JP2012225746A - Ultrasonic flaw detection method and ultrasonic flaw detection apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ultrasonic flaw detection method and ultrasonic flaw detection apparatus capable of simply improving inspection accuracy with a simple apparatus.SOLUTION: An ultrasonic flaw detection method is the method using an ultrasonic flaw detection apparatus which includes: a sensor unit 2 that holds ultrasonic probes 7, 8; and a unit support 3 that holds the sensor unit and is fixed to an inspection surface, in which the sensor unit is detachable from the unit support. The unit support from which the sensor unit is detached is positioned at an inspection position, and the sensor unit is then mounted on the unit support, so that ultrasonic flaw detection is performed.

Description

  The present invention relates to an ultrasonic flaw detection method and an ultrasonic flaw detection apparatus for inspecting the presence or absence of a defect in a boundary layer of a structure or a material having different material layers such as steel plate and concrete.

  For bridges or elevated floors of expressways, composite floor slabs in which concrete is cast on the installed steel plates are used. In the composite floor slab, concrete bears the compressive strength and the steel plate bears the tensile strength, and the concrete and the steel plate share the strength, so that sufficient strength is exhibited as a composite floor slab.

  In addition, in order for the composite floor slab to exhibit sufficient strength, it is required that the boundary layer between the steel plate and the concrete is in close contact, but an unfilled portion is generated when the concrete is placed or is long. A steel plate may corrode in a boundary layer with use of a period, and a crevice may be formed in a boundary layer. If a gap is generated in the boundary layer, the strength of the composite slab is reduced. For this reason, it is necessary to inspect the integrity of the boundary layer, such as the presence or absence of unfilled portions of the boundary layer, the occurrence of corrosion, and the progress of corrosion.

  As a method for inspecting the soundness of the boundary layer, there is an ultrasonic flaw detection method, and as disclosed in Patent Document 1, in particular, ultrasonic flaw detection using low-frequency ultrasonic waves (25 [kHz] to 250 [kHz]). When the above is performed, reflection at the unfilled portion and gap in the boundary layer is obtained, and the soundness of the boundary layer can be inspected.

  The metal corrosion inspection apparatus disclosed in Patent Document 1 has a large structure in which a girder is passed between steel girders, a guide rail is set on the girder, and the girder runs on the guard rail.

  However, in actual ultrasonic flaw detection inspections, there are many cases where an operator simply performs a simple operation such as directly inspecting the soundness of the boundary layer by pressing the ultrasonic sensor against the inspection location.

  In this case, it is a work at a high place, and it is a flaw detection inspection in an upward posture in which the ultrasonic sensor is pressed from the lower side to the lower surface of the composite floor slab. In particular, when there are a large number of inspection points, the burden on the operator is large. Furthermore, since the flaw detection inspection is in an upward posture, the pressing state of the ultrasonic sensor is not stable, and the inspection result may vary.

JP 2004-163263 A

  In view of such circumstances, the present invention provides an ultrasonic flaw detection method and an ultrasonic flaw detection apparatus that can improve the inspection accuracy with a simple apparatus in a simple manner.

  The present invention includes a sensor unit that holds an ultrasonic probe, and a unit support that holds the sensor unit and can be fixed to an inspection surface. The ultrasonic wave unit is detachable from the unit support. An ultrasonic flaw detection method using a flaw detection apparatus, wherein a unit support with the sensor unit removed is positioned at an inspection position, and then the sensor unit is mounted on the unit support and ultrasonic flaw detection is performed. It concerns the method.

  Further, the present invention provides an ultrasonic flaw detection method in which a plurality of the unit supports are provided, each of the plurality of unit supports is installed at an inspection position, and the sensor units are sequentially mounted on the unit support to perform ultrasonic flaw detection. It is concerned.

  The present invention also relates to an ultrasonic flaw detection method in which the unit support includes moving means, and the unit support is moved in order to change the inspection location to perform ultrasonic flaw detection.

  The present invention also includes a sensor unit that holds an ultrasonic probe, a unit support that holds the sensor unit and can be fixed to an inspection surface, and the sensor unit can be attached to and detached from the unit support. The present invention relates to an acoustic flaw detector.

  According to the present invention, the unit support includes a main frame body having a space for housing the sensor unit, and a rotation frame body that is rotatably provided on the main frame body and opens and closes the main frame body. The sensor unit has a unit pressing spring that is held by the unit support so as to be displaceable in a direction perpendicular to the inspection surface and extends upward, and compresses the unit pressing spring when the rotating frame is closed. And an ultrasonic flaw detector in which the ultrasonic probe is pressed against the inspection surface via the unit pressing spring.

