JP3023642B2 - Insertion depth measurement method for welded pipe joints - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for measuring the insertion depth of a welded pipe joint, and more particularly to a welded pipe joint which is safe and easy to manage, and which can be used at low cost. The present invention relates to a method for measuring the insertion depth.

[0002]

2. Description of the Related Art When welding a pipe to an insertion welding type coupling or the like, a gap of 1 to 3 mm is defined between the end face of the pipe insertion part such as the coupling and the end face of the inserted pipe. Must be provided. This is because if there is no gap or if the gap is small, the pipe will expand due to heat input from welding and residual stress will be generated in the member, defects will easily occur in the welding root part, and if the gap is too large, the strength of the welded joint will decrease. Because it will. Therefore, an inspection is performed to determine whether a prescribed gap is formed after welding, and an X-ray inspection method is conventionally known as this inspection method.

[0003]

However, the above-mentioned conventional X-ray inspection method requires an X-ray inspection apparatus which is expensive and requires careful handling. Could not be used. The present invention has been made in view of the above circumstances, and provides a method for measuring the insertion depth of a welded pipe joint that is safe, easy to manage, and cost-effective, and is lightweight and easy to use. With the goal.

[0004]

According to the present invention, there is provided a semiconductor device comprising:
Insertion depth measurement method in the described welded pipe joint,
A transmitting unit with a transmitting oscillator attached to the transmitting wedge is provided on the front side in the flaw detection direction, and a receiving unit with a receiving oscillator parallel to the transmitting oscillator attached to the receiving wedge is provided on the rear side in the flaw detecting direction. A method for measuring an insertion depth in a welded pipe joint using an oblique probe including a sound absorbing material separating a transmitting unit and the receiving unit and a casing accommodating them, comprising: A transverse wave of ultrasonic waves is emitted toward the end face of the pipe on the welding side at a refraction angle of 75 to 80 degrees, and a reflected echo reflected on the end face on the welding side after one or two or more reflections avoiding the welded portion, Further, after one or more reflections, the signal is received by a receiving vibrator attached to the receiving side wedge arranged behind the transmitting side wedge, and the propagation time of the ultrasonic wave is determined by the propagation time from transmission to reception of the ultrasonic wave. Insertion depth To measure.

[0005]

According to the first aspect of the present invention, there is provided a method for measuring an insertion depth in a welded pipe joint.
Ultrasonic waves are emitted at 5 to 80 degrees toward the end face of the pipe on the welding side. The transverse wave incident into the pipe is reflected at the end face of the pipe on the welding side, avoiding the weld, and the reflected echo is reflected by the receiving oscillator disposed behind the transmitting oscillator after being reflected one or more times. The insertion depth of the pipe can be measured by calculating from the propagation time from transmission to reception of the shear wave. In addition, since the reflected echo of the transverse wave from the transmitting oscillator arranged in the front part is received by the receiving oscillator arranged in the rear part, even if the pipe has a small radius of curvature, the transmitting side wedge and the receiving part are received. The measurement can be performed by directly contacting the central portion of the side wedge with the pipe, thereby improving the measurement sensitivity.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments embodying the present invention will now be described with reference to the accompanying drawings to provide an understanding of the present invention. Here, FIG. 1 is an enlarged sectional view showing a use state of the oblique probe for measuring the insertion depth in the welded pipe joint according to one embodiment of the present invention.

As shown in FIG. 1, a bevel probe 10 for measuring the insertion depth in a welded pipe joint used in one embodiment of the present invention is disposed at the front of the bevel probe 10. A transmission unit 13 having a transmission wedge 11 for generating an ultrasonic wave attached to the transmission wedge 11 and a transmission wedge 14 disposed at the rear of the oblique probe 10 and attached to the reception wedge 14.
A receiving section 16 on which a flat-plate receiving vibrator 15 parallel to the above is mounted, a sound absorbing material 17 which inclines diagonally forward and downward to partition the transmitting section 13 and the receiving section 16, and a stainless steel casing 18 for accommodating them. Have.

The transmitting wedge 11 and the receiving wedge 14 are made of, for example, a synthetic resin such as an acrylic resin. The transmitting wedges 11 and 14 are respectively provided on the rear inclined surfaces 11a and 14a which are inclined downward. The element 12 and the receiving vibrator 15 are attached. The transmitting vibrator 12 and the receiving vibrator 15 are well-known vibrators in which electrodes are fixed to both surfaces of a vibrating plate made of, for example, lead zircon titanate. Further, the lower surfaces of the transmission-side wedge 11 and the reception-side wedge 14 are flat surfaces, but are not limited thereto, and may be curved surfaces along the outer peripheral surface of the pipe 19, for example.

The rear inclined surface 11 of the transmitting side wedge 11
The inclination angle of “a” is set so that the transverse wave of the ultrasonic wave emitted from the transmitting transducer 12 propagates in the pipe 19 at an angle θ (θ = 75 to 80 degrees). The inclination angle of the inclined surface 14a is also set so that the reflection echo capturing angle becomes the same angle θ.

