JP6341494B2 - Ion generator - Google Patents

Description

  The present invention relates to an ion generating apparatus used for plasma processing of a surface to be processed.

2. Description of the Related Art Conventionally, an ion generating apparatus that discharges ions generated in a casing by a discharge between a discharge electrode to which a high voltage is applied and a ground electrode as an ion flow using a compressed fluid is known.
In such an apparatus, not only a ground electrode that surrounds the discharge electrode but also a metal conductive plate in which a flow hole serving as an ion ejection port is formed at the tip of the casing, and this conductive plate is used as a ground electrode. .

Japanese Patent No. 4082905

As described above, when the ground electrode is formed of a conductive plate having a flow hole serving as an ion outlet, a discharge is also generated between the conductive plate and the discharge electrode. When the ions pass through the flow holes as an ion stream, the conductive plate is damaged.
Due to such ion damage, the through holes formed in the conductive plate may be consumed, and the opening diameter may increase or the direction of the through holes may be bent. Thus, when the flow hole is deformed, the direction and speed of the pressure fluid ejected through the flow hole are changed. Actually, since the flow velocity of the pressure fluid drops, the target ion flow may not be ejected.
Therefore, there is a problem that the conductive plate in which the flow holes are formed must be frequently replaced to stabilize the ion flow.

On the other hand, if the damaged conductive plate is not replaced, there is also a problem that the ion flow does not reach the position away from the ejection port.
An object of the present invention is to provide an ion generating apparatus capable of stabilizing an ion flow radiated from an ion ejection port over a long period of time without increasing the replacement frequency of components constituting the ion ejection port. .

  The present invention comprises a casing connected to a pressure fluid source and provided with an ion ejection port, a discharge electrode provided in the casing and applying a high voltage, and a ground electrode for discharging between the discharge electrode, And an ion generator that generates ions by applying a high voltage to the discharge electrode and discharges between the discharge electrode and the ground electrode, and ejects the ions from the ion outlet.

  The ion jet port has a plurality of flow holes formed therein, a conductive plate constituting the ground electrode, and a plurality of flow holes formed in the flow direction of the pressure fluid supplied from the pressure fluid source. An insulating plate made of an inorganic material provided on the downstream side of the conductive plate, with the conductive plate and the tip end surface of the discharge electrode facing each other, and via the flow hole of the conductive plate and the flow hole of the insulating plate It is characterized in that the ions are ejected by the pressure fluid.

According to the present invention, since the ion ejection port is formed and the insulating plate is provided on the downstream side of the conductive plate constituting the ground electrode, the flow hole of the conductive plate is damaged by the ions passing through the flow hole. Even if the opening is deformed or enlarged, the direction and flow velocity of the ion flow can be maintained by the through holes of the insulating plate that are hardly damaged by ions.
When the member constituting the ion ejection port is formed only of the conductive material, the flow hole is deformed in a short period of time, and the target ion flow is not released, so that frequent replacement of parts is necessary. According to this invention, even if the flow hole of the conductive plate changes, if the flow hole of the downstream insulating plate does not change, the desired ion flow direction and momentum can be maintained. The ion flow can be stabilized over a long period of time while dramatically extending the cycle.
In particular, the merit of extending the replacement cycle of expensive metal plates such as tungsten and molybdenum with relatively little ion damage is great.

  In the second aspect of the invention, the side of the insulating plate that is in close contact with the conductive plate, i.e., the upstream opening diameter is larger than the opening diameter of the conductive plate, so that it is ejected from the conductive plate. The ion flow can be reliably guided to the flow hole of the insulating plate.

FIG. 1 is a cross-sectional view of the embodiment. FIG. 2 is an axial cross-sectional view in the vicinity of the ion ejection port in the embodiment. FIG. 3 is a front view of the ion ejection port in the embodiment. FIG. 4 is an enlarged cross-sectional view of the vicinity of the connection portion between the first conductive pipe and the second conductive pipe in the embodiment. FIG. 5 is an enlarged cross-sectional view of the vicinity of the rear end of the second conductive pipe in the embodiment. 6A and 6B are diagrams showing the results of a test for confirming the effect of the ion generation apparatus of the embodiment. FIG. 6A shows the apparatus of the embodiment, and FIGS. FIG. 7 is an explanatory diagram of an ion jet port according to the embodiment.

