JPH05269408A - Method for detecting spark in high voltage electrode of electrostatic coating machine and apparatus for the same - Google Patents
Method for detecting spark in high voltage electrode of electrostatic coating machine and apparatus for the sameInfo
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- JPH05269408A JPH05269408A JP10017792A JP10017792A JPH05269408A JP H05269408 A JPH05269408 A JP H05269408A JP 10017792 A JP10017792 A JP 10017792A JP 10017792 A JP10017792 A JP 10017792A JP H05269408 A JPH05269408 A JP H05269408A
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- current curve
- high voltage
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Abstract
Description
【０００１】[0001]
【産業上の利用分野】本発明は、静電塗装装置において
接地された被塗装物品が高電圧電極に接近した際に生じ
る火花放電を抑制するため、高電圧電源装置と接地との
間に介在させた高電圧スイッチをスイッチングさせる火
花放電発生予知信号を得るための方法及びその装置に係
り、特に火花放電に至らないコロナ放電に反応すること
なく火花放電のみを検出可能とした火花放電検知方法及
びその装置に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention interposes between a high-voltage power supply device and a ground in order to suppress spark discharge generated when an article to be grounded in an electrostatic coating device approaches a high-voltage electrode. The present invention relates to a method and an apparatus for obtaining a spark discharge occurrence prediction signal for switching a high-voltage switch, and in particular, a spark discharge detection method capable of detecting only spark discharge without reacting to corona discharge that does not result in spark discharge, and Regarding the device.
【０００２】[0002]
【従来の技術】静電塗装装置は、例えば図７に示すよう
に、可変直流高電圧発生器Ｅ等から構成される直流高電
圧電源装置１と、腕状に形成された高電圧電極２と、高
電圧電極側と低電圧端子（接地）間に接続された高電圧
スイッチ３と、高電圧スイッチ３の開閉を制御する制御
回路４とを具備して構成されている。図中、抵抗Ｒはそ
れぞれ電流制限用の抵抗である。そして、前記高電圧電
極２に直流高電圧電源装置１による高電圧を印加すると
ともに、高電圧電極２を高速度で回転させて塗料を流出
させると、塗料が遠心力によって高電圧電極２周囲から
荷電量をもった塗料粒子として噴霧し、この塗料粒子が
接地された被塗装物５にクーロン力により収着されるこ
とにより塗装を行なう。2. Description of the Related Art As shown in FIG. 7, for example, an electrostatic coating apparatus includes a DC high voltage power supply unit 1 including a variable DC high voltage generator E and the like, and an arm-shaped high voltage electrode 2. A high voltage switch 3 connected between the high voltage electrode side and the low voltage terminal (ground), and a control circuit 4 for controlling the opening and closing of the high voltage switch 3 are configured. In the figure, resistors R are resistors for limiting current, respectively. Then, when a high voltage is applied to the high voltage electrode 2 by the DC high voltage power supply device 1 and the high voltage electrode 2 is rotated at a high speed to allow the paint to flow out, the paint is centrifugally removed from the periphery of the high voltage electrode 2. Coating is performed by spraying as paint particles having a charge amount, and the paint particles are adsorbed on the grounded object 5 by Coulomb force.
【０００３】上記静電塗装装置は高電圧を使用するので
火花放電が生じる可能性があり、直流高電圧発生器Ｅの
出力負荷電流を電流検出回路６により検出し、該検出信
号に基づいて火花放電発生予知回路７において火花発生
を予知した警報信号が生じると、この信号により駆動回
路８から駆動信号が発生し、この駆動信号により制御回
路５からの信号を受けて高電圧スイッチ３を閉じ、直流
高電圧電源装置１の出力端子Ｏと静電塗装用ガンの入力
端子Ｉ間を接続する高圧ケーブル８が有する対地容量Ｃ
1 に蓄積された電荷、高電圧電極２と被塗装物５及び高
電圧電極２と対地間に形成される容量Ｃ2 に蓄積された
電荷を放電させて火花放電の発生を防止していた。Since the electrostatic coating device uses a high voltage, there is a possibility that spark discharge may occur. The output load current of the DC high voltage generator E is detected by the current detection circuit 6, and the spark is generated based on the detection signal. When an alarm signal predicting the occurrence of sparks is generated in the discharge occurrence prediction circuit 7, a drive signal is generated from the drive circuit 8 by this signal, and the high voltage switch 3 is closed by receiving a signal from the control circuit 5 by this drive signal. The ground capacity C of the high voltage cable 8 connecting the output terminal O of the DC high voltage power supply device 1 and the input terminal I of the electrostatic coating gun
The charge accumulated in 1 and the charge accumulated in the capacitor C2 formed between the high voltage electrode 2 and the object to be coated 5 and between the high voltage electrode 2 and the ground are discharged to prevent the occurrence of spark discharge.
【０００４】従来、火花放電発生予知回路７による火花
放電の検知方法としては、電流検出回路６により検出し
た出力負荷電流の時間に対する変化量（微分値）を求
め、この値が予め設定された設定値より大きい場合に火
花放電発生と検知して火花放電発生予知信号を発生させ
る方法が採られていた（例えば、特開昭５８ー６１８５
２号公報、特公昭５５ー３５９８９号公報参照）。Conventionally, as a method of detecting spark discharge by the spark discharge occurrence prediction circuit 7, a change amount (differential value) of the output load current detected by the current detection circuit 6 with respect to time is obtained, and this value is set in advance. When the value is larger than the value, a method of detecting a spark discharge occurrence and generating a spark discharge occurrence prediction signal has been adopted (for example, JP-A-58-6185).
No. 2, Japanese Patent Publication No. 55-35989).
【０００５】[0005]
【発明が解決しようとする課題】しかしながら上記検知
方法によると、火花放電に至らないコロナ放電によるコ
ロナノイズの微分値も大きな値となり、これについても
火花放電発生と検知してしまうので高電圧スイッチ３を
閉じる回数が多く、その度に塗装工程が遮断されるので
塗装効率が悪くなるという問題点があった。However, according to the above detection method, the differential value of the corona noise due to the corona discharge that does not lead to the spark discharge also becomes a large value, and this is also detected as the spark discharge. Therefore, the high voltage switch 3 There is a problem that the coating efficiency is deteriorated because the coating process is interrupted each time the is closed many times.
