JPH0513464B2 - - Google Patents

Description

[Detailed Description of the Invention] [Field of Application of the Invention] The present invention uses a liquid immersion method in which a probe and a specimen are immersed in a liquid such as water or oil to detect internal defects, thickness, and sound velocity of a specimen. Regarding a positioning device for a test object when performing measurements such as the above, this positioning system is particularly suitable for automatically positioning the beam axis of the ultrasonic waves emitted from the probe and the test surface of the test object so that they are perpendicularly opposed to each other. Regarding equipment.

[Background of the invention]

Detection of internal defects in a test object, measurement of the test object's thickness, sound velocity, etc. are often performed using a liquid immersion method (the water immersion method is common and will be described below as the water immersion method).
This is because there is no direct contact between the probe and the object to be tested, so it has the advantage that ultrasonic waves can be transmitted and received stably without being affected by the thickness of the couplant oil film or the roughness of the testing surface. Due to this advantage, it is widely used for automatic flaw detection purposes. However, the water immersion method is a method in which the ultrasonic waves emitted from the probe are propagated through water over a certain distance before being incident on the subject, so the ultrasonic waves are reflected at the interface between the water and the subject. The refraction is different from that of the direct probe method because it involves water (it is almost the same when other liquids are involved). For example, when examining steel materials using longitudinal waves, the relationship between the angle of incidence θi and the angle of refraction θr when ultrasonic waves are incident on steel from water is that the angle of refraction θr is approximately four times the angle of incidence θi. , and for angle angle flaw detection, the incident angle is 14.5°~
It is known that refracted transverse waves of 33° to 90° can be obtained within the range of 27.3°, and compared to direct contact angle angle probes using organic glass, the incident angle range is smaller and the angle of incidence is that much more subtle. angle adjustment is required. For this reason, in the case of vertical flaw detection, it is necessary to point the probe correctly perpendicular to the test object, and in the case of angle flaw detection, it is necessary to orient the probe correctly to the test object in order to make the delicate angle adjustment. It is necessary to correctly orient the probe perpendicularly to the surface and to maintain a constant distance between the probe and the flaw detection surface.

Conventionally, the method used to address the above-mentioned needs is to transport a sample held by a transport means such as a robot installed outside the tank to a probe holder with a probe installed inside the tank. were carried into opposing positions by the carrying means and placed in opposition.
A common method of vertically opposing the probe and the test object is to place the test surface of the test object vertically opposite the probe when the carrying means grabs the test object. This was done by adjusting and arranging them so that the This method is used for automatic flaw detection of a large number of test objects, but it is difficult to set the set position of a large number of test objects without error even if a jig is used. Even if the setting is possible, errors in the relative positions of each part of the loading means, the installation position of the probe holder, the mounting position of the probe, and the position of the water tank itself will accumulate, and it will be difficult to handle a large number of specimens. The reality is that it is difficult to correctly orient the probe perpendicularly to the probe each time, and measurement errors often occur. Detecting the occurrence of measurement errors is also increasingly difficult because measurements are normally performed on the assumption that the set position of the subject is correct.
For its detection, measurements may even be performed more than once. Further, there were many problems such as the need for delicate adjustments in adjusting the set position.

[Purpose of the invention]

The present invention solves the problems of the prior art, and even when the test object is carried into the probe holder, even if the test surface of the test object is not correctly perpendicularly opposed to the probe, It is an object of the present invention to provide a positioning device for a subject in an ultrasonic examination, which can automatically position the subject in a vertically opposed position when carrying the subject is finished and measurement is started.

[Summary of the invention]

The present invention provides a positioning device for a subject, which includes a pair of opposing probe holders having clamping surfaces that clamp the subject, and a probe holder that is perpendicular to the clamping surface of the probe holder and that has a clamping surface that clamps the specimen. A guide member slidably supports the gap between the opposing clamping surfaces in the opening/closing direction, and the gap between the opposing clamping surfaces is adjusted while the subject being carried into the gap slides along the guide member. When the probe holder is expanded, it generates a force acting on the clamping surface of the probe holder in the direction of clamping the subject in opposition to the expanding force, and is provided to expand and contract along the guide member. By comprising a tabular spring and a stand that supports both ends of the guide member so as to be movable together with the clamped test object, the probe holder, the guide member, and the spring, the flaw detection surface of the test object can be fixed. This positioning device is designed to automatically position the probe at a position where it is correctly perpendicularly opposed to it during measurement even if the probe is brought in in a state where it is not correctly perpendicularly opposed to it.

