Pipe inspection probe

Abstract

To provide a pipe inspection probe having an improved property of insertion into the inside of a pipe with a small diameter and a small bend radius.SOLUTION: A pipe inspection probe for inspecting a pipe from its inside includes: a first sensor holder in which a plurality of first sensors capable of transmitting and receiving ultrasonic waves are peripherally arranged apart from each other in one sensor array; a second sensor holder in which a plurality of second sensors capable of transmitting and receiving the ultrasonic waves are peripherally arranged apart from each other in the one sensor array; and a flexible member having predetermined torsional rigidity, which connects the first and second sensor holders in a manner to array them in an axial direction of the pipe inspection probe.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] SUMMARY The present disclosure relates to a pipe inspection probe for inspecting a pipe from inside the pipe. [Background technology]

[0002] Conventionally, ultrasonic inspection methods and eddy current inspection methods have been known as methods for non-destructively inspecting the presence or absence of damage, such as thinning and fatigue cracks, in pipes such as heat transfer tubes of a boiler. In these methods, a pipe inspection probe is attached to the front end of a cable or the like, and the cable is pushed into the inside of the pipe to insert the pipe inspection probe into the inside of the pipe. Patent Document 1 discloses that a cable guide including a rotatably supported roller is provided on the cable to improve the ease of inserting the cable into the inside of the pipe. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2023-104397 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, in the technology described in Patent Document 1, it is necessary to rotate the sensor part of the pipe inspection probe, which makes the device complicated and increases the inspection time. In addition, the technology described in Patent Document 1 also discloses that a plurality of sensor parts each having sensors arranged at different positions in the circumferential direction are connected by a rotating shaft so that the sensor part does not need to be rotated. However, in a pipe having a small diameter and a curved part with a small bending radius, the entire length of the sensor part is long and the range of bending radii that the rotating shaft can handle is narrow, so that the pipe inspection probe gets stuck at the curved part. Even if the sensor parts are connected to each other without using a rotating shaft so that the pipe inspection probe can easily pass through the curved part, the flexible shaft may twist and the sensor parts may rotate relative to each other, causing a part of the pipe in the circumferential direction to fall outside the inspection range. Here, the small diameter refers to an inner diameter of the pipe of about 20 to 40 mm, and the small bending radius refers to a pipe with a bending radius R of 35 mm or less.

[0005] The present disclosure has been made in consideration of the above-mentioned problems, and aims to provide a pipe inspection probe that can improve insertability into a pipe with a small diameter and a small bending radius. [Means for solving the problem]

[0006] In order to achieve the above-mentioned object, a piping inspection probe according to the present disclosure is a piping inspection probe for inspecting a piping from inside the piping, and comprises a first sensor holder in which a plurality of first sensors capable of emitting and receiving ultrasonic waves are arranged in a sensor row spaced apart from each other in the circumferential direction, a second sensor holder in which a plurality of second sensors capable of emitting and receiving ultrasonic waves are arranged in a sensor row spaced apart from each other in the circumferential direction, and a flexible member having a predetermined torsional rigidity that connects the first sensor holder and the second sensor holder so that they are aligned in the axial direction of the piping inspection probe. Effect of the Invention

[0007] The piping inspection probe of the present disclosure can improve insertability into a piping having a small diameter and a small bending radius. [Brief description of the drawings]

