JPH01148856U

JPH01148856U -

Info

Publication number: JPH01148856U
Application number: JP4597088U
Authority: JP
Priority date: 1988-04-05
Filing date: 1988-04-05
Publication date: 1989-10-16
Anticipated expiration: 2003-04-05
Also published as: JPH0628690Y2

Description

[Brief explanation of the drawing]

第１図：本考案の一実施例を示すブロツク図。
第２図：被検金属板の表面粗度により、漏洩磁束
成分信号が変化する一例を示すグラフ。第３図：
被検金属板の通板速度により漏洩磁束検出信号が
変化する例を示すグラフ。第４図：磁界強度によ
り漏洩磁束検出信号が変化する例を示すグラフ。
第５図：ギヤツプにより漏洩磁束信号が変化する
例を示すグラフ。１……被検金属板、２……磁化器、３……ロー
ル、４……検出器、５……ギヤツプ間隔調整装置
、６……ギヤツプセンサー、７……帯域フイルタ
ー、８……通板速度検出器、９……アンプ、１０
……変換器、１１……欠陥信号、１２……被検金
属板自体の漏洩信号、１３……信号処理装置、１
４……レベル値、１５……比較器、１６……設定
器、１７……プリセツト器、１８……磁化器電源
、１９……電流計、２０……設定器。 FIG. 1: A block diagram showing an embodiment of the present invention.
FIG. 2: A graph showing an example of how the leakage magnetic flux component signal changes depending on the surface roughness of the metal plate to be tested. Figure 3:
2 is a graph showing an example in which a leakage magnetic flux detection signal changes depending on the passing speed of a metal plate to be inspected. FIG. 4: Graph showing an example of how the leakage magnetic flux detection signal changes depending on the magnetic field strength.
Figure 5: Graph showing an example of how the leakage magnetic flux signal changes due to a gap. 1...Metal plate to be tested, 2...Magnetizer, 3...Roll, 4...Detector, 5...Gap interval adjustment device, 6...Gap sensor, 7...Band filter, 8...Threading speed Detector, 9...Amplifier, 10
...Converter, 11... Defect signal, 12... Leakage signal of the metal plate itself to be tested, 13... Signal processing device, 1
4... Level value, 15... Comparator, 16... Setting device, 17... Presetting device, 18... Magnetizer power supply, 19... Ammeter, 20... Setting device.

Claims

[Scope of utility model registration request]

In a device for detecting flaws by using a detector to detect magnetic flux leaking through a metal plate to be tested due to a magnetic field generated by a magnetizer, a bandpass filter that passes defect components in the signal from the detector and leakage components from the metal plate to be tested itself; An amplifier that amplifies the signal from the band filter, a converter that inputs the signal from the amplifier and separates and detects the defect signal and the leakage signal of the metal plate itself, and the surface of the metal plate that is input separately. A preset device that inputs the roughness signal, threading speed signal, magnetic field strength signal of the magnetizer, and gap signals of the metal to be tested and the detector and outputs the leakage component level value, and a preset device that outputs the leakage component level value and the signal from the converter. A metal comprising a comparator that compares leakage signals of the metal plates themselves to be tested and outputs a difference signal, and a digital gain setting device that inputs the difference signal and changes the gain of an amplifier so that the difference disappears. Board defect detection device.