【０００６】一方、出力負荷電流の絶対値が予め設定し
た設定値を越えた場合に火花放電発生と検知する検知方
法もあるが、この場合、静電塗装装置の電極の汚れによ
る電流漏洩、被塗装物の移動による負荷電流値の変動等
により、出力負荷電流を１０〜１００μＡとして静電塗
装装置を運転している場合、前記設定値を２００μＡ程
度に設定する必要があるため、火花放電発生時の検出の
遅れが生じ、火花放電の防止ができなくなるという問題
点がある。On the other hand, there is a detection method for detecting the occurrence of spark discharge when the absolute value of the output load current exceeds a preset value. When an electrostatic coating device is operated with an output load current of 10 to 100 μA due to fluctuations in the load current value due to movement of the coated object, it is necessary to set the set value to about 200 μA. However, there is a problem that the spark discharge cannot be prevented and the detection of is delayed.
【０００７】本発明は上記実情に鑑みてなされたもの
で、コロナ放電を検知することなく、火花放電のみを確
実に検知可能とした静電塗装装置の高電圧電極に於ける
火花放電検知方法及びその装置を提供することを目的と
している。The present invention has been made in view of the above circumstances, and a method for detecting spark discharge in a high-voltage electrode of an electrostatic coating device capable of reliably detecting only spark discharge without detecting corona discharge, and It is intended to provide the device.
【０００８】[0008]
【問題点を解決するための手段】上記目的を達成するた
め請求項１に記載された静電塗装装置の高電圧電極に於
ける火花放電検知方法は、次のように検知することを特
徴としている。先ず、静電塗装装置の高電圧電極を流れ
る電流を常時検知することにより変動電流曲線を設定す
る。次に、この変動電流曲線中に含まれるコロナ放電の
立上がり値より大きい値を前記変動電流曲線に加算する
とともに前記コロナ放電の持続時間より長く且つ前記高
電圧電極と被塗装物との接近による電流変化時間より短
い時間遅らせた比較電流曲線を設定する。そして、該比
較電流曲線と前記変動電流曲線とが交差する時点を火花
放電発生と検知する。In order to achieve the above object, a method for detecting spark discharge in a high voltage electrode of an electrostatic coating device according to claim 1 is characterized in that it is detected as follows. There is. First, the fluctuating current curve is set by constantly detecting the current flowing through the high voltage electrode of the electrostatic coating device. Next, a value larger than the rising value of the corona discharge included in the fluctuating current curve is added to the fluctuating current curve, and the current is longer than the duration of the corona discharge and due to the approach of the high voltage electrode and the object to be coated. A comparative current curve delayed by a time shorter than the change time is set. Then, the time point when the comparative current curve and the variable current curve intersect is detected as the occurrence of spark discharge.
【０００９】請求項２に記載された静電塗装装置の高電
圧電極に於ける火花放電検知装置は、次の構成を具備す
ることを特徴としている。静電塗装装置の高電圧電極を
流れる電流変動を検出する検出器を設ける。この検出器
から出力される信号を、前記検出器で検出されるコロナ
放電の持続時間より長く且つ前記高電圧電極と被塗装物
との接近による電流変化時間より短い時間遅延させる遅
延回路を設ける。前記コロナ放電の立上がり値より大き
い値を前記遅延回路の出力に加算する加算器を設ける。
この加算器の出力信号と前記検出器の出力信号とを比較
する比較回路を設ける。A spark discharge detecting device for a high voltage electrode of an electrostatic coating device according to a second aspect is characterized by having the following configuration. A detector is provided to detect fluctuations in the current flowing through the high voltage electrodes of the electrostatic coating device. A delay circuit is provided to delay the signal output from this detector by a time longer than the duration of the corona discharge detected by the detector and shorter than the current change time due to the approach of the high voltage electrode and the object to be coated. An adder for adding a value larger than the rising value of the corona discharge to the output of the delay circuit is provided.
A comparator circuit is provided for comparing the output signal of the adder with the output signal of the detector.
【００１０】請求項３に記載された静電塗装装置の高電
圧電極に於ける火花放電検知方法は、次のように検知す
ることを特徴としている。先ず、静電塗装装置の高電圧
電極を流れる電流を常時検知することにより変動電流曲
線を設定する。次に、この変動電流曲線中に含まれるコ
ロナ放電の立上がり値より大きい値を前記変動電流曲線
に加算するとともに、前記変動電流曲線の微分値が予め
設定した設定値を越えた場合に前記変動電流曲線の値を
前記コロナ放電の持続時間より長い時間保持する比較電
流曲線を設定する。そして、該比較電流曲線と前記変動
電流曲線とが交差する時点を火花放電発生と検知する。The spark discharge detection method for the high voltage electrode of the electrostatic coating device according to the third aspect is characterized by the following detection. First, the fluctuating current curve is set by constantly detecting the current flowing through the high voltage electrode of the electrostatic coating device. Next, a value larger than the rising value of the corona discharge included in the fluctuating current curve is added to the fluctuating current curve, and the fluctuating current is exceeded when the differential value of the fluctuating current curve exceeds a preset value. A comparative current curve is set which holds the value of the curve for longer than the duration of the corona discharge. Then, the time point when the comparative current curve and the variable current curve intersect is detected as the occurrence of spark discharge.
【００１１】請求項４に記載された静電塗装装置の高電
圧電極に於ける火花放電検知装置は、次の構成を具備す
ることを特徴としている。静電塗装装置の高電圧電極を
流れる電流変動を検出する検出器を設ける。この検出器
から出力される信号を微分する微分回路を設ける。この
微分回路の出力を予め設定した値と比較する微分値比較
回路を設ける。前記検出器で検出されるコロナ放電の立
上がり値より大きい値を前記検出器の出力に加算する加
算器を設ける。前記微分値比較回路の出力信号により、
前記検出器で検出されるコロナ放電の持続時間より長い
時間だけ前記加算器の出力を保持する保持回路を設け
る。この保持回路の出力信号と前記検出器の出力信号と
を比較する比較回路を設ける。A spark discharge detecting device for a high voltage electrode of an electrostatic coating device according to a fourth aspect is characterized by having the following configuration. A detector is provided to detect fluctuations in the current flowing through the high voltage electrodes of the electrostatic coating device. A differentiating circuit for differentiating the signal output from this detector is provided. A differential value comparison circuit is provided which compares the output of the differentiating circuit with a preset value. An adder is provided for adding to the output of the detector a value greater than the rising value of corona discharge detected by the detector. By the output signal of the differential value comparison circuit,
A holding circuit for holding the output of the adder for a time longer than the duration of the corona discharge detected by the detector is provided. A comparison circuit for comparing the output signal of the holding circuit and the output signal of the detector is provided.