1 to 7 show an embodiment of the present invention.
An electric motor m is fixed to the fixing means a, and a drive gear 2 is fixed to the output shaft 1 of the electric motor m. Further, a ring-shaped mounting plate 3 made of a conductive material such as stainless steel having a hole formed in the center is fixed to the fixing means a by a screw member n1, and a cylindrical bearing made of a conductive material is attached to the mounting plate 3. The holder 4 is fixed with a screw member n2.
A cylindrical rotary body 5 made of a conductive material is inserted into the cylindrical bearing holder 4, and a pair of ball bearings 6 and 7 and a bearing collar 8 are provided between the rotary body 5 and the bearing holder 4. The rotary body 5 is rotatably supported with respect to the bearing holder 4 by being interposed.

The ball bearings 6 and 7 have a sealing function to keep the space surrounded by the bearing holder 4 airtight. The ball bearings 6 and 7 thus configured are fixed between the bearing holder 4 and the fixing structure is as follows.
A stop step 5a is formed at a position corresponding to the tip of the bearing holder 4 in the rotary body 5, and one ball bearing 6 is fixed to the stop step 5a. The other ball bearing 7 is fixed by a bearing pressing plate 9 which is a rotary body 5 and is fixed to a surface facing the mounting plate 3. The bearing pressing plate 9 is fixed to the rotary body 5 by a plurality of screw members n3 fixed in the circumferential direction.

  As is clear from the above, the pair of ball bearings 6 and 7 are firmly held between the stopping step 5a and the bearing retainer plate 9 while maintaining a certain distance with the bearing collar 8, and the bearing holder The pressure fluid in the space formed in 4 is prevented from leaking outside.

Further, in the rotary main body 5, a rotary gear 10 is fixed to an outer periphery adjacent to the one ball bearing 6, and the rotary gear 10 is engaged with a drive gear 2 fixed to the electric motor m.
Reference numeral n4 in the drawing denotes a screw member that is inserted into the rotary gear 10 through the flange portion 5b formed in the rotary body 5.
Since it comprised as mentioned above, if the electric motor m is driven and the drive gear 2 is rotated, the rotational force of this drive gear 2 will be transmitted to the rotary main body 5 via the rotation gear 10, and the rotary main body 5 It will rotate relative to the bearing holder 4.

  The fluid passage 5c is penetrated through the rotary body 5. The center of one opening 5d is made coincident with the rotation center axis of the rotary body 5, and the center of the other opening 5e is made the center of rotation of the rotary body 5. It is eccentric with respect to the shaft. Therefore, when the rotary body 5 rotates, the other opening 5e moves circularly around the rotation center axis.

Further, the central hole portion of the mounting plate 3 is communicated with the one opening 5d, and the tip portion of the first hollow body 11 made of a conductive material is inserted into the central hole of the mounting plate 3. Yes. And the flange part 11a is formed in the outer periphery of this 1st hollow body 11, this flange part 11a is stuck to the said attachment board 3, and is fixed with the screw member n5. The axial center line of the first hollow body 11 fixed to the attachment plate 3 in this way is made to coincide with the rotational center axis of the rotary body 5.
In the figure, reference numeral 12 denotes a ground wire connected to the first hollow body 11.

Further, the pressing member 13 is fixed to the side surface of the mounting plate 3 opposite to the insertion direction of the first hollow body 11 by a screw member n6. The pressing member 13 holds a ceramic support plate 14 between the first hollow body 11 inserted into the attachment plate 3 and the distal end portion thereof. The support plate 14 is a member for supporting a second conductive pipe 15 described later at the center of the first and second hollow bodies 11 and 17.
The first hollow body 11 configured as described above is screw-coupled to the second hollow body 17 via a connecting member 16 that is screw-coupled to the end opposite to the mounting plate 3. 17 and the connecting member 16 constitute a hollow body of the present invention. The connecting member 16 and the second hollow body 17 are made of a resin that is an insulating material, and are electrically insulated from the first hollow body 11.

A cylindrical member 19 constituting a casing 18 made of a conductive material is fixed to the rotary body 5 on the other opening 5e side. That is, a flange portion 19 a is formed around the opening of the cylindrical member 19, and the cylindrical member 19 is fixed to the rotary body 5 by a screw member n 7 that passes through the flange portion 19 a. When the cylindrical member 19 is fixed to the rotary main body 5 as described above, the opening of the cylindrical member 19 coincides with the other opening 5e.
A ceramic support plate 20 is sandwiched between the cylindrical member 19 and the rotary body 5. The support plate 20 has a pipe support hole formed at the center thereof, and a flow hole through which a pressure fluid flows is formed around the pipe support hole.

