JPH0455241B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to an in-pipe inspection device used for inspecting cable pipes, gas pipes, water pipes, sewage pipes, and the like.

(Prior Art) Various types of pipe inspection devices have been developed depending on the purpose of the inspection. Among them, when a cable is buried in a buried pipe, there is a device that inspects whether the cable can be guided in advance. This is to check for pipe diameter reduction due to bending or deformation of the pipe, adhesion of stones, concrete, etc. inside the pipe, and to check for external pressure being applied to the cable due to the reduction in pipe diameter, and to use this as a basis for making decisions regarding cable installation. .

As this type of inspection device, there is a device disclosed in Japanese Patent Publication No. 60-21321. As shown in FIG. 7, this device is equipped with a guide arm 12 that elastically protrudes in the radial direction at the rear of the outer periphery of a measuring instrument body 10, and a roller 1 attached to the tip of the guide arm 12.
3 is installed. Further, a telescopic arm 15 constituting a link mechanism 14 is projected from the front outer circumference of the measuring instrument main body 10, and a roller 16 is attached to the projecting portion. By expanding and contracting the link mechanism 14 according to the diameter of the pipe 20, the core 18 of the differential transformer 17 can be driven, and the change in electrical output is extracted as pipe diameter information.

(Problems to be Solved by the Invention) According to the conventional device, as shown in FIG. 8, for example, in the bending tube 21, the positions of the rollers 16, 16 do not match accurately in the radial direction of the tube. , there is a problem that accurate tests cannot be obtained. In addition, when measuring not only the bent tube but also the bent tube section, the roller 1
6 and 16 do not coincide with the line extended from the center of curvature, and there is a problem that accurate measurement of the pipe diameter cannot be obtained.

Furthermore, FIG. 7B shows the above-mentioned inspection device from the tube axis direction, and since the arm is configured to protrude in a direction radiating from the main body, there may be foreign objects (concrete, stones, etc.) between the rollers 16 as shown. If 22 is present, it cannot be detected and may become a hindrance when inserting the cable later.

Therefore, when a cable is actually laid inside a pipe, the external pressure applied to the cable may contradict the measurement results.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a pipe inspection device having a structure capable of eliminating pipe measurement errors and obtaining accurate judgment information.

[Structure of the Invention] (Means for Solving the Problems) The present invention includes a slider portion that surrounds a central axis and is slidable in the axial direction, a first arm tip is attached to the slider portion, and a second arm tip is attached to the slider portion. a plurality of unit links rotatably attached to the shaft, and connecting portions of the first and second arms protrude radially from the shaft; a portion of the inner wall is respectively connected to the connecting portion; It is composed of a plurality of plates that surround a plurality of unit link parts in the direction around the central axis to form a cylindrical shape, and the axially regular part of each plate is composed of an envelope having an overlapping structure.

(Function) With the above means, when external pressure is applied to the envelope, the diameter of the envelope is reduced in the central axis direction by the action of the link mechanism, and when the external pressure is removed, the diameter of the envelope is reduced. It operates to restore the diameter. This device has a cylindrical outer diameter, and can accurately detect the minimum diameter when inspecting bent tubes, bending tubes, etc., and can also detect foreign objects such as concrete or stones inside the tube. This allows the minimum diameter of this portion to be reliably detected without being overlooked.

(Example) Examples of the present invention will be described below with reference to the drawings.

FIG. 1 shows an embodiment of the present invention, in which A is a sectional view, and B and C are views showing an example of the external shape. 30 is a central axis of the inspection device, and a slider 31 is attached to this central axis 30, and this slider 31 is slidable in the axial direction. The tip of one arm 35 constituting the link mechanism 34 is rotatably attached to the slider 31. Further, the tip of the other arm 36 constituting the link mechanism 34A is rotatably attached to a part of the central shaft 30. The connecting portions of the arms 35 and 36 are arranged in a direction radiating from the central axis 30, and this portion is connected to a part of the inner wall of the plate 401. The distal ends and connecting portions of the arms 35 and 36 are rotatably supported by shafts and constitute a unit link mechanism. A plurality of such unit link mechanisms are further provided as shown by 34B, 34C, and 34D, radiate around the central axis 30, and support a plurality of plates.

The unit link mechanism parts 34B and 34D are plate 4
02, unit link mechanism part 34A,
34C supports the plate 401. Although only four unit link mechanisms are shown in the figure, they are also provided at other angular positions and support other plates.

Here, the slider 31 is biased by the spring 36 in the direction opposite to the arrow B shown in the figure, and the arm 3
The tips of Nos. 5 and 36 are brought closer together. That is, the link mechanism acts elastically in a direction that moves the plates 401, 402 away from the central axis 30.

The envelope 407 formed by the plates 401, 402, 403 to 406 has a substantially cylindrical shape, as shown in FIG. 4B or C, for example.

Further, the plate 4 constituting the envelope 407
As shown in FIG. 2, 01 to 406 are arranged such that their axial side portions overlap each other with a step, so that the diameter of the envelope 407 can be expanded and contracted smoothly. The stepped portion serves as a stopper when the envelope 407 is contracted to its smallest diameter, and protects the inside.

