GUIDE TUBE FOR GUIDING CABLE OF INTERNAL OBSERVATION DEVICE AND CABLE GUIDING METHOD

Abstract

A guide tube guides a cable of an internal observation device into a pipe bore. The cable is pushed into the pipe bore to force an observation image capturing part provided proximate a tip end of the cable to approach a portion to be observed when performing internal observation of the pipe bore of a pipe-like structure with the internal observation device. The guide tube includes: an outside wall having an outside diameter of the guide tube that is substantially equal to an internal diameter of the pipe bore; and an internal wall having an internal diameter of the guide tube that is substantially equal to an outside diameter of the cable

Claims

1. A guide tube that guides a cable of an internal observation device into a pipe bore, wherein the cable is pushed into the pipe bore to force an observation image capturing part provided proximate a tip end of the cable to approach a portion to be observed when performing internal observation of the pipe bore of a pipe-like structure with the internal observation device, the guide tube comprising: an outside wall having an outside diameter of the guide tube that is substantially equal to an internal diameter of the pipe bore; and an internal wall having an internal diameter of the guide tube that is substantially equal to an outside diameter of the cable.

2. The guide tube that guides a cable of an internal observation device according to claim 1, further comprising: a curved part that is proximate a tip end of the guide tube and that deflects a direction in which the tip end of the cable that is inserted in a tube interior of the guide tube is directed.

3. The guide tube that guides a cable of an internal observation device according to claim 2, wherein an internal diameter proximate the curved part of the guide tube is greater than internal diameters of other parts of the guide tube.

4. The guide tube that guides a cable of an internal observation device according to claim 3, wherein the internal diameter of the guide tube continuously changes from the internal diameter of the other parts to the internal diameter proximate the curved part.

5. The guide tube that guides a cable of an internal observation device according to claim 2, wherein a tube axis of the tube interior is decentered toward a direction opposite the direction in which the tip end of the cable is deflected at a portion besides the portion proximate the tip end of the guide tube.

6. A guide tube that guides a cable of an internal observation device into a pipe bore, the guide tube comprising: an outside tube and an inside tube that is inserted in the outside tube, wherein the outside tube has an outside diameter substantially equal to an internal diameter of the pipe bore and an internal diameter substantially equal to an outside diameter of the inside tube, the inside tube has an internal diameter substantially equal to an outside diameter of the cable, and the inside tube comprises, at a tip end thereof, a holding structure for holding a part proximate a tip end of the cable that is inserted in a tube interior thereof.

7. A cable guiding method of an internal observation device, comprising: inserting into a pipe bore the cable of the internal observation device, wherein the cable is pushed into the pipe bore to force an observation image capturing part provided proximate a tip end of the cable to approach a portion to be observed when performing internal observation of the pipe bore of a pipe-like structure with the internal observation device; inserting into the pipe bore a guide tube having an outside diameter that is substantially equal to an internal diameter of the pipe bore and an internal diameter that is substantially equal to an outside diameter of the cable; and inserting the cable into a tube interior of the guide tube from an outside of the pipe bore.

8. The cable guiding method according to claim 7, wherein the guide tube includes a curved part that is proximate a tip end of the guide tube and that deflect a direction in which the tip end of the cable that is inserted in the tube interior of the guide tube is directed.

9. The cable guiding method according to claim 8, wherein a tube axis of the tube interior is decentered toward a direction opposite a direction in which the cable is deflected at a portion besides a portion proximate the tip end of the guide tube.

10. The cable guiding method according to claim 7, wherein the guide tube includes an outside tube and an inside tube inserted in the outside tube, the outside tube has an outside diameter substantially equal to the internal diameter of the pipe bore and an internal diameter substantially equal to an outside diameter of the inside tube, the inside tube has an internal diameter substantially equal to the outside diameter of the cable, the inside tube comprises, at a tip end thereof, a holding structure for holding a part proximate the tip end of the cable that is inserted in a tube interior thereof, and the method further comprises: inserting the cable into the inside tube and holding with the holding structure the part proximate the tip end of the cable; and inserting into the outside tube the inside tube having the cable fixed thereto.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0020] FIG. 1 is a diagram illustrating a schematic configuration of the internal observation device 1.

[0021] FIG. 2 is a sectional diagram of a guide tube 10 shown as the first example.

[0022] FIG. 3 is a diagram illustrating the guide tube 10 in a state inserted in the pipe 41.

[0023] FIG. 4 is a diagram illustrating the way in which the cable 2 is pushed into the tube interior 11 of the guide tube 10.

[0024] FIG. 5 is a diagram illustrating the tip end of the cable 2 in a state approaching the portion to be observed 70.