【００１２】[0012]
【作用】本発明によれば、負荷電流を常時検知すること
により求められる変動電流曲線に対し、この変動電流に
含まれるコロナ放電によるノイズと交差しないような比
較電流曲線を設定し、該比較電流曲線と前記変動電流曲
線とが交差する時点を火花放電発生と検知するので、コ
ロナ放電を火花放電として検知することを防ぐことがで
きる。According to the present invention, for the fluctuating current curve obtained by constantly detecting the load current, a comparative current curve which does not intersect with noise due to corona discharge included in the fluctuating current is set, and the comparative current curve is set. It is possible to prevent the corona discharge from being detected as the spark discharge because the spark discharge is detected at the time when the curve and the variable current curve intersect.
【００１３】[0013]
【実施例】以下、本発明に係る火花放電検知装置の第１
の実施例について図１ないし図３を参照しながら説明す
る。図１は火花放電検知装置のブロック図、図２（ａ）
〜（ｆ）は火花放電検知装置を構成する各回路の出力波
形図、図３は火花放電検知装置全体の回路構成図であ
る。EXAMPLE A first example of a spark discharge detection device according to the present invention will be described below.
The embodiment will be described with reference to FIGS. 1 to 3. FIG. 1 is a block diagram of a spark discharge detection device, FIG. 2 (a)
(F) is an output waveform diagram of each circuit constituting the spark discharge detection device, and FIG. 3 is a circuit configuration diagram of the entire spark discharge detection device.
【００１４】この火花放電検知装置は、静電塗装装置の
高電圧電極を流れる電流の変動を検出する検出回路１１
と、前記変動電流のノイズを除去するフィルター回路１
２と、フィルター回路１２の出力を増幅する増幅回路１
３と、増幅回路１３の出力を遅延させる遅延回路１４
と、設定回路１５で設定された値を前記遅延回路１４の
出力に加算する加算回路１６と、加算回路１６の出力と
増幅回路１３の出力を比較する比較回路１７とから構成
されている。すなわち、静電塗装装置の直流高電圧発生
器Ｅから発生し、高電圧電極２と接地された被塗装物５
との間を流れる負荷電流ｉは、検出回路１１を構成する
抵抗１０１の両端に生じる電圧変化により検出される。
検出回路１１から出力される電流信号は、高電圧電極２
が被塗装物５に対して接近したり離れたりするので、図
２（ａ）に示すように時間とともに変動する波形とな
る。This spark discharge detection device is a detection circuit 11 for detecting the fluctuation of the current flowing through the high voltage electrode of the electrostatic coating device.
And a filter circuit 1 for removing the noise of the fluctuating current
2 and an amplifier circuit 1 for amplifying the output of the filter circuit 12
3 and a delay circuit 14 for delaying the output of the amplifier circuit 13
And an adder circuit 16 for adding the value set by the setting circuit 15 to the output of the delay circuit 14, and a comparator circuit 17 for comparing the output of the adder circuit 16 and the output of the amplifier circuit 13. That is, the object to be coated 5 generated from the DC high voltage generator E of the electrostatic coating device and grounded to the high voltage electrode 2
The load current i flowing between and is detected by a voltage change generated across the resistor 101 forming the detection circuit 11.
The current signal output from the detection circuit 11 is the high voltage electrode 2
Moves toward and away from the object 5 to be coated, so that the waveform changes with time as shown in FIG.
【００１５】フィルター回路１２は高周波信号を除去す
るローパスフィルターで形成され、検出回路１１から出
力される電流信号に含まれる高周波ノイズや高電圧発生
器Ｅを構成するトランスから発生する振動波等のノイズ
を除去する。従って、フィルター回路１２からの出力電
流は、図２（ｂ）に示すように、変動電流にコロナ放電
や火花放電の放電ノイズが含まれた波形となる。The filter circuit 12 is formed of a low-pass filter for removing high frequency signals, and includes high frequency noise included in the current signal output from the detection circuit 11 and noise such as vibration waves generated from the transformer forming the high voltage generator E. To remove. Therefore, as shown in FIG. 2B, the output current from the filter circuit 12 has a waveform in which the fluctuating current includes discharge noise of corona discharge or spark discharge.
【００１６】増幅回路１３は、フィルター回路１２から
出力される電流信号を増幅することにより、変動電流に
含まれる放電ノイズの絶対的な変化量を大きくししてい
る（図２（ｃ））。遅延回路１４は、増幅回路１３の電
流信号を一定時間ｔ１遅延させる積分器から構成されて
いる（図２（ｄ））。この一定時間ｔ１は、変動電流に
含まれるコロナ放電の持続時間より十分長く、被塗装物
と高電圧電極とが相対的に移動することにより両者の距
離変化に応じて負荷電流ｉが変化する時間より十分短い
時間、具体的には数１０μ秒〜数ｍ秒である。The amplification circuit 13 amplifies the current signal output from the filter circuit 12 to increase the absolute change amount of the discharge noise included in the fluctuating current (FIG. 2 (c)). The delay circuit 14 is composed of an integrator that delays the current signal of the amplifier circuit 13 for a fixed time t1 (FIG. 2 (d)). This fixed time t1 is sufficiently longer than the duration of the corona discharge included in the fluctuating current, and the load current i changes according to the distance change between the object to be coated and the high-voltage electrode due to relative movement. It is a sufficiently shorter time, specifically several tens of microseconds to several milliseconds.
【００１７】加算回路１６は、予め設定回路１５により
設定された設定値ｄを、前記遅延回路１４の電流信号に
加算する。設定回路１５により設定される設定値ｄは、
変動電流に含まれるコロナ放電の立上がり値より大きい
値とする。従って、加算回路１６から出力される電流信
号は図２（ｅ）のような比較電流曲線となり、変動電流
に含まれるコロナ放電によるノイズのピーク値が、時間
ｔ1 遅延させて設定値ｄを加算した比較電流曲線と交差
しないようにしている。The adder circuit 16 adds the set value d preset by the setting circuit 15 to the current signal of the delay circuit 14. The set value d set by the setting circuit 15 is
The value should be larger than the rising value of corona discharge included in the fluctuating current. Therefore, the current signal output from the adder circuit 16 becomes a comparison current curve as shown in FIG. 2E, and the peak value of noise due to corona discharge included in the fluctuation current is delayed by the time t1 and the set value d is added. The comparison current curve is not crossed.