Furthermore, FIGS. 3A and 3B show a part of the envelope of FIG. It has been accomplished. That is, when a foreign object passes in the direction of arrow X, the protrusion 06A
collides with a foreign object. As a result, the diameter of the envelope is reduced, but the protrusion 06A is
Since it enters A, there is no problem in reducing the diameter. Although only one location is shown in the figure, as can be seen from FIG. 1C, detection supplementary sections 01A to 04A as shown in FIG. 3 are provided at multiple locations between the plates.

FIG. 4 shows the unit link mechanism section 34C of FIG.
34D is shown in more detail, showing a structure for transmitting the movement of the slider 35 to the core 51 of the differential transformer 50.

The slider 35 is movable in the illustrated arrow YZ direction by the action of the link mechanisms 34C and 34D. The slider 35 is connected via a pin 61 to a drive piston 62 housed in the center shaft 30 . Therefore, the slider 35 is indicated by the arrow Y in the diagram.
If it moves in the -Z direction, the drive piston 62 also moves in the illustrated arrow YZ direction. This drive piston 62 has a core 51 of the differential transformer 50.
The tip is attached by screw means. Further, a rose-like waterproofing device 63 is attached between the guide portion of the core 51 of the differential transformer 50 and the end of the drive piston 62 to make the core 51 waterproof.

FIG. 5 is an explanatory diagram showing the state in which the apparatus of the present invention is used.

Figure A shows a pipe diameter measurement method when a differential transformer is not installed inside the central shaft. The device 80 is inserted into the underground pipe 70 and pulled by the winch 73 via a wire. At this time winch 7
3 is provided with a torque limiter 72,
The output is recorded, for example, by a recording device. In other words, as the diameter of the tube changes and a traction load is applied to the device 80, the diameter of the tube becomes smaller. Therefore, the recording device can record changes in the diameter of the tube according to the amount of winding of the wire.

FIG. 5B shows a pipe interior inspection method when the apparatus 80 of the present invention is equipped with a differential transformer inside as shown in FIG. 4. Device of the present invention 80
is pulled by a winch 73 and advances inside the underground pipe 70, and the pipe diameter measurement information is supplied to a recording device 75 electrically connected to the differential transformer. Note that various embodiments are possible as the recording device. By recording the output of the differential transformer or the output of the torque limiter with a pen recorder or the like according to the amount of cable feeding or winding, the position and amount of deformation of the tube can be measured. The amount of cable feeding or winding can be measured by measuring the rotation detection pulse of the winch or guide roller.

FIG. 6 shows a simplified version of the device 80 of the present invention. In the case of the device 80 of the present invention, the envelope is configured in a cylindrical shape and has a structure that is freely expandable and contractable in the radial direction. Therefore, even if the pipe line of the pipe 70 is bent, when passing through this part, the pipe inner diameter dimension and the pressure from the pipe inner wall can be measured in the same state as when the cable is actually passed through. Therefore, if the measurement is performed in advance using the apparatus of the present invention before laying the cable, it can be used as a basis for determining appropriate cable installation and pipe repair.

[Effects of the Invention] As described above, the present invention can provide a pipe inspection device having a structure that eliminates pipe measurement errors and can obtain accurate judgment information.

[Brief explanation of the drawing]

Fig. 1 is a cross-sectional view and an external perspective view showing an embodiment of the present invention, Fig. 2 is an explanatory diagram of the operation of the inventive device, Fig. 3 is a diagram showing a part of the inventive device, and Fig. 4 is a diagram illustrating the operation of the inventive device. A sectional view showing another embodiment of the invention, FIG. 5 is an explanatory view showing how the inventive device is used, and FIG. 6 is an explanatory view showing an example of the operation of the inventive device.
Figure 7 is an explanatory diagram of the configuration of a conventional pipe inspection device;
The figure is an explanatory diagram of the operation of a conventional pipe inspection device. 30... Central axis, 31, 35... Slider, 3
4A to 34D...Unit link mechanism section, 35, 36
...Arm, 36...Spring, 401-40
6...Plate, 407...Envelope, 01A,0
2A, 03A, 04A...detection supplementary section, 50...
Differential transformer, 51...core, 62...drive piston.

Claims (1)

[Claims] 1. A slider part that surrounds a central axis and can freely slide in the axial direction; a first arm tip is attached to the slider part; a second arm tip is rotatably attached to the axis; 1. A plurality of unit link mechanisms in which the connecting portions of the second arms protrude in the radial direction from the shaft;
The connecting parts are each attached to a part of the inner wall,
An in-pipe inspection device comprising: an envelope made of a plurality of plates forming a cylindrical shape surrounding the plurality of unit link parts in a direction around the central axis. 2. The pipe inspection device according to claim 1, wherein the plurality of plates have a structure in which the axial side portions of adjacent plates overlap each other with a step. 3. The plurality of plates are characterized in that the axial side portions of adjacent plates face each other with uneven portions, and the uneven portions fit together when the diameter of the envelope is reduced. An in-pipe inspection device according to claim 1. 4. Among the unit link mechanisms, certain ones are:
The pipe inspection device according to claim 1, characterized in that a slider mounted around the central axis is driven in the axial direction of the central axis. 5. The central shaft has a hollow space, and a differential transformer is disposed therein, and a core of the differential transformer is connected to the slider via a drive piston. The pipe inspection device according to item 4. 6. Between the core guide portion of the differential transformer and the drive piston, a waterproofing device in the form of a knot or a piece is provided to prevent the core from being exposed and to prevent water from being launched from the outside. An in-pipe inspection device according to claim 5, characterized in that: