JPS6394153A - Ultrasonic flaw detecting method - Google Patents

Abstract

PURPOSE:To improve operability by providing a probe surface and wheels to the bottom part of a holder, and displacing a contacting medium which is present in the fine gap between the probe surface and a material to be inspected to below the probe surface. CONSTITUTION:A probe 10 is fixed to the holder 1, the probe surface 12 is formed at its lower end, and an acoustic wave is sent to and received from the flaw detection surface of the material A to be inspected, thereby performing flaw detection. Further, front wheels 6 and 7 and a rear wheel 8 are provided to the bottom part of the holder 1, the probe surface 12 and the flaw detection surface of the material A to be inspected are held at a constant interval, and the contacting medium W is placed between them. Then, when the probe surface 12 is scanned in an X direction, the contacting medium W is pressed by the rear wheel 8 through between the front wheels 6 and 7 to gather. So it is present in the fine gap between the probe surface 12 and the flaw detection surface of the material A to be inspected all the time. Thus, the contacting medium is collected by the wheels on the bottom surfaces of the holder, so the detection signal of the probe is accurately outputted to improve the accuracy of the flaw detection.

Description

DETAILED DESCRIPTION OF THE INVENTION "Industrial Application" The present invention relates to an ultrasonic flaw detection method for detecting flaws in metal plates and the like.

"Conventional technology" Ultrasonic flaw detection, which detects flaws in metal materials using the pulse reflection method, employs direct contact methods and water immersion methods. Flaw detection is performed using immersion methods, etc. For example, in the total immersion method shown in Figure 5, the test material A and probe B are completely immersed in water in a water tank O for ultrasonic flaw detection, and in the local water immersion method shown in Figure 6, In a method called the water washing method or the water jet method, water is sent to the case E containing the probe B, and while the probe B is placed over the bottom surface of the material A to be tested, the flaws are detected. In the method using a capsule 7 as shown in Fig. 7, a capsule F with a probe B and a water container sealed inside and a bottom portion closed with a plastic film G is placed on the top surface of the material to be tested A, and this film G and the capsule F are placed on top of the material to be tested A. A flaw detection method is used in which a couplant such as water or oil is interposed between the flaw detection surfaces of the test material A.

In addition, the distance between the probe surface of probe B and the flaw detection surface of test material A is not set to a large distance as in each of the water immersion methods described above, but rather as an extremely small gap as in the direct contact method. In the gear immersion method as shown in Figure 8, the distance between the probe surface of probe B housed in holder H with an open bottom and the flaw detection surface of test material A is α3 to α8II + Flaw detection is carried out by moving the holder H onto the upper surface of the test material A while feeding water from the hose J into the holder H.

"Problems to be Solved by the Invention" None of the conventional flaw detection methods described above had good workability. For example, in the above-mentioned total submersion method shown in Figure 5, the test material is placed in the water tank 0, which is not only inapplicable to large test materials, but also requires high equipment and miscellaneous expenses. The water stool method cannot be applied to heavy test materials, and the capsule method shown in Figure 7 cannot maintain a constant detection ability when the amount of couplant varies. In addition, in the gear immersion method shown in Figure 8, a hose J extends from a faucet K of an electric hood L connected to a monitor M and is connected to a holder H, as shown in Figure 9.
Since the probe is scanned over the test material A by hand, the hose J gets wrapped around it, making it difficult to work. There was a problem that it was easy to fluctuate and a constant detection ability could not be obtained.

Therefore, the present invention provides an ultrasonic flaw detection method that does not have the above-mentioned problems, has good workability, and has stable detection ability.

"Means for Solving Intermediate Points" In order to solve the above-mentioned problems, the ultrasonic flaw detection method of the present invention uses In this method, ultrasonic flaw detection is performed by interposing a couplant between the probe surface and the flaw detection surface, while maintaining a very small distance between the probe surface and the flaw detection surface. The wheels gather the couplant below the probe surface as the surface is scanned.

``Function'' The wheels installed at the bottom of the holder maintain a constant distance between the probe surface of the probe and the flaw detection surface of the material under test, and also allow the probe to move over the material under test. This wheel gathers the couplant below the probe surface.

"Embodiments" Examples of the present invention will be described below with reference to FIGS. 1 to 4. FIG. 1 shows the top of the ultrasonic flaw detection device used in the ultrasonic flaw detection method of the present invention, FIG. The figure shows the relationship between wheel movement and couplant.

1 and 2, 1 is a holder, 2 is a probe insertion hole provided vertically in the center of the holder, 3 is a shoulder at the upper end of the insertion hole, and 4 is a probe insertion hole provided from the side of the holder. A screw hole 5 penetrating toward the insertion hole 2 is a fixing screw screwed into the screw hole 4.

6.7.8 are wheels provided at the bottom of the holder 1. Of these wheels, 6.7 are front wheels and are provided on both sides of the front end of the bottom of the holder 1, and 8 is a wheel so that the direction can be changed freely. The rear wheel is provided at the center of the rear end of the bottom of the holder 1. 9
is the axis of each wheel.