【００１８】加算回路１６からの出力信号と前記増幅回
路１３からの出力信号とは比較回路１７に入力され、図
２（ｆ）に示すように、図２（ｃ）と図２（ｅ）の電流
信号同士が常時比較され、増幅回路１６からの出力信号
の方が大きくなるとき（図２（ｃ）の変動電流曲線と図
２（ｅ）の比較電流曲線との交差する時点）、火花放電
発生と検知して警報信号を比較回路１７から出力する。
この警報信号により、例えば図７に示した高電圧電極側
と低電圧端子（接地）間に接続された高電圧スイッチ３
を制御回路４の信号によりオンさせ、火花放電の発生を
未然に防止する。The output signal from the adder circuit 16 and the output signal from the amplifier circuit 13 are input to the comparison circuit 17, and as shown in FIG. 2 (f), the output signals of FIG. 2 (c) and FIG. 2 (e) are obtained. When the current signals are constantly compared with each other and the output signal from the amplifier circuit 16 becomes larger (at the time when the fluctuating current curve of FIG. 2C and the comparative current curve of FIG. 2E cross each other), spark discharge Upon detection of occurrence, an alarm signal is output from the comparison circuit 17.
With this alarm signal, for example, the high voltage switch 3 connected between the high voltage electrode side and the low voltage terminal (ground) shown in FIG.
Is turned on by a signal from the control circuit 4 to prevent spark discharge from occurring.
【００１９】図３は火花放電検知装置の具体的な回路を
示すもので、図１と同一構成をとる部分は同一符号を付
している。検出回路１１は、抵抗１０１の両端に生じる
電圧変化を検出することにより、高電圧電極２と接地さ
れた被塗装物５との間を流れる負荷電流（変動電流）ｉ
を検出する。フィルター回路１２の入力側にはツェナダ
イオード１０２が接続され、フィルター回路１２の入力
側に供給される信号が予め設定された電圧レベルを越え
ることを防止している。フィルター回路１２は、演算増
幅器１０３と、この演算増幅器１０３の入力及び出力に
接続された抵抗１０４，１０５及びコンデンサ１０６，
１０７により所望の伝達関数を有したローパスフィルタ
ーで構成されている。従って、演算増幅器１０３の出力
端子に現れる信号は、高周波成分が除去され、被塗装物
５が静電塗装装置の高電圧電極２に接近するにしたがっ
てその大きさが増し、高電圧電極２から離れるにしたが
ってその大きさが減少する電圧信号となる。FIG. 3 shows a specific circuit of the spark discharge detection device, and parts having the same configuration as in FIG. 1 are designated by the same reference numerals. The detection circuit 11 detects a voltage change generated across the resistor 101 to detect a load current (fluctuation current) i flowing between the high-voltage electrode 2 and the grounded object 5.
To detect. A Zener diode 102 is connected to the input side of the filter circuit 12 to prevent the signal supplied to the input side of the filter circuit 12 from exceeding a preset voltage level. The filter circuit 12 includes an operational amplifier 103, resistors 104 and 105 and capacitors 106, which are connected to the input and output of the operational amplifier 103.
A low pass filter 107 having a desired transfer function is formed. Therefore, the signal appearing at the output terminal of the operational amplifier 103 has its high frequency component removed, its size increases as the workpiece 5 approaches the high voltage electrode 2 of the electrostatic coating apparatus, and the signal is separated from the high voltage electrode 2. Becomes a voltage signal whose magnitude decreases accordingly.
【００２０】増幅回路１３は、演算増幅器１０８と、演
算増幅器１０８の入力側に接続された抵抗１０９と、一
端側を前記抵抗１０９と演算増幅器１０８の接続点に接
続し他端側を接地した抵抗１１０と、演算増幅器１０８
と並列に接続された抵抗１１２とから構成され、抵抗１
０９と抵抗１１０とで増幅比を定め前記フィルター回路
１２の出力信号を増幅する。The amplifier circuit 13 includes an operational amplifier 108, a resistor 109 connected to the input side of the operational amplifier 108, a resistor having one end connected to the connection point of the resistor 109 and the operational amplifier 108 and the other end grounded. 110 and operational amplifier 108
And a resistor 112 connected in parallel with the resistor 1
09 and the resistor 110 determine the amplification ratio and amplify the output signal of the filter circuit 12.
【００２１】遅延回路１４は、前記増幅回路１３の出力
側に接続された抵抗１１３と、該抵抗１１３に直列に接
続し他端側を接地させたコンデンサ１１４と、前記抵抗
１１３とコンデンサ１１４との接続点に入力側を接続し
た演算増幅器１１５と、該演算増幅器１１５と並列に接
続された抵抗１１６とから成る積分器で構成され、増幅
回路１３の出力信号を時間ｔ1 遅延させる。時間ｔ1
は、前記したように、変動電流に含まれるコロナ放電の
持続時間より十分長く、被塗装物と高電圧電極とが相対
的に移動することにより両者の距離変化に応じて負荷電
流ｉが変化する時間より十分短い。The delay circuit 14 includes a resistor 113 connected to the output side of the amplifier circuit 13, a capacitor 114 connected in series to the resistor 113 and having the other end side grounded, the resistor 113 and the capacitor 114. The integrator is composed of an operational amplifier 115 having an input side connected to the connection point and a resistor 116 connected in parallel with the operational amplifier 115, and delays the output signal of the amplifier circuit 13 by time t1. Time t1
Is sufficiently longer than the duration of corona discharge included in the variable current, and the load current i changes according to the distance change between the object to be coated and the high-voltage electrode due to relative movement. Shorter than time.
【００２２】設定回路１５は、定電圧源―Ｖと、抵抗１
１７を介して前記定電圧源―Ｖに直列に接続された可変
抵抗１１９と、この可変抵抗１１９に並列に接続された
ツェナーダイオード１１８と、前記可変抵抗の可変端子
に入力側を接続した演算増幅器１２０と、該演算増幅器
１２０と並列に接続した抵抗１２１とから構成され、前
記負荷電流（変動電流）ｉに含まれるコロナ放電の立上
がり値より大きい値が出力するようにしている。The setting circuit 15 includes a constant voltage source -V and a resistor 1
A variable resistor 119 connected in series to the constant voltage source -V via 17, a Zener diode 118 connected in parallel to the variable resistor 119, and an operational amplifier having an input side connected to a variable terminal of the variable resistor. 120 and a resistor 121 connected in parallel with the operational amplifier 120 so that a value larger than the rising value of the corona discharge included in the load current (fluctuation current) i is output.
【００２３】加算回路１６は、前記遅延回路１４の出力
側に接続された抵抗１２２と、前記設定回路１５の出力
側に接続された抵抗１２３と、一端側を前記抵抗１２２
及び抵抗１２３に接続し他端側を接地した抵抗１２４
と、各抵抗１２２，１２３，１２４の接続点に入力側を
接続した演算増幅器１２５と、該演算増幅器１２５と並
列に接続した抵抗１２６とから構成され、前記遅延回路
１４の出力電圧に設定回路１５の出力電圧を上乗せして
（レベルシフトさせて）出力信号としている。The adder circuit 16 has a resistor 122 connected to the output side of the delay circuit 14, a resistor 123 connected to the output side of the setting circuit 15, and one end of the resistor 122.
