Traction method

Abstract

To provide a traction device and a traction method capable of stopping rotation of a pulley when load torque exceeding operation torque is applied, capable of being used as assistance of manual traction since the operation torque can be changed, and capable of preventing a bobbin from being firmly clogged in an underground buried conduit.SOLUTION: A traction device 1 of the present invention is used for a conduit continuity test of an underground buried conduit 2, and includes a pulley 11 which tows a bobbin 3 passing through the underground buried conduit 2 and around which a rope 4 attached to the bobbin 3 is wound, an electric motor 12 which rotates the pulley 11, a rotation stopping means 13 which stops rotation of the pulley 11 when a load torque exceeding an operation torque is applied to the pulley 11, a torque setting means 14 which can change the operation torque, and a speed setting means 15 which sets a rotation speed of the electric motor 12.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention is a method for pulling a bobbin through an underground pipeline. Towing method Regarding. [Background technology]

[0002] A pipeline continuity test is performed by passing a bobbin (test piece) through an underground pipeline (Patent Documents 1 to 4). Patent Documents 5 and 6 disclose methods for laying cables in underground pipelines without applying load to the cables. As described in Patent Documents 1 to 6, the bobbin and cable are pulled by a power winch or manually. When towing a bobbin with a power winch, the bobbin may become stuck in the underground pipeline and must be dug up from the surface. However, there are some sites where digging is not possible, so bobbin jamming can be a major problem. Furthermore, when the cable is pulled by a power winch, an excessive load may be applied to the cable, resulting in damage to the cable. To prevent the bobbin from becoming firmly stuck in the underground pipeline, Patent Documents 7 and 8 propose retrieving the bobbin using a connector that can be separated when the pulling force exceeds a certain load. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 11-336987 [Patent Document 2] Japanese Patent Application Publication No. 3-38975 [Patent Document 3] Japanese Patent Application Publication No. 6-292313 [Patent Document 4] Utility Model Registration No. 3158695 [Patent Document 5] Patent Publication No. 2021-72656 [Patent Document 6] Japanese Patent Application Publication No. 2017-147773 [Patent Document 7] Japanese Patent Application Publication No. 2020-106108 [Patent Document 8] Japanese Patent Application Publication No. 2020-108296 Summary of the Invention [Problem to be solved by the invention]

[0004] However, in the methods proposed in Patent Documents 7 and 8, if the constant load that is the condition for connector separation is set too low, the connector will frequently separate. If the cable is deemed uninstallable due to connector separation, a great deal of work will be required to lay the cable. Furthermore, to perform the test again, the rope must be re-installed in the underground pipeline and the work must be repeated. On the other hand, if the constant load that is the condition for separating the connector is set too high, the bobbin will become tightly stuck in the underground pipeline.

[0005] Therefore, the present invention can stop the rotation of the pulley when a load torque exceeding the operating torque is applied, and can change the operating torque, so it can also be used as an aid to manual pulling, and can prevent the bobbin from becoming firmly stuck in the underground pipeline. Towing method The purpose is to provide the following. [Means for solving the problem]

[0006] Claim 1 The present invention as described Towing method teeth, A traction device 1 is used for a continuity test of an underground pipeline 2, and tows a bobbin 3 that passes through the underground pipeline 2, and includes a pulley 11 around which a rope 4 attached to the bobbin 3 is wound, an electric motor 12 that rotates the pulley 11, a rotation stopping means 13 that stops the rotation of the pulley 11 when a load torque exceeding the operating torque is applied to the pulley 11, a torque setting means 14 that can change the operating torque, and a speed setting means 15 that sets the rotation speed of the electric motor 12, and a powder clutch is used as the rotation stopping means 13.A traction method using a traction device 1, characterized in that the rope 4 is wound around the pulley 11, and the torque setting means 14 sets an initial torque that is lower than the operating torque, and after winding the rope 4 around the pulley 11, the operation switch 17 of the electric motor 12 is turned on at the initial torque, and after turning on the operation switch 17, the torque setting means 14 gradually increases the torque from the initial torque until the pulley 11 starts to move, and the torque when the pulley 11 starts to move is set as a reference torque, and the torque obtained by adding a predetermined ratio to the reference torque is set as the operating torque, and the traction device 1 is operated. Claim 2 The present invention as described Towing method teeth, A traction device 1 is used for a continuity test of an underground pipeline 2, and tows a bobbin 3 that passes through the underground pipeline 2, and includes a pulley 11 around which a rope 4 attached to the bobbin 3 is wound, an electric motor 12 that rotates the pulley 11, a rotation stopping means 13 that stops the rotation of the pulley 11 when a load torque exceeding the operating torque is applied to the pulley 11, a torque setting means 14 that can change the operating torque, and a speed setting means 15 that sets the rotation speed of the electric motor 12, and a powder clutch is used as the rotation stopping means 13. A towing method using the towing device 1 ,before The rope 4 is wound around the pulley 11, and the torque setting means 14 sets an initial torque that is lower than the operating torque; after the rope 4 is wound around the pulley 11, the operating switch 17 of the electric motor 12 is turned on at the initial torque; after the operating switch 17 is turned on, the torque setting means 14 gradually increases the torque from the initial torque until the pulley 11 starts to move; the torque at the time the pulley 11 starts to move is set as a reference torque, and the torque obtained by subtracting a predetermined ratio from the reference torque is set as the operating torque, and the traction device 1 is operated. Claim 3 The present invention as described is Claim 1 or Claim 2 The towing method according to the present invention is characterized in that the rotation speed of the electric motor 12 is set, and the towing device 1 is operated at the set rotation speed. [Effects of the Invention]

