Pipe inspection instrument

Abstract

To provide a piping inspection instrument constituted so as to be capable of inspecting an inspection target pipe in a pipe group having a narrow gap.SOLUTION: A piping inspection instrument according to the present application includes a base material extending in a longitudinal direction, an inspection head having a probing surface for detecting a state of a pipe to be inspected and attached to the base material in a first posture along the longitudinal direction, an operation unit operated to change a posture of the inspection head from the first posture to a second posture inclined with respect to the longitudinal direction, and a coupling member extending from the operation unit in the longitudinal direction along the base material so as to be insertable into a pipe bundle together with the base material and coupled to the inspection head. The inspection head has a thickness that allows the inspection head to pass through the gap between the pipes adjacent to each other in the thickness direction in a state where the inspection head is in the first posture. The coupling member is configured to direct the probing surface toward a predetermined measurement position on the outer peripheral surface of the pipe to be inspected by being brought into the second posture in response to an operation on the operation unit.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a piping inspection instrument for inspecting the condition of a target pipe in a pipe group in which a plurality of pipes extending in a predetermined extension direction are arranged at intervals from one another. [Background technology]

[0002] Patent Document 1 discloses a piping inspection tool 300 shown in Fig. 13. This piping inspection tool 300 is used to inspect a tube group 310 used as a heat exchanger of a boiler. In Fig. 13, this tube group 310 has four tube rows 311 to 314 arranged at intervals in the left-right direction, and these tube rows 311 to 314 are each composed of a plurality of tubes 315 arranged at intervals in the up-down direction. Note that these tubes 315 extend in a direction perpendicular to the plane of the paper on which Fig. 13 is drawn.

[0003] 13, in pipe row 313, fifth pipe 315 from the top is set as inspection target pipe 316. Pipe inspection tool 300 is configured to be able to measure the wall thickness of inspection target pipe 316 using ultrasound. Specifically, pipe inspection tool 300 includes a handle 320 that is long in the vertical direction, and an inspection head 322 attached to the lower end of handle 320 by means of a pivot shaft 321. Inspection head 322 is able to pivot up and down around pivot shaft 321, but is elastically held in a position at a 45° downward angle by a torsion spring (not shown).

[0004] A recess 323 that is approximately complementary to the outer circumferential surface of the inspection target pipe 316 is formed on the tip surface of the inspection head 322. The inspection head 322 is configured to transmit ultrasonic waves to the outer circumferential surface of the inspection target pipe 316 that is fitted into this recess 323, and to output a signal corresponding to the reflected wave of this ultrasonic wave. Based on this signal, the wall thickness of the inspection target pipe 316 can be measured. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2009-222387 Summary of the Invention [Problem to be solved by the invention]

[0006] The left-right spacing between the tube rows 311-314 of the tube group 310 in Fig. 13 is wider than the thickness (the dimension in the left-right direction in Fig. 13) of the piping inspection tool 300 including the inspection head 322. Therefore, an operator can insert the piping inspection tool 300 from above into the gap between the tube rows 313, 314 and reach the inspection head 322.

[0007] However, depending on the performance required of the heat exchanger, it may be necessary to measure the wall thickness of a tube to be inspected in a tube bank in which the gaps between the tubes are narrowed. For example, a staggered tube bank as shown in Fig. 14 may be used in a heat exchanger. In the tube bank shown in Fig. 14, even-numbered tubes from the top are arranged between odd-numbered tubes from the top in a plan view, and the gaps in the tube bank in a plan view may be narrower than the gaps in the tube bank shown in Fig. 13. It is expected that the gaps in such a staggered tube bank will be too narrow to insert the piping inspection tool 300 from above.

[0008] The present disclosure aims to provide a piping inspection tool that enables inspection of the condition of a target pipe in a pipe bank with narrow gaps. [Means for solving the problem]

[0009] A piping inspection instrument according to one aspect of the present invention is used to inspect the condition of a target pipe in a pipe bank, which includes a plurality of pipes extending in a predetermined extension direction and spaced apart from one another. The piping inspection instrument includes a base extending in a predetermined longitudinal direction so as to be insertable into the pipe bank; an inspection head having a probe surface for detecting the condition of the target pipe and attached to the base in a first position along the longitudinal direction; a control unit operated to change the position of the inspection head; and a connecting member extending in the longitudinal direction from the control unit along the base so as to be insertable into the pipe bank together with the base and connected to the inspection head. When in the first position, the inspection head has a thickness that allows it to pass through gaps between adjacent pipes in a thickness direction perpendicular to the longitudinal direction of the base inserted into the pipe bank and the extension direction of the plurality of pipes. The connecting member is configured to orient the probe surface toward a predetermined measurement position on the outer circumferential surface of the target pipe by changing the inspection head to a second position tilted relative to the longitudinal direction in response to operation of the control unit.

[0010] With the above-described configuration, the operator can insert the inspection head into the pipe bundle in a first position along the longitudinal direction, rather than in a second position inclined relative to the longitudinal direction. In this first position, the inspection head has a thickness that allows it to pass through gaps between adjacent pipe bundles in the thickness direction, making it less likely to get caught on a pipe in the pipe bundle while the operator is inserting the piping inspection tool in the longitudinal direction.

[0011] The inspection head is equipped with a base material and a connecting member, which can be inserted longitudinally into the pipe bundle, allowing the operator to insert the piping inspection tool deeper and bring the inspection head to a predetermined depth for inspecting the pipe being inspected. When the operator operates the control unit in this state, the inspection head is tilted relative to the longitudinal direction and assumes a second position. In this second position, the inspection surface faces a predetermined measurement position on the pipe being inspected, allowing the operator to detect the condition of the pipe being inspected at this measurement position.

[0012] Because the inspection head in the second position is inclined with respect to the longitudinal direction, the thickness dimension of the inspection head in the second position is larger than the thickness dimension of the inspection head in the first position. Therefore, if the gap between the tube groups is narrow, it is expected that the inspection head cannot be inserted into the tube group while it is in the second position. However, when the operating unit is not operated, the inspection head is in the first position, which is aligned with the longitudinal direction of the base material and the connecting member. Because the thickness dimension of the inspection head in this state is relatively small, it is possible to insert the inspection head into a tube group with a narrow gap.

[0013] In the above-described configuration, the operating unit may be configured to displace the connecting member relative to the base material in the longitudinal direction in response to an operation on the operating unit. Also, the connecting member may be connected to the inspection head at a position separated in the thickness direction from a connection position of the base material to the inspection head.

[0014] In the above-described configuration, when the operating unit is operated, the connecting member is displaced relative to the substrate in the longitudinal direction. The force displacing the connecting member acts on the connecting portion between the connecting member and the inspection head. As a result, the connecting portion is displaced in the longitudinal direction. At this time, since the connecting portion is separated in the thickness direction from the connection position of the substrate to the inspection head, the connecting portion between the connecting member and the inspection head is displaced relative to the connection position of the substrate to the inspection head. This relative displacement causes a change in the posture of the inspection head. For example, when the connecting member is displaced relative to the substrate in the insertion direction, which is one of the longitudinal directions, the connecting portion between the connecting member and the inspection head is displaced in the insertion direction. This displacement causes the inspection head to tilt toward the substrate. When the connecting member is displaced relative to the substrate in the withdrawal direction, which is opposite to the insertion direction, the connecting portion between the connecting member and the inspection head is displaced in the withdrawal direction. This displacement causes the inspection head to tilt toward the connecting member.

