JP5092716B2 - Ion generator - Google Patents

Description

  The present invention relates to an ion generator, and more particularly to an ion generator that generates ions by discharge between a discharge needle electrode and a ground electrode.

Patent Document 1 discloses a static eliminator having a cover in which a plurality of discharge needle electrodes are protruded at predetermined intervals in the longitudinal direction, and an open portion is provided on the protruding side of the discharge needle electrode. This cover has a surface resistivity of 10 ⁷ Ω / mm ² or less.

The cover prevents the fingertip from coming into contact with the discharge needle electrode. In order to make the surface resistivity of the plastic cover as an insulator 10 ⁷ Ω / mm ² or less, a surface active agent or the like is used. Must be applied to the surface of the cover. However, there has been a problem that the surface active agent is deteriorated due to a change with time, the surface resistivity is changed, the release of ions is reduced, and the static elimination ability is lowered.
JP 2005-142131 A

  Accordingly, an object of the present invention is to provide an ion generator capable of efficiently generating and releasing ions without causing a change with time.

In order to achieve the above object, an ion generator according to the present invention comprises:
In an ion generator containing a discharge needle electrode and an ion generating element having a ground electrode facing the discharge needle electrode in a case,
The case includes a cover having an opening facing the discharge needle electrode,
The cover is made of a conductive material, is grounded via a limiting resistor, has an opening ratio of 50% or more, and a thickness of 0.5 mm or less .
It is characterized by.

  When an opening is formed in the cover in order to release ions to the outside, if the cover is made of an insulating material, the opening is likely to be charged and ions are retained, which inhibits the generation of new ions. Further, when the cover made of a conductive material is simply grounded without passing through the limiting resistor, the generated ions are almost absorbed by the cover, and the release of ions is suppressed. In the ion generator according to the present invention, since the cover is formed of a conductive material and grounded through a limiting resistor, charging of the cover is suppressed and ions are appropriately absorbed, so that ions are generated efficiently. Further, by providing the limiting resistor, the leakage current with the ion generating element is reduced, and the generation of ozone can be suppressed.

In the ion generator according to the present invention, the limiting resistor preferably has a resistance value of 1 M to 2 GΩ. Generally, an insulator has a resistance value of 10 ¹⁵ Ω or more, and a conductor has a resistance value of 10 ⁶ Ω or less. By setting the resistance value from the limiting resistance to the cover to preferably about 10 ⁷ to 10 ¹² Ω, ions can be absorbed to the extent that they do not accumulate in the opening. The resistance value of the limiting resistor is preferably variable, and the amount of ion generation can be adjusted.

  The cover is preferably formed of a metal material. The metal material has little change over time and has good durability. In particular, stainless steel is preferred as a cover material because it is resistant to oxidation, has excellent durability and processability, and is inexpensive. Further, the cover may be in a lattice shape, and the lattice shape has high mechanical strength and good durability, and can effectively prevent the fingertip from touching the ion generating element. The cover preferably has a high aperture ratio and a small thickness in order to reduce ion absorption. In order to suitably suppress the absorption of ions, it is preferable that the opening ratio of the cover is 50% or more and the thickness is 0.5 mm or less.

  The ion generator according to the present invention may include a positive ion generating element that generates positive ions and a negative ion generating element that generates negative ions. In this case, it is preferable that the positive ion generating element and the negative ion generating element are accommodated in one case. Since the positive ion generating element and the negative ion generating element are accommodated in one case, the electric field strength is increased and the amount of generated ions is increased.

  According to the present invention, the cover having an opening that discharges ions generated by the discharge is formed of a conductive material and grounded through the limiting resistor, so that the opening is prevented from being charged and the cover appropriately receives ions. Since it absorbs, there is no stagnation of ions, ions can be generated and released efficiently, and the amount of released ions does not decrease with time.

  Embodiments of an ion generator according to the present invention will be described below with reference to the accompanying drawings. In each figure, common parts and portions are denoted by the same reference numerals, and redundant description is omitted.