[0008] [Figure 1] 1 is a diagram illustrating a schematic configuration of a pipe inspection probe according to an embodiment; [Figure 2A] FIG. 4 is a diagram for explaining a layout of a first sensor according to an embodiment. [Figure 2B] FIG. 4 is a diagram for explaining a layout of a second sensor according to an embodiment. [Figure 2C] FIG. 13 is a diagram for explaining a layout of a third sensor according to an embodiment. [Figure 2D] FIG. 13 is a diagram for explaining a layout of a fourth sensor according to an embodiment. [Diagram 3] 4A and 4B are diagrams illustrating a cross-sectional shape of a flexible member according to an embodiment. [Figure 4A] 1A-1C are diagrams illustrating cross-sectional shapes of flexible members according to some embodiments. [Figure 4B] 1A-1C are diagrams illustrating cross-sectional shapes of flexible members according to some embodiments. [Figure 4C] 1A-1C are diagrams illustrating cross-sectional shapes of flexible members according to some embodiments. [Diagram 5] FIG. 13 is a diagram illustrating a schematic configuration of a piping inspection probe according to another embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Hereinafter, a pipe inspection probe according to an embodiment of the present disclosure will be described with reference to the drawings. The embodiment shows one aspect of the present disclosure, and does not limit the present disclosure. The embodiment can be arbitrarily modified within the scope of the technical idea of ​​the present disclosure.

[0010] (composition) FIG. 1 is a diagram illustrating a schematic configuration of a pipe inspection probe 1 according to an embodiment. As illustrated in FIG. 1, the pipe inspection probe 1 has an elongated shape. In the embodiment, the pipe inspection probe 1 is connected to one end of a long member 104 such as a cable or a tube via a joiner 102. The long member 104 is configured to be insertable into the pipe 50 to be inspected. The outer diameter of the long member 104 is smaller than the inner diameter of the pipe 50. The long member 104 is formed of, for example, metal or resin, and is configured to be bendable in accordance with the shape of the pipe line of the pipe 50 over its entire length.

[0011] The other end of the long member 104 is connected to a conveying device 106 arranged outside the pipe 50. The conveying device 106 is, for example, a pusher-type conveying device that pushes the long member 104 into the inside of the pipe 50 by human power or a machine. By pushing the long member 104 into the inside of the pipe 50 with the pusher-type conveying device, the long member 104 can be inserted into the inside of the pipe 50 and the pipe inspection probe 1 can be conveyed into the inside of the pipe 50. Note that the conveying device 106 may be a device other than the pusher-type conveying device, and may be, for example, a hydraulic conveying device that sends a water flow into the inside of the pipe 50.

[0012] In the present disclosure, the direction in which the axis O of the pipe inspection probe 1 extends is defined as the axial direction of the pipe inspection probe 1 (hereinafter, axial direction D1). In addition, one end of the pipe inspection probe 1 connected to the joiner 102 is defined as the base end 11a, and the direction from the base end 11a toward the tip end 11b in the axial direction D1 is defined as one side of the axial direction D1. In addition, the direction perpendicular to the axis O starting from the axis O is defined as the radial direction of the pipe inspection probe 1 (hereinafter, radial direction D2). The direction in which a circular trajectory described by rotating around the axis O extends is defined as the circumferential direction of the pipe inspection probe 1 (hereinafter, circumferential direction D3).

[0013] As shown in FIG. 1, the pipe inspection probe 1 includes a first sensor holder 2, a second sensor holder 4, and a flexible member 10 having a predetermined torsional rigidity. The predetermined torsional rigidity is determined based on the inspection ranges of eight sensors 3 described later, and is determined, for example, so that the inspection ranges of the sensors 3 adjacent to each other in the circumferential direction D3 do not overlap. In the embodiment illustrated in FIG. 1, the pipe inspection probe 1 further includes a third sensor holder 6, a fourth sensor holder 8, a tip guide 12, and an alignment jig 14. The tip guide 12, the first sensor holder 2, the second sensor holder 4, the third sensor holder 6, and the fourth sensor holder 8 are arranged in this order from one side of the axial direction D1. The tip guide 12 has a spherical shape and is connected to the first sensor holder 2 via a rod-shaped tip side shaft 13. This tip guide 12 includes the tip 11b of the pipe inspection probe 1. The fourth sensor holder 8 is connected to the joiner 102 via a rod-shaped base-end shaft 18. This base-end shaft 18 includes the base end 11a of the pipe inspection probe 1. Each of the tip-end shaft 13 and the base-end shaft 18 is, but is not limited to, a spring shaft, for example.

