JP5734924B2 - Ion generator and discharge electrode mounting state monitoring method - Google Patents

Description

  The present invention relates to an ion generator and a discharge electrode mounting state monitoring method.

  When performing static elimination for cleaning in a clean room or preventing the floating particles from being charged, a corona discharge type ion generator is often used (see Patent Document 1).

  In this type of ion generating apparatus, the state of corona discharge of the discharge electrode may deteriorate due to dust accumulation on the discharge electrode or wear of the electrode due to long-term use.

  When the state of corona discharge of the discharge electrode deteriorates, the current flowing through the ground electrode (counter electrode) decreases. For example, Patent Document 2 proposes a technique for notifying the abnormality of corona discharge when there is a decrease in the electrode flowing in the counter electrode.

Japanese Patent No. 4829503 Japanese Patent No. 2816667

  By the way, many ion generators can attach and detach a discharge electrode to an electrode mounting part for maintenance and inspection. When there is dust accumulation or electrode wear on the discharge electrode during maintenance and inspection, operations such as cleaning and replacement of the discharge electrode are performed.

  However, since the discharge electrode can be attached and detached, when the discharge electrode is replaced, the attachment of the discharge electrode to the electrode mounting portion may be incomplete. In such a case, there is a possibility that the discharge electrode falls off due to impact.

  In some cases, the discharge electrode is not attached to the electrode mounting portion due to forgetting to attach the discharge electrode during maintenance inspection. And when the discharge electrode is removed from the electrode mounting portion, the ion generation capability of the ion generation device is significantly reduced.

  Therefore, when a state occurs in which the discharge electrode is detached from the electrode mounting portion due to dropping or forgetting to attach the discharge electrode (hereinafter, sometimes referred to as “an abnormal mounting state”), dust on the discharge electrode is generated. Unlike the state in which the accumulation of the electrode or the wear of the discharge electrode is occurring (hereinafter sometimes referred to as “the state of dust accumulation or the like”), it is highly necessary to immediately detect the occurrence of the abnormal mounting state and take measures.

  However, in the conventional method as disclosed in Patent Document 2, it has not been possible to detect an “attachment abnormal state” due to a dropout of a discharge electrode or forgetting to attach a discharge electrode to distinguish it from a “dust accumulation state” or the like. . For this reason, even if dust accumulates on the discharge electrode or wear of the discharge electrode occurs, the ion generator must be inspected frequently, or conversely, if an abnormal mounting condition of the discharge electrode occurs. There is an inconvenience that measures against the situation are delayed.

  The present invention has been made in view of such a problem, and an abnormal state (attachment abnormal state) in which the discharge electrode has been detached from the electrode mounting portion due to dropping of the discharge electrode or forgetting to attach the discharge electrode is disclosed. It is an object of the present invention to provide an ion generation device and a discharge electrode mounting state monitoring method that can be distinguished from abnormal states (dust accumulation state) such as dust accumulation on the electrode or electrode wear.

The ion generator of the present invention generates a corona discharge from the discharge electrode by alternately applying positive and negative high voltages to the discharge electrode attached to the electrode attachment portion via the electrode attachment portion. In an ion generating device that generates air ions by discharge, a detection electrode disposed opposite to the discharge electrode, and the detection electrode and the grounding portion are electrically connected between the detection electrode and the grounding portion. An impedance circuit for outputting a voltage signal having a waveform corresponding to a current flowing between the impedance circuit and a detection means for receiving the voltage signal output from the impedance circuit, wherein the detection means is a positive or negative high voltage. Is applied to the discharge electrode to generate a determination signal indicating a magnitude relationship between the magnitude of the voltage signal output from the impedance circuit and a predetermined threshold value. The threshold value is the voltage signal output from the impedance circuit in a state where the high voltage is applied to the electrode mounting portion under the condition that the discharge electrode is not mounted to the electrode mounting portion. When the discharge voltage is equal to or lower than the threshold value and the discharge electrode is normally attached to the electrode attachment part, a high voltage equal to the high voltage for the electrode attachment part is applied to the discharge. a state of being applied to the electrodes, and, in a state in which the corona discharge from the discharge electrode upon application of the high voltage is not generated, the magnitude of the peak value of the voltage signal outputted from the impedance circuit is greater than said threshold value It is set so that it may become (the 1st invention).

  The impedance circuit means a circuit composed of one or more circuit elements having impedance, such as a resistance element and a capacitance element.

  The positive and negative high voltages applied to the discharge electrodes are not limited to sinusoidal voltages but may be pulsed voltages.

  The same applies to other inventions described later.

  Here, through the experiments and examinations of the inventors of the present application, by setting the threshold appropriately, an abnormality such that the discharge electrode is detached from the electrode mounting portion due to the discharge electrode being dropped or the discharge electrode being forgotten to be attached, etc. It was found that the state (abnormal mounting state) can be distinguished from the abnormal state (dust accumulation state) such as dust accumulation or electrode wear on the discharge electrode.

  That is, the positive or negative high to the electrode mounting part in an abnormal state (such as dust accumulation) in which the discharge electrode is normally attached to the electrode mounting part and dust is accumulated on the discharge electrode or the discharge electrode is worn. The magnitude of the voltage signal output from the impedance circuit in response to the application of a voltage is normally such that a positive or negative high voltage is applied to the electrode mounting portion although the discharge electrode is normally attached to the electrode mounting portion. This is equal to or greater than the magnitude of the voltage signal in a state where no corona discharge occurs due to (hereinafter referred to as “no discharge state when a high voltage is applied”).

