JP4958271B2 - Discharge electrode unit of ionizer - Google Patents

Description

  The present invention relates to static electricity control in the air or static elimination of a work, and more particularly to a discharge electrode unit of an ionization apparatus used for static electricity control or static elimination of a work.

  Conventionally, ionizers that generate ions by applying a high voltage to the discharge electrode have a problem that the dust contained in the atmospheric gas adheres to the tip of the discharge electrode and the static elimination speed decreases. In relation to this problem, Patent Document 1 discloses a discharge electrode unit of an ionization apparatus. In the discharge electrode unit, the tip of the discharge electrode protrudes from the center hole and a clean gas is ejected, and the ions are transported to the object to be discharged while the ambient gas is taken in by the clean gas.

  According to this discharge electrode unit, since the tip of the discharge electrode is surrounded by the clean gas, it is possible to reduce the contamination of the discharge electrode over time. The gas can be entrained and the ions can be conveyed toward the work (electric charge removal object) with the combined gas flow having a sufficient flow rate, thereby achieving an advantage that a high charge removal speed can be achieved.

JP 2006-40860 A

  However, it goes without saying that even with the discharge electrode unit disclosed in Patent Document 1, it is not possible to completely prevent dust from accumulating at the tip of the discharge electrode to which a high voltage is applied. On the other hand, since the atmospheric gas is involved to generate the ion transport flow, there is a possibility that the dust contained in the atmospheric gas is likely to adhere to the tip of the discharge electrode. For this reason, as disclosed in Patent Document 1, it is necessary to devise a method for removing a part of the sharp tip of the discharge electrode.

  An object of the present invention is to provide a discharge electrode unit that can suppress contamination of the tip of the discharge electrode, which becomes a problem when the amount of gas in the ion carrier flow is increased by entraining atmospheric gas.

According to the present invention, such a technical problem is
Having a raised head portion and a finger guard disposed around the head portion;
The finger guard has a peripheral window through which atmospheric gas can flow into the finger guard in a side region of the head part, and an opening opened forward of the raised head part,
In the center hole of the raised head portion, a tip of the discharge electrode for applying a high voltage is disposed in a state of protruding to the outside, and a clean gas is discharged around the discharge electrode. A discharge electrode unit of an ionization apparatus that conveys ions generated by the discharge electrode to the object to be discharged through the opening while taking in atmospheric gas flowing through the surrounding window,
This is achieved by providing a discharge electrode unit in which the raised head portion is made of a resin containing a fiber, and a part of the fiber is exposed from the tapered surface of the raised head portion. .

  That is, according to the discharge electrode unit of the present invention, a part of the fiber is exposed on the taper surface of the raised head portion that guides the atmospheric gas entrained in the clean gas surrounding the tip portion of the discharge electrode, and is microscopic. Since a part of the fiber protrudes in a whisker shape from the tapered surface, dust in the atmospheric gas can be captured by this fiber. Furthermore, according to the present invention, since the protrusion or groove is formed on the taper surface, this can generate disturbance in the atmosphere gas flowing along the taper surface, thereby increasing the frequency with which the atmosphere gas contacts the taper surface. Therefore, the efficiency of capturing the dust in the atmospheric gas described above can be increased. As a result, it is possible to suppress the contamination of the tip of the discharge electrode and to suppress the decrease in the amount of ion generation over time. In addition, the rigidity of the head part can be increased by configuring the head part with a resin containing a fiber, and when the fiber is composed of a flame-retardant fiber such as a glass fiber, the flame retardancy and insulation properties are increased. It is possible to provide an excellent head part. This means that it becomes a preferable physical property as a head portion surrounding a discharge electrode to which a high voltage is applied.

  Hereinafter, discharge electrode units according to embodiments will be described in detail with reference to the accompanying drawings.

  FIG. 1 is a diagram for explaining an internal structure of an ionization device (static elimination device) to which the discharge electrode unit of the embodiment is applied, and FIG. 2 is a perspective view showing an outer shape of the ionization device as a specific example. The ionization apparatus 100 has a case 10 having an inverted U-shaped cross section with the upper end closed, and a gas passage 12 including a plurality of gas passage units 11 is disposed in a lower region inside the case 10. 11, a plurality of discharge electrodes 13 are spaced apart from each other.