[0015] In the above-described configuration, the inspection head may be configured to emit ultrasonic waves from the inspection surface. In this case, the piping inspection tool may further include a supply pipe through which a couplant flows to be supplied to the inspection surface. This supply pipe may extend along the base material and the connecting member at a position between the base material and the connecting member in the thickness direction and be connected to the inspection head. The inspection head may be configured to allow the couplant to pass through the interior of the inspection head and seep out onto the inspection surface.

[0016] In the above-described configuration, a couplant is supplied to the inspection surface through a supply pipe to facilitate the propagation of ultrasonic waves and reflected waves between the pipe to be inspected and the inspection surface. The supply pipe extends between the base material and the connecting member in the thickness direction and is connected to the inspection head, so that the thickness of the pipe inspection tool is not increased by the supply pipe.

[0017] The couplant supplied through the supply pipe passes through the interior of the inspection head and seeps onto the inspection surface, filling the space between the inspection surface and the pipe under inspection that it is in contact with, facilitating the propagation of ultrasonic waves from the inspection surface to the pipe under inspection and the reflected waves from the pipe to the inspection surface.

[0018] In the above-described configuration, the base material and the connecting member may be flexible so as to avoid pipes on the front side of the pipes to be inspected. The connecting member may be connected to the inspection head at a position separated in the thickness direction from a connection position of the base material to the inspection head. In this case, the operating unit may be configured to displace the connecting member in a withdrawal direction opposite to the insertion direction of the pipe inspection tool into the pipe group, thereby pulling the connection portion of the connecting member to the inspection head in the withdrawal direction, so that tension is generated in the connecting member in response to operation of the operating unit.

[0019] In a pipe bank with a staggered arrangement as shown in Figure 14, a pipe in front of the pipe to be inspected may be in the insertion path of the piping inspection tool into the pipe bank. In the above-described configuration, the base material and connecting member are flexible, so even if a pipe of the pipe bank is in the insertion path of the piping inspection tool, it can bend to avoid this pipe. This allows the operator to reach the inspection head to the depth position required to inspect the pipe to be inspected.

[0020] If the connecting member is flexible, and the connecting member buckles in response to operation of the operating unit, the posture of the inspection head will not change. To prevent this situation, in the above-described configuration, the operating unit is configured to displace the connecting member in a withdrawal direction opposite to the insertion direction of the piping inspection tool into the pipe bundle so that tension is generated in the connecting member in response to operation of the operating unit. As a result, the tension of the connecting member can be applied to the inspection head. Furthermore, since the connecting member is connected to the inspection head at a position separated in the thickness direction from the connection position of the base material to the inspection head, the inspection head can tilt toward the connecting member and assume the second posture in response to the tension acting on the connecting member.

[0021] In the above-described configuration, the base material and the connecting member may have flexible tip sections extending a predetermined length from the inspection head so as to bend along the outer circumferential surface of the inspection target pipe.

[0022] When the pipe inspection tool is inserted downward into a pipe bundle, as the base material and connecting member change from being extended longitudinally to conforming to the outer circumferential surface of the pipe under inspection, the inspection head displaces horizontally (thickness-wise) to enter the space below the pipe under inspection. The amount of this horizontal (thickness-wise) displacement increases as the shapes of the base material and connecting member more closely match the curved shape of the outer circumferential surface of the pipe under inspection, making it possible to orient the probing surface of the inspection head to a measurement position closer to a vertical plane containing the centerline of the pipe under inspection. Therefore, in the above-described configuration, the flexible tip sections of the base material and connecting member allow the base material and connecting member to conform to the outer circumferential surface of the pipe under inspection, allowing the inspection head to approach the measurement position.

[0023] In the above-described configuration, the operating unit may be configured to displace the connecting member in a withdrawal direction opposite to a direction in which the pipe inspection tool is inserted into the pipe bundle, so that tension is generated in the connecting member in response to operation of the operating unit. In this case, the pipe inspection tool may further include a tip restricting unit configured to restrict the tip section of the connecting member from moving away from the base material in the thickness direction while encouraging the connecting member to bend along the outer circumferential surface of the pipe to be inspected, with the tip section of the base material bent along the outer circumferential surface of the pipe to be inspected.

[0024] In the above-described configuration, the tip section of the connecting member is flexible, so force must be transmitted to the inspection head without buckling the connecting member. Therefore, the operating unit is configured to displace the connecting member in a withdrawal direction opposite to the insertion direction of the pipe inspection tool into the pipe bundle so that tension is generated in the connecting member in response to operation of the operating unit. However, the tension acting on the connecting member causes the connecting member to attempt to straighten. In this case, the connecting member may straighten even though the base material is bent to fit the outer circumferential surface of the pipe under inspection. If the pipe inspection tool is inserted into the pipe bundle with the connecting member facing the pipe under inspection, the connecting member may come into contact with the pipe under inspection. This contact may prevent the inspection head from contacting the pipe under inspection. To avoid this situation, the pipe inspection tool in the above-described configuration uses a tip restricting portion to restrict the connecting member from moving away from the base material in the thickness direction. This allows the connecting member to bend along the base material.

[0025] In the above-described configuration, the tip restriction portion may have a plurality of tip restriction pieces attached to the base material at intervals in the longitudinal direction, and the number of these tip restriction pieces and the size of the interval between adjacent tip restriction pieces may be set to allow the base material and the connecting member to be shaped to fit the outer peripheral surface of the pipe to be inspected in the tip section.

[0026] In the above-described configuration, the multiple end restriction pieces are attached to the base material at intervals, allowing the base material and connecting member to bend between adjacent end restriction pieces. Therefore, if an appropriate number of end restriction pieces are provided in the end section at appropriate intervals, the base material and connecting member can extend in a shape close to an arc along the outer circumferential surface of the pipe being inspected in the end section. Note that if too few end restriction pieces are provided in the end section or if the spacing between adjacent end restriction pieces is too narrow, the curved or bent shape of the base material and connecting member may deviate from an arc shape. That is, when the piping inspection tool is inserted downward into a pipe bundle, the horizontal displacement of the inspection head due to operation of the operating part is reduced, making it difficult to orient the inspection head's scanning surface to a measurement position close to a vertical plane containing the centerline of the pipe being inspected. Alternatively, the end restriction pieces may come into contact with each other before the inspection head's scanning surface is oriented to the desired measurement position, inhibiting deformation of the base material and connecting member. The number of end restriction pieces and the spacing between adjacent end restriction pieces are determined taking these factors into consideration.

[0027] In the above-described configuration, the piping inspection instrument may further include a base end restricting portion provided in the base end section to restrict the base material and the connecting member from bending at or above a predetermined curvature in the base end section.

[0028] If the base end restricting portion were not provided, the tip end restricting portion would restrict the connecting member and base material from bending at an excessively large curvature in the tip section, but large curvature or bending of these elements would be tolerated in the base end section. In this case, even if an operator pushes the piping inspection tool into the pipe group to release the inspection head from getting caught on the pipe just before the pipe to be inspected, the operator's force is not transmitted to the inspection head, and only the base material and connecting member are curved or bent in the base end section. To avoid this situation, in the above-mentioned configuration, the base end restricting portion restricts the base material and connecting member from bending at a curvature greater than a predetermined curvature in the base end section. In this case, when the curvature or bending of the base material and connecting member in the base end section reaches the predetermined curvature, the force attempting to push the piping inspection tool into the pipe group is transmitted to the inspection head, and the inspection head is no longer caught on the pipe just before the pipe to be inspected.