  On the other hand, the voltage signal output from the impedance in response to the application of a positive or negative high voltage to the electrode mounting portion in the “attachment abnormal state” due to the discharge electrode being dropped or forgetting to attach the discharge electrode. Is smaller than the magnitude of the voltage signal in the “no discharge state when a high voltage is applied”.

Therefore, in the first invention, the threshold value is output from the impedance circuit in a state where the high voltage is applied to the electrode mounting portion under the condition that the discharge electrode is not mounted on the electrode mounting portion. Under the condition that the magnitude of the peak value of the voltage signal is equal to or less than the threshold value and the discharge electrode is attached to the electrode attachment portion, a high voltage equal to the high voltage for the electrode attachment portion is set. The voltage signal output from the impedance circuit has a peak value greater than the threshold value when applied to the discharge electrode and no corona discharge is generated from the discharge electrode when the high voltage is applied. It set so that it might become large.

  In other words, in the first invention, the threshold value is equal to or larger than the peak value of the voltage signal in the “mounting abnormality state” and the peak value of the voltage signal in the “no discharge state when high voltage is applied”. It set so that it might become a value less than this.

  Therefore, according to the first aspect of the present invention, the occurrence of the “abnormal mounting state” is generated based on the determination signal output from the detection means indicating the magnitude relationship between the threshold value set as described above and the magnitude of the voltage signal. , And can be detected promptly in distinction from the occurrence of a “dust accumulation state”. For example, when the determination signal of the detection means indicates that the magnitude of the voltage signal output from the impedance circuit in response to the application of a positive or negative high voltage to the discharge electrode is equal to or less than a threshold value, It can be determined that "an abnormal mounting state" is occurring instead of "a dust accumulation state".

  In the ion generating apparatus according to the first aspect of the present invention, a plurality of the discharge electrodes and at least one of the detections facing at least one group of N discharge electrodes (N: an integer of 2 or more) among the plurality of discharge electrodes. It is preferable that one or more of the detection electrodes facing the N discharge electrodes are connected to a single impedance circuit (second invention).

  According to the second aspect of the invention, since a single impedance circuit can be shared for N discharge electrodes, it is possible to simplify an ion generation device that can detect the occurrence of an “attachment abnormality state”, and the ion generation device. The cost can be reduced.

  In the second invention, the detection electrodes opposed to the N discharge electrodes may be a plurality of detection electrodes respectively opposed to the N discharge electrodes.

  In the ion generating apparatus according to the first or second invention, when the determination signal is a signal indicating that the magnitude of the voltage signal is equal to or less than the threshold value, an abnormal attachment state of the discharge electrode has occurred. An alarm is output (third invention).

  When the determination signal is a signal indicating that the value of the voltage signal is equal to or less than the threshold value, as described above, it corresponds to a case where the “mounting abnormality state” has occurred. Therefore, according to the third aspect of the present invention, when the voltage signal becomes equal to or lower than the threshold value, an alarm indicating that the abnormal state of mounting of the discharge electrode has occurred is output, thereby preventing the occurrence of the “abnormal mounting state” from occurring. Can be notified.

  In the ion generator according to the third aspect of the present invention, when the determination signal is a signal indicating that the magnitude of the voltage signal is equal to or less than the threshold value, application of a high voltage to the electrode mounting portion is cut off. It is preferable that this is done (fourth invention).

  When the determination signal is a signal indicating that the value of the voltage signal is equal to or less than the threshold value, as described above, it corresponds to a case where the “mounting abnormality state” has occurred. Therefore, according to the fourth aspect of the invention, when the voltage signal falls below the threshold value, an alarm is output that an abnormal state of mounting of the discharge electrode has occurred, and the application of a high voltage to the electrode mounting portion is cut off. By doing so, the operation of the ion generating apparatus in the “attachment abnormal state” can be promptly stopped.

  The ion generators according to the first to third aspects of the present invention may include a counter electrode disposed in the vicinity of the discharge electrode so as to face the discharge electrode in order to generate a corona discharge. In that case, the detection electrode and the counter electrode may be provided separately.

  However, the detection electrode may be arranged so as to function as a counter electrode that generates corona discharge between the opposing discharge electrodes (fifth invention).

  According to the fifth aspect of the invention, the number of parts of the ion generating device can be reduced because the detection electrode also functions as the counter electrode. Therefore, it is possible to simplify the configuration of the ion generation device that can detect the occurrence of the “abnormal mounting state” and to reduce the cost of the ion generation device.