[0014] In one embodiment, when the length of the first sensor holder 2 in the radial direction D2 is L1 and the length of the first sensor holder 2 in the axial direction D1 is L2, L1≦L2≦1.2L1 is satisfied. Each of the second sensor holder 4, the third sensor holder 6, and the fourth sensor holder 8 has a size approximately equal to that of the first sensor holder 2.

[0015] In one embodiment, the pipe inspection probe 1 includes eight sensors 3 capable of transmitting and receiving ultrasonic waves. The sensors 3 are configured to be capable of acquiring a physical quantity related to the wall thickness of the pipe 50 (the time it takes for the transmitted ultrasonic waves to return to the sensors 3) as measurement data. Based on this measurement data, thinning of the inner surface 51 of the pipe 50 is detected. Each of the first sensor holder 2, the second sensor holder 4, the third sensor holder 6, and the fourth sensor holder 8 supports two of the eight sensors 3 (see FIGS. 2A to 2D).

[0016] In the following, the sensor 3 supported by the first sensor holder 2 will be referred to as the first sensor 23(3), the sensor 3 supported by the second sensor holder 4 will be referred to as the second sensor 43(3), the sensor 3 supported by the third sensor holder 6 will be referred to as the third sensor 63(3), and the sensor 3 supported by the fourth sensor holder 8 will be referred to as the fourth sensor 83(3).

[0017] As shown in Fig. 1, the two first sensors 23 are arranged in one sensor row. In the present disclosure, "arranged in one sensor row" means that the two sensors 3 at least partially overlap each other in the axial direction D1. In the embodiment illustrated in Fig. 1, the two first sensors 23 mostly or entirely overlap each other in the axial direction D1. Similarly, the two second sensors 43, the two third sensors 63, and the two fourth sensors 83 are each arranged in one sensor row.

[0018] FIG. 2A is a diagram for explaining the layout of the first sensor 23 according to one embodiment, as viewed from the axial direction D1. FIG. 2B is a diagram for explaining the layout of the second sensor 43 according to one embodiment, as viewed from the axial direction D1. FIG. 2C is a diagram for explaining the layout of the third sensor 63 according to one embodiment, as viewed from the axial direction D1. FIG. 2D is a diagram for explaining the layout of the fourth sensor 83 according to one embodiment, as viewed from the axial direction D1.

[0019] As shown in FIG. 2A, the two first sensors 23 are spaced apart from each other in the circumferential direction of the first sensor holder 2 (i.e., the circumferential direction D3). As shown in FIG. 2B, the two second sensors 43 are spaced apart from each other in the circumferential direction of the second sensor holder 4 (i.e., the circumferential direction D3). As shown in FIG. 2C, the two third sensors 63 are spaced apart from each other in the circumferential direction of the third sensor holder 6 (i.e., the circumferential direction D3). As shown in FIG. 2D, the two fourth sensors 83 are spaced apart from each other in the circumferential direction of the fourth sensor holder 8 (i.e., the circumferential direction D3).

[0020] 2A, the angular position θ of a virtual line X extending from the axis O so as to pass through the center position of one of the first sensors 23 is set to 0 degrees. This angular position θ increases as the line rotates in one direction in the circumferential direction D3 (clockwise on the paper surface of FIG. 2A) around the axis O as the center of rotation, and the angular position θ when the virtual line X makes one rotation is set to 360 degrees.

[0021] As shown in FIG. 2A, in one embodiment, the two first sensors 23 are located on opposite sides of the axis O. One of the first sensors 23 is disposed in the first sensor holder 2 so as to be located at an angular position θ of 0 degrees. The other of the first sensors 23 is disposed in the first sensor holder 2 so as to be located at an angular position θ of 180 degrees. More specifically, the center position of one of the first sensors 23 is located at an angular position θ of 0 degrees, and the center position of the other of the first sensors 23 is located at an angular position θ of 180 degrees. Note that the present disclosure is not limited to the layout of the first sensors 23 in the form exemplified in FIG. 2A. For example, one of the first sensors 23 may be located at an angular position θ of 0 degrees, and the other of the first sensors 23 may be located at an angular position θ of 90 degrees.

