JP3688265B2 - Ultrasonic flaw detector - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an ultrasonic flaw detector that non-destructively inspects internal defects in flaw detection parts such as welded joints.
[0002]
[Prior art]
Conventionally, ultrasonic flaw detection (UT) is known as means for nondestructively inspecting internal defects such as welded joints. This ultrasonic flaw detection inspection is a nondestructive inspection in which a probe is brought into close contact with the surface of an object to be inspected, and defects are detected by reflection of ultrasonic waves incident on the object to be inspected from the probe. The position of the defect can be known from the time until the reflection of the ultrasonic wave is detected.
[0003]
As this type of prior art, the carriage is intermittently moved from the beginning to the end of the joint welding line, and the ultrasonic probe is moved in the carriage traveling direction and this by a scanning mechanism provided in the carriage every time the carriage is stopped. There is an automatic ultrasonic flaw detector that performs a flaw detection on all the joint weld lines by performing a rectangular scan in a perpendicular direction. According to this ultrasonic flaw detector, full line flaw detection is performed by inspecting the reflection of incident ultrasonic waves while scanning the ultrasonic probe in the front-rear direction with respect to the joint weld line (for example, patent document). 1).
[0004]
On the other hand, since the range in the thickness direction of the object to be inspected by the ultrasonic probe is limited, in order to perform a stable inspection in the entire thickness direction, the ultrasonic probe is placed close to or away from the welded joint. In some cases, the range in which the ultrasonic probe can be inspected is expanded in the thickness direction by performing scanning.
[0005]
[Patent Document 1]
JP-A-5-333010 (first page, FIG. 1)
[0006]
[Problems to be solved by the invention]
However, in the case of the ultrasonic flaw detector described in Document 1, a scanning mechanism is attached to a carriage that runs in the direction of the weld line, and when inspected while running, vibrations and undulations from the carriage are transmitted to the probe and stabilized. Since the flaw detection cannot be performed, the carriage is intermittently driven at a running pitch corresponding to the scanning range, and the square scanning by the running mechanism is performed while the carriage is stopped. Therefore, continuous ultrasonic flaw detection cannot be performed, and a lot of time is required. In addition, there is a possibility that stable ultrasonic flaw detection cannot be performed due to vibrations from a driving device such as a motor even when the motor is stopped.
[0007]
Further, as described above, when the thickness of the object to be inspected is increased, the range of the longitudinal scanning of the ultrasonic probe is increased accordingly, so that the configuration dimension for scanning the probe becomes longer, The whole device becomes large to support.
[0008]
Further, in this ultrasonic flaw detector, it is difficult to inspect the welded joint portion where the flat plates are abutted, and a sufficient effect can be obtained only by ultrasonic flaw detection of a limited welded joint portion.
[0009]
[Means for Solving the Problems]
Therefore, in order to solve the above problems, the present invention provides a guide member on the surface of the object to be inspected at a predetermined distance from the flaw detection part along the flaw detection part of the object to be inspected , and along the guide member, A self-propelled drive carriage and a probe carriage provided with a pair of ultrasonic probes that emit ultrasonic waves from the side of the flaw detection part toward the flaw detection part are separately provided. The probe carriage is connected to the probe carriage by a joint, and the probe carriage is provided with a scanning mechanism that scans the ultrasonic probe in a symmetrical manner to move the ultrasonic probe close to or away from the flaw detection unit. A regulating member for maintaining a distance from the surface of the object to be inspected is provided on the anti-flaw detection side of the probe driver, and the ultrasonic probe is provided on the ultrasonic probe side of the probe driver. A limiting member for limiting the pressing force on the surface of the object to be inspected is provided . In this way, the driving carriage for moving the ultrasonic probe for ultrasonic flaw detection along the flaw detection part and the probe carriage provided with the ultrasonic probe are separated as separate bodies. By connecting the joints with the joint, vibrations and undulations generated in the drive carriage are not transmitted to the ultrasonic probe side, and stable ultrasonic flaw detection can be performed with the ultrasonic probe.
[0010]
Moreover, the thickness direction of the object to be inspected can be widely inspected by scanning the ultrasonic probe symmetrically so as to approach or separate toward the flaw detection portion. In addition, the probe driver that is pressed toward the object to be inspected can stably press the ultrasonic probe side toward the object to be inspected by the regulating member on the anti-flaw detection side. If the pressing force of the probe exceeds the specified value, the pressing force of the ultrasonic probe can be limited by the limiting member, and the ultrasonic probe can be inspected stably even if the inspection conditions change. It can be tested by pressing against the body.
