JPH01178859A - Inspecting apparatus of defect of pipe joint - Google Patents

Abstract

PURPOSE:To judge the quality of a pipe joint precisely in-line by a method wherein measuring heads 7 and 8 are pressed against the opposite ends of the pipe joint in a manufacturing line to determine a potential difference distribution on the whole circumference of an end face of the pipe joint, and measured data thus obtained are computed by a computer. CONSTITUTION:A pipe joint, a test object, is transferred onto a sample stage 55 of a conveyor belt 52 and measuring heads 7 and 8 are pressed against this pipe joint from the opposite sides respectively. On each of the measuring heads 7 and 8, a plurality of terminals used for both direct-current supply and potential difference measurement are disposed concentrically. On the occasion of measurement, a direct current is impressed from two terminals of the aforesaid ones facing each other at an angle of 180 deg. apart, and a potential difference between the opposite terminals adjacent to each of the two terminals is measured. Next, the direct current is impressed from two terminals separated at an angle of 90 deg. from the aforesaid two terminals respectively, and a potential difference except for the one between the terminals in the opposite ends is determined. A potential difference distribution on the whole circumference of the opposite end faces of the pipe joint is determined in this way, measured values thus obtained are processed by a computer, and thereby the presence or absence of a defect of the pipe joint is judged.

Description

【発明の詳細な説明】 〔産業上の利用分野〕 本発明は金属構造物に発生した欠陥を検出する欠陥検出
技術に係り、特に、ガス配管や水道配管に使用される管
継手に生じた欠陥の検出装置に関する。[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to defect detection technology for detecting defects occurring in metal structures, and in particular, defects occurring in pipe joints used for gas piping and water piping. The present invention relates to a detection device.

〔従来の技術〕[Conventional technology]

従来の電気抵抗法、あるいは、ポテンシャル法。 Conventional electrical resistance method or potential method.

によるき裂検出法には、いわゆる、四端子法と呼ばれる
ものがある。それは、一対の給電端子とその内側に一対
の測定端子を一列に配列したものを構造部材の表面を走
査して、電位差分布の変化から欠陥を検出するものであ
る。欠陥の判定は欠陥がないと思われる領域における電
位差を基準電位差とし、それよりも大きい電位差となっ
たところに欠陥があると判定するものである。従って、
四端子法では欠陥の有無及び欠陥のある程度の深さは判
定できるけれども、端子を部材表面で走査しなければな
らず、短時間で欠陥の有無を判定する、或いは、オンラ
インで欠陥を検出することはできないという欠点があっ
た。There is a crack detection method called the so-called four-probe method. In this method, a pair of power supply terminals and a pair of measurement terminals arranged in a line inside the power supply terminals are scanned over the surface of a structural member, and defects are detected from changes in the potential difference distribution. Defect determination is performed by using a potential difference in a region where no defects are expected to be present as a reference potential difference, and determining that a defect exists in areas where the potential difference is larger than the reference potential difference. Therefore,
Although the four-terminal method can determine the presence or absence of a defect and the depth of the defect to a certain extent, it requires scanning the terminal over the surface of the component, making it difficult to determine the presence or absence of a defect in a short time, or to detect the defect online. The drawback was that it was not possible.

他の欠陥検出法として、例えば、超音波探傷法がある。Other defect detection methods include, for example, ultrasonic flaw detection.

超音波探傷法では音響を伝搬するためのカプラントが必
要であり、オンラインで欠陥を検出する場合には、被測
定物をカプラント中に漬ける水浸法の採用が不可欠であ
るが、被測定物を搬送するための装置が大掛りとなり、
実用的ではない。Ultrasonic flaw detection requires a couplant to propagate sound, and when detecting defects online, it is essential to use the water immersion method in which the object to be measured is immersed in the couplant. The equipment for transporting it became large-scale,
Not practical.

〔発明の目的〕[Purpose of the invention]

本発明の目的は管継手に発生した欠陥を製造工程の中で
オンラインで短時間に、且つ、全自動で検出できる装置
を提供することにある。SUMMARY OF THE INVENTION An object of the present invention is to provide a device that can detect defects occurring in pipe joints online in a short time and fully automatically during the manufacturing process.

【発明の概要〕[Summary of the invention]

管継手に発生した欠陥をポテンシャル法により検出でき
るかどうかを検討するために、実際の欠陥を模擬した試
験片を作成し、種々の構造の測定ヘッドを作成して実験
を行った。その結果、欠陥発生位置は管継手を鋳型で作
成するときの湯道の付け根であって、管用テーパねじの
ある管継手の内面側から発生するため、管継手端部で測
定できる構造である円筒形状の測定ヘッドに同心円状に
直流電流供給と電位差測定を兼用した端子を等間隔で、
対称形に少なくとも八個以上の四の倍数の複数個配置す
れば良いことが分かった。しかし。In order to examine whether defects occurring in pipe joints can be detected using the potential method, we created test pieces that simulated actual defects and conducted experiments using measurement heads with various structures. As a result, the defect occurs at the base of the runner when the pipe fitting is made with a mold, and because it occurs from the inner surface of the pipe fitting with the tapered pipe thread, it is found that the defect occurs in the cylindrical tube, which has a structure that can be measured at the end of the pipe fitting. Terminals for both DC current supply and potential difference measurement are arranged concentrically on the shaped measuring head at equal intervals.
It was found that it is sufficient to arrange at least eight or more multiples of four in a symmetrical shape. but.

端子は直流電流供給と電位差測定を兼用しているが、直
流電流を供給する端子では電位降下が著しいため、電位
差測定精度が良くない。そこで、第一に１８０度離度離
向い合う二個の端子から直流電流を印加してその両隣に
ある端子間を除く端子間の電位差を測定し、第二に上記
１８０度離度離向い合う二個の端子からそれぞれ９０度
離れた二個の端子から直流電流を印加して、第一の電位
差測定のとき測定した端子間を除く端子間の電位差を測
定することによって管継手の両端面の全円周上の電位差
分布を求め、それらの比較演算から欠陥深さを判定する
方法を考案した。次に、その測定方法を満足すると共に
、製造工程でインラインで短時間で欠陥検査を行える検
査装置を考案した。The terminal serves both to supply DC current and to measure potential difference, but the potential drop in the terminal that supplies DC current is significant, so the accuracy of potential difference measurement is poor. Therefore, firstly, we applied a DC current from two terminals that are 180 degrees apart and measured the potential difference between the terminals except for the terminals on both sides. By applying a direct current from two terminals that are 90 degrees apart from each other and measuring the potential difference between the terminals excluding the terminals measured during the first potential difference measurement, the potential difference between the two terminals is measured. We devised a method to determine the defect depth by determining the potential difference distribution over the entire circumference and comparing them. Next, we devised an inspection device that satisfies the measurement method and can perform defect inspection in-line in a short time during the manufacturing process.

〔発明の実施例〕[Embodiments of the invention]

以下１本発明の一実施例を説明する。第１図はベルトコ
ンベアに取付けられた多数の試料台の上に載せられて搬
送される管継手を一個ずつ検査する管継手欠陥検査装置
の平面図を示す。本体ベース５１には、被測定物である
管継手を供給するパーツフィーダ５８と、管継手を載せ
る試料台５５を多数取付けたベルトコンベア５２と、パ
ーツフィーダ５８から供給された管継手をベルトコンベ
ア５２上の試料台５５に挿入するための管継手挿入用ガ
イド５６と、管継手挿入用空気シリンダ・１７と、管継
手を試料台上で位置決めするための位に決めストッパー
５７と、ベルトコンベア５２を駆動させるためのコンベ
ア駆動用モータ１５と、直流電流の供給と電位差の測定
を兼用する多数の端子をもつ測定ヘッド７．８をそれぞ
れの軸端に取付けた二個の測定ヘッド用空気シリンダと
１９゜２１と、欠陥ありと判定された管継手をベルトコ
ンベア５２の試料台５５から排除するための欠陥管継手
排出用空気シリンダ２３と、排出された欠陥のある管継
手を収納箱に排出するための排出用シュート６３と、コ
ンベア上の試料台の位置を検出するためのワーク通過セ
ンサ６４とが設けである。An embodiment of the present invention will be described below. FIG. 1 shows a plan view of a pipe fitting defect inspection apparatus that inspects pipe fittings one by one, which are carried on a large number of sample stands attached to a belt conveyor. The main body base 51 includes a parts feeder 58 that supplies pipe fittings as objects to be measured, a belt conveyor 52 on which a large number of sample stands 55 on which pipe fittings are mounted, and a belt conveyor 52 that carries pipe fittings supplied from the parts feeder 58. A pipe fitting insertion guide 56 for inserting into the upper sample stage 55, a pipe fitting insertion air cylinder 17, a positioning stopper 57 for positioning the pipe joint on the sample stage, and a belt conveyor 52 are installed. A conveyor drive motor 15 for driving the conveyor, and two measuring head air cylinders 19 each having a measuring head 7.8 attached to its shaft end, each having a large number of terminals for both supplying direct current and measuring potential differences. 21, a defective pipe fitting discharge air cylinder 23 for removing pipe fittings determined to be defective from the sample stage 55 of the belt conveyor 52, and a defective pipe fitting discharging air cylinder 23 for discharging the discharged defective pipe fittings into a storage box. A discharge chute 63 and a work passage sensor 64 for detecting the position of the sample stage on the conveyor are provided.

初めに、管継手の欠陥検査の大まかな工程を順序を追っ
て示すと、次のようになる。First, the general process for inspecting pipe joints for defects is as follows.

（１）、管継手がパーツフィーダ５８にあることをワー
ク切れセンサ５９で確認。(1) Confirm that the pipe joint is in the parts feeder 58 using the workpiece outage sensor 59.

（２）、試料挿入用ガイド５６に載っている管継手を管
継手挿入用空気シリンダ１７で押し出してベルトコンベ
ア５２上の試料台５５に載せろ。このとき位置決めスト
ッパ５７で自動的に位置決めされる。(2) Push out the pipe fitting placed on the sample insertion guide 56 with the pipe fitting insertion air cylinder 17 and place it on the sample stage 55 on the belt conveyor 52. At this time, the positioning is automatically performed using the positioning stopper 57.

（３）、ベルトコンベア５２を試料台５５の間隔に等し
い距離分だけ駆動して管継手の載った試料台５５を測定
部に移動させる。(3) The belt conveyor 52 is driven by a distance equal to the interval between the sample stands 55 to move the sample stand 55 on which the pipe joint is mounted to the measurement section.

（４）、測定ヘッド７用空気シリンダ１９を駆動して測
定ヘッド７を管継手の一方の端面に押し付ける。(4) Drive the measuring head 7 air cylinder 19 to press the measuring head 7 against one end surface of the pipe joint.

（５）、Ｉｆｆ定ヘッド８用空気シリンダ２１を駆動し
て測定ヘッド８を管継手の他方の端面に押し付ける。(5) Drive the air cylinder 21 for the Iff constant head 8 to press the measuring head 8 against the other end surface of the pipe joint.

（６）、管継手の両端面の周方向の電位差分布を測定す
る。(6) Measure the potential difference distribution in the circumferential direction on both end faces of the pipe joint.

（７）、ｉ位差分布から測定異常品、異常品、欠陥品、
正常晶を判別する。(7) Measured abnormal products, abnormal products, defective products from the i-level difference distribution,
Determine normal crystals.

（８）、ベルトコンベアを試料台の間隔に等しい距離分
だけ駆動して管継手の載った試料台を不良管継手排出部
に移動させる。(8) The belt conveyor is driven by a distance equal to the interval between the sample stands to move the sample stand on which the pipe fitting is placed to the defective pipe fitting discharge section.

（９）５測定異常品、異常品、欠陥品と判別された管継
手を不良管継手排出部で欠陥管継手排出用シリンダ２３
を駆動して排出する。(9) 5 Pipe fittings that have been determined to be abnormally measured, abnormal, or defective are sent to the defective fitting discharging cylinder 23 at the defective fitting discharging section.
is driven and ejected.

