JPH02686Y2 - - Google Patents

Description

[Detailed description of the invention] This invention relates to the improvement of an ultrasonic probe for detecting defects on the inner and outer surfaces of steel pipes and the surface layer of round bars.

First, a conventional ultrasonic probe will be explained using FIG. 1.

Figure 1a is a cross-sectional view of a conventional ultrasonic probe.
FIG. b is a flaw detection waveform diagram using a conventional ultrasonic probe.

In Figures 1a and b, 1 is a vibrator, 2 is a wedge, and 3
is a case, 4 is a partition plate, 5 is a water reservoir section where the inside of the case 3 is divided by a partition plate 4, 6 is a reflection plate to confirm acoustic coupling, 7 is an ultrasonic beam, 8 is an air layer, 9 is water 10 is a water intake port, 11 is water,
Contact medium such as oil, 12 is the material to be inspected, 13 is the defect, 1
4 is a transmission pulse, 15 is a surface echo, 16 is a defect echo, 17 is a coupling echo, 18 is a flaw detection gate, θ ₁ is an angle provided for temperature compensation on the surface of the wedge 2 facing the test material 12, A is the surface of the wedge 2 facing the test material 12, and B is the surface of the wedge 2 that comes into contact with the water reservoir 5.

By the way, in an automatic ultrasonic flaw detection device, since the machine automatically processes all determinations of the presence or absence of defects and their size, the acoustic coupling state is checked to see if the ultrasonic waves are propagating normally to the test material 12. There is a need. For this purpose, a water reservoir 5 divided by a partition plate 4 is provided in the ultrasonic probe, and a reflecting plate 6 is further provided in the water reservoir 5.

To explain the propagation path of the ultrasonic beam in detail here, the ultrasonic wave emitted from the transducer 1 is input into the contact medium 11 via the wedge 2, reaches the surface of the test material 12, and is held at one point. The ultrasonic waves in the
The light propagates inside the oscillator 1 and returns to the oscillator 1 in the opposite direction due to a reflection source such as the defect 13.

In addition, some of the ultrasonic waves are reflected by the surface of the test material 12 and propagate toward the water reservoir 5 at the front of the probe, and then propagate to the wedge 2, the water reservoir 5, and the reflection plate 6. The ultrasonic waves reflected by the reflection plate 6 return to the transducer 1 via the opposite path.

In the conventional ultrasonic probe, the intake port 10 for the contact medium 11 into the water reservoir 5 is provided on the front surface of the case 3, and the temperature changes on the surface A of the wedge 2 facing the test material 12. An angle θ ₁ is provided that reduces the change in the refraction angle of the ultrasonic wave in the specimen 12 even if
Furthermore, the surface B of the wedge 2 that comes into contact with the water reservoir is also parallel to the surface A in order to eliminate imaginary echoes due to ultrasonic waves in the transverse wave mode. Therefore, there is a portion in the water reservoir 5 that is lower in height than the water intake port 10, and the air layer 8 tends to accumulate in this portion. Since the contact medium 11 entering from the water intake port 10 flows to the water intake port 9 along the surface of the reflecting plate 6, the air layer 8 once accumulated cannot be easily removed. As a result, the ultrasonic beam 7 cannot reach the water reservoir 5 and the reflection plate 6 and is reflected between the A side and the B side of the wedge 2, resulting in a coupling echo 17 for checking the acoustic coupling state. Even if the defect echo 16 appears within the flaw detection gate 18, it becomes impossible to judge whether or not it is correct information, and the reliability of the ultrasonic automatic flaw detection system becomes extremely low.

This invention significantly improves these conventional drawbacks and provides an ultrasonic probe that can confirm a stable acoustic coupling state.

An embodiment of this invention will be described below in detail with reference to FIG.

FIG. 2a is a sectional view of the ultrasonic probe according to this invention, and FIG. 2b is a flaw detection waveform diagram when using the ultrasonic probe according to this invention.

