JP3818797B2 - In-pipe inspection device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an in-pipe inspection apparatus, and more particularly, to an in-pipe inspection apparatus in which a cable in an inspection apparatus provided with a TV camera is inserted from the outside of a pipe into a pipe filled with pressurized water.
[0002]
[Prior art]
As a method of inspecting the internal state of the pipe through which pressurized water flows, a cable with a propellant with a built-in TV camera attached to the tip is inserted into the pipe from the fire hydrant, and the TV camera Endoscopic endoscopic methods for inspecting and inspecting are known. The cable insertion device in this in-tube endoscopic method is generally one in which a cable is inserted into the case from outside the case communicating with the inside of the tube, and this cable is fed into the tube by an appropriate feeding device.
[0003]
In such a cable insertion device, since the cable from the outside of the case passes through the wall portion of the case communicating with the inside of the pressurized tube, the periphery of the cable must be sealed in this through portion. For this reason, conventionally, a required seal is performed by compressing an O-ring fitted to the cable.
[0004]
[Problems to be solved by the invention]
However, since it is necessary to feed the cable, that is, move the cable in the axial direction after passing the cable through the inner periphery of the O-ring compressed in this way, there is a problem that the cable is likely to be greatly deformed. There is a point.
SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to solve such problems and to insert the cable into a pipe without causing a large deformation in the cable used in the pipe endoscopic method.
[0005]
[Means for Solving the Problems]
In order to achieve this object, the present invention is an in-pipe inspection apparatus provided with a cable insertion device provided upward from a pipe for inserting a cable from the outside of the pipe into a pipe filled with pressurized water. The cable insertion device is provided with a case that communicates with the inside of the pipe and through which the cable is passed. A through-hole through which a cable from the outside of the pipe is passed is formed in a wall portion of the case. A gap is formed between the cable passed through the pipe, and pressurized air is supplied to a portion communicating with the gap below the through hole in the case to increase the pressure of water rising from the inside of the pipe into the case. Means for positioning the water surface is provided where the pressure of the pressurized air is balanced .
[0006]
With such a configuration, the pressurized air is supplied to the portion communicating with the gap below the through hole in the case, and the pressure of the water rising from the inside of the pipe into the case and the pressure of the pressurized air Since the water surface is positioned where the two are balanced, the pressurized air supplied into the case enters the gap, and the pressurized water in the pipe does not reach, so there is no gap between the cable and the case. It will be sealed. Since a gap is formed between the cable and the through-hole through which the cable passes, the cable is hardly subjected to substantial deformation when passing through the case.
[0007]
DETAILED DESCRIPTION OF THE INVENTION
In FIG. 1, reference numeral 11 denotes a pipe for underground water buried in the ground, and this pipe is provided with a pit for an underground fire hydrant at an appropriate distance. In this pit, a branch pipe from the pipe 11 is provided. 12 is provided upward. A fire hydrant (not shown) is attached to the upper end of the branch pipe 12 via a sub valve 13. When carrying out the endoscopic method, the auxiliary valve 13 is closed, the fire hydrant is removed, and a vertical cable insertion device 14 is connected to the upper end of the auxiliary valve 13 as shown in the figure.
[0008]
The cable insertion device 14 is connected to the flange pipe 15 connected to the sub valve 13 instead of the fire hydrant, the cable feed roller device 16 connected to the upper end of the flange pipe 15, and the upper end of the cable feed roller device 16. And a water stop case 18 connected to the upper end of the chamber 17.
A flange 19 at the upper end of the cable feed roller device 16 is disposed on or near the ground surface, and a vertical guide rod 20 that slidably penetrates the flange 19 in a sealed state is provided between the cable feed roller device 16 and the flange tube. 15, the auxiliary valve 13 and the branch pipe 12 are provided so as to reach the inside of the pipe line 11. A halved guide tube 21 is provided at the lower end of the guide rod 20, and a propulsion body 22 equipped with a TV camera as a tube endoscopic device is temporarily fixed to the guide tube 21 by a holder 23. Contained in state. A cable 25 is connected to the propulsion body 22. The cable 25 includes a plurality of electric wires 26 such as a power supply line, a video signal line, and a control signal line.
[0009]
The cable 25 passes from the propulsion body 22 through the branch pipe 12, the sub-valve 13, the flange pipe 15, the cable feed roller device 16, the chamber 17, and the water stop case 18, and is provided at the upper end of the water stop case 18. It penetrates the water-stop part 27 formed and is led out of the cable insertion device 14. The cable feeding roller device 16 is provided with a roller 28, which is composed of a pair of rollers 28, 28 of the illustrated roller 28 and another roller 28 (not shown) provided in front of the paper surface of FIG. The cable 25 is sandwiched. Reference numeral 29 denotes a handle, which can feed the cable 25 in the axial direction by rotating the illustrated roller 28.