[0022] As shown in FIG. 2B, the two second sensors 43 are located on opposite sides of the axis O. One of the second sensors 43 is disposed in the second sensor holder 4 so as to be located at an angular position θ of 45 degrees. The other of the second sensors 43 is disposed in the second sensor holder 4 so as to be located at an angular position θ of 225 degrees. More specifically, the center position of one of the second sensors 43 is located at an angular position θ of 45 degrees, and the center position of the other of the second sensors 43 is located at an angular position θ of 225 degrees. Note that the present disclosure does not limit the layout of the second sensors 43 to the form exemplified in FIG. 2B.

[0023] As shown in FIG. 2C, the two third sensors 63 are located on opposite sides of the axis O. One third sensor 63 is disposed in the third sensor holder 6 so as to be located at an angular position θ of 90 degrees. The other third sensor 63 is disposed in the third sensor holder 6 so as to be located at an angular position θ of 270 degrees. More specifically, the center position of one third sensor 63 is located at an angular position θ of 90 degrees, and the center position of the other third sensor 63 is located at an angular position θ of 270 degrees. Note that the present disclosure does not limit the layout of the third sensor 63 to the form exemplified in FIG. 2C.

[0024] As shown in FIG. 2D, the two fourth sensors 83 are located on opposite sides of the axis O. One of the fourth sensors 83 is disposed in the fourth sensor holder 8 so as to be located at an angular position θ of 135 degrees. The other of the fourth sensors 83 is disposed in the fourth sensor holder 8 so as to be located at an angular position θ of 315 degrees. More specifically, the center position of one of the fourth sensors 83 is located at an angular position θ of 135 degrees, and the center position of the other of the fourth sensors 83 is located at an angular position θ of 315 degrees. Note that the present disclosure does not limit the layout of the fourth sensors 83 to the form exemplified in FIG. 2D.

[0025] As shown in FIGS. 2A and 2B, in one embodiment, the two first sensors 23 and the two second sensors 43 are offset from each other in the circumferential direction D3. Further, as shown in FIGS. 2A to 2D, the two first sensors 23, the two second sensors 43, the two third sensors 63, and the two fourth sensors 83 (that is, eight sensors 3) are offset from each other in the circumferential direction D3.

[0026] As illustrated in FIG. 1, in one embodiment, the flexible member 10 includes a first flexible member 15(10), a second flexible member 16(10), and a third flexible member 17(10). The first flexible member 15 connects the first sensor holder 2 and the second sensor holder 4 so as to be aligned in the axial direction D1. The second flexible member 16 connects the second sensor holder 4 and the third sensor holder 6 so as to be aligned in the axial direction D1. The third flexible member 17 connects the third sensor holder 6 and the fourth sensor holder 8 so as to be aligned in the axial direction D1. Note that each of the first flexible member 15, the second flexible member 16, and the third flexible member 17 may be separate from each other or may be integrally formed. Note that each of the first flexible member 15, the second flexible member 16, and the third flexible member 17 may have the same torsional rigidity as each other or may have different torsional rigidities from each other.

[0027] In one embodiment, the flexible member 10 is a corner spring. FIG. 3 is a diagram showing a cross-sectional shape of the flexible member 10 (corner spring) according to one embodiment. As shown in FIG. 3, the corner spring has a rectangular shape having a longitudinal shape along the radial direction D2 and a short-side shape along the axial direction D1 in cross section. In one embodiment, when the length of the cross-sectional shape of the flexible member 10 in the axial direction D1 is L3 and the length of the cross-sectional shape of the flexible member 10 in the radial direction D2 is L4, L3 < L4 < 2 × L3 is satisfied.

[0028] The aligning jig 14 is a jig for positioning the pipe inspection probe 1, which has been transported inside the pipe 50, at approximately the center of the pipe 50. In the embodiment illustrated in Fig. 1, the pipe inspection probe 1 includes a plurality of aligning jigs 14. The plurality of aligning jigs 14 include an aligning jig 14 provided on the tip-end shaft 13, an aligning jig 14 provided on the base-end shaft 18, an aligning jig 14 provided on the first flexible member 15, an aligning jig 14 provided on the second flexible member 16, and an aligning jig 14 provided on the third flexible member 17.

