JPS6113968Y2 - - Google Patents

Description

【考案の詳細な説明】 本考案は管状体の超音波探傷装置、とくに探触
子回転型超音波探傷装置に関する。[Detailed Description of the Invention] The present invention relates to an ultrasonic flaw detection device for tubular bodies, and particularly to a probe rotation type ultrasonic flaw detection device.

小径鋼管等の管状体を探傷する場合には通常、
被検査管の周りに探触子を回転させて被検査管を
直進させながら被検査管の表面をスパイラル状に
走査して探傷する回転型超音波探傷装置が常用さ
れている。その一例は第１図に示すように被検査
管１が内部を矢印Ｄ方向に通過する固定管２を具
え、この固定管２の外周に軸受３を介して管状の
回転体４が回転自在に嵌着し、その適宜の位置
（図面では被検査管の入口側）に設けたプーリ５
を介して外部の駆動源によつて回転される。この
回転体４の被検査管出口側端部には、周方向に被
検査管１へ向う探触子６を１個または複数個具
え、更に該探触子６の前面に超音波の伝達媒体で
ある水を供給する給水路７を具えて探触子保持体
が装着されている。該給水路７は回転体４、シー
ル８および固定管２を経由して外部の給水管９に
連接されている。このような従来の構造では、探
触子保持体を回転体４の端部に設け、探触子に外
部から給水する機構と探触子と外部との電気的接
続回路とを回転体４に組み込んであるので、回転
体４の回転速度が通常1500回／分程度の回転数で
ある場合には問題を生じいが、この通常回転数を
はるかに上回る高速回転、例えば3000回／分程度
の回転数になると、探触子保持体の一方の端が開
放端となつているために高速回転に伴い揺動が大
きくなり、この探触子保持体の振れが探傷精度に
与える影響を無視できなくなる。またこのような
給水系において高速回転時に探触子の直下への給
水の安定性を確保するためには、高い水圧をかけ
る必要があるが、そうするとシール８のシール機
能が低下し、水供給が不充分になると共に、軸受
３に水が混入したり、あるいは軸受３の潤滑油が
水に混入する問題を生じる。また軸受に流体軸受
を用いるものもあるが、やはり高速回転時には探
触子に供給する水のシール機能が低下し、探触子
の直下への安定した水の供給が困難となる。その
他に探触子の直下に比較的大きな水室を設け、固
定部を介して大量の水を供給する方法もあるが、
大量の水を使うと被検査管の端部から内部に水が
侵入し、それが擬似欠陥信号となつて探傷不能と
なる。このため管内に水が入らないように管端キ
ヤツプの装着が必要となるが被検査管の一本一本
にキヤツプの着脱を行うことは作業的に大きな負
担になる。さらにまた従来の構造では探触子保持
体の直前，直後に被検査管を支持案内する機構が
ないので、被検査管の自重による撓みのために被
検査管の上側と下側で探触子と被検査管外面との
距離が変り、甚だしいときは被検査管の下側が探
触子保持体の内面に接触するなど、探傷の精度
上、作業上の問題があつた。 When testing tubular bodies such as small diameter steel pipes,
BACKGROUND ART A rotary ultrasonic flaw detection device is commonly used, which detects flaws by rotating a probe around a tube to be inspected and scanning the surface of the tube in a spiral manner while moving the tube to be inspected in a straight line. In one example, as shown in FIG. 1, a tube to be inspected 1 is provided with a fixed tube 2 through which it passes in the direction of arrow D, and a tubular rotating body 4 is rotatably attached to the outer periphery of the fixed tube 2 via a bearing 3. The pulley 5 is fitted and installed at an appropriate position (in the drawing, on the inlet side of the pipe to be inspected).
It is rotated by an external driving source via the . The rotating body 4 is equipped with one or more probes 6 facing toward the tube 1 in the circumferential direction on the outlet side of the tube to be inspected, and an ultrasonic transmission medium is provided in front of the probe 6. The probe holder is equipped with a water supply channel 7 for supplying water. The water supply channel 7 is connected to an external water supply pipe 9 via the rotating body 4, the seal 8, and the fixed pipe 2. In such a conventional structure, a probe holder is provided at the end of the rotating body 4, and a mechanism for supplying water to the probe from the outside and an electrical connection circuit between the probe and the outside are provided on the rotating body 4. Since the rotation speed of the rotating body 4 is usually around 1500 rotations/minute, this will not cause problems, but if the rotation speed is much higher than this normal rotation speed, for example around 3000 rotations/minute, a problem will occur. When the rotation speed increases, the vibration becomes large due to high-speed rotation because one end of the probe holder is open, and the effect of this vibration of the probe holder on flaw detection accuracy can be ignored. It disappears. In addition, in such a water supply system, it is necessary to apply high water pressure in order to ensure the stability of water supply directly below the probe during high-speed rotation, but this reduces the sealing function of the seal 8 and reduces the water supply. If this becomes insufficient, a problem arises in that water gets mixed into the bearing 3 or the lubricating oil of the bearing 3 gets mixed into the water. Some bearings use hydrodynamic bearings, but the sealing function of water supplied to the probe deteriorates during high-speed rotation, making it difficult to stably supply water directly below the probe. Another method is to install a relatively large water chamber directly below the probe and supply a large amount of water through the fixed part.
If a large amount of water is used, water will enter from the end of the pipe to be inspected, causing a false defect signal and making flaw detection impossible. For this reason, it is necessary to attach tube end caps to prevent water from entering the tubes, but attaching and detaching the caps to each tube to be inspected is a heavy workload. Furthermore, in the conventional structure, there is no mechanism to support and guide the tube to be inspected just before and after the probe holder, so the probe is attached to the upper and lower sides of the tube to be inspected due to deflection due to the tube's own weight. The distance between the test tube and the outer surface of the tube to be inspected changes, and in extreme cases, the lower side of the tube to be inspected comes into contact with the inner surface of the probe holder, causing problems in terms of accuracy and work.

