JPH0762673B2 - Ultrasonic automatic flaw detector - Google Patents

Description

TECHNICAL FIELD The present invention relates to an ultrasonic automatic flaw detector, and more specifically, it is an ultrasonic automatic flaw detector for full-scale flaw detection of a thick plate in a steel plate manufacturing line in a steel mill or the like. It relates to the device.

(B) Conventional technology Conventionally, online ultrasonic automatic flaw detection of a steel sheet was performed by scanning the steel sheet in the conveying direction (Y direction). Therefore, the probe can be moved to the leading end (top) and the trailing end (bottom) of the steel sheet. No follow-up was necessary.

In general, the flaw detection equipment installed in the steel plate production equipment,
The inclination of the steel sheet with respect to the transport direction of the steel sheet was small enough to be neglected, and there was no problem with the edge tracking of the probe. However, in recent years, as the quality of products has advanced and strict quality assurance has been required, it has become necessary to automate the flaw detection of steel sheets and make it semi-online. For this reason, there is a device in which a plurality of probes are arranged at regular intervals, forward scanning is performed in the X direction, and then the entire surface is flaw-detected by shifting in the Y direction by a constant interval and scanning in the backward X direction (JP-A-59-133457). ). However, with this device, it is difficult to perform flaw detection near the peripheral edges of the steel sheet, and it was necessary to provide flaw detection units dedicated to the front, rear, left, and right edges, in addition to the above-described full-face flaw detection unit. There is also proposed a device in which an edge detector is additionally provided in the full-face flaw detection unit so that the front and rear end units can be shared by the full-face flaw detection unit (Japanese Patent Laid-Open No. 59-105559). However, all of these are effective when the steel plate is parallel to the XY direction, and the occurrence of an undetected area is unavoidable in the oblique steel plate that occurs when the steel plate is carried in by a crane or the like offline. .

A local immersion method is generally used for the probe, and since the probe contacts the steel plate through a water film, if any part of the probe pops out from the edge of the steel plate, flaw detection water will flow out and no water film will be formed. The probe directly contacts the steel plate, causing damage such as wear.

(C) Problem to be Solved by the Invention The problem to be solved by the present invention is to provide a reliable follow-up mechanism for the front and rear end portions of the material to be inspected so that an undetected area is generated even if the material is skewed. To prevent the problem.

(D) Means for Solving the Problem The ultrasonic automatic flaw detection apparatus of the present invention performs flaw detection by scanning the probe group in the X direction orthogonal to the Y direction while conveying the material to be inspected in the Y direction. In an ultrasonic automatic flaw detection apparatus, a head holding a plurality of probes is arranged in the Y direction to form a flaw detection unit, and a drive mechanism for moving the unit in the X and Y directions within the machine frame of the apparatus, and the unit. A drive mechanism for selectively moving the heads at both ends in the Y direction, and a scanning controller for commanding the movement of the both end heads in the Y direction in accordance with the output of the edge detector arranged on the both end heads. Together with the skew detector for detecting the skew of the material to be inspected in the flaw detection unit, and the inclination calculator for instructing the head positions at both ends at the start of flaw detection in accordance with the detected skew direction, the above problem is solved. Has been resolved.

(E) Embodiment An embodiment of the automatic ultrasonic flaw detector of the present invention will be described with reference to the drawings.

FIG. 1 shows a schematic configuration diagram of an ultrasonic automatic flaw detector according to the present invention. A general ultrasonic automatic flaw detection apparatus performs flaw detection by conveying a material to be inspected such as a thick plate in the Y direction and scanning a probe group in the X direction orthogonal to the Y direction. In the ultrasonic automatic flaw detection device of the present invention, the head 1 holding the plurality of probes 11 is moved to the Y direction.
The flaw detection unit 10 is configured by connecting in series in the direction.

The unit 10 is driven in the X direction by the flaw detection unit X direction drive mechanism 2 attached to the machine frame of the present apparatus. unit
The front head 1a and the rear head 1b at both ends of 10 are supported so as to be movable in the Y direction, and the front head Y direction drive mechanism
The heads 1a and 1b are driven in the Y direction by the Ya driving mechanism 3b and the trailing head 3a.

An X-direction drive controller 4 and scanning controllers 5a and 5b are connected to the drive mechanisms 2, 3a and 3b, respectively. Edge detectors 111a and 111b are attached to the heads 1a and 1b at both ends, respectively.
Is provided. The skew detector 112 is an edge detector 112a, 11 provided at a reference side end of the flaw detection unit 10 at a predetermined distance.
2b, and sends the detection signals from the edge detectors 112a and 112b to the inclining material inclining machine 6 for inspecting the Y of the inspecting material.
The tilt direction regarding the direction is calculated. The computer 6 sends a Y direction flaw detection start position signal to the controller 5a or 5b based on the tilt direction.

Each head 1a, 1b by sending the detection signal from the other edge detector 111a, 111b of each head 1a, 1b to the controller 5a, 5b, respectively.
Controls 1b edge tracking.