The discharge electrode attachment state monitoring method of the present invention generates corona discharge from the discharge electrode by alternately applying positive and negative high voltages to the discharge electrode attached to the electrode attachment portion via the electrode attachment portion. In the ion generating apparatus that generates air ions by the corona discharge, a method for monitoring the mounting state of the discharge electrode, wherein an electric current is provided between the detection electrode disposed opposite to the discharge electrode and the grounding portion. In response to applying a positive or negative high voltage to the discharge electrode, using an impedance circuit that outputs a voltage signal having a waveform corresponding to a current flowing between the detection electrode and the ground portion. Obtaining the voltage signal output from the impedance circuit, and observing a magnitude relationship between the magnitude of the obtained voltage signal and a predetermined threshold value, Under the condition that the discharge electrode is not attached to the electrode attachment portion, the magnitude of the peak value of the voltage signal output from the impedance circuit in a state where the high voltage is applied to the electrode attachment portion is A voltage that is equal to or lower than a threshold and is applied to the discharge electrode with the same high voltage as the high voltage applied to the electrode mounting portion under the condition that the discharge electrode is normally attached to the electrode mounting portion ; and The peak value of the voltage signal output from the impedance circuit is set to be larger than the threshold value in a state where no corona discharge is generated from the discharge electrode when the high voltage is applied. Characteristic (sixth invention).

  According to the sixth invention, since the threshold value is set as described with respect to the first invention, by observing the magnitude relationship between the value of the voltage signal and the threshold value, It can be properly grasped by distinguishing from “dust accumulation state”.

The figure which shows the structure of the ion generator which concerns on embodiment of this invention. The figure which shows arrangement | positioning of a discharge electrode and the electrode for a detection. The figure which shows the structure of a discharge electrode, an impedance circuit, and a detection determination circuit. The figure which shows the change of the waveform of a voltage signal by the presence or absence of omission etc. of a discharge electrode. The figure which shows the structural example of an impedance circuit. The figure which shows the example of arrangement | positioning which handles a some discharge electrode and the electrode for a detection as 1 group.

  An embodiment of the present invention will be described with reference to FIGS. As shown in FIG. 1, the ion generator 1 of this embodiment is configured to generate positive and negative air ions by corona discharge. The discharge electrode 2 is detachably attached to an electrode attachment portion 2a. And a high voltage generating circuit 3 for generating positive and negative high voltages to be applied to the discharge electrode 2 through the electrode mounting portion 2a.

  Further, the ion generating apparatus 1 refers to the state in which the discharge electrode 2 has been detached from the electrode mounting portion 2a due to dropping of the discharge electrode 2 or forgetting to attach the discharge electrode 2 (that is, the “attachment abnormal state”). As a configuration for distinguishing and detecting “a dust accumulation state” and the like, a detection electrode 4 disposed opposite to the discharge electrode 2, and an impedance circuit 6 connected between the detection electrode 4 and the grounding unit 5 And a detection determination circuit 7 to which the voltage signal Vp output from the impedance circuit 6 is input.

  The high voltage generation circuit 3 is a circuit that alternately outputs a pulsed positive high voltage and a negative high voltage from the output terminal 3a at a constant cycle. In the present embodiment, the frequency of the high voltage output from the high voltage generation circuit 3 is a frequency of 260 kHz, for example.

  As such a high voltage generation circuit 3, for example, a circuit proposed by the applicant of the present application in Japanese Patent Application Laid-Open No. 2009-4177 is adopted. However, the high voltage generation circuit 3 may have another known circuit configuration. Further, the high voltage generation circuit 3 may be a circuit that outputs a sinusoidal AC high voltage.

  The discharge electrode 2 is composed of a needle-like conductor so as to have a sharp tip. In the present embodiment, the discharge electrode 2 is screwed to the electrode mounting portion 2a connected to the output terminal 3a of the high voltage generation circuit 3 via the capacitive member 8 made of an insulator and the high voltage cable 9. Removably attached. The capacitive member 8 is a member that functions as a capacitor having a predetermined capacitance value. Therefore, in this embodiment, the discharge electrode 2 is connected to the output terminal 3a of the high voltage generation circuit 3 in the form of capacitive coupling.

  A resistive element may be interposed in series with the capacitive member 8 between the electrode mounting portion 2 a and the output terminal 3 a of the high voltage generation circuit 3. Alternatively, instead of the capacitive member 8, the electrode mounting portion 2 a is connected to the high voltage generation circuit 3 via a resistance element (that is, the electrode mounting portion 2 a is connected to the output terminal 3 a of the high voltage generation circuit 3 by resistance coupling). May be connected in a form). Further, the capacitive member 8 and the electrode mounting portion 2a may be integrated.

  The detection electrode 4 is made of a conductor and is disposed so as to face the discharge electrode 2 in the vicinity. More specifically, in this embodiment, as shown in FIGS. 2A and 2B, the detection electrode 4 is formed in an annular shape, for example. The detection electrode 4 surrounds the periphery of the tip of the discharge electrode 2 (in other words, in a direction orthogonal to the axial center direction of the discharge electrode 2 so as to be spaced from the outer peripheral surface of the discharge electrode 2). ), Which is arranged coaxially with the discharge electrode 2.

  However, the detection electrode 4 has a slight gap from the tip of the discharge electrode 2 in the axial direction of the discharge electrode 2 as indicated by a two-dot chain line in FIG. It may be arranged on the front side. Further, the shape of the detection electrode 4 is not limited to an annular shape, and may be a linear shape or a plate shape. The detection electrode 4 may be covered with an insulator.

  Supplementally, the ion generating apparatus 1 of the present embodiment is used as a static eliminator for neutralizing a static elimination object (not shown). For this reason, in the ion generator 1 of this embodiment, when performing static elimination of the static elimination object, the positive and negative air ions produced | generated by the corona discharge in the vicinity of the discharge electrode 2 are made ahead of this discharge electrode 2. 2, it is moved toward the front side of the discharge electrode 2 by an air supply mechanism (blower unit) such as a blower fan (not shown) as indicated by a broken arrow in FIG. Thus, air supply (air blowing) is performed.