[0029] In the above-described configuration, the base end restricting portion may have a plurality of base end restricting pieces attached to the base material at intervals in the longitudinal direction, and these base end restricting pieces may be configured to contact each other when the base material and the connecting member in the base end section have a predetermined curvature, thereby restricting bending or curvature beyond the predetermined curvature.

[0030] In the above-described configuration, the base material and the connecting member are allowed to bend or curve between adjacent base end restriction pieces in the longitudinal direction because the base material and the connecting member are spaced apart from one another in the longitudinal direction. As the base material and the connecting member bend or curve, the distance between adjacent base end restriction pieces gradually narrows, and when the curvature of the base material and the connecting portion reaches a predetermined value, the base end restriction pieces come into contact with one another. Further bending of the base material and the connecting member from this state is prevented by these base end restriction pieces.

[0031] In the above-described configuration, the tip restriction portion may be configured to allow the connecting member and the base material to bend in the tip section with a curvature greater than the predetermined curvature allowed by the base restriction portion.

[0032] In the above-described configuration, the connecting member and the base material in the proximal section only need to bend to an extent that they can avoid the pipe in front of the pipe to be inspected, whereas in the distal section they are required to have a shape that conforms to the outer surface of the pipe to be inspected. For this reason, the distal restriction section is configured to allow the connecting member and the base material in the distal section to bend at a curvature greater than the predetermined curvature allowed by the proximal restriction section.

[0033] In the above-described configuration, the base material and the connecting member may have a base section extending from the tip section toward the base end, and the base section may have higher rigidity than the tip section.

[0034] In the above-described configuration, the base material or the connecting member has a relatively high rigidity in the proximal section because the base material or the connecting member does not need to bend with as great a curvature as the distal section. As a result, by increasing the rigidity of the base material or the connecting member in the proximal section, the pipe inspection tool can be made robust.

[0035] In the above-described configuration, the piping inspection instrument may further include a bending restriction portion that restricts bending of the inspection head relative to the base material in a direction opposite to the position change from the first position to the second position.

[0036] In the above-described configuration, when the connecting member is displaced in the pull-out direction by operating the operating unit, the inspection head can change its position from the first position to the second position. However, when using a piping inspection tool on a staggered pipe group as shown in FIG. 14 , an external force may act on the inspection head while inserting the piping inspection tool into the pipe group, causing the inspection head to change position in the opposite direction to the change from the first position to the second position. If this external force allows the inspection head to bend and the operator holds the operating unit so as not to allow longitudinal displacement of the connecting member, the connecting member may be pulled with an excessively strong force. To avoid this situation, the piping inspection tool includes a bending restriction unit that restricts the inspection head from bending relative to the base material in the opposite direction to the change from the first position to the second position.

[0037] In the above-described configuration, the tip of the inspection head may be sharp.

[0038] In the above-described configuration, even if the inspection head comes into contact with the pipe in front of the pipe to be inspected while the worker is inserting the piping inspection tool into the pipe group, the tip of the inspection head is sharp, so the inspection head can be pushed deep into the pipe group without getting caught on the pipe. [Effects of the Invention]

[0039] The above-described piping inspection tool allows inspection of the condition of a target pipe in a pipe bank with tight clearances. [Brief explanation of the drawings]

[0040] [Figure 1] FIG. 1 is a perspective view of a piping inspection tool. [Figure 2] FIG. 2 is an enlarged cross-sectional view of the tip portion of the piping inspection tool. [Figure 3] FIG. 2 is an enlarged cross-sectional view of the tip portion of the piping inspection tool. [Figure 4] FIG. 1 is a perspective view of a piping inspection tool. [Figure 5] 1 is a schematic diagram of a piping inspection tool inserted into a staggered pipe bank. FIG. [Figure 6] 1 is a schematic diagram of a piping inspection tool inserted into a staggered pipe bank. FIG. [Figure 7] FIG. 2 is an enlarged cross-sectional view of the tip portion of the piping inspection tool. [Figure 8] 1 is a schematic diagram of a piping inspection tool inserted into a staggered pipe bank. FIG. [Figure 9] FIG. 10 is a schematic diagram of a tip portion of a piping inspection tool that is not provided with a tip restriction portion. [Figure 10] 1 is a schematic diagram of a tube bank consisting of tubes arranged in rows and columns. [Figure 11] FIG. 10 is a schematic diagram of another plumbing inspection tool. [Figure 12] FIG. 10 is a perspective view of another plumbing inspection instrument. [Figure 13] FIG. 1 is a side view of a conventional pipe inspection instrument. [Figure 14] FIG. 1 is a schematic diagram of a staggered tube bank. DETAILED DESCRIPTION OF THE INVENTION

[0041] (Configuration of piping inspection equipment) 1 is a schematic perspective view of a piping inspection tool 100 used to detect the wall thickness of a pipe to be inspected in a pipe group in which multiple pipes extending in a predetermined extension direction are arranged at intervals from one another. The piping inspection tool 100 has an elongated shape, and an operator can grasp the base end of the piping inspection tool 100 and insert the piping inspection tool 100 into the pipe group in the longitudinal direction of the piping inspection tool 100. In the following description, the direction from the base end to the tip end of the piping inspection tool 100 is referred to as the "insertion direction." The direction opposite to the insertion direction is referred to as the "removal direction."

[0042] The piping inspection tool 100 includes a grip portion 110 that forms the base end of the piping inspection tool 100, and base materials 121 and 122 that extend longitudinally from the grip portion 110. The base materials 121 and 122 are made of strip-shaped sheet material that are spaced apart from each other in a width direction perpendicular to the longitudinal direction, and in this embodiment, are flexible along their entire length. For example, the base materials 121 and 122 may be stainless steel sheets. The piping inspection tool 100 is inserted into a pipe bundle with the width direction of the base materials 121 and 122 spaced apart from each other aligned along the extension direction of the pipes in the pipe bundle. In the following description, the direction perpendicular to the width direction and the longitudinal direction will be referred to as the "thickness direction."

[0043] The gripping portion 110 is formed in a generally rectangular frame shape, and the tip portion 111 of the gripping portion 110 is composed of a trapezoidal thin plate that narrows in width in the insertion direction. The base ends of the substrates 121 and 122 are fixed to this tip portion 111. The inspection head 130 that comes into contact with the inspection target pipe when measuring the wall thickness of the inspection target pipe is fixed to the tip of the substrates 121 and 122. Note that the inspection head 130 shown in FIG. 1 is oriented along the longitudinal direction, and this orientation will be referred to as the "first orientation" in the following description.

[0044] The grip portion 110 has a pair of rail members 112, 113 extending in the pulling direction from a tip portion 111 of the grip portion 110. These rail members 112, 113 are spaced apart from each other in the width direction. A base end portion 114 of the grip portion 110 spans the width direction between the base ends of these rail members 112, 113. This base end portion 114 is a round bar-shaped portion having a thickness that can be gripped by a user, and both ends of the base end portion 114 are connected to the base ends of the rail members 112, 113.

[0045] A substantially rectangular frame-shaped operating unit 140 that is operated to change the posture of the inspection head 130 is attached to the rail members 112 and 113. The rail members 112 and 113 are configured to allow the operating unit 140 to be displaced a predetermined distance in the pull-out direction from the position shown in FIG. 1 . The space surrounded by the operating unit 140 is large enough for a user to insert their fingertip. Using this space, the user can hook their fingertip on a base end portion 141 of the operating unit 140 and displace the operating unit 140 in the pull-out direction along the rail members 112 and 113 so that the base end portion 141 of the operating unit 140 approaches the base end portion 114 of the grip portion 110.