Further, the distal end of the cylindrical member 19 is screwed to a throttle cylinder member 21 constituting the casing 18 via a screw portion 21a. A cylindrical cap member 22 is screwed to the distal end of the throttle cylinder member 21 via a screw portion 22a (see FIG. 2).
A first conductive pipe 23 is led to a casing 18 composed of the cylindrical member 19, the throttle cylinder member 21, and the cap member 22. The first conductive pipe 23 is a pipe support of the support plate 20. While being supported by the hole, the base end side is supported by a support hole 24a of a ceramic support plate 24 fitted and fixed to one opening 5d of the fluid passage 5c (see FIG. 4). Further, as shown in FIG. 4, the support plate 24 is formed with a plurality of flow holes 24b through which the pressure fluid flows.

Further, as shown in FIG. 2, a swirl flow generating means 25 made of an insulating material is fitted into the cylindrical member 19, and the outer periphery thereof is fixed with a set screw b <b> 1 penetrating the cylindrical member 19. The tip end portion of the first conductive pipe 23 is supported by the pipe support hole 25a formed in the swirling flow generating means 25, and the tip end of the first conductive pipe 23 protrudes from the swirling flow generating means 25. Yes.
In addition, a space in which the pressure fluid flows is formed between the first conductive pipe 23 and the fluid passage 5 c and between the first conductive pipe 23 and the casing 18. However, the spiral flow generating means 25 is formed with a spiral hole 25b penetrating therethrough so that when the pressure fluid passes through the spiral hole 25b, the fluid passing through the spiral flow generating means 25 becomes a swirl flow. I have to.

In FIG. 2, reference numeral 26 denotes an O-ring fitted in an annular recess 23 a formed on the outer periphery of the first conductive pipe 23, provided in contact with the swirl flow generating means 25, and the first conductive pipe 23. The gap between the outer circumference of the pipe and the pipe support hole 25a of the swirling flow generating means 25 is sealed. By sealing this gap, the pressure fluid supplied to the casing is surely passed through the spiral hole 25b.
As described above, the cylindrical discharge electrode 27 made of tungsten is screwed to the tip of the first conductive pipe 23 protruding from the swirling flow generating means 25 via the screw portion 27a. The first conductive pipe 23 and the discharge electrode 27 can be separated as necessary by loosening screws. Therefore, when the discharge electrode 27 is consumed by discharge, it can be easily replaced with a new discharge electrode.

Further, a tungsten earth ring 28 constituting an earth electrode is fitted with a screw 21b formed on the inner periphery of the tip of the aperture cylinder member 21, and a jig is inserted into the jig recess 28a. The earth ring 28 can be attached to and detached from the aperture cylinder member 21 by tightening or loosening a screw.
The earth ring 28 configured as described above is electrically connected to the earth wire 12 through the casing 18, the rotary body 5, the ball bearing 7, the bearing holder 4, the mounting plate 3, and the first hollow body 11. .

A through hole 28b having an inner diameter larger than the outer diameter of the discharge electrode 27 is formed in the center of the earth ring 28, and the tip of the discharge electrode 27 is inserted into the through hole 28b. The front end surface 27b and the opening surface 28c of the through hole 28b are flush with each other.
Since the first conductive pipe 23 is held at the center position of the casing 18 by the support plate 20 and the swirl flow generating means 25, the discharge electrode 27 connected thereto is also positioned at the center of the casing 18, A constant gap is maintained between the through hole 28b and the discharge electrode 27.
Therefore, if a high voltage is applied to the discharge electrode 27, a discharge occurs between the discharge electrode 27 and the earth ring 28.

Further, an annular convex portion 22b is formed in the cap member 22 constituting the casing 18, but between the annular convex portion 22b and the tip opening of the cap member 22, as shown in FIG. An insulating plate 29, a conductive plate 30, and a web washer 31 which are jet outlet constituent members of the present invention are provided in order from the tip opening toward the inside.
A predetermined distance is maintained between the conductive plate 30 and the tip end surface 27b of the discharge electrode 27, and the straight flow flowing out from the discharge electrode 27 and the swirl flow formed by the swirl flow generating means 25 are merged. A merge chamber 22c is formed.