In Figures 2a and b, 1 is a vibrator, 2 is a wedge, and 3
is a case, 4a is a first partition plate, 4b is a second partition plate, 5 is a water reservoir, 6 is a reflection plate, 7 is an ultrasonic beam, 9 is a water outlet, 10 is a water intake port, 11 is a water , a contact medium such as oil, 12 is the material to be inspected, 13 is a defect, 14 is a transmitted pulse, 15 is a surface echo, 16
is a defective echo, 17 is a coupling echo, 18
19 is a flaw detection gate, and 19 is a first partition plate 4a and a second
θ ₁ is the angle provided for temperature compensation on the surface of the wedge 2 facing the test material 12 , and A is the angle of the wedge 2 facing the test material 12 . The surface B is the surface of the wedge 2 that comes into contact with the water reservoir 5, 19 is a flow path provided in the water reservoir 5, and 20 is the lowest water level in the water reservoir 5.

In the ultrasonic probe according to this invention, in addition to the water outlet 9 provided along the reflection plate 6, a second partition plate 4b and a flow path 19 are provided in the water reservoir 5. The contact medium 11 that has entered the water reservoir 5 from the water intake port 10 once collides with the second partition plate 4b, and flows therein in the direction of the water intake port 9 and in the direction of the surface B of the wedge 2, and flows into the water reservoir 5. Lowest water level part 20 and flow path 19
Since the air layer that tends to stagnate at the lowest water level part 20 in the water reservoir 5 flows out from the ultrasonic probe through the flow path 19 along with the flow of the coupling medium 11, The surface B of the wedge 2 that is pushed out of the tentacle and comes into contact with the water reservoir 5 is always filled with the contact medium 11 without any air layer. Therefore, the ultrasonic beam 7 passes through the wedge 2, reaches the reflection plate 6, returns to the transducer 1 via the surface of the test material 12, is received as a coupling echo 17, and the acoustic coupling can be confirmed. Ru.

Note that the cross-sectional area of the flow path 19 must be larger than the cross-sectional area of the water outlet 9 to increase the amount of the contact medium 11 flowing out of the ultrasonic probe via the flow path 19. Needless to say.

As mentioned above, this idea provides a flow path through which the contact medium flows to the outside of the ultrasonic probe via the lowest water level of the water reservoir, and the cross-sectional area of the flow path is By making the cross-sectional area larger than the extraction port, a practical ultrasonic probe is provided that allows stable acoustic coupling to be confirmed.

[Brief explanation of drawings]

1A and 1B are a sectional view and a flaw detection waveform diagram of a conventional ultrasonic probe, and FIGS. 2A and 2B are a sectional view and a flaw detection waveform diagram of an ultrasonic probe according to this invention. In the figure, 1 is a vibrator, 2 is a wedge, 3 is a case,
4a is a first partition plate, 4b is a second partition plate,
5 is a water reservoir, 6 is a reflection plate, 7 is an ultrasonic beam, 8
is an air layer, 9 is a water intake port, 10 is a water intake port, 11
is a contact medium, 12 is a test material, 13 is a defect, 14 is a transmitted pulse, 15 is a surface echo, 16 is a defect echo, 17 is a coupling echo, 18 is a flaw detection gate, 19 is a flow path, and 20 is the lowest water level part It is. still,
Identical or equivalent parts in the figures are designated by the same reference numerals.

Claims (1)

[Scope of utility model registration request] An ultrasonic probe that performs ultrasonic flaw detection by providing a gap between the material being tested and the ultrasonic probe, and filling the gap with a liquid contact medium such as water or oil, transmits and receives ultrasonic waves. a vibrator, a wedge for fixing the vibrator at a predetermined angle with respect to the surface of the test material, and a case for protecting the vibrator and fixing the wedge;
a first barrier plate that prevents water from entering the vibrator; a water reservoir surrounded by the wedge, the case, and the first barrier plate; a reflector provided in the water reservoir; a water intake port connected to the water reservoir provided on one side of the case that contacts the water reservoir; and a water intake port connected to the water reservoir;
a second barrier plate having a length such that a contact medium flows through the lowest water level in the water reservoir between the barrier plate and the reflecting plate; and the first barrier plate and the second barrier plate. An ultrasonic probe characterized by having a flow path through which a contact medium flows between the probe and the probe.