Plasma generator

Abstract

This plasma generating device comprises: a body cover that defines a reaction chamber, functions as a housing, and has an engagement section; and a base that is detachably attached to the body cover and has a to-be-engaged section, wherein the engagement section of the body cover is attached to the to-be-engaged section of the base.

Description

Technical Field

[0001] The present disclosure relates to a plasma generator in which a reaction chamber is defined by a main body cover that functions as a housing.

Background Art

[0002] The following patent document describes a plasma generator in which a reaction chamber is defined by a main body cover that functions as a housing.

Prior Art Literature

Patent Literature

[0003]

Patent Literature 1

Summary of the Invention

Problem to be Solved by the Invention

[0004] An object of the present specification is to enable easy attachment of the main body cover to a base.

Means for Solving the Problem

[0005] In order to solve the above problem, the present specification discloses a plasma generator comprising: a main body cover that defines a reaction chamber, functions as a housing, and has an engaging portion; and a base to which the main body cover is detachably attached and that has an engaged portion, An electrode for generating a discharge inside the reaction chamber, a holder for detachably holding the electrode, and a holder cover having a locking portion for fixing the holder inside the main body cover, wherein the engaging portion of the main body cover is attached to the engaged portion of the base The locking portion of the holder cover is attached to the locking portion of the base. .

Effect of the Invention

[0006] According to the present disclosure, the main body cover can be easily attached to the base.

Brief Description of the Drawings

[0007] [Figure 1] It is a diagram showing the plasma device. [Figure 2] This is a perspective view showing the plasma head. [Figure 3] Figure 2 is a cross-sectional view of the plasma head. [Figure 4] This is a magnified cross-sectional view of a plasma head. [Figure 5] This is a magnified cross-sectional view of a plasma head. [Figure 6] This is a cross-sectional view showing a conventional plasma head. [Figure 7] This is a perspective view showing a conventional plasma head. [Figure 8] This is a perspective view showing a conventional plasma head with the main unit cover and holder cover removed. [Figure 9] This is a perspective view showing a conventional plasma head with the main unit cover and holder cover removed. [Figure 10] This is a perspective view showing the plasma head with the main unit cover removed. [Figure 11] This is a perspective view showing the holder cover. [Figure 12] This is a perspective view showing the plasma head with the holder cover removed. [Modes for carrying out the invention]

[0008] Hereinafter, embodiments of the present invention will be described in detail with reference to the figures, as embodiments for carrying out the present invention.

[0009] As shown in Figure 1, the plasma apparatus 10 comprises a plasma head 11, a robot 13, and a control box 15. The plasma head 11 is attached to the robot 13. The robot 13 is, for example, a serial link robot (which can also be called an articulated robot), and the plasma head 11 is attached to the tip of the robot 13 via a bracket 12. The plasma head 11 is capable of irradiating plasma gas while attached to the tip of the robot 13. The plasma head 11 is capable of moving three-dimensionally in response to the movement of the robot 13.

[0010] The control box 15 is primarily composed of a computer and comprehensively controls the plasma apparatus 10. The control box 15 includes a power supply unit 15A that supplies power to the plasma head 11 and a gas supply unit 15B that supplies gas to the plasma head 11. The power supply unit 15A is connected to the plasma head 11 via a power cable (not shown). Based on the control of the control box 15, the power supply unit 15A changes the voltage applied to the electrodes 30 of the plasma head 11 (see Figures 3 to 5).

[0011] Furthermore, the gas supply unit 15B is connected to the plasma head 11 via a gas tube 19. Based on the control of the control box 15, the gas supply unit 15B supplies the reaction gas, which will be described later, to the plasma head 11. The control box 15 controls the gas supply unit 15B and controls the amount of gas supplied from the gas supply unit 15B to the plasma head 11. As a result, the robot 13 operates based on the control of the control box 15 and irradiates the workpiece W placed on the table 17 with plasma gas from the plasma head 11.

[0012] Furthermore, the control box 15 is equipped with an operation unit 15C that has a touch panel and various switches. The control box 15 displays various setting screens and operating status (for example, gas supply status, etc.) on the touch panel of the operation unit 15C. The control box 15 also receives various information through operation input to the operation unit 15C.

