JPS6243564A - Positioning apparatus for object in ultrasonic inspection - Google Patents

Abstract

PURPOSE:To enable an object to be inspected to be positioned facing a probe precisely vertical thereto, by generating a force on pinching press surfaces of probe holders in the direction of pinching an object to be inspected against a force of expanding the pinching press surfaces when the object being inspected is carried in. CONSTITUTION:In an apparatus so designed to position an object M to be inspected so that the beam axis of an ultrasonic wave emitted from probes 2 and 3 mounted on a pair of probe holders 1 set in a liquid tank may face the flaw detection surface of the object M being inspected, the probe holders 1 having pinching press surfaces 1a for grasping the object M being inspected is held slidably with a guide member 4 in the direction of opening or closing the space between the pinching press surfaces 1a. The space between the pinching press surfaces 1a facing the probe holders 1 is expanded or reduced along the guide member 4 depending on the object M being inspected being carried in, generating a force on the pinching press surfaces 1a of the probe holders 1 in the direction of pinching the object M being inspected with a spring 5 against a force of expanding it when the surfaces are expanded sliding along the guide member 4.

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 the liquid immersion method (the water immersion method is common and will be explained below as the water immersion method). ing.

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 incident angle θi and the refraction angle θr when ultrasonic waves are incident on the steel from water is as follows:
r is about 4 times the incident angle θi, and in oblique angle flaw detection, the angle of incidence is 33° to 27.3' within the range of 14.5' to 27.3'.
It is known that a 90° refracted transverse wave can be obtained, and compared to direct contact angle probes using organic glass etc.
The range of incident angles is small, so delicate 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 move a probe holder installed inside a water tank with a probe attached to a probe holder that is installed inside a water tank, and to place a sample grabbed by a transport means such as a robot installed outside the water 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 on a large number of test objects, but it is difficult to set the center positions of a large number of test objects without error even when using a jig. Even if the settings can be made without errors, there may be errors in the operation of each part of the loading means and the installation position of the probe holder.

Errors in relative positions such as the mounting position of the probe and the position of the water tank itself are accumulated, and it is difficult to correctly orient a large number of subjects perpendicularly to the probe each time, and measurement errors often occur. The reality is that there are. Detecting the occurrence of this measurement error is also increasingly difficult because measurements are normally performed on the premise that the set position of the subject is correct, and measurements may even be performed two or more times to detect this error. Further, there were many problems such as the need for delicate adjustments in adjusting the set position.

[Object of the Invention] The present invention solves the problems of the prior art described above, and eliminates the condition in which the test surface of the test object does not face the probe correctly perpendicularly when the test object is carried into the probe holder. An object of the present invention is to provide a positioning device for a subject in an ultrasonic examination, which can automatically position the subject in a vertically opposed position when loading 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 that supports the opposing clamping surfaces so as to be slidable in the opening/closing direction, and a guide member that supports the opposing clamping surfaces so as to be slidable in the opening/closing direction, and 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 constructing the probe with a tabular spring, even if the test surface of the test object is not correctly perpendicularly opposed to the probe when it is brought in, it is automatically positioned in a position where it is correctly perpendicularly opposed to the probe during measurement. It is a positioning device.

[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 surface of the vibrator. Further, the upper part of the clamping surface la is appropriately rounded or chamfered so that the subject M can be easily inserted. Reference numeral 4 denotes a rod-shaped guide member that is inserted into the hole 1b of the probe holder l 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 40, 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 la. The above configuration is supported on a base 6 via a spring seat 4a.

The subject M is carried into the liquid tank by being grabbed by a carrying means (not shown), and then the subject M is usually held by the probe holder 1 from above on the opposing clamping surface 1a.
inserted in between. 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 object M is inserted with the gap between the clamping surfaces 1a expanded until the desired flaw detection surface is at the position where the probe 2.3 is attached. 5 while sliding, the spring 5 generates a force that opposes the force corresponding to the increased gap between the clamping surfaces 1a, and the compressive force of the spring clamps the subject M between the clamping surfaces 1a. 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. If the waveform or echo pattern is incorrect, that is, if the subject M is inserted between the clamping surfaces 1a in the tilted state shown in FIG. Lift it slightly away from 6. Then, since the pinching surface 1a is pressed against the subject M by the spring 5, it automatically pinches both sides of the tilted subject M, and the two sides of the subject M are brought into close contact and stabilized. 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.
When a deformation of the waveform or echo pattern of an incorrect facing state is determined visually or by a monitor, 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, but 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. For the spring 5, a compression spring was provided between the surface 1c and the spring seat 4a so as to press the surface 1c, but instead of the compression spring, a tension spring was provided between the opposing probe holders 1, and the tension spring and the probe were The probe holder may be locked to clamp the subject M with a force that suppresses the force when the interval between the clamping surfaces 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, regarding the provision of the guide member 4, in this embodiment, the case where the guide member 4 is inserted into the lower part of the probe holder 1 is shown, but the clamping surface 1
Any other position may be used as long as it is within the height range of a. Furthermore, although probes are attached to each probe holder 1, it is also possible to remove one probe and use an I 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 integrated 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 been removed returns to the state of automatically positioning the subject M to be measured next, and repeats the above operation 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. Similar to the first embodiment, this embodiment also shows a case where a flat plate specimen whose flaw detection surface and bottom surface are parallel to each other 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 inserted probe holders l. There is. An elongated eye end 9 is fixed to the outer surface of the spring seat 4a, and its elongated hole loosely fits into a bar 10 fixed upright to the stand 8.