The insulating plate 29 is attached by being screwed to a screw portion formed inside the tip opening of the cap member 22 and is made of an insulating material such as ceramic.
The insulating plate 29 is passed through three flow holes 29a, and these flow holes 29a are arranged at the apex positions of equilateral triangles as shown in FIG. The center of this equilateral triangle is made to coincide with the center of the insulating plate 29.
Further, as shown in the schematic diagrams of FIGS. 2 and 7, each of the flow holes 29 a has an opening diameter d <b> 2 on the side in close contact with the conductive plate 30, which is larger than the opening diameter d <b> 1 on the side opposite to the conductive plate 30. It is getting bigger.

On the other hand, the conductive plate 30 is a tungsten disk, and the through holes 30a are respectively passed through the insulating plates 29 at positions facing the through holes 29a. The opening diameter d3 of each flow hole 30a of the conductive plate 30 is formed substantially equal to the opening diameter d1 and is smaller than the opening diameter d2 of the flow hole 29a of the insulating plate 29.
By screwing the insulating plate 29 to the cap member 22, the conductive plate 30 is fixed between the insulating plate 29 and the annular protrusion 22 b, and each flow hole 29 a of the insulating plate 29 and each of the conductive plate 30 are fixed. The circulation hole 30a is made continuous.
In this embodiment, the flow holes 29 a and 30 a are not formed at the centers of the conductive plate 30 and the insulating plate 29. As will be described later, when a pressure fluid is ejected from the discharge electrode 27, a linear flow composed of the ejected pressure fluid is preferentially ejected from the circulation hole 29a formed at the center, and the other fluid holes 29a This is to prevent a difference between the two.

Further, a web washer 31 is sandwiched between the conductive plate 30 and the annular convex portion 22b, and the spring force prevents rattling between the insulating plate 29 and the conductive plate 30, and the conductive plate 30 and the cap. The electrical connection with the member 22 is also ensured.
Since the cap member 22 is connected to the throttle cylinder member 21 grounded by the ground wire 12 connected to the first hollow body 11 as described above, the conductive plate 30 is also grounded. Together with the earth ring 28, the earth electrode of the present invention is constituted. Accordingly, when a high voltage is applied to the discharge electrode 27, a discharge is also generated between the discharge electrode 27 and the conductive plate 30.
1 and 2 are nuts for adjusting the position of the cap member 22.

  Further, the first conductive pipe 23 screwed to the discharge electrode 27 is a pipe bent from the center of the casing 18 so as to pass through the center of the fluid passage 5c as shown in FIG. The proximal end of the first conductive pipe 23 is connected to the second conductive pipe 15 so as to be relatively rotatable as will be described in detail later (see FIGS. 1 and 4).

FIG. 4 shows an enlarged view of the connection structure of the first and second conductive pipes 23 and 15 that are connected so as to be relatively rotatable.
As shown in FIG. 4, a large-diameter portion 15a is formed at the tip of the second conductive pipe 15, and the outer periphery of the large-diameter portion 15a is screwed to a connecting nut 33 made of a conductive material.
Further, the first conductive pipe 23 is inserted into the connection nut 33, and a ball bearing 34 having a sealing function is interposed between the first conductive pipe 23 and the connection nut 33.

Reference numeral 35 in the figure denotes a C-ring fitted into an annular recess 23b formed at the rear end of the first conductive pipe 23. The C-ring 35 is a stopping step 23c formed in the first conductive pipe 23. The ball bearing 34 is held between the first and second conductive pipes 23 and the ball bearing 34 is prevented from coming off.
Then, the first conductive pipe 23 and the second conductive pipe 15 rotate relative to each other in a state in which their rotation centers are matched. At this time, the center of the opening of the first and second conductive pipes 23 and 15 and the rotation center axis of the rotary body 5 are made to coincide.
Under the above structure, the first and second conductive pipes 23 and 15 are electrically connected via the connection nut 33 and the ball bearing 34.

A ball bearing 36 is provided on the outer periphery of the connecting nut 33, and a bearing holder 37 made of an insulating material is fixed to the outer periphery of the ball bearing 36 with a set screw b2. Further, the bearing holder 37 is screwed onto the support plate 24. It is fixed with member n8.
By configuring as described above, the connection nut 33 is substantially supported by the support plate 24 so as to be relatively rotatable. Thus, the connection nut 33 is supported by the support plate 24, so that the center of the connection nut 33 portion does not shake.