Next, a method of measuring the insertion depth in a welded pipe joint according to an embodiment of the present invention using the angle probe 10 will be described. In the embodiment, the coupling 20 is adopted as a welded pipe joint to which the pipe 19 is welded. As shown in FIG.
When measuring the insertion depth at the welded portion 21 with 0, a couplant such as grease is applied to the end of the pipe 19 on the welded portion 21 side, and the lower surface of the bevel probe 10 is applied to this applied portion. The insertion depth of the pipe 19 is measured while applying.

That is, ultrasonic waves are periodically generated from the transmitting oscillator 12 to which the pulse voltage is applied, and only the transverse waves of the ultrasonic waves pass through the transmitting wedge 11 and enter the pipe 19 at the incident angle θ. The light propagates toward the end face of the pipe 19 on the welding side. As a result, high-precision measurement using only the transverse wave can be performed.

As shown by the solid line in FIG. 1, the transverse wave incident into the pipe 19 reflects inside the
And is reflected at the end face of the pipe 19 on the welding side. Then
The reflected echo is reflected a plurality of times inside the distal end of the pipe 19 similarly avoiding the welded portion 21 as shown by the broken line in FIG.
Receiving section 16 arranged on the back of transmitting section 13 from the outer peripheral surface of
Is received at an angle θ in the receiving side wedge 14 and vibrates the receiving vibrator 15. As described above, since the reflected echo of the transverse wave emitted from the transmitting oscillator 12 disposed on the front side is received by the receiving oscillator 15 disposed on the rear side, the transmitting wedge 11 and the receiving wedge 1 are received.
4 can be measured by directly contacting the central portion of the pipe 19 with the pipe 19, thereby improving the measurement sensitivity.

Thereafter, a computer (not shown) measures the distance a from the probe 10 to the end face of the pipe 19 based on the time from transmission to reception of the shear wave, and further subtracts the width b of the welded part to obtain the pipe 19. Is calculated.

As described above, instead of the expensive X-ray inspection apparatus which is conventionally used for measuring the insertion depth of the pipe and requires careful handling and management, the angle beam probe 10 is used.
By adopting the inspection apparatus having the above, the safety and ease of management can be improved, and the cost of the entire apparatus can be reduced. Also,
The conventional X-ray inspection apparatus is large and difficult to move, but the apparatus employing the angle beam probe 10 of the embodiment is compact and lightweight, so that it can be moved anywhere and used easily. Although the embodiment of the present invention has been described above, the present invention is not limited to this embodiment, and any change in design without departing from the scope of the present invention is included in the present invention.

[0015]

The method for measuring the insertion depth of a welded pipe joint according to the first aspect of the present invention measures the length of the end of a pipe inserted into the welded pipe joint using ultrasonic waves. As a result, safety is high, handling and management are not required to be very careful, and the price is low and cost can be reduced. In addition, the shape is compact and lightweight,
It can be moved anywhere and used easily. In addition, since the transmitting transducer is located at the front of the bevel probe and the receiving transducer is located at the rear, the central part of the transmitting wedge and the central part of the receiving wedge can be directly contacted with the pipe for measurement, thereby increasing the measurement sensitivity. Can be improved.

[Brief description of the drawings]

FIG. 1 is an enlarged sectional view showing a use state of an oblique probe used in an embodiment of the present invention.

[Explanation of symbols]

10: oblique probe, 11: transmission side wedge, 11a: rear inclined plane, 12: transmission oscillator, 13: transmission unit, 14: reception side wedge, 14a: rear inclined plane, 15: reception oscillator, 1
6: Receiver, 17: Sound absorbing material, 18: Casing, 19:
Piping, 20: coupling, 21: weld

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Kenji Tanaka 4-10-13 Ibori, Kokurakita-ku, Kitakyushu-shi, Fukuoka Prefecture Inside New Japan Non-Destructive Inspection Co., Ltd. (72) Inventor Kunichi Watanabe Isogo-ku, Yokohama-shi, Kanagawa 8 Shin-Sugita-cho Toshiba Corporation Yokohama Office (72) Inventor Kunio Kawamata 3-7-1 Nishi-Shimbashi, Minato-ku, Tokyo Toshiba Plant Construction Corporation (56) References JP-A-55-60812 (JP, A) JP-A-6-317567 (JP, A) JP-A-3-80362 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) G01N 29/00-29/28 G01B 17 / 00

Claims (1)

(57) [Claims] 1. A transmission unit having a transmission wedge attached to a transmission side wedge is provided on the front side in the flaw detection direction, and a reception unit having a reception side wedge provided with a reception vibrator parallel to the transmission vibrator is provided on the rear side in the flaw detection direction. A method for measuring an insertion depth in a welded pipe joint using an oblique probe, further comprising: a sound absorbing material separating the transmitting unit and the receiving unit; and a casing accommodating the sound absorbing material. A transverse wave of an ultrasonic wave is emitted from the probe at an oblique refraction angle of 75 to 80 degrees toward the end face of the pipe on the welding side, and is reflected at the end face on the welding side after one or more times of reflection avoiding the welded portion. The reflected echo is received by a receiving vibrator attached to the receiving side wedge disposed behind the transmitting side wedge after one or more reflections, and propagated from transmission to reception of the ultrasonic wave. Depending on the time Insertion depth measuring method in the weld type pipe joint and measuring the insertion depth.