JPS58211656A - Ultrasonic flaw detector - Google Patents

Abstract

PURPOSE:To prevent turbulence and bubbling of a flaw detection water by forming an interference prevention groove between a vibrator chamber and a high pressure jetting section. CONSTITUTION:A high water pressure is fed to a high pressure water flow port 1a of probes A and B bringing flaw detecting surfaces 27 of probes A and B into contact with a metal strip 1 to supply a flaw detection water to a flaw detection water flow port 34a. A high pressure water jets from a jetting section 30 passing through a passage 31 to form a water film between the flaw detecting surface 27 and the metal strip 1 and the flaw detection water reaches a vibrator chamber 28 passing through a passage 34 to fill the chamber 28. Although there is a pressure difference between the high pressure water and the flaw detection water, interference prevention grooves 29a and 29b provided between a high pressure water jetting port 30 and the vibration chamber 28 prevent the turbulence and bubbling of the flaw detection water. The flaw detection water has a fixed direction of flow due to a guide surface 35 and the outflow 34b thereof and combined with a bubble releasing hole communicating with the vibrator chamber 28, it won't be disabled intercepted by bubbles.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an ultrasonic flaw detection device a used for inspecting flaws in a running metal strip. .

Internal defects in metal materials include (a) foaming during casting, i.e., blowholes caused by gas components during melting and casting, and (b) inclusions during casting, i.e., non-metallic inclusions during melting and casting. can give.

In the process of rolling metal strips, air bubbles are rolled along with the metal strips, so they are discovered as very large defects such as splits in two after the product is made. The discovery of defects during inspection at the stage of product production has a significant impact on manufacturing costs, so it is necessary to provide an ultrasonic flaw detector in the middle of the rolling process.

This type of device has a flaw detector f equipped with a vibrator, and this flaw detector f is pressed against the target object while flowing detection water for ultrasonic propagation. It was being rocked at high speed while scraping the surface. Therefore, there is a problem in that the part that is in contact with the object to be tested in flaw detection f wears out in a short period of time. This wear and tear on the flaw detector not only affects the cost of replacing the flaw detector, but also causes the distance between the vibrator and the object to be tested to fluctuate, causing an extremely serious problem of lowering detection accuracy. .

The present invention has been made in view of the following points,
In an ultrasonic flaw detection apparatus for a metal strip, which includes a flaw detection r, a vibration f chamber provided on the flaw detection surface of the flaw detection P, and a vibrator attached to the vibrator chamber for transmitting and receiving ultra-U waves, the vibrator chamber A high-pressure water spouting section for spouting high-pressure water toward the metal strip on the flaw detection surface around the metal strip, and an interference prevention groove provided on the flaw detection surface between the high-pressure water spouting section and the vibrator chamber. This is related to sonic flaw detection equipment, and a water film is formed between the flaw detector and the object to be tested by ejecting high-pressure water from the flaw detector, preventing wear of the flaw detector and enabling long-term use. This also improves detection accuracy.

Next, the apparatus of the present invention will be explained with reference to the drawings.

In the figure, 1 is the material to be tested (metal strip) running along the rolling process.
During the rolling process, from the 1-stream side to the downstream side, a plate tracing detector 2 using a phototube or the like, an upstream pinch roller 3, and a plurality of flaw detection F Al-A4.
A swing frame 4 to which B, to B4 are attached, a downstream pinch roller 5 that applies a predetermined tension to the metal strip 1 in place of the upstream pinch roller 3, and a roller for marking the detected defective part. A marking device 6 using inkjet or the like is installed. Furthermore, material confirmation detectors 7 and 8 using phototubes or the like are installed near the board copying detector 2 and the downstream pinch roller 5, respectively, and the board copying detector 2 swings the swinging frame 4. It is connected to the operation stand 9, and the operation stand 9 and the plate copying detector 2 are configured to move together.

The operating stand 9 is movable along a rail IO provided in a direction perpendicular to the running direction of the metal strip 1, and is driven by a hydraulic cylinder 11.

This hydraulic cylinder 11 is controlled by a control circuit (not shown).
The plate copying detector 2 is operated so as to always capture the center of the plate material l.

Further, a swinging operation motor 12 is attached to the operation frame 9, and a rotational drive shaft of this motor 12 is provided on a rotating disk 13 and a part of the rotating disk 13, and is connected to the rotation center of the rotating disk 13. The pivot 4a of the swing frame 4 is connected to the pivot 4a of the swing frame 4 via a swing width setting adjustment screw f14 fixed to be movable in radial directions and a swing operation crank I5 pivotally connected to the screw f14. connected.

The swingable pedestal 4 has a pedestal frame 16, and a device 17 is attached to the lower surface of the pedestal frame 16 to maintain a water pressure of 1''Y. Hydraulic float I above.

The device 17 is placed on a rail 18□L provided in a direction perpendicular to the traveling direction lj of the metal strip 1 with a water film interposed therebetween, and is moved along the rail. This hydraulic flotation device has a block shape with a J-shaped cross section as shown in FIG. Further, the rail 18 shown in 1- has a substantially inverted cross-section, and from this G, a protrusion 18a is formed at the upper part of the rail 18 to protrude outward.