Further, since the opening center of the second conductive pipe 15 coincides with the rotation center axis of the rotary main body 5, even if the rotary main body 5 rotates and the first conductive pipe 23 rotates, The second conductive pipe 15 does not move circularly. Therefore, when the rotary body 5 rotates, the second conductive pipe 15 and the pipe connected to the second conductive pipe 15 are not twisted.
Moreover, since the second electric pipe 15 is also supported by the support plate 14, even if the rotary main body 5 rotates, it can always maintain a stable state.
The support plate 14 is also a plate member made of ceramic, like the support plates 20 and 24, and includes a support hole that penetrates and supports the second conductive pipe 15 and a circulation hole that circulates fluid. .

  On the other hand, as shown in FIG. 5, mounting holes 17b, 17c, and 17d are formed on the bottom surface 17a of the second hollow body 17, and the mounting hole 17c is connected to a pressure fluid source (not shown). A hose nipple 38 is attached. The rear end of the second conductive pipe 15 and the front end of the hose nipple 38 are connected by a high-pressure connection socket 39 formed of an insulating material such as glass epoxy. The high-pressure connection socket 39 is formed with a threaded portion 39a over the entire length of the inner wall of the cylinder, and the small diameter portion 15b formed at the rear end of the second conductive pipe 15 and the tip of the hose nipple 38 are screwed together. doing.

In FIG. 5, reference numeral 40 denotes a hose that connects the hose nipple 38 and the joint 41, and the joint 41 is connected to the pressure fluid source via a hose 42.
The joint 41 is also connected to a hose nipple 44 attached to the attachment hole 17d via the hose 43.
The joint 41 configured as described above allows the pressure fluid guided from the pressure fluid source to be branched and guided to the hose 40 or to the hose 43.

The pressure fluid led to the hose 40 is supplied from the second conductive pipe 15 to the discharge electrode 27 via the first conductive pipe 23 and is jetted out as a straight flow from the tip opening of the discharge electrode 27.
On the other hand, the pressure fluid guided to the hose 43 is supplied into the second hollow body 17. As described above, the pressure fluid supplied into the second hollow body 17 passes through the connecting member 16, the first hollow body 11, and the fluid passage 5 c in the rotary body 5 and is supplied into the casing 18. The pressurized fluid supplied into the casing 18 passes through the spiral hole 25b of the swirl flow generating means 25 and forms a swirl flow downstream thereof, that is, on the outer periphery of the discharge electrode 27.

The second hollow body 17 is provided with a metal high-voltage power supply plate 45, a central hole 45a is formed at the center thereof, and the small diameter portion 15b of the second conductive pipe 15 is passed through the central hole 45a. Yes. The high voltage power supply plate 45 is brought into contact with the step formed by the small diameter portion 15 b, and the high voltage power supply plate 45 is sandwiched between the step and the high voltage connection socket 39 together with the spring washer 46. .
The high voltage power supply plate 45 has an outer diameter smaller than the inner diameter of the second hollow body 17 so that the outer periphery does not contact the second hollow body 17. The high voltage power supply plate 45 is formed with a plurality of flow holes 45b through which a fluid passes. The flow holes 45b and a space formed outside the high voltage power supply plate 45 are combined with each other in the second hollow body 17. A flow path for the supplied pressure fluid is formed.

Furthermore, a screw is formed on the inner periphery of the mounting hole 17b, and a cylindrical connector 48 for mounting a high voltage cable 47 connected to a high voltage source (not shown) is screwed. The connector 48 includes a bottom surface 48 a formed with a through hole through which the high voltage cable 47 passes.
In the connector 48, a cable guide 49 made of an insulating material into which the tip of the high voltage cable 47 is inserted and an O-ring 50 are inserted.

The cable guide 49 is provided with a spring chamber 49a having a large inner diameter on the distal end side, and a metal compression coil spring 51 is incorporated therein. The compression coil spring 51 is connected to the tip of the high-voltage cable 47 at one end, and maintains electrical continuity with the high-voltage cable 47.
The other end of the compression coil spring 51 is opposed to the portion of the high voltage power supply plate 45 where the flow hole 45b is not formed. As a result, the tip of the compression coil spring 51 is pressed against and contacts the high voltage power supply plate 45 by elastic force, and the high voltage cable 47 and the high voltage power supply plate 45 can be kept in an electrically conductive state stably.