And a resistor 124 connected to the resistor 123 and having the other end grounded
And an operational amplifier 125 having an input side connected to a connection point of the resistors 122, 123, and 124, and a resistor 126 connected in parallel with the operational amplifier 125. The setting circuit 15 sets the output voltage of the delay circuit 14 to the output voltage. The output voltage is added (level-shifted) to obtain the output signal.
【００２４】比較回路１７は、前記加算回路１６の出力
側に接続された抵抗１２７と、前記増幅回路１３の出力
側に接続された抵抗１２８と、抵抗１２７及び抵抗１２
８の他端側をそれぞれ入力側とする演算増幅器１２９と
から構成され、加算回路１６からの出力信号と前記増幅
回路１３からの出力信号とを比較し、増幅回路１３から
の出力信号の方が大きいとき、火花放電発生と検知して
警報信号を出力する。また、増幅回路１３からの出力信
号は、もう一方の比較回路１９に入力されている。すな
わち比較回路１９は、抵抗１２８と並列接続された抵抗
１３０と、抵抗１３１と、抵抗１３０及び抵抗１３１の
一端側をそれぞれ入力側とする演算増幅器１３２とから
構成され、この比較回路１９の他方の入力側（抵抗１３
１側）は、前記設定回路１５と同様に構成された（定電
圧源の極性のみ異なる）リミッター設定回路１８が接続
され、増幅回路１３からの出力信号が一定の値を越えた
場合に警報信号を出力するようになっている。すなわ
ち、緩やかに電流値（電流絶対値）が上昇する場合等に
は、この比較回路１９による警報信号により火花放電の
発生を未然に防止することができる。The comparison circuit 17 has a resistor 127 connected to the output side of the adder circuit 16, a resistor 128 connected to the output side of the amplifier circuit 13, a resistor 127 and a resistor 12.
8 is composed of an operational amplifier 129 having the other end side as an input side, respectively, and compares the output signal from the adder circuit 16 with the output signal from the amplifier circuit 13, and the output signal from the amplifier circuit 13 is When it is larger, a spark signal is detected and an alarm signal is output. The output signal from the amplifier circuit 13 is input to the other comparison circuit 19. That is, the comparison circuit 19 is composed of a resistance 130 connected in parallel with the resistance 128, a resistance 131, and an operational amplifier 132 having one ends of the resistance 130 and the resistance 131 as input sides, respectively. Input side (resistor 13
(1 side) is connected to a limiter setting circuit 18 having the same configuration as the setting circuit 15 (only the polarity of the constant voltage source is different), and an alarm signal is output when the output signal from the amplifier circuit 13 exceeds a certain value. Is to be output. That is, when the current value (current absolute value) gradually rises, the alarm signal from the comparison circuit 19 can prevent spark discharge from occurring.
【００２５】本実施例によれば、変動電流曲線中に含ま
れるコロナ放電の立上がり値より大きい値を前記変動電
流曲線に加算し、コロナ放電の持続時間より十分長く且
つ前記高電圧電極と被塗装物との接近（静電塗装装置の
運転）による電流変化時間より十分短い時間ｔ1遅らせ
た比較電流曲線を設定したので、コロナ放電によるノイ
ズ及び前記静電塗装装置の運転による緩やかな電流値の
増加については、比較電流曲線と変動電流曲線とが交差
することがない。従って、比較電流曲線と前記変動電流
曲線とが交差する時点を検知することにより、火花放電
発生のみを確実に検知することができ、静電塗装装置を
効率良く運転することができる。According to this embodiment, a value larger than the rising value of corona discharge included in the fluctuating current curve is added to the fluctuating current curve, which is sufficiently longer than the duration of the corona discharge, and the high voltage electrode and the object to be coated. Since a comparative current curve delayed by a time t1 sufficiently shorter than the current change time due to approach to an object (operation of the electrostatic coating device) was set, noise due to corona discharge and a gradual increase in current value due to operation of the electrostatic coating device were set. For, the comparison current curve and the fluctuation current curve do not intersect. Therefore, by detecting the time point at which the comparative current curve and the variable current curve intersect, only the occurrence of spark discharge can be reliably detected, and the electrostatic coating device can be operated efficiently.
【００２６】図４ないし図６は、本発明の他の実施例を
示すもので、図３は火花放電検知装置のブロック図、図
４（ａ）〜（ｇ）は火花放電検知装置を構成する各回路
の出力波形図、図５は火花放電検知装置全体の回路構成
図である。図中、図１ないし図３と同一構成をとる部分
については同一符号を付している。図３中、検出回路
１、フィルター回路２、増幅回路３は図１に示す第１の
実施例と同じであり、図４中の（ａ）（ｂ）（ｃ）の各
波形は、図２の（ａ）（ｂ）（ｃ）の各波形と同様であ
る。以下、第１の実施例と異なる点を中心に説明する。4 to 6 show another embodiment of the present invention. FIG. 3 is a block diagram of a spark discharge detecting device, and FIGS. 4 (a) to 4 (g) constitute a spark discharge detecting device. FIG. 5 is an output waveform diagram of each circuit, and FIG. 5 is a circuit configuration diagram of the entire spark discharge detection device. In the figure, parts having the same configurations as those in FIGS. 1 to 3 are designated by the same reference numerals. 3, the detection circuit 1, the filter circuit 2, and the amplification circuit 3 are the same as those in the first embodiment shown in FIG. 1, and the waveforms (a), (b), and (c) in FIG. The waveforms of (a), (b) and (c) are the same. Hereinafter, the points different from the first embodiment will be mainly described.
【００２７】増幅回路１３の出力は、加算回路１６及び
微分回路２１に入力される。加算回路１６は、予め設定
回路１５により設定された設定値ｄを、前記増幅回路１
３の電流信号に加算する。設定回路１５により設定され
る設定値ｄは、変動電流に含まれるコロナ放電の立上が
り値より大きい値とする。従って、加算回路１６から出
力される電流信号は図５（ｄ）のような電流曲線とな
る。The output of the amplifier circuit 13 is input to the adder circuit 16 and the differentiator circuit 21. The adder circuit 16 calculates the set value d set by the setting circuit 15 in advance from the amplifier circuit 1
Add to the current signal of 3. The set value d set by the setting circuit 15 is set to a value larger than the rising value of corona discharge included in the fluctuating current. Therefore, the current signal output from the adder circuit 16 has a current curve as shown in FIG.