The floating surface 17a of the hydraulic 1/2 upper device 17 is placed on the upper end surface 18b of the rail 18, and the L protrusion 18a is wrapped around the guide portion +7b of the hydraulic floating device 17.
The guide portion 17M is engaged. Furthermore, the height 11: and four parts as the water spouting part 19 are formed on the J- marked floating surface 17a, and this height II.
High pressure water flow 19b is passed through the flow path 19a formed in 7.
communicate with. On the other hand, an arm support side frame 20 is erected on the mount frame 16. This side frame 2
A plurality of arms 23.0 are connected to each other via fulcrum shafts 21.22.
24 is pivotally mounted, and one each of the flaw detection 'F Al-A4 +B1 to B4 is attached to each tip of the arms 23 and 24. The above-mentioned fulcrum shafts 21 and 22 are held in the upper direction of the lute, and a plurality of arms 23 are fixed to the fulcrum shaft 21 located above so as to rotate together with the fulcrum shaft 21. The shaft 21 is rotated by an actuator 25 such as an air cylinder. Similarly, a plurality of arms 24 are fixed to the fulcrum shaft 22 located in the F direction so as to rotate together with the fulcrum shaft 22.
goes up to the actuator 26 such as an air cylinder and performs rotational operation. In addition, at each tip of the arm 23 located above,
- The flaw detectors A and -A4 are pivotally mounted, and each of the flaw detectors A1 to
A, are arranged at equal intervals along the running direction of the metal strip 1.

On the other hand, on the F side, each tip of the arm 24 located here (here, the lower flaw detectors 81 to B) is pivotally mounted, and the lower flaw detectors B, to B
4, metal strip 1 in the same way as -1: part flaw detectors A1 to A above.
are arranged 6 at equal intervals from each other along the running direction, and
As shown in FIG. 3, the upper flaw detection f AH~A4 and r7 are arranged so as to be different from each other.

Next, the flaw detection f-A1-A, 1 + Bl~B will be described in detail.

FIG. 7 is a cross-sectional view of flaw detectors A and B, and FIG. 8 is a flaw detection surface that comes into contact with a metal strip, which is a branch flaw detection body, through water. In the figure, 27 is a flaw detection surface, and the flaw detection surface 27 is a road surface square.
A circular vibrator chamber 28 is open in the center. Further, on this flaw detection surface 27, a circumferential 12 anti-interference groove 29a is formed along the outer periphery of the second set of vibration f-chambers 28, and a circumferential 12 anti-interference groove 29a is further formed to extend in the radial direction from the circumferential 1 anti-interference groove 29a. A plurality of radiation interference prevention m29b are formed.

Each of the interference prevention grooves 29a, 29b has a groove shape with a cross section of 1 circle.

In addition, in Juki Flaw Detection 27, the above 1 “Water V +) Jl
Four circular parts that become high-pressure water jetting parts 30 are formed at each location defined by the vibration F chamber 28 by the L-grooves 29a and 29b, and each of these high-pressure water jetting parts 30 is used for flaw detection-FA,'
They communicate with each other through a high-pressure water passage 31 formed in B, and the high-pressure water passage 31 communicates with a high-pressure water inlet 31a.

1. On the other hand, a vibrator 32 is installed in the vibrator chamber 28 at a predetermined distance from the flaw detection surface 27, and this vibrator 32 has the function of transmitting and receiving ultrasonic waves.

The outer diameter of the vibrator 32 is smaller than the inner diameter of the vibrator chamber 28, so that a water reservoir 28 is formed around the tip of the vibrator 32.
a is formed. Further, a flaw detection water channel 34 for supplying flaw detection water to the transducer chamber 28 is formed in the flaw detectors A and B, and one end of this flaw detection water flow channel 34 is connected to the flaw probes A and H.
The flaw detection water inflow port 34a is opened to the outside of the transducer chamber 28, and the other end is a flaw detection water outflow port 34b that opens near the tip of the vibrator 32 in the transducer chamber 28. This flaw detection water becomes a propagation medium of the super j' wave between the vibration f.
II: The inner wall of the transducer chamber 28 facing the s4b has an oblique guide 35, 35 to prevent the turbulent flow of the flaw detection water.

In the above configuration, when a metal strip 1, which is the material to be tested, comes, the material confirmation detectors 7 and 8 confirm this, and the upstream pinch roller 3 and the downstream pinch roller 5 pinch the metal strip 1. Apply appropriate tension to the metal strip I.

At the same time as the above-mentioned flow-side pinch roller 3 pinches the metal it, the plate copying detector 2 operates, and the hydraulic cylinder 11 is activated so that the detector 2 follows the movement of the metal strip 1 in the direction perpendicular to the flow direction. Let it operate. Since the detector 2 and the operating stand move together, the positional relationship between the operating stand 9 and the metal strip 1 is always kept constant. In this state, the actuators 25 and 26 are operated to bring the detection surfaces 27 of the flaw detectors A and B into contact with the metal strip 1, and the flaw detection -j''-A
, the pressure in the high pressure water inflow r131a of B is 3 kg/'7
It also supplies high-pressure water of approximately
A deep field 4 (with a pressure of about 0.2 kg-'i) is supplied.