[0013] As shown in FIG. 2 and FIG. 3, the plasma head 11 includes a main body cover 20, an internal cable 22, a cable holder 24, a collar 25, a holder attachment 26, an electrode holder 28, an electrode 30, a holder cover 31, and the like. The main body cover 20 functions as a housing and is formed of a metal material. Also, the main body cover 20 is generally cylindrical in shape. However, the main body cover 20 has a shape that tapers toward the downward direction, and the lower end portion of the main body cover 20 has a conical shape. Therefore, the lower end portion of the main body cover 20 functions as the nozzle 32 of the plasma head 11. Also, the main body cover 20 is fixed to the lower end of the cable holder 24 at the upper end portion thereof.

[0014] As shown in FIG. 4 and FIG. 5, the internal cable 22 is disposed inside the main body cover 20 so as to extend in the axial direction of the main body cover 20, and is fixed inside the main body cover 20 by the cable holder 24. The cable holder 24 is generally cylindrical, and is fixedly fitted inside the main body cover 20. Then, the internal cable 22 is fixedly fitted to the upper end portion inside the cable holder 24. Accordingly, the internal cable 22 is fixed inside the main body cover 20 by the cable holder 24. Note that at the lower end portion of the cable holder 24, a gap 35 is formed between the inner peripheral surface of the cable holder 24 and the outer peripheral surface of the internal cable 22.

[0015] Also, the collar 25 has a stepped cylindrical shape, and is constituted by a small diameter portion 36, a large diameter portion 37, and a step surface 38. The outer diameter of the small diameter portion 36 is smaller than the inner diameter of the cable holder 24. The small diameter portion 36 is inserted into the cable holder 24, and the lower end of the small diameter portion 36 slightly extends downward from the lower end of the cable holder 24. The step surface 38 connects the small diameter portion 36 and the large diameter portion 37, and is positioned below the cable holder 24. An O-ring 39 is disposed along the outer peripheral surface of the small diameter portion 36 between the lower end surface of the cable holder 24 and the step surface 38. Also, the outer diameter of the large diameter portion 37 is smaller than the inner diameter of the main body cover 20, and the large diameter portion 37 is positioned inside the main body cover 20.

[0016] Further, the holder attachment 26 is annular in shape, and the outer diameter of the holder attachment 26 is the same as the outer diameter of the large-diameter portion 37 of the collar 25. The holder attachment 26 is disposed below the large-diameter portion 37 of the collar 25. A thread groove is formed on the inner circumferential surface of the annular holder attachment 26, and the inner circumferential surface of the holder attachment 26 functions as a screw hole. Further, a plurality of through-holes 40 penetrating in the vertical direction are formed at the outer edge of the holder attachment 26. The plurality of through-holes 40 are inclined at a predetermined angle.

[0017] Further, the electrode holder 28 is formed of a metal material and is generally cylindrical in shape. However, the electrode holder 28 has a shape that tapers toward the lower side, and a convex portion 46 is formed at the center of the upper end surface of the electrode holder 28. A screw thread is formed on the outer circumferential surface of the convex portion 46. Therefore, when the convex portion 46 of the electrode holder 28 is inserted into and screwed into the inner circumferential surface of the holder attachment 26 that functions as a screw hole, the electrode holder 28 is detachably attached to the holder attachment 26.

[0018] Furthermore, the inner surface of the electrode holder 28 has a stepped shape. The upper part of the inner surface of the electrode holder 28 is a small-diameter first inner surface 50, and the lower part of the inner surface of the electrode holder 28 that is continuous with the first inner surface 50 is a second inner surface 52 that is larger in diameter than the first inner surface 50. The lower end of the crimp terminal 56 is inserted into the first inner surface 50. The outer diameter of the lower end of the crimp terminal 56 is slightly smaller than the inner diameter of the first inner surface 50 of the electrode holder 28. For this reason, the crimp terminal 56 is fixed to the first inner surface 50 of the electrode holder 28 by a mortise bolt 58. More specifically, a radially extending lateral hole 60 is formed on the upper end side of the electrode holder 28, and this lateral hole 60 communicates with the first inner surface 50. The crimp terminal 56 is then fixed to the first inner surface 50 of the electrode holder 28 by screwing the grub bolt 58 into the lateral hole 60. The depth of the lateral hole 60 is longer than the length of the grub bolt 58. Therefore, when the grub bolt 58 is screwed into the lateral hole 60, it is embedded in the lateral hole 60 and is not exposed to the outside from the surface of the electrode holder 28. The crimp terminal 56 extends upward from the upper end of the first inner surface 50 of the electrode holder 28. The crimp terminal 56 extending upward from the first inner surface 50 of the electrode holder 28 and the internal cable 22 are connected by a conductor 62.