[Embodiments of the invention]

Embodiments of the present invention will be explained with reference to FIGS. 1 to 5. Figures 1 and 2 are explanatory diagrams of the first embodiment. In this embodiment, a flat plate specimen whose flaw detection surface and bottom surface are parallel is measured in a liquid tank using two probes to measure sound velocity, thickness, etc. Indicates when to do this. In the figure, reference numeral 1 denotes a probe holder, which has a clamping surface 1a for clamping a subject M, and a pair of probe holders facing each other constitutes a set. A pair of transmitting probes 2 and receiving probes 3 are attached to the upper part, and two penetrating holes 1b are bored in parallel in the lower part in a direction perpendicular to the clamping surface 1a. .
When the probes 2 and 3 are vertical probes, the clamping surface 1a is parallel to the plane of the vibrator. Also, the pinching surface 1
The upper part of a is appropriately rounded so that the subject M can be easily inserted.
Or chamfer. A rod-shaped guide member 4 is inserted into the hole 1b of the probe holder 1 with little play. The probe holder 1 is supported on two guide members 4 so as to be slidable in the direction in which the gap between the opposing clamping surfaces 1a opens and closes. Spring seats 4a are fixed to both ends of the guide member 4, and a spring 5 is fitted between the spring seats 4a and the surface 1c of the probe holder 1 opposite to the clamping surface 1a. The above configuration has a spring seat 4 on a stand 6.
It is supported so as to be movable integrally with the subject via a.

The subject M is grabbed by a carrying means (not shown) and carried into the liquid tank, and then the grabbed subject M is usually inserted between the opposing clamping surfaces 1a to be held by the probe holder 1 from above. . In this case, the initial distance between the opposing clamping surfaces 1a may be zero depending on the thickness and weight of the subject M, and is arbitrarily determined. The desired flaw detection surface of the object M is the probes 2 and 3.
The probe holder 1 is inserted with the gap between the clamping surfaces 1a expanded to the position where the probe holder 1 is attached. At this time, the probe holder 1 slides on the guide member 4 while pressing the spring 5, and the gap between the clamping surfaces 1a is expanded. The spring 5 generates a force that opposes the applied force, and the subject M is held between the holding surfaces 1a by the compressive force of the spring. Measurement starts in this state, but whether or not the test surface of the test object M is correctly perpendicularly opposed to the probes 2 and 3 must be checked before measuring a large number of test objects M. A test is performed on the subject M, and the waveforms or echo patterns in a correct state and an incorrect state can be compared and determined visually or on a monitor. When the waveform or echo pattern is incorrect, that is, when the subject M is inserted between the clamping surfaces 1a in the tilted state shown in FIG. , the guide member 4 and the spring 5 are integrally lifted to such an extent that the spring seat 4a is slightly separated from the base 6. Then, since the clamping surface 1a is pressed against the subject M by the spring 5, it automatically clamps both sides of the tilted subject M, bringing them into a stable state of close contact. This close contact state is a state in which both surfaces of the subject M and the probes 2 and 3 are correctly positioned to face each other vertically, and deformation of the waveform or echo pattern due to the incorrect facing state is determined by visual inspection or monitor. In this case, the correct facing state can be obtained very easily and automatically by simply lifting the subject M slightly. In addition, when the object M is a flat plate having two parallel surfaces as in this embodiment, the two parallel surfaces and the probes 2 and 3 are not only perpendicularly opposed to each other but also automatically and equally spaced. It also has an effect that can be measured by distance. In addition, the clamping surface 1a is a flat surface that comes into close contact with two parallel surfaces of the subject M. However, if the clamping surface of the subject M is a tapered surface, the clamping surface 1a should also be a tapered surface that matches the tapered surface. It may be a surface, and it may be a surface that matches the surface of the subject M to be squeezed. Spring 5 pushes surface 1c so as to press surface 1c.
A compression spring is provided between the spring seat 4a and the spring seat 4a, but instead of the compression spring, a tension spring is provided between the opposing probe holders 1, and the tension spring and the probe holder are locked, so that the clamping surface The subject M may be held with a force that suppresses the force when the interval 1a is expanded. Although two springs 5 are provided for each guide member 4, one may be omitted and only one spring may be used. Next, the position where the guide member 4 is provided is shown as being inserted into the lower part of the probe holder 1 in this embodiment.
Any other position may be used as long as it is within the height range of the clamping surface 1a. Further, although probes are attached to each probe holder 1, it is also possible to eliminate one probe and use one probe for both transmitting and receiving purposes. When the measurement is completed and the subject M is lifted, the probe holder 1 and the guide member 4 are also lifted up at the same time since they are integrally formed by the spring 5. However, spring seat 4
a hits the table 6 and is prevented from being lifted, and the subject M separates from the clamping surface 1a against the compressive force of the spring 5. The positioning device from which the subject M has left is
The state is restored to automatically position the object M to be measured next, and the above operation is repeated to continue measurement at the correct position.