[0046] A band-shaped connecting member 150 extends longitudinally from a tip portion 142 of the operating unit 140 and is connected to the inspection head 130 so that the displacement of the operating unit 140 can be transmitted to the inspection head 130 to change the posture of the inspection head 130. That is, the base end of the connecting member 150 is fixed to the tip portion 142 of the operating unit 140, and the tip of the connecting member 150 is fixed to the inspection head 130. In this embodiment, the connecting member 150 is flexible over its entire length and can be formed using, for example, a resin sheet material.

[0047] 2, the connecting member 150 extends at a position spaced apart from the base materials 121 and 122 in the thickness direction. The connection positions of the connecting member 150 and the base materials 121 and 122 relative to the inspection head 130 are spaced apart from each other in the thickness direction. In the following description, the direction in which the connecting member 150 is disposed relative to the base materials 121 and 122 is referred to as the "front direction." In the following description, the direction opposite to the "front direction" is referred to as the "rear direction."

[0048] The distance between the front surface of the connecting member 150 and the back surfaces of the base materials 121 and 122 is smaller than the dimension in the thickness direction of the inspection head 130 shown in Fig. 2. Therefore, if there is a gap large enough for the inspection head 130 shown in Fig. 2 to pass through, the connecting member 150 and the base materials 121 and 122 can also pass through this gap.

[0049] Because the base end of connecting member 150 is fixed to operating unit 140, when the user applies force to operating unit 140 in the pulling direction and the operating unit 140 is displaced in the pulling direction, connecting member 150 is pulled in the pulling direction and displaced in the pulling direction. At this time, base materials 121 and 122 are fixed to gripping unit 110 and do not displace in the longitudinal direction. Therefore, connecting member 150 can be displaced in the longitudinal direction relative to base materials 121 and 122.

[0050] The tension generated in the connecting member 150 by operating the operating unit 140 acts on the connecting portion between the connecting member 150 and the inspection head 130. That is, this tension acts on the inspection head 130 at a position spaced forward from the connecting portion between the substrates 121 and 122 and the inspection head 130. As a result, the front portion of the inspection head 130 is pulled in the pull-out direction, and the inspection head 130 assumes a posture inclined with respect to the longitudinal direction so that the front portion of the inspection head 130 is closer to the base end than the rear portion of the inspection head 130, as shown in FIG. 3. In the following description, the posture of the inspection head 130 shown in FIG. 3 will be referred to as the "second posture."

[0051] When the inspection head 130 is in the first position, the dimension in the thickness direction of the inspection head 130 is smaller than the gap between adjacent tubes in the tube bundle in the thickness direction. On the other hand, as the position of the inspection head 130 approaches the second position from the first position, the dimension in the thickness direction of the inspection head 130 gradually increases. Therefore, when the inspection head 130 is in the second position, the dimension in the thickness direction of the inspection head 130 may be so large that insertion of the inspection head 130 into the tube bundle is not permitted.

[0052] The inspection head 130 has a flaw detector 131 that emits ultrasonic waves and generates a signal that indicates the intensity of the reflected waves of the ultrasonic waves, and a holder 132 that holds the flaw detector 131. The tips of the connecting member 150 and the base materials 121, 122 are fixed to the base end portion of the holder 132. The tip of the holder 132 (i.e., the tip of the inspection head 130) has a pointed shape.

[0053] The flaw detector 131 has a substantially circular detection surface 133 that emits ultrasonic waves and detects reflected waves of the ultrasonic waves, and this detection surface 133 is exposed on the front side of the holding part 132. In the holding part 132, as shown in FIG. 1, an annular groove 134 is formed so as to be recessed along the outer periphery of this detection surface 133.

[0054] The detection surface 133 is the part that comes into contact with the outer circumferential surface of the pipe under inspection when measuring the wall thickness of the pipe under inspection, and when the flaw detector 131 emits ultrasonic waves while the detection surface 133 is in contact with the outer circumferential surface of the pipe under inspection, the ultrasonic waves and their reflected waves propagate between the detection surface 133 and the pipe under inspection. A contact medium is supplied to the detection surface 133 to suppress attenuation of the ultrasonic waves and the reflected waves during this propagation.

[0055] 2, a flexible supply pipe 135 extends along the substrates 121 and 122 between the connecting member 150 and the substrates 121 and 122 to supply the couplant to the inspection head 130. The tip of the supply pipe 135 is fixed to the base end of the holder 132. A flow path is formed inside the holder 132 so that the couplant supplied through the supply pipe 135 leaks out from the annular groove 134. The couplant leaking out from the annular groove 134 seeps onto the inspection surface 133 and fills the space between the inspection surface 133 and the outer circumferential surface of the pipe to be inspected, thereby suppressing the attenuation of ultrasonic waves and reflected waves.

[0056] As shown in Fig. 1, a tip restriction portion 160 is disposed in a tip section extending from the inspection head 130 over a predetermined length toward the base end. In this tip section, when an operator displaces the operation unit 140 toward the base end, the base materials 121, 122 and the connecting member 150 bend in the front direction as shown in Fig. 3. The tip section can be defined as the section in which the base materials 121, 122 and the connecting member 150 bend when the operator displaces the operation unit 140 maximally toward the base end from the position shown in Fig. 1.

[0057] The tip restriction portion 160 is provided to maintain a substantially constant distance in the thickness direction between the base materials 121, 122 and the connecting member 150 in the tip section, thereby curving or bending the connecting member 150 along the base materials 121, 122. Furthermore, the tip restriction portion 160 restricts the connecting member 150 and the base materials 121, 122 from bending with an excessively large curvature in the tip section.

[0058] The tip restriction portion 160 has a plurality of tip restriction pieces 161 arranged at intervals in the longitudinal direction of the base materials 121, 122. The intervals between adjacent tip restriction pieces 161 in the longitudinal direction are equal to each other. The number of tip restriction pieces 161 and the intervals between adjacent tip restriction pieces 161 are set so that the base materials 121, 122 and the connecting member 150 bend in the tip section in a shape that follows the outer circumferential surface of the pipe to be inspected.

[0059] Of these leading edge restriction pieces 161, the leading edge restriction piece 161 closest to the tip is spaced apart in the longitudinal direction from the inspection head 130. The distance between this leading edge restriction piece 161 and the inspection head 130 is approximately equal to the distance between adjacent leading edge restriction pieces 161 in the longitudinal direction. The base materials 121, 122 can bend between adjacent leading edge restriction pieces 161 and between the inspection head 130 and the leading edge restriction piece 161.

[0060] Each leading edge restriction piece 161 is formed from a plate-like member that is long in the width direction. Specifically, as shown in FIG. 1, leading edge restriction piece 161 has end portions 162, 163 fixed to base materials 121, 122 with screws, respectively, and a central portion 164 bent from these end portions 162, 163 toward the front side. When viewed in the longitudinal direction, central portion 164 has a generally C-shape that opens toward the rear side. Furthermore, the longitudinal dimension of central portion 164 is greater than the longitudinal dimensions of end portions 162, 163.

[0061] 2, the connecting member 150 and the supply pipe 135 are inserted in the longitudinal direction within the space surrounded by the central portion 164 of the tip restricting piece 161. The central portion 164 restricts the displacement of the connecting member 150 and the supply pipe 135 in the direction away from the base materials 121 and 122 in the thickness direction.