[0019] Furthermore, the electrode 30 is a round bar shape, and its outer diameter is slightly smaller than the inner diameter of the second inner surface 52 of the electrode holder 28. The electrode 30 is inserted into the second inner surface 52 of the electrode holder 28, and the electrode 30 is fixed to the second inner surface 52 of the electrode holder 28 by a enamel bolt 66. Specifically, a radially extending lateral hole 68 is formed on the lower end side of the electrode holder 28, and this lateral hole 68 communicates with the second inner surface 52. The electrode 30 is fixed to the second inner surface 52 of the electrode holder 28 by screwing the enamel bolt 66 into the lateral hole 68. The depth dimension of the lateral hole 68 is longer than the length dimension of the enamel bolt 66. Therefore, when the enamel bolt 66 is screwed into the lateral hole 68, it is embedded in the lateral hole 68 and is not exposed to the outside from the surface of the electrode holder 28. Furthermore, the electrode 30 is fixed on the second inner circumferential surface 52 with its lower end, i.e., tip, extending by a predetermined amount (for example, 3 to 5 mm) from the lower end of the electrode holder 28.

[0020] Furthermore, the holder cover 31 is generally cylindrical in shape, and its inner diameter is slightly larger than the outer diameter of the large-diameter portion 37 of the collar 25 and the outer diameter of the holder mounting fitting 26. The large-diameter portion 37 of the collar 25 and the holder mounting fitting 26 are inserted into the holder cover 31. The holder cover 31 is fixed to the cable holder 24 at its upper end. On the other hand, a flange 70 extending inward is formed at the lower end of the holder cover 31. With this structure, the large-diameter portion 37 of the collar 25 and the holder mounting fitting 26 are sandwiched between the lower end surface of the cable holder 24 and the flange 70 of the holder cover 31. In this way, the electrode holder 28 is held by the holder cover 31 by being sandwiched between the large-diameter portion 37 of the collar 25 and the holder mounting fitting 26 between the lower end surface of the cable holder 24 and the flange 70 of the holder cover 31. Furthermore, the large-diameter portion 37 of the collar 25 and the holder mounting fixture 26 are biased toward the flange 70 of the holder cover 31 by the elastic force of the O-ring 39. As a result, the holder cover 31, which is fixed to the holder mounting fixture 26, is biased downward by the elastic force of the O-ring 39. In addition, the outer diameter of the holder cover 31 is smaller than the inner diameter of the main body cover 20, and it is located inside the main body cover 20.

[0021] Furthermore, a gas supply unit 15B is connected to the gap 35 between the inner circumferential surface of the cable holder 24 and the outer circumferential surface of the internal cable 22 via a gas tube 19 (see Figure 1), and the reaction gas supplied from the gas supply unit 15B flows into the gap 35 between the inner circumferential surface of the cable holder 24 and the outer circumferential surface of the internal cable 22. The reaction gas then flows downward and flows around the electrode holder 28 through multiple through holes 40 of the holder mounting device 26. As mentioned above, the multiple through holes 40 are inclined at a predetermined angle, so the reaction gas is straightened to a predetermined angle as it passes through the multiple through holes 40. The reaction gas straightened by the multiple through holes 40 flows further downward and flows around the electrode 30 extending from the lower end of the electrode holder 28, reaching the nozzle 32 of the main body cover 20. In other words, the reaction gas flows into the main body cover 20 from the gap 35 between the inner surface of the cable holder 24 and the outer surface of the internal cable 22, through the multiple through holes 40 of the holder mounting device 26, around the electrode holder 28 and the electrode 30 extending from the lower end of the electrode holder 28, and reaches the nozzle 32 of the main body cover 20.

[0022] Oxygen (O2) can be used as the reaction gas (seed gas). The gas supply unit 15B, for example, introduces a mixed gas of oxygen and nitrogen (N2) (for example, dry air (Air)) into the gap 35 between the inner circumferential surface of the cable holder 24 and the outer circumferential surface of the internal cable 22 via a gas tube 19 (see Figure 1). Hereinafter, this mixed gas will be conveniently referred to as the reaction gas, and oxygen will be referred to as the seed gas.