（］、０）、ベルトコンベアを試料台の間隔に等しい距
に分だけ駆動して正常な管継手を次の工程に廻す。(], 0), the belt conveyor is driven by a distance equal to the distance between the sample stages, and the normal pipe joint is transferred to the next process.

但し、試料台５５はベルトコンベア５２の上に等間隔で
取付けてあり、管継手挿入用シリンダ１７と測定ヘッド
駆動用シリンダ１９，２１、及び、欠陥管継手排出用シ
リンダ２３はベルトコンベア５２の試料台５５の間隔と
同じ間隔で配置しであるので、上記の一連の工程のうち
、試料挿入用ガイド５６に載っている管継手を管継手挿
入用空気シリンダ１７で押し出してベルトコンベア５２
上の試料台５５に載せる作業と、測定ヘッド７゜８を管
継手の両端面に押し付けて管継手の両端面の周方向の電
位差分布を測定する作業と、測定異常品、異常品、欠陥
品と判別された管継手を不良管継手排出部で欠陥管継手
排出用シリンダ２３を駆動して排出する作業はベルトコ
ンベア５２が電位差分布測定のために停止している時間
帯にほとんど同時に行われることになる。However, the sample stands 55 are mounted on the belt conveyor 52 at equal intervals, and the tube fitting insertion cylinder 17, measurement head drive cylinders 19, 21, and defective tube fitting discharge cylinder 23 are installed on the belt conveyor 52. Since they are arranged at the same intervals as the intervals between the tables 55, in the above series of steps, the pipe fittings placed on the sample insertion guide 56 are pushed out by the pipe fitting insertion air cylinder 17 and transferred to the belt conveyor 55.
The work of placing the sample on the upper sample stage 55, the work of pressing the measurement head 7゜8 against both end faces of the pipe joint to measure the potential difference distribution in the circumferential direction on both end faces of the pipe joint, and measuring abnormal, abnormal, and defective products. The work of driving the defective pipe fitting discharging cylinder 23 to discharge the pipe fittings determined to be defective at the defective pipe fitting discharging section is performed almost simultaneously during the time period when the belt conveyor 52 is stopped for measuring the potential difference distribution. become.

第２図には管継手をベルトコンベア５２に載せる部分の
正面図、第３図には後述するポテンシャル法により欠陥
の有無を判定する測定部の正面図、第４図には欠陥あり
と判定された管継手を排出する部分の正面図を示す。第
１図から第４図により、上記の工程に従って、各部の構
造と動作を説明する。第２図の管継手の挿入部ではパー
ツフィーダ５８の先端部が示しであるが、前述のように
欠陥検査は連続して行なわれるため、先端部には管継手
の有無を確認するためのワーク切れセンサ５９が設けで
ある。ワーク切れセンサ５９は試料挿入用ガイド５６に
載っている管継手の次に検査される管継手を検出できる
位置に配置しである。もし、その次の管継手が無くなっ
た場合には、検査を中断し、新たにパーツフィーダ５８
から管継手が供給されると、自動的に検査を再開するよ
うにシステムが構成されている。試料挿入用ガイド５６
に載っている管継手は、管継手挿入用シリンダ１７の軸
端に取付けた管継手の外径よりもやや小さい円板によっ
て、ベルトコンベア５２の方へ押し出され、試料台５５
の上に載せられる。このとき、ベルトコンベア５２の反
対側には位置決めストッパ５７が配置しであるので、挿
入された管継手の端面部分が位置決めストッパ５７にぶ
つかることによって自動的に位置決めされる。試料台５
５と試料挿入用ガイド５６の形状は管継手よりもやや大
きい孔を中央に開けた直方体を半割りにしたようなもの
であり、管継手の試料台５５への挿入の都合上当然のこ
とながら、試料挿入用ガイド５６の高さは試料台５５よ
りもやや高くしておくことが必要である。第２図には示
してないが、パーツフィーダ５８の先端部分にはワーク
切れセンサ５９と共に、管継手押さえ６０を設けておき
、試料挿入用ガイド５６に載っている管継手をベルトコ
ンベア５２の試料台５５に挿入するときに、次に検査さ
れる管継手が落下しないようにする。また、管継手挿入
用シリンダ１７の軸端に取付けた板の一端をＬ字形に延
ばしておき、管継手を押し出したとき次の管継手がその
板の上に載ってシリンダ１７の軸上に落下しないような
管継手落下防止板６１を設けておく。Fig. 2 is a front view of the part where the pipe fitting is placed on the belt conveyor 52, Fig. 3 is a front view of the measuring section that determines the presence or absence of defects using the potential method described later, and Fig. 4 is a front view of the part where the pipe fitting is placed on the belt conveyor 52. This figure shows a front view of the part where the pipe fitting is discharged. The structure and operation of each part will be explained according to the above steps with reference to FIGS. 1 to 4. The tip of the parts feeder 58 is shown in the insertion part of the pipe fitting in Figure 2, but since defect inspection is performed continuously as described above, there is a workpiece at the tip to check the presence or absence of the pipe fitting. A cut sensor 59 is provided. The workpiece breakage sensor 59 is arranged at a position where it can detect the pipe fitting to be inspected next to the pipe fitting placed on the sample insertion guide 56. If there are no more pipe fittings, the inspection will be interrupted and a new part feeder 58 will be placed.
The system is configured to automatically resume inspection when pipe fittings are supplied. Sample insertion guide 56
The pipe fittings placed on the pipe fittings are pushed toward the belt conveyor 52 by a disc that is slightly smaller than the outer diameter of the pipe fittings attached to the shaft end of the pipe fitting insertion cylinder 17, and are pushed onto the sample stage 55.
It is placed on top of the . At this time, since a positioning stopper 57 is disposed on the opposite side of the belt conveyor 52, the end face portion of the inserted pipe fitting hits the positioning stopper 57 and is automatically positioned. Sample stand 5
5 and the sample insertion guide 56 are shaped like a rectangular parallelepiped cut in half with a hole slightly larger than the pipe joint in the center. It is necessary that the height of the sample insertion guide 56 is slightly higher than the sample stage 55. Although not shown in FIG. 2, a pipe joint holder 60 is provided at the tip of the parts feeder 58 together with a workpiece outage sensor 59, and the pipe joint resting on the sample insertion guide 56 is inserted into the sample on the belt conveyor 52. When inserting into the stand 55, the pipe joint to be inspected next is prevented from falling. In addition, one end of the plate attached to the shaft end of the cylinder 17 for inserting a pipe fitting is extended into an L shape, and when the pipe fitting is pushed out, the next pipe fitting rests on the plate and falls onto the axis of the cylinder 17. A pipe fitting fall prevention plate 61 is provided to prevent the pipe fitting from falling.

第３図は測定部の配置を示す図である。後述する形状の
測定ヘッド７を軸端に取付けた測定ヘッド用空気シリン
ダ１９と、測定される管継手と、測定ヘッド８を軸端に
取付けた測定ヘッド用空気シリンダ２１を水平に一直線
状に配置する。ベルトコンベア５２の内側、すなわち、
試料台５５の直下には測定される管継手や試料台５５の
重みでベルトコンベア５５が垂れ下がらないようにベル
トコンベア支持台６２を設けて、測定ヘッド用空気シリ
ンダ１９．２１と測定ヘッド７．８およびａ定される管
継手が水平に一直線状になるようにする。このとき、測
定ヘッド用空気シリンダ１９は軸端を延ばし切ったとき
に測定ヘッド７の端子の先端が測定される管継手の端面
に丁度接触するような位置に配置するものとし、一方、
測定ヘッド用空気シリンダ２１は軸端を延ばしたときに
測定ヘッド８の端子の先端が十分に余裕を持って管継手
のもう一方の端面に押し付けられるような位置に配置し
て、端子の管継手の端面への押し付け力が十分となるよ
うにする。FIG. 3 is a diagram showing the arrangement of the measuring section. A measuring head air cylinder 19 with a measuring head 7 of a shape to be described later attached to the shaft end, a pipe joint to be measured, and a measuring head air cylinder 21 with a measuring head 8 attached to the shaft end are arranged horizontally in a straight line. do. Inside the belt conveyor 52, that is,
Directly below the sample stand 55, a belt conveyor support stand 62 is provided to prevent the belt conveyor 55 from sagging due to the weight of the pipe fittings to be measured and the sample stand 55, and the measuring head air cylinder 19. 8 and a so that the pipe fittings defined are aligned horizontally. At this time, the measurement head air cylinder 19 shall be placed in such a position that when the shaft end is fully extended, the tip of the terminal of the measurement head 7 will just come into contact with the end surface of the pipe joint to be measured;
The air cylinder 21 for the measuring head is placed in such a position that when the shaft end is extended, the tip of the terminal of the measuring head 8 is pressed against the other end surface of the pipe joint with sufficient margin. Ensure that the pressing force against the end face is sufficient.

第４図は欠陥ありと判定された管継手の排出部である。FIG. 4 shows the discharge section of a pipe joint that was determined to be defective.

測定された管継手の真横に欠陥管継手排出用シリンダ２
３を配置して、その軸端には管継手の外径よりもやや小
さい円板を取付ける。電位差分布測定を終了してこの不
良管継手排出部に搬送されてきた管継手のうち、電位差
分布測定結果により測定異常品、異常品、欠陥品と判別
された管継手については、欠陥管継手排出用シリンダ２
３を駆動して軸端の円板を管継手の端面に押し当てて試
料台５５から横方向に排出する。排出された不良品は排
出用シュート６３に載って不良品収納箱等に排出される
。Cylinder 2 for discharging defective pipe fittings is installed right next to the measured pipe fittings.
3, and a disk slightly smaller than the outside diameter of the pipe joint is attached to the shaft end. Among the pipe fittings that have completed the potential difference distribution measurement and are transported to this defective pipe fitting discharge section, those pipe fittings that are determined to be abnormal, abnormal, or defective based on the potential difference distribution measurement results are discharged as defective pipe fittings. cylinder 2
3 to press the disk at the end of the shaft against the end face of the pipe joint and eject it from the sample stage 55 in the lateral direction. The discharged defective products are placed on a discharge chute 63 and discharged into a defective product storage box or the like.

第５図には管継手検査装置のシステム系統図を示す。検
査装置の各機器の制御と電位差の測定、及び測定された
電位差分布のデータ処理は全て小型のコンピュータ１で
行われる。直流電流の供給と電位差測定を兼用した多数
の端子を配した測定ヘッド７．８の測定する端子の切り
換えはＧＰ−ＴＢインターフェース４を介してコンピュ
ータ１に制御されるマルチプレクサ６により行われ、切
り換えられた端子間の電位差は同じ（ＧＰ−ＩＢインタ
ーフェース４を介してコンピュータ１に制御される微小
電位差計５により測定され、コンピュータ１にデータは
転送される。この場合、電位差測定毎に電位差データを
転送しても良いが、内部には記憶回路をもつ微小電位差
計を使用して電位差分布を測定してから、纏めて油部の
データを転送する方がデータ転送時間が短くて済む。測
定ヘッド７．８への直流電流の供給方法の詳細は後述す
るが、その供給は二台の直流電源１０，１１から電流の
極性を切り換えるためのスイッチング装置１２を介して
マルチプレクサ１３に供給され、ここで測定ヘッド７．
８の電流を供給する端子を切り換えられる。上記のスイ
ッチング装置１２とマルチプレクサ１３はＧＰ−ＩＯゼ
インーフェース９を介してコンピュータ１により制御さ
れる。FIG. 5 shows a system diagram of the pipe joint inspection device. Control of each device of the inspection apparatus, measurement of potential differences, and data processing of the measured potential difference distribution are all performed by the small computer 1. The measuring head 7.8, which is equipped with a large number of terminals that serve both to supply DC current and to measure potential difference, switches the terminals to be measured by a multiplexer 6 controlled by the computer 1 via the GP-TB interface 4. The potential difference between the terminals is the same (measured by a minute potentiometer 5 controlled by the computer 1 via the GP-IB interface 4, and the data is transferred to the computer 1. In this case, the potential difference data is transferred every time the potential difference is measured. However, the data transfer time will be shorter if the potential difference distribution is measured using a minute potentiometer with an internal memory circuit, and then the data of the oil section is transferred all at once.Measurement head 7 The details of the method for supplying DC current to . Head 7.
8 terminals that supply current can be switched. The switching device 12 and multiplexer 13 described above are controlled by the computer 1 via the GP-IO interface 9.