As described above, the high voltage cable 47 connected to a high voltage source (not shown) is electrically connected to the second conductive pipe 15 through the high voltage power supply plate 45, and the second conductive pipe 15 is connected to the above as shown in FIG. The first conductive pipe 23 is electrically connected via the connection socket 33 and the ball bearing 34, and the first conductive pipe 23 is electrically connected to the discharge electrode 27 by screw connection as shown in FIG.
Therefore, a high voltage is applied to the discharge electrode 27 by a high voltage source connected to the high voltage cable 47.

As shown in FIG. 5, the high-voltage cable 47 has its distal end in contact with the high-voltage power supply plate 45 via the compression coil spring 51, so that the second hollow can be obtained simply by removing the connector 48. The high voltage cable 47 can be easily removed from the body 17. For example, if the tip of the high-voltage cable 47 is soldered or screwed to the high-voltage power supply plate 45 or the second conductive pipe 15, it takes time to remove or attach it. In this embodiment, the high voltage cable 47 can be easily attached and detached.
Also, the pressure fluid supply hoses 40 and 43 can be easily removed at the hose nipples 38 and 44.

  As described above, since the high voltage cable 47 and the hoses 40 and 43 can be easily attached and detached, the apparatus main body can be easily separated from the high voltage source and the pressure fluid source. In particular, since the ion generation apparatus of this embodiment includes a rotation drive mechanism that rotates the casing 18, it may be necessary to perform maintenance on a location related to the rotation drive mechanism. Sexuality also improves.

In the ion generator of this embodiment, when a high voltage is applied to the discharge electrode 27, a discharge occurs between the discharge electrode 27, the earth ring 28, and the conductive plate 30, and ions are generated in the casing 18. (See FIG. 7).
Further, the pressure fluid supplied from the pressure fluid source becomes a swirl flow around the discharge electrode 27 together with a straight flow that is jetted from the tip of the discharge electrode 27, and these are merged in the merge chamber 22 c and the cap member 22. The ions generated inside are ejected as an ion stream.

Of the pressure fluid, the swirl flow formed around the discharge electrode 27 stirs the ions generated near the tip of the discharge electrode 27 to generate a uniform ion space in the cap member 22. Demonstrate the function to do.
Such a swirl flow alone does not allow a sufficient amount of ions to be discharged to the outside of the casing 18 because the transfer force in the straight direction along the axis line is reduced as in the conventional device. In the ion generating apparatus, since the discharge electrode 27 has a pipe shape and is a fluid passage, the straight flow caused by the pressure fluid ejected from the tip of the discharge electrode 27 draws the swirling ions and propels it in the axial direction. It is thought to add power.

As a result, ions generated in the vicinity of the discharge electrode 27 can be reliably sent out from the casing 18 to the outside as an ion stream.
The ion flow ejected from the ion generating device can be ejected further while maintaining the ion concentration by the merge of the swirl flow and the straight flow.

An experiment for confirming the performance of the ion generator of this embodiment will be described with reference to FIG.
FIG. 6 (a) uses the ion generator of the above embodiment, and the output of the high voltage source is 500 W, and the pressure fluid source is air with a flow rate of 150 [L / min] and a pressure of 0.5 [MPa]. Shows the experimental results when the hose is supplied to the two hoses 40 and 43 (see FIG. 5) via the hose. That is, in this experiment, a straight air flow direction indicated by an arrow α and a swirl flow indicated by an arrow β formed by the swirl flow generating means 25 are generated in the cap member 22 from the discharge electrode 27. , These are merged.

As a result, as shown in FIG. 6A, it was confirmed by visual observation that ion flows were similarly ejected from all three flow holes 29a.
In this ion generator, the swirling flow (arrow β) stirs the ion space generated in the vicinity of the discharge electrode, so that ions are uniformly spread into the confluence chamber 22c of the cap member 22 and ejected from the discharge electrode 27. It is considered that the ion flow is ejected from all the flow holes 29a by the straight flow (arrow α) that pulls in and moves forward.
In this embodiment, since the flow holes 29a and 30a are not formed in the center of the conductive plate 30 and the insulating plate 29, the straight flow from the discharge electrode 27 is directly discharged from the flow holes 30a and 29a to the outside. It is considered that the ions generated near the tip of the discharge electrode 27 were efficiently drawn and the ion flow was ejected from all the flow holes 29a evenly.