[0025] FIG. 6 is a diagram illustrating the way in which the tip end of the cable 2 abuts against the wall face of the pipe 41 at the tee structure section.

[0026] FIG. 7 is a sectional diagram of a guide tube 10 shown as the second example.

[0027] FIG. 9 is a diagram explaining the way in which the guide tube 10 shown as the second example works.

[0028] FIG. 9 is a diagram illustrating the method of setting the internal diameter of the guide tube 10.

[0029] FIG. 10 is a diagram illustrating an example of the guide tube 10 having the tube axis of the tube interior 11 decentered.

[0030] FIG. 11 is a sectional diagram of a guide tube 10 shown as the third example.

[0031] FIG. 12 is a diagram illustrating the cable 2 in a state inserted in the inside tube 10B.

[0032] FIG. 13 is a diagram illustrating the outside tube 10A in a state inserted in the pipe bore of the pipe 41.

[0033] FIG. 14 is a diagram illustrating the inside tube 10B in a state inserted in the outside tube 10A.

[0034] FIG. 15 is a diagram illustrating the cable 2 bending inside the pipe bore.

DESCRIPTION OF EMBODIMENTS

[0035] The following describes in detail embodiments of the invention with reference to the drawings. In the following description, the same or similar parts are attached similar reference numbers and duplicate explanation thereof may be omitted.

First Example

[0036] FIG. 1 illustrates a schematic configuration of the internal observation device 1 (videoscope, fiberscope and the like) which are used for internal observation of a pipe-like structure 40 (including pipes 41A, 41B) using the guide tube 10 shown as the first example.

[0037] As illustrated in FIG. 1, the internal observation device 1 according to one or more embodiments includes a cable 2 provided with an observation image capturing part 21 proximate one end thereof (hereinafter also called tip end) and a main device 3 to which the other end (hereinafter also called rear end) of the cable 2 is connected.

[0038] The main device 3 includes a central processing device (CPU, MPU and the like), a memory (ROM, RAM and the like), a display device 5 (liquid crystal panel, organic EL panel and the like) and an input device 6 (keypad, touch panel and the like.) And an image based on the observation image or an image signal supplied from the observation image capturing part 21 and transmitted through the cable 2 is reproduced and output.

[0039] When the internal observation device 1 is, for example, a videoscope, the observation image capturing part 21 includes, for example, a solid-state image sensing device (charge-coupled device (CCD), complementary metal oxide semiconductor (CMOS) and the like), and the cable 2 is, for example, a jacket coated metal cable that transmits to the main device 3 electrical signals of the observation image that are photoelectrically converted using the solid-state image sensing device. Further, when the internal observation device 1 is, for example, a fiberscope, the observation image capturing part 21 includes an optical element such as, for example, an eyepiece and the like and the cable 2 is, for example, a jacket coated optical fiber cable that transmits to the main device 3 as optical signals the observation image that has optical elements input.

[0040] During internal observation, the user inserts the cable 2 of the internal observation device 1 by hauling the cable 2 so that the cable 2 is pushed in from the opening of the pipe 41 that is communicated to the portion to be observed 70, in order to bring the observation image capturing part 21 of the cable 2 closer to the portion to be observed 70 in the pipe 41. Here, the guide tube 10 functions such that the cable 2 is prevented from bending in the pipe bore of the pipe 41 as well as that the pushing force applied to the cable 2 effectively acts on the cable 2 as the advancement force toward the portion to be observed 70.

[0041] FIG. 2 is a sectional diagram (sectional diagram showing the guide tube 10 cut along a face in the lengthwise direction thereof so to include the tube axis) illustrating a guide tube 10 shown as the first example. The guide tube 10 is in a cylindrical form. The material of the guide tube 10 is such as resin, however, the material of the guide tube 10 may be selected to have a sufficiently high rigidity compared to the cable 2. Further, the lengthwise length of the guide tube 10 may be at least the same or longer than the sum length obtained by adding the length from the opening of the pipe 41 being the insert hole for the cable 2 to the section required for allowing the observation image capturing part 21 of the cable 2 to smoothly approach the portion to be observed 70 and the length of the section that serves as the handle when inserting the cable 2 into the tube interior 11 of the guide tube 10.