[0023] Furthermore, a voltage is applied to the electrode 30 extending from the lower end of the electrode holder 28 from the power supply unit 15A of the control box 15. Specifically, power is supplied from the power supply unit 15A of the control box 15 to the internal cable 22 of the plasma head 11 via the power cable, and power is supplied to the conductor 62 and the crimp terminal 56. The power supplied to the crimp terminal 56 then flows to the electrode 30 via the electrode holder 28. In this way, power is supplied to the electrode 30, and a voltage is applied to the electrode 30. At this time, as shown in Figure 5, a pseudo-arc A is generated from the tip of the electrode 30 by the application of voltage to the electrode 30. Since the pseudo-arc A is generated along the flow of the reaction gas, it is generated downward from the tip of the electrode 30 and reaches the tip of the nozzle 32. Therefore, a pseudo-arc A is generated between the tip of the electrode 30 and the tip of the nozzle 32. When the reaction gas passes through the pseudo-arc A generated between the tip of the electrode 30 and the tip of the nozzle 32, the reaction gas is plasma-fied. Therefore, a pseudo-arc A discharge occurs between the tip of the electrode 30 and the tip of the nozzle 32, causing the reaction gas to become plasma and generating plasma gas. In other words, inside the reaction chamber 76 partitioned by the main body cover 20, the reaction gas becomes plasma and plasma gas is generated.

[0024] With this structure, plasma gas is generated in the plasma head 11 by a discharge between the tip of the electrode 30 and the tip of the nozzle 32, and is ejected from the opening 32A formed at the tip of the nozzle 32. The plasma gas is then ejected from the opening 32A of the nozzle 32, thereby performing plasma treatment on the workpiece W. In the plasma head 11, which generates plasma gas by a discharge between the tip of the electrode 30 and the tip of the nozzle 32 in this way, the tip of the electrode 30 wears down. For this reason, in the plasma head 11, the amount of extension of the tip of the electrode 30 from the electrode holder 28 can be adjusted using the enamel bolt 66, and the electrode 30 can also be replaced.

[0025] More specifically, before the plasma treatment is performed by the plasma head 11, the amount of extension of the tip of the electrode 30 from the electrode holder 28 is adjusted so that the tip of the electrode 30 extends by a predetermined amount (for example, 3 to 5 mm) from the lower end of the electrode holder 28. In other words, the screwing of the enamel bolt 66 into the lateral hole 68 is loosened and adjusted so that the amount of extension of the tip of the electrode 30 from the electrode holder 28 is a predetermined amount (for example, 3 to 5 mm). Then, after the enamel bolt 66 is screwed into the lateral hole 68 and the electrode 30 is fixed inside the electrode holder 28, a reaction gas is supplied to the plasma head 11 and a voltage is applied to the electrode 30, thereby performing the plasma treatment by the plasma head 11. As the plasma treatment is performed in this way, the tip of the electrode 30 gradually wears down, and the amount of extension of the tip of the electrode 30 from the electrode holder 28 decreases.

[0026] In this way, when the amount of the electrode 30's tip extending from the electrode holder 28 falls below a predetermined amount, the amount of the electrode 30's tip extending from the electrode holder 28 is adjusted. That is, the screwing of the enamel bolt 66 into the lateral hole 68 is loosened, and the electrode 30 is lowered so that the amount of the electrode 30's tip extending from the electrode holder 28 becomes the predetermined amount. After the amount of the electrode 30's tip extending from the electrode holder 28 becomes the predetermined amount, the enamel bolt 66 is screwed into the lateral hole 68, fixing the electrode 30 inside the electrode holder 28. This makes it possible to restore the amount of the electrode 30's tip extending to the predetermined amount if it falls below a predetermined amount.

[0027] Furthermore, if the extension amount of the electrode 30 tip is repeatedly adjusted, the electrode 30 will become shorter, making it impossible to fix the electrode 30 with the enamel bolt 66. In other words, for example, if the length of the electrode 30 becomes approximately the same as the length between the lower end surface of the electrode holder 28 and the position where the lateral hole 68 is formed, it will no longer be possible to fix the electrode 30 with the enamel bolt 66 while the tip of the electrode 30 extends beyond the lower end of the electrode holder 28. In this case, when it becomes impossible to fix the electrode 30 with the enamel bolt 66, the electrode 30 is replaced. That is, the screwing of the enamel bolt 66 into the lateral hole 68 is loosened, and the used electrode 30 is removed from the second inner circumferential surface 52 of the electrode holder 28. Then, a new electrode 30 is inserted into the second inner circumferential surface 52 of the electrode holder 28, and the new electrode 30 is fixed inside the electrode holder 28 with the enamel bolt 66.

