composed of the electrode 6, the insulating guide 7, and the nozzle 8. Further, the insulating ring 9 and the shield cap 10 may be easily attached to and detached from the replacement component unit.

The inner diameter of the gas passage in the insulation guide 7 may be larger than the inner diameter of the nozzle 8. That is, as shown in FIG. 38, the inner diameter of the fifth main gas passage MG5 in the insulating guide 7 may be larger than the inner diameter of the sixth main gas passage MG6 in the nozzle 8.

According to the present invention, it is possible to provide a replacement component unit for a plasma torch that can improve the concentricity between the electrode and the nozzle and can be easily replaced.

2a, 2b Replacement part unit 6 Electrode 7 Insulation guide 8 Nozzle 5 2nd retainer cap

Claims (21)

With electrodes
A resin insulating guide having a hole into which the electrode is inserted and being joined to the electrode by press fitting,
A nozzle that has a hole into which the insulation guide is inserted and is joined to the insulation guide by press fitting.
With
The electrode and the insulating guide are joined to each other by press fitting so as to seal the fluid without an O-ring.
The insulating guide and the nozzle are joined to each other by press fitting so as to seal the fluid without an O-ring .
The outer peripheral surface of the electrode has an uneven shape that engages with the inner peripheral surface of the insulating guide.
The inner peripheral surface of the insulating guide has an uneven shape that engages with the outer peripheral surface of the electrode.
The concave-convex shape of the electrode and the concave-convex shape of the insulating guide prevent the insulating guide from coming off from the electrode.
Replacement parts unit for plasma torch. With electrodes
A resin insulating guide having a hole into which the electrode is inserted and being joined to the electrode by press fitting,
A nozzle that has a hole into which the insulation guide is inserted and is joined to the insulation guide by press fitting.
With
The electrode and the insulating guide are joined to each other by press fitting so as to seal the fluid without an O-ring.
The insulating guide and the nozzle are joined to each other by press fitting so as to seal the fluid without an O-ring.
The outer peripheral surface of the insulating guide has an uneven shape that locks to the inner peripheral surface of the nozzle.
The inner peripheral surface of the nozzle has an uneven shape that engages with the outer peripheral surface of the insulating guide.
The concave-convex shape of the insulating guide and the concave-convex shape of the nozzle prevent the nozzle from coming off from the insulating guide .
Replacement parts unit for up Razumatochi. The insulating guide is made of a material having a modulus of elasticity less than that of the ceramic.
The replacement part unit for a plasma torch according to claim 1 or 2. The electrode is
A joint to be joined to the insulation guide,
A flange portion having an outer diameter larger than that of the joint portion and including the base end of the electrode, and a flange portion.
Have,
The replacement part unit for a plasma torch according to any one of claims 1 to 3. The outer peripheral surface of the flange portion has a sealing surface that comes into contact with the O-ring.
The replacement part unit for a plasma torch according to claim 4. The flange portion is longer than the joint portion in the axial direction of the electrode.
The replacement part unit for a plasma torch according to any one of claims 4 or 5. The outer peripheral surface of the insulation guide is
A first outer peripheral surface arranged in the nozzle and joined to the nozzle,
A second outer peripheral surface located on the base end side of the first outer peripheral surface and arranged outside the nozzle.
Have,
In the axial direction of the insulation guide, the first outer peripheral surface is shorter than the second outer peripheral surface.
The replacement part unit for a plasma torch according to any one of claims 1 to 6. The second outer peripheral surface has a sealing surface that comes into contact with the O-ring.
The replacement part unit for a plasma torch according to claim 7. A portion of the second outer peripheral surface on the tip side of the sealing surface is arranged in the cooling water passage of the plasma torch.
The replacement part unit for a plasma torch according to claim 8. The outer peripheral surface of the insulation guide is
Further having a third outer peripheral surface located on the proximal end side of the second outer peripheral surface and having an outer diameter smaller than that of the second outer peripheral surface.
The third outer peripheral surface is arranged in the gas passage of the plasma torch.
The replacement part unit for a plasma torch according to any one of claims 7 to 9. The nozzle
The first nozzle portion to be joined to the insulation guide and
A second nozzle portion located on the tip side of the first nozzle portion, having a larger radial thickness than the first nozzle portion, and facing the electrode, and a second nozzle portion.
Have,