[0062] 3, the center portions 164 of the leading end restriction pieces 161 adjacent to each other in the longitudinal direction of the base materials 121 and 122 come into contact with each other. In this state, further curvature or bending of the leading end restriction pieces 161 of the connecting member 150, the supply pipe 135, and the base materials 121 and 122 between these leading end restriction pieces 161 can be restricted.

[0063] A bending restriction portion 166 is disposed on the rear side of the most distal end restriction piece 161, restricting the inspection head 130 from bending toward the rear. The bending restriction portion 166 has ends 167, 168 that sandwich the base materials 121, 122 in the thickness direction together with ends 162, 163 of the most distal end restriction piece 161, and a central portion 169 that bends from these ends 167, 168 toward the rear. The ends 167, 168 of the bending restriction portion 166 and the ends 162, 163 of the most distal end restriction piece 161 can be screwed together. As a result, the most distal end restriction piece 161 can be fixed to the base materials 121, 122 with high strength.

[0064] A central portion 169 of the bending restriction portion 166 is larger than the end portions 162, 163 in the longitudinal direction of the base materials 121, 122, and the tip portion of the central portion 169 is located close to the holding portion 132 of the inspection head 130. Therefore, when the inspection head 130 tries to bend rearward, the tip portion of the central portion 169 comes into contact with the holding portion 132 of the inspection head 130, and bending of the inspection head 130 rearward can be restricted.

[0065] In the base section extending toward the base end relative to the tip section, a base end restriction portion 170 is provided on the front side of the base materials 121, 122, as shown in FIG. 1 . The base end restriction portion 170 has a plurality of base end restriction pieces 171 arranged at intervals in the longitudinal direction of the base materials 121, 122. The base end restriction pieces 171 have the same shape and size as the tip end restriction piece 161 of the tip end restriction portion 160, and have end portions 162, 163 and a central portion 164. The end portions 162, 163 of the base end restriction piece 171 are fixed to the base materials 121, 122 with screws, respectively, in the same manner as the end portions 162, 163 of the tip end restriction piece 161. The connecting member 150 and the supply pipe 135 are inserted longitudinally through a space surrounded by the central portion 164 of the base end restriction piece 171.

[0066] When the connecting member 150 and the base materials 121, 122 are bent with a certain degree of curvature, the multiple base end restriction pieces 171 may come into contact with each other. When the multiple base end restriction pieces 171 are in this state, further curvature or bending of the connecting member 150 and the base materials 121, 122 is restricted.

[0067] Note that a cable (not shown) for the flaw detector 131 may also be extended in the same manner as the connecting member 150 and the supply pipe 135. That is, this cable may also be extended in the longitudinal direction of the base materials 121, 122 through the space surrounded by the base end limiting piece 171 or the central portion 164 of the tip end limiting piece 161. This cable may be used to transmit commands for instructing the flaw detector 131 to emit ultrasonic waves and signals generated by the flaw detector 131.

[0068] In this embodiment, the distance between adjacent base end restricting pieces 171 in the longitudinal direction and the distance between the most distal base end restricting piece 171 and the most proximal end restricting piece 161 are equal to the distance between adjacent tip end restricting pieces 161 in the longitudinal direction.

[0069] (Inspection using piping inspection equipment) The piping inspection instrument 100 can be used, for example, to measure the wall thickness of a pipe 202 to be inspected in a pipe bank 200 having a staggered arrangement as shown in Fig. 5. This pipe bank 200 has first to seventh pipe rows, and each tube row is composed of pipes 201 arranged at intervals in the vertical direction. In this embodiment, a method for measuring the wall thickness will be described for the case where the pipe 202 to be inspected is the second-highest pipe 201 in the central fourth pipe row.

[0070] The piping inspection tool 100 is inserted downward into the pipe group 200 from above. When viewed from this insertion direction, the rear portion of the fourth pipe row, which includes the pipe 202 to be inspected, overlaps with the front portion of the fifth pipe row, which is adjacent to the rear side of the fourth pipe row. Therefore, the pipe group 200 does not have a gap that would allow the piping inspection tool 100 to be inserted downward while maintaining a vertically straight state. Meanwhile, the gaps between the pipes 201 at the same height in the fifth pipe row and the third pipe row, which is in front of the fifth pipe row, are wider than the thickness of the inspection head 130 in the first position shown in FIG. 2 , and the inspection head 130 can be inserted into the gaps between these pipes 201.

[0071] While holding the piping inspection tool 100 above the pipe group 200, the worker hangs the tip of the piping inspection tool 100 into the gap between the uppermost pipes 201 of the third and fifth pipe rows. At this time, the worker holds the piping inspection tool 100 in an orientation in which the connecting member 150 faces the third pipe row and the base materials 121, 122 face the fifth pipe row. Then, the worker lowers the piping inspection tool 100 when the base materials 121, 122 are close to the uppermost pipe 201 of the fifth pipe row.

[0072] As the piping inspection tool 100 is lowered, the inspection head 130 at the tip (lower end) of the piping inspection tool 100 comes into contact with the back side portion of the uppermost pipe 201 in the fourth pipe row. At this time, because the tip (lower end) of the inspection head 130 has a pointed shape, when the worker further lowers the piping inspection tool 100, it can reach a position below the pipe 201 without getting caught on the pipe 201.

[0073] As the piping inspection tool 100 continues to descend, the inspection head 130 successively contacts the second-upper pipe 201 in the fifth pipe row and the second-upper pipe 201 in the fourth pipe row (i.e., the pipe under inspection 202). Then, as shown in FIG. 6, the inspection head 130 reaches a position diagonally below the pipe under inspection 202. At this time, the piping inspection tool 100, in the base end section, contacts the pipe under inspection 202 in the fourth pipe row, the uppermost pipe 201 in the fourth pipe row, the uppermost pipe 201 in the fifth pipe row, and the second-highest pipe 201 in the fifth pipe row.

[0074] In this state, the base materials 121, 122 and the connecting member 150 are flexible, and the base end restricting portion 170 allows the base materials 121, 122 and the connecting member 150 to bend or curve to a certain extent, so that the piping inspection instrument 100 can bend at the contact portion described above. That is, the piping inspection instrument 100 can bend toward the fifth tube row (i.e., toward the back side) at the contact portion with the tube 201 of the fourth tube row, and can bend toward the fourth tube row (i.e., toward the front side) at the contact portion with the tube 201 of the fifth tube row.

[0075] When the inspection head 130 reaches a position diagonally below the inspection target pipe 202, the operator displaces the operating unit 140 in the pull-out direction (i.e., upward). As a result, the connecting member 150 connected to the operating unit 140 is also pulled in the pull-out direction and displaced. At this time, the tension generated in the connecting member 150 acts on the front portion of the inspection head 130 to which the tip (i.e., the lower end) of the connecting member 150 is connected. Then, as shown in FIG. 7, the inspection head 130 assumes an inclined position in which the front portion of the inspection head 130 is pulled closer to the base end than the back portion of the inspection head 130.

[0076] At this time, the tip restriction piece 161 is attached to the front side of the base materials 121, 122, and as the front side portion of the inspection head 130 is pulled toward the base end, the gap between the tip-most tip restriction piece 161 and the front side portion of the inspection head 130 narrows. As this gap narrows, the base materials 121, 122 bend at a position corresponding to this gap. Then, when the tip-most tip restriction piece 161 comes into contact with the inspection head 130, this gap disappears, and the curvature or bending of the base materials 121, 122 at this gap is restricted.