本考案は、上述の点に鑑み、高速回転時の探傷
においても秀抜な探傷精度を維持するように、被
検査管の支持機構、探触子保持体の保持機構およ
び給水機構等に高速回転における安定性を付与し
たものであり、その構成は、入口側端部に被検査
管の導入案内具を設けた固定筒状体と、該固定筒
状体の外周に回転自在に設けた回転円筒体と、該
回転円筒体を軸受を介して長手方向に少なくとも
二点で支持する支持機構を有する管状体の探触子
回転型超音波探傷装置において、被検査管の外径
より僅かに大きい内径を有する探触子保持体を前
記回転円筒体の出口側端に着脱自在に連結して被
検査管の外周を回転させる一方、該探触子保持体
の周方向に複数個の探触子を設けると共に該各探
触子の前面に接触媒質を供給する注入口と供給路
を該保持体内部に設け、更に前記固定筒状体の出
口側端と前記探触子保持体の出口側に被検査管を
支持案内するガイドローラを夫々設けたことを特
徴とする。 In view of the above-mentioned points, the present invention is designed to maintain excellent flaw detection accuracy even during high-speed rotation. The structure includes a fixed cylindrical body with an introduction guide for the pipe to be inspected at the inlet end, and a rotary cylinder rotatably provided around the fixed cylindrical body. In a probe rotating type ultrasonic flaw detection device for a tubular body, which has a support mechanism that supports the rotating cylindrical body at at least two points in the longitudinal direction via bearings, the inner diameter is slightly larger than the outer diameter of the tube to be inspected. A probe holder having a rotary cylindrical body is removably connected to the outlet end of the rotary cylindrical body to rotate the outer periphery of the tube to be inspected, while a plurality of probes are arranged in the circumferential direction of the probe holder. An inlet and a supply channel for supplying a couplant to the front surface of each probe are provided inside the holder, and an outlet end of the fixed cylindrical body and an outlet side of the probe holder are covered with The present invention is characterized in that guide rollers are provided to support and guide the inspection tubes.