  The detection electrode 4 discharges in the direction orthogonal to the axial center direction of the discharge electrode 2 as described above in order to prevent the transfer of air ions from the discharge electrode 2 side to the static elimination object as much as possible. The electrode 2 is disposed so as to be spaced from the electrode 2.

  In the present embodiment, the detection electrode 4 also functions as a counter electrode that generates corona discharge with the discharge electrode 2. The distance between the detection electrode 4 and the tip of the discharge electrode 2 (or the radius of the detection electrode 4) can appropriately generate corona discharge between the discharge electrode 2 and the detection electrode 4. Is set to

  Here, according to the experiment and examination of the present inventor regarding the arrangement of the detection electrode 4, in order to appropriately detect the “attachment abnormal state”, the detection electrode 4 and the tip of the discharge electrode 2 The distance in the axial center direction of the discharge electrode 2 is a distance within the range of −50 to 50 mm (preferably, a distance within the range of −50 to 0 mm), and the discharge electrode 2 and the discharge Discharge electrode 2 so that the distance between electrode 2 and the electrode 2 in the direction perpendicular to the axial direction of discharge electrode 2 is a distance of 50 mm or less (preferably, a distance in the range of 10 to 30 mm). It is desirable to set the arrangement position of the detection electrode 4 with respect to.

  Note that the distance in the axial direction of the discharge electrode 2 is more specifically the distance from the tip of the discharge electrode 2 to the base end side of the discharge electrode 2 as a negative distance (−50 mm or the like), and the tip of the discharge electrode 2. A distance away from the base end side of the discharge electrode 2 to the side opposite to the base end side is defined as a positive distance (50 mm or the like). For example, the distance in the axial center direction of the discharge electrode 2 between the detection electrode 4 and the tip of the discharge electrode 2 indicated by a solid line in FIG. 2A is a negative distance, and two points are shown in FIG. A distance in the axial direction of the discharge electrode 2 between the detection electrode 4 and the tip of the discharge electrode 2 indicated by a chain line is a positive distance.

  Supplementally, the space between the discharge electrode 2 and the detection electrode 4 is electrically expressed by an equivalent circuit as indicated by reference numeral A in FIG. This equivalent circuit A has a resistance of a discharge current that flows through a corona discharge between the discharge electrode 2 and the detection electrode 4 to the capacitive element Ca corresponding to the capacitance between the discharge electrode 2 and the detection electrode 4. This is a circuit in which corresponding resistance elements Rdis are connected in parallel via a switch SWdis.

  In this case, the switch SWdis is a switch that is turned on when corona discharge is generated and is turned off when no corona discharge is generated. Therefore, the equivalent circuit A is configured by a parallel circuit of the capacitive element Ca and the resistance element Rdis in a state where corona discharge is generated, and is configured by the capacitive element Ca when no corona discharge is generated.

  When the discharge electrode 2 is detached from the electrode mounting portion 2a, the capacitive element Ca corresponds to the electrostatic capacitance between the electrode mounting portion 2a and the detection electrode 4. The capacitance value is generally smaller than the capacitance between the discharge electrode 2 normally attached to the electrode mounting portion 2 a and the detection electrode 4.

  The impedance circuit 6 is a circuit configured by circuit elements having impedance. In the present embodiment, the impedance circuit 6 is a parallel circuit configured by connecting two resistance elements 10a and 10b in series as shown in FIG.

  The impedance circuit 6 generates a voltage generated by the resistance element 10b (the detection electrode 4 and the ground portion 5 as a voltage signal Vp corresponding to the current flowing between the detection electrode 4 and the ground portion 5 via the impedance circuit 6). Is a voltage obtained by dividing the voltage between the resistor elements 10a and 10b).

  The detection determination circuit 7 corresponds to the detection means in the present invention. In the present embodiment, the detection determination circuit 7 is configured to have a function of generating a determination signal HLS indicating the magnitude relationship between the magnitude of the voltage signal Vp output from the impedance circuit 6 and a predetermined threshold value. Yes.

  Here, before specifically explaining the detection determination circuit 7, a voltage signal Vp output from the impedance circuit 6 when one of positive and negative high voltages, for example, a positive high voltage is applied to the electrode mounting portion 2a. The relationship between this waveform and the abnormal mounting state of the discharge electrode 2 will be described with reference to FIG.

  FIG. 4 shows the measured voltage signal Vp (output signal of the impedance circuit 6) when a positive high voltage is applied from the high voltage generation circuit 3 to the electrode mounting portion 2a in the actual ion generation apparatus 1 of the present embodiment. ) Is shown in a graph with reference numerals Vp-on, Vp-off, and Vp-br. In this case, the positive high voltage applied to the electrode mounting portion 2a is a pulsed high voltage having a waveform as shown by the graph of the reference symbol Vn.