[0077] When the operator further displaces the operating unit 140 in the pull-out direction, the force of the operator is transmitted through the connecting member 150 to the inspection head 130 and the tip-most tip restriction piece 161 that is in contact with the inspection head 130. Then, the front side portion of the inspection head 130 and the tip-most tip restriction piece 161 are pulled in the pull-out direction. As a result, as shown in FIG. 3 , the gap between the tip-most tip restriction piece 161 and the tip restriction piece 161 above it (the base end side) narrows, and the base materials 121 and 122 bend in this gap. As a result, the posture of the inspection head 130 is changed. Then, when these tip restriction pieces 161 come into contact with each other, the curvature or bending of the base materials 121 and 122 between them is restricted.

[0078] When the operator further displaces the operating part 140 in the pulling-out direction, the second leading end restriction piece 161 from the leading end and the third leading end restriction piece 161 from the leading end come into contact with each other on the front side of the base materials 121, 122. As a result, the deformation of the base materials 121, 122 increases, and the posture of the inspection head 130 also changes further.

[0079] In this way, as the operator displaces the operating part 140 in the pull-out direction, the gap between adjacent tip restriction pieces 161 in the longitudinal direction decreases, and the position where bending deformation of the base materials 121, 122 occurs in this gap shifts toward the base end. Then, when the operator displaces the operating part 140 in the pull-out direction to the maximum, the multiple tip restriction pieces 161 arranged in the tip section come into contact with each other.

[0080] After the inspection head 130 reaches a position diagonally below the inspection target pipe 202 and before the operator displaces the operation unit 140, the detection surface 133 of the flaw detector 131 faces forward. That is, the inspection head 130 is in a first position. Thereafter, when the operator displaces the operation unit 140 in the pull-out direction, the detection surface 133 faces diagonally upward, as shown in Figures 7 and 3. As a result, the inspection head 130 assumes a second position as shown in Figure 8, and the detection surface 133 faces an outer peripheral surface region of the inspection target pipe 202 that faces away from the operator.

[0081] As shown in FIG. 8 , simply by displacing the operating unit 140 in the pull-out direction, the detection surface 133 may come into contact with the pipe 202 under inspection. However, it is also possible that the detection surface 133 is separated from the pipe 202 under inspection while being tilted at an angle that faces the desired measurement position on the pipe 202 under inspection. In this case, the operator simply displaces the entire piping inspection instrument 100 in the pull-out direction. This allows the detection surface 133 to contact the pipe 202 under inspection at the desired measurement position. Note that the detection surface 133 shown in FIG. 8 is in contact with the pipe 202 under inspection at a position diagonally 45° below the horizontal plane at the height of the center of the pipe 202 under inspection. In such a case, the detection surface 133 shown in FIG. 8 can come into contact with a portion of the pipe 202 under inspection where a decrease in wall thickness is likely to be progressing, enabling measurement of the wall thickness of this portion.

[0082] Once contact is achieved between the sensing surface 133 and the pipe 202 under inspection, the operator supplies couplant to the inspection head 130 through the supply tube 135. This couplant leaks out of the annular groove 134 of the inspection head 130 and seeps onto the sensing surface 133. As a result, the gap between the sensing surface 133 and the pipe 202 under inspection can be filled with couplant.

[0083] The operator further performs an operation to cause the flaw detector 131 to emit ultrasonic waves, which propagate from the detection surface 133 to the pipe under inspection 202. During this propagation, the attenuation of the ultrasonic waves is suppressed by the contact medium. A portion of the ultrasonic waves propagates as reflected waves from the pipe under inspection 202 toward the detection surface 133. The detection surface 133 detects these reflected waves, and the flaw detector 131 generates a signal representing the intensity of these reflected waves. Based on this signal, the wall thickness of the pipe under inspection 202 at the measurement position (i.e., the contact position between the detection surface 133 and the pipe under inspection 202) can be measured.

[0084] The operator may gradually pull the entire pipe inspection instrument 100 upward while loosening the force being applied to the operating unit 140. As a result, the contact position of the detection surface 133 with the inspection target pipe 202 (i.e., the measurement position) may move upward in the circumferential direction of the inspection target pipe 202. If the flaw detector 131 continues to emit ultrasonic waves during this time, the inspection target pipe 202 may be scanned with ultrasonic waves over a predetermined circumferential length. In this case, data on the wall thickness of the inspection target pipe 202 over this circumferential length may be obtained.

[0085] In the piping inspection tool 100 shown in FIGS. 1 to 8, the inspection head 130 can be in the first position shown in FIG. 2 unless the operator operates the operating unit 140. When the inspection head 130 is in the first position, the dimension of the inspection head 130 in the thickness direction is small. This allows the operator to insert the inspection head 130 into a narrow gap in the pipe bank 200. Furthermore, at this time, the dimension of the connecting member 150 and the base materials 121 and 122 in the thickness direction is smaller than the dimension of the inspection head 130 in the thickness direction in the first position. This allows the inspection head 130 to pass through a gap in the pipe bank 200, and therefore the connecting member 150 and the base materials 121 and 122 can also pass through this gap.

[0086] Before reaching the desired depth position in the pipe bank 200, the inspection head 130 may come into contact with the pipe 201 just before the pipe 202 to be inspected. At this time, the tip of the inspection head 130 is not flat, but is pointed in the longitudinal direction of the piping inspection tool 100, so that the tip is unlikely to rest on the pipe 201. Therefore, the inspection head 130 can move further inward without getting caught on the pipe just before the pipe 202 to be inspected.

[0087] Even if the inspection head 130 gets caught on the pipe 201 just before the inspection target pipe 202, the operator can resolve this situation by further pushing the pipe inspection tool 100 deeper into the pipe group 200 as follows. That is, when the inspection head 130 is pushed deeper while it is caught on the pipe 201, the connecting member 150 and the base materials 121 and 122 bend. When the curvature of the connecting member 150 and the base materials 121 and 122 becomes large enough, the base end restriction pieces 171, the tip end restriction pieces 161, and the inspection head 130 may come into contact with each other. In this state, when the operator further pushes the pipe inspection tool 100, the connecting member 150 and the base materials 121 and 122 do not further bend or curve, and the force of the operator is transmitted to the inspection head 130 through the base end restriction pieces 171 and the tip end restriction pieces 161, which are in contact with each other. This allows the operator to push the inspection head 130 deep into the tube group 200.

[0088] When the inspection head 130 comes into contact with a tube 201 of the tube group 200, the posture of the inspection head 130 may change to some extent. However, the posture change in which the inspection head 130 tries to bend toward the rear side relative to the base materials 121, 122 can be restricted by the contact between the bending restricting portion 166 and the inspection head 130.

[0089] If bending of the inspection head 130 toward the rear side were permitted, the tip of the connecting member 150 could be pulled by the inspection head 130 while the base end of the connecting member 150 was fixed to the operation unit 140. As a result, an excessively large tension could be applied to the connecting member 150. On the other hand, if bending of the inspection head 130 toward the rear side is restricted by contact between the bending restricting portion 166 and the inspection head 130, such a large tension would be less likely to be applied to the connecting member 150.