[0042] The outside diameter of the guide tube 10 is substantially equal to the internal diameter of the pipe bore of the pipe 41 to a degree that the guide tube 10 can be inserted in the pipe bore of the pipe 41 through which the cable 2 is inserted, and the internal diameter of the tube interior 11 of the guide tube 10 is substantially equal to the outside diameter of the cable 2 to a degree that the cable 2 can be inserted therein. Here, the reason for setting the outside diameter of the guide tube 10 to be substantially equal to the internal diameter of the pipe bore of the pipe 41 to a degree that the pipe bore, of the pipe 41 through which the cable 2 is to be inserted, can have inserted the guide tube 10 is to prevent the guide tube 10 itself from bending when the cable 2 is inserted into the pipe bore. Further, the reason for the internal diameter of the tube interior 11 of the guide tube 10 being substantially equal to the outside diameter of the cable 2 is to prevent the cable 2 from bending when inserting the cable 2 into the guide tube 10.

[0043] Here, the diameter of the tube interior 11 of the guide tube 10 may have a dimension such that some space is secured between the outside diameter of the cable 2 so that the cable 2 can be smoothly inserted into the tube interior 11. Additionally, the material of the surface of the tube interior 11 of the guide tube 10 and the material of the surface of the cable 2 may be selected such that the friction coefficient between the two becomes small.

[0044] A user uses the guide tube 10 in the following manner during an internal observation of the pipe-like structure 40. To be specific, the user firstly inserts the guide tube 10 into the pipe 41 before inserting the cable 2 into the pipe 41. FIG. 3 illustrates the guide tube 10 in a state inserted in the pipe 41. The cable 2 may be inserted in the pipe 41 together with the guide tube 10 or in this case, the cable 2 may be inserted in the guide tube 10 before inserting the guide tube 10 into the pipe 41.

[0045] Subsequently, the user pushes the cable 2 into the tube interior 11 of the guide tube 10 so to force the tip end of the cable 2 to approach the portion to be observed 70. FIG. 4 illustrates the way in which the cable 2 is pushed into the tube interior 11 of the guide tube 10 and FIG. 5 illustrates the tip end of the cable 2 in a state approaching the portion to be observed 70. The user performs an operation of focusing and the like with the main device 3 in the state shown in FIG. 5 and displays on the display device of the main device 3 the image taken from the observation image capturing part 21.

[0046] In this way, the use of the guide tube 10 prevents a situation where the cable 2 is bent to allow the pushing force to be dispersed when inserting the cable 2 into the pipe bore 21 thereby making it difficult for the cable 2 to be pushed in. Further, the use of the guide tube 10 allows the pushing force to effectively act on the cable 2 as the advancement force of the cable 2 so to thereby force the tip end of the cable 2 to smoothly approach the portion to be observed 70. Hereby, the burden on the user during internal observation of the pipe-like structure 40 can be greatly reduced. Additionally, the observation image capturing part 21 of the cable 2 can be easily sent deep inside the pipe 41 of the pipe-like structure 40 so that the condition of the pipe-like structure 40 can be certainly and promptly confirmed. Further, indications of such as the blockage of the pipe bore can be detected in advance so that appropriate measures can be taken promptly.

Second Example

[0047] For example, when the portion to be observed 71 exists at a place further beyond the tee structure section 411 of the pipe 41, as illustrated in FIG. 6, the cable 2 would not be able to be further pushed in since the observation image capturing part 21 abuts against the wall face of the pipe 41 at the tee structure section 411 making it difficult for the observation image capturing part 21 of the cable 2 to approach the portion to be observed 71.

[0048] FIG. 7 is a sectional diagram (a sectional diagram showing the guide tube 10 cut along a face in the lengthwise direction thereof so to include the tube axis) illustrating a guide tube 10 shown as the second example configured to avoid the circumstances given above. As illustrated in FIG. 7, a curved part 12 that deflects the direction in which the cable 2 advances is provided proximate the tip end of the guide tube 10.

[0049] The advancement direction of the cable 2 is deflected to the direction toward the portion to be observed 71 at the curved part 12 when using this guide tube 10 as illustrated in FIG. 8. Therefore, the tip end of the cable 2 can be made to smoothly approach the portion to be observed 71 by an operation of pushing in the cable 2 from outside the tube.

[0050] The cable 2 usually includes at the tip end thereof a stiff portion (a cylindrical metal case surrounding the circumference of the observation image capturing part 21 in the present example which is hereinafter called stiff portion 22) that lacks flexibility and that has a predetermine length (e.g., about 10 to 15 mm) for protecting the observation image capturing part 21 and the like. This stiff portion 22 may get stuck at the curved part 12 preventing the cable 2 from advancing. For such reason, it is recommended that the inside tube diameter at the curved part 12, for example, can be widened to allow the stiff portion 22 to smoothly pass through the curved part 12 when the cable includes such stiff portion 22.

