JPH0454449Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a position detection device for an object in a rotary ultrasonic flaw detection apparatus that detects flaws by rotating a probe around the object.

[Prior Art] Conventionally, in this type of rotary ultrasonic flaw detection device, an eddy current type position detection device has been used as the position detection device, and as shown by the imaginary line in Fig. 2, the sensor The coil 1 is placed on the stationary side, and flaw detection is started after the sensor coil 1 senses the object and the time required for the object to move to the probe of the ultrasonic flaw detection device is taken into account. It was common.

[Problems to be Solved by the Invention] However, the object position detecting device in the conventional rotary ultrasonic flaw detection device described above has the following drawbacks.

In other words, since the sensor coil is placed on the stationary side, the distance between the position where the object to be inspected and the probe of the flaw detection device tends to be long, and the error in the estimated travel time for the object tends to be large. However, if this error is taken into account, the flaw detection time becomes longer, and flaw detection cannot be carried out efficiently.

The present invention was developed to solve the above problems, and is a rotating ultrasonic flaw detector that can reduce the time required to move the test object from detection of the test object to the start of flaw detection, thereby reducing the error in estimated time. An object of the present invention is to provide a position detection device for a subject in an apparatus.

[Means for Solving the Problems] The present invention provides a position detection device for a test object in a rotary ultrasonic flaw detection device in which flaws are detected by rotating a probe around the test object. A sensor coil of an eddy current position detection device is provided on the rotating probe side of the flaw detection device, a signal line of the sensor coil is formed into a loop coil concentric with the rotation center of the probe, and the loop coil A magnetic core rotatably coupled to the loop coil through a groove is arranged on the stationary side, an eddy current detection circuit is provided on the stationary side, and a signal line drawn out from the input/output terminal of the circuit is connected to the magnetic core. A rotating device characterized in that the signal line loop is wound around a core to form a signal line loop, and the signal line loop on the eddy current detection circuit side and the loop coil on the sensor coil side are electromagnetically coupled via a magnetic core. This is a device for detecting the position of an object to be inspected in an ultrasonic flaw detection system.

[Function] In this invention, the signal line loop on the eddy current detection circuit side and the signal line loop on the sensor coil side pass through the magnetic core, so the signals from both are electromagnetically transmitted via the magnetic core. be done. In other words, since the signal line on the eddy current detection circuit side and the signal line on the sensor coil side are not mechanically connected, signal transmission can be performed without contact, and the detection between the sensor coil and the ultrasonic flaw detection device is possible. It is possible to bring the children as close as possible.

[Example] An example of the present invention will be described with reference to the drawings.

<Configuration of Example> FIGS. 1 and 2 show the configuration of an example of a position detecting device for a subject in a rotary ultrasonic flaw detection apparatus according to the present invention.

An object position detection device 20 is attached to a probe rotation type ultrasonic flaw detection device 10 . That is,
At the end of the ultrasonic flaw detection device 10, probes 11 and 1 are installed.
A rotary flaw detection section 12 equipped with a guide tube 1 is provided, and a rotary tube 13 that rotates integrally is fixed to the rotary flaw detection section 12, and a guide tube 1 fixed to a stationary part.
4 extends through the rotary cylinder 13 toward the rotary flaw detection section 12 . The guide tube 14 has a guide hole 14a through which the subject W is inserted. Rotating flaw detection section 1
A sensor coil 30 of the position detection device 20 is attached to the probe 2 in close proximity to the probes 11, 11.

The position detection device 20 transmits signals between a sensor coil 30 that rotates integrally with the rotary flaw detection section 12 and an eddy current detection circuit 21.

A signal line 31 extends from the sensor coil 30 to the connector 15, where it joins the coaxial cable 16 coming from the probes 11, 11, and a signal line 32 connected to the signal line 31 extends into the rotating cylinder 13. has been done. In the middle part of the rotary tube 13, the rotary flaw detection section 12
A ring-shaped signal line loop 40 is formed around the rotation center O1 of the rotating cylinder 13.