[0090] When the inspection head 130 is inserted deeply into the pipe group 200, the distal and / or proximal sections of the pipe inspection tool 100 may come into contact with the pipe 201 located just before the pipe 202 to be inspected. When the pipe group 200 has a staggered configuration as shown in FIG. 6 , the distal and / or proximal sections of the pipe inspection tool 100 are not permitted to maintain a straight longitudinal extension. However, the base materials 121 and 122 and the connecting member 150 are flexible, and the proximal and distal restricting portions 170 and 160 allow the base materials 121 and 122 and the connecting member 150 to bend to some extent. Therefore, the distal and / or proximal sections of the pipe inspection tool 100 may extend in a meandering manner along the longitudinal direction to avoid the pipe 201 located just before the pipe 202 to be inspected. Therefore, the operator can bring the inspection head 130 to a depth position for inspecting the wall thickness of the inspection target pipe 202 in the pipe bank 200 having a staggered arrangement structure as shown in FIG.

[0091] A supply pipe 135 for supplying a contact medium to the inspection head 130 extends between the base materials 121, 122 and the connecting member 150. Therefore, the supply pipe 135 does not get caught on the pipe 201 in front of the inspection target pipe 202 until the inspection head 130 reaches the depth position for inspecting the wall thickness of the inspection target pipe 202.

[0092] After the inspection head 130 reaches this depth, the operator displaces the operating unit 140 in the withdrawal direction, causing the base materials 121, 122 and the tip sections of the connecting member 150 to bend to fit the outer circumferential surface of the pipe 202 under inspection, as shown in FIG. 8 . The inspection head 130 can then come into contact with the pipe 202 under inspection, as shown in FIG. 8 . Note that the closer the curved or bent shapes of the base materials 121, 122 and the connecting member 150 are to the curved shape of the outer circumferential surface of the pipe 202 under inspection, the closer the inspection head 130 can come into contact with the pipe 202 under inspection at a position closer to a vertical plane encompassing the center of the pipe 202 under inspection. Therefore, the number and spacing of the tip restriction pieces 161 are preferably set so that the base materials 121, 122 and the connecting member 150 can bend to fit the curved shape of the outer circumferential surface of the pipe 202 under inspection.

[0093] If the tip restricting portion 160 were not provided, the connecting member 150 would tend to extend straight due to the tension acting on the connecting member 150, as shown in Fig. 9. At this time, a portion of the connecting member 150 is pulled out from the tube group 200 by operating the operating portion 140, and the length of the base materials 121, 122 within the tube group 200 becomes longer than the length of the connecting member 150 within the tube group 200. For this reason, the base materials 121, 122 may become loose, as shown in Fig. 9.

[0094] If the base materials 121 and 122 are in a slack state while the connecting member 150 is stretched straight, the connecting member 150 may be displaced relatively from the base materials 121 and 122 in the thickness direction (i.e., toward the pipe 202 under inspection). As a result, the connecting member 150 may come into strong contact with the pipe 202 under inspection before the inspection head 130 comes into contact with the pipe 202 under inspection. Then, the contact of the connecting member 150 with the pipe 202 under inspection may prevent the inspection head 130 from contacting the pipe 202 under inspection.

[0095] On the other hand, if the tip restricting portion 160 is provided, the relative displacement of the connecting member 150 in the direction away from the base materials 121, 122 is restricted by the central portion 164 of the tip restricting piece 161. As a result, even if the operator operates the operating portion 140, the distance between the base materials 121, 122 and the connecting member 150 can be kept substantially constant over the entire length of the tip section, as shown in FIG.

[0096] 3, the curved or bent tip section of the connecting member 150 is located on the inner periphery side of the base materials 121, 122. Therefore, the length of the connecting member 150 in the curved or bent tip section is shorter than the length of the base materials 121, 122 in this tip section. The difference between these lengths corresponds to the amount of displacement of the operating unit 140 in the pulling direction.

[0097] In the piping inspection tool 100 shown in FIG. 1 , the spacing between adjacent base end restriction pieces 171 in the longitudinal direction of the base materials 121, 122 is equal to the spacing between adjacent tip end restriction pieces 161 in the longitudinal direction. However, the spacing between these base end restriction pieces 171 may be narrower than the spacing between these tip end restriction pieces 161 for the following reason. That is, in the tip section where the tip end restriction pieces 161 are arranged, the piping inspection tool 100 needs to bend with a relatively large curvature in response to operation of the operating unit 140. On the other hand, the base section where the base end restriction pieces 171 are arranged only needs to bend to an extent that it can avoid the inspection target pipe 202, and does not need to bend with as large a curvature as the tip section. For this reason, the spacing between the base end restriction pieces 171 may be relatively narrow.

[0098] Arranging the base end restriction pieces 171 at close intervals can be advantageous in the following respects. That is, the operator can push the piping inspection tool 100 into the pipe group 200 while the inspection head 130 is caught on the pipe 201 just before the inspection target pipe 202. At this time, the narrower the interval between the base end restriction pieces 171, the less the pushing distance of the piping inspection tool 100 until the base end restriction pieces 171 come into contact with each other. That is, the amount of pushing of the piping inspection tool 100 into the pipe group 200 to release the inspection head 130 from being caught on the pipe 201 can be reduced by narrowing the interval between the base end restriction pieces 171.

[0099] The piping inspection tool 100 can be used not only to measure the wall thickness of a staggered pipe bank 200, but also to measure the wall thickness of a target pipe 202 in a pipe bank 200 consisting of a plurality of pipes 201 arranged in a matrix as shown in Fig. 10. If the dimension in the thickness direction of the inspection head 130 in the first position is smaller than the gap between adjacent pipes 201 in the thickness direction, the operator can insert the piping inspection tool 100 into the pipe bank 200.

[0100] 10 , the pipe inspection instrument 100 does not need to bend in the base section. Therefore, the base materials 121, 122 and / or the connecting member 150 may have higher rigidity in the base section than in the tip section. In this case, the pipe inspection instrument 100 can be made more robust due to the increased rigidity in the base section.

[0101] If the rigidity of the base members 121, 122 and / or the connecting member 150 in the base section is increased to such an extent that they do not bend in the base section, it is not necessary to provide the base end restricting portion 170. This reduces the number of parts in the piping inspection instrument 100.

[0102] In the piping inspection instrument 100 of FIG. 1, the connecting member 150 is made of a strip-shaped film sheet. To prevent high tension from acting on the connecting member 150, the piping inspection instrument 100 is provided with a bend restricting portion 166, as shown in FIG. 4. However, if the connecting member 150 has a high enough strength to restrict the inspection head 130 from bending backward without breaking, the bend restricting portion 166 may be omitted. Alternatively, the bend restricting portion 166 may be omitted if the connecting member 150 is made of a material that can elastically stretch as the inspection head 130 bends backward.

[0103] The base materials 121 and 122 may have high rigidity along their entire length. In this case, the piping inspection instrument 100 may be configured as shown in FIG. 11(a). In the piping inspection instrument 100 of FIG. 11(a), the tips of the base materials 121 and 122 are attached to a pivot shaft 180 provided on the inspection head 130. The tip of the connecting member 150 is attached to the inspection head 130 at a position spaced from the base materials 121 and 122 toward the front side. As shown in FIG. 11(b), when the connecting member 150 is displaced in the pull-out direction, the inspection head 130 pivots upward about the pivot shaft 180, thereby changing its position.

[0104] In the piping inspection tool 100 shown in Fig. 1, the connection positions of the substrates 121, 122 relative to the inspection head 130 may be displaced in the front direction as the substrates 121, 122 are curved or bent. On the other hand, in the piping inspection tool 100 shown in Fig. 11, the connection positions of the substrates 121, 122 relative to the inspection head 130 do not change. The flaw detector 131 may be provided at a position close to the tip of the inspection head 130 so that the detection surface 133 can come into contact with the inspection target pipe 202 even without such displacement.