[0028] Furthermore, as described above, the multiple through holes 40 formed in the holder mounting device 26 are inclined to rectify the reaction gas flow. For this reason, multiple holder mounting devices 26 with different inclination angles of the through holes 40 are provided, and the holder mounting devices 26 are replaced to adjust the rectification angle of the reaction gas. In other words, as described above, the holder mounting device 26 is detachably screwed into the protrusion 46 of the electrode holder 28, so the holder mounting device 26 is replaced by removing the holder mounting device 26 from the protrusion 46 and attaching a different holder mounting device 26 to the protrusion 46.

[0029] In this way, the plasma head 11 allows for adjustment of the extension amount of the electrode 30 and replacement of the electrode 30 and holder mounting device 26. When adjusting the extension amount of the electrode 30 or replacing the electrode 30 and holder mounting device 26, the main body cover 20 and holder cover 31 are removed from the cable holder 24. However, the plasma head 11 allows for more efficient adjustment of the extension amount of the electrode 30 and replacement of the electrode 30 and holder mounting device 26 compared to conventional plasma heads.

[0030] More specifically, as shown in Figure 6, the conventional plasma head 100 includes a main body cover 110, internal cable 112, cable holder 114, collar 115, holder mounting device 116, electrode holder 118, electrode 120, holder cover 122, crimp terminal 124, conductor 126, etc. The main body cover 110 functions as a housing and is made of a metal material. The main body cover 110 has the same shape as the main body cover 20 of the plasma head 11, and the lower end of the main body cover 20 functions as a nozzle 128. Also, as shown in Figure 7, the main body cover 110 is fixed to the lower surface of the cable holder 114 by six bolts (only four are shown in the figure) 132 at the flange portion 130 at the upper end.

[0031] Furthermore, the internal cable 112, cable holder 114, collar 115, holder mounting fixture 116, electrode holder 118, electrode 120, holder cover 122, crimp terminal 124, and conductor 126 have substantially the same structure as the internal cable 22, cable holder 24, collar 25, holder mounting fixture 26, electrode holder 28, electrode 30, holder cover 31, crimp terminal 56, and conductor 62 of the plasma head 11, so their explanation is omitted. Note that in the conventional plasma head 100, the electrode 120 is fixed inside the electrode holder 118 by a enamel bolt 136, and the crimp terminal 124 is fixed inside the electrode holder 118 by a enamel bolt 138. Furthermore, while the holder cover 31 of the plasma head 11 is fixed to the cable holder 24, the holder cover 122 of the conventional plasma head 100 is not fixed to the cable holder 114.

[0032] In a conventional plasma head 100 with this structure, when adjusting the extension amount of the electrode 120 or replacing the electrode 120 and holder mounting fixture 116, the operator removes six bolts (only four are shown in the figure) 132 using a screwdriver or other tool, as shown in Figure 8. This removes the main body cover 110 from the cable holder 114, exposing the electrode holder 118. Therefore, the operator can adjust the extension amount of the electrode 120 or replace the electrode 120 by manipulating the set bolts 136. In addition, in a conventional plasma head 100, the holder cover 122 is not fixed to the cable holder 114, so when the main body cover 110 is removed from the cable holder 114, the holder cover 122 detaches from the cable holder 114 due to its own weight. Thus, when the holder cover 122 detaches from the cable holder 114, the electrode holder 118 is no longer held by the holder cover 122. Therefore, the electrode holder 118 is removed from the plasma head 100 by the operator manipulating the enamel bolt 138. In this way, the electrode holder 118 is removed from the plasma head 100, and the holder mounting fixture 116 attached to the electrode holder 118 is replaced.

[0033] Thus, in the conventional plasma head 100, the operator removes the main body cover 110 from the cable holder 114 by removing six bolts 132 with a tool, and then adjusts the extension amount of the electrode 120 and replaces the electrode 120 and electrode holder 118. However, when the main body cover 110 is removed from the cable holder 114, the holder cover 122 detaches, and the electrode holder 118 is no longer held in place by the holder cover 122. In this state, the electrode holder 118 is suspended in mid-air, supported by the conductor 126, as shown in Figure 9. The collar 115 is held between the lower surface of the cable holder 114 and the holder mounting device 116. In this suspended state, supported by the conductor 126, a load is placed on the conductor 126, and there is a risk that the conductor 126 may break. In other words, with the conventional plasma head 100, each time the extension amount of the electrode 120 is adjusted or the electrode 120 and electrode holder 118 are replaced, a load is placed on the conductor 126, and there is a risk that the conductor 126 may break. Furthermore, in order to adjust the extension amount of the electrode 120 or replace the electrode 120 and electrode holder 118, the operator needs to remove six bolts 132 with a tool, which is burdensome for the operator and increases the working time. Moreover, since the bolts 132 are small, they are easily lost.