以下、図面に示す実施例に基づいて本考案を詳
細に説明する。固定筒状体１１は、その内部に被
検査管が通過するように筒状をなし、その入口側
端部には被検査管を案内するための導入案内具１
２を具え、該入口側端部は基体１３によつて支え
られている。この基体１３によつて支えられる固
定筒状体１１の入口側端部から出口側端部にかけ
て回転円筒体１４が回転自在に嵌着し、該回転円
筒体１４は、高速回転時にも安定性を失なわれな
いように入口側部と出口側部とに位置する軸受１
５，１６を具えた支持機構によつて長手方向に少
なくとも２点で支持されている。該回転円筒体１
４は、探触子保持体１７へ回転力を伝達すると共
に、探触子１８と外部の電気回路を接続する部分
であり、軸受１５と軸受１６との間に探触子１８
と接続するスリツプリング１９が設けられ、該ス
リツプリング１９には外部に支持される接続ブラ
シ２０が接触する。一方、回転円筒体１４の入口
側端部には、外部の駆動源と連結するプーリ２１
が嵌着する。 Hereinafter, the present invention will be described in detail based on embodiments shown in the drawings. The fixed cylindrical body 11 has a cylindrical shape so that the tube to be inspected passes through it, and has an introduction guide tool 1 at its inlet end for guiding the tube to be inspected.
2, whose inlet end is supported by a base body 13. A rotary cylindrical body 14 is rotatably fitted from the inlet side end to the outlet side end of the fixed cylindrical body 11 supported by the base body 13, and the rotary cylindrical body 14 maintains stability even during high-speed rotation. Bearing 1 located on the inlet side and outlet side to avoid loss
It is supported at at least two points in the longitudinal direction by a support mechanism comprising 5 and 16. The rotating cylindrical body 1
4 is a part that transmits rotational force to the probe holder 17 and connects the probe 18 with an external electric circuit; the probe 18 is connected between the bearing 15 and the bearing 16;
A slip ring 19 is provided which connects with the slip ring 19 and is contacted by an externally supported connecting brush 20. On the other hand, a pulley 21 connected to an external drive source is provided at the inlet side end of the rotating cylindrical body 14.
is fitted.