次に、管継手の搬送系統を説明する。管継手搬送用のコ
ンベア駆動用モータ・１５はモータ駆動装置１４により
駆動される。管継手挿入用シリンダ１７、測定ヘッド１
用シリンダ１９．測定ヘッド２用シリンダ２１、欠陥管
継手排出用シリンダ２３はそれぞれ圧縮空気′ｇ２４か
ら供給される圧縮空気により電磁弁１６，１８，２０．
２２を介して駆動される。これらのモータ駆動装置１４
、電磁弁１６，１８，２０，２２と共にワーク切れセン
サ２５とワーク通過センサ２６はＧＰ−ＩＯゼインーフ
ェース９を介してコンピュータ１により制御される。管
継手の端面の電位差分布の測定値や欠陥の有無の判定結
果、及び、測定した管継手の個数や欠陥品の個数はＣＲ
Ｔ２、或いは、プリンタ３に出力される。Next, the transport system of the pipe joint will be explained. A conveyor drive motor 15 for transporting pipe fittings is driven by a motor drive device 14. Pipe fitting insertion cylinder 17, measuring head 1
Cylinder 19. The cylinder 21 for the measurement head 2 and the cylinder 23 for discharging defective pipe joints are operated by the solenoid valves 16, 18, 20, .
22. These motor drive devices 14
, solenoid valves 16, 18, 20, and 22, a workpiece outage sensor 25, and a workpiece passage sensor 26 are controlled by the computer 1 via the GP-IO Zein interface 9. The measured value of the potential difference distribution on the end face of the pipe joint, the determination result of the presence or absence of defects, the number of pipe joints measured, and the number of defective products are CR.
T2 or output to the printer 3.

次に測定ヘッド７．８の構造を第６図に示す。Next, the structure of the measuring head 7.8 is shown in FIG.

測定ヘッドは不導体製材料で作成されており、形状は円
筒形である。その中心軸を中心として同心円上に配置し
た孔に、測定端子と給電端子を兼用した端子を対称に配
置する。ただし、端子の数は四の倍数とする。端子の形
状は、第６図に示したように、先端を円錐形とし、その
後方を円柱形状とし、更に、その後方を上述の円柱形状
よりもやや直径の小さい円柱形状とし、その後端にはネ
ジを切る。ｍｌ定ヘッドに開けられた孔は二段となって
おり、端子の後方の細い円柱形状の部分にコイルバネを
挿入した上で、孔に挿入して、後端のネジにナツトを取
付けることにより、測定ヘッドを管継手の端面に押し付
けたときに多少の凹凸があっても端子の先端が管継手の
端面にきちんと接触できるようになっている。なお、端
子を配置する同心円のピッチ円直径は管継手の外径と内
径の平均よりも小さくする。これは欠陥が管継手の内側
に発生するため、欠陥の検出感度を高くするためである
。なお、測定ヘラ１くが管継手に押し付けられたときに
、測定ヘッドの中心が管継手の中心とできるだけ一致す
るようにするために、測定ヘッドの管継手に当たる側の
中央には円錐台形状の突起を設ける。そのため、突起の
底面側の直径は管継手の内径よりもやや小さめに設定し
ておく。The measuring head is made of non-conducting material and is cylindrical in shape. Terminals serving both as measurement terminals and power supply terminals are symmetrically arranged in holes arranged concentrically around the central axis. However, the number of terminals shall be a multiple of four. As shown in Figure 6, the shape of the terminal is a conical tip, a cylindrical portion behind it, a cylindrical shape with a diameter slightly smaller than the above-mentioned cylindrical shape, and a cylindrical shape at the rear end. Cut the screw. The hole drilled in the ml constant head has two stages, and by inserting a coil spring into the thin cylindrical part at the rear of the terminal, inserting it into the hole, and attaching a nut to the screw at the rear end, Even if there are some irregularities when the measuring head is pressed against the end surface of the pipe joint, the tip of the terminal can properly contact the end surface of the pipe joint. Note that the pitch diameter of the concentric circles in which the terminals are arranged is smaller than the average of the outer diameter and inner diameter of the pipe joint. This is to increase defect detection sensitivity since defects occur inside the pipe joint. In addition, in order to ensure that the center of the measuring head coincides with the center of the pipe fitting as much as possible when the measuring spatula is pressed against the pipe fitting, there is a truncated conical shape in the center of the side of the measuring head that touches the pipe fitting. Provide a protrusion. Therefore, the diameter of the bottom side of the protrusion is set to be slightly smaller than the inner diameter of the pipe joint.

次に管継手端面の周方向の電位差分布から欠陥の有無、
或いは、異常品の判定方法を示す。第７図には第６図の
ような測定ヘッドを用いて測定した管継手の端面におけ
る円周方向の電位差分布の一例を示す。縦軸は電位差Ｖ
（μｖ）、横軸はチャンネル番号である。この場合、欠
陥がないにも拘らず、管継手の形状が内面に管用ネジが
切ってあり、鋳型の上下がずれていたことなどにより電
位差分布は均一ではない。第８図には比較的正常な形状
の管継手に深さが肉厚の５０％の模擬欠陥を導入させた
場合の電位差分布を示す。この場合、８ｃｈの電位差が
大きく、その他のところではほぼ一定である。従って、
８ｃｈを除いた１ｌｃｈ分の電位差の平均を基準電位差
Ｖｏとして電位差比Ｖ　／　Ｖ　ｏ分布を求めると、欠
陥のある８ｃｈの電位差比はＶ／Ｖｏ＝１．１７となる
。このように欠陥がある場合には欠陥の大きさに応じて
電位差比が大きくなる。種々の深さの模擬欠陥をもっ管
継手を用意して電位差比Ｖ／ＶＯと欠陥深さａ／ｌ（ａ
：欠陥深さ　ｔ：肉厚）との関係を求めたところ、第９
図に示すようなものが得られた。Next, the presence or absence of defects can be determined from the circumferential potential difference distribution on the end face of the pipe joint.
Alternatively, a method for determining abnormal products will be shown. FIG. 7 shows an example of the potential difference distribution in the circumferential direction at the end face of a pipe joint measured using the measuring head as shown in FIG. 6. The vertical axis is the potential difference V
(μv), and the horizontal axis is the channel number. In this case, although there were no defects, the potential difference distribution was not uniform because the shape of the pipe joint had pipe threads cut on the inner surface and the mold was misaligned from the top and bottom. FIG. 8 shows the potential difference distribution when a simulated defect with a depth of 50% of the wall thickness is introduced into a relatively normal shaped pipe joint. In this case, the potential difference between the 8 channels is large, and the potential difference is almost constant elsewhere. Therefore,
When the potential difference ratio V/Vo distribution is determined by setting the average of the potential differences for 1lch excluding 8ch as the reference potential difference Vo, the potential difference ratio of the defective 8ch is V/Vo=1.17. In this way, when there is a defect, the potential difference ratio increases depending on the size of the defect. Pipe joints with simulated defects of various depths were prepared, and the potential difference ratio V/VO and defect depth a/l (a
: Defect depth t : Wall thickness), the 9th
The product shown in the figure was obtained.

電位差比Ｖ　／　Ｖ　ｏと欠陥深さａ／ｌとの関係を三
次式で近似すると、 Ｖ　／　Ｖｏ＝　１．０−０．００５８７　ａ　／　ｔ
　＋０．０６４５７　ａ　／　ｔ２＋０．８７４２　ａ
　／　ｔ　３ のように表せる。従って、第６図のような測定ヘッドを
用いて管継手の端面の円周方向の電位差分布を測定すれ
ば、第９図のような関係曲線、或いは、上式から欠陥深
さを自動的に判定することができる。ただし、実際の検
査で上式により欠陥深さを判定していると時間が掛る。Approximating the relationship between the potential difference ratio V/Vo and the defect depth a/l using a cubic equation, V/Vo= 1.0-0.00587 a/t
+0.06457 a / t2+0.8742 a
/ t 3 It can be expressed as follows. Therefore, if the potential difference distribution in the circumferential direction of the end face of a pipe joint is measured using a measurement head as shown in Fig. 6, the defect depth can be automatically determined from the relationship curve shown in Fig. 9 or from the above equation. can be determined. However, in actual inspection, determining the defect depth using the above formula takes time.

そこで、実用上は欠陥の有無だけを判定するものとする
。判定基準であるが、管継手の内径側の管用ネジを含め
た板厚の５０％を許容限界とすると、そのときの電位差
比はＶ／Ｖｏ　＝　１　、１０となるので、測定された
電位差比がＶ／Ｖｏ＜１．１０であれば欠陥無し、Ｖ／
Ｖｏ　＜１　、１０であれば欠陥有りと判別すれば良い
。Therefore, in practice, only the presence or absence of defects is determined. As for the judgment criteria, if 50% of the plate thickness including the pipe thread on the inner diameter side of the pipe joint is the allowable limit, the potential difference ratio at that time will be V/Vo = 1, 10, so the measured potential difference ratio If V/Vo<1.10, there is no defect, V/
If Vo <1, 10, it may be determined that there is a defect.

ところが、実際に製造される管継手では、欠陥はなくて
も形状が異常であるものがままある。その−例は、鋳物
で作られた管継手の外径中心と、内径側の機械加工によ
る管用ネジの中心が一致しないとか、上下の鋳型のずれ
が大きかったために出来上がった管継手に段差が生じた
とか、横方向に鋳型がずれていたために管継手に段差が
生じたとか、鋳造時に巣ができたとか言ったものがある
。However, in the pipe fittings actually manufactured, there are many cases in which the shape is abnormal even if there are no defects. Examples of this are when the outer diameter center of a cast pipe fitting does not match the center of a pipe thread machined on the inner diameter side, or when there is a large misalignment between the upper and lower molds, resulting in a level difference in the finished pipe fitting. In some cases, the mold was misaligned in the horizontal direction, causing a step in the pipe joint, or cavities were formed during casting.

これらのうち、特に問題となるのは管継手の外径中心と
内径中心が一致していないものである。第１０図にその
ような管継手における電位差分布の一例を示す。ネジ中
心が偏心しているため、管継手の肉厚が周方向で異なる
ために、言わば肉厚に応じた電位差分布となっている。Among these, a particular problem is one in which the center of the outer diameter and the center of the inner diameter of the pipe joint do not coincide. FIG. 10 shows an example of the potential difference distribution in such a pipe joint. Since the center of the screw is eccentric, the wall thickness of the pipe joint differs in the circumferential direction, so the potential difference distribution corresponds to the wall thickness.

電位差は５ｃｈ最大値ｖ、、、＝１９６μＶを示し、そ
の対称位置である１ｌｃｈで最小値Ｖ−Ｉｎ　＝　１４
３　μＶを示す。このような場合には前述の方法では欠
陥の有無を判定できない。そこで、一つの方法は、偏心
があるような場合でも欠陥がなければ電位差分布は連続
的に変化するので、測定された電位差の両隣りの電位差
の平均値を基準電位差とすれば良いと考えられる。即ち
、いま、ｉ　　Ｃｈの電位差をＶ、とし、その前後の端
子間、すなわち、（ｉ−１）ｃｈと（ｊ＋１）ａｈの電
位差をＶｔ−ｔ、Ｖ　ｌ＋　ｔとして、電位差比Ｖ　／
　Ｖ　ｏはＶ／Ｖｏ＝２ｖｔ／　（Ｖｔ−１＋Ｖｔ＋ｔ
）で求めるものとする。但し、１＝１２ｃｈの場合には
（ｉ＋１）ｃｈはｌｃｈであり、１＝１ｃｈの場合には
（ｉ−１）Ｃｈは１２ｃｈである。そのようにして第１
ｏ図の電位差分布から求めた電位差比の分布を第１１図
に示す。第１０図に示したように最大電位差となった５
ｃｈの場合、４ｃｈと６ｃｈの電位差の平均から求めた
基準電位差ｖＯは１８２μ■となり、５ｃｈ（７）電位
差比はＶ　／　Ｖ　。The potential difference shows the maximum value v, , = 196 μV for 5ch, and the minimum value V-In = 14 for 1lch, which is the symmetrical position.
3 μV is shown. In such a case, the presence or absence of a defect cannot be determined using the method described above. Therefore, one method is to use the average value of the potential differences on both sides of the measured potential difference as the reference potential difference, since the potential difference distribution will change continuously even if there is eccentricity as long as there is no defect. . That is, let the potential difference of i Ch be V, and the potential difference between the terminals before and after it, that is, between (i-1) ch and (j+1) ah, be Vt-t and V l+ t, and the potential difference ratio V /
Vo is V/Vo=2vt/ (Vt-1+Vt+t
). However, when 1=12ch, (i+1)ch is lch, and when 1=1ch, (i-1)ch is 12ch. In that way, the first
FIG. 11 shows the distribution of the potential difference ratio obtained from the potential difference distribution in FIG. As shown in Figure 10, the maximum potential difference was 5.
In the case of ch, the reference potential difference vO obtained from the average of the potential differences of 4ch and 6ch is 182μ■, and the 5ch (7) potential difference ratio is V/V.