  According to the present invention, the sensor unit includes a first probe holder that holds a first probe that oscillates ultrasonic waves, and a second probe that holds a second probe that receives reflected ultrasonic waves. A first probe holder and the second probe holder according to an ultrasonic flaw detector connected by a free coupling.

  The present invention also relates to an ultrasonic flaw detector in which the main frame body further includes a positioning guide plate, and a marking line indicating an inspection position is provided on the positioning guide plate.

  The present invention also relates to an ultrasonic flaw detection apparatus in which the main frame body includes a moving means and is movable along a rail attached to the inspection surface.

  Further, in the present invention, the rail is two rails, and at least two places of the rails are connected by a connecting rod, the parallelism of the two rails is determined, and a universal joint is provided in the middle of the connecting rod. The present invention relates to an ultrasonic flaw detector in which the connecting rod can be bent.

  According to the present invention, the sensor unit that holds the ultrasonic probe, and the unit support that holds the sensor unit and can be fixed to the inspection surface, the sensor unit can be attached to and detached from the unit support. An ultrasonic flaw detection method using an ultrasonic flaw detection apparatus, wherein a unit support with the sensor unit removed is positioned at an inspection position, and then the sensor unit is mounted on the unit support to perform ultrasonic flaw detection. This eliminates the need to hold the sensor unit by hand, reduces the burden on the operator, stabilizes the pressed state of the ultrasonic sensor, and improves inspection accuracy.

  According to the present invention, there is provided a sensor unit that holds an ultrasonic probe, a unit support that holds the sensor unit and can be fixed to an inspection surface, and the sensor unit can be attached to and detached from the unit support. Therefore, the sensor unit can be held at the inspection location by the unit support, the operator's holding action can be omitted, the burden on the operator is reduced, the pressing state of the ultrasonic sensor is stabilized, and the inspection accuracy is improved. Excellent effect of improving.

1 is a perspective view from above of an ultrasonic flaw detector according to an embodiment of the present invention. It is a perspective view from the lower part of this ultrasonic flaw detector. It is a perspective view from the top which shows the state which opened the rotation frame with this ultrasonic flaw detector. It is a perspective view from the top which shows the state which removed the sensor unit from the main frame of the ultrasonic flaw detector. It is a perspective view from the upper side of the state which removed the 1st probe and the 2nd probe from the 1st probe holder of the sensor unit, and the 2nd probe holder. It is a perspective view from the top of the state which removed the sensor unit from the unit support and closed the rotation frame. The jig | tool for attaching the said 1st probe and a 2nd probe to a 1st probe holder and a 2nd probe holder is shown, (A) is a top view, (B) is a side view. . It is a perspective view from the lower part of the state which installed the said unit support in the lower surface of the synthetic floor slab. (A) is a graph which shows the result of the ultrasonic flaw inspection by the conventional method, (B) is a graph which shows the result of the ultrasonic flaw inspection at the time of implementing this invention.

  Embodiments of the present invention will be described below with reference to the drawings.

  FIG. 1 is a perspective view of an ultrasonic flaw detector 1 according to an embodiment of the present invention as viewed from above, and FIG. 2 is a perspective view as viewed from below.

  The ultrasonic flaw detector 1 mainly includes a sensor unit 2, a unit support 3, and a measuring device 4.

  First, the sensor unit 2 will be described with reference to FIGS. 4 and 5.

  The sensor unit 2 has a first probe holder 5 and a second probe holder 6. The first probe holder 5 holds a first probe 7 that is an ultrasonic probe that oscillates ultrasonic waves, and the second probe holder 6 receives an ultrasonic probe that receives reflected waves. A second probe 8 which is a touch is held. The first probe 7 and the second probe 8 are arranged symmetrically with respect to the vertical center 9 of the sensor unit 2. Since the first probe holder 5 and the second probe holder 6 have a symmetrical shape, the first probe holder 5 will be described below.

  A probe holding hole 11 having a diameter slightly larger than the outer diameter of the first probe 7 is formed through the first probe holder 5 in the vertical direction. The probe holding hole 11 is a circle in which the vertical center 9 side is partially cut off, and a slit 12 is formed on the opposite center side, and the probe gripping pieces 13 and 13 divided by the slit 12 are formed. Is capable of approaching and separating by elastic deformation around the hinge portion 14.

  A probe fixing bolt 15 penetrating the probe holding pieces 13 and 13 is provided so as to cross the slit 12, and a hole through which the probe fixing bolt 15 passes is formed in the probe holding pieces 13 and 13. One of the two is a screw hole and the other is a play hole. When the probe fixing bolt 15 is tightened, the probe gripping pieces 13 and 13 approach each other, and loosen and separate from each other. The probe holding hole 11 expands and contracts.

