JPH09251012A - Rotating tire type ultrasonic probe - Google Patents

Abstract

(57) [Abstract] [PROBLEMS] To provide a rotating tire type ultrasonic probe used in an ultrasonic flaw detection test for detecting internal flaws such as a steel plate and a welded portion. SOLUTION: A lower end of an ultrasonic probe 4 is rotatably supported by a bracket 25 at a position near a contact surface between a tire 2 and a material to be inspected 1 and an angle variable knob is rotated. The incident angle θ _i of the ultrasonic beam is made adjustable by using a pinion gear 21 and a rack 22 attached to the work shaft 5.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotating tire type ultrasonic probe, and more particularly to a rotating tire type ultrasonic probe used in an ultrasonic flaw detection test for detecting internal flaws such as steel plates and welded portions. .

[0002]

2. Description of the Related Art In general, in order to detect internal flaws in a steel sheet and flaws on the surface of a rolling roll, flaw detection is performed using a rotating tire type ultrasonic probe. Mainly, in the case of the former steel plate, the plate wave ultrasonic waves are emitted in the direction perpendicular to the tire rotation direction, and in the case of the latter rolling roll, the surface wave ultrasonic waves are emitted in the tire rotation direction, and the reflection signal from the flaw is generated. The presence or absence of a flaw is detected by receiving the. In addition, transverse ultrasonic waves are used for ultrasonic flaw detection of a welded portion, and flaw detection is performed by emitting ultrasonic waves in the tire rotation direction.

Since the above-mentioned plate wave flaw detection has various modes due to the characteristics of the plate wave, conventionally, flaw detection by changing the incident angle of ultrasonic waves has been performed. However, in surface wave flaw detection or oblique angle flaw detection that emits ultrasonic waves in the rotation direction, flaw detection with a fixed angle is performed. The flaw detection performance in such ultrasonic flaw detection depends on the surface of the flaw and the direction of incidence of the ultrasonic beam, and the detection performance is higher when the flaw is at a right angle. Therefore, depending on the flaw or the like to be detected, the incident angle, that is, the refraction angle may be changed to perform flaw detection. The angle of incidence of ultrasonic waves into the tire and the angle of refraction of the material to be inspected are refracted according to Snell's law.

In an ultrasonic flaw detection test of a steel plate or a welded portion, particularly a bevel angle flaw detection test of a welded portion, the flaw detection performance greatly changes depending on the angle of the ultrasonic wave incident on the flaw. Therefore, easily changing the refraction angle in oblique flaw detection is a useful technique for improving the effect of detecting flaws. At this time, if the point of incidence of the ultrasonic waves is clear, the position of the flaw can be known accurately.

An example of this is shown in FIGS. 3 and 4, in which 1 is a material to be inspected, 2 is a tire which rotates in contact with the material to be inspected 1, 3 is water filled in the tire 2, etc. Is the medium of. Reference numeral 4 denotes an ultrasonic probe, which is a slit portion 6a of a probe fixing arm 6 rotatably fixed to an angle changing shaft 5.
It is attached to and fixed with bolts 7. Bearings 8a and 8b are provided in the center of the tire 2, and one bearing 8a
A tire rotation shaft 10 that supports the angle varying shaft 5 via a bearing 9 is axially supported inside, and a tire holding support leg 11a is supported outside thereof. The other bearing 8b has a hollow shaft 12 for rotating a tire that holds a supporting leg 11b for holding a tire.
Is supported. Inside the hollow shaft 12 for rotating the tire, one end is connected to the probe fixing arm 6 and the other end is connected to the angle adjusting knob 13.
Is rotatably attached.

In the rotating tire type ultrasonic probe constructed as described above, when the material to be inspected 1 such as a steel plate is flaw-detected, the refraction angle θ _{r of the} ultrasonic beam UB to the material to be inspected 1 is always constant. The angle of incidence θ _i is fixed in advance by adjusting the angle adjusting knob 13 so as to be used. The reason is that the detection performance of a flaw (not shown) such as a welded portion is improved if the angle formed by the surface of the flaw and the angle at which the ultrasonic beam UB is incident on the flaw are as perpendicular as possible, This is because the angle is set to one that is considered to have the highest detection performance.

[0007]

However, in the conventional rotary tire type ultrasonic probe as shown in FIGS. 3 and 4, the angle adjusting knob 13 is used to make the ultrasonic probe 4 incident. When the angle θ _i is changed, the position of the incident point is largely deviated, and the refraction angle θ _r is changed by the change of the incident angle θ _i. It is difficult to estimate the position. Further, if the incident angle θ _{i is} to be changed largely, the ultrasonic beam UB is deviated from the contact surface between the tire 2 and the material 1 to be inspected, and ultrasonic flaw detection may be impossible in some cases.

Further, as shown in FIG. 5, when estimating the position of the defect F existing at the depth of d from the surface of the material to be inspected 1,
Beam path W of ultrasonic waves and refraction angle θ obtained from the flaw detection screen
_{Using r} and the distance Y from the incident point position A to the defect F, the relations of trigonometric functions are used to calculate by the following equations (1) and (2). d = W ・ cos θ _r ………… (1) Y = W ・ sin θ _r ………… (2) At this time, the deviation Δ of the incident point position A from the reference point B is unclear. Therefore, it is difficult to estimate the defect position. In addition, ultrasonic waves are incident from a portion where the contact between the tire and the test material is unstable, and the flaw detection becomes unstable.