[0011]
Further, if a guide member guided by the guide member is provided in the drive carriage and the probe carriage, and a pressing member that presses the probe driver toward the object to be inspected is provided in the probe carriage, The driving carriage and the probe carriage are stably moved along the guide member, and the probe driving device of the stably moving probe carriage is pressed against the inspected object side with a predetermined pressure to Stable ultrasonic flaw detection with an acoustic probe is possible.
[0012]
Furthermore, if the joint is formed by a universal joint that is arranged substantially coaxially with the guide member, the probe carriage moved by the drive carriage can be moved around the guide member, so that the probe carriage is rotated. It can be moved stably without generating a moment or the like.
[0014]
Further, if the pressing member is constituted by a spring provided between the probe carriage and the probe driving device, and the spring is disposed before and after the traveling direction of the probe driving device, the simple operation can be achieved. The front and rear of the probe driving machine can be stably pressed toward the object to be inspected by the spring force of the spring, which is a configuration, and the pressing force can be easily changed by replacing the spring.
[0016]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a perspective view of an ultrasonic flaw detector showing an embodiment of the present invention, FIG. 2 is a view taken in the direction of arrows II-II shown in FIG. 1, FIG. 3 is a view taken in the direction of arrows III-III shown in FIG. 4 is an enlarged view of the IV part shown in FIG. 2, and FIG. For the sake of explanation, part of the drawing is shown in cross section. In this embodiment, a plate material butt-welded as an object to be inspected will be described as an example, and an ultrasonic flaw detection apparatus that performs ultrasonic flaw detection in the weld line direction of the weld joint portion will be described as an example.
[0017]
As shown in FIG. 1, a welded joint portion of a test object 1 welded by abutting plate materials is a flaw detection portion 2, which is a weld line continuous in the vertical direction shown in the figure. A guide member 3 is provided in parallel to the flaw detection part 2 at a position away from the flaw detection part 2 by a predetermined distance. In this embodiment, a pipe rail having a cylindrical cross section is used as the guide member 3. The guide member 3 may have a square cross section or another cross section.
[0018]
The guide member 3 is provided with a drive carriage 4 that travels along the guide member 3 and a probe carriage 5 that is connected to the drive carriage 4 and moves along the guide member 3. The drive carriage 4 and the probe carriage 5 constitute an ultrasonic flaw detector 6. The control device for controlling these may be provided in the drive carriage 4 or in a remote control room or the like.
[0019]
The drive carriage 4 is supported by its own weight by wheels 11 (four places) in contact with the surface of the object 1 to be inspected, and by guide rollers 12 (guide members: four places) rotating in contact with both sides of the guide member 3. It is comprised so that it may move along. The probe carriage 5 is configured such that its own weight is supported by guide rollers 13 (guide members: four places) rotating in contact with both side portions of the guide member 3, and moved along the guide member 3 by the guide rollers 13. Has been.
[0020]
The probe carriage 5 is provided with a probe driver 15 that extends in a direction crossing the flaw detection unit 2. An ultrasonic probe 17 is provided on the scanning unit 16 of the probe driver 15 so as to be positioned on both sides of the flaw detection unit 2.
[0021]
The drive carriage 4 and the probe carriage 5 are connected by a joint 14 so that the probe carriage 5 moves following the movement of the drive carriage 4. The drive carriage 4 and the control unit 18 of the probe carriage 5 are connected by a wire 19, and the drive carriage 4 is connected by a control device (not shown) by a wire 20.
[0022]
As shown in FIG. 2, the guide roller 13 provided in the probe carriage 5 has an outer surface with substantially the same curvature as the outer surface of the guide member 3 having a circular cross section. The guide member 3 is fixed to the surface of the inspection object 1 with a support material 21 having a predetermined height, and the probe carriage 5 guides the guide member 3 by sandwiching the guide member 3 from both sides with the guide roller 13. It is attached to the member 3. The left guide roller 13 </ b> A shown in the figure is rotatably supported by a shaft 22 and rotates following the movement of the probe carriage 5. The right guide roller 13B is rotatably supported by the slide member 24 by the shaft 23, and rotates following the movement of the probe carriage 5. The slide member 24 is provided so as to be slidable along a slide portion 25 provided at a lower portion of the carriage base plate 27 of the probe carriage 5. A spring 26 is provided inside the slide portion 25, and the guide roller 13 </ b> B is always pressed toward the guide member 3 by the spring 26. With such a configuration, the guide member 3 is held between the left and right guide rollers 13A and 13B with a predetermined force (the force of the spring 26). By attaching the probe carriage 5 in this way, the probe carriage 5 is kept floating at a predetermined distance from the surface of the inspection object 1.