  Blocks 16 are fixed to the side surfaces of the probe gripping pieces 13, 13. A vertical spring holding shaft 17 is erected on the block 16, and a synthetic resin slide washer 18 is attached to the spring holding shaft 17. 18 is slidably fitted in the upper and lower two pieces, and a unit pressing spring 19 is provided between the slide washers 18, 18, and the unit pressing spring 19 can be expanded and contracted with the spring holding shaft 17 as a guide. . Further, the diameter of the slide washer 18 is larger than the diameter of the unit pressing spring 19, and a flange for preventing the slide is formed at the upper end of the spring holding shaft 17, and the upper slide washer 18 holds the spring. The shaft 17 is not pulled out.

  Two unit support pins 21 protrude in parallel with the slit 12 on the surface opposite to the center of the first probe holder 5, and a flange 21 a is formed at the tip of the unit support pin 21. Yes.

  The second probe holder 6 has the same structure as the first probe holder 5, but the unit support pin 22 projecting from the second probe holder 6 is not formed with a flange. .

  The blocks 16, 16 of the first probe holder 5 and the second probe holder 6 are positioned opposite to each other due to the symmetry of the first probe holder 5 and the second probe holder 6. However, the blocks 16 and 16 are connected by a universal coupling 23.

  The universal coupling 23 has at least an elastic body that can be deformed in two axial directions, and the first probe holder 5 and the second probe holder 6 are centered on the universal coupling 23. It is possible to perform relative bending deformation and relative torsional deformation.

  The first probe 7 and the second probe 8 can be fitted into and removed from the probe holding holes 11 and 11 of the first probe holder 5 and the second probe holder 6, respectively. The first probe 7 and the second probe 8 are provided with C-shaped stoppers 24 and 24, respectively.

  The stopper 24 has a two-part structure and is integrated with a bolt 25, and is fastened to the first probe 7 or the second probe 8 by tightening the bolt 25. The stoppers 24 and 24 also enable contact adjustment for freely rotating the first probe 7 and the second probe 8. The stoppers 24 and 24 may not be provided when sufficient contact adjustment is difficult or not particularly necessary, for example, when the stoppers 24 and 24 are installed in a place where they are difficult to reach. When the inspection is performed with the ultrasonic flaw detector 1 facing upward, for example, as shown in FIG. 2, the probe fixing bolt 15 is loosened for contact adjustment, and the first probe 7 and the When the second probe 8 is rotated, the stopper 24 regulates the downward displacement of the first probe 7 and the second probe 8, maintains the set protrusion amount, and The first probe 7 and the second probe 8 are prevented from falling.

  Thus, the first probe 7 and the second probe 8 are respectively inserted into the probe holding holes 11, and the probe fixing bolts 15 are tightened. The probe 7 and the second probe 8 can be fixed to the first probe holder 5 and the second probe holder 6.

  FIG. 4 shows a state where the first probe 7 and the second probe 8 are fixed to the first probe holder 5 and the second probe holder 6 and integrated. . The cables 26 and 27 connected to the first probe 7 and the second probe 8 are connected to the measuring device 4.

  The measuring device 4 detects the position and size of the boundary layer abnormality such as a gap existing in the boundary layer based on signals from the first probe holder 5 and the second probe holder 6.

  Next, the unit support 3 will be described with reference to FIGS. 3, 4, and 6.

  The unit support 3 has a rectangular planar shape, and a magnet block 31 is disposed at each vertex of the rectangle. The magnet block 31 incorporates a rotatable magnet, and the magnet block 31 can be attracted to and detached from the magnetic body by rotating the magnet through a knob 32.

  A pair of the magnet blocks 31 are connected to each other by the vertical beams 33 and 33 arranged on two parallel sides of the rectangle, and are orthogonal to the other two parallel sides of the rectangle, that is, the vertical beam 33. A first horizontal beam 34 is disposed on one of the sides, and a second lateral beam 35 is disposed on the other of the sides, and ends of the first lateral beam 34 and the second lateral beam 35 correspond to the corresponding magnet blocks. A rectangular main frame 36 is constituted by the vertical beams 33, 33, the first horizontal beam 34, the second horizontal beam 35, and the four magnet blocks 31.

  Bearing portions 37 projecting upward are provided on the upper surface of the first transverse beam 34 at a predetermined interval. Each bearing portion 37 is provided with a shaft 38 parallel to the first transverse beam 34, and a lever. 39 is rotatably provided on the first transverse beam 34 via the shaft 38.

  The lever 39 is provided with a slit hole 41 extending in parallel with the longitudinal beam 33, and the width of the slit hole 41 is larger than the diameter of the spring holding shaft 17 and further than the diameter of the slide washer 18. It is getting smaller. A handle 42 is attached to the upper surface of the lever 39. The handle 42 is preferably provided with a rubber grip 43 for preventing slipping.