次に該回転円筒体１４の出口側端には、被検査
管の外周を回転する管状の探触子保持体１７が着
脱自在に連結している。該探触子保持体１７は、
その内部を通る被検査管の外周面との間に水の薄
膜を形成すように該被検査管の外径より僅かに大
きな内径を有する。該探触子保持体１７は、回転
円筒体１４と連結する一方、その出口側端部は軸
受２２を具えた支持機構によつて支えられ、前記
回転円筒体１４と一体に被検査管の外周を3000
回／分程度の高速で回転する。なお探触子保持体
の出口側端部の揺動がそれほぼ大きくない場合は
該端部の軸受は省略してもよい。被検査管は固定
筒状体１１を通り探触子保持体１７の内部を出口
へ向けて矢印Ｄ方向に進むが、ここで被検査管の
撓みを防止するために探触子保持体１７の入側と
出側に被検査管を支持案内するガイドローラー２
３と３２を設ける。入側のガイドローラー２３
は、探触子保持体１７自体が回転するので、第２
図のようにローラー支持体２４を前記固定筒状体
１１の出口側端部に嵌着して支え、被検査管の外
周にガイドローラー２３が転接するように設け
る。出側のガイドローラー３２は、軸受２２や後
述する給水管３０を支持する固定基体２８に第２
図のように取付ける。探触子保持体１７内を通過
する被検査管はガイドローラー２３と３２によつ
て支持され、この２組のガイドローラーの間隔は
小さいので、この間で被検査管が撓むことはな
い。該探触子保持体１７には、その周方向に複数
個の探触子１８が放射状に配設され、該探触子１
８の先端は、被検査管の外周面との間に僅かな間
隙を形成する。そして、この間隙で水の薄膜を形
成するための給水路２５が探触子保持体１７の内
部に設けられる。この給水路２５の注入口２６は
回転時に給水を受けるために探触子保持体１７の
外周面上に環状の溝となつている。この注入口２
６は探触子１８より出口側に設けられる一方、そ
の給水路２５は探触子１８の先端部に向つて延び
探触子１８の近傍で被検査管の外周面へ射水する
複数の射水口２７を具える。この場合、被検査管
の送り速度が非常に速くなると従来の給水圧では
移動する被検査管に付着し流出する水の量が大と
なり、水の薄膜を形成しにくくなるので探触子１
８の上流側に予備射水口２９を設け、前もつて被
検査管に水を噴射しておいて、探触子１８の位置
で水の薄膜を形成し易いようにするとよい。また
前記注入口２６との給水管３０との接続部分には
シール３１を設けて給水流を密封する。軸受２２
の潤滑油はシール３１がたとえ不具合になても回
転する探触子保持体１７の遠心力を受け排出口３
３から外部へ排出されるので給水路２５に混入す
ることはない。このように本願考案装置では探触
子の直近で接触媒質である水を供給するようにし
てあるので高速回転時においても安定した水の薄
膜形成が得られ、また探触子保持体の直前直後に
被検査管を支持案内する機構を設けたので被検査
管の撓みを防止することができ、探傷精度の信頼
が高い。 Next, a tubular probe holder 17 that rotates around the outer periphery of the tube to be inspected is detachably connected to the outlet side end of the rotating cylindrical body 14. The probe holder 17 is
It has an inner diameter slightly larger than the outer diameter of the tube to be inspected so as to form a thin film of water between it and the outer circumferential surface of the tube to be inspected passing through it. The probe holder 17 is connected to the rotating cylindrical body 14, while its outlet end is supported by a support mechanism equipped with a bearing 22, and the probe holder 17 is connected to the rotating cylindrical body 14 and integrally supports the outer periphery of the tube to be inspected. 3000
It rotates at a high speed of about 100 times per minute. Note that if the swing of the exit side end of the probe holder is not substantially large, the bearing at the end may be omitted. The tube to be inspected passes through the fixed cylindrical body 11 and moves inside the probe holder 17 toward the exit in the direction of arrow D. At this point, in order to prevent the tube to be inspected from bending, the probe holder 17 is closed. Guide rollers 2 that support and guide the pipe to be inspected on the entry and exit sides
3 and 32 are provided. Entry side guide roller 23
Since the probe holder 17 itself rotates, the second
As shown in the figure, a roller support 24 is fitted and supported at the outlet end of the fixed cylindrical body 11, and a guide roller 23 is provided so as to be in rolling contact with the outer periphery of the tube to be inspected. The guide roller 32 on the exit side is attached to a fixed base 28 that supports the bearing 22 and a water supply pipe 30, which will be described later.
Install as shown. The tube to be inspected passing through the probe holder 17 is supported by guide rollers 23 and 32, and since the interval between these two sets of guide rollers is small, the tube to be inspected will not bend between them. A plurality of probes 18 are arranged radially in the circumferential direction of the probe holder 17.
8 forms a slight gap between the tip and the outer peripheral surface of the tube to be inspected. A water supply channel 25 for forming a thin film of water in this gap is provided inside the probe holder 17. The inlet 26 of the water supply channel 25 is an annular groove on the outer peripheral surface of the probe holder 17 to receive water during rotation. This inlet 2
6 is provided on the exit side of the probe 18, while its water supply channel 25 extends toward the tip of the probe 18 and includes a plurality of water injection ports that inject water into the outer peripheral surface of the pipe to be inspected near the probe 18. Equipped with 27. In this case, if the feeding speed of the tube to be inspected becomes very high, the amount of water that adheres to the moving tube to be inspected and flows out will increase with the conventional water supply pressure, making it difficult to form a thin film of water, so the probe 1
It is preferable to provide a preliminary water injection port 29 on the upstream side of the probe 8 to inject water into the tube to be inspected in advance to facilitate the formation of a thin film of water at the position of the probe 18. Further, a seal 31 is provided at the connection portion between the inlet 26 and the water supply pipe 30 to seal the water supply flow. Bearing 22
Even if the seal 31 becomes defective, the lubricating oil will be discharged from the discharge port 3 due to the centrifugal force of the rotating probe holder 17.
Since it is discharged to the outside from 3, it does not mix into the water supply channel 25. In this way, in the device devised in the present application, since water, which is a couplant, is supplied in the vicinity of the probe, a stable thin film of water can be formed even during high-speed rotation. Since a mechanism is provided to support and guide the tube to be inspected, it is possible to prevent the tube to be inspected from bending, and the reliability of the flaw detection accuracy is high.