[0023]
A pressing shaft 28 is erected on the top of the carriage base plate 27 of the probe carriage 5. In this embodiment, as shown in FIG. 1, pressing shafts 28 are provided at front, rear, left and right positions of the guide member 3. The pressing shaft 28 projects upward through an insertion hole 30 provided in the drive base plate 29 of the probe drive machine 15 and a spring 32 provided in the spring cover 31. The pressing shaft 28 that protrudes upward from the spring cover 31 is connected at its left and right upper ends by a holding member 33.
[0024]
Further, the upper portion of the pressing shaft 28 from a predetermined position is formed in a guide portion 34 having a slightly smaller diameter than the inner diameter of the spring cover 31. The guide portion 34 moves up and down along the inner surface of the spring cover 31 so that the pressing shaft 28 and the spring cover 31 slide substantially on the same axis. The lower surface of the guide portion 34 is an upper end support portion of the spring 32.
[0025]
In this way, the upper end of the spring 32 is supported by the guide portion 34 of the pressing shaft 28, so that the drive machine base plate 29 is pressed toward the surface of the device under test 1 by the force of the spring 32. At this time, the spring cover 31 is guided by the guide portion 34 of the pressing shaft 28, and the entire probe driver 15 is pressed toward the object 1 to be inspected substantially in parallel. The force for pressing the probe driver 15 toward the inspection object 1 can be easily achieved by changing the spring 32. For example, when the lower surface of the inspection object 1 is inspected upward, For example, when inspecting the inspected object 1 on the inclined surface sideways, it is possible to easily change to the spring 32 having a force according to the use conditions.
[0026]
On the other hand, the scanning unit 16 of the probe driver 15 is provided with an ultrasonic probe 17 that emits ultrasonic waves from the side of the flaw detection unit 2 toward the flaw detection unit 2. The ultrasonic probe 17 is provided on a support member 39 that protrudes from a moving member 38 that moves along a guide rail 37 provided in the axial direction of the scanning unit 16 toward the inspection object 1. Yes.
[0027]
As shown in FIG. 3, the guide rail 37 is provided in the central axis direction of the scanning unit 16, and a timing belt 40 is provided around the guide rail 37. The timing belt 40 is hung on sprockets 41 provided at both ends of the scanning unit 16, and the drive sprocket 41 provided on the control unit 17 side (right side in the figure) is configured to be rotatable by a drive motor 35. Yes. The moving members 38 are respectively fixed by fixing members 42 on different linear portions (upper and lower sides in the drawing) of the timing belt 40 thus provided. By fixing in this way, if the timing belt 40 is intermittently moved in the forward direction / reverse direction at a predetermined distance, the ultrasonic probes 17 can be operated so as to approach or separate from each other. In the case of this configuration, the ultrasonic wave emitted from the left or right ultrasonic probe 17 is received by the right or left ultrasonic probe 17.
[0028]
As shown in FIG. 4, the ultrasound probe 17 includes a guide shaft 43 that is guided in a vertical direction by a support member 39 of a moving member 38 that moves along a guide rail 37, and a lower end of the guide shaft 43. And a probe main body 46 supported by a horizontal support shaft 45 provided on the holding portion 44. The probe main body 46 is provided with wheels 36. Further, the holding portion 44 provided with the probe main body 46 is pressed toward the inspection object 1 by a spring 47 provided on the guide shaft 43 and moves in a direction approaching or separating from the surface of the inspection object 1. It is possible. When the holding portion 44 moves up and down, the guide shaft 43 is guided to the support member 39.
[0029]
As described above, the probe body 46 to be pressed is inspected by providing the probe body 46 on the holding portion 44 that moves vertically in the vertical direction so that the support shaft 45 can swing in the horizontal direction. It is in close contact with the surface of the body 1. These are the scanning parts of the scanning mechanism.
[0030]
On the other hand, as shown in FIG. 2, a regulating member 48 that keeps the distance between the scanning unit 16 and the surface of the inspection object 1 is provided on the anti-flaw detection unit 2 side of the scanning unit 16 of the probe driver 15. Yes. The restricting member 48 is a wheel 51 attached by a shaft 50 to a bracket 49 provided from the scanning unit 16 toward the inspection object 1, and is configured to be rotatable while being in contact with the surface of the inspection object 1. Has been. The restricting member 48 is provided on the anti-ultrasonic probe 17 side with the guide member 3 interposed therebetween. By providing the restricting member 48, the restricting member 48 is entirely pressed toward the inspected object 1 by the spring 32. The distance by which the regulating member 48 side of the probe driver 15 moves to the surface side of the inspection object 1 is regulated. By restricting the movement of the probe driver 15, which is entirely pressed by the spring 32 to the object 1 to be inspected, by the restriction member 48, the fixed guide member 3 is centered. Further, the ultrasonic probe side is pressed against the surface side of the inspection object 1.