Reference numeral 1o denotes a probe, which is inserted into the above-mentioned insertion hole 2, and the flange 11 at the upper end of the probe is hooked to the shoulder 3 at the upper end of the insertion hole, and the sound wave transmitting/receiving port at the lower end of the probe is attached. A probe face 12 having
The probe 10 is made to protrude from the bottom of the holder 1, and the side surface of the probe 10 is pressed and fixed with the aforementioned fixing screw 5. 13 is probe 1
It is an electrical cord that extends from 0 and connects to the monitor.

The wheels 6.7.8 are used to maintain a constant distance between the probe surface 12 of the probe 10 and the flaw detection surface of the test material, preferably in the range of about 0.2 mm to 0.414 mm. The diameter and mounting height of each wheel 6.7.8 and the fixed position of the probe 10 are set so as to maintain the distance between the wheels 6.7.8.

The electric cord 13 extending from the probe 1o attached to the holder 1 as described above is connected to the monitor 14 as shown in the third figure, and the holder l is connected to the test material A such as a metal material as shown in the third figure. Ultrasonic flaw detection is carried out by placing the sample on the top surface and scanning the surface to be tested. First, a couplant W such as water is sprinkled on the top surface of the material to be tested A, and the holder 1 is placed on top of it. In this state, the probe 1 protrudes from the bottom of the holder as shown in the second figure.
The probe surface 12 of o is in contact with the couplant W.

With the probe surface 12 in contact with the welding medium W as described above, when the holder 1 is moved over the test material A in the direction of the arrow X and the flaw detection surface of the test material A is scanned, the flaw detection surface of the test material A is scanned. The couplant W on the upper surface of the test material passes between the forward moving front wheels 6.7 provided on both sides of the bottom front end of the holder 1, as shown in FIG. The couplant W, which is provided at the center of the rear end of the bottom of the holder 1 and comes into contact with the moving rear wheel 8, is pushed toward the front probe surface 12 and collected by the moving rear wheel 8. Become.

Therefore, the state in which the couplant W is always present between the probe surface 12 and the flaw detection surface of the material under test A is maintained. In this way, the arrangement of each wheel 6.7.8 is such that the rear wheel 8 is
If the rear wheel 8 is provided as a front wheel at the center of the bottom front end of the holder 1, when the holder 1 moves forward, The couplant material W will be removed by the front wheel in the center, and if the rear wheels are also provided on both sides of the bottom of the holder in the same way as the front wheel 6.7, the couplant material W will pass between the front and rear wheels. The particles are no longer gathered toward the probe surface 12, and the desired result cannot be obtained.

In addition, when the holder 1 travels on the upper surface of the material to be tested in this way, each wheel 6, 7, 8 runs in contact with the upper surface of the material to be tested, so that the probe surface 12 of the probe 10 and The vehicle travels with the distance between the test material A and the flaw detection surface maintained at a constant distance.

In this way, the distance between the probe surface 12 and the flaw detection surface is maintained at a constant interval, and the state in which the couplant material W is always present is maintained and the flaw detection surface is scanned. The child 10 can output accurate detection signals.

Note that the operating rods are attached to both sides of the holder 1 using the shafts 15.
16 may be provided protrudingly, and the lower end of an operating rod 17 may be attached to this as shown in the third figure, and the holder 1 may be moved and scanned over the material A to be tested by holding this operating rod 17.

"Effects of the Invention" As mentioned above, the ultrasonic flaw detection method of the present invention maintains a constant distance between the probe surface of the probe and the flaw detection surface of the material under test by providing wheels at the bottom of the holder. In addition, when scanning the surface of the test material, the couplant is gathered below the probe surface, so that the space between the probe surface and the surface of the test material is kept as small as in the conventional method. The interval does not fluctuate, and the probe outputs accurate detection signals, improving flaw detection accuracy and stabilizing the quality of the material under test.

In addition, since no hoses are used to supply water, there is no need for hoses to wrap around and impair work efficiency as in the past, speeding up flaw detection and reducing labor costs. There is no restriction on the size of the plate, and it can be applied to any material to be tested, reducing the cost of flaw detection equipment.

[Brief explanation of the drawing]

Fig. 1 is a top view of the apparatus used in the method of the present invention, Fig. 2 is a front view of a part thereof, Fig. 3 is a usage state diagram, Fig. 4 is an explanatory diagram of the operation of the wheels, and Figs. FIG. 9 is a drawing showing a conventional example. 1: Holder 6.7.8: Wheel 10: Probe 12: Probe surface Patent applicant Furukawa Electric Co., Ltd. Representative Patent attorney Oka 1) Kikuji (and others 1)
Figure 5 Figure 6 Figure 7 Figure 8 Figure 9

Claims (1)

[Claims] The distance between the probe surface of the probe installed in the holder and the flaw detection surface of the test material is maintained at a very small distance, and a couplant is interposed between the probe surface and the flaw detection surface, and ultrasonic waves are applied. An ultrasonic flaw detection method characterized in that a wheel is provided at the bottom of the holder, and the couplant is moved below the probe surface by the wheel.