(Refer 1st Example and FIGS. 1-10)
As shown in FIGS. 1 and 2, the ion generator 10 according to the first embodiment of the present invention has an ion generating element 20 accommodated in a case 11, and the case 11 has a cover 15 on the front surface. ing. As shown in FIG. 3, the ion generating element 20 is provided with a high voltage electrode 22 and a ground electrode 23 on an insulating substrate 21, and the ground electrode 23 is covered with an insulating film 24 except for the electrode portion 23a. The insulating substrate 21 has a cutout recess 21 a, and a linear discharge needle electrode 25 is provided in the recess 21 a in a state of being electrically connected (soldered) to the high-voltage electrode 22.

  The discharge needle electrode 25 is a very thin wire, and a piano wire, a tungsten wire, a stainless steel wire, a titanium wire, or the like is used, and is disposed between the distal arm portions 23 b of the ground electrode 23. A high voltage is applied to the discharge needle electrode 25 from the high voltage electrode 22, and the ground electrode 23 is dropped from the electrode portion 23a to the ground.

  Such an ion generating element 20 can generate negative ions or positive ions by applying a negative or positive high voltage to the discharge needle electrode 25. That is, when a negative or positive voltage is applied to the discharge needle electrode 25, a strong electric field is formed between the discharge needle electrode 25 and the tip arm portion 23b of the ground electrode 23, and a dielectric breakdown occurs in the vicinity of the tip portion of the discharge needle electrode 25. Then, a corona discharge state occurs, and negative or positive ions are generated. In this example, negative ions were generated by applying a negative voltage.

  As shown in FIG. 2, the ion generating element 20 is installed in the case 11 with the tip of the discharge needle electrode 25 facing the cover 15. The generated ions are released to the outside from the lattice-like openings 16 formed in the cover 15 as indicated by arrows in FIG.

  The cover 15 is made of a conductive material such as stainless steel or copper, and the openings 16 have a lattice shape as shown in FIG. Specifically, it was formed with a stainless steel having a thickness of 0.15 mm and an aperture ratio of 87.8%. The vertical and horizontal dimensions are 20 mm, the width of the outer frame is 2 mm, and the width of each of the five grids is 0.2 mm. Further, the cover 15 is dropped from the electrode portion 17 to the ground via the limiting resistor 18. The resistance value of the limiting resistor 18 is set to 2 MΩ in the first embodiment.

  In this ion generator 10, since the cover 15 is formed of a conductive material and grounded via the limiting resistor 18, charging of the cover 15 is suppressed, and the cover 15 absorbs ions appropriately, so that the ion generating element Ions are efficiently generated from 20 and the amount of ions released from the opening 16 increases. In addition, by providing the limiting resistor 18, the leakage current in the ion generating element 20 is reduced, and the generation of ozone can be suppressed.

  The inventor measured the amount of ions generated in the ion generator 10 of the first embodiment using the ion measuring apparatus shown in FIG. A metal plate 41 was installed at a position where the distance D2 from the ion generator 10 was 30 mm. An ampere meter 42 is inserted in the measurement circuit.

  Using the above ion measuring device, the ampere meter 42 measured the ionic current flowing through the metal plate 41 while changing the voltage applied to the ion generating element 20 from −3 kV to −7 kV. The measurement object is the first example provided with a 2 MΩ limiting resistor 18 and Comparative Example 1 in which the limiting resistor 18 is omitted and the cover 15 is directly grounded with the same configuration.

  The result is shown in FIG. In FIG. 6, the horizontal axis represents the voltage applied to the ion generating element 20, and the vertical axis represents the ion current flowing through the metal plate 41. Curve a shows the ionic current in the first example, and curve b shows the ionic current in Comparative Example 1. As is apparent from the comparison between the curves a and b, in the first embodiment in which the limiting resistor 18 is inserted, many ions are generated and released. In Comparative Example 1 in which the limiting resistor 18 is omitted, most of the ions generated by the ion generating element 20 are absorbed by the cover 15 and the amount of ions released is suppressed.

(Refer 2nd Example and FIGS. 7-11)
In the second embodiment of the present invention, as shown in FIG. 7, a positive ion generator 10A and a negative ion generator 10B are juxtaposed, and an ion generating element that generates positive ions and an ion generating element that generates negative ions. Is accommodated in each case 11. The distance D3 between the cases 11 is 10 mm, and the distance between the two discharge needle electrodes 25 is 30 mm. As described above, by arranging the ion generators 10A and 10B in parallel, the electric field strength of each ion generating element is increased, and the amount of ions generated is increased.