[0029] A specific configuration example of the aligning jig 14 will be described below using the aligning jig 14 provided on the first flexible member 15 as an example. The aligning jig 14 includes a main body 30 supported by the first flexible member 15, and a brush 32 extending outward in the radial direction D2 from the outer circumferential surface of the main body 30.

[0030] (Action and effect) The action and effect of the pipe inspection probe 1 according to one embodiment will be described. According to one embodiment, eight sensors 3 are distributed to each of the first sensor holder 2 to the fourth sensor holder 8, two sensors 3 being distributed. Therefore, the dimensions of each of the first sensor holder 2 to the fourth sensor holder 8 can be made smaller than a single sensor holder in which the eight sensors 3 are arranged together. In addition, since there is no need to make the sensor 3 smaller, it is also advantageous in that the flaw detection range of the sensor 3 is not reduced.

[0031] Furthermore, according to one embodiment, the first sensor holder 2 has a short dimension in the axial direction D1 by arranging two first sensors 23 in one sensor row. Similarly, the second sensor holder 4 to the fourth sensor holder 8 have a short dimension in the axial direction D1 by arranging two sensors 3 in one sensor row. Therefore, the first sensor holder 2 to the fourth sensor holder 8 can pass through even a curved portion with a small bending radius, and the insertability of the pipe inspection probe 1 into the inside of the pipe 50 can be improved.

[0032] According to one embodiment, the first sensor holder 2 is configured to satisfy L2≦1.2L1 (L1: radial length, L2: axial length), thereby shortening the length in the axial direction D1 compared to conventional sensor holders, and improving the insertability of the piping inspection probe 1 into the inside of the piping 50.

[0033] It is desirable that the flexible member 10 has a certain degree of bendability in order for the piping inspection probe 1 to pass through a curved portion of the piping 50. Also, it is desirable that the flexible member 10 has a certain degree of resistance to twisting (torsional rigidity) in order to prevent at least two of the first sensor holder 2 to the fourth sensor holder 8 from rotating relative to each other when the piping inspection probe is inserted, resulting in the eight sensors 3 being pulled out or leaking from their inspection ranges in the circumferential direction D3.

[0034] According to the findings of the present inventors, by using a square wire spring as the flexible member 10, the flexible member 10 can bend easily and twist with a certain degree. Therefore, according to one embodiment, since a square wire spring is used as the flexible member 10, it is possible to provide a pipe inspection probe 1 that is easy to insert into the pipe 50 and can widely inspect the pipe 50 in the circumferential direction D3. In some embodiments, the flexible member 10 is designed so that the deformation amount in the circumferential direction D3 (so-called twist angle) is within 15 degrees.

[0035] In one embodiment, the flexible member 10 is a square wire spring, but the present disclosure is not limited to this form. Each of Figs. 4A-4C is a diagram showing a cross-sectional shape of the flexible member 10 according to some embodiments. In some embodiments, the flexible member 10 is a spring member. The flexible member 10 illustrated in Fig. 4A has a cross-sectional shape of a trapezoid having a longitudinal shape along the radial direction D2. This trapezoidal cross-sectional shape has a long side on the outside of the radial direction D2 and a short side on the inside of the radial direction D2. The flexible member 10 illustrated in Fig. 4B has a cross-sectional shape of an ellipse having a longitudinal shape along the radial direction D2. This elliptical cross-sectional shape has a long axis extending along the radial direction D2. The flexible member 10 illustrated in Fig. 4C has a cross-sectional shape of a circle.