【００２８】微分回路２１は、増幅回路１３からの出力
信号を微分し、変動電流中において波形の立上がりの変
化の速い部分の変化分の大きさを出力する。この微分回
路２１の出力波形は微分値比較回路２２に入力され、設
定回路２３により予め設定された設定値と比較し、この
設定値より大きい場合に保持信号を出力する（図４
（ｅ））。設定回路２３で設定される設定値は、コロナ
放電による変化量より小さい値とし、コロナ放電の発生
を確実に検知できるようにする。The differentiating circuit 21 differentiates the output signal from the amplifying circuit 13 and outputs the magnitude of the change in the portion where the rising edge of the waveform changes rapidly in the fluctuating current. The output waveform of the differentiating circuit 21 is input to the differential value comparing circuit 22, is compared with a preset value set by the setting circuit 23, and if it is larger than this preset value, a holding signal is output (FIG. 4).
(E)). The set value set by the setting circuit 23 is set to a value smaller than the amount of change due to corona discharge, so that the occurrence of corona discharge can be reliably detected.
【００２９】前記加算回路１６の出力信号及び微分値比
較回路２２の保持信号は、保持回路（ピークホールド回
路）２４に入力され、前記保持信号に対応して、変動電
流信号をコロナ放電の持続時間より長く、被塗装物と高
電圧電極とが相対的に移動することにより両者の距離変
化に応じて負荷電流が変化する時間より充分短い時間ｔ
１、具体的には数１０μ秒〜数ｍ秒、出力信号を保持す
る（図４（ｆ））。The output signal of the adder circuit 16 and the hold signal of the differential value comparison circuit 22 are input to the hold circuit (peak hold circuit) 24, and the fluctuating current signal is changed to the duration of corona discharge corresponding to the hold signal. A time t that is longer and sufficiently shorter than the time required for the load current to change according to the distance change between the object to be coated and the high-voltage electrode due to relative movement.
1. Specifically, the output signal is held for several tens of microseconds to several milliseconds (FIG. 4 (f)).
【００３０】保持回路２４の出力信号と前記増幅回路１
３の出力信号は比較回路１７に入力され、図５（ｇ）に
示すように、図５（ｄ）と図５（ｆ）の電流信号同士が
常時比較され、増幅回路１３からの出力信号の方が大き
くなるとき（図５（ｄ）の変動電流曲線と図５（ｆ）の
比較電流曲線との交差する時点）、火花放電発生と検知
して警報信号を比較回路１７から出力する。この警報信
号により、第１の実施例と同様に例えば図７に示した高
電圧電極側と低電圧端子（接地）間に接続された高電圧
スイッチ３を制御回路４の信号によりオンさせ、火花放
電の発生を未然に防止する。The output signal of the holding circuit 24 and the amplifier circuit 1
The output signal of No. 3 is input to the comparison circuit 17, and the current signals of FIG. 5D and FIG. 5F are constantly compared with each other as shown in FIG. When it becomes larger (when the fluctuating current curve of FIG. 5D and the comparative current curve of FIG. 5F cross each other), the occurrence of spark discharge is detected and an alarm signal is output from the comparison circuit 17. With this alarm signal, the high-voltage switch 3 connected between the high-voltage electrode side and the low-voltage terminal (ground) shown in FIG. 7, for example, is turned on by a signal from the control circuit 4 as in the first embodiment, and a spark is generated. Prevents discharge from occurring.
【００３１】図６は火花放電検知装置の具体的な回路を
示すもので、図３と同一構成をとる部分については同一
符号を付してその詳細な説明を省略する。微分回路２１
は、増幅回路１３の出力側に接続された抵抗１４１と、
該抵抗１４１に直列接続されたコンデンサ１４２と、該
コンデンサに入力側を接続した演算増幅器１４３、演算
増幅器１４３に対して並列に接続された抵抗１４４とか
ら構成され、負荷電流（変動電流）ｉの変化成分を出力
している。FIG. 6 shows a specific circuit of the spark discharge detecting device. The parts having the same configurations as those in FIG. 3 are designated by the same reference numerals and the detailed description thereof will be omitted. Differentiator circuit 21
Is a resistor 141 connected to the output side of the amplifier circuit 13,
It is composed of a capacitor 142 connected in series with the resistor 141, an operational amplifier 143 having an input side connected to the capacitor 141, and a resistor 144 connected in parallel to the operational amplifier 143. The change component is output.
【００３２】微分値比較回路２２は、微分回路２１の出
力側に接続された抵抗１４５と、設定回路２３の可変端
子に接続された抵抗１４６と、抵抗１４５と抵抗１４６
の一端部をそれぞれ入力側とする演算増幅器１４７とか
ら構成されている。また、設定回路２３の構成は、前記
設定回路１５若しくは設定回路１８と同一である。微分
値比較回路２２においては、 前記微分回路２１と設定
回路２３からの出力信号を比較し、微分回路２１からの
出力信号が大きいとき、コロナ放電ないし火花放電の発
生と検知して検知信号を出力する。The differential value comparison circuit 22 has a resistor 145 connected to the output side of the differential circuit 21, a resistor 146 connected to the variable terminal of the setting circuit 23, a resistor 145 and a resistor 146.
And an operational amplifier 147 having one end as an input side, respectively. The configuration of the setting circuit 23 is the same as that of the setting circuit 15 or the setting circuit 18. In the differential value comparing circuit 22, the output signals from the differentiating circuit 21 and the setting circuit 23 are compared, and when the output signal from the differentiating circuit 21 is large, it is detected that corona discharge or spark discharge has occurred, and a detection signal is output. To do.
【００３３】保持回路２４は、保持時間設定回路２４ａ
とピークホールド回路２４ｂとから構成されている。保
持時間設定回路２４ａは、微分値比較回路２２の出力側
に接続された抵抗１４８と、該抵抗１４８と直列に接続
されたコンデンサ１４９、該コンデンサ１４９に一端側
を接続し他端側を接地した抵抗１５０と、抵抗１５０と
コンデンサ１４９との接続点を入力側とした演算増幅器
１５１と、演算増幅器１５１の入力側と定電圧源＋Ｖと
の間に介在させた抵抗１５２と、演算増幅器１５１の入
力側と接地との間に介在させた抵抗１５３と、演算増幅
器１５１に並列に接続したコンデンサ１５４とから構成
され、前記微分値比較回路２２からの出力があったとき
次段のピークホールド回路２４ｂの保持時間を設定す
る。ピークホールド回路２４ｂは、加算回路１６の出力
側に接続された抵抗１５５と、該抵抗１５５に接続され
た演算増幅器１５６、演算増幅器１５６の出力側に接続
された抵抗１５７と、該抵抗１５７と前記保持時間設定
回路２４ａの演算増幅器１５１の出力側との間に介在さ
せカソード側が演算増幅器１５１側となるように接続さ
れたダイオード１５８と、ダイオード１５８のアノード
側をベースに接続しドレインを演算増幅器１５６の出力
側，ソースを演算増幅器１５９の入力側にそれぞれ接続
したトランジスタ１６０と、演算増幅器１５９の入力側
と接地との間に介在させたコンデンサ１６１と、前記演
算増幅器１５６の入力側と演算増幅器１５９の出力側と
の間に介在させた抵抗１６２とから構成され、前記微分
値比較回路２２からの出力が無ければ加算増幅回路１６
からの出力をそのまま出力し、前記微分値比較回路２２
からの出力があればその時の加算増幅回路１６からの出
力を一定時間持続出力させる。The holding circuit 24 is a holding time setting circuit 24a.