  A lock shaft 44 parallel to the first transverse beam 34 passes through the front ends of the two levers 39, 39, and the front ends of the lever 39 are connected by the lock shaft 44. The levers 39, 39 and the lock A rotating frame 45 is constituted by the shaft 44. The rotating frame 45 rotates about the shaft 38 and opens and closes above the main frame 36.

  Both end portions of the lock shaft 44 protrude from the levers 39 and 39, respectively, and the protruding both end portions form engaging portions 44a and 44a, respectively.

  A clamp tool 46 is provided on the top end of the vertical beam 33, that is, the upper surface of the end of the second horizontal beam 35. The clamp tool 46 includes a concave groove 47, a clamp piece 48, and a release lever 49. The engaging portion 44a can be fitted in and removed from the concave groove 47, the clamp piece 48 can be advanced and retracted into the concave groove 47, and when the engaging portion 44a is press-fitted into the concave groove 47, the The clamp piece 48 engages with the engaging portion 44a, the engaging portion 44a is fixed to the clamp tool 46, and when the release lever 49 is pulled up, the engagement of the clamp piece 48 is released, and the engagement The portion 44 a can be detached from the concave groove 47.

  The first transverse beam 34 is provided with two long holes 51 at predetermined intervals, and the long axis of the long hole 51 is vertical, that is, perpendicular to the longitudinal direction of the first transverse beam 34. It has become. The second transverse beam 35 is provided with a notch hole 52 at a position facing the elongated hole 51, and the upper end of the notch hole 52 is cut off and opened upward. Both ends of the part are chamfered.

  A lock plate 53 is slidably provided in the longitudinal direction of the second transverse beam 35 on the outer surface of the second transverse beam 35, that is, on the opposite side of the side surface facing the first transverse beam 34. The second transverse beam 35 is formed with a flange piece 54 extending in the sliding direction of the lock plate 53 (upper left direction in FIG. 6). The flange piece 54 corresponds to the two cutout holes 52. .

  The lock plate 53 is completely retracted from the notch hole 52 at one stroke end, completely opens the upper end of the notch hole 52 (unlocked state), and the notch hole 52 at the other stroke end. The upper end of the notch hole 52 is closed (locked state). Further, the lock plate 53 has a lock bolt 55, and the lock bolt 55 is tightened at both stroke ends of the lock plate 53 so that the unlocked state or the locked state of the lock plate 53 is maintained. It has become. Even when the lock bolt 55 is loosened, the flange 21a formed at the tip of the unit support pin 21 is hooked on the flange 54, so that the sensor unit 2 and the unit support 3 are prevented from falling, and safety is improved. high.

  Positioning guide plates 56 are attached to the four magnet blocks 31. The outer shape of the positioning guide plate 56 is substantially rectangular, and the center portion is punched into a substantially rectangular shape. The lower surface of the positioning guide plate 56 is slightly retracted from the lower surface of the magnet block 31, that is, the attracting surface (in FIG. 2). , Indicated by g). The positioning guide plate 56 is preferably a transparent material, for example, a transparent synthetic resin plate.

  A horizontal ruled line 57 perpendicular to the longitudinal direction is engraved on the center surface of the long side portion of the positioning guide plate 56, and the longitudinal direction is formed on the center surface of the short side portion of the positioning guide plate 56. An orthogonal vertical ruled line 58 is engraved.

  An extension line of the horizontal ruled line 57 and an extension line of the vertical ruled line 58 intersect at the center of the positioning guide plate 56. The center of the positioning guide plate 56 is set to coincide with the vertical center 9. Therefore, the horizontal ruled lines 57 and the vertical ruled lines 58 function as inspection position display means for indicating the inspection position. Further, instead of the horizontal ruled lines 57 and the vertical ruled lines 58, an arrow-shaped protrusion or the like may be formed.

  In order to reduce the weight of the unit support 3, the structural materials such as the vertical beam 33, the first horizontal beam 34, the second horizontal beam 35, and the lever 39 are made of aluminum or an aluminum alloy, and the weight is appropriately removed. A hole may be drilled.

  As shown in FIGS. 1 to 3, the sensor unit 2 is loaded in a space surrounded by the main frame 36.

  Hereinafter, loading of the sensor unit 2 into the unit support 3 will be described.

  The rotating frame body 45 is pulled upward to open the space surrounded by the main frame body 36. Further, the lock plate 53 is slid to open the upper end of the notch hole 52.

  The unit support pin 22 is inserted into the elongated hole 51 obliquely from above, rotated around the unit support pin 22, and the unit support pin 21 is fitted into the cutout hole 52 from above. Next, the lock plate 53 is slid, and the upper end of the notch hole 52 is closed by the flange piece 54 to lock the unit support pin 21 in the notch hole 52.