On the other hand, when the pressure fluid is not supplied to the hose 40 but is supplied only to the hose 43, that is, in the experiment in which only the swirl flow (arrow β) is generated, the ion flow is as shown in FIG. It was confirmed that the liquid was slightly ejected from only one flow hole 29a. In this experiment, the output of the high voltage source is 500 [W] and the supply flow rate to the hose 43 is 150 [L / min].
From this experiment, it is expected that only the above-described swirl flow (arrow β) lacks the straight-forward force for ejecting ions forward.

The reason why the ion flow ejected only from the specific flow hole 29a can be confirmed is as follows.
In this experiment, some of the ions swirling by the swirling flow (arrow β) also ride on the swirling flow toward the flow holes 30a and 29a, but the amount of ions reaching the flow holes 29a only by the swirling flow is a straight flow. It is thought that there are few compared with the case where it merges. For this reason, when the ion flow is ejected first from the flow hole 29a on the upstream side in the swirl flow, it can be expected that only the pressure fluid containing no ions is ejected from the other flow holes 29a.

  Further, in the case where only the hose 40 is supplied without supplying the pressure fluid to the hose 43, that is, in the experiment in which only the straight flow (arrow α) is generated, as shown in FIG. The ejection of the ion flow could not be confirmed visually from the circulation hole 29a. Also in this experiment, the output of the high voltage source is 500 [W], and the supply flow rate to the hose 40 is 150 [L / min].

As described above, even if the air flow is ejected from the pipe-shaped discharge electrode 27, if there is no swirling flow (arrow β) around the discharge electrode 27, the reason why the ion flow is not ejected is as follows. Think like that.
Since ions are generated by a discharge generated between the discharge electrode 27 and the earth ring 28, the ions exist in a ring shape around the discharge electrode 27. On the other hand, the air flow ejected from the discharge electrode 27 is a straight flow that passes through the center of the ion space distributed in the ring shape, and it is assumed that this straight flow alone has insufficient function of entraining ions. it can.

As described above, the ion generation apparatus according to the above-described embodiment combines a plurality of ion jets by combining the straight flow jetted from the center of the pipe-shaped discharge electrode 27 and the swirl flow formed around the discharge electrode 27. An ion stream can be stably ejected from the outlet.
Moreover, the ion generator of this embodiment can rotate the rotary main body 5 with the said electric motor m. When the rotary body 5 rotates, the casing 18 fixed at a position eccentric from the rotation center axis of the rotary body 5 performs a circular motion around the rotation center axis. As a result, the ion jet port moves circularly, and the jet range of the ion flow can be substantially widened.

In addition, since the first and second hollow bodies 11 and 17 are attached to the rotary main body 5 so as to be relatively rotatable, the first and second hollow bodies 11 and 11 can be rotated even if the rotary main body 5 rotates. 17 can be fixed without rotating. Therefore, the fluid supply hoses 40 and 43 and the high voltage cable 47 attached to the second hollow body 17 are not twisted.
In addition, since the opening center of the second conductive pipe 15 coincides with the rotation center axis and is connected to the first conductive pipe 23, the second conductive pipe 15 is rotated even if the first conductive pipe 23 rotates. The conductive pipe 15 does not move circularly. As described above, since the second conductive pipe 15 does not move circularly, the inner diameters of the first and second hollow bodies 11 and 17 provided with the second conductive pipe 15 need to be increased corresponding to the radius of the circular movement. The apparatus can be made compact.

In the above embodiment, the insulating plate 29 and the conductive plate 30 are stacked in the cap member 22, and the flow hole 29 a of the insulating plate 29 and the flow hole 30 a of the conductive plate 30 constitute an ion jet outlet. Yes. The insulating plate 29 is positioned on the downstream side of the conductive plate 30 with respect to the flow direction of the pressure fluid.
By arranging the insulating plate 29 and the conductive plate 30 in this manner, the ion flow ejected from the ion ejection port can be further stabilized over a long period of time.

The reason will be described with reference to FIG.
When a high voltage is applied to the discharge electrode 27, a main discharge is generated between the earth ring 28 and the tip of the discharge electrode 27. However, since the conductive plate 30 is also connected to the ground, the discharge electrode 27 A discharge toward the conductive plate 30 is also generated. By providing such a conductive plate 30, the ion space becomes large, and ions can be generated efficiently. Therefore, in order to efficiently generate ions, it is effective that the conductive plate 30 that constitutes the ion ejection port constitutes a ground electrode.