[0105] 11, the positional relationship in the thickness direction between the base materials 121, 122 and the connecting member 150 can be approximately constant before and after the connecting member 150 is displaced in the pull-out direction. Therefore, the piping inspection instrument 100 of FIG. 11 does not need to be provided with the tip restricting portion 160. As a result, the number of parts of the piping inspection instrument 100 can be reduced.

[0106] If the connecting member 150 is flexible, attempting to displace the connecting member 150 in the insertion direction will cause the connecting member 150 to buckle, making it difficult to transmit force to the inspection head 130. Therefore, if the connecting member 150 is flexible, it is necessary to use the operating unit 140 to pull the connecting member 150 in the withdrawal direction, causing the tension generated in the connecting member 150 to change the posture of the inspection head 130. On the other hand, if the connecting member 150 has high rigidity, as in the pipe inspection instrument 100 of FIG. 11 , the problem of buckling of the connecting member 150 is unlikely to occur. Therefore, the pipe inspection instrument 100 of FIG. 11 may be configured so that the connecting member 150 is displaced in the insertion direction in response to operation of the operating unit 140. In this case, if the bending restriction unit 166 is removed from the pipe inspection instrument 100, the inspection head 130 can be tilted rearward relative to the longitudinal direction.

[0107] In the pipe inspection tool 100 of Fig. 1, the connecting member 150 is made of a strip-shaped sheet material. Alternatively, the connecting member 150 may be made of a string-shaped material. The pipe inspection tool 100 of Fig. 1 also has two base materials 121 and 122. However, instead of these base materials 121 and 122, a single wide sheet material, base material 123, may be used, as shown in Fig. 12.

[0108] 1, the tip of the inspection head 130 has a pointed shape in the longitudinal direction. However, the tip of the inspection head 130 may be flat as long as there is no risk of the inspection head 130 getting caught on the pipes 201 of the pipe group 200 when the piping inspection tool 100 is inserted into the pipe group 200.

[0109] 1 to 13, the inspection head 130 is configured to emit ultrasonic waves from the inspection surface 133. Alternatively, the inspection surface 133 of the inspection head 130 may be configured to generate eddy currents in the pipe 202 under inspection. The inspection head 130 may then be configured to detect changes in impedance associated with the eddy currents flowing through the pipe 202 under inspection. In this case, the condition of the pipe 202 under inspection can be inspected based on the changes in impedance. [Industrial Applicability]

[0110] The above-described piping inspection tool can be suitably used to inspect a target pipe in a pipe group in which a plurality of pipes extending in a predetermined extension direction are arranged at intervals from one another. [Explanation of symbols]

[0111] 100 Piping inspection equipment 121~123...Base material 130 Inspection head 133 Exploration surface 135··············Supply pipe 140......Operation section 150 Connecting member 160 Tip restriction part 161...Tip regulation piece 166········Bending restriction section 170 Base end restriction part 171... Base end regulation piece 200···················Pipe group 201 · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · 202 Pipe to be inspected

Claims

1. A piping inspection tool for inspecting the condition of a target pipe in a pipe group in which a plurality of pipes extending in a predetermined extension direction are arranged at intervals from each other, a base member extending in a predetermined longitudinal direction so as to be insertable into the tube bundle; an inspection head having an inspection surface for detecting a state of the inspection target pipe and attached to the base material in a first orientation along the longitudinal direction; an operating unit that is operated to change the posture of the inspection head; a connecting member that extends from the operation unit along the base material in the longitudinal direction so as to be insertable into the tube group together with the base material, and that is connected to the inspection head; the inspection head, when in the first posture, has a thickness that allows it to pass through gaps between adjacent tubes in a thickness direction perpendicular to the longitudinal direction of the substrate inserted into the tube group and the extension direction of the plurality of tubes, The connecting member is configured to orient the detection surface toward a predetermined measurement position on the outer peripheral surface of the pipe to be inspected by placing the inspection head in a second position inclined with respect to the longitudinal direction in response to an operation on the operating unit.

2. the operating unit is configured to displace the connecting member relative to the base material in the longitudinal direction in response to an operation on the operating unit, The piping inspection tool according to claim 1 , wherein the connecting member is connected to the inspection head at a position spaced apart in the thickness direction from a connection position of the base material to the inspection head.

3. the inspection head is configured to emit ultrasonic waves from the inspection surface, The piping inspection tool further includes a supply pipe through which a couplant flows to be supplied to the inspection surface, the supply pipe extends along the base material and the connecting member at a position between the base material and the connecting member in the thickness direction and is connected to the inspection head; 3. The plumbing inspection tool of claim 2, wherein the inspection head is configured to allow the couplant to permeate through the interior of the inspection head and onto the inspection surface.

4. the base material and the connecting member have flexibility so as to be able to avoid a pipe on a front side of the inspection target pipe; the connecting member is connected to the inspection head at a position spaced apart in the thickness direction from a connection position of the substrate to the inspection head, 2. The piping inspection tool according to claim 1, wherein the operating unit is configured to displace the connecting member in a withdrawal direction opposite to an insertion direction of the piping inspection tool into the pipe group, thereby pulling the connection portion of the connecting member relative to the inspection head in the withdrawal direction, so that tension is generated in the connecting member in response to operation of the operating unit.

5. 2. The piping inspection tool according to claim 1, wherein the base material and the connecting member have flexible tip sections extending a predetermined length from the inspection head so as to bend along the outer circumferential surface of the pipe to be inspected.

6. the operating unit is configured to displace the connecting member in a withdrawal direction opposite to an insertion direction of the piping inspection tool into the pipe group so that tension is generated in the connecting member in response to an operation of the operating unit, 6. The piping inspection tool according to claim 5, further comprising a tip restricting portion configured to restrict the tip section of the connecting member from moving away from the base material in the thickness direction while encouraging the connecting member to bend along the base material when the tip section of the base material is bent along the outer peripheral surface of the pipe to be inspected.

7. the leading end restriction portion has a plurality of leading end restriction pieces attached to the base material at intervals in the longitudinal direction, 7. The piping inspection tool of claim 6, wherein the number of the plurality of tip restriction pieces and the size of the spacing between adjacent tip restriction pieces are set to allow the base material and the connecting member to assume a shape that conforms to the outer peripheral surface of the pipe to be inspected in the tip section.

8. the base material and the connecting member have flexibility in a base end section extending from the tip end section to a base end side so as to be able to avoid a pipe on a front side of the inspection target pipe, The piping inspection tool according to claim 6, further comprising a base end restricting portion provided in the base end section to restrict the base material and the connecting member from bending at the base end section to a curvature greater than a predetermined value.

9. the base end restriction portion has a plurality of base end restriction pieces attached to the base material at intervals in the longitudinal direction, 9. The piping inspection tool of claim 8, wherein the plurality of base end restricting pieces are configured to contact each other when the curvature of the base material and the connecting member in the base end section is the predetermined curvature, thereby restricting curvature or bending beyond the predetermined curvature.

10. 9. The piping inspection tool according to claim 8, wherein the tip end restriction portion is configured to allow the connecting member and the base material to bend in the tip section with a curvature greater than the predetermined curvature allowed by the base end restriction portion.

11. The piping inspection tool according to claim 4 or 6, further comprising a bending restriction portion that restricts bending of the inspection head relative to the base material in a direction opposite to the position change from the first position to the second position.

Images