JPS58211654A - Ultrasonic flaw detection - Google Patents

Abstract

PURPOSE:To achieve a highly reliable ultrasonic flaw detection free from damage for a long time by rocking an oscillating frame base floating on a rail by a high pressure water. CONSTITUTION:As soon as a metal strip 1 is grasped with an upstream pinch roller, actuators 25 and 26 are started to bring flaw detection surfaces 27 of probes A and B into contact with the metal strip 1, setting it at the starting position. A high pressure water is fed to a high pressure water flow port at a water pressure floating position 17 provided on the undersurface of the base frame 16 and as it is jetted from a high pressure water jetting section, a water film is formed between a floating surface and the upper end face of a rail 18 to make an oscillating frame base 4 slide freely on the rail 18. When an oscillating motor 12 is driven, a rotary motion is converted to a linear motion with a rotary disc 13 and a crank 15 so that the frame base oscillates in the direction perpendicular to the running direction of the metal strip 1.

Description

[Detailed description of the invention]

The present invention relates to an ultrasonic flaw detection method for a running metal strip. Internal defects in metal materials include a. Bubble generation during casting, i.e., blowholes caused by gas components during melting and casting; b. Inclusions during M-filling, i.e., non-metallic inclusions during melting and casting. . During the rolling process of the metal strip, air bubbles are also present (this is why after the product is rolled, very large defects such as splitting into two pieces are discovered. If a defect is discovered during an inspection at this stage, it will have a large impact on manufacturing costs, so it is necessary to install an ultrasonic flaw detector a during the rolling process. The device consists of a swinging mount that swings a flaw detection tool equipped with a vibrator in a direction perpendicular to the traveling direction of the object to be tested.This swinging mount usually weighs about 100 kg and is used for flaw inspection. Since this rocking frame is repeatedly rocked at 9 m/min and 00 m/min at a rate of 1 cycle/second, a strong shock is applied to the sliding surface of the rocking frame. Bearings were used on the sliding surface of the above-mentioned rocking platform.However, since these ultrasonic flaw detection devices use water to propagate ultrasonic waves, the bearings may rust or break due to strong shock. There was a problem.Also, it is possible to use grease on the metal sliding surface, but in this case, in order to use water,
There was a problem in that the grease was washed away by water, and in winter, the grease itself hardened because it was constantly cooled by water, making the movement of the mount slow. The present invention has been made in view of this point, and is used in an ultrasonic flaw detection method for a running metal strip. High-pressure water is jetted onto the rail to float the swinging platform on the rail. The present invention relates to an ultrasonic flaw detection method for a running metal strip, in which flaw detection is performed by swinging a swinging frame supporting the probe 1F along the rail. This overcomes the traditional problems and provides long-term