  On the other hand, when the generated ions pass through the flow hole 30a as an ion flow by the pressure fluid, the metal conductive plate 30 is damaged by the ions. When such ion damage is received, the circulation hole 30a is consumed by ions, and the opening diameter d3 of the circulation hole 30a is increased, or the direction of the circulation hole 30a is bent. When the flow hole 30a is deformed in this manner, the direction and speed of the pressure fluid that passes through and is ejected changes. Actually, the direction of the fluid changes and the flow velocity drops, so that the target ion flow is not ejected.

However, in the above embodiment, as shown in FIG. 7, an insulating plate 29 such as ceramic is disposed downstream of the flow hole 30a, and the flow hole 29a is connected to the flow hole 30a. The direction and flow velocity of the ion flow ejected from 30 a are corrected by the flow holes 29 a of the insulating plate 29.
Since the insulating plate 29 made of ceramic is not subjected to ion damage like the conductive plate 30, the flow hole 29a is not deformed even if the ion flow passes. Therefore, even if the flow hole 30a of the conductive plate 30 is deformed due to ion damage and the direction of the ion flow is slightly changed, the flow can be corrected and ejected by the flow hole 29a of the insulating plate 29.
In particular, since the upstream opening diameter d2 of the flow hole 29a is made larger than the opening diameter d3 of the flow hole 30a of the conductive plate 30, the ion flow ejected from the flow hole 30a of the conductive plate 30 is surely insulated. 29 flow holes 29a.

Further, when the deformation amount of the flow hole 30a of the conductive plate 30 increases due to ion damage, the conductive plate 30 must be replaced. When the insulating plate 29 is not provided on the downstream side of the conductive plate 30, the conductive plate 30 has to be replaced in one to two weeks. However, the insulating plate 29 is provided even in the same usage situation. As a result, it has become possible to use it for more than one year. That is, providing the insulating plate 29 can substantially extend the life of the conductive plate 30.
Note that tungsten, molybdenum, and the like that form the conductive plate 30 are materials that are less susceptible to ion damage than other metals such as stainless steel, but are more expensive than other metal materials. By providing the insulating plate 29, it is meaningful to extend the life of such expensive parts.

  Furthermore, in the above embodiment, since the insulating plate 29 is screwed to the cap member 22 and the conductive plate 30 is simply pressed against the annular convex portion 22b by the insulating plate 29, the cap member 22 and the conductive plate 30 are No screw connection is required. If the conductive plate 30 made of tungsten and the cap member 22 made of stainless steel are screw-coupled, the screw-coupled portion between the different metals is discharged as the discharge to the conductive plate 30 is repeated. There is a possibility of welding due to heat. If this happens, the conductive plate 30 and the cap member 22 are integrated, and the conductive plate 30 cannot be removed from the cap member 22 and replaced, so the entire cap member 22 must be replaced. In the configuration of the above embodiment, only the conductive plate 30 can be replaced.

  The ion generator of the present invention can be used for various surface treatments using ions.

18 Casing 27 Discharge electrode 28 Earth ring 29 Ground plate 29 Insulating plate 29a Flow hole 30 Conductive plate 30a Flow hole

Claims (2)

A casing connected to a pressure fluid source and provided with an ion outlet;
A discharge electrode provided in the casing for applying a high voltage;
An earth electrode for discharging between the discharge electrode and
With
Ions are generated by applying a high voltage to the discharge electrode and discharging between the ground electrode,
An ion generator for ejecting the ions from the ion ejection port,
The ion spout is
A plurality of flow holes are formed, and a conductive plate constituting the ground electrode;
A plurality of flow holes are formed, and an insulating plate made of an inorganic material provided on the downstream side of the conductive plate with respect to the outflow direction of the pressure fluid supplied from the pressure fluid source,
While making the said conductive plate and the front end surface of the said discharge electrode oppose,
An ion generating apparatus configured to eject the ions by the pressure fluid passing through the flow hole of the conductive plate and the flow hole of the insulating plate.   The opening diameter of the insulating plate that is in close contact with the conductive plate is larger than the opening diameter of the insulating plate that is opposite to the conductive plate and the opening diameter of the through hole that is formed in the conductive plate. The ion generating apparatus according to claim 1, which is also enlarged.

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