  In the upper region of the case 10, a high voltage box 14 containing a high voltage unit and a control unit 15 including a power supply circuit, for example, a display device and a CPU are arranged. Clean gas ports 16 are provided at both ends in the longitudinal direction of the case 10, and clean gas is supplied to the gas passage 12 from a gas source not shown through the clean gas ports 16.

  The clean gas introduced into the gas passage unit 11 through the clean gas port 16 is, for example, an inert gas such as nitrogen gas, or a clean gas made of filtered air from which moisture is removed by filtering dust in the atmosphere, preferably further A clean gas from which organic compounds have been removed can be mentioned.

  The discharge electrode 13 is incorporated in the discharge electrode unit 200 as will be described later, and the discharge electrode 13 is incorporated into the ionization apparatus 100 by mounting the discharge electrode unit 200 on the case 10. 1 and 2, reference numeral 17 denotes a partition wall that partitions the inside of the case 10 up and down, and 18 denotes a connection terminal for a modular connector that connects adjacent ionizers 100 together. Reference numeral 19 denotes a grounded counter electrode plate. The counter electrode plate 19 substantially constitutes a part of the case 10, and the lower opening of the case 10 is closed by the counter electrode plate 19.

  FIG. 3 is a diagram showing an outline of a control circuit of the ionization apparatus 100. The ionization apparatus 100 employs a pulsed AC ion generation system so that positive ions and negative ions are alternately generated from the same discharge electrode 13. The control circuit of the ionization apparatus 100 includes a plus-side high voltage generation circuit 30 and a minus-side high voltage generation circuit 31, and the high voltage generation circuits 30 and 31 incorporate a high voltage box 14 (FIG. 1). A voltage unit is configured.

  Both the positive side high voltage generation circuit 30 and the negative side high voltage generation circuit 31 are self-excited oscillation circuits 34 and 35 connected to the primary side coils of the transformers 32 and 33, and, for example, doubled connected to the secondary side coil. And booster circuits 36 and 37 each including a rectifier circuit. A protective resistor, that is, a first resistor R <b> 1 is provided between the high voltage generation circuits 30 and 31 and the discharge electrode 13.

  A second resistor R2 and a third resistor R3 are connected in series between the ground terminal GND of the secondary coil of the transformers 32 and 33 and the frame ground FG. Further, the counter electrode plate 19 and the frame ground FG The fourth resistor R4 and the third resistor R3 described above are connected in series.

  By detecting the current flowing through the fourth resistor R4 by the ion current detection circuit 38, the ion balance in the vicinity of the discharge electrode 13 can be known. By detecting the current flowing through the third resistor R3 by the ion current detection circuit 38, the ion balance in the vicinity of the workpiece or the charged object can be known. By detecting the current flowing through the second resistor R2 by the abnormal discharge current detection circuit 39, the abnormal discharge between the discharge electrode 13 and the counter electrode plate 19 or the frame ground FG can be detected. When the determination is made, the operator can be informed of the abnormality by turning on the display LED 40 as an alarm means.

  The control circuit of the ionization apparatus 100 employing the pulsed AC type ion generation method has been described above. However, the AC method in which positive ions and negative ions are alternately generated at a commercial current frequency, or positive ions and negative ions are generated simultaneously. The SSDC method may be adopted, or the pulse DC method in which positive ions and negative ions are alternately generated may be adopted.