  The state in which the unit support pin 21 is locked and the unit support pin 22 is inserted into the elongated hole 51 is a state in which the sensor unit 2 is held by the main frame 36, and as described above, the sensor The vertical center 9 of the unit 2 is in a state where it coincides with the intersection of the horizontal ruled lines 57 and the vertical ruled lines 58.

  The sensor unit 2 is constrained in the longitudinal direction of the longitudinal beam 33 and the longitudinal direction of the first transverse beam 34, that is, in the plane 2 direction. The long hole formed by the notch hole 52 and the flange piece 54 can be displaced.

  When the attachment of the second probe holder 6 to the main frame 36 is completed, the rotary frame 45 is rotated in the closing direction. In the process of closing the rotating frame body 45, the lever 39 pushes down the slide washer 18 by inserting the spring holding shaft 17 into the slit hole 41 and further rotating the rotating frame body 45. The unit pressing spring 19 is bent.

  When the rotating frame 45 is completely closed, the engaging portion 44 a is fitted into the concave groove 47 and is clamped by the clamp tool 46.

  When the engaging portion 44a is clamped by the clamp tool 46, the closed state of the rotating frame body 45 is maintained, and further, the sensor unit 2 is connected to the rotating frame body 45 via the unit pressing spring 19. The state of being pushed down is maintained. When the unit pressing spring 19 is bent, the unit support pin 22 hits the lower end of the long hole 51, and the unit support pin 21 hits the lower end of the cutout hole 52. In this state, the lower surfaces of the first probe 7 and the second probe 8, that is, the probe surfaces protrude from the lower surface of the magnet block 31 by a predetermined amount.

  The protruding amounts of the first probe 7 and the second probe 8 are the holding state of the first probe 7 with respect to the first probe holder 5 and the first amount with respect to the second probe holder 6. It is determined by the holding state of the two probes 8.

  The relationship between the first probe 7, the second probe 8, the first probe holder 5, and the second probe holder 6 is not measured on the site or with appropriate tools. In order to set the optimum state, a jig is used.

  7A and 7B are diagrams for mounting the first probe 7 and the second probe 8 on the first probe holder 5 and the second probe holder 6, respectively. The jig 61 is shown.

  The jig 61 has a base plate 62, and the base plate 62 has the first probe 7 held by the first probe holder 5 and the second probe holder 6, and the first probe 7. Counterbore holes 63, 63 that match the positional relationship with the second probe 8 are formed. The diameter of the counterbore holes 63, 63 is a diameter that the first probe 7 and the second probe 8 can easily enter. In addition, holder seats 65 are formed one step higher on the top surface of the base plate 62, and the first probe holder 5 and the second probe holder 6 are placed on the holder seats 65. It is supposed to do. In addition, the dimension between the upper surface of the holder receiving seat 65 and the bottom surface of the seating holes 63, 63 is determined by the first probe from the first probe holder 5 and the second probe holder 6. The amount of protrusion of the child 7 and the second probe 8 is obtained.

  Also, bolts 66 serving as legs are attached to the four corners of the base plate 62, and the convenience of workability is taken.

  When the first probe 7 and the second probe 8 are attached to the first probe holder 5 and the second probe holder 6 using the jig 61, the first probe The probe holder 5 and the second probe holder 6 are placed on the holder receiving seat 65, the probe holding holes 11 and 11 and the seating holes 63 and 63 are aligned, and the first The first probe 7 and the second probe 8 are dropped into the probe holding holes 11 and 11 and the sitting hole 63 and 63. At this time, the probe fixing bolt 15 is sufficiently loosened so that the first probe 7 and the second probe 8 can be moved freely.

  When the probe fixing bolt 15 is tightened in a state in which the first probe 7 and the second probe 8 are in contact with the bottom surfaces of the pocket holes 63, 63, the first probe is tightened. 7. The second probe 8 is fixed to the first probe holder 5 and the second probe holder 6, and the protruding amount of the first probe 7 and the second probe 8 is further increased. Is also set to a predetermined value.

  Next, a case where an ultrasonic flaw detection test is performed using the ultrasonic flaw detection apparatus will be described.

  In the ultrasonic flaw detector 1 shown in FIG. 1, the lower surface, that is, the surface shown in FIG. 2, is in contact with the flaw detection surface. Therefore, when inspecting a composite slab such as a bridge, the lower surface of the ultrasonic flaw detector 1 is brought into contact with the inspection site from below.

  The following description will be made assuming that the ultrasonic flaw detector 1 is installed on the inspection site from the upper side for ease of explanation.

  The sensor unit 2 is detached from the unit support 3, the lock shaft 44 is clamped by the clamp tool 46, and the rotating frame body 45 is closed (state shown in FIG. 6).