[0034] In light of the above, the plasma head 11 allows the main body cover 20 to be attached to the cable holder 24 without the use of tools. Specifically, as shown in Figure 10, a male screw 150 is formed on the outer circumference of the lower end of the cable holder 24. On the other hand, a female screw 152 is formed on the inner circumference of the upper end of the main body cover 20. The operator then rotates the main body cover 20 in the direction of arrow 154 (clockwise) to fasten the male screw 150 and the female screw 152 together, thereby attaching the main body cover 20 to the cable holder 24. This allows the operator to easily attach the main body cover 20 to the cable holder 24 without the use of tools. Conversely, the operator rotates the main body cover 20 in the direction of arrow 156 (counterclockwise) to release the fastening of the male screw 150 and the female screw 152, thereby removing the main body cover 20 from the cable holder 24. This allows the operator to easily remove the main body cover 20 from the cable holder 24 without the use of tools. Thus, with the plasma head 11, the operator can attach and detach the main body cover 20 to the cable holder 24 simply by rotating the main body cover 20 without using any tools.

[0035] Furthermore, the holder cover 31 can be attached to the cable holder 24 without the use of tools. Specifically, as shown in Figure 11, the holder cover 31 has recesses 160 cut out in an L-shape at three equally spaced positions at its upper end. The recesses 160 consist of a first notch 162 extending in the vertical direction and a second notch 164 extending in a direction perpendicular to the first notch 162. A slight indentation 166 is formed at the tip of the second notch 164, pointing upward. On the other hand, as shown in Figure 12, three pins 168 (two pins 168 are shown in Figure 12) are erected on the outer circumferential surface of the lower end of the cable holder 24 at three equally spaced positions below the male screw 150. The worker then moves the holder cover 31 in the direction of arrow 170 (upward), inserting the pins 168 into the first notch 162 of the recess 160. Then, by rotating the holder cover 31 in the direction of arrow 172 (clockwise), the pin 168 is inserted into the second notch 164 of the recess 160 and secured. This allows the worker to easily attach the holder cover 31 to the cable holder 24 without using any tools. Furthermore, by rotating the holder cover 31 in the direction of arrow 174 (counterclockwise), the engagement of the pin 168 with the second notch 164 is released. Then, by moving the holder cover 31 in the direction of arrow 176 (downward), the pin 168 is removed from the first notch 162. This allows the worker to easily remove the holder cover 31 from the cable holder 24 without using any tools. In this way, the worker can attach and detach the holder cover 31 to the cable holder 24 without using any tools. Note that, as described above, the holder cover 31 is biased downward by the elastic force of the O-ring 39. In other words, the holder cover 31 is biased in the direction opposite to the insertion direction by the elastic force of the O-ring 39. Therefore, when the holder cover 31 is attached to the cable holder 24, that is, when the pin 168 is hooked into the second notch 164, the elastic force of the O-ring 39 biases the pin 168 toward the recess 166 of the second notch 194.This prevents the pin 168 from coming out of the second notch 194 when the holder cover 31 is attached to the cable holder 24.

[0036] Thus, in the plasma head 11, the main body cover 20 and the holder cover 31 can be attached to the cable holder 24 without the use of tools, which allows for convenient adjustment of the electrode extension amount and replacement of the electrode 30 and the holder mounting device 26. Specifically, as shown in Figure 10, the main body cover 20 is removed from the cable holder 24 by the operator rotating the main body cover 20 in the direction of arrow 156 (counterclockwise). At this time, the holder cover 31 is fixed to the cable holder 24 by pins 168 and recesses 160. Therefore, as shown in Figure 10, when the main body cover 20 is removed from the cable holder 24, the electrode holder 28 is exposed, held by the holder cover 31 together with the holder mounting device 26. Therefore, the operator can adjust the electrode extension amount and replace the electrode 30 by operating the grub bolt 66 on the electrode holder 28, which is held by the holder cover 31. As a result, the plasma head 11 can adjust the extension amount of the electrode 30 and replace the electrode 30 without putting a load on the conductor 62. In addition, the operator can remove the main body cover 20 from the cable holder 24 without using tools to expose the electrode holder 28, thereby reducing the burden on the operator when adjusting the extension amount of the electrode 30 and replacing the electrode 30, and shortening the working time. Furthermore, since there are no small parts such as bolts 132, the loss of parts can also be prevented.