[0036] The resistance to twisting (torsional rigidity) of the spring member is affected by the second moment of area. According to some embodiments, by making the spring member less susceptible to twisting, the positions of the multiple sensors 3 are suppressed from shifting in the circumferential direction D3. In other words, the occurrence of missing or leaking in the inspection range of the multiple sensors 3 is suppressed. Therefore, the pipe inspection probe 1 can widely inspect the pipe 50 in the circumferential direction D3 from inside the pipe 50. Meanwhile, a spring member having a rectangular cross-sectional shape is more difficult to twist than a spring member having a square cross-sectional shape. Similarly, a spring member having an elliptical cross-sectional shape is more difficult to twist than a spring member having a circular cross-sectional shape. Therefore, according to the embodiment illustrated in FIG. 4A and FIG. 4B, a spring member having a desired torsional rigidity can be easily prepared.

[0037] According to one embodiment, the eight sensors 3 are offset from one another in the circumferential direction D3, and therefore can have different flaw detection ranges in the circumferential direction D3, allowing the piping 50 to be inspected widely in the circumferential direction D3.

[0038] According to one embodiment, it is possible to provide a pipe inspection probe 1 having eight sensors 3 (8 channels) and improved insertability into a pipe 50. This pipe inspection probe 1 can be inserted into a pipe 50 having an inner diameter of 20 mm or more and 105 mm or less. Furthermore, this pipe inspection probe 1 can pass through a curved portion of the pipe 50 having a curvature radius of 35 mm or less. Note that the pipe inspection probe 1 is not limited to 8 channels, and may have any number of channels.

[0039] A piping inspection probe 1 according to another embodiment will be described. In another embodiment, the same components as those in the above-described embodiment are given the same reference numerals, and detailed description thereof will be omitted. FIG. 5 is a diagram showing a schematic configuration of a piping inspection probe 1 according to another embodiment. In another embodiment, the piping inspection probe 1 has 16 sensors 3 (16 channels). The first sensor holder 2 supports four first sensors 23 out of the 16 sensors. The second sensor holder 4 supports four second sensors 43 out of the 16 sensors. The third sensor holder 6 supports four third sensors 63 out of the 16 sensors. The fourth sensor holder 8 supports four fourth sensors 83 out of the 16 sensors. The four first sensors 23, the four second sensors 43, the four third sensors 63, and the four fourth sensors 83 are each arranged in one sensor row at intervals in the circumferential direction D3.

[0040] In another embodiment, the four first sensors 23 are arranged such that the angular positions θ are shifted by 90 degrees. The four second sensors 43 are arranged such that the angular positions θ are shifted by 90 degrees. The four third sensors 63 are arranged such that the angular positions θ are shifted by 90 degrees. The four fourth sensors 83 are arranged such that the angular positions θ are shifted by 90 degrees. The four first sensors 23, the four second sensors 43, the four third sensors 63, and the four fourth sensors 83 (i.e., the 16 sensors 3) are shifted from one another in the circumferential direction D3.

[0041] The contents described in each of the above embodiments can be understood, for example, as follows.

[0042] [1] The piping inspection probe (1) according to the present disclosure is A pipe inspection probe for inspecting a pipe from inside the pipe, comprising: a first sensor holder (2) in which a plurality of first sensors (23) capable of transmitting and receiving ultrasonic waves are arranged in a sensor row at intervals in a circumferential direction (D3); a second sensor holder (4) in which a plurality of second sensors (43) capable of transmitting and receiving ultrasonic waves are arranged in a sensor row at intervals in the circumferential direction; The pipe inspection probe further includes a flexible member (10) having a predetermined torsional rigidity, which connects the first sensor holder and the second sensor holder so as to be aligned in an axial direction (D1) of the pipe inspection probe.

[0043] According to the configuration described in [1] above, the multiple first sensors are distributed to the first sensor holder, and the multiple second sensors are distributed to the second sensor holder. Therefore, the dimensions of the first sensor holder and the second sensor holder can be made smaller than the dimensions of one sensor holder in which the multiple first sensors and the multiple second sensors are arranged together. Furthermore, the first sensor holder has multiple first sensors arranged in one sensor row, so that the axial dimension of the pipe inspection probe is shortened. Similarly, the second sensor holder has multiple second sensors arranged in one sensor row, so that the axial dimension of the pipe inspection probe is shortened. Therefore, the first sensor holder and the second sensor holder can pass through even a pipe having a curved portion with a small bending radius, and the insertability of the pipe inspection probe into the inside of a pipe with a small diameter and a small bending radius can be improved.