And a peak hold circuit 24b. The holding time setting circuit 24a has a resistor 148 connected to the output side of the differential value comparison circuit 22, a capacitor 149 connected in series with the resistor 148, one end of the capacitor 149, and the other end of which is grounded. The input of the resistor 150, the operational amplifier 151 having the connection point of the resistor 150 and the capacitor 149 as the input side, the resistor 152 interposed between the input side of the operational amplifier 151 and the constant voltage source + V, and the input of the operational amplifier 151. Of the resistor 153 interposed between the side and the ground, and a capacitor 154 connected in parallel to the operational amplifier 151. When the differential value comparison circuit 22 outputs, the peak hold circuit 24b of the next stage receives the output. Set the retention time. The peak hold circuit 24b includes a resistor 155 connected to the output side of the adder circuit 16, an operational amplifier 156 connected to the resistor 155, a resistor 157 connected to the output side of the operational amplifier 156, the resistor 157, and the resistor 157. A diode 158 that is interposed between the holding time setting circuit 24a and the output side of the operational amplifier 151 and is connected so that the cathode side is the operational amplifier 151 side, and the anode side of the diode 158 is connected to the base and the drain is the operational amplifier 156. Of the operational amplifier 159, the input side of which is connected to the input side of the operational amplifier 159, the capacitor 161 interposed between the input side of the operational amplifier 159 and the ground, and the input side of the operational amplifier 156 and the operational amplifier 159. Of the resistor 162 interposed between the differential value comparing circuit 22 and Without the force summing amplifier circuit 16
Output from the differential value comparison circuit 22
If there is an output from, the output from the addition amplification circuit 16 at that time is continuously output for a fixed time.
【００３４】本実施例によれば、高電圧電極を流れる電
流を常時検知することにより変動電流曲線を設定し、こ
の変動電流曲線中に含まれるコロナ放電の立上がり値よ
り大きい値を前記変動電流曲線に加算するとともに、前
記変動電流曲線の微分値が予め設定した設定値を越えた
場合に前記変動電流曲線の値を前記コロナ放電の持続時
間より長い時間保持する比較電流曲線を設定したので、
コロナ放電によるノイズ及び静電塗装装置の運転による
緩やかな電流値の増加については、比較電流曲線と変動
電流曲線とが交差することがない。従って、比較電流曲
線と前記変動電流曲線とが交差する時点を検知すること
により、火花放電発生のみを確実に検知することがで
き、静電塗装装置を効率良く運転することができる。According to this embodiment, the fluctuating current curve is set by constantly detecting the current flowing through the high voltage electrode, and the fluctuating current curve is set to a value larger than the rising value of corona discharge included in the fluctuating current curve. In addition to the above, since the differential current value of the fluctuating current curve exceeds the preset value, the value of the fluctuating current curve is set to be a comparative current curve for a longer time than the duration of the corona discharge.
Regarding the noise due to corona discharge and the gradual increase in current value due to the operation of the electrostatic coating device, the comparative current curve and the fluctuating current curve do not intersect. Therefore, by detecting the time point at which the comparative current curve and the variable current curve intersect, only the occurrence of spark discharge can be reliably detected, and the electrostatic coating device can be operated efficiently.
【００３５】[0035]
【発明の効果】本発明によれば、負荷電流を常時検知す
ることにより求められる変動電流曲線に対し、この変動
電流に含まれるコロナ放電によるノイズ及び静電塗装装
置の運転による緩やかな電流値の増加分と交差しないよ
うな比較電流曲線を設定し、この比較電流曲線と前記変
動電流曲線とが交差する時点を火花放電発生と検知する
ので、コロナ放電を火花放電として検知することを防ぐ
ので、火花放電を確実に検知することができ、火花放電
の発生を防止しつつ効率良く塗装を行なうことができ
る。According to the present invention, with respect to the fluctuating current curve obtained by constantly detecting the load current, noise due to corona discharge included in this fluctuating current and a gentle current value due to the operation of the electrostatic coating apparatus are obtained. By setting a comparative current curve that does not intersect with the increment and detecting the time when this comparative current curve and the variable current curve intersect as spark discharge occurrence, it is possible to prevent detecting corona discharge as spark discharge, The spark discharge can be reliably detected, and the coating can be efficiently performed while preventing the spark discharge from being generated.
【図１】 本発明に係る火花放電検知装置の一実施例を
示すブロック図である。FIG. 1 is a block diagram showing an embodiment of a spark discharge detection device according to the present invention.
【図２】 （ａ）ないし（ｆ）は図１の火花放電検知装
置を構成する各回路の出力波形図である。2 (a) to (f) are output waveform diagrams of each circuit constituting the spark discharge detection device of FIG.
【図３】 図１の火花放電検知装置の回路図である。FIG. 3 is a circuit diagram of the spark discharge detection device in FIG.
【図４】 本発明に係る火花放電検知装置の他の実施例
を示すブロック図である。FIG. 4 is a block diagram showing another embodiment of the spark discharge detection device according to the present invention.
【図５】 （ａ）ないし（ｇ）は図４の火花放電検知装
置を構成する各回路の出力波形図である。5 (a) to 5 (g) are output waveform diagrams of each circuit constituting the spark discharge detection device of FIG.
【図６】 図４の火花放電検知装置の回路図である。6 is a circuit diagram of the spark discharge detection device of FIG.
【図７】 静電塗装装置の構成説明図である。FIG. 7 is a structural explanatory view of an electrostatic coating device.
１…直流高電圧電源装置、 ２…高電圧電極、 ３…高
電圧スイッチ、 ４…制御回路、 ５…被塗装物、 １
１…検出回路、 １２…フィルター回路、１３…増幅回
路、 １４…遅延回路、 １５…設定回路、 １６…加
算回路、１７…比較回路、 ２１…微分回路、 ２３…
設定回路、 ２４…保持回路、Ｅ…高電圧発生器1 ... DC high-voltage power supply device, 2 ... High-voltage electrode, 3 ... High-voltage switch, 4 ... Control circuit, 5 ... Object to be coated, 1
DESCRIPTION OF SYMBOLS 1 ... Detection circuit, 12 ... Filter circuit, 13 ... Amplification circuit, 14 ... Delay circuit, 15 ... Setting circuit, 16 ... Addition circuit, 17 ... Comparison circuit, 21 ... Differentiation circuit, 23 ...