A spring 11 is fitted in the bar 10 between the eye end 9 and the stand 8, so that it can support the unbalanced load that occurs on the left and right sides of the fulcrum pin 7. 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 face the probe in the liquid tank correctly perpendicularly, the first
This is the same as the explanation in the embodiment. However, subject M
When the test object M is inserted between the clamping surfaces 1a in an inclined state as shown in FIG. become.

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. The swinging guide member 14 is guided in the swinging direction by the elongated holes of the eye ends 9 at both ends engaging with the bar 10. When the subject M is inserted to a predetermined position on the clamping surface 1a, the swinging stops.

The unbalanced load caused by the eccentricity 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 extended, and when the rocking is stopped, the spring 11 is adjusted to correspond to the inclination angle of the subject M. The swinging posture shown in FIG. 5 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 subject M is moved by the carrying means to such an extent that the spring seat 4a is slightly separated from the table 6. This is the same as the lifted state, and is nothing but a state in which both surfaces of the subject M and the probe 2.3 are correctly positioned vertically opposing each other. Therefore, in this embodiment, there is no need to visually or monitor to determine whether there is an incorrect waveform or echo pattern deformation in the opposing state.
Just by transporting the parts, the correct opposing state can be automatically obtained. 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.

In this example as well, the subject M explained in the first example
In the case of a flat plate with two parallel surfaces, it is possible to always measure equidistantly automatically, the shape of the clamping surface 1a only needs to be a surface that matches the surface of the subject M to be clamped, and the spring 5 can be changed to a tension spring, the number can be reduced, the position of the guide member 14 (4 in the first embodiment) can be changed, and it can also be applied to the one-probe method. are all the same, and the first . 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 drawings]

The drawings are all detailed explanatory views of the present invention, and FIG. 1 is a side view illustrating the first embodiment, FIG. 2 is a view taken along the nn arrow in FIG. FIG. 4 is a side view illustrating an example, FIG. 4 is a view taken along the line IV-IV in FIG. 3, and FIG. 5 is a diagram showing the swinging state of FIG. 3. 1... Probe holder, 1a... Squeezing surface, 1b...
Hole, 2.3... Probe, 4, 14... Guide member, 5
．． 11... Spring, 6.8... Stand, 7... Fulcrum pin, 9... Eye end, lO... Bar material. Patent Applicant Hitachi Construction Machinery Co., Ltd. Agent Patent Attorney Tadashi Akimoto Minoru No. 1vA Figure 2 Figure 3 Figure 4 M Figure 5

Claims (1)

[Claims] 1. A probe holder installed in a liquid tank, a probe attached to the probe holder, and a beam axis of an ultrasonic wave emitted from the probe. 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 flaw detection surface of the subject and facing the probe. a pair of opposing probe holders having pinching surfaces that sandwich the probe holders; When the distance between the slidably supported guide member and the opposing clamping surface of the probe holder is expanded by a subject carried into the distance while sliding along the guide member, the expansion a spring that generates a force that acts on the clamping surface of the probe holder in the direction of clamping the subject in opposition to the force applied to the probe holder, and is provided to expand and contract along the guide member. A positioning device for a subject, characterized in that: 2. The probe holder installed in the liquid tank, the probe attached to the probe holder, and the beam axis of the ultrasonic waves emitted from the probe In an apparatus for positioning a subject in an ultrasonic test, the device includes a carrying means for carrying the subject into a liquid tank so as to face the probe, and a clamping surface that clamps the subject. a pair of probe holders facing each other; the probe holder is perpendicular to the clamping surface of the probe holder and is slidably supported in a direction in which the gap between the opposing clamping surfaces opens and closes; When the distance between the guide member and the opposing clamping surfaces of the probe holder is expanded by the subject being carried into the distance while sliding along the guide member, the force of the object being expanded is resisted. A spring is provided in the center of the guide member to generate a force acting in the direction of pinching the subject on the clamping surface of the probe holder, and is provided to expand and contract along the guide member. When a specimen is carried in in an inclined state, a fulcrum pin that supports the pair of probe holders so as to be able to swing to either the left or right corresponding to the inclination, and a fulcrum pin that engages with both ends of the guide member to engage with both ends of the guide member. A rod that guides the swinging direction of the probe, and a bar that maintains a swinging posture corresponding to the inclination angle of the subject against the force in the swinging direction during swinging, and that the subject is carried out from the probe holder. 2. A positioning device for a subject, comprising: a spring that is provided to expand and contract along the bar and generate a force to release the swinging posture when the subject is moved.