FIG. 2 shows a state in which the inspection material 7 is skewed. The figure (A) shows a state in which the inspected material 7 is tilted counterclockwise by + θ _{1 with} respect to the Y direction. The diagram (B) shows a state in which the inspected material 7 is tilted clockwise by −θ _{2 with} respect to the Y direction.

When tilted as shown in FIGS. 2A and 2B, the heads 1a and 1b at both ends of the unit 10 perform scanning indicated by broken lines when the edge tracking control is not performed.
However, when the edge tracking control is performed, the range shaded by a solid line is scanned.

(F) Operation The operation of the device of the present invention will be described with reference to FIG.

First, the inspected material 7 is conveyed to the flaw detection position by the conveyor and stopped (A).

Next, the flaw detection unit 10 must be moved to the scanning origin. In order to do this, first, the unit 10 is placed on the central portion of the inspected material 7 (B).

Next, while moving the unit 10 to the reference side in the X direction,
The presence and direction of the skew feeding is determined depending on which of the skew feeding detectors 112a and 112b has detected the edge first (C). Alternatively, the inclination angle (θ) can be calculated by measuring the distance until the other detector next detects an edge. Based on the detection result, the tip head 1a is moved closer to the center side in the illustrated example (D). If the skew direction is opposite, the tip head 1a is located away from the head.

In this state, the unit 10 is moved to the scanning origin (scanning start point) (E). To move, move the unit 10 in the Y direction,
Stop at the position where the edge is detected by the edge detector 111a of the tip head 1a.

Heads 1a or 1b at both ends (tip head 1
Unit 10 while making a) follow the edge of the inspected material 7
Is moved in the X direction (F).

The scanning trajectory of the unit 10 is shown in FIG. The edge of the inspected material 7 is scanned by the first X-direction scanning (A).
Next, the one-end head 1a or 1b is returned to its original position, and the unit 10 is displaced by one head in the Y direction (B). Then, the return X-direction scanning is performed (C). This completes the flaw detection on the entire surface by the unit width, so that the material 7 to be inspected is fed in the Y direction by the unit width and is scanned.

When the scanning progresses and reaches the rear end of the inspected material 7,
The other one end head (head 1b in the illustrated example) of the both end heads may be made to follow the edge in the same manner as described above.

As shown in FIG. 4 (C), regions 71 near both edges in the longitudinal direction of the material to be inspected 7 are undetected regions. But,
This area 71 has no problem because flaw detection has been completed in advance by another Y-direction edge probe head.

As the drive mechanism of the probe heads 1a and 1b at both ends, a feed mechanism including a conventional servo motor, feed screw, and guide rod may be used. When moving the head, edge detector 111
Since the position detection signals from a and 111b are constantly fed back as a correction signal, accurate edge tracking is possible.

(G) Effect According to the present invention, the front and rear edge flaw detection heads can be shared in the whole flaw detection unit, and can be followed even by the bank steel plate.
The undetected area can be eliminated, the number of inspection heads can be reduced, and the device can be downsized.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of an ultrasonic automatic flaw detector according to the present invention.
FIG. 2 is an explanatory view showing skew of the material to be inspected. FIG. 3 is an explanatory view showing the operation of the device of the present invention. FIG. 4 is an explanatory view showing a scanning result of the apparatus of the present invention. 1: Probe head, 1a: Front head 1b: Rear head, 7: Inspected material 10: Flaw detection unit, 11: Probe 111a, 111b, 112a, 112b: Edge detector

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Hiroshi Kawasaki, No. 3 Hikari, Kashima-machi, Kashima-gun, Ibaraki Prefecture Sumitomo Metal Industries, Ltd. Kashima Steel Works (72) Inventor, Shunichi Kimura, No. 3 Hikari, Kashima-machi, Kashima-gun, Ibaraki Prefecture Sumitomo Metal Industries, Ltd. Kashima Works (72) Inventor Shigeaki Matsumoto 1 Higashimukaijima Nishinocho, Amagasaki City, Hyogo Prefecture Sumitomo Metal Engineering Co., Ltd. (72) Inventor Yoshio Udagawa 728 Hishie, Higashiosaka, Osaka Japan Crow Toclaimer Felster Co., Ltd. Osaka Office (72) Inventor Fumio Yoshikawa 5156-3 Higashizaka, Nakamachi, Nara City, Nara Prefecture (56) References JP-A-59-105559 (JP, A) Practical application Sho-52-136677 (JP, U)

Claims (1)

[Claims] 1. An ultrasonic automatic flaw detector for carrying out flaw detection by scanning a probe group in an X direction orthogonal to the Y direction while conveying a material to be inspected in the Y direction, and holding a plurality of the probes. A flaw detection unit is formed by arranging the heads in the Y direction, and a drive mechanism for moving the units in the machine frame of the apparatus in the X and Y directions, and heads at both ends in the unit are selectively moved in the Y direction. And a drive controller for instructing the heads of both ends to move in the Y direction according to the output of the edge detectors arranged on both end heads. An ultrasonic automatic flaw detector, comprising a row detector, and an inclination calculator that indicates the positions of both heads at the start of flaw detection according to the detected skew direction.