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

第１図は従来の探触子回転型超音波探傷装置の
例を示す断面図、第２図は本考案の超音波探傷装
置の一実施例を示す断面図、第３図は第２図の
−線に沿う断面図である。 図面中、１１は固定筒状体、１２は導入案内
具、１４は回転円筒体、１５，１６は軸受、１７
は探触子保持体、１８は探触子、２５は給水路、
Ａは回転円筒体の支持機構、Ｂは探触子保持体の
支持機構。 Fig. 1 is a cross-sectional view showing an example of a conventional rotating probe type ultrasonic flaw detection device, Fig. 2 is a cross-sectional view showing an embodiment of the ultrasonic flaw detection device of the present invention, and Fig. - is a sectional view taken along the line. In the drawing, 11 is a fixed cylindrical body, 12 is an introduction guide, 14 is a rotating cylindrical body, 15 and 16 are bearings, and 17
is a probe holder, 18 is a probe, 25 is a water supply channel,
A is a support mechanism for the rotating cylindrical body, and B is a support mechanism for the probe holder.

Claims (1)

【実用新案登録請求の範囲】[Scope of utility model registration request] 入口側端部に被検査管の導入案内具を設けた固
定筒状体と、該固定筒状体の外周に回転自在に設
けた回転円筒体と、該回転円筒体を軸受を介して
長手方向に少なくとも二点で支持する支持機構を
有する管状体の探触子回転型超音波探傷装置にお
いて、被検査管の外径より僅かに大きい内径を有
する探触子保持体を前記回転円筒体の出口側端に
着脱自在に連結して被検査管の外周を回転させる
一方、該探触子保持体の周方向に複数個の探触子
を設けると共に該各探触子の前面に接触媒質を供
給する注入口と供給路を該保持体内部に設け、更
に前記固定筒状体の出口側端と前記探触子保持体
の出口側に被検査管を支持案内するガイドローラ
を夫々設けたことを特徴とする探触子回転型超音
波探傷装置。 A fixed cylindrical body provided with an introduction guide for the tube to be inspected at the inlet side end, a rotating cylindrical body rotatably provided on the outer periphery of the fixed cylindrical body, and a longitudinal direction of the rotating cylindrical body via a bearing. In a rotary probe type ultrasonic flaw detection device for a tubular body, which has a support mechanism that supports the tube at at least two points, a probe holder having an inner diameter slightly larger than the outer diameter of the tube to be inspected is attached to the outlet of the rotating cylindrical body. It is detachably connected to the side end to rotate the outer periphery of the tube to be inspected, while a plurality of probes are provided in the circumferential direction of the probe holder, and a couplant is supplied to the front surface of each probe. An injection port and a supply path are provided inside the holder, and guide rollers are provided at the outlet side end of the fixed cylindrical body and the outlet side of the probe holder, respectively, to support and guide the tube to be inspected. Features: Rotating probe type ultrasonic flaw detection equipment.