  The rubber grip 43 is held, and the inspection position and the center of the unit support 3 are aligned using the horizontal ruled lines 57 and the vertical ruled lines 58.

  In a state where the center of the unit support 3 and the inspection position coincide with each other, the knob 32 of each of the magnet blocks 31 is turned so that the four magnet blocks 31 are combined with the composite floor slab 30 (in FIG. The unit support 3 is fixed by adsorbing to a steel plate.

  The release lever 49 is pulled up to release the clamped state of the engaging portion 44a, and the rotating frame body 45 is rotated upward. A contact medium is applied to the examination site. The contact medium may be applied when the unit support 3 is fixed.

  With the sensor unit 2 tilted, the unit support pin 22 is inserted into the elongated hole 51, and then the sensor unit 2 is leveled and the unit support pin 21 is fitted into the notch hole 52. Let The lock plate 53 is slid to prevent the unit support pin 21 from being removed from the notch hole 52, and the lock bolt 55 is tightened to lock the lock plate 53.

  In this state, the lower surfaces of the first probe 7 and the second probe 8 are in contact with the surface of the composite floor slab 30, and the first probe 7 and the second probe 8 protrude. It has been pushed up by the amount. The unit support pin 22 is located in the middle of the long hole 51 and is in a floating state in which neither the upper end nor the lower end of the long hole 51 is in contact. Similarly, the unit support pin 21 is in a floating state. Further, in this state, in order to make the contact surfaces of the first probe 7 and the second probe 8 conform to the contact medium, the probe fixing bolt 15 is loosened, and the first probe 7 The probe fixing bolt 15 may be retightened after the second probe 8 is rotated and acclimated.

  When the rotating frame 45 is rotated in the closing direction, the spring holding shaft 17 from the shaft 38 is inserted into the slit hole 41, and the slide washer 18 abuts against the lever 39. Further, when the rotating frame 45 is rotated, similarly, the spring holding shaft 17 from the clamp tool 46 is inserted into the slit hole 41, and the slide washer 18 abuts against the lever 39.

  When the rotating frame 45 is completely closed and the engaging portion 44a is clamped by the clamp tool 46, the lever 39 is parallel to the longitudinal beam 33, and the unit pressing spring 19 is bent by a predetermined amount. It becomes a state. The repulsive force generated by the amount of bending of the unit pressing spring 19 becomes a force for pressing the first probe 7 and the second probe 8 against the composite floor slab 30.

  If the optimum value of the deflection amount of the unit pressing spring 19 is obtained in advance by experiments or the like, the optimum pressing force can always be obtained by loading the sensor unit 2 into the unit support 3. Even when waviness or the like is present on the surface of the composite floor slab 30, relative displacement of the first probe 7 and the second probe 8 is allowed by deformation of the universal coupling 23, and the first The first probe 7 and the second probe 8 can be brought into close contact with the surface of the composite floor slab 30.

  When the mounting of the sensor unit 2 is completed, the cables 26 and 27 are connected to the measuring device 4 and ultrasonic flaw detection is executed.

  When the ultrasonic flaw detection at one inspection position is completed, the rotating frame 45 is opened, the sensor unit 2 is removed, the unit support 3 is moved to the next inspection position, the above procedure is repeated, and the ultrasonic flaw detection is performed. Continue to execute.

  If the unit support 3 is prepared and the unit support 3 is installed at the next inspection position in a state where the ultrasonic inspection is performed at one inspection position, the ultrasonic inspection and the unit are performed. Installation of the support 3 can be executed in parallel, and the inspection time can be shortened.

  FIG. 8 shows a second embodiment. In the second embodiment, a wheel unit 71 is attached to the unit support 3 so that the unit support 3 can travel along the rail, and the unit support 3 is moved and installed. Is a simpler version.

  In FIG. 8, the unit support 3 is shown in a simplified manner. FIG. 8 shows a case where the lower surface of the composite floor slab 30 (see FIG. 3) is inspected, for example, and the ultrasonic flaw detector is installed on the lower surface of the composite floor slab 30 in an upward posture. In FIG. 8, the same components as those shown in FIG. 4 are denoted by the same reference numerals.

  Hereinafter, the wheel unit 71 will be described. The wheel unit 71 has a front wheel portion 72 and a rear wheel portion 73. Since the front wheel portion 72 and the rear wheel portion 73 have substantially the same structure, the front wheel portion 72 will be described below.

  The wheel unit 71 is stretched over the magnet block 31 in parallel with the second transverse beam 35 and the axle frame 74 is attached. The axle frame 74 is formed of a belt-like flat plate, and is formed into a substantially concave shape by bending both ends 74a of the flat plate at right angles to the traveling direction. The both end portions 74 a protrude from the side surface of the magnet block 31 to the side at least the height of the knob 32.