[0051] In this case, the inside tube diameter of the guide tube 10 at the curved part 12 can be appropriately set using, for example, the following relation. Specifically, with reference to FIG. 9, when the wall thickness of the guide tube 10 is set to t, the internal diameter of the pipe 41A is set to a, the outside diameter of the guide tube 10 is set to b (so the internal diameter of the guide tube 10 is b2t), the angle formed by the central axis of the stiff portion 22 (central axis of the observation image capturing part 21) and the central axis of the pipe 41A is set to , the length of the stiff portion 22 (not deformable) is set to L, the margin length required for bending the cable 2 at the rear of the stiff portion 22 positioned at the tip end of the cable is set to , and the diameter of the stiff portion 22 is set to d, the following equation needs to be satisfied between the above variables for allowing the stiff portion 22 to pass through.

L+<((ad*cos t)/sin +(bd)/sin t)/cos ))min

[0052] Therefore, the inner tube diameter b of the guide tube 10 at the curved part 12 should satisfy the above equation.

[0053] And when the stiff portion 22 is included at a mid-part of the cable, the inner tube diameter b of the guide tube 10 at the curved part 12 should satisfy the following equation.

L+2<((ad*cos t)/sin +(bd)/sin t)/cos ))min

[0054] By the way, the internal diameter of the guide tube 10 may be made to continuously change from the internal diameter of other parts (besides those proximate the curved part 12) to the internal diameter proximate the curved part 12 so that the cable 2 can be smoothly passed through the curved part 12.

[0055] Further, for example, the tube axis of the tube interior of the guide tube 10 may be decentered toward the direction opposite the direction in which the cable 2 is deflected by the action of the curved part 12, at a portion besides that proximate the curved part 12 (proximate the tip end), as illustrated in FIG. 10. In this way, the radius of curvature of the cable 2 that bends at the curved part 12 can be maximized so to reduce the friction between the cable 2 and the wall face of the pipe bore of the pipe 41 to thereby allow the cable 2 to be further smoothly inserted into the pipe bore.

Third Example

[0056] FIG. 11 is a sectional diagram (a sectional diagram showing the guide tube 10 cut along a face in the lengthwise direction thereof so to include the tube axis) illustrating a guide tube 10 shown as the third example. As illustrated in FIG. 11, the guide tube 10 of the third example is a double-layered tube structure including an outside tube 10A and an inside tube 10B that is inserted into the outside tube 10A. The outside diameter of the outside tube 10A is substantially equal to the internal diameter of the pipe 41 to a degree that the guide tube 10 can be inserted in the pipe bore of the pipe 41 through which the cable 2 is inserted, and the internal diameter of the outside tube 10A is substantially equal to the outside diameter of the inside tube 10B to a degree that the inside tube 10B can be inserted therein. Further, the inside tube 10B has the internal diameter thereof set to be substantially equal to the outside diameter of the cable 2 to a degree that the cable 2 can be inserted therein. Additionally, the tip end of the inside tube 10B has provided thereto a holding structure 15 (elastic tube, clip and the like) for holding the part proximate the tip end of the cable 2 that is inserted in the inside tube 10B.

[0057] The cable 2 inserted into the pipe 41 using the guide tube 10 of the third example is performed in, for example, the following manner. To be specific, the user firstly inserts the cable 2 into the inside tube 10B and then fixes the tip end of the cable 2 (periphery of the observation image capturing part 21) using the holding structure 15, as shown in FIG. 12. Subsequently, the user inserts the outside tube 10A into the pipe bore of the pipe 41, as shown in FIG. 13. Thereafter, the user inserts the inside tube 10B into the tube interior of the outside tube 10A with the cable 2 in a fixed state, as shown in FIG. 14.

[0058] Since the tip end of the cable 2 is fixed to the tip end of the inside tube 10B with the holding structure 15 in the above case, the pushing force applied when pushing the inside tube 10B into the tube interior of the outside tube 10A is effectively transmitted to a part proximate the tip end of the cable 2. Hereby, the cable 2 can be made to easily approach the portion to be observed 70 without the cable 2 bending.

[0059] Although the disclosure has been described with respect to only a limited number of embodiments, those skilled in the art, having benefit of this disclosure, will appreciate that various other embodiments may be devised without departing from the scope of the present invention. Accordingly, the scope of the invention should be limited only by the attached claims.

REFERENCE SIGNS LIST

[0060] 1 internal observation device, 2 cable, 3 main device, 5 display device, 6 input device, 10 guide tube, 11 tube interior, 12 curved part, 15 holding structure, 21 observation image capturing part, 22 stiff portion, 40 pipe-like structure, 41 pipe, 41A, 41B pipe, 70, 71 portion to be observed