  Next, the static elimination effect was experimented using the measuring apparatus shown in FIG. The applied voltages to the discharge needle electrode 25 are +5 kV and −5 kV, respectively. The charging plate 30 placed at a distance D1 (30 mm) from the ion generating element 20 was charged to +12 kV, the charge removal state was measured with the charged voltage measuring device 31, and the time (sec) was measured. The charging plate 30 is connected to a DC high-voltage power source DC of 12 kV through a discharge resistor Rd of 330Ω, a charge resistor Rc of 1 MΩ, and a switch SW. The intermediate point between the resistors Rd and Rc is connected to the discharge return terminal T via the energy storage capacitor Cs.

  FIG. 9 shows the experimental results, where the vertical axis represents the charging voltage of the charging plate 30 and the horizontal axis represents the time (sec) required for static elimination. In addition to the experiment in the second embodiment, Comparative Example 1 in which only the limiting resistor 18 is omitted in the same configuration, Comparative Example 2 in which the cover 15 is not grounded in the same configuration, and the cover is made of a Teflon (registered trademark) grid. The experiment was also performed in Comparative Example 3 in which an opening was formed and in Comparative Example 4 having a cover in which a lattice-shaped opening was formed with polypropylene.

  In FIG. 9, a curve c shows the charge removal effect of the second embodiment. Curve d shows the charge removal effect of Comparative Example 1, curve e shows the charge removal effect of Comparative Example 2, curve f shows the charge removal effect of Comparative Example 3, and curve g shows the charge removal effect of Comparative Example 4. The steeper the curve, the faster the static elimination speed and the more ions are generated and released. As is apparent from FIG. 9, the second embodiment (curve c) exhibits the most preferable static elimination effect. In Comparative Examples 3 and 4 (curves f and g) using an insulator for the cover, the cover is charged and generation of ions is suppressed. Even if the cover 15 is made of metal as in Comparative Example 2 (curve e), the generation of ions is similarly suppressed unless the cover 15 is grounded. In Comparative Example 1 (curve d), as described above, most of the ions are absorbed by the cover 15 and the amount of ions released is suppressed.

  Further, in the ion generators 10A and 10B according to the second embodiment using the measuring apparatus shown in FIG. Experiments on the static elimination effect were conducted by setting each to 3 GΩ. An outline of the results is shown in FIG. 10, where the vertical axis indicates the time during which the charging plate 30 can be neutralized to 2 kV, and the horizontal axis indicates the distance D1 between the ion generating element and the charging plate 30 (see FIG. 8). The voltages applied to the ion generating elements were +5 kV and -5 kV, respectively.

  In FIG. 10, a curve h indicates a case where the resistance value is 0Ω, and a curve i indicates a case where the resistance value is 1 MΩ, 3 MΩ, and 3 GΩ. Curve j represents a resistance value of 2 GΩ, curve k represents a resistance value of 1 GΩ, and curve l represents a resistance value of 100 MΩ, 200 MΩ, and 500 MΩ. As is apparent from the results, a preferable charge removal speed was obtained when the resistance value of the limiting resistor 18 was set to 1 M to 3 GΩ, and a more preferable charge removal speed was obtained particularly at 100 M to 2 GΩ.

Incidentally, the resistance value of the insulator is 10 ¹⁵ Ω or more, and the resistance value of the conductor is 10 ⁶ Ω or less. In the ion generator 10, the resistance value from the limiting resistor 18 to the cover 15 is preferably about 10 ⁷ to 10 ¹² Ω, and the cover 15 can absorb ions to the extent that they do not accumulate in the opening. Further, the resistance value of the limiting resistor 18 may be variable, and the ion generation amount can be adjusted.

  Regarding the cover 15, the metal material is preferable in that it hardly changes over time and has good durability, and in particular, stainless steel can be suitably used. By forming the cover 15 in a lattice shape, the mechanical strength is high, the durability is good, and the fingertip can be effectively prevented from touching the ion generating element.

  The cover 15 preferably has a high aperture ratio and a small thickness in order to reduce ion absorption. So far, experiments have been conducted with the ion generator 10 using the cover 15 having a thickness of 0.15 mm and an aperture ratio of 87.8%. Here, for comparison, FIG. 11 shows an experimental result of the charge removal effect in Comparative Example 5 provided with a cover having a thickness of 0.9 mm and an aperture ratio of 33%. FIG. 11 is an experiment using the measuring apparatus shown in FIG. 8. In FIG. 11, the vertical axis represents the charging voltage of the charging plate 30, and the horizontal axis represents the time (sec) required for static elimination.