The high-pressure water passes through a high-pressure water flow path 31 to a high-pressure water spout section 30.
A water film is formed between the flaw detection surface 27 and the metal strip 1, and the flaw detection water passes through the flaw detection water flow path 34 and reaches the transducer chamber 28. It will be filled with flaw detection water. At this time, there is a pressure difference between the high pressure water and the flaw detection water, but the high pressure water jet 1''3o and the vibration -
Since there are interference prevention grooves 29a and 29b between the F chamber 28 and the F chamber 28, turbulent flow and bubbling of the flaw detection water are prevented. In addition, the flaw detection water flows in a fixed direction due to the guide 35 and the flaw detection water outflow 34b, and since there is a bubble removal hole 33 communicating with the transducer chamber 28, the ultrasonic waves are blocked by bubbles and flaw detection becomes impossible. There is no fear. Next, the height of the hydraulic flotation device 'f17 provided on the lower surface of the gantry frame 16 is 11:, the water flow population is 19
When high-pressure water is supplied to b and is ejected from the high-pressure water spouting part 19, a water film is formed between the floating surface 17a and the upper end 18b of the rail 18, and the flaw detection P pedestal 4 can freely slide on the rail 18. The state will be as follows. , 2 When the swing operation motor 12 is driven, the rotational motion of the motor 12 is changed into a linear motion by the rotating disk 13 and the swing operation crank 15, and the flaw detection frame 4 is perpendicular to the running direction of the metal strip 1. As a result, the flaw detection unit A and B swing in the Jj direction to ' ゛),.

-1 The swing width of the flaw detection frame 4 is determined by the distance from the center of rotation of the rotating disk 130 to the pivot position of the crank 15, but in this embodiment, the swing width for adjusting the distance is Since setting adjustment screws F-1 and F-4 are provided, the swing width of the flaw detection frame 1σ) can be set as desired. In addition, the total weight of the flaw detection stand 4 is approximately H1Okg;
Even if repeated rocking of /lJ+oOm/min is performed at 41 cycles/second, the frictional force between the rail 18 and the 7"Pl: device 17 is extremely small due to the water film, so the rail 18 and the flotation device 2217 are affected by IJll. The shock is very small.The above flaw detection f-A.

When a defect in the metal plate I is discovered by B, (1) the position of the defect in the swing direction is determined from the rotational position of the crank 15, the number of revolutions of the downstream pinch roller 5 is counted by a pulse generator, and the defect is detected. The distance from the position to the marking device 6 is calculated, and when the defective location reaches the position of the marking device 6, marking is performed.

As explained above, according to the present invention, high-pressure water is ejected from the flaw detector to form a water film between the flaw detector E and the object to be detected, so that This has the effect of preventing wear on the contact surface of the flaw detector, and allows long-term use without the need to replace the flaw detector. Moreover, since there is no fear that the distance between the vibrator and the object to be inspected will change due to wear, the detection accuracy will not deteriorate, and the detection accuracy, which is the lifeblood of such a device, can be maintained at a high level of accuracy.

According to the present invention, since the interference prevention + and I- grooves are formed between the vibrator chamber and the high-pressure water spouting part, there is a pressure difference between the flaw detection water flowing through the vibrating chamber and the high-pressure water. There is no risk of turbulent flow or foaming of the flaw detection water even if it exists.

[Brief explanation of the drawing]

The figures show one embodiment of the device according to the present invention, and FIG. 1 is a front view showing the operating stand portion of the device. , Fig. 3 is a side view of the main parts of the device, Fig. 4 is an explanatory diagram showing the locus of the flaw detector r on the object to be tested, Fig. 5 is a side view showing the flaw detector mount, and Fig. 6 is a side view of the main part of the device.
The figure is a sectional view taken along the ■-■ line in Figure 5, and Figure 7 is a flaw detection f
8 is a cross-sectional view of the flaw detector viewed from the flaw detection surface side. 1... Metal strip, 27... Flaw detection surface, 28... Vibration r
Chamber, 29a, 29b...interference prevention groove, 30...high pressure main jetting part, 32... vibrator, A, B... flaw detector. Patent applicant Nippon Mining Co., Ltd. Affiliated with Nippon Cloud Claimer

Claims (1)

[Claims] Detector If, a vibration chamber F provided on the detection surface of this flaw detector, and a vibration E installed in this vibrator chamber that transmits and receives ultrasonic waves.
The ultrasonic detection device 1b for a metal strip includes a high-pressure water spouting section that spouts high-pressure water toward the metal strip on a flaw detection surface around the vibrator chamber, and a connection between the high-pressure water spouting section and the vibrator chamber. A super?゛9
Wave flaw detection equipment.