Next, a second embodiment will be explained with reference to FIGS. 3 to 5. In the figures, the same reference numerals as in FIGS. 1 and 2 indicate the same things. This example is also the first
As in the embodiment described above, a case is shown in which a flat plate object in which the flaw detection surface and the bottom surface are parallel is measured in a liquid tank using two probes. In the figure, reference numeral 14 denotes a guide member, in the center of which a fulcrum pin 7 is provided, which is supported on a stand 8 so as to be able to freely swing around the fulcrum pin 7 together with a pair of probe holders 1 inserted therein. There is. Spring seat 4a
An eye end 9 having an elongated hole is fixed to the outer surface of the eye end 9, and the elongated hole loosely fits into a bar 10 which is fixed upright to the base 8. Eye end 9 for bar 10
A spring 11 is fitted between the fulcrum pin 7 and the stand 8.
It is designed to support the unbalanced load that occurs on the left and right sides. 12 is a stopper for the eye end 9 to come off.

When the subject M is grabbed by the carrying means and carried so as to correctly face the probe in the liquid tank perpendicularly, the explanation is the same as in the first embodiment. However, when the subject M is inserted between the clamping surfaces 1a in an inclined state as shown in FIG. It will work with care. At this time, since the guide member 14 can freely swing around the fulcrum pin 7 together with the probe holder 1, it swings to an angle corresponding to the inclination of the subject M. In the swinging guide member 14, the elongated holes in the eye ends 9 at both ends are connected to the bar 10.
and is guided in the swinging direction. When the subject M is inserted to a predetermined position on the clamping surface 1a, the swinging stops. The unbalance of the load caused by the eccentricity occurring on the left and right sides of the fulcrum pin 7 during rocking is counteracted by the spring 11 on one side being compressed and the spring 11 on the other side being stretched.
When the swinging is stopped, the swinging posture shown in FIG. 5 corresponding to the inclination angle of the subject M is maintained as it is. In this swinging posture, when the subject M is inserted between the clamping surfaces 1a in an inclined state in the first embodiment, the carrying means moves the spring seat 4a slightly away from the table 6 so that the subject M This is the same state as when the object M is lifted up, and is nothing but a state in which both surfaces of the subject M and the probes 2 and 3 are correctly positioned vertically opposing each other. Therefore, in this embodiment, it is not necessary to visually or monitor to determine whether the waveform or echo pattern of the incorrect facing state has been deformed, and the correct facing state can always be automatically obtained simply by carrying it in. When the measurement is completed in the swung posture shown in FIG. 5, the subject M is carried out from the probe holder 1 by the carry-in means, and at the same time, the shortened spring 11 is extended and vice versa. The tabular spring 11 is compressed and returns to the horizontal state. Even if the next subject M to be measured is brought in in the incorrect facing state, it is automatically positioned in the correct facing state.

Also in this example, as explained in the first example,
If the object M is a flat plate with two parallel surfaces, it is possible to always measure the same distance automatically, and the clamping surface 1a
The shape of the guide member 14 (first implementation In the example, the position of 4) can be changed, and it can also be applied to the one-probe method.
Of course, in the second embodiment, similar positioning can be performed not only when using a vertical probe but also when using an oblique probe.

〔Effect of the invention〕

As explained above, in the present invention, even if the test surface of the test object is not correctly perpendicularly opposed to the probe when it is carried in, it will automatically be correctly corrected when it is inserted into the probe holder and measured. It has excellent effects when positioned in vertically opposed positions.

[Brief explanation of the drawing]

All drawings are explanatory diagrams of embodiments of the present invention, and the first
The figure is a side view illustrating the first embodiment, FIG. 2 is a view taken in the direction of the − arrow in FIG. 1, FIG. 3 is a side view illustrating the second embodiment, and FIG. arrow view,
FIG. 5 is a diagram showing the swinging state of FIG. 3. 1...Probe holder, 1a...Pinching surface, 1b...
... Hole, 2, 3 ... Probe, 4, 14 ... Guide member, 5, 11 ... Spring, 6, 8 ... Stand, 7 ... Fulcrum pin, 9 ... Eye end, 10 ... Rod Material.

Claims (1)

[Claims] 1 The probe holder installed in the liquid tank, the probe attached to the probe holder, and the beam axis of the ultrasonic wave emitted from the probe are aligned with the flaw detection surface of the object. In an apparatus for positioning a subject in an ultrasonic test, the apparatus includes a carrying means for carrying the subject into a liquid tank so as to face the probe, and a carrying means for placing the subject opposite to the probe. a pair of probe holders; a guide member that is perpendicular to the clamping surface of the probe holder and slidably supports the probe holder in a direction that opens and closes the gap between the opposing clamping surfaces; , when the distance between the opposing clamping surfaces of the probe holder is expanded by a subject carried into the distance while sliding along the guide member, the probe holder resists the expanding force. A spring is provided to generate a force acting on the clamping surface of the holder in the direction of clamping the subject and to expand and contract along the guide member, and a spring is provided to extend and contract along the guide member, and to apply a force to the clamping surface of the holder together with the clamped subject. probe holder,
1. A positioning device for a subject, comprising: a guide member; a base movably supported integrally with a spring;