  An axle 75 penetrating the both end portions 74 a in the horizontal direction is provided, and the axle 75 is rotatably supported by the both end portions 74 a via a bearing block 76. The bearing block 76 is slidable in the vertical direction with respect to the both end portions 74a. Traveling wheels 77 are attached to both ends of the axle 75, and the traveling wheels 77 can travel along a rail 78 installed on the lower surface of the composite floor slab 30. The rail 78 may be installed in advance for ultrasonic flaw detection inspection, or may be temporarily attached by a detachable fixing means such as a magnet or a bolt when performing the inspection.

  A long hole 79 through which the shaft 55 a of the lock bolt 55 passes is formed in the axle frame 74, and the long hole 79 has a length sufficient to slide the lock plate 53. The knob 32 further extends from the upper surface (the lower surface in FIG. 8) of the vertical beam 33 in consideration of operability.

  Since the rear wheel portion 73 is not provided with the elongated hole 79 of the front wheel portion 72 in the axle frame 74 and the other structure is the same as that of the front wheel portion 72, the description thereof will be omitted.

  First, the rails 78 and 78 are installed on the lower surface of the composite floor slab 30. The rails 78 may be individually installed and the parallelism may be adjusted. However, as shown in FIG. 8, two required portions of the rails 78 and 78 are connected by a connecting rod 81, and the parallelism is previously set. You may make it obtain.

  The connecting rod 81 has a universal joint 82 in the middle, and the universal joint 82 is not displaced in the axial direction but can be bent. Accordingly, by connecting the two places of the rails 78 and 78 with the connecting rod 81, the rails 78 and 78 can be easily obtained in parallel, and there is a case where the bottom surface of the composite slab 30 has waviness or the like. The bending of the universal joint 82 can absorb the swell. The connecting rod 81 and the universal joint 82 may be detachable from the rail 78 in consideration of the transportability of the rail 78.

  The rail 78 is installed along the inspection location, and the position of the rail 78 is adjusted so that the inspection location is located on the center line of the rails 78 and 78. A scale for alignment may be provided for the rail 78.

  The rail 78, the wheel unit 71, and the like function as the ultrasonic flaw detector 1 moving means.

  Next, the unit support 3 is caused to ride on the rail 78. In addition, when making a rail ride, the traveling wheel 77 is fitted into the groove of the rail 78 from the end of the rail 78, or the rails 78 and 78 are notched at four positions so as to match the positional relationship of the traveling wheel 77. The traveling wheel 77 may be fitted into the groove of the rail 78 through the notch.

  In a state where the traveling wheel 77 is trained on the rail 78, the both end portions 74 a, that is, the axle frame 74 slides downward with respect to the bearing block 76 due to the weight of the unit support 3. The unit support 3 is displaced downward by the sliding amount of the bearing block 76. In the second embodiment, there are a case where the sensor unit 2 is previously mounted on the unit support 3 and a case where the sensor unit 2 is mounted on the unit support 3 after the unit support 3 is positioned. When mounted on the unit support 3 and the unit support 3 is displaced downward by its own weight, the attracting surface of the magnet block 31 is separated from the lower surface of the composite floor slab 30.

  In addition, when the unit support 3 is moved by setting the rails 78 and 78 so that the inspection point is on the center line of the rails 78 and 78, that is, The vertical center 9 (see FIG. 5) of the sensor unit 2 sequentially passes through the inspection location.

  First, the case where the unit support 3 is positioned alone and then the sensor unit 2 is mounted will be described.

  When the unit support 3 is run to the inspection position and the inspection position and the intersections of the horizontal ruled lines 57 and the vertical ruled lines 58 coincide with each other, the unit support 3 is lifted and the attracting surface of the magnet block 31 is moved. The abutment is brought into contact with the lower surface of the composite floor slab 30, and the knob 32 is further rotated to attract the magnet block 31 to the composite floor slab 30. When the scale is provided on the rail 78, the inspection position can be determined by reading the scale. In this case, the work of marking the inspection position on the composite floor slab 30 can be omitted.

  Next, the sensor unit 2 is mounted on the unit support 3. Since the mounting of the unit support 3 and the ultrasonic flaw detection by the first probe 7 and the second probe 8 are the same as described above, the description thereof will be omitted.

  In this embodiment, since the unit support 3 in a state where the sensor unit 2 is mounted is supported by the rail 78, the sensor unit 2 is not attached / detached every time inspection is performed, and the inspection is completed when the inspection is completed. 2 is mounted, the knob 32 is rotated, the attraction of the magnet block 31 is released, the ultrasonic flaw detector 1 is moved, the unit support 3 is positioned at the next inspection position, and the knob 32 is moved. The magnet block 31 may be attracted by rotating the. In this case, the work of attaching and detaching the sensor unit 2 with respect to the unit support 3 is omitted, so that workability is further improved.