[We were able to provide a highly reliable ultrasonic flaw detection method that does not cause damage due to passing. Next, the method of the present invention will be explained with reference to the drawings. In the figure, 1 is the material to be tested (metal strip) that runs along the rolling J2 line, and during the rolling process, from the 1- stream side to the F stream side, there are various plates such as phototubes. Detector 2 and 0
, ”-stream side pinch roller 3 and a plurality of probes (m f A
The rocking frame 4 to which l~A, , B, ~B are attached, and the downstream pinch roller 5 that applies a predetermined tension to the metal strip 1 together with the downstream pinch roller 3 are detected. A marking device using an inkjet or the like is installed to mark defective areas.Furthermore, a material confirmation detector 7 using a phototube or the like is installed near the board copying detector 2 and the downstream pinch roller 5, respectively.
. The operating stand 9 is movable along a rail 10 provided in a direction perpendicular to the running direction of the metal strip 1, and is driven by a hydraulic cylinder 11. This oil pressure cylinder 11 is driven and operated by a control circuit (not shown) so that the plate copying detector 2 always captures the center of the plate material l. Further, a swinging operation motor 12 is attached to the operation frame 9, and the rotational drive shaft of this motor I2 is provided on the rotating disk 13 and a part of the rotating disk 13, and is connected to the rotation center of the rotating disk 13. Connected to the pivot portion 4a of the swing frame 4 via a swing width setting adjustment screw F14 fixed so as to be movable in the radial direction, and a swing operation crank 15 pivotally mounted to the screw F14. has been done. The swingable pedestal 4 has a pedestal frame 16, and a hydraulic flotation device 17 is attached to the lower surface of the pedestal frame 16. The hydraulic flotation device 17 is placed on a rail 18 provided in a direction perpendicular to the traveling direction of the metal strip 1, with a water film interposed therebetween, and is movable along the 0-rail. This hydraulic flotation device has a block shape with a J-shaped cross section as shown in FIG. Furthermore, the rail 18 has a substantially inverted cross-section, so that a portion of the rail 18 is formed with a protrusion 18a that protrudes outward. Said water II:, float 1 on the upper end surface 18b of said rail 18;
Floating type: The floating surface 17a of the device is placed thereon, and the protruding portion 18a is engaged with the guide portion 17b of the device 17 by wrapping it around the hydraulic float. Furthermore, the floating surface 7a is formed with four parts as high-pressure water spouting parts 19, and these high-pressure water spouting parts 19 are capable of discharging high-pressure water through flow channels 19a formed in the flotation device 17. It communicates with the water flow population 19<'-'G'-''.On the other hand, an arm supporting side frame 20 is erected on the pedestal frame 16.This side frame 20
A plurality of arms 23.2 are connected to each other via a fulcrum shaft 21.22.
4 is pivotally mounted, and the flaw detection F Al-A4. Install one each of B and -B4. The above-mentioned fulcrum shaft 21. 22 are held parallel to each other, 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, and this fulcrum shaft 21 is attached to an air cylinder, etc. Climb up to the actuator 25 and perform rotational operation. Similarly, a plurality of arms 24 are attached to the fulcrum shaft 22 located below.
2, and the fulcrum shaft 22 is rotated by an actuator 26 such as an air cylinder. In addition, one part of the flaw detectors A1 to A is pivotally attached to each tip of the arm 23 located at "2", and each of the flaw detectors F
Al~A. are arranged at equal intervals along the running direction Jj of the metal strip l. On the other hand, each tip of the arm 2.1 located below [the upper flaw detector f-BI~B] is pivotally mounted, and the lower flaw detector B1~
``Two sets'' of B4 were placed at equal intervals from each other along the direction of travel to the subordinate strip in the same way as ``two sets'' of partial flaw detection: F-Al~A, and as shown in Fig. 3, - Arrange so as to alternate with A4. In the above configuration, when the metal strip 1, which is the material to be inspected, comes, the material confirmation detector 7.8 confirms this, and the second-stream pinch roller 3 and the downstream pinch roller 5 pinch the metal strip 1. Apply appropriate tension to the metal strip 1. At the same time as the upstream pinch roller 3 pinches the metal strip 1, 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. 1- Since the detection unit 42 and the operating stand move together, the positional relationship between the operating stand 9 and the control strip 1 is always kept constant. In this state, operate the actuators 25 and 26 to
The flaw detection surface 27 is brought into contact with the metal strip 1 and the flaw detection is set at the starting position. Next, the hydraulic floating position 17 provided on the underside of the gantry frame 16
When high-pressure water is supplied to the high-pressure water flow population 19b and ejected from the high-pressure water jetting part 19, a water film is formed between the floating surface 17a and the upper end surface 18b of the rail 18, and the swinging frame 4 is moved onto the rail 18. It will be in a state where it can slide freely. When the swing operation motor 12 is driven, the rotational motion of the motor 2 is converted into a linear motion by the rotating disk 13 and the swing operation crank 15, and the swing mount is moved in a direction perpendicular to the running direction of the metal strip 1. to sway. As a result, the flaw detector A is attached to the swing frame 4. B conducts flaw detection by drawing flaw detection trajectories on both sides of the metal strip 1 as shown in FIG. As explained above, according to the present invention, the pedestal is floated by high-pressure water and the water acts as a lubricant, so that the sliding resistance between the rail and the pedestal is extremely small. Therefore, even if the swinging platform, which is a fairly heavy asset, swings at high speed, the shock applied to the rails and floating surface will be extremely small, and the durability of the equipment will be dramatically improved. There is little variation due to external conditions such as temperature, and reliability has been greatly improved.

[Brief explanation of the drawing]

The figures show one embodiment of the apparatus used in the method according to the present invention, and FIG. 1 is a bottom view of the apparatus [ffi, FIG. The figure is a side view of the main parts of the device, Figure 4 is an explanatory diagram showing the locus of the flaw detector on the object to be tested, and Figure 5 is a side view showing the flaw detection r-mount.
FIG. 6 is a sectional view taken along the line ■--■ in FIG. 5.

Claims (1)

[Claims] Ultrasonic flaw detection method for running metal strips (here, flaw detection F)
Water is jetted from the bottom of the swinging platform that supports the rails, which are laid in a direction perpendicular to the running direction of the metal strip, to float the swinging platform above the rails, and An ultrasonic flaw detection method for a running metal strip, which performs flaw detection by swinging a swinging frame supporting the flaw detection r.