[0010]
The water stop portion 27 at the upper end of the water stop case 18 is configured as shown in detail in FIG. That is, a through hole 31 is formed at the upper end of the water stop case 18, and the cable 25 is passed through the through hole 31. A natural leather packing 32 is provided in the through hole 31 on the outer side of the water-stopping case 18, and the packing 32 is configured to be pressed by a cap 33 screwed into the upper end of the water-stopping case 18. The cable 25 also penetrates the packing 32 and the cap 33, and its periphery is lightly sealed by the packing 32. A gap 35 through which air 34 of a predetermined pressure can pass is formed between the inner periphery of the through hole 31, the packing 32 and the cap 33 and the outer periphery of the cable 25.
[0011]
FIG. 2 shows the chamber 17 and the water stop case 18 integrally for the sake of simplicity. As shown in FIGS. 1 and 2, the water stop case 18 is supplied with pressurized air 34 from the compressor 37. It is supplied via the regulator 38.
The cable insertion device 14 communicates with the inside of the pipe line 11 via the branch pipe 12, and thus the pressurized water 39 from the pipe line 11 rises in the inside, as described above. Since the pressurized air 34 is supplied to the water stop case 18, the water surface 40 is positioned where the pressure of the air 34 and the pressure of the rising water 39 are balanced. Specifically, the air pressure 41 of the air 34 and the water pressure 42 of the water 39 are sent from the chamber 17 to the control unit 43, and the control unit 43 is arranged so that the water surface 40 is located at a predetermined level in the chamber 17. The regulator 38 is controlled to adjust the pressure of the pressurized air 34. As shown in FIG. 1, the chamber 17 is provided with a gauge 44 for observing the level of the water surface 40 from the outside.
[0012]
In such a configuration, when the inside of the pipe is viewed, the auxiliary valve 13 is closed, the fire hydrant attached to the auxiliary valve 13 is removed, and instead the holder 23 temporarily supports the guide cylinder 21. The cable insertion device 14 in a state where the stopped propulsion body 22 is accommodated in the flange pipe 15 is attached to the sub valve 13. In this state, the auxiliary valve 13 is opened, and the portion of the guide rod 20 protruding from the flange 19 of the cable feed roller device 16 is pushed down. Then, the propulsion body 22 accommodated in the flange pipe 15 is pushed into the pipe 11 together with the guide cylinder 21 as shown in FIG. At this time, the cable 25 is also fed toward the inside of the pipe line 11 by operating the handle 29 corresponding to the depression of the guide rod 20.
[0013]
The propulsion body 22 fed into the pipe 11 is separated from the guide tube 21 and starts in the axial direction of the pipe 11. Therefore, as the propulsion body 22 is propelled, the cable 25 is sent toward the inside of the pipe line 11 by operating the handle 29 in the same manner. The cable 25 enters the inside of the water-stopping case 18 from the outside by this feeding, and water-stopping in the water-stopping case 18 is performed as follows.
[0014]
That is, as shown in the figure, the control unit 43 that has received the information on the air pressure 41 and the water pressure 42 from the chamber 17 controls the regulator 38 to adjust the pressure of the pressurized air 34, so that the air 34 is piped. The water 39 rising from the passage 11 is pushed down to a predetermined level in the chamber 17. As a result, the upper portion of the chamber 17 and the inside of the water stop case 18 are filled with the pressurized air 34, and the water 39 does not enter. Part of the pressurized air 34 passes through the gap 35 between the outer periphery of the cable 25 and the inner periphery of the through hole 31, the packing 32, and the cap 33, and comes out of the cable insertion device 14. Thereby, the water 39 does not enter the penetration portion of the cable 25 in the water-stopping case 18, and therefore no water leakage occurs.
[0015]
In this way, the cable 25 is fed into the insertion device 14 in a water-stopped state in which water leakage is reliably prevented. However, although the packing 32 acts on the penetration portion of the cable 25 in the water-stopping case 18, the air 34 is passed through. Therefore, no harmful tightening force or the like that causes deformation is applied to the cable 25. Further, as described above, the packing 32 is made of natural leather, and therefore has an advantage that the sliding property with the outer surface of the cable 25 is good.
[0016]
When the inside view of the pipe is completed, the propulsion body 22 is returned to the inside of the original guide cylinder 21 by operating the handle 29 of the cable feed roller device 16 and pulling back the cable 25. Then, the guide rod 20 is pulled up, the propulsion body 22 is accommodated in the flange pipe 15 again, the sub valve 13 is closed, and the cable insertion device 14 is removed from the sub valve 13.
[0017]
FIG. 3 shows another embodiment of the present invention. Here, as shown in FIG. 3A, the differential pressure between the air pressure 41 and the water pressure 42 is input to the control unit 43 by the differential pressure gauge 45. Then, as shown in FIG. 3B, feedback control is performed to send the pressurized air 34 from the regulator 38 to the water stop case 18 so that the pressure indicated by the differential pressure gauge 45 becomes zero.