  According to the second embodiment, the weight of the unit support 3 can be moved without burdening the operator, and the alignment can be performed only in the traveling direction, so that the burden of work is reduced and workability is improved.

  FIG. 9 shows a comparison between the case where an artificial defect is formed in the boundary layer of the composite floor slab and the operator holds the probe by hand and the inspection is performed using the ultrasonic flaw detector of the present embodiment. Show.

  FIG. 9A shows the inspection result when the operator holds the probe by hand and inspects it, and FIG. 9B shows the case where the inspection is performed using the ultrasonic flaw detector of the present embodiment. The test result is shown.

  As shown in the drawing, in the conventional method in which the operator holds the probe by hand and inspects, the inspection results vary greatly. In the case of inspection with the ultrasonic flaw detector of the present embodiment, the variation in the inspection result is extremely reduced and the signal output value is greatly increased, which shows the effect of the present embodiment.

  In the above embodiment, the magnet block 31 is shown as a fixing means for fixing the unit support 3 to the inspection surface. However, a vacuum chuck may be used. Moreover, although the two rails 78 were shown in the said Example, you may move the said unit support 3 in the state suspended from the rail with one rail.

  As described above, according to the present invention, the probe can be installed and maintained at the inspection position in a hands-free manner, and the contact pressure can be set to an optimum state, so that the burden on the operator is greatly reduced and the inspection state is reduced. Is stable and the inspection accuracy is improved.

DESCRIPTION OF SYMBOLS 1 Ultrasonic flaw detector 2 Sensor unit 3 Unit support 4 Measuring apparatus 5 1st probe holder 6 2nd probe holder 7 1st probe 8 2nd probe 17 Spring holding shaft 18 Slide washer 19 Unit press Spring 21 Unit support pin 22 Unit support pin 23 Swivel coupling 31 Magnet block 36 Main frame body 41 Slit hole 44 Lock shaft 45 Rotating frame body 46 Clamping tool 49 Release lever 53 Lock plate 54 Barb piece 56 Positioning guide plate 57 Horizontal ruler Writing line 58 Vertical ruled line 61 Jig 71 Wheel unit 72 Front wheel part 73 Rear wheel part 76 Bearing block 77 Traveling wheel 78 Rail 81 Connecting rod 82 Universal joint

Claims (9)

  An ultrasonic flaw detector having a sensor unit that holds an ultrasonic probe and a unit support that holds the sensor unit and can be fixed to an inspection surface, wherein the sensor unit is detachable from the unit support. An ultrasonic flaw detection method comprising: positioning a unit support from which the sensor unit has been removed at an inspection position; then mounting the sensor unit on the unit support and performing ultrasonic flaw detection. Flaw detection method.   The ultrasonic flaw detection method according to claim 1, wherein a plurality of the unit supports are provided, each of the plurality of unit supports is installed at an inspection position, and the sensor units are sequentially mounted on the unit support to perform ultrasonic flaw detection.   The ultrasonic flaw detection method according to claim 1, wherein the unit support includes moving means, and the ultrasonic wave flaw detection is performed by sequentially moving the unit support to change the inspection location.   A sensor unit that holds an ultrasonic probe, a unit support that holds the sensor unit and can be fixed to an inspection surface, and the sensor unit is detachable from the unit support. Sonic flaw detector.   The unit support has a main frame body having a space for housing the sensor unit, and a rotation frame body that is rotatably provided on the main frame body and opens and closes the main frame body. A unit pressing spring that is held by the unit support so as to be displaceable in a direction perpendicular to the inspection surface and that extends upward is provided. When the rotating frame is closed, the unit pressing spring is compressed to The ultrasonic flaw detector according to claim 4, wherein the ultrasonic probe is pressed against the inspection surface via a spring.   The sensor unit includes a first probe holder that holds a first probe that oscillates ultrasonic waves, and a second probe holder that holds a second probe that receives reflected ultrasonic waves. The ultrasonic flaw detector according to claim 4 or 5, wherein the first probe holder and the second probe holder are connected by a free coupling.   The ultrasonic flaw detector according to claim 4, 5 or 6, wherein the main frame body further includes a positioning guide plate, and a marking line indicating an inspection position is engraved on the positioning guide plate.   The ultrasonic flaw detector according to claim 4, claim 5, claim 6, or claim 7, wherein the main frame body includes a moving means and is movable along a rail attached to the inspection surface.   The rails are two rails, and at least two portions of the rails are connected by a connecting rod, the parallelism of the two rails is determined, and a universal joint is provided in the middle of the connecting rod, The ultrasonic flaw detector according to claim 8, which is bendable.

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