[0031]
In other words, the probe driver 15 that is constantly pressed toward the object 1 to be inspected by the spring 32 provided on the probe carriage 5 has its anti-ultrasonic probe side determined by the regulating member 48 at a certain distance. The force to the surface side of the inspection object 1 acts on the ultrasonic probe 17 side of the probe driver 15. As a result, the probe body 46 urged from the probe driver 15 to the inspected object 1 side by the spring 47 is always pressed against the surface of the inspected object 1 with a certain pressure and is in close contact. It is possible to perform ultrasonic flaw detection.
[0032]
Further, on the ultrasonic probe 17 side of the scanning unit 16, a limiting member 52 that restricts pressing of the ultrasonic probe 17 against the inspection object 1 is provided. The restricting member 52 is a wheel 55 attached by a shaft 54 to a bracket 53 provided from the scanning unit 16 toward the inspection object 1, and is configured to be rotatable while being in contact with the inspection object 1. Yes. When the ultrasonic probe 17 is pressed against the surface of the inspection object 1 with a predetermined pressing force, the limiting member 52 is in a state of being floated with a slight clearance from the surface of the inspection object 1. In addition, when the ultrasonic probe 17 is pressed beyond a predetermined pressing force, the ultrasonic probe 17 is brought into contact with the surface of the inspection object 1 to prevent a large force from acting on the ultrasonic probe 17.
[0033]
As shown in FIG. 5, the drive carriage 4 and the probe carriage 5 are connected by a universal joint 14 having a ball joint structure. This universal joint 14 is provided between the mounting bracket 56 provided on the probe carriage 5 and the drive carriage 4, and each of them is provided with a ball portion 57 serving as a spherical sliding surface, and can be angularly displaced. So that they are connected. By connecting the drive carriage 4 and the probe carriage 5 with such a universal joint 14, vibrations generated by the drive motor 58 on the drive carriage 4 side, etc., and traveling on the surface of the object 1 to be inspected by the wheels 11. Even if a swell motion or the like occurs in the driving carriage 4, the vibration or swell is not directly transmitted to the probe carriage 5 side by being absorbed by the displacement of the universal joint 14. The universal joint 14 may have another configuration such as a universal joint.
[0034]
Further, as shown in FIG. 1, the universal joint 14 is disposed substantially coaxially with the guide member 3, and the traction force of the drive carriage 4 is substantially traveled between the guide rollers 13 </ b> A and 13 </ b> B of the probe carriage 5. I try to work at the center. This prevents a rotational moment from acting on the probe carriage 5.
[0035]
According to the ultrasonic flaw detection apparatus 6 configured as described above, this driving is performed by guiding the guide member 3 of the pipe rail provided along the flaw detection portion 2 to cause the drive carriage 4 to self-run at a predetermined speed. Following the carriage 4, the probe carriage 5 moves along the guide member 3 at the same speed. The probe carriage 5 is provided with an ultrasonic probe 17 for ultrasonic flaw detection of the flaw detection unit 2 from the side of the flaw detection unit 2, and a drive motor 35 provided in the probe drive unit 15. By intermittently performing forward / reverse rotation in the scanning range, the drive carriage 4 can be run while scanning the ultrasonic probe 17 to be close to or separated from the flaw detection unit 2 by the timing belt 40. As a result, an ultrasonic flaw detector 6 capable of performing ultrasonic flaw detection while moving along the flaw detector 2 is obtained. At this time, a liquid such as water is supplied between the ultrasonic probe 17 and the surface of the object 1 to be inspected, and a layer of this liquid between the ultrasonic probe 17 and the surface of the object 1 to be inspected. An air layer is prevented from being formed.
[0036]
Moreover, since the probe carriage 5 for ultrasonic flaw detection is separated from the drive carriage 4 for moving the ultrasonic flaw detector 6 and connected by the universal joint 14, the vibration of the drive motor 58 of the drive carriage 4 is detected by the ultrasonic probe. Stable ultrasonic flaw detection can be performed without being transmitted to the transducer 17 or vibrations or undulations of the drive carriage 4 itself being transmitted to the ultrasonic probe 17.
[0037]
In addition, the operation for ultrasonic flaw detection while moving in this manner can be automated by setting the control device or the like, and can be configured as the automatic ultrasonic flaw detection device 6.