[0018]
4 and 5 show still another embodiment of the present invention. 1 and 2 and the one shown in FIG. 3, both the air pressure 41 and the water pressure 42 or the differential pressure between the two are input to the control unit 43. However, in FIG. 4 and FIG. In the apparatus, a water level sensor 51 associated with the chamber 17 is provided, and information regarding the level of the water surface 40 detected by the water level sensor 51 is supplied to the control unit 43. The control unit 43 controls the regulator 38 to adjust the pressure of the pressurized air 34 so that the level of the water surface 40 falls within a certain range in the vertical direction.
[0019]
One end of an air vent pipe 52 communicates with the upper portion of the chamber 17, and the other end of the air vent pipe 52 communicates with the atmosphere via an emergency valve 53. One end of a drain pipe 54 is connected to the lower part of the chamber 17, and the other end of the drain pipe 54 is communicated with the atmosphere via an emergency valve 55. The emergency valves 53 and 55 are configured to be opened and closed by a control unit 43 via a driver 56.
[0020]
FIG. 5 shows a block diagram of a specific example of control by the control unit 43. That is, the water level sensor 51 in FIG. 4 is capable of detecting the water level in the range of 0 to 1000 mm, and performs control by setting the water level 40 to the limit when the water level 40 drops to the limit and the water level 1000 mm when the level rises to the limit.
In FIG. 5, a control characteristic diagram by the control unit 43 is described in a block showing the control unit 43. In this characteristic diagram, the horizontal axis represents the water level, and the vertical axis represents the pressurization or depressurization request signal sent to the regulator 38. In this control unit 43, the target value of the water level is set to 500 mm.
[0021]
When the water level is 500 mm or in the vicinity thereof, the so-called equilibrium state is maintained without further pressurization or depressurization inside the chamber 17 and the water stop case 18. That is, the characteristic diagram coincides with the horizontal axis.
When the water level changes in the direction away from the vicinity of 500 mm upward or downward, the degree of pressurization or depressurization inside the chamber 17 and the water stop case 18 is changed according to the degree of the change. That is, the characteristic diagram is in an inclined state.
[0022]
When the water level changes greatly from the level of 500 mm, the pressurizing or depressurizing operation is performed up to the limit of the adjustment range by the regulator 38. That is, the characteristic diagram is parallel to the horizontal axis in a state of being farthest from the horizontal axis.
If the water level fluctuates until it approaches the level of 0 mm or 1000 mm, it is an emergency and it is not appropriate to fluctuate the water level beyond that. Therefore, the emergency valves 53 and 55 are opened and the air 34 or water 39 is opened. To the atmosphere. That is, when the water level 40 in the chamber 17 falls too low and the water level approaches 0 mm, the emergency valve 53 is opened via the driver 56 to release the air 34 from the air vent pipe 52 to the atmosphere. When the water level 40 in the chamber 17 rises too much and the water level approaches 1000 mm, the emergency valve 55 is opened via the driver 56 to release the water 39 from the drain pipe 54 to the atmosphere.
[0023]
【The invention's effect】
As described above, according to the present invention, the pressurized air is supplied to the portion communicating with the gap below the through hole in the case, and the pressure of the water rising from the inside of the pipe into the case and the pressure of the pressurized air Since the water surface is positioned where the two are balanced, the pressurized air supplied into the case enters the gap and the pressurized water in the pipe does not reach, so the space between the cable and the case Since the gap is formed between the cable and the through hole through which the cable passes, the cable is hardly subjected to substantial deformation when passing through the case. Therefore, this cable can be inserted into the pipe without causing a large deformation in the cable used for the endoscopic method.
[Brief description of the drawings]
FIG. 1 is a schematic configuration diagram of an in-pipe inspection apparatus according to an embodiment of the present invention.
FIG. 2 is an enlarged view showing a main part in FIG.
FIG. 3 is a diagram showing a main part of an in-pipe inspection apparatus according to another embodiment of the present invention.
FIG. 4 is a diagram showing a main part of an in-pipe inspection apparatus according to still another embodiment of the present invention.
FIG. 5 is a block diagram of a main part in FIG. 4;
[Explanation of symbols]
11 Pipe line 18 Water stop case 25 Cable 31 Through hole 34 Air 35 Clearance 37 Compressor 38 Regulator

Claims (1)

An in-pipe inspection apparatus comprising a cable insertion device provided upward from a pipe for inserting a cable from outside the pipe into a pipe filled with pressurized water, the cable insertion apparatus communicating with the pipe A case through which the cable is passed is provided, and a through-hole through which a cable from outside the tube is passed is formed in the wall portion of the case, and a gap is formed between the through-hole and the cable passed through the through-hole. The pressurized air is supplied to the portion communicating with the gap below the through hole in the case, and the pressure of the water rising from the inside of the pipe into the case is balanced with the pressure of the pressurized air An in-pipe inspection apparatus characterized in that means for positioning the water surface is provided.

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