＝１．０８となる。このようにすれば、前述した欠陥有
無の判定基準であるＶ　／　Ｖｏ＜　１　、１０となり
、無欠陥品を欠陥品と誤判断することはなくなる。逆に
、第８図に示した正常な形状の管継手に深さが肉厚の５
ｏ％の模擬欠陥を導入させた場合の電位差分布から改め
て上記のような方法で基準電位差を計算して電位差分布
を求めた結果を第１２図に示す。やはり、８ｃｈの電位
差比が最も大きいが、　Ｖ／Ｖｏ　＝　１　、１９とな
り、８ｃｈを除いた１ｌｃｈ分の電位差の平均を基準電
位差Ｖ。=1.08. In this way, V/Vo<1, 10, which is the criterion for determining the presence or absence of a defect described above, will be satisfied, and a defect-free product will not be mistakenly judged as a defective product. On the other hand, if the normal shape of the pipe joint shown in Figure 8 has a depth of 5.
FIG. 12 shows the results of calculating the reference potential difference using the method described above from the potential difference distribution when o% of simulated defects are introduced to determine the potential difference distribution. Again, the potential difference ratio of 8ch is the largest, but V/Vo = 1, 19, and the average of the potential differences of 1lch excluding 8ch is the reference potential difference V.

として求めた場合のＶ／Ｖｏ＝１．１７よりもやや大き
めの結果となる。The result is slightly larger than V/Vo=1.17 when calculated as V/Vo=1.17.

さて、第１ｏ図に示した管継手は偏心が大きかったもの
である。その最大電位差ｖ、ａ、＝１９６μＶと、最小
電位差Ｖ、ｌｎ＝１４３μＶの比を求めると、Ｖ−ａｘ
／Ｖ−＋ｎ＝１．３７となる。日本工業規格によれば、
管継手の偏心の許容限界は肉厚の８０％である。そのよ
うに偏心した管継手を選びだして電位差分布を求めたと
ころ、最大電位差と最小電位差の比はＶ−ａｘ／Ｖ−＋
ｎ＝１．２５となった。従って、電位差分布を測定して
電位差比分布を求める前に最大電位差と最小電位差の比
を計算して、それがＶ−ａｘ／Ｖ−ｎｎ＞１．２５とな
れば、偏心が大きいものとして排除すれば良い。従って
、この場合には電位差比分布を求める計算は止めて、直
ちに、ベルトコンベアを駆動して良い。Now, the pipe joint shown in Figure 1o has a large eccentricity. The ratio of the maximum potential difference v, a, = 196 μV and the minimum potential difference V, ln = 143 μV is found to be V-ax
/V-+n=1.37. According to Japanese Industrial Standards,
The allowable limit for eccentricity of pipe joints is 80% of the wall thickness. When we selected such an eccentric pipe joint and calculated the potential difference distribution, we found that the ratio of the maximum potential difference to the minimum potential difference was V-ax/V-+
n=1.25. Therefore, before measuring the potential difference distribution and finding the potential difference ratio distribution, calculate the ratio of the maximum potential difference and the minimum potential difference, and if it becomes V-ax/V-nn>1.25, exclude it as a large eccentricity. Just do it. Therefore, in this case, the calculation for determining the potential difference ratio distribution may be stopped and the belt conveyor may be driven immediately.

また、鋳型に欠陥があって管継手に突起物ができた場合
や、上・下の鋳型のずれが大きかったために段差が生じ
た場合や、横方向に鋳型がずれていたために段差が生じ
たような場合には測定ヘッドの端子が正常に管継手の端
面に接触できないので、測定異常を起こすことがある。In addition, if there is a defect in the mold and a protrusion is formed on the pipe joint, if there is a large misalignment between the upper and lower molds, a step occurs, or if the mold is misaligned laterally. In such cases, the terminals of the measuring head cannot properly contact the end face of the pipe joint, which may cause measurement errors.

この場合の実際の測定値は５通常直流電流値として５Ａ
流したときに１６５μＶ程度であるのが、全く端子が管
継手の表面から浮いてしまった場合には数十ｍＶとなり
、不完全接触の場合には数百μ■となる。The actual measured value in this case is 5A as a normal DC current value.
The voltage is about 165 μV when flowing, but it becomes several tens of mV if the terminal is completely lifted from the surface of the pipe joint, and several hundred μV if there is incomplete contact.

或いは、管、継手の表面の凹凸が著しい場合には端子の
押し付け力が弱いために接触抵抗が増大してやはり数百
μＶとなる。従って、電位差分布を測定したときに、上
記のような測定異常を生じた場合には、管継手が異常で
あるのか、接触不良であるのか区別ができないので、再
測定した方が良いことになる。そこで、測定ヘッド７．
８は、−旦、管継手端面から雑して、改めて押し付け直
してから電位差分布を測定する。ただし、測定異常が数
回続いた場合には上記のような欠陥があるものとして、
測定異常品と判別して排除する。Alternatively, if the surface of the tube or joint is significantly uneven, the pressing force of the terminal is weak, resulting in an increased contact resistance of several hundred microvolts. Therefore, if the above-mentioned measurement abnormality occurs when measuring the potential difference distribution, it is not possible to distinguish whether the pipe fitting is abnormal or the connection is poor, so it is better to remeasure. . Therefore, measuring head 7.
In step 8, first, remove the pipe joint from the end face, press it again, and then measure the potential difference distribution. However, if the measurement abnormality continues several times, it is assumed that there is a defect as described above.
Identifies the product as having an abnormal measurement and rejects it.

また、ＳＲ造時に巣ができた場合には見た目には欠陥の
有無を判定できないが、表面の割れた欠陥と同様に電位
差比が大きくなる。鋳造時の巣の大きさを模擬すること
は困難であるので、前述の表面欠陥と同じ判定基僧とし
て電位差比がＶ　／　Ｖ　。In addition, if a cavity is formed during SR manufacturing, the presence or absence of a defect cannot be visually determined, but the potential difference ratio increases as in the case of a cracked surface defect. Since it is difficult to simulate the size of cavities during casting, the potential difference ratio V/V is used as the same judgment criterion as the aforementioned surface defects.

＞１．１０であれば、欠陥品として排除するものとする
。ただし、この場合には、表面欠陥品との区別は排出品
収納箱に排出された管継手を目視によって判別するしか
ない。If >1.10, the product is rejected as a defective product. However, in this case, the only way to distinguish a product from a product with surface defects is to visually identify the pipe joint discharged into the discharge product storage box.

第１３図には第１図に示した管継手検査装置の測定フロ
ーチャートを示す。測定を開始すると、初めに微小電位
差計５などの測定機器のウオームアンプを行う。次に試
運転を行うが、通常は数回繰返し測定するものとする。FIG. 13 shows a measurement flowchart of the pipe joint inspection device shown in FIG. 1. When the measurement is started, the measurement equipment such as the minute potentiometer 5 is first warm-amplified. Next, a trial run is performed, but normally measurements are repeated several times.

この場合、本検査の場合と同じであるが、初めに測定ヘ
ッド７を被測定物である管継手に押し付ける。これは、
前述したように、管継手はコンベアベルト５２の試料台
５５の上に載っており、試料台の管継手長手方向の長さ
は管継手の長さよりも少しだけ大きめに設定しであるの
で、測定ヘッド７と測定ヘッド８を同時に押し付けた場
合、管継手が試料台から落ちてしまう可能性がある。そ
こで、測定ヘッド７駆動用シリンダ１９は軸端を延ばし
切ったときに測定ヘッド７の端子の先端が測定される管
継手の端面に丁度接触するような位置に配置するものと
し。In this case, as in the case of the main inspection, the measuring head 7 is first pressed against the pipe joint, which is the object to be measured. this is,
As mentioned above, the pipe fitting is placed on the sample stand 55 on the conveyor belt 52, and the length of the sample stand in the longitudinal direction of the pipe fitting is set to be slightly larger than the length of the pipe fitting. If the head 7 and measurement head 8 are pressed at the same time, there is a possibility that the pipe joint will fall off the sample stage. Therefore, the cylinder 19 for driving the measuring head 7 is arranged at a position such that when the shaft end is fully extended, the tip of the terminal of the measuring head 7 just contacts the end surface of the pipe joint to be measured.

一方、測定ヘッド用空気シリンダ２１は軸端を延ばした
ときに測定ヘッド８の端子の先端が十分に余裕を持って
管継手のもう一方の端面に押し付けられるような位置に
配置して、端子の管継手の端面への押し付け力が十分と
なるようにしである。On the other hand, the measuring head air cylinder 21 is placed in such a position that when the shaft end is extended, the tip of the terminal of the measuring head 8 is pressed against the other end surface of the pipe joint with sufficient margin. This is done so that the pressing force against the end face of the pipe joint is sufficient.

従って、測定ヘッド７駆動用シリンダ１９を駆動した直
後に測定ヘッド８用空気シリンダ２１を駆動して、測定
される管継手が試料台からほとんど動くことなく、両側
から測定ヘッド７．８が押し付けられるようにする。そ
の後、電位差分布を測定する。そして、測定ヘッド７．
８を管１袖手から離し、この工程を繰返す。Therefore, the air cylinder 21 for the measuring head 8 is driven immediately after the cylinder 19 for driving the measuring head 7 is driven, and the measuring head 7.8 is pressed from both sides without the pipe joint to be measured moving from the sample stage. do it like this. Thereafter, the potential difference distribution is measured. and measuring head 7.
8 from the sleeve of tube 1 and repeat this process.

次に本検査に入ると、ワークの有無を判定する。Next, when entering the main inspection, the presence or absence of a workpiece is determined.