[0044] [2] In some embodiments, in the configuration described in [1] above, The flexible member is a spring member, and has a cross-sectional shape that is elongated along one direction.

[0045] The resistance to twisting (torsional rigidity) of the spring member is affected by the second moment of area. Therefore, a spring member having a rectangular cross-sectional shape is more difficult to twist than a spring member having a square cross-sectional shape. Similarly, a spring member having an elliptical cross-sectional shape is more difficult to twist than a spring member having a circular cross-sectional shape. According to the configuration described in [2] above, by making the spring member less susceptible to twisting, the positions of the multiple first sensors are prevented from shifting in the circumferential direction, and the positions of the multiple second sensors are prevented from shifting in the circumferential direction. In other words, the occurrence of missing or leaking in the flaw detection ranges of the multiple first sensors and the multiple second sensors is prevented. Therefore, the pipe inspection probe can inspect the pipe widely in the circumferential direction of the pipe inspection probe from inside the pipe.

[0046] [3] In some embodiments, in the configuration described in [2] above, The spring member is a rectangular wire spring, and has a cross-sectional shape that is elongated along the radial direction of the piping inspection probe and has a short side along the axial direction of the piping inspection probe.

[0047] In order for the pipe inspection probe to pass through the curved portion of the pipe, it is desirable that the spring member has a certain degree of flexibility. In addition, in order to prevent the spring member from twisting and the first sensor holder and the second sensor holder from rotating relative to each other when the pipe inspection probe is inserted, and to prevent the first sensors and the second sensors from coming off or leaking in the circumferential detection range, it is desirable that the spring member has a certain degree of resistance to twisting (torsional rigidity). According to the knowledge of the present inventors, by using a square wire spring as the spring member, the spring member can have a certain degree of flexibility and resistance to twisting. Therefore, according to the configuration described in [3] above, it is possible to provide a pipe inspection probe that is easy to insert into the inside of the pipe and can widely inspect the pipe in the circumferential direction of the pipe inspection probe.

[0048] [4] In some embodiments, in the configuration according to any one of [1] to [3] above, If the length of the first sensor holder in the radial direction of the pipe inspection probe is L1 and the length of the first sensor holder in the axial direction of the pipe inspection probe is L2, then L2≦1.2L1 is satisfied.

[0049] According to the configuration described in [4] above, the axial length of the pipe inspection probe of the first sensor holder can be shortened compared to the conventional configuration, thereby improving the ease of inserting the pipe inspection probe into the inside of the pipe.

[0050] [5] In some embodiments, in the configuration according to any one of [1] to [4] above, The first sensors and the second sensors are offset from one another in a circumferential direction of the pipe inspection probe.

[0051] According to the configuration described in [5] above, the first sensors and the second sensors can each have a different detection range in the circumferential direction of the pipe inspection probe, so that the pipe can be widely inspected in the circumferential direction of the pipe inspection probe.

[0052] [6] In some embodiments, in the configuration according to any one of [1] to [5] above, the plurality of first sensors are two first sensors, the plurality of second sensors are two second sensors, a third sensor holder (6) in which two third sensors (63) capable of transmitting and receiving ultrasonic waves are arranged in a sensor row spaced apart from each other in the circumferential direction; a fourth sensor holder (8) in which two fourth sensors (83) capable of transmitting and receiving ultrasonic waves are arranged in a sensor row spaced apart from each other in the circumferential direction; The first sensor holder, the second sensor holder, the third sensor holder, and the fourth sensor holder are connected by the flexible member so as to be aligned in the axial direction of the pipe inspection probe.

[0053] According to the configuration described in [6] above, it is possible to provide a pipe inspection probe having eight sensors (eight channels) and improved insertability into the inside of a pipe.