  4 and subsequent drawings are diagrams relating to the discharge electrode unit 200. FIG. 4 is a side view of the discharge electrode unit 200, FIG. 5 is a plan view of the discharge electrode unit 200, FIG. 6 is a longitudinal sectional view taken along line VI-VI in FIG. 5, and FIG. FIG. 7 is a longitudinal sectional view taken along line VII-VII in FIG. 5. 4 to 7, the discharge electrode unit 200 includes a hollow shaft portion 202 and a head portion 204 provided at the tip of the shaft portion. The shaft portion 202 includes the discharge electrode 13. Is inserted and a gas passage is formed around the discharge electrode 13. Since the basic structure of the discharge electrode unit 200 and the power supply path to the discharge electrode 13 are substantially the same as the discharge electrode unit disclosed in JP-A-2006-40860 (Japanese Patent Application No. 2004-337216), While detailed description is omitted, the disclosure of Japanese Patent Application No. 2004-337216 is incorporated herein.

  In the discharge electrode unit 200, a seal member 206 made of an elastic material such as rubber is fitted between the shaft portion 202 and the head portion 204, as indicated by a virtual line in FIG.

  As can be understood from FIGS. 4, 6, and 7, the head portion 204 has an outer contour that protrudes toward the top of the center, and the tip of the discharge electrode 13 is inserted into the top of the tapered surface 208. A circular center hole 210 is formed. In the example shown in the figure, the outer shape has a substantially conical bulge, but a substantially pyramid shape may be used instead. That is, the raised outline of the head portion 204 has a substantially cone shape.

  The head unit 204 includes a finger guard 212 that surrounds the tip of the discharge electrode 13. The finger guard 212 has a circumferentially continuous ring 214 that is spaced apart in front of the tapered surface 208 and a plurality of legs 216 that connect between the ring 214 and the outer peripheral edge of the tapered surface 208. The plurality of leg portions 216 are spaced apart from each other in the circumferential direction of the ring 214, and a peripheral window 218 for introducing external air is formed between the adjacent leg portions 216 and 216. Since the finger guard 212 is a guard member for preventing the finger from touching the tip 13a of the discharge electrode 13 when the discharge electrode unit 200 is replaced, for example, the ring 214 has an opening 214a formed thereby. As long as it has, it may be discontinuous in the circumferential direction.

  The clean gas supplied into the discharge electrode unit 200 through the clean gas passage 12 (FIG. 1) inside the ionizer 100 is introduced into the hollow shaft portion 202 and hollowed through the circular central hole 210 at the tip of the hollow shaft portion 202. It is discharged in the axial direction of the shaft portion 202. As described above, the distal end portion of the discharge electrode 13 passes through the central hole 210 and is exposed to the outside. Therefore, the central hole 210 is a clean gas jet port that is circumferentially continuous around the discharge electrode 13. Form. Since the negative pressure is generated in the vicinity of the center hole 210 by the clean gas discharged from the center hole 210 of the hollow shaft portion 202, the atmospheric gas flows into the finger guard 212 through the peripheral window 218 described above, and the tapered surface 208. In this way, it is combined with the clean gas and discharged to the outside through the opening 214a of the finger guard 212 as a transport flow for transporting ions.

  The discharge electrode unit 200 is a plastic molded product, and at least the head portion 204 is made of a resin containing a fiber. Preferably, short fiber is included, and the type of fiber is generally glass fiber. As a result, the rigidity, flame retardancy, and insulation of the head portion 204 can be improved, and when the discharge electrode unit 200 is molded from a resin containing such short fiber fibers, the surface of the tapered surface 208 of the head portion 204 is obtained. Thus, a part of the fiber having a diameter of 10 μm or less is exposed, and dust in the atmospheric gas flowing into the finger guard 212 can be captured by the exposed fiber. When it is assumed that the head portion 204 is injection-molded, the fiber content is preferably 30 to 40% by weight in order to ensure moldability.

  As the resin, it is preferable to select a resin excellent in insulating properties, and it is preferable to select a resin excellent in flame retardancy. For example, thermosetting resins (for example, phenol resins and epoxy resins) are generally excellent in rigidity and flame retardancy. On the other hand, thermoplastic resins (for example, polyethylene and polystyrene) are excellent in terms of flame retardancy and moldability. However, thermosetting resins are generally inferior in moldability compared to thermoplastic resins. As described above, since the resin has various characteristics, a resin considered to be preferable for the head portion 204 may be arbitrarily selected. When, for example, polystyrene is selected, which is excellent in moldability and flame retardancy, it is not only easy to ensure the required rigidity by mixing the glass fiber described above, but also flame retardancy and insulation properties. Furthermore, it can be made preferable. Of course, it goes without saying that a carbon fiber may be used instead of the glass fiber. However, when a carbon fiber is employed, it is preferable to reduce the content ratio compared to glass fiber in order to ensure insulation.