In the axial direction of the nozzle, the second nozzle portion is longer than the first nozzle portion.
The replacement part unit for a plasma torch according to any one of claims 1 to 10. The base end portion of the nozzle is arranged in the cooling water passage of the plasma torch.
The replacement part unit for a plasma torch according to any one of claims 1 to 11. The outer peripheral surface of the nozzle is recessed inward in the radial direction and has a recess extending in the circumferential direction.
The replacement part unit for a plasma torch according to any one of claims 1 to 12. In the axial direction of the nozzle, the recess is arranged at substantially the same position as the tip of the electrode.
The replacement part unit for a plasma torch according to claim 13. The plasma torch includes a retainer cap that is arranged to cover the nozzle.
The recess is arranged in a cooling water passage between the inner peripheral surface of the retainer cap and the outer peripheral surface of the nozzle.
The retainer cap is provided with a hole communicating with the cooling water passage.
In the axial direction of the nozzle, the recess is arranged at substantially the same position as the hole of the retainer cap.
The replacement part unit for a plasma torch according to claim 13 or 14. The wall surface on the base end side of the recess is inclined with respect to the radial direction of the nozzle and extends parallel to the inner peripheral surface of the retainer cap.
The replacement part unit for a plasma torch according to claim 15. The wall surface on the tip end side of the recess extends in the radial direction of the nozzle.
The replacement part unit for a plasma torch according to any one of claims 13 to 16. An insulating ring that has a hole into which the nozzle is inserted and is joined to the nozzle by press fitting or adhesion.
A shield cap having a hole into which the insulating ring is inserted and joined to the insulating ring by press fitting or adhesion.
Further prepare,
The replacement part unit for a plasma torch according to any one of claims 1 to 17. The plasma torch
A first retainer cap having an opening into which the plasma torch replacement component unit is inserted and arranged so as to cover the nozzle.
A second retainer cap having an opening into which the plasma torch replacement component unit is inserted and attached to the first retainer cap so as to cover the first retainer cap.
Have,
The nozzle or the shield cap has a flange portion that is sandwiched and held by an edge portion of the opening of the first retainer cap and an edge portion of the opening of the second retainer cap.
The replacement part unit for a plasma torch according to claim 18. The electrode is
With the electrode body
A joint located on the base end side of the electrode body and
A flange portion located on the base end side of the joint portion and a flange portion
A step portion provided between the flange portion and the joint portion,
Including
The insulation guide
The first outer peripheral surface arranged in the nozzle and
A second outer peripheral surface located on the base end side of the first outer peripheral surface and arranged outside the nozzle.
The first inner peripheral surface and
A second inner peripheral surface located closer to the base end surface than the first inner peripheral surface and reaching the base end surface of the insulating guide.
Including
The nozzle
The third inner peripheral surface reaching the base end surface of the nozzle and
The fourth inner peripheral surface located on the tip side of the third inner peripheral surface,
An inner step portion provided between the third inner peripheral surface and the fourth inner peripheral surface, and
Including
The base end surface of the insulating guide comes into contact with the step portion of the electrode.
The second inner peripheral surface of the insulation guide is joined to the joint portion of the electrode by press fitting.
The tip surface of the insulating guide comes into contact with the inner step portion of the nozzle.
The first outer peripheral surface of the insulation guide is joined to the third inner peripheral surface of the nozzle by press fitting.
The length from the base end surface of the nozzle to the inner step portion is shorter than the length of the second outer peripheral surface of the insulating guide.
The flange portion includes the base end of the electrode.
The replacement part unit for a plasma torch according to claim 1 or 2. The outer peripheral surface of the insulation guide is
A first outer peripheral surface arranged in the nozzle and joined to the nozzle,
A second outer peripheral surface located on the base end side of the first outer peripheral surface, arranged outside the nozzle, and having a diameter smaller than that of the first outer peripheral surface.
A third outer peripheral surface located on the proximal end side of the second outer peripheral surface, connected to the electrode, and having a diameter smaller than that of the second outer peripheral surface.
Have,
The replacement part unit for a plasma torch according to claim 1 or 2.

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