The end of the coaxial cable 16 is configured to be transmitted to the main body of the flaw detection apparatus (not shown) at another location via a suitable transmission means.

The signal line loop 40 passes through the magnetic core 22 fixed on the stationary side. A groove 23 is provided in the magnetic core 22, and the signal line loop 40 is inserted through the groove 23 through the magnetic core 22.

The tip of a signal line 51 connected to the eddy current detection circuit 21 extends to the magnetic core 22 , and the tip thereof is wound around the magnetic core 22 to form a signal line loop 50 . Thereby, the signal line loop 40 and the signal line loop 50 are electromagnetically coupled via the magnetic core 22.

<Operation of the embodiment> Next, the operation of the embodiment configured as described above will be explained.

When a current I1 that generates an induced current in the sensor coil 30 is sent through the signal line 51 from the eddy current detection circuit 21 side, a change in the magnetic flux F is transmitted to the magnetic core 22 through which the signal line loop 50 on the eddy current detection circuit 21 side passes. induce.

Due to this change in magnetic flux F, an induced current I2 is formed in the signal line loop 40 on the sensor coil 30 side that penetrates the magnetic core 22, and an induced current is induced in the sensor coil 30 by this induced current I2. When the subject W passes through the guide hole 14a of the guide tube 14 and enters the electric field of the sensor coil 30, an eddy current is generated, and due to the induction effect caused by the eddy current, the sensor coil 30 detects a change in its impedance.

When a current indicating that the object W has been detected is sent from the sensor coil 30 to the signal line loop 40, it is converted into a change in the magnetic flux F of the magnetic core 22, and this change in magnetic flux F causes a signal current to flow through the signal line loop 50. This signal current is input to the eddy current detection circuit 21 via the signal line 51.

Having detected the proximity of the object W, the main body of the flaw detection apparatus sends an excitation current to the probe 11 via the coaxial cable 16 to perform flaw detection on the object W.

By the way, in this embodiment, when the probe 11 and the rotary flaw detection section 12 rotate, the signal line loop 40 also rotates, but the signal line loop 40 can freely rotate while being inserted into the fixed magnetic core 22. ,
Since the electromagnetic coupling relationship with the magnetic core 22 does not change, signal transmission is not affected at all.

Since the distance between the part where the sensor coil 30 is provided and the probe 11 is close, the time from detecting the subject W to operating the probe 11 is short.
This reduces the error in estimated time, reduces the detection dead zone, and increases efficiency.

[Effects of the invention] As explained above, the present invention allows the sensor coil of the eddy current type position detection device to be brought as close as possible to the probe of the ultrasonic flaw detection device, and
It is possible to stably transmit the detection signal of the object without contact, and it is possible to reduce the flaw detection dead zone and increase flaw detection efficiency.

[Brief explanation of the drawing]

Fig. 1 is a conceptual perspective view showing the configuration of an embodiment of the position detection device of a subject in a rotary ultrasonic flaw detection device according to the present invention, and Fig. 2 is a sectional view of the main parts of the rotary ultrasonic flaw detection device. be. 10... Ultrasonic flaw detection device, 11... Probe, 2
0...Object position detection device, 22...Magnetic core, 30...Sensor coil, 40, 50...Signal line loop, 41, 51...Signal line.

Claims (1)

[Scope of Claim for Utility Model Registration] A device for detecting the position of an object in a rotary ultrasonic flaw detection device in which flaws are detected by rotating a probe around the object. A sensor coil of an eddy current position detection device is provided on the probe side, a signal line of the sensor coil is formed into a loop coil concentric with the rotation center of the probe, and the loop coil is rotatably divided. A magnetic core coupled to the loop coil via a groove is provided on the stationary side, an eddy current detection circuit is provided on the stationary side, and a signal line drawn out from the input/output terminal of the circuit is wound around the magnetic core to generate a signal. A rotary ultrasonic flaw detection device characterized in that a wire loop is formed, and the signal wire loop on the eddy current detection circuit side and the loop coil on the sensor coil side are electromagnetically coupled via a magnetic core. Object position detection device.