  As shown in FIG. 5 and the like, a plurality of circumferential grooves 220 having different diameters are formed around the center hole 210 on the tapered surface 208 of the head portion 204. The circumferential groove 220 may be formed by cutting after the discharge electrode unit 200 is molded. In general, however, the circumferential groove 220 is molded together when the discharge electrode unit 200 is molded. Is good. In the example shown in the figure, the protrusions or grooves 220 extending continuously in the circumferential direction are circular, but they may have a shape extending in a corrugated manner. The cross-sectional shape of the protrusions or grooves 220 may be rectangular, semicircular, or triangular. In addition, the height or depth of the protrusions or grooves 220 is generally several μm to several hundred μm.

  In the illustrated example, the tapered surface 208 has an inclination angle of the inner peripheral portion 208b larger than that of the outer peripheral portion 208a. Accordingly, the distance in which the atmospheric gas flows along the tapered surface 208 can be increased, the flow direction of the atmospheric gas can be guided toward the work (electric charge removal body), and the atmospheric gas can be discharged to the discharge electrode 13. It can suppress contacting with the front-end | tip part 13a. Further, the protruding position of the tip 13a (generally a sharp tip) of the discharge electrode 13 is set in relation to the intersection CP of the tangent line extending in the vertical direction along the inner peripheral portion 208b (FIG. 8). Specifically, in order to ensure good ion generation efficiency, the tip 13a of the discharge electrode 13 is preferably positioned between the opening end of the center hole 210 and the intersection CP.

  By applying a high voltage to the discharge electrode 13 while ejecting a clean gas from the center hole 210 of the head portion 204, the atmospheric gas flowing into the finger guard 212 through the peripheral window 218 of the finger guard 212 is entrained and discharged to the discharge electrode 13. A clean gas is discharged from around the area, whereby ions are supplied toward the workpiece (electric charge removal body).

  The ambient gas flowing into the finger guard 212 through the peripheral window 218, that is, the peripheral window 218 between the two adjacent legs 216 and 216, flows along the tapered surface 208 toward the center hole 210 of the head portion 204. Then, it will merge with the clean gas discharged from the center hole 210. As described above, the head portion 204 is made of a resin including at least a fiber exposed to the outside from the surface of the head portion 204. When the head portion 204 is injection-molded, a microscopic effect is obtained when the fiber is randomly included so as to have the above-described weight content (30 to 40%) with respect to the base resin material such as polystyrene. In particular, it is possible to form a state in which a part of the fiber protrudes like a whisker on the tapered surface 208 of the head portion 204. As a result, dust contained in the atmospheric gas can be captured. The diameter of the fiber is preferably 10 μm or less.

  As best seen in FIG. 8, the tapered surface 208 crosses the circumferential groove 220 extending in the direction intersecting with the flow direction of the atmospheric gas. The circumferential groove 220 may be a circumferential protrusion, but the presence of the circumferential groove (circumferential protrusion) 220 causes a disturbance in the flow of the atmospheric gas flowing along the tapered surface 208, thereby The frequency with which the gas contacts the tapered surface 208 increases.

  As described above, the head portion 204 is made of a resin including a short fiber, and microscopically, the tapered surface 208 is in a state in which a part of the fiber is exposed on the surface and protrudes like a beard. Therefore, dust contained in the ambient gas can be captured by this fiber, and in particular, the capture efficiency is enhanced by the circumferential groove (or circumferential projection) 220 extending in the direction intersecting the flow of the ambient gas. As a result, it is possible to suppress the adhesion and accumulation of dust and the like on the tip exposed to the outside of the discharge electrode 13, and to suppress a decrease in ion generation efficiency over time. Needless to say, this means that the replacement time of the discharge electrode 13 can be extended.