[0007] The present invention Towing method According to the invention, when a load torque exceeding the operating torque is applied to the pulley, the rotation of the pulley can be stopped, and the operating torque can be changed, so that it can also be used as an aid to manual pulling, and it is possible to prevent the bobbin from becoming firmly stuck in the underground pipeline. [Brief explanation of the drawings]

[0008] [Figure 1] A diagram showing the work process for underground pipeline continuity testing [Figure 2] Configuration diagram of the traction device according to this embodiment [Figure 3] 1 is a flowchart showing a towing method using the towing device according to this embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0009] The present invention No. 1 Embodiments of the present invention The towing method is A rope is wound around the pulley, and an initial torque that is lower than the operating torque is set by the torque setting means. After the rope is wound around the pulley, the operating switch of the electric motor is turned on at the initial torque. After the operating switch is turned on, the torque is gradually increased from the initial torque by the torque setting means until the pulley starts to move. The torque at which the pulley starts to move is set as the reference torque, and a torque obtained by adding a predetermined ratio to the reference torque is set as the operating torque, and the traction device is operated. According to this embodiment, When a load torque exceeding the operating torque is applied to the pulley, the rotation of the pulley can be stopped, and the operating torque can be changed, so that it can also be used to assist manual towing, and it can prevent the bobbin from becoming firmly stuck in the underground pipeline. Furthermore, according to this embodiment, by providing a speed setting means for setting the rotation speed of the motor, if the manual towing speed is too fast, a load is applied to the towing operation, so that an appropriate towing speed can be maintained. Furthermore, according to this embodiment, by using a powder clutch, torque can be easily changed. Furthermore, according to this embodiment, Since the operating torque can be set low, the bobbin can be prevented from becoming tightly clogged in the underground pipeline.

[0010] Second Embodiment of the Present Invention The towing method is A rope is wound around the pulley, and an initial torque that is lower than the operating torque is set by the torque setting means. After the rope is wound around the pulley, the operating switch of the electric motor is turned on at the initial torque. After the operating switch is turned on, the torque setting means gradually increases the torque from the initial torque until the pulley starts to move. The torque at which the pulley starts to move is used as the reference torque, and the operating torque is set to a torque obtained by subtracting a predetermined ratio from the reference torque, thereby operating the traction device. According to this embodiment, When a load torque exceeding the operating torque is applied to the pulley, the rotation of the pulley can be stopped, and the operating torque can be changed, so that it can also be used to assist manual towing, and it can prevent the bobbin from becoming firmly stuck in the underground pipeline. Furthermore, according to this embodiment, by providing a speed setting means for setting the rotation speed of the motor, if the manual towing speed is too fast, a load is applied to the towing operation, so that an appropriate towing speed can be maintained. Furthermore, according to this embodiment, by using a powder clutch, torque can be easily changed. Furthermore, according to this embodiment, It can also be used as a manual towing aid to prevent the bobbin from becoming tightly jammed in underground pipelines.