[0037] Furthermore, the main body cover 20 is attached to the cable holder 24 by a screw-in mechanism, and the holder cover 31 is attached to the cable holder 24 by a mechanism that hooks a pin 168 into a recess 160. This prevents the holder cover 31 from rotating along with the main body cover 20 when the worker rotates the main body cover 20 to remove it from the cable holder 24. In other words, for example, if the holder cover 31 is attached to the cable holder 24 by a screw-in mechanism, there is a risk that the holder cover 31 will rotate along with the main body cover 20 when the worker rotates the main body cover 20 to remove it from the cable holder 24. If the holder cover 31 rotates in this way, the crimp terminal 56 will rotate along with the holder mounting device 26 inside the holder cover 31, and there is a risk that the conductor 62 will twist and break. In light of this, the holder cover 31 is attached to the cable holder 24 by a mechanism different from the screw-in mechanism. This prevents the holder cover 31 from rotating along with the main body cover 20 when the worker rotates the main body cover 20 to remove it from the cable holder 24, thereby preventing the conductor 62 from breaking.

[0038] Furthermore, since the electrode holder 28 is held together with the holder mounting device 26 by the holder cover 31, it is necessary to remove the holder cover 31 from the cable holder 24 when replacing the holder mounting device 26. For this reason, when replacing the holder mounting device 26, the operator removes the main body cover 20 from the cable holder 24, and then, as shown in Figure 12, rotates the holder cover 31 in the direction of arrow 174 and moves it in the direction of arrow 176 to remove the holder cover 31 from the cable holder 24. As a result, the electrode holder 28 is no longer held by the holder cover 31. Then, by operating the grub bolt 58, the electrode holder 28 is removed from the plasma head 11, and the holder mounting device 26 is replaced. In this way, when replacing the holder mounting device 26, the operator can remove the main body cover 20 and the holder cover 31 from the cable holder 24 without using tools, thereby reducing the burden on the operator and shortening the work time. Furthermore, because there are no small parts like bolt 132, it also prevents parts from being lost.

[0039] Incidentally, the plasma head 11 is an example of a plasma generator. The main body cover 20 is an example of a main body cover. The cable holder 24 is an example of a base. The electrode holder 28 is an example of a holder. The electrode 30 is an example of an electrode. The holder cover 31 is an example of a holder cover. The O-ring 39 is an example of an elastic body. The reaction chamber 76 is an example of a reaction chamber. The male screw 150 is an example of an engaged part and a male screw. The female screw 152 is an example of an engaged part and a female screw. The recess 160 is an example of a locking part and a recess. The first notch 162 is an example of a first notch. The second notch 164 is an example of a second notch. The pin 168 is an example of a locked part and a protrusion.

[0040] In the embodiment described above, the following effects are achieved.

[0041] The plasma head 11 comprises a main body cover 20 that partitions the reaction chamber 76 and functions as a housing, and a cable holder 24 to which the main body cover 20 is detachably attached. The engaging portion of the main body cover 20 is attached to the locking portion of the cable holder 24. This allows the main body cover 20 to be easily attached to and detached from the cable holder 24.

[0042] Furthermore, the cable holder 24 has a male screw 150 as an engaging part, and the main body cover 20 has a female screw 152 as an engaging part. The main body cover 20 is attached to the cable holder 24 by screwing the male screw 150 and the female screw 152 together. As a result, the operator can attach and detach the main body cover 20 to the cable holder 24 simply by rotating the main body cover 20.

[0043] Furthermore, the plasma head 11 includes an electrode 30 that generates a discharge inside the reaction chamber 76, an electrode holder 28 that detachably holds the electrode 30, and a holder cover 31 for fixing the electrode holder 28 inside the main body cover 20. The locking portion of the holder cover 31 is attached to the locking portion of the cable holder 24. This allows the electrode holder 28 to be easily held by the holder cover 31.

[0044] Furthermore, a recess 160 is formed in the holder cover 31 as a locking part, and a pin 168 is formed in the cable holder 24 as a locking part. The holder cover 31 is attached to the cable holder 24 by engaging the pin 168 with the recess 160. This allows the holder cover 31 to be attached to the cable holder 24 with a simple structure.