  In the above-described example, an example in which the circumferential groove (or circumferential projection) 220 is formed on the tapered surface 208 of the head portion 204 has been described. However, dust is captured by the circumferential groove (or circumferential projection) 220 in the head portion 204. If there is no need to increase the effect, the circumferential groove (or circumferential projection) 220 may be omitted from the tapered surface 208 of the head portion 204.

  The drawings after FIG. 9 exemplify a modification regarding the shape or arrangement of a recess or a protrusion in place of the above-described circumferential groove (circumferential protrusion) 220. FIG. 9 shows an example in which discontinuous grooves or protrusions 222 are provided in the circumferential direction. In the illustrated example, discontinuous arc-shaped or substantially rectangular grooves or projections 222 are provided on the circumference of three rows having different diameters, but the number of rows is arbitrary, and the grooves or projections 222 are staggered. It may be disposed, or may be provided only on the inner peripheral portion or the outer peripheral portion of the tapered surface 208.

  In FIG. 10, the circular grooves or protrusions 224 are arranged in a circumferential shape of three rows having different diameters, but the number of rows is arbitrary, and the circular grooves or protrusions 224 may be arranged in a staggered manner. Alternatively, it may be provided only on the inner peripheral portion or the outer peripheral portion of the tapered surface 208. Further, the arc-shaped or substantially rectangular groove or protrusion 222 illustrated in FIG. 9 may be mixed. In addition, the circular groove or protrusion 224 may be oval or elliptical in shape.

  FIG. 11 shows an example in which protrusions or grooves 226 are intermittently arranged in a spiral shape. In order to arrange the plurality of protrusions or grooves 226 in a spiral shape, in the example of FIG. 11, the protrusions or grooves 226 having a rectangular shape with different lengths are illustrated. It may be a circle, an ellipse, or an ellipse. Moreover, as shown in FIG. 12, the protrusion or groove | channel 228 which continues in a spiral shape may be sufficient. In FIG. 12, the spirally continuous protrusions or grooves 228 extend in a curved shape, but may have a waveform extending in a wave shape.

  In the above description, the surrounding window 218 between the adjacent legs 216, 216 may be an open surrounding window where nothing exists as shown, or the ambient gas can be freely passed, eg, comparison It may have a net-like configuration with a large stitch, and may have a fence-like structure. In the design of the finger guard 212, it is desirable to suppress the projected area occupied by each leg 216 and set the total area of the surrounding window 218 large.

  As described above, the head portion 204 made of resin including a short fiber is covered with the clean gas ejected from the same central hole 210 so that the tip of the discharge electrode 13 protruding from the central hole 210 is covered with the discharge electrode 13. Not only can the contamination of the tip be suppressed, but also by providing protrusions or grooves 228, 220, etc. on the tapered surface 208 that guides the flow of the atmospheric gas, dust contained in the atmospheric gas can be actively captured. As a result, the contamination of the tip of the discharge electrode 13 can be further suppressed, so that the replacement time of the discharge electrode 13 can be extended while preventing the ionization efficiency from decreasing with time.

  In the above-described embodiment, the clean gas is injected from the same central hole 210 from which the discharge electrode 13 protrudes to the outside. Of course, the clean gas is injected from a hole different from the hole from which the discharge electrode 13 protrudes. Needless to say.

  In the above-described embodiment, the head portion 204 and the finger guard 212 are integrally formed by injection molding. However, the head portion 204 and the finger guard 212 are separately injection-molded and joined in a later process. May be. In the injection molding, when the head part 204 and the finger guard part 212 are formed integrally or separately, the resin melting temperature is generally set to 280 ° C to 290 ° C. Is preferably set to a melting temperature further increased by 10 ° C.

  The method of forming the head portion 204 and the finger guard 212 separately and combining them in the subsequent process includes (1) concavo-convex fitting, (2) ultrasonic welding, (3) screwing, and (4) adhesive. Not only can bonding be used, but also a method in which the individually molded head portion 204 and finger guard 212 are loaded into a mold and resin is poured into these bonding portions for bonding. May be.