  The waveform Vp-on among the waveforms Vp-on, Vp-off, and Vp-br of the voltage signal Vp in FIG. 4 normally causes corona discharge from the discharge electrode 2 normally attached to the electrode mounting portion 2a. It is a waveform actually measured in the generated state. The waveform of the voltage signal Vp-off is a waveform actually measured in a state in which corona discharge from the discharge electrode 2 normally attached to the electrode mounting portion 2a is not intentionally generated. Furthermore, the waveform Vp-br of the voltage signal Vp is a waveform actually measured with the discharge electrode 2 removed from the electrode mounting portion 2a.

  As shown in FIG. 4, the waveforms Vp-on, Vp-off, and Vp-br of the voltage signal Vp basically have a voltage value according to the application of a positive high voltage to the electrode mounting portion 2a. It rises to a certain peak value, and then changes so as to fall from the peak value (approaching zero).

  Further, as shown in FIG. 4, it can be seen that the peak values of the waveforms Vp-on and Vp-off are larger than the peak value of Vp-br.

  This is because a high voltage is applied to the electrode mounting portion 2a in a state where the discharge electrode 2 is detached from the electrode mounting portion 2a, so that the static electricity between them is interposed between the electrode mounting portion 2a and the detection electrode 4. The displacement current that flows according to the electric capacity is applied to the discharge electrode 2 and the detection electrode 4 by applying a high voltage to the electrode mounting portion 2a when the discharge electrode 2 is normally attached to the electrode mounting portion 2a. This is considered to be because the displacement current is smaller than the displacement current that flows according to the capacitance between them.

  Note that the above phenomenon occurs similarly when a negative high voltage is applied to the electrode mounting portion 2a. That is, when a negative high voltage (for example, a negative half-wave sine wave) is applied to the electrode mounting portion 2a, the magnitudes of the peak values of the waveforms Vp-on and Vp-off are the magnitudes of the peak values of Vp-br. It will be bigger than that.

  Further, it was confirmed that such a phenomenon occurs similarly even when the discharge electrode 2 is coming off the electrode mounting portion 2a.

  Based on the above description, details of the detection determination circuit 7 will be described below.

  As shown in FIG. 3, the detection determination circuit 7 generates and outputs a shaped voltage signal Vibp, which is a signal obtained by removing high-frequency noise components and DC components from the voltage signal Vp output from the impedance circuit 6. The magnitude of the shaping voltage signal Vibp output from the waveform shaping circuit 12 during a period in which a positive high voltage of positive and negative high voltages is applied from the high voltage generation circuit 3 to the circuit 12 and the electrode mounting portion 2a; And a detection circuit 13 that generates and outputs a signal indicating a magnitude relationship with the threshold value T1 set in advance as the determination signal HLS.

  The waveform shaping circuit 12 is configured by, for example, a bandpass filter having a buffer on the input side. Then, the waveform shaping circuit 12 converts the low-frequency component (mainly DC component) below the low-frequency cutoff frequency of the bandpass filter and the high-frequency component (mainly noise component) above the high-frequency cutoff frequency to the voltage. By removing from the signal Vp, the shaped voltage signal Vibs is generated and output.

  The detection circuit 13 compares the magnitude of the shaped voltage signal Vibs with a preset threshold value T1 during a period in which a positive high voltage is applied to the electrode mounting portion 2a, and indicates a magnitude relationship. A circuit that generates and outputs a determination signal HLS, and is configured using, for example, a comparison circuit.

  More specifically, during a period in which a positive high voltage is applied to the electrode mounting portion 2a, the shaped voltage signal Vibs has a waveform whose magnitude continuously exceeds a threshold T1 for a predetermined time or more. In the case of a voltage signal, the detection circuit 13 outputs a high level signal as the determination signal HLS. On the other hand, when the magnitude of the shaped voltage signal Vibs is kept below the threshold T1 during a period in which a positive high voltage is applied to the electrode mounting portion 2a, the detection circuit 13 outputs a low level as the determination signal HLS. Output level signal.

  The condition for outputting the high-level signal that the time when the magnitude of the shaped voltage signal Vibs exceeds the threshold T1 continues for a predetermined time or more is the condition for outputting the high level signal because the magnitude of the shaped voltage signal Vibs is temporarily due to noise or the like. This is because a high level signal is not output when the threshold value T1 is exceeded.

  Here, the threshold value T1 is a voltage output from the impedance circuit 6 in a state where a positive high voltage is applied to the electrode mounting portion 2a under the condition that the discharge electrode 2 is not attached to the electrode mounting portion 2a. The peak value of the signal Vp is equal to or less than the threshold T1, and a positive high voltage is applied to the discharge electrode 2 under the condition that the discharge electrode 2 is attached to the electrode mounting portion 2a. The peak value of the voltage signal Vp output from the impedance circuit 6 is larger than the threshold value T1 in a state where no corona discharge is intentionally generated from the discharge electrode 2 when the high voltage is applied. It has been set experimentally.

  In other words, as shown in FIG. 4, the threshold value T1 is the threshold voltage of the shaped voltage signal Vibs when a positive high voltage is applied to the electrode mounting portion 2a with the discharge electrode 2 intentionally removed from the electrode mounting portion 2a. The shaping voltage signal Vibs when the discharge electrode 2 is normally attached to the electrode mounting portion 2a and a positive high voltage is applied to the electrode mounting portion 2a without intentionally generating a corona discharge. It is experimentally set to be a value less than the peak value.