An object of the present invention is to provide a rotary tire type ultrasonic probe which solves the problems of the prior art as described above.

[0010]

In order to solve the above-mentioned problems, the present invention provides a rotary tire type ultrasonic wave incorporating an ultrasonic probe for detecting internal flaws in a material to be inspected such as a steel plate and a welded portion. In the probe, a lower end portion of the ultrasonic probe is rotatably supported by a support member at a position close to a contact surface between a tire and a test material, and an angle adjusting knob is used for changing an angle. It is characterized in that the incident angle of the ultrasonic beam can be adjusted by using a rotational force transmitting means attached to the shaft.
Incidentally, it is preferable that the rotational force transmitting means is a combination of a pinion gear and a rack.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a side sectional view showing an embodiment of the present invention, and FIG.
It is arrow sectional drawing. In these drawings, the same members as those of the conventional example are designated by the same reference numerals and the description thereof will be omitted.

As shown in these figures, the ultrasonic probe 4
A support metal fitting 20 is mounted on the body of the device, and the support metal fitting 20 is rotatably held via a pin 23 on a rack 22 screwed to a pinion gear 21 attached to the angle varying shaft 5. A fixing metal fitting 24 is attached to the lower end of the body of the ultrasonic probe 4, one end of which is fixed to the tire rotating hollow shaft 12, and the contact surface between the tire 2 and the material to be inspected 1 is pressed as much as possible. It is supported by a bracket 25, which is located close to it, via a pin 26 so that it can swing freely.

By supporting the ultrasonic probe 4 in this manner, the rotation of the angle adjusting knob 13 is rotated by the pinion gear.
Since the pin 26 can be transmitted to the rack 22 via 21 and can be rotated at a position close to the contact surface with the pin 26 as the center of rotation, that is, the fulcrum, the ultrasonic beam UB emitted from the ultrasonic probe 4 is transmitted.
The incident angle θ _i can be changed, the amount of fluctuation of the incident point position can be suppressed even when the ultrasonic probe is rotated, the defect position can be easily estimated, and flaw detection can be stabilized.

In the above embodiment, the pinion gear 21 and the rack 22 are used to adjust the angle of the ultrasonic probe 4, but the present invention is not limited to this.
For example, any mechanism such as a link mechanism may be used as long as it is a rotational force transmitting means capable of replacing a rotational moment with a change in angle.

[0015]

[Examples] Using the rotating tire type ultrasonic probe of the present invention, internal flaws in a steel sheet were detected. At this time, when the distance between the center of the tire and the contact surface was 90 mm and the distance between the center of rotation of the ultrasonic probe and the contact surface was 20 mm, the flaw refraction angle θ _r was 45 ° to 70 °. Even if it was changed to, the fluctuation of the position of the incident point of the ultrasonic beam was only within 3 mm. on the other hand,
In the conventional example, it is known that a deviation of about 11 mm usually occurs, so it can be seen that the present invention is excellent.

[0016]

As described above, according to the present invention,
Since the center of rotation of the ultrasonic probe is set as close to the contact surface as possible, the deviation of the incident point is reduced, which
The effect that the defect position can be easily estimated, the detection sensitivity can be enhanced, and stable flaw detection can be performed is obtained.

[Brief description of drawings]

FIG. 1 is a side sectional view showing an embodiment of the present invention.

FIG. 2 is a sectional view taken along the line AA of FIG.

FIG. 3 is a side sectional view showing a conventional example.

FIG. 4 is a sectional view taken along line XX of FIG.

FIG. 5 is an explanatory diagram of problems in the conventional example.

[Explanation of symbols]

 1 Test Material 2 Tire 3 Medium (Water) 4 Ultrasonic Probe 5 Angle Adjusting Shaft 8a, 8b Bearing 10 Tire Rotating Shaft 11a, 11b Tire Holding Shaft 12 Tire Rotating Hollow Shaft 13 Angle Adjusting Knob 14 Shaft for variable angle 20 Support bracket 21 Pinion gear (rotational force transmission means) 22 Rack (rotational force transmission means) 23, 26 pin 24 Fixing bracket 25 Bracket (supporting member) F Defective

Claims (2)

[Claims] 1. A rotary tire type ultrasonic probe having an ultrasonic probe for detecting internal flaws in a material to be inspected such as a steel plate or a welded part, wherein a lower end portion of the ultrasonic probe is a tire. The incident angle of the ultrasonic beam is rotatably supported by a support member at a position close to the contact surface with the material to be inspected, and the rotational force transmission means attached to the angle varying shaft rotated by the angle adjusting knob. A rotary tire type ultrasonic probe characterized by being adjustable. 2. The rotating tire type ultrasonic probe according to claim 1, wherein the rotational force transmitting means is a combination of a pinion gear and a rack.