Setting circuit, 24 ... Holding circuit, E ... High voltage generator
Claims (4)
を常時検知することにより変動電流曲線を設定し、該変
動電流曲線中に含まれるコロナ放電の立上がり値より大
きい値を前記変動電流曲線に加算するとともに前記コロ
ナ放電の持続時間より長く且つ前記高電圧電極と被塗装
物との接近による電流変化時間より短い時間遅らせた比
較電流曲線を設定し、該比較電流曲線と前記変動電流曲
線とが交差する時点を火花放電発生と検知することを特
徴とする静電塗装装置の高電圧電極に於ける火花放電検
知方法。1. A fluctuating current curve is set by constantly detecting a current flowing through a high voltage electrode of an electrostatic coating device, and a value larger than a rising value of corona discharge included in the fluctuating current curve is set to the fluctuating current curve. And a comparative current curve which is delayed by a time longer than the duration of the corona discharge and shorter than the current change time due to the approach of the high voltage electrode and the object to be coated, the comparative current curve and the fluctuating current curve being set. A method for detecting spark discharge in a high-voltage electrode of an electrostatic coating device, which is characterized in that a spark discharge is detected at the time when the two intersect.
変動を検出する検出器と、該検出器から出力される信号
を、前記検出器で検出されるコロナ放電の持続時間より
長く且つ前記高電圧電極と被塗装物との接近による電流
変化時間より短い時間遅延させる遅延回路と、前記コロ
ナ放電の立上がり値より大きい値を前記遅延回路の出力
に加算する加算器と、該加算器の出力信号と前記検出器
の出力信号とを比較する比較回路と、を具備する静電塗
装装置の高電圧電極に於ける火花放電検知装置。2. A detector for detecting fluctuations in current flowing through a high voltage electrode of an electrostatic coating device, and a signal output from the detector having a duration longer than the duration of corona discharge detected by the detector. A delay circuit for delaying a time shorter than the current change time due to the approach of the high voltage electrode and the object to be coated, an adder for adding a value larger than the rising value of the corona discharge to the output of the delay circuit, and an output of the adder A spark discharge detection device in a high voltage electrode of an electrostatic coating device, comprising: a comparison circuit for comparing a signal with an output signal of the detector.
を常時検知することにより変動電流曲線を設定し、該変
動電流曲線中に含まれるコロナ放電の立上がり値より大
きい値を前記変動電流曲線に加算するとともに、前記変
動電流曲線の微分値が予め設定した設定値を越えた場合
に前記変動電流曲線の値を前記コロナ放電の持続時間よ
り長い時間保持する比較電流曲線を設定し、該比較電流
曲線と前記変動電流曲線とが交差する時点を火花放電発
生と検知することを特徴とする静電塗装装置の高電圧電
極に於ける火花放電検知方法。3. A fluctuating current curve is set by constantly detecting a current flowing through a high voltage electrode of an electrostatic coating device, and a value larger than the rising value of corona discharge included in the fluctuating current curve is set to the fluctuating current curve. In addition, when the differential value of the fluctuating current curve exceeds a preset value, a comparative current curve that holds the value of the fluctuating current curve for a time longer than the duration of the corona discharge is set, and the comparison A method for detecting spark discharge in a high-voltage electrode of an electrostatic coating device, comprising detecting a time point at which a current curve and the fluctuating current curve intersect as occurrence of spark discharge.
変動を検出する検出器と、該検出器から出力される信号
を微分する微分回路と、該微分回路の出力を予め設定し
た値と比較する微分値比較回路と、前記検出器で検出さ
れるコロナ放電の立上がり値より大きい値を前記検出器
の出力に加算する加算器と、前記微分値比較回路の出力
信号により、前記検出器で検出されるコロナ放電の持続
時間より長い時間だけ前記加算器の出力を保持する保持
回路と、該保持回路の出力信号と前記検出器の出力信号
とを比較する比較回路と、を具備する静電塗装装置の高
電圧電極に於ける火花放電検知装置。4. A detector for detecting current fluctuations flowing through a high voltage electrode of an electrostatic coating device, a differentiation circuit for differentiating a signal output from the detector, and a preset value for the output of the differentiation circuit. A differential value comparison circuit for comparison, an adder for adding a value larger than the rising value of corona discharge detected by the detector to the output of the detector, and an output signal of the differential value comparison circuit for the detector Electrostatic comprising a holding circuit that holds the output of the adder for a time longer than the duration of the detected corona discharge, and a comparison circuit that compares the output signal of the holding circuit with the output signal of the detector. Spark discharge detection device for high voltage electrodes of coating equipment.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP4100177A JP2546571B2 (en) | 1992-03-27 | 1992-03-27 | Spark discharge detection method and device for high voltage electrode of electrostatic coating device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP4100177A JP2546571B2 (en) | 1992-03-27 | 1992-03-27 | Spark discharge detection method and device for high voltage electrode of electrostatic coating device |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH05269408A true JPH05269408A (en) | 1993-10-19 |
| JP2546571B2 JP2546571B2 (en) | 1996-10-23 |
Family
ID=14267034
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP4100177A Expired - Lifetime JP2546571B2 (en) | 1992-03-27 | 1992-03-27 | Spark discharge detection method and device for high voltage electrode of electrostatic coating device |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2546571B2 (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2010022933A (en) * | 2008-07-18 | 2010-02-04 | Anest Iwata Corp | Control method enabling to avoid overcurrent anomaly in electrostatic coating |
| JP2020142204A (en) * | 2019-03-07 | 2020-09-10 | Ｊｆｅアドバンテック株式会社 | Electrostatic coating device, monitoring device and electrostatic coating method |
-
1992
- 1992-03-27 JP JP4100177A patent/JP2546571B2/en not_active Expired - Lifetime
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2010022933A (en) * | 2008-07-18 | 2010-02-04 | Anest Iwata Corp | Control method enabling to avoid overcurrent anomaly in electrostatic coating |
| JP2020142204A (en) * | 2019-03-07 | 2020-09-10 | Ｊｆｅアドバンテック株式会社 | Electrostatic coating device, monitoring device and electrostatic coating method |
Also Published As
| Publication number | Publication date |
|---|---|
| JP2546571B2 (en) | 1996-10-23 |
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