It is a figure for demonstrating the structure of the ionization apparatus of the Example of this invention. It is a perspective view which shows the external shape of the ionization apparatus of an Example. It is a circuit diagram of the ionization apparatus of an Example. It is a side view of the discharge electrode unit provided in the ionization apparatus so that replacement | exchange is possible. It is a front view of a discharge electrode unit. It is a longitudinal cross-sectional view along the VI-VI line of FIG. It is a longitudinal cross-sectional view along the VII-VII line of FIG. It is a figure for demonstrating the preferable protrusion amount of the front-end | tip of the discharge electrode of a discharge electrode unit. It is a figure for demonstrating the 1st modification of the processus | protrusion or groove | channel formed in the protruding taper surface of a discharge electrode unit, and is a figure shown in the state which planarly viewed the taper surface. It is a figure for demonstrating the 2nd modification of the processus | protrusion or groove | channel formed in the protruding taper surface of a discharge electrode unit, and is a figure shown in the state which planarly viewed the taper surface. It is a figure for demonstrating the 3rd modification of the processus | protrusion or groove | channel formed in the taper surface which the discharge electrode unit protruded, and is a figure shown in the state which planarly viewed the taper surface. It is a figure for demonstrating the 4th modification of the processus | protrusion or groove | channel formed in the taper surface which the discharge electrode unit protruded, and is a figure shown in the state which planarly viewed the taper surface.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 Ionizer 200 Discharge electrode unit 202 Hollow shaft part 204 Head part 208 The taper surface of the outline outline which protruded in the substantially conical shape 210 Circular center hole 212 Finger guard 218 Surrounding window (for atmospheric gas introduction)
220 Circumferential groove

Claims (6)

Having a raised head portion and a finger guard disposed around the head portion;
The finger guard has a peripheral window through which atmospheric gas can flow into the finger guard in a side region of the head part, and an opening opened forward of the raised head part,
In the center hole of the raised head portion, a tip of the discharge electrode for applying a high voltage is disposed in a state of protruding to the outside, and a clean gas is discharged around the discharge electrode. A discharge electrode unit of an ionization apparatus that conveys ions generated by the discharge electrode to the object to be discharged through the opening while taking in atmospheric gas flowing through the surrounding window,
The discharge electrode unit, wherein the raised head part is made of a resin containing a fiber, and a part of the fiber is exposed from a tapered surface of the raised head part. The discharge electrode unit according to claim 1 , wherein a groove or a protrusion that disturbs the flow of the atmospheric gas flowing along the tapered surface is formed on the tapered surface of the raised head portion.   The discharge electrode unit according to claim 2, wherein the groove or the protrusion has a shape extending in a direction intersecting with the flow of the atmospheric gas flowing along the inclined direction of the tapered surface.   The discharge electrode unit according to any one of claims 1 to 3, wherein a tip of the discharge electrode is positioned between an intersection of tangents extending in the vertical direction of the tapered surface and the center hole.   The discharge electrode unit according to any one of claims 1 to 4, wherein the clean gas is injected from the center hole. A substantially cone-shaped head portion having a central hole for discharging clean gas at the top;
A discharge electrode protruding outward from the central hole;
An ionization device having a finger guard provided around a tip of the discharge electrode and having an opening in front of the discharge electrode;
The finger guard extends in a direction away from the head portion and is spaced apart from each other in the circumferential direction of the tip portion, and atmospheric gas is introduced into the finger guard between two adjacent legs. A surrounding window that can flow in,
Grooves or protrusions extending in a direction intersecting the gas flow of the atmospheric gas flowing into the finger guard through the peripheral window are formed on the inclined surface of the substantially cone-shaped head portion ,
The discharge electrode unit, wherein the substantially cone-shaped head portion is made of a resin containing a fiber, and a part of the fiber is exposed from an inclined surface of the substantially cone-shaped head portion .

Images