[0011] The present invention ThirdThe embodiment of the present invention is No. 1 or No. 2 In the traction method according to the embodiment, the rotation speed of the electric motor is set, and the traction device is operated at the set rotation speed. According to this embodiment, if the manual towing speed is too fast, a load is applied to the towing operation, thereby making it possible to maintain an appropriate towing speed. [Example]

[0012] An embodiment of the traction device according to the present invention will now be described. FIG. 1 is a diagram showing the work process for a pipeline continuity test of an underground pipeline. The traction device 1 according to this embodiment is used for a continuity test of an underground pipeline 2, and pulls a bobbin 3 passing through the underground pipeline 2.

[0013] As shown in FIG. 1( a ), a rope 4 is inserted into an underground pipeline 2 from a manhole A, and the tip of the rope 4 is led to a manhole B. As shown in Figure 1(b), in manhole B, the tip of rope 4 is attached to one end of bobbin 3. Sometimes brush 5 is attached to rope 4 together with bobbin 3. When brush 5 is attached together with bobbin 3, brush 5 is attached forward of bobbin 3 in the direction of travel. Another rope 6 is attached to the other end of bobbin 3, behind bobbin 3 in the direction of travel. After rope 4 and rope 6 are attached to bobbin 3, bobbin 3 is inserted into underground pipeline 2 and pulling of bobbin 3 begins. A traction device 1 is used to tow the bobbin 3. The traction device 1 is installed near the manhole A. By using the traction device 1 to pull the bobbin 3, the bobbin 3 moves within the underground pipeline 2 as shown in FIGS. 1(c), 1(d), and 1(e). As shown in FIG. 1(e), if the bobbin 3 can be moved to the manhole A side, the test result is passed, and the cable can then be laid.

[0014] If the bobbin 3 becomes stuck in the middle of the underground pipeline 2 as shown in FIG. 1(c) or FIG. 1(d), the rope 6 is pulled from the manhole B side to pull the bobbin 3. To cope with such a case, it is preferable to install another traction device 1 near the manhole B to tow the bobbin 3. In this way, if the bobbin 3 is pulled back from the manhole B side, it is determined that it is not possible to lay the cable from manhole B to manhole A, and a conduit continuity test will be performed from manhole A to manhole B.

[0015] Generally, the distance from manhole A to manhole B is about 500 m, and manual pulling is performed about 50 cm at a time, requiring about 100 manual pulling operations. The bobbin 3 used is about 40 cm to 60 cm long. The bobbin 3 has a diameter that is 1 cm to 2 cm smaller than the diameter of the underground pipeline 2. The diameter of the underground pipeline 2 is about 15 cm to 25 cm. Since the underground pipeline 2 that requires such a pipeline continuity test has been installed for a considerable amount of time, blockages and distortions have occurred inside the underground pipeline 2, and it is not uncommon for the bobbin 3 to become clogged.

[0016] 2A and 2B are block diagrams of the towing device according to the present embodiment, in which FIG. 2A is a block diagram showing the towing device in terms of functional implementation means, FIG. 2B is a side view of the main parts of the towing device, and FIG. 2C is a top view of the main parts of the towing device.

[0017] The traction device 1 of this embodiment comprises a pulley 11 around which a rope 4 attached to a bobbin 3 is wound, an electric motor 12 that rotates the pulley 11, a rotation stopping means 13 that stops the rotation of the pulley 11 when a load torque exceeding the operating torque is applied to the pulley 11, a torque setting means 14 that can change the operating torque, a speed setting means 15 that sets the rotation speed of the electric motor 12, a display means 16 that displays the torque and rotation speed, an operation switch 17 that turns the operation of the electric motor 12 ON and OFF, and a rotation transmission means 18 that is arranged between the output shaft of the rotation stopping means 13 and the pulley 11. A powder clutch is used as the rotation stopping means 13. A torque volume is used as the torque setting means 14. A worm reducer is used as the rotation transmitting means 18.

[0018] 2(b) and 2(c), the electric motor 12, the rotation stopping means 13, and the rotation transmitting means 18 are arranged so that the rotation axes of the electric motor 12 and the rotation stopping means 13 and the input shaft of the rotation transmitting means 18 are on a straight line, and the output shaft of the rotation transmitting means 18 is oriented in a direction perpendicular to the rotation axes of the electric motor 12 and the input shaft of the rotation transmitting means 18, and the pulley 11 is arranged on the output shaft of the rotation transmitting means 18. This makes it possible to reduce the size of the traction device 1 and provides excellent stability against the tensile force applied to the pulley 11 when the bobbin 3 is towed.