パーツフィーダ５８の先端に取付けたワーク切れセンサ
５９により、検査される管継手が供給されてパーツフィ
ーダ５８の先端にあれば検査し、ない場合には検査装置
を停止する。検査する場合には、統計をとるために供給
された管継手の個数■を積算する。測定に当たっては、
前述の試運転と同様に、初めに測定ヘッド７用シリンダ
１９を駆動して測定ヘッド７を被測定物である管継手に
押し付け、次いで、測定ヘッド８用シリンダ２１を駆動
して測定ヘッド８を管継手に押し付ける。次に、マルチ
プレクサ６や微小電位差計５などにより電位差分布を測
定して、−旦、測定ヘッド７゜８を管継手から離脱させ
る。」り定された電位差分布をチエツクして、測定値に
異常がないがどうかを確認する。異常があった場合には
再度Ｊｌｌ定ヘッド７．８を管継手に押し付け直して電
位差分布を測定する。測定値が正常であったら電位差分
布から欠陥の有無を判定して、コンベア５２を駆動して
、測定された管継手を管継手排出部へ移動させる。ここ
で欠陥があると判定された場合には、欠陥継手排出用シ
リンダ２３を駆動して、管継手をコンベア上の試料台５
５から突き落して排出用シュート６３に入れる。排出用
シュート６３に載った欠陥のある管継手は自由落下して
欠陥品収納箱に収まる。このとき、欠陥品個数Ｋを積算
して欠陥品の頻度度数を記録する。この一連の作業を繰
り返すことにより管継手の欠陥検査を自動的に行う。A workpiece outage sensor 59 attached to the tip of the parts feeder 58 supplies the pipe fitting to be inspected, and if it is at the tip of the parts feeder 58, it is inspected, and if there is none, the inspection device is stopped. When inspecting, add up the number of pipe fittings supplied to collect statistics. When measuring,
Similar to the test run described above, first drive the measuring head 7 cylinder 19 to press the measuring head 7 against the pipe fitting that is the object to be measured, then drive the measuring head 8 cylinder 21 to press the measuring head 8 against the pipe fitting. Press onto the joint. Next, the potential difference distribution is measured using the multiplexer 6, the minute potentiometer 5, etc., and then the measuring head 7.8 is removed from the pipe joint. Check the specified potential difference distribution to see if there are any abnormalities in the measured values. If there is any abnormality, press the Jll constant head 7.8 onto the pipe joint again and measure the potential difference distribution. If the measured value is normal, the presence or absence of a defect is determined from the potential difference distribution, and the conveyor 52 is driven to move the measured pipe fitting to the pipe fitting discharge section. If it is determined that there is a defect here, the defective joint discharge cylinder 23 is driven to remove the pipe joint from the sample stage on the conveyor.
5 and into the discharge chute 63. The defective pipe fittings placed on the discharge chute 63 fall freely and are placed in the defective product storage box. At this time, the number K of defective products is added up to record the frequency of defective products. By repeating this series of operations, defects in pipe joints are automatically inspected.

次に、第１４図と第１５図により電位差分布の測定方法
を示す。第１４図は測定ヘッド７．８における給電と電
位差測定を兼用した端子の配置を示したものである。こ
こでは１２個の端子を配置した測定ヘッドを示した。い
ま、十二時方向にある端子をＡとし、時計回りに９０度
毎にある端子をそれぞれＢ、Ｃ，Ｄとし、十二時と一時
にある端子間をマルチプレクサ６のｌｃｈに接続し、以
下時計回りに１２ｃｈまで接続する。電位差分布測定の
フローチャートを第１５図に示す。電位差分布測定に当
たっては初めに各機器をリセットする。次に直流電源１
０．１１から供給される電流はスイッチング装置１２と
マルチプレクサ１３を介して、初めにＡとＣの端子の間
に電流を供給する。電流を供給された端子の近傍では電
位の低下が著しいので、電位差測定系統が良くない。そ
のため電流を供給された端子とそれの隣の端子との間に
電位差は測定しないものとする。従って、ＡとＣの端子
から電流を供給された場合には、２゜３．４，５，８，
９，１０，１ｌｃｈの８ｃｈ分の電位差を測定する。次
に、スイッチング装置１２により電流の極性を切り換え
て再び上記ａｃｈ分の電位差を測定する。ここで、直流
電流の極性を切り換えて電位差を二回測定する理由は、
電位差測定用の端子の材質を測定される材料の材質が異
なる場合、もし測定される材料に温度分布があると、端
子と測定される材料の間に熱起電力が生じ、測定される
材料そのものも電位差にそれが上載せられるため、精度
良い測定が不可能となる。熱起電力を取り除く方法とし
ては、電流を流していなくても熱起電力は生じているの
で、−度、電流を流して電位差Ｖ＋を測定した後、電流
を切って熱起電力による電位差Ｖｒを測定して、その差
から測定される材料そのものの電位差ＶＮを計算する方
法がある。すなわち、 ＶＮ＝Ｖ＋　　ＶＴ である。別の方法としては、ここで採用しているような
、正の電流を流して電位差Ｖ＋を測定した後、電流の極
性を切り換えて負の電流を流して電位差Ｖ″″を測定し
てその差を求める方法である。Next, a method for measuring the potential difference distribution will be shown in FIGS. 14 and 15. FIG. 14 shows the arrangement of terminals for both power supply and potential difference measurement in the measurement head 7.8. Here, a measuring head with 12 terminals arranged is shown. Now, the terminal at 12 o'clock is designated as A, the terminals at every 90 degrees clockwise are designated as B, C, and D, respectively, and the terminals located at 12 o'clock and 1 o'clock are connected to lch of multiplexer 6, as follows. Connect up to 12 channels clockwise. A flowchart of potential difference distribution measurement is shown in FIG. When measuring potential difference distribution, first reset each device. Next, DC power supply 1
The current supplied from 0.11 through the switching device 12 and the multiplexer 13 initially supplies current between the A and C terminals. The potential difference measurement system is not good because the potential drop is significant near the terminal to which current is supplied. Therefore, it is assumed that no potential difference is measured between the terminal to which current is supplied and the terminal next to it. Therefore, when current is supplied from terminals A and C, 2° 3.4, 5, 8,
Measure the potential difference for 8 channels: 9, 10, and 1lch. Next, the polarity of the current is switched by the switching device 12, and the potential difference corresponding to the ach is measured again. Here, the reason for switching the polarity of the DC current and measuring the potential difference twice is as follows.
If the material of the terminal for potential difference measurement is different from that of the material to be measured, and if there is a temperature distribution in the material to be measured, a thermoelectromotive force will be generated between the terminal and the material to be measured, causing the material to be measured to This is added to the potential difference, making accurate measurement impossible. As a method to remove thermoelectromotive force, since thermoelectromotive force is generated even when no current is flowing, run current for -degrees and measure the potential difference V+, then turn off the current and measure the potential difference Vr due to thermoelectromotive force. There is a method of measuring and calculating the potential difference VN of the measured material itself from the difference. That is, VN=V+VT. Another method, as used here, is to flow a positive current and measure the potential difference V+, then switch the polarity of the current and flow a negative current to measure the potential difference V''''. This is a method to find.

すなわち、 ■＋＝ＶＴ＋ＶＮ Ｖ−＝Ｖｒ　　Ｖ、ｖ であるので。That is, ■+=VT+VN V-=Vr　V,v Because it is.

ＶＮ＝　（Ｖ＋−Ｖ−）／２ により測定される材料そのものの電位差ＶＮを計算でき
る。この方法では結局二回電位差を測定することになる
ので、上記の方法よりも精度が良くなる利点がある。The potential difference VN of the material itself measured by VN=(V+-V-)/2 can be calculated. Since this method ends up measuring the potential difference twice, it has the advantage of being more accurate than the above method.

ＡとＣの端子から電流を供給して２，３，４゜５．８．
９，１０，１ｌｃｈの電位差を測定し終えると、次に、
電流供給先切り換え用のマルチプレクサ１３により電流
をＢとＤの端子から電流を供給して、同じように１．６
，７，１２ｃｈの四ｃｈ分の電位差を測定する。以上の
一連の作業を測定ヘッド７と８の両方の端子のすべてに
ついて行うことにより、管継手の両端面の円周方向の電
位差分布が測定される。Supply current from terminals A and C to 2, 3, 4 degrees 5.8.
After measuring the potential difference of 9, 10, and 1lch, next,
The current is supplied from the B and D terminals by the multiplexer 13 for switching the current supply destination, and the current is 1.6 in the same way.
, 7, and 12 channels. By performing the above series of operations for all terminals of both measurement heads 7 and 8, the potential difference distribution in the circumferential direction on both end faces of the pipe joint is measured.

第１６図に電位差測定系統のより詳細な配線図を示す。FIG. 16 shows a more detailed wiring diagram of the potential difference measurement system.

測定ヘッド７．８のそれぞれ十二個の端子はすべてマル
チプレクサ６に接続され、上述したＡ、Ｂ、Ｃ，Ｄの四
個の端子は電位差測定用のマルチプレクサ６と共に、電
流供給先切り換え用のマルチプレクサ１３にも接続され
る。All twelve terminals of the measurement head 7.8 are connected to a multiplexer 6, and the four terminals A, B, C, and D mentioned above are connected to the multiplexer 6 for measuring the potential difference and the multiplexer for switching the current supply destination. 13 is also connected.

第１７図には電流供給系統の具体的な配線図を示す。ス
イッチング装置１２とマルチプレクサ１３は、それぞれ
、二個の電磁リレースイッチで構成されている。スイッ
チング装置１２はここでは二極のリレーを用いており、
コモン側をマルチプレクサ１３に接続して、切り換え側
に直流電源の正負を接続するが、二組のリレーでは正負
を逆に配線することにより、電極リレースイッチオン、
オフしたときにコモン側の極性が切り替わるようにする
。マルチプレクサ１３では三極のリレーを用いており、
コモン側をスイッチング装置１２に接続して、切り換え
側をＡとＢ、ＣとＤに接続して、電磁リレースイッチを
オン、オフしたときに電流供給先がＡとＣ１または、Ｂ
とＤに切り替わるようにする。スイッチング装置１２と
、マルチプレクサ１３の駆動部はいずれも駆動電源６９
との接続をフォトカプラ６５．６６．６７．６８で行い
、フォトカプラはＧＰ−ＩＯインターフェース９を介し
てコンピュータ１により制御する。この電位差ｊＩす定
の実際の運用のフローチャートを第１８図に示す。初め
に各機器をリセッＩ・する。この状態ではスイッチング
装置１２とマルチプレクサ１３はいずれもＯＦＦである
。この状態では直流電源１０．１１から供給される電流
はＡとＣの端子の間に電流が供給される。２，３，４，
５゜８．９，１０，１ｌｃｈの電位差を測定すると、次
にスイッチング装置１２をオンにして電流の極性を切り
換えて、再度２，３，４，５，８，９゜１０．１ｌｃｈ
の電位差を測定する。次に、スイッチング装置１２をオ
ンにし、電流供給先切り換え用のマルチプレクサ１３を
オンにして電流をＢとＤの端子から電流を供給して、１
，６，７゜１２ｃｈの電位差を測定すると、次にスイッ
チング装置１２をオンにして電流の極性を切り換えて、
再度１，６，７，１２ｃｈの電位差を測定する。FIG. 17 shows a specific wiring diagram of the current supply system. The switching device 12 and the multiplexer 13 each include two electromagnetic relay switches. The switching device 12 here uses a two-pole relay,
The common side is connected to the multiplexer 13, and the positive and negative terminals of the DC power supply are connected to the switching side. However, by reversing the wiring for the two sets of relays, the electrode relay switch can be turned on,
Make the common side polarity switch when turned off. Multiplexer 13 uses a three-pole relay,
Connect the common side to the switching device 12, and connect the switching side to A and B, C and D, so that when the electromagnetic relay switch is turned on and off, the current supply destination is A and C1 or B.
and D. Both the switching device 12 and the drive section of the multiplexer 13 are powered by a drive power supply 69.
Connections are made with photocouplers 65, 66, 67, and 68, and the photocouplers are controlled by the computer 1 via the GP-IO interface 9. A flowchart of the actual operation of determining this potential difference jI is shown in FIG. First, reset each device. In this state, both switching device 12 and multiplexer 13 are OFF. In this state, the current supplied from the DC power supply 10.11 is supplied between the A and C terminals. 2, 3, 4,
After measuring the potential difference of 5゜8.9, 10, 1lch, next turn on the switching device 12 to switch the polarity of the current, and then measure the potential difference of 2, 3, 4, 5, 8, 9゜10.1lch again.
Measure the potential difference between Next, the switching device 12 is turned on, the multiplexer 13 for switching the current supply destination is turned on, and current is supplied from the terminals B and D.
, 6, 7° After measuring the potential difference of 12 channels, the switching device 12 is turned on to switch the polarity of the current,
Measure the potential difference of channels 1, 6, 7, and 12 again.

最後にスイッチング装置１２をオフにし、電流供給先切
り換え用のマルチプレクサ１３をオフにしてリセットす
る。Finally, the switching device 12 is turned off, and the multiplexer 13 for switching the current supply destination is turned off and reset.