[0038]
In addition, the drive carriage 4 and the probe carriage 5 move along the guide member 3, and the ultrasonic probe 17 is pressed from the probe carriage 5 toward the surface of the inspection object 1. Therefore, the ultrasonic probe 17 can be stably in contact with the surface (flaw detection surface) of the inspection object 1, and the inspection object 1 having the surface formed with a predetermined curvature is inspected from the outside or inspected from the inside. In such a case, it is possible to perform stable ultrasonic flaw detection regardless of whether the flaw detection posture is downward or sideways.
[0039]
Therefore, for example, it is possible to realize an ultrasonic flaw detection apparatus 1 that can stably perform flaw detection on a wire welded joint having a curvature radius of several tens of meters, such as a shipping LPG or LNG tank, and can also realize automation thereof. The ultrasonic flaw detector 1 is obtained.
[0040]
In the above embodiment, the configuration in which the probe carriage 5 is pulled by the drive carriage 4 has been described. However, the probe carriage 5 may be pushed by the drive carriage 4, and the ultrasonic probe 17 may be used. Other configurations may be used as long as the configuration for ultrasonic flaw detection and the configuration for movement along the flaw detection unit 2 are separate.
[0041]
Further, the above-described embodiment is an embodiment, and various modifications can be made without departing from the gist of the present invention, and the present invention is not limited to the above-described embodiment.
[0042]
【The invention's effect】
The present invention is implemented in the form as described above, and vibrations and undulations, etc. generated in a carriage that moves the ultrasonic probe along the flaw detection part are not transmitted to the ultrasonic probe side, and the ultrasonic probe It becomes possible to carry out ultrasonic flaw detection with the stability.
[Brief description of the drawings]
FIG. 1 is a perspective view of an ultrasonic flaw detector showing an embodiment of the present invention.
FIG. 2 is a view taken in the direction of arrows II-II shown in FIG.
3 is a view taken in the direction of arrows III-III shown in FIG.
FIG. 4 is an enlarged view of a portion IV shown in FIG.
FIG. 5 is a VV arrow view shown in FIG. 1;
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Test object 2 ... Flaw detection part 3 ... Guide member 4 ... Drive carriage 5 ... Probe carriage 6 ... Ultrasonic flaw detector 11 ... Wheel 12 ... Guide roller 13 ... Guide roller 14 ... Universal joint 15 ... Probe drive Machine 16 ... Scanning part 17 ... Ultrasonic probe 18 ... Control part 21 ... Supporting material 24 ... Sliding member 25 ... Sliding member 26 ... Spring 27 ... Dolly base plate 28 ... Pressing shaft 29 ... Driver base plate 30 ... insertion hole 31 ... Spring cover 32 ... Spring 33 ... Holding member 34 ... Guide section 35 ... Drive motor 36 ... Wheel 37 ... Guide rail 38 ... Moving member 39 ... Support member 40 ... Timing belt 41 ... Sprocket 42 ... Fixed member 43 ... Guide shaft 44 ... Holding part 45 ... Support shaft 46 ... Probe body 47 ... Spring 48 ... Restricting member 49 ... Bracket 51 ... Wheel 52 ... Restricting member 53 ... Bracket 55 ... Wheel 56 Mounting bracket 57 ... ball portion 58 ... drive motor

Claims (4)

A guide member is provided on the surface of the object to be inspected at a predetermined distance from the flaw detection part along the flaw detection part of the object to be inspected , and along the guide member, a self-propelled drive carriage and a side part of the flaw detection part A probe carriage provided with a pair of ultrasonic probes that emit ultrasonic waves toward the flaw detection portion is provided separately, and the drive carriage and the probe carriage are connected by a joint, and the probe A probe driving machine provided with a scanning mechanism that scans the ultrasonic probe in a symmetrical manner that moves close to or away from the flaw detection part is provided on the child carriage, and the probe driving machine is provided on the side opposite to the flaw detection part. A restricting member that maintains a distance from the surface of the inspection object is provided, and a limiting member that restricts the pressing force of the ultrasonic probe to the surface of the inspection object is provided on the ultrasonic probe side of the probe driver. An ultrasonic flaw detector provided . Rutotomoni provided a guide member which is guided by the guide member in the probe carriage and the drive carriage, claims the probe drive machine該探probe carriage provided with a pressing member for pressing the object to be inspected side The ultrasonic flaw detector according to 1 . The pressing member, constituted by a spring which is provided between the probe carriage and probe drive motor, the spring, No mounting Claim 2 Symbol is disposed in the longitudinal direction of travel of the probe drive motor Ultrasonic flaw detector.   The ultrasonic flaw detector according to any one of claims 1 to 3, wherein the joint is configured by a universal joint that is disposed substantially coaxially with the guide member.

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