  In FIG. 11, the curve m shows the charge removal effect of the second embodiment, the curve n shows the charge removal effect of the comparative example 5, and the cover 15 is preferably thin and has a high aperture ratio. The cover 15 preferably has an opening ratio of 50% or more and a thickness of 0.5 mm or less.

  The purpose of providing the cover 15 is to prevent the fingertip from touching or approaching the discharge needle electrode 25 and receiving an electric shock. If the distance between the tip of the discharge needle electrode 25 and the cover 15 or the case 11 is set to a potential difference of 1 kV / mm or less, the discharge needle electrode 25 and the cover 15 can be insulated, and the cover 15 can be approached or touched. There is no electric shock.

(Refer to the third embodiment, FIG. 12)
In the third embodiment of the present invention, as shown in FIG. 12, a positive ion generating element and a negative ion generating element are accommodated in one case 11. The case 11 is provided with a cover 15a facing the positive ion generating element and a cover 15b facing the negative ion generating element. The covers 15a and 15b may be formed integrally.

  When the positive ion generating element and the negative ion generating element are accommodated in one case 11 as in the third embodiment, the discharge needle is more than in the case of being accommodated in a separate case 11 as in the second embodiment. The distance between the electrodes is shortened (in the third embodiment, the distance between the discharge needle electrodes is 20 mm), and the electric field strength in each ion generating element is increased. Thereby, each ion generation amount becomes larger.

(Other examples)
In addition, the ion generator which concerns on this invention is not limited to the said Example, It can change variously within the range of the summary.

  For example, various shapes other than the shape shown in FIG. 4 can be employed as the opening shape of the cover. For example, the shape shown in FIG. The detailed configuration and shape of the ion generating element are arbitrary, and an AC voltage may be superimposed on the DC voltage for the generation of ions.

1 is a perspective view showing a first embodiment of an ion generator according to the present invention. It is sectional drawing of 1st Example. An ion generating element is shown, (A) is a perspective view, (B) is a top view. It is a front view which shows the opening shape formed in the cover. It is explanatory drawing which shows an ion measuring apparatus. It is a graph which shows the ion current of 1st Example and Comparative Example 1 measured by the said ion measuring apparatus. It is a perspective view which shows 2nd Example of the ion generator which concerns on this invention. It is a block diagram which shows the measuring apparatus for measuring a static elimination effect. It is a graph which shows the static elimination effect of 2nd Example and Comparative Examples 1-4. It is a graph which shows the static elimination effect at the time of changing the resistance value of a limiting resistance variously. It is a graph which shows the static elimination effect of 2nd Example and Comparative Example 5. It is a perspective view which shows 3rd Example of the ion generator which concerns on this invention. It is a front view which shows the other opening shape of a cover.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10, 10A, 10B ... Ion generator 11 ... Case 15, 15a, 15b ... Cover 16 ... Opening part 18 ... Limiting resistor 20 ... Ion generating element 23 ... Ground electrode 25 ... Discharge needle electrode

Claims (9)

In an ion generator containing a discharge needle electrode and an ion generating element having a ground electrode facing the discharge needle electrode in a case,
The case includes a cover having an opening facing the discharge needle electrode,
The cover is made of a conductive material, is grounded via a limiting resistor, has an opening ratio of 50% or more, and a thickness of 0.5 mm or less .
An ion generator characterized by.   The ion generator according to claim 1, wherein the limiting resistor has a resistance value of 1 M to 2 GΩ. The ion generator according to claim 1, wherein a resistance value from the limiting resistor to the cover is about 10 ⁷ to 10 ¹² Ω.   4. The ion generator according to claim 1, wherein the limiting resistor has a variable resistance value.   The ion generator according to claim 1, wherein the cover is made of a metal material.   The ion generator according to claim 5, wherein the cover is made of stainless steel.   The ion generator according to claim 1, wherein the cover has a lattice shape. The ion generator according to any one of claims 1 to 7 , further comprising: a positive ion generating element that generates positive ions; and a negative ion generating element that generates negative ions. 9. The ion generator according to claim 8 , wherein the positive ion generating element and the negative ion generating element are accommodated in one case.

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