  Since the threshold value T1 is set in this way, when the shaping voltage signal Vibs is equal to or less than the threshold value T1, it corresponds to an “attachment abnormality state”. On the other hand, when the shaping voltage signal Vibs is equal to or less than the threshold value T1, this corresponds to a state in which the discharge electrode 2 is normally attached.

  In the present embodiment, the detection circuit 13 is configured such that the determination signal HLS is always maintained at a low level while a negative high voltage is applied to the electrode mounting portion 2a.

  Instead of generating the determination signal HLS in the detection circuit 13, the determination signal HLS may be generated by digital processing or software processing based on a digital signal obtained by A / D converting the output signal of the waveform shaping circuit 12.

  In the present embodiment, the output of the detection determination circuit 7 (the determination signal HLS output from the detection circuit 13) is used to control the operation of an indicator (not shown) such as a display, a lamp, and a buzzer, and the high voltage generation circuit. 3 is used for operation control. More specifically, when the determination signal HLS is maintained at a low level during a period in which a positive high voltage is applied to the electrode mounting portion 2a, this is a state corresponding to an “attachment abnormal state”. In response to the determination signal HLS, the operator or the like is notified that an “abnormal mounting state” such as the discharge electrode 2 being dropped or forgotten to be mounted. At the same time, the operation of the high voltage generation circuit 3 (high voltage output) is stopped.

  In addition, the ion generator 1 notifies the occurrence of the “mounting abnormality state” and the high voltage generation circuit 3 when the determination signal HLS is maintained at a low level in one cycle of high voltage application to the discharge electrode 2. May be configured to stop the operation, or when the determination signal HLS is maintained at a low level for a plurality of consecutive periods of high voltage application, notification of the occurrence of an “attachment abnormal state” and generation of a high voltage The operation of the circuit 3 may be stopped.

  Next, the whole operation | movement regarding the detection of the production amount of the air ion of the ion generator 1 of this embodiment is demonstrated.

  When neutralizing an object to be neutralized (charged object), the high voltage generation circuit 3 is activated, so that positive and negative high voltages are constant from the output terminal 3a of the high voltage generation circuit 3 to the electrode mounting portion 2a. It is applied alternately with a period. In this case, the air supply mechanism also blows air. However, it is not essential to blow.

  At this time, when the discharge electrode 2 is normally attached to the electrode mounting portion 2a, the electrode mounting portion 2a has a positive or negative high level unless the “deposition state of dust” of the discharge electrode 2 has progressed so much. During the period in which the voltage is applied, the corona from the tip of the discharge electrode 2 is caused by an electric field generated so as to concentrate on the tip of the discharge electrode 2 between the discharge electrode 2 and the detection electrode 4 as the counter electrode. Discharge occurs. And air ion is produced | generated by ionizing air by this corona discharge.

  In this case, positive air ions are generated by corona discharge in a state where a positive high voltage is applied to the discharge electrode 2, and negative air is generated by corona discharge in a state where a negative high voltage is applied to the discharge electrode 2. Air ions are generated.

  The charged charges of the object to be neutralized are neutralized by the positive and negative air ions thus generated, and the object to be neutralized is neutralized.

  During such operation, a current flows through the impedance circuit 6 according to the high voltage, for example, during a period in which a positive or negative high voltage is applied to the discharge electrode 2. When the current flows, a voltage is generated in the resistance element 10b, and this voltage is input to the detection determination circuit 7 as the voltage signal Vp.

  In the detection determination circuit 7, after the noise shaping component and the direct current component are removed from the voltage signal Vp and shaping in the waveform shaping circuit 12, the magnitude relationship between the magnitude of the signal and a predetermined threshold value T <b> 1 is detected by the detection circuit 13. A determination signal HLS is generated.

  Here, when the discharge electrode 2 is normally attached to the electrode mounting portion 2a, not only the “dust accumulation state” has occurred, but also the “dust accumulation state” has occurred. The magnitude of the voltage signal Vp output from the impedance circuit 6 in response to applying a positive high voltage to the discharge electrode 2 is larger than the threshold value T1. In such a case, the detection circuit 13 outputs a high level signal as the determination signal HLS in a state where a positive high voltage is applied to the electrode mounting portion 2a.

  On the other hand, when the “mounting abnormality state” occurs, the magnitude of the voltage signal Vp output from the impedance circuit 6 in response to the application of a positive high voltage to the electrode mounting portion 2a is less than or equal to the threshold T1. Kept. In such a case, the detection circuit 13 outputs a low level signal as the determination signal HLS during a period in which a positive high voltage is applied to the electrode mounting portion 2a.

  Therefore, by monitoring the determination signal HLS of the detection circuit 13 during a period in which a positive high voltage is applied to the electrode mounting portion 2a, the occurrence of the “mounting abnormal state” is changed to the occurrence of the “dust accumulation state”. It can be distinguished and detected.

  In addition, the ion generator 1 monitors the output of the detection circuit 13, and the determination signal HLS is a low level signal for a predetermined period (for example, one period or a period of a plurality of periods in which a positive high voltage is applied to the discharge electrode 2). In this case, the operator is informed that the “mounting abnormality state” has occurred, and the operation of the high voltage generation circuit 3 is stopped, so that positive and negative high voltages are applied to the electrode mounting portion 2a. Blocked.