第１９図には別の測定方法のフローチャートを示す。基
本的には第１３図と同じである。ワーク切れセンサ５９
により、検査される管継手が供給されてパーツフィーダ
５８の先端にあれば検査し、ない場合には検査装置を停
止するが、停止時間が長い場合には、再度、ウオームア
ツプを行うことが必要である。そのため、停止時間がＴ
１よりも長くなった場合には、例えば、運転開始時の試
運転回数が十回よりも少ない二回だけウオームアツプを
行って、検査に備えるものとする。停止時間がＴ、より
も短かければ、ワークがパーツフィーダ５８の先端に供
給された時点で検査を開始する。FIG. 19 shows a flowchart of another measurement method. It is basically the same as FIG. 13. Workpiece out sensor 59
If the pipe fitting to be inspected is supplied and is at the tip of the parts feeder 58, it is inspected, and if it is not, the inspection device is stopped, but if the stopping time is long, it is necessary to warm up again. It is. Therefore, the stop time is T
If it is longer than 1, for example, the number of test runs at the start of operation is less than 10, and warm-up is performed only twice to prepare for inspection. If the stop time is shorter than T, the inspection is started when the workpiece is fed to the tip of the parts feeder 58.

そして、電位差分布を測定した時に、測定された電位差
分布をチエツクして、測定値に異常がないかどうかを確
認する。異常があった場合には、再度測定ヘット７．８
を管継手に押し付け直して電位差分布を測定する。前述
したように、管継手表面の孔や突起物や段差などにより
■１定ヘットの端子が正常に管継手の端面に接触できな
くて、測定異常を起こす訳であるが、測定異常を生じた
場合、管継手が異常であるのか、接触不良であるのかが
区別ができないので再測定する。このとき測定ヘッド７
．８は、−旦、管継手端面から離して、改めて押し付け
直してから電位差分布を測定する。Then, when the potential difference distribution is measured, the measured potential difference distribution is checked to see if there is any abnormality in the measured value. If there is any abnormality, measure the head 7.8 again.
Press it again onto the pipe joint and measure the potential difference distribution. As mentioned above, due to holes, protrusions, steps, etc. on the surface of the pipe fitting, the terminal of the constant head cannot contact the end face of the pipe fitting properly, causing a measurement error. In this case, it is impossible to tell whether the pipe fitting is abnormal or there is a poor connection, so remeasure it. At this time, the measuring head 7
．． In step 8, once removed from the end face of the pipe joint and pressed again, the potential difference distribution is measured.

ただし、測定異常がｍｏ回続いた場合には、上記のよう
に欠陥があるものとして、測定異常品と判別して排除す
るものとする。このとき測定異常であることを欠陥継手
排出部で確認するため、Ａ＝１とおく。測定異常がｍｏ
回続いた場合を含めて測定が終了すると、コンベア５２
を駆動して、測定された管継手を管継手排出部へ移動さ
せる。ここで欠陥があると判定された場合、及び、測定
異常品と判別された場合には欠陥継手排出用シリンダ２
３を駆動して、管継手をコンベア上の試料台５５から突
き落して排出用シュート６３に入れる。However, if the measurement abnormality continues mo times, it is assumed that there is a defect as described above, and the product is determined to be a measurement abnormal product and rejected. At this time, in order to confirm that the measurement is abnormal using the defective joint discharge section, A=1 is set. Measurement abnormality is mo
When the measurement is completed, even if the measurement is repeated several times, the conveyor 52
to move the measured pipe fitting to the pipe fitting discharge section. If it is determined that there is a defect here, or if it is determined that the product is abnormal in measurement, the defective joint discharge cylinder 2
3 to push the pipe fitting down from the sample stage 55 on the conveyor and into the discharge chute 63.

このとき欠陥品と測定異常品の個数Ｋを積算して欠陥品
の頻度度数を記録する。この一連の作業を繰返すことに
より管継手の欠陥検査を自動的に行う。At this time, the number K of defective products and abnormally measured products is added up to record the frequency of defective products. By repeating this series of operations, defects in pipe joints are automatically inspected.

第２０図には別の測定方法のフローチャートを示す。基
本的には第１９図と同じであり、その電位差測定と判定
方法の部分について詳細に記したものである。測定開始
に当たり、全ての機器をリセットしてから電位差分布を
測定する。電流の極性を切り換え、給電端子を切り換え
て電位差分布を測定すると、電位差振幅ｖＩ　を計算す
る。次に、４１１１定異常の確認を行う。但し、測定異
常と判定すべき項目として、前述したような管継手が異
常品である他に直流電源が故障して電流が流れなくなっ
たとか、電流供給用の配線が断線した場合にはｍ　Ｑが
形成されないので、すべてのＶ、は殆どＯμ■となる。FIG. 20 shows a flowchart of another measurement method. This is basically the same as FIG. 19, and the details of the potential difference measurement and determination method are described here. Before starting measurement, reset all equipment and then measure the potential difference distribution. When the polarity of the current is switched, the power supply terminal is switched, and the potential difference distribution is measured, the potential difference amplitude vI is calculated. Next, a 4111 constant abnormality is confirmed. However, items that should be judged as measurement abnormalities include, in addition to the above-mentioned abnormal pipe fittings, the DC power supply malfunctions and current no longer flows, or the current supply wiring is disconnected. is not formed, so all V becomes almost Oμ■.

通常４Ａ８度の電流を流すとＶｌは１００〜２００μＶ
であるので、例えば、Ｖｎが５μＶ以下であれば、その
ようなことが起きたと判断される。逆に異常品の場合や
接触不良の場合には、ＶｒはＶ、が数百μＶ以上の大き
な値となるので、Ｖｎ＜ｖｔ＜ｖ、でなければ、ｍ＝ｍ
＋１と設定した上で、再度電位差分布を測定し、再び、
測定異常を判定する。再度、■、〈ｖｎであった場合に
は、電流供給系統の異常と判定される。その場合でもす
べて■、くｖｎであった場合には直流電源の故障と判定
され１部分的にｖｌ〈ｖｎであった場合には電流供給用
の配線が断線したとき判定して、それぞれの警報を出す
ものとする。そして、前述したように、測定異常を繰返
してｍ≧ｍｏとなれば測定異常であることを確認するた
めＡを１と設定し、さらに、測定異常品の個数Ｍを積算
する。電位差分布が測定異常と判定されなかった場合に
は、初めに最大電位差Ｖ　ｍ　ａ　ｘを、次に、最小電
位差Ｖ　ＩＩ　Ｉ　ｎを判定する。そして、最大電位差
Ｖ　ｍ　ａ　Ｘと最小電位差Ｖ　＊　ｉ　ｎの比ＩＩ　
ａ　Ｘ　／　Ｖ　ＩＩ　ｌ　ｎを計算し、それがＶ−ａ
ｘ／Ｖ−ｉ□＞Ｖｖ、例えば、Ｖｖ＝１．２５であれば
偏心大として異常品と判定してここでもＡ＝１と設定し
、さらに、測定異常品の個数りを積算する。Ｖ−ａｘ／
Ｖｍｔｎ＜Ｖｖの場合には電位差比■ｌ／ｖｏを計算し
て、Ｖ　ｔ　／　Ｖ　ｏ　＞　Ｖ　ｕ　、例えば、Ｖｕ
　＝ｌ、１０であれば欠陥品と判定してここでもＡ＝１
と設定し、さらに、欠陥品の個数Ｋを積算する。Ｖｌ／
Ｖｏ＜Ｖｕの場合には欠陥はないので、無欠陥品個数Ｊ
を精算する。そして最後にＣＲＴ画面に測定結果、例え
ば、電位差分布ｖｌ。Normally, when a current of 4A and 8 degrees flows, Vl is 100 to 200 μV.
Therefore, for example, if Vn is 5 μV or less, it is determined that such an event has occurred. On the other hand, in the case of an abnormal product or poor contact, Vr will be a large value of several hundred μV or more, so unless Vn<vt<v, m=m
After setting it to +1, measure the potential difference distribution again, and again,
Determine measurement abnormality. Again, if ■, <vn, it is determined that there is an abnormality in the current supply system. Even in that case, if all of the voltages are ■, or vn, it is determined that there is a failure in the DC power supply, and if the voltage is partially vl<vn, it is determined that the current supply wiring is disconnected, and each alarm is activated. shall be issued. Then, as described above, if the measurement abnormality is repeated and m≧mo, A is set to 1 to confirm that there is a measurement abnormality, and the number M of abnormally measured products is added up. If the potential difference distribution is not determined to be abnormal in measurement, first the maximum potential difference Vmax is determined, and then the minimum potential difference VIIIn is determined. Then, the ratio II of the maximum potential difference V m a X and the minimum potential difference V * i n
Calculate a
If x/V-i□>Vv, for example, Vv=1.25, it is determined that the eccentricity is large and the product is abnormal, and A=1 is set here as well, and the number of abnormal products to be measured is added up. V-ax/
When Vmtn<Vv, calculate the potential difference ratio ■l/vo and find that Vt/Vo>Vu, for example, Vu
= l, if it is 10, it is determined that it is a defective product, and A = 1 here as well.
Then, the number K of defective products is added up. Vl/
If Vo<Vu, there is no defect, so the number of defect-free products J
settle the payment. Finally, the measurement results are displayed on the CRT screen, for example, the potential difference distribution vl.

最大電位差Ｖ　ｍ　ａ　Ｘ、最小電位差Ｖ　ｍ　１　ｎ
、最大電位差と最小電位差の比Ｖｍａｘ／　Ｖｍｔｎ、
電位差比分布Ｖ　Ｉ／　Ｖ　ｏ、測定個数■、測定異常
品個数Ｍ、異常品個数し、欠陥品個数Ｋ、無欠陥品個数
Ｊ等を表示する。Maximum potential difference V m a X, minimum potential difference V m 1 n
, ratio of maximum potential difference to minimum potential difference Vmax/Vmtn,
The potential difference ratio distribution V I/V o, the number of measured items (■), the number of abnormal items measured M, the number of abnormal items, the number of defective items K, the number of non-defective items J, etc. are displayed.

第２１図には別の実施例を示す。これは第１図に示した
管継手検査装置において、欠陥品排出部を三組設けるこ
とにより、種々の欠陥品を分類して排出するためである
。即ち、第１９図の電位差測定及び電位差分布からの欠
陥品の判定方法のフローチャートで説明したように、測
定された管継手は測定異常品、異常品、欠陥品、無欠陥
品の四種類に分類ぎれる。そこで、第２２図に示したよ
うに、測定異常を繰り返してｍ≧ｍｏ　となれば測定異
常であることを確認するためＡ＝１と設定する。次に、
最大電位差Ｖ　ｍ　ａ　ｘと最／ＪＳ電位差ｖ０゜の比
Ｖｍａｘ／Ｖ＊ｒｎがｖ、ａＸ／ｖ、ｉｎ＞ｖｖであれ
ば異常品と判定してここではＢ＝１と設定する。また、
電位差比Ｖ　ｌ／　Ｖ　ｏを計算して、ｖ１／■ｏ＞Ｖ
ｕであれば欠陥品と判定してここではＣを１と設定する
。測定を終えた管継手が順次搬送されるとき、Ａが１で
あれば、測定異常品排出シリンダ７１を駆動して排出シ
ュート７２に載せて測定異常品収納箱に入れ、Ｂ−４で
あれば、異常品排出シリンダ７３を駆動して排出シュー
ト７４に載せて異常品収納箱に入れ、Ｃが１であれば、
欠陥品排出シリンダ７５を駆動して排出シュート７６に
載せて欠陥品収納箱に入れ、無欠陥品はそのような排出
シリンダを駆動することなくコンベア５２に載せたまま
、次の工程に送り出すものとする。FIG. 21 shows another embodiment. This is because the pipe joint inspection apparatus shown in FIG. 1 is provided with three sets of defective product discharge sections to classify and discharge various defective products. That is, as explained in the flowchart of the method for determining defective products from potential difference measurement and potential difference distribution in FIG. 19, the measured pipe fittings are classified into four types: abnormal measurements, abnormal products, defective products, and non-defective products. I can't stand it. Therefore, as shown in FIG. 22, if the measurement abnormality is repeated and m≧mo, A=1 is set to confirm that the measurement is abnormal. next,
If the ratio Vmax/V*rn of the maximum potential difference Vmax and the maximum /JS potential difference v0° is v, aX/v, in>vv, it is determined that it is an abnormal product, and B=1 is set here. Also,
Calculate the potential difference ratio V l/V o and find v1/■o>V
If it is u, it is determined that the product is defective, and C is set to 1 here. When the pipe fittings that have been measured are transported one by one, if A is 1, the abnormal measurement product discharge cylinder 71 is driven and the abnormal measurement product is placed on the discharge chute 72 and placed in the measurement abnormal product storage box, and if B-4 , the abnormal product discharge cylinder 73 is driven and the abnormal product is placed on the discharge chute 74 and placed in the abnormal product storage box, and if C is 1,
The defective product discharge cylinder 75 is driven and the defective product is placed on the discharge chute 76 and placed in the defective product storage box, and the non-defective products are sent to the next process while being placed on the conveyor 52 without driving such a discharge cylinder. do.