[0045] Furthermore, the recess 160 is composed of a first notch 162 extending in the insertion direction of the holder cover 31 and a second notch 164 extending in a direction intersecting the insertion direction. The holder cover 31 is attached to the cable holder 24 by hooking the pin 168 into the second notch 164 of the recess 160. The plasma head 11 is also equipped with an O-ring 39 that biases the holder cover 31 in the direction opposite to the insertion direction of the holder cover 31. As a result, the pin 168, which is hooked into the second notch 164, is biased toward the wall surface that defines the second notch 164 by the elastic force of the O-ring 39. This ensures that the pin 168 is hooked into the second notch 164, that is, that the holder cover 31 is attached to the cable holder 24.

[0046] Furthermore, this disclosure is not limited to the above embodiments, and can be implemented in various forms with various modifications and improvements based on the knowledge of those skilled in the art. Specifically, for example, in the above embodiment, the main body cover 20 is attached to the cable holder 24 by a screw-in mechanism, and the holder cover 31 is attached to the cable holder 24 by a latching mechanism in which a pin 168 is hooked into a recess 160. Alternatively, the holder cover 31 may be attached to the cable holder 24 by a screw-in mechanism, and the main body cover 20 may be attached to the cable holder 24 by a latching mechanism. Also, the main body cover 20 and the holder cover 31 may be attached to the cable holder 24 by a screw-in mechanism, or the main body cover 20 and the holder cover 31 may be attached to the cable holder 24 by a latching mechanism. Moreover, various mechanisms can be adopted, not limited to screw-in mechanisms and latching mechanisms, as long as they allow the main body cover 20 and the holder cover 31 to be attached to the cable holder 24 without the use of tools. For example, a quick joint, a mechanism utilizing the structure of a so-called coupler (registered trademark), a push-lock mechanism, a cam-lock mechanism, etc. can be adopted.

[0047] Furthermore, in the above embodiment, the holder cover 31 is biased in the direction opposite to the insertion direction by the elastic force of the O-ring 39, but the holder cover 31 may also be biased in the insertion direction. That is, for example, a tension spring or the like may be placed between the holder cover 31 and the cable holder 24 to bias the holder cover 31 in the insertion direction. In this way, even if the holder cover 31 is biased in the insertion direction, the same effect as when the holder cover 31 is biased in the direction opposite to the insertion direction can be obtained.

[0048] Furthermore, in the above embodiment, a discharge is generated between the tip of the electrode 30 and the tip of the main body cover 20 to turn the processing gas into plasma. In other words, a discharge is generated by a single electrode 30. On the other hand, a discharge may be generated between multiple electrodes. An electrode holder 28 that holds at least one of these multiple electrodes is held by the holder cover 31. [Explanation of symbols]

[0049] 11: Plasma head (plasma generator) 20: Main body cover 24: Cable holder (base) 28: Electrode holder (holder) 30: Electrode 31: Holder cover 39: O-ring (elastic body) 76: Reaction chamber 150: Male screw (engaged part) 152: Female screw (engaged part) 160: Recess (locking part) 162: First notch 164: Second notch 168: Pin (locked part) (protruding part)

Claims

1. The main body cover partitions the reaction chamber and functions as a housing, and has an engaging portion. The main body cover is detachably attached and has a base with an engagement portion, An electrode that generates a discharge inside the reaction chamber, A holder that detachably holds the electrode, A holder cover having a locking portion for fixing the holder inside the main body cover, Equipped with, The engagement portion of the main body cover is attached to the engaged portion of the base. A plasma generator in which the locking portion of the holder cover is attached to the locking portion of the base.

2. The main body cover has either a male screw or a female screw formed as the engagement portion. The base has the other of the male screw and the female screw formed on it as the engaged portion. The plasma generating apparatus according to claim 1, wherein the main body cover is attached to the base by screwing the male screw and the female screw together.

3. The holder cover has either a protrusion or a recess formed as the locking portion. The base has the other of the convex portion and the concave portion formed as the locking portion. The plasma generating apparatus according to claim 1 or claim 2, wherein the holder cover is attached to the base by engaging the convex portion and the concave portion.

4. The recess is composed of a first notch extending in the insertion direction of the holder cover and a second notch extending in a direction intersecting the insertion direction. The holder cover is attached to the base by engaging the protrusion with the second notch of the recess. The plasma generating apparatus according to claim 3, further comprising an elastic body that biases the holder cover in one of the insertion direction and the direction opposite to the insertion direction.

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