  As described above, according to the present embodiment, the “abnormal mounting state” can be detected with high reliability in distinction from the “dust accumulation state”. In response to the detection, the operator is informed that the “abnormal attachment state” has occurred, and thus the operator is prevented from overlooking the occurrence of the “abnormal attachment state”. For this reason, a countermeasure for the “abnormal mounting state” is promptly taken. In addition to the notification, the operation in the “abnormal mounting state” can be prevented by blocking the application of positive and negative high voltages to the electrode mounting portion 2a.

(Modification)
In the above-described embodiment, the detection determination circuit 7 detects the occurrence of the “attachment abnormal state” by comparing the magnitude of the voltage signal Vp with the threshold T1 when a positive high voltage is applied to the electrode mounting portion 2a. However, it is configured to detect the occurrence of “an abnormal mounting state” by comparing the magnitude of the voltage signal Vp in a state in which a negative high voltage is applied to the electrode mounting portion 2a with the threshold value T2. May be.

  In this case, the threshold T2 is the waveform of the voltage signal Vp output from the impedance circuit 6 when a negative high voltage is applied to the electrode mounting portion 2a with the discharge electrode 2 removed from the electrode mounting portion 2a. More than the peak value of the shaping voltage signal Vibs in FIG. 5 and a value less than the peak value of the shaping voltage signal Vibs in a state where no corona discharge is intentionally generated from the discharge electrode 2 normally attached to the electrode mounting portion 2a. Should be set to be.

  Alternatively, by comparing the voltage signal Vp of the impedance circuit 6 with the threshold value T1 in both a state where a positive high voltage is applied to the electrode mounting portion 2a and a state where a negative high voltage is applied. The occurrence of “an abnormal mounting state” may be detected.

  In the above-described embodiment, the detection circuit 13 is configured to output the determination signal HLS indicating whether or not the “mounting abnormality state”, but a state in which a positive high voltage is applied to the electrode mounting portion 2a. The voltage signal Vp may be configured to output a signal indicating a difference between the threshold values T1 as a determination signal.

  In the above-described embodiment, the detection electrode 4 is configured to function as a counter electrode that generates corona discharge with the discharge electrode 2. However, the detection electrode 4 and the counter electrode may be provided separately. Good.

  As shown in FIG. 5A, the impedance circuit 6 according to the embodiment is configured by connecting two resistance elements 10a and 10b in series. The impedance circuit 6 outputs the voltage generated by the resistance element 10b as the voltage signal Vp.

  The impedance circuit 6 is not limited to the above form, and may be configured in any way as long as a displacement current and an ionic current flow. Hereinafter, a configuration example of the impedance circuit 6 will be described with reference to FIGS.

  As shown in FIG. 5B, the impedance circuit 6 has two resistance elements 21 and 22 connected in series, the two resistance elements 21 and 22 and a capacitance element 23 connected in parallel, and the resistance element 22 May be configured to output the voltage generated at the voltage signal Vp.

  Further, as shown in FIG. 5C, the impedance circuit 6 may be composed of a single resistance element 21, and a voltage generated in the resistance element 21 may be output as a voltage signal Vp.

  Further, as shown in FIG. 5D, the impedance circuit 6 does not include the resistance element, connects the capacitive element 23 and the capacitive element 24 in series, and outputs the voltage generated in the capacitive element 24 as the voltage signal Vp. It may be configured as follows.

  Further, as shown in FIG. 5E, the impedance circuit 6 is configured so that the resistance element 21 and the capacitance element 23 are connected in parallel and the voltage generated in the resistance element 21 is output as the voltage signal Vp. Also good.

  Further, as shown in FIG. 5 (f), the resistor element 21 and the capacitor element 24 are connected in parallel, the parallel circuit and the capacitor element 23 are connected in series, and the voltage generated in the resistor element 21 is expressed as voltage. The impedance circuit 6 may be configured to output as the signal Vp.

  In addition, as shown in FIG. 5 (g), the resistance element 21 and the capacitance element 23 are connected in parallel, and the parallel circuit and the resistance element 22 are connected in series. The impedance circuit 6 may be configured to be the voltage signal Vp.

  Further, as shown in FIG. 5 (h), a set of the resistor element 21 and the capacitor element 23 connected in parallel and a set of the resistor element 22 and the capacitor element 24 connected in parallel are connected in series. The impedance circuit 6 may be configured to output the voltage generated in the resistance element 22 as the voltage signal Vp.

  In each of the above embodiments, the ion generation apparatus 1 in the case where the discharge electrode 2 is single has been described as an example. However, the ion generation apparatus to which the present invention is applied may include a plurality of discharge electrodes 2. .

  In that case, each discharge electrode 2 may be provided with a set of a detection electrode 4, an impedance circuit 6, and a detection determination circuit 7. However, for example, N ( N: an integer of 2 or more), and the single impedance circuit 6 and the detection determination circuit 7 may be shared for the N discharge electrodes 2 of each group.

  For example, as shown in FIG. 6, detection electrodes 4 arranged to face each of N (five in the illustrated example) discharge electrodes 2 belonging to one group are arranged in parallel with a single impedance circuit 6. And the output (voltage signal Vp) of the impedance circuit 6 may be input to the detection determination circuit 7 similar to each of the above embodiments. In this case, the same high voltage is simultaneously applied to the N discharge electrodes 2 from the high voltage generation circuit 3.