第２３図から第２５図には別の実施例を示す。Another embodiment is shown in FIGS. 23 to 25.

第２３図は管継手検査装置の平面図である。これは第１
図の装置で、パーツフィーダ５８からの管継手の供給方
法を変えたものである。すなわち、第１図、または、第
２図ではパーツフィーダ５８をコンベア５２の横に置い
て管継手挿入シリンダ１７により管継手をコンベア上の
試料台に載せていたものを、第２３図ではパーツフィー
ダ５８をコンベア５２の直上に持って来るようにしたも
のである。但し、この場合には、第２４図に示したよう
に、コンベア５２の横方向には管継手ガイド７７を設け
ると共に、第２５図に示したように、パーツフィーダ５
８の先端には管継手押さえシリンダ７８を配置して、管
継手が落下しないようにする機構を設ける。FIG. 23 is a plan view of the pipe joint inspection device. This is the first
This is the device shown in the figure, with a different method of supplying pipe fittings from the parts feeder 58. That is, in FIG. 1 or 2, the parts feeder 58 is placed next to the conveyor 52 and the pipe fitting is placed on the sample stage on the conveyor by the pipe fitting insertion cylinder 17, whereas in FIG. 58 is brought directly above the conveyor 52. However, in this case, as shown in FIG. 24, a pipe joint guide 77 is provided in the lateral direction of the conveyor 52, and as shown in FIG.
A pipe joint holding cylinder 78 is disposed at the tip of the pipe joint 8 to provide a mechanism to prevent the pipe joint from falling.

第２６図には別の実施例を示す。これは複数の管継手挿
入部と測定部を配置することにより複数個の管継手を同
時に検査できるようにして、検査時間の短縮を図るもの
である。第２６図の場合には四個の管１継手挿入部と四
組の測定部を配置してある。但し、欠陥品が発生する頻
度は低いので、欠陥品排出部は一組だけ設けである。FIG. 26 shows another embodiment. This is intended to shorten the inspection time by arranging a plurality of pipe fitting insertion sections and measuring sections so that a plurality of pipe fittings can be inspected simultaneously. In the case of FIG. 26, four pipe 1 joint insertion sections and four sets of measurement sections are arranged. However, since the frequency of occurrence of defective products is low, only one set of defective product discharge sections is provided.

第２７図は別の実施例を示す。第１図から第３図に示し
たような管継手検査装置において、ベルトコンベア５２
に載せる試料台５５の形状をエルボ型継手を載せられる
ような形状とし、第２７図に示したように測定部におい
て測定ヘット８用シリンダ２１を水平方向に配置し、測
定ヘッド７用シリンダ１９を垂直方向に配置することに
より、エルボ型継手の両端面表面の電位差分布を測定可
能とした。FIG. 27 shows another embodiment. In the pipe joint inspection apparatus shown in FIGS. 1 to 3, the belt conveyor 52
The shape of the sample stage 55 to be placed on the sample table is such that an elbow joint can be placed thereon, and the cylinder 21 for the measuring head 8 is arranged horizontally in the measuring section as shown in FIG. By arranging it in the vertical direction, it was possible to measure the potential difference distribution on both end surfaces of the elbow joint.

第２８図には別の実施例を示す。第１図から第３図に示
したような管継手検査装置において、測定部において測
定ヘッド７用シリンダ１９と測定ヘッド８用シリンダ２
１を水平方向に一直線上に配置し、いま一つの測定ヘッ
ド９用シリンダ８０を垂直方向に配置することにより、
ティー型継手の三つの端面の電位差分布を測定可能とし
た。FIG. 28 shows another embodiment. In the pipe fitting inspection apparatus shown in FIGS. 1 to 3, a cylinder 19 for the measuring head 7 and a cylinder 2 for the measuring head 8 are installed in the measuring section.
1 in a straight line in the horizontal direction, and the cylinder 80 for the other measuring head 9 in the vertical direction.
It has become possible to measure the potential difference distribution on the three end faces of a tee-shaped joint.

〔発明の効果〕〔Effect of the invention〕

本発明によれば欠陥品、異常品等の弁別を製造ラインに
おいてインラインで精度良く判定することができ、管継
手の品質管理が向上する。According to the present invention, defective products, abnormal products, etc. can be accurately determined in-line in a manufacturing line, and quality control of pipe fittings is improved.

【図面の簡単な説明】[Brief explanation of the drawing]

第１図は本発明の一実施例の管継手検査装置の平面図、
第２図は管継手挿入部の正面図、第３図は電位差分布測
定部の正面図、第４図は欠陥品排出部の正面図、第５図
は管継手検査装置のシステム系統図、第６図は測定ヘッ
ドの構造図、第７図は欠陥のない管継手の端面における
電位差分布図、第８図は欠陥をもつ管継手の端面におけ
る電位差分布図、第９図は電位差比と欠陥深さの関係を
示す図、第１０図は欠陥はないが偏心のある管継手の端
面における電位差分布図、第１１図と第１２図は隣りの
端子間の電位差の平均を基準電位差として求めた電位差
比分布図、第１３図は管継手検査装置の検査のフローチ
ャート、第１４図は測定ヘッドにおける各端子の接続図
、第１５図は電位差分布測定のフローチャート、第１６
図は電位差測定系統の詳細な配線図、第１７図は電流供
給系統の配線図、第１８図は電位差分布測定の具体的な
フローチャート、第１９図は管継手検査装置の検査のフ
ローチャート、第２０図は電位差測定及び判定方法のフ
ローチャート、第２１図は管継手検査装置の平面図、第
２２図は電位差測定及び判定方法のフローチャー１・、
第２３図は管継手検査装置の平面図、第２４図は管、継
手挿入部の正面図、第２５図は管継手挿入部の側面図、
第２６図は管継手検査装置の平面図、第２７図はエルボ
型管継手の検査装置の平面図、第２８図はティー型管継
手の検査装置の平面図である。 １−・コンピュータ、２・ＣＲＴ、３・・プリンタ、４
　・ＧＰ−ＩＢインターフェース、５・・・微小電位差
計、６・・マルチプレクサ。 第２図 第３図 第４図 第５図 管継手検査装置のシステム系統図 第６図 第７図 干　ν　〉λ１し岐（ｃｌ） 第８図 干ｆンネ１し歓（ｔＪｌ） 第９図 第１０因 仏〉ネｒｔ＃　　（ｄ） 第１１− も→才ｒＬｆｉ　（ｃｌ） 第１２図 →マ〉ネｔｔＬｔめ 可／３図 第１４図 第１乙図 粥１７図 スイッチング　マルチプレクサ 第１Ｐ図 第１９Ｉ！ｌ 用２θ図 Ｑ（二つ 庸２１図 第２２図 第２３図 第２夕図 第２６ｆｉ 第２７昆 １２８図FIG. 1 is a plan view of a pipe joint inspection device according to an embodiment of the present invention;
Fig. 2 is a front view of the pipe fitting insertion section, Fig. 3 is a front view of the potential difference distribution measuring section, Fig. 4 is a front view of the defective product discharge section, Fig. 5 is a system diagram of the pipe fitting inspection device, Figure 6 is a structural diagram of the measurement head, Figure 7 is a potential difference distribution diagram at the end face of a pipe joint without defects, Figure 8 is a potential difference distribution diagram at the end face of a pipe joint with defects, and Figure 9 is a potential difference ratio and defect depth. Figure 10 is a potential difference distribution diagram at the end face of a pipe joint with no defects but eccentricity, and Figures 11 and 12 are potential differences determined by using the average of the potential differences between adjacent terminals as a reference potential difference. Ratio distribution diagram, Fig. 13 is a flowchart of the inspection of the pipe joint inspection device, Fig. 14 is a connection diagram of each terminal in the measurement head, Fig. 15 is a flowchart of potential difference distribution measurement, Fig. 16
The figure shows a detailed wiring diagram of the potential difference measurement system, Figure 17 is a wiring diagram of the current supply system, Figure 18 is a specific flowchart of potential difference distribution measurement, Figure 19 is a flowchart of the inspection of the pipe joint inspection device, and Figure 20 is a detailed wiring diagram of the potential difference measurement system. The figure is a flowchart of the potential difference measurement and determination method, FIG. 21 is a plan view of the pipe joint inspection device, and FIG. 22 is a flowchart of the potential difference measurement and determination method.
Fig. 23 is a plan view of the pipe fitting inspection device, Fig. 24 is a front view of the pipe and fitting insertion part, Fig. 25 is a side view of the pipe fitting insertion part,
FIG. 26 is a plan view of a pipe joint inspection device, FIG. 27 is a plan view of an elbow type pipe joint inspection device, and FIG. 28 is a plan view of a tee type pipe joint inspection device. 1- Computer, 2 CRT, 3 Printer, 4
・GP-IB interface, 5...Micropotentiometer, 6...Multiplexer. Fig. 2 Fig. 3 Fig. 4 Fig. 5 System diagram of pipe joint inspection equipment Fig. 6 Fig. 7 10th cause Buddha〉nert # (d) 11th - Mo → Sai rLfi (cl) Figure 12 → Manet Lt Me possible/Figure 3 Figure 14 Figure 1 Figure Otsu Figure 17 Figure Switching Multiplexer Figure 1P Figure 19I! 2θ diagram for l

Claims (1)