[0054] [7] In some embodiments, in the configuration according to any one of [1] to [5] above, the plurality of first sensors are four first sensors; the plurality of second sensors is four second sensors; a third sensor holder in which four third sensors capable of transmitting and receiving ultrasonic waves are arranged in a sensor row spaced apart from one another in a circumferential direction; a fourth sensor holder in which four fourth sensors capable of transmitting and receiving ultrasonic waves are arranged in a sensor row at intervals in the circumferential direction; The first sensor holder, the second sensor holder, the third sensor holder, and the fourth sensor holder are connected by the flexible member so as to be aligned in the axial direction of the pipe inspection probe.

[0055] According to the configuration described in [7] above, it is possible to provide a pipe inspection probe having 16 sensors (16 channels) and improved insertability into the inside of a pipe. [Explanation of symbols]

[0056] 1 Pipe Inspection Probe 2 First sensor holder 3 Sensors 4 Second Sensor Holder 6 Third Sensor Holder 8 4th Sensor Holder 10 Flexible member 11a proximal end 11b Tip 12 Tip guide 13 Tip shaft 14 Alignment jig 18 Base end shaft 23 First Sensor 30 Main body 32 Brushes 43 Second Sensor 50 Piping 51 Inside 63 3rd Sensor 83 4th Sensor 102 Joiner 104 Long members 106 Transport Equipment D1 Axial direction D2 radial direction D3 Circumferential direction O axis X Virtual Line

Claims

1. A pipe inspection probe for inspecting a pipe from inside the pipe, comprising: a first sensor holder in which a plurality of first sensors capable of transmitting and receiving ultrasonic waves are arranged in a sensor row at intervals in a circumferential direction; a second sensor holder in which a plurality of second sensors capable of transmitting and receiving ultrasonic waves are arranged in a sensor row at intervals in a circumferential direction; a flexible member having a predetermined torsional rigidity that connects the first sensor holder and the second sensor holder so as to be aligned in the axial direction of the pipe inspection probe; Plumbing inspection probe.

2. The flexible member is a spring member and has a cross-sectional shape that is elongated along one direction. The pipe inspection probe of claim 1 .

3. The spring member is a square wire spring, and has a cross-sectional shape that is longitudinal along the radial direction of the pipe inspection probe and transverse along the axial direction of the pipe inspection probe. The pipe inspection probe of claim 2 .

4. When the radial length of the pipe inspection probe of the first sensor holder is L1 and the axial length of the pipe inspection probe of the first sensor holder is L2, L1≦L2≦1.2L1 is satisfied. A piping inspection probe according to any one of claims 1 to 3.

5. the first sensors and the second sensors are offset from each other in a circumferential direction of the pipe inspection probe; A piping inspection probe according to any one of claims 1 to 3.

6. the plurality of first sensors are two first sensors, the plurality of second sensors are two second sensors, a third sensor holder in which two third sensors capable of transmitting and receiving ultrasonic waves are arranged in one sensor row at intervals in the circumferential direction; a fourth sensor holder in which two fourth sensors capable of transmitting and receiving ultrasonic waves are arranged in one sensor row at intervals in the circumferential direction; the first sensor holder, the second sensor holder, the third sensor holder, and the fourth sensor holder are connected to each other by the flexible member so as to be aligned in an axial direction of the pipe inspection probe; A piping inspection probe according to any one of claims 1 to 3.

7. the plurality of first sensors are four first sensors, the plurality of second sensors is four second sensors; a third sensor holder in which four third sensors capable of transmitting and receiving ultrasonic waves are arranged in a sensor row spaced apart from one another in a circumferential direction; a fourth sensor holder in which four fourth sensors capable of transmitting and receiving ultrasonic waves are arranged in one sensor row at intervals in the circumferential direction; the first sensor holder, the second sensor holder, the third sensor holder, and the fourth sensor holder are connected to each other by the flexible member so as to be aligned in an axial direction of the pipe inspection probe; A piping inspection probe according to any one of claims 1 to 3.

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