  Even in this case, as will be described later, the voltage signal Vp output from the impedance circuit 6 changes in accordance with the dropout of the N discharge electrodes 2 or forgetting to attach the N discharge electrodes 2. It becomes. Therefore, it is possible to detect an abnormal state such as dropping of the discharge electrode 2 or forgetting to attach the discharge electrode 2 based on the comparison between the voltage signal Vp and the threshold value T1.

  In the example shown in FIG. 6, each of the N discharge electrodes 2 is provided with a detection electrode 4. However, these detection electrodes 4 are integrally configured to form N discharge electrodes. 2 may be provided with a common detection electrode 4. In this case, the common detection electrode 4 is disposed, for example, on a plate-like conductor member having a plurality of through holes facing each discharge electrode 2 or on the side of the N discharge electrodes 2. It can comprise by the rod-shaped conductor member which was made.

  Table 1 shows the number of dropped discharge electrodes (Nd) and impedance when the number N of discharge electrodes 2 connected to a single impedance circuit 6 and detection determination circuit 7 is changed from 1 to 5. 6 is a table showing a relationship with a value of a voltage signal Vp output from a circuit 6.

  As can be seen from Table 1, regardless of the number N of discharge electrodes 2, the value of the voltage signal Vp decreases as the number of dropped electrodes (Nd) increases.

  From this, it can be seen that even when there are a plurality of discharge electrodes (N is 2 or more), it is possible to monitor whether or not the discharge electrodes are dropped or forgotten to be attached.

DESCRIPTION OF SYMBOLS 1 ... Ion generator, 2 ... Discharge electrode, 4 ... Detection electrode, 5 ... Grounding part, 6 ... Impedance circuit, 7 ... Detection determination circuit, Vp ... Voltage signal, HLS ... Determination signal.

Claims (6)

Ions that generate corona discharge from the discharge electrode by alternately applying positive and negative high voltages to the discharge electrode attached to the electrode attachment portion via the electrode attachment portion, and generate air ions by the corona discharge. In the generator,
A detection electrode disposed opposite the discharge electrode;
An impedance circuit that is electrically connected between the detection electrode and the ground portion and outputs a voltage signal having a waveform corresponding to a current flowing between the detection electrode and the ground portion;
Detecting means to which the voltage signal output from the impedance circuit is input,
The detection means generates a determination signal indicating a magnitude relationship between the magnitude of the voltage signal output from the impedance circuit and a predetermined threshold in response to applying a positive or negative high voltage to the discharge electrode. Is configured as
The threshold value is a peak value of the voltage signal output from the impedance circuit in a state where the high voltage is applied to the electrode mounting portion under the condition that the discharge electrode is not mounted on the electrode mounting portion. Under the condition that the size is equal to or less than the threshold value and the discharge electrode is normally attached to the electrode mounting portion, the same high voltage as that applied to the electrode mounting portion is applied to the discharge electrode . The peak value of the voltage signal output from the impedance circuit is set to be larger than the threshold value in a state where no corona discharge is generated from the discharge electrode when the high voltage is applied. An ion generator characterized by being made. The ion generator according to claim 1,
A plurality of the discharge electrodes, and one or more detection electrodes facing N (N: an integer of 2 or more) discharge electrodes of at least one group of the plurality of discharge electrodes,
One or more said detection electrodes facing the said N discharge electrodes are connected to the said single impedance circuit, The ion generator characterized by the above-mentioned. In the ion generator according to claim 1 or 2,
When the determination signal is a signal indicating that the magnitude of the voltage signal is equal to or less than the threshold value, an alarm indicating that a discharge electrode mounting abnormal state has occurred is output. A featured ion generator. In the ion generator according to claim 3,
When the determination signal is a signal indicating that the magnitude of the voltage signal is equal to or less than the threshold value, it is further configured to block application of a high voltage to the electrode mounting portion. Ion generator. In the ion generator according to any one of claims 1 to 4,
The ion generating apparatus, wherein the detection electrode is arranged so as to function as a counter electrode that generates corona discharge between the discharge electrode and the counter electrode. Ions that generate corona discharge from the discharge electrode by alternately applying positive and negative high voltages to the discharge electrode attached to the electrode attachment portion via the electrode attachment portion, and generate air ions by the corona discharge. In the generator, a method for monitoring the mounting state of the discharge electrode,
An impedance circuit that is electrically connected between a detection electrode disposed opposite to the discharge electrode and a ground portion and outputs a voltage signal having a waveform corresponding to a current flowing between the detection electrode and the ground portion. Use
Obtaining the voltage signal output from the impedance circuit in response to applying a positive or negative high voltage to the discharge electrode;
Observing the magnitude relationship between the magnitude of the acquired voltage signal and a predetermined threshold,
The threshold value is a peak value of the voltage signal output from the impedance circuit in a state where the high voltage is applied to the electrode mounting portion under the condition that the discharge electrode is not mounted on the electrode mounting portion. Under the condition that the size is equal to or less than the threshold value and the discharge electrode is normally attached to the electrode mounting portion, the same high voltage as that applied to the electrode mounting portion is applied to the discharge electrode . The peak value of the voltage signal output from the impedance circuit is set to be larger than the threshold value in a state where no corona discharge is generated from the discharge electrode when the high voltage is applied. Discharge electrode attachment state monitoring method characterized by being carried out.

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