【特許請求の範囲】 １、被測定物に直流電流を印加して電場を形成し、測定
された電位差から欠陥の深さを検出する装置において、 前記被測定物である管継手を供給するパーツフィーダと
、前記管継手を載せる試料台を多数取付けたコンベアと
、前記パーツフィーダから供給された前記管継手を前記
コンベア上の前記試料台に挿入するための空気シリンダ
と、前記管継手を前記試料台上で位置決めするためのス
トッパと、前記コンベアを駆動させるためのモータと、
前記モータを駆動制御するモータ駆動装置と、直流電流
の供給と電位差の測定を兼用する多数の端子をもつ測定
ヘッドをそれぞれの軸端に取付けた二個の空気シリンダ
と、欠陥有りと判定された前記管継手を前記コンベアの
試料台から排除するための前記空気シリンダと排出用シ
ュートと、前記管継手が前記パーツフィーダにあること
を検出するためのワーク切れセンサと、前記コンベア上
の試料台の位置を検出するためのワーク通過センサと、
前記各空気シリンダを駆動するための圧縮空気源と電磁
弁と、電位差分布測定のために二個の測定ヘッドの多数
の端子を切り換えるためのマルチプレクサと、電位差測
定のための微小電位差計と、直流供給用の二台の直流電
源と、直流電流の極性を切り換えるためのスイッチング
装置と、前記直流電流を供給する端子を切り換えるため
のマルチプレクサと、前記各機器を制御し、測定された
電位差分布から欠陥の有無等を判定するためのコンピュ
ータと、前記各機器と前記コンピュータを接続するため
のインターフェースと、判定された結果を出力するため
のＣＲＴとプリンタとを備えたことを特徴とする管継手
欠陥検査装置。 ２、特許請求の範囲第１項において、 前記試料台を前記コンベアの上に等間隔で取付け、管継
手挿入用シリンダと測定ヘッド駆動用シリンダと欠陥管
継手排出用シリンダを前記コンベアの前記試料台の間隔
と同じ間隔で配置したことを特徴とする管継手欠陥検査
装置。 ３、特許請求の範囲第１項において、 円筒形状の測定ヘッドに同心円状に直流電流供給と電位
差測定を兼用した端子を等間隔で、対称形に少なくとも
八個以上の四の倍数の複数個配置し、その端子のピッチ
円直径が被測定物である管継手の内外径の平均と内径と
の中間となるようにしたことを特徴とする管継手欠陥検
査装置。 ４、特許請求の範囲第１項または第２項記載において、 １８０度離れて向い合う二個の端子から直流電流を印加
してその両隣にある端子間を除く端子間の電位差を測定
する手段と、前記１８０度離れて向い合う二個の端子か
らそれぞれ９０度離れた二個の端子から直流電流を印加
する手段と、前記電位差の測定のときに測定した端子間
を除く端子間の電位差を測定する手段と、前記管継手の
両端面の全円周上の電位差分布を求め、それらの比較演
算から欠陥深さを検出する手段とからなることを特徴と
する管継手欠陥検査装置。 ５、特許請求の範囲第１項、第２項または第３項におい
て、 測定された電位差分布より、各端子間の電位差について
その端子間の両隣りの端子間の電位差の平均を基準電位
差として電位差比を求める手段と、その電位差比により
欠陥の大きさを判定する手段とからなることを特徴とす
る管継手欠陥検査装置。 ６、特許請求の範囲第１項、第２項または第３項におい
て、 測定された電位差分布において最大電位差と最小電位差
を求める手段と、その比がある一定値よりも大きい場合
には不良品として判定する手段とからなることを特徴と
する管継手欠陥検査装置。 ７、特許請求の範囲第１項、第２項または第３項におい
て、 電位差測定において端子の接触不良や前記被測定物であ
る前記管継手の不良により測定された電位差がある一定
値よりも大きいか、ある一定値よりも小さい場合には、
測定ヘッドを押し付け直して再度測定する手段と、測定
された電位差がある範囲内に収まるまで繰返し、その繰
返し数がある一定値を超えた場合には測定異常品と判定
する手段とからなることを特徴とする管継手欠陥検査装
置。 ８、特許請求の範囲第１項において、 欠陥ありと判定された前記管継手を前記コンベアの前記
試料台から排除するための前記空気シリンダと共に、不
良品と判定された前記管継手を前記コンベアの前記試料
台から排除するための前記空気シリンダと、測定異常品
と判定された前記管継手を前記コンベアの前記試料台か
ら排除するための前記空気シリンダと、排出用シュート
を備えたことを特徴とする管継手欠陥検査装置。 ９、特許請求の範囲第１項において、 前記パーツフィーダを前記コンベアの直上に設け、かつ
、前記パーツフィーダの先端部に被測定試料である前記
管継手を前記空気シリンダにより一個ずつ前記コンベア
上の前記試料台に送り込めるようにしたことを特徴とす
る管継手欠陥検査装置。 １０、特許請求の範囲第１項において、 一個の前記パーツフィーダから複数個のパイプに分岐さ
せた前記管継手の挿入部を設け、それぞれの前記管継手
の前記挿入部の直下に前記コンベア上の前記試料台に挿
入するための前記空気シリンダを複数個設け、直流電流
の供給と電位差の測定を兼用する多数の端子を設けた測
定ヘッドをそれぞれの軸端に取付けた二個の前記空気シ
リンダを一組とする測定部を複数組設け、欠陥有りと判
定された前記管継手を前記コンベアの前記試料台から排
除するための前記空気シリンダと排出用シュートを少な
くとも一組設けたことを特徴とする管継手欠陥検査装置
。 １１、特許請求の範囲第１項において、 前記コンベアに取付けた多数の前記管継手を載せる前記
試料台の形状を鞍型の両端開放型としてユニオン継手を
載せられるようなものとし、直流電流の供給と電位差の
測定を兼用する多数の端子をもつ測定ヘッドをそれぞれ
の軸端に取付けた二個の前記空気シリンダを前記管継手
を載せる前記試料台をはさんで一直線状に配置したこと
を特徴とする管継手欠陥検査装置。 １２、特許請求の範囲第１項において、 前記コンベアに取付けた多数の前記管継手を載せる前記
試料台の形状をエルボ型継手を載せられるようなものと
し、前記エルボ型継手の一方の軸端を水平に、もう一方
の軸端を垂直方向とし、直流電流の供給と電位差の測定
を兼用する多数の端子をもつ測定ヘッドをそれぞれの軸
端に取付けた二個の前記空気シリンダを前記管継手を載
せる前記試料台をはさんで一方の軸を水平に、もう一方
の軸を垂直にして測定ヘッドがエルボ型継手の両端に押
し付けられるように配置したことを特徴とする管継手欠
陥検査装置。 １３、特許請求の範囲第１項において、 前記コンベアに取付けた多数の前記管継手を載せる前記
試料台の形状を鞍型の両端開放型としてティー型継手を
載せられるようなものとし、前記ティー型継手の直行す
る方の軸を水平に、分岐する方の軸を試直方向とし、直
流電流の供給と電位差の測定を兼用する多数の端子をも
つ測定ヘッドをそれぞれの軸端に取付けた三個の前記空
気シリンダのうち、二個の前記空気シリンダを前記管継
手を載せる前記試料台をはさんで水平に一直線状に配置
し、一個の前記空気シリンダを垂直方向に配置して、三
個の測定ヘッドがティー型継手の三個の開口端に押し付
けられるように配置したことを特徴とする管継手欠陥検
査装置。[Claims] 1. In an apparatus that applies a direct current to an object to be measured to form an electric field and detects the depth of a defect from the measured potential difference, a part that supplies the pipe joint that is the object to be measured. a feeder, a conveyor equipped with a large number of sample stands on which the pipe fittings are mounted; an air cylinder for inserting the pipe fittings supplied from the parts feeder into the sample stands on the conveyor; a stopper for positioning on a table; a motor for driving the conveyor;
It was determined that the motor drive device that drives and controls the motor, and the two air cylinders each equipped with a measuring head with a large number of terminals that serves both to supply direct current and to measure potential differences, were defective. the air cylinder and discharge chute for removing the pipe fitting from the sample stand on the conveyor; a workpiece outage sensor for detecting that the pipe fitting is in the parts feeder; A workpiece passing sensor for detecting the position,
A compressed air source and a solenoid valve for driving each of the air cylinders, a multiplexer for switching a number of terminals of the two measuring heads for measuring the potential difference distribution, a minute potentiometer for measuring the potential difference, and a direct current Two DC power supplies for supply, a switching device for switching the polarity of the DC current, a multiplexer for switching the terminal for supplying the DC current, and controlling each of the above devices, and detecting defects from the measured potential difference distribution. A pipe joint defect inspection comprising: a computer for determining the presence or absence of a defect, an interface for connecting each of the devices and the computer, and a CRT and a printer for outputting the determined results. Device. 2. In claim 1, the sample stand is mounted on the conveyor at equal intervals, and a cylinder for inserting a pipe fitting, a cylinder for driving a measurement head, and a cylinder for discharging a defective pipe fitting are mounted on the sample stand of the conveyor. A pipe joint defect inspection device characterized in that the pipe fittings are arranged at the same intervals as the intervals between the pipe joints. 3. In claim 1, a plurality of terminals serving both DC current supply and potential difference measurement are arranged concentrically on a cylindrical measuring head at equal intervals and symmetrically, at least eight or more terminals in multiples of four. A pipe fitting defect inspection device characterized in that the pitch circle diameter of the terminal is set between the average inner and outer diameters and the inner diameter of the pipe fitting as the object to be measured. 4. In claim 1 or 2, means for applying a direct current from two terminals facing each other 180 degrees apart and measuring the potential difference between the terminals excluding the terminals on both sides thereof. , means for applying a direct current from two terminals separated by 90 degrees from the two terminals facing each other at a distance of 180 degrees, and measuring a potential difference between terminals other than the terminals measured at the time of measuring the potential difference. A pipe joint defect inspection device comprising: a means for determining a potential difference distribution over the entire circumference of both end faces of the pipe joint, and a means for detecting a defect depth from a comparison calculation thereof. 5. In claim 1, 2, or 3, the potential difference between each terminal is determined from the measured potential difference distribution by using the average of the potential differences between the terminals on both sides as a reference potential difference. A pipe joint defect inspection device comprising means for determining a ratio and means for determining the size of a defect based on the potential difference ratio. 6. Claims 1, 2, or 3 provide means for determining the maximum potential difference and the minimum potential difference in the measured potential difference distribution, and if the ratio is larger than a certain value, the product is considered defective. 1. A pipe joint defect inspection device comprising: determining means. 7. In claim 1, 2, or 3, in potential difference measurement, the potential difference measured due to a poor contact of a terminal or a defect in the pipe joint that is the object to be measured is greater than a certain value. or if it is smaller than a certain value,
It consists of a means to press the measurement head again and take the measurement again, and a means to repeat the measurement until the measured potential difference falls within a certain range, and if the number of repetitions exceeds a certain value, it is determined that the product is abnormal in measurement. Features: Pipe joint defect inspection equipment. 8. In claim 1, together with the air cylinder for removing the pipe fitting determined to be defective from the sample stage of the conveyor, the pipe fitting determined to be defective is removed from the conveyor. It is characterized by comprising: the air cylinder for removing from the sample table; the air cylinder for removing the pipe fitting determined to be a measurement abnormal product from the sample table of the conveyor; and a discharge chute. Pipe joint defect inspection equipment. 9. In claim 1, the parts feeder is provided directly above the conveyor, and the pipe fittings, which are samples to be measured, are placed one by one on the conveyor at the tip of the parts feeder using the air cylinder. A pipe joint defect inspection device characterized in that it can be fed into the sample stage. 10. In claim 1, an insertion portion of the pipe joint is provided that branches from one parts feeder into a plurality of pipes, and the insertion portion of the pipe joint is provided directly below the insertion portion of each pipe joint on the conveyor. A plurality of the air cylinders are provided to be inserted into the sample stage, and two air cylinders each have a measuring head provided with a large number of terminals for both supplying direct current and measuring potential difference attached to the shaft end of each cylinder. A plurality of sets of measuring units are provided, and at least one set of the air cylinder and discharge chute for removing the pipe joint determined to be defective from the sample stage of the conveyor is provided. Pipe joint defect inspection device. 11. In claim 1, the shape of the sample stage on which a large number of the pipe joints attached to the conveyor is placed is a saddle-shaped shape with both ends open so that a union joint can be placed thereon, and a direct current is supplied. The two air cylinders, each having a measuring head having a large number of terminals for measuring the potential difference, are arranged in a straight line across the sample stage on which the pipe joint is placed. Pipe joint defect inspection equipment. 12. In claim 1, the shape of the sample stage on which a large number of the pipe joints attached to the conveyor is placed is such that an elbow type joint can be placed thereon, and one shaft end of the elbow type joint is The two air cylinders are connected to the pipe joint horizontally, with the other shaft end facing vertically, and measuring heads with multiple terminals for both supplying DC current and measuring potential differences are attached to each shaft end. A pipe joint defect inspection device characterized in that the measuring head is arranged so as to be pressed against both ends of an elbow joint with one axis horizontal and the other vertical across the sample stage on which it is placed. 13. In claim 1, the shape of the sample stage on which a large number of the pipe joints attached to the conveyor is mounted is a saddle-shaped shape with both ends open so that a tee-shaped joint can be mounted, The orthogonal axis of the joint is horizontal, the branching axis is in the test direction, and a measuring head with multiple terminals that serves both for supplying DC current and measuring potential difference is attached to the end of each of the three shafts. Of the air cylinders, two of the air cylinders are arranged horizontally in a straight line across the sample stage on which the pipe fitting is placed, one of the air cylinders is arranged vertically, and three A pipe joint defect inspection device characterized in that a measuring head is arranged so as to be pressed against three open ends of a tee-shaped joint.