[0019] According to the traction device 1 of this embodiment, when an operating torque is applied to the pulley 11, the rotation of the pulley 11 can be stopped and the operating torque can be changed, so it can also be used to assist manual traction and prevent the bobbin 3 from becoming firmly stuck in the underground pipeline 2. Furthermore, according to the towing device 1 of this embodiment, by providing a speed setting means 15 for setting the rotation speed of the electric motor 12, if the manual towing speed is too fast, a load is added to the towing operation, thereby making it possible to maintain an appropriate towing speed. Furthermore, according to the traction device 1 of this embodiment, torque can be easily changed by using a powder clutch.

[0020] FIG. 3 is a flowchart showing a towing method using the towing device according to this embodiment. First, the rope 4 is wound around the pulley 11 (S21), the rotation speed of the electric motor 12 is set (S22), and an initial torque that is lower than the operating torque is set by the torque setting means 14 (S23). The rotation speed in S22 is set so that the pulling speed is in the range of 1 m / min to 27 m / min, more preferably in the range of 1 m / min to 10 m / min. Furthermore, for the initial torque in S23, it is preferable to set the torque volume to 0%. After setting the initial torque in S23, the operation switch 17 of the electric motor 12 is turned ON at the initial torque (S24), and after the operation switch 17 is turned ON, the torque setting means 14 gradually increases the torque from the initial torque until the pulley 11 starts to move (S25).

[0021] The torque is increased by S25 until the pulley 11 starts to move (No in S26), and when the pulley 11 starts to move (Yes in S26), the torque increase by S25 is stopped and the operation switch 17 is turned OFF (S27). The torque when the pulley 11 starts to move is set as a reference torque (S28), and the operating torque is set based on the reference torque (S29).

[0022] There are two methods for setting the operating torque using S29. One is to set the operating torque to a torque obtained by adding a predetermined ratio to the reference torque. By setting the operating torque to a torque obtained by adding a predetermined ratio to the reference torque, the operating torque can be set low, which prevents the bobbin 3 from becoming tightly clogged in the underground pipeline 2. The other is to set the operating torque to a torque obtained by subtracting a predetermined ratio from the reference torque. By setting the operating torque to a torque obtained by subtracting a predetermined ratio from the reference torque, it can also be used to assist manual towing, and can prevent the bobbin 3 from becoming firmly stuck in the underground pipeline 2. After the operating torque is set in S29, the operation switch 17 is turned on (S30) and the pulling of the bobbin 3 begins.

[0023] According to the towing method using the towing device 1 of this embodiment, the towing device 1 is operated at a set rotational speed, so if the manual towing speed is too fast, a load is added to the towing operation, making it possible to maintain an appropriate towing speed. [Industrial Applicability]

[0024] The present invention can also be used as a traction device for traction of a cable laid in an underground pipeline, and can prevent damage to the cable by preventing excessive load from being applied to the cable due to traction. [Explanation of symbols]

[0025] 1 Traction device 2 Underground pipeline 3 bobbins 4, 6 rope 5 Brushes 11 Pulley 12 Electric motor 13 Rotation stopping means 14 Torque setting means 15 Speed ​​setting means 16 Display means 17 Operation switch 18 Rotation transmission means A, B manholes

Claims

1. A traction device used for a continuity test of an underground pipeline, which traction device traction a bobbin passing through the underground pipeline, a pulley around which a rope attached to the bobbin is wound; an electric motor that rotates the pulley; a rotation stopping means for stopping the rotation of the pulley when a load torque exceeding an operating torque is applied to the pulley; a torque setting means for changing the operating torque; a speed setting means for setting the rotation speed of the electric motor; Equipped with A powder clutch is used as the rotation stopping means. A towing device characterized by:

2. A towing method using the towing device according to claim 1, Winding the rope around the pulley, The torque setting means sets an initial torque that is lower than the operating torque, After winding the rope around the pulley, turn on the operation switch of the electric motor with the initial torque; After the operation switch is turned on, the torque setting means gradually increases the torque from the initial torque until the pulley starts to move; The torque when the pulley starts to move is set as a reference torque, and the torque obtained by adding a predetermined ratio to the reference torque is set as the operating torque to operate the traction device. A towing method characterized by the above.

3. A towing method using the towing device according to claim 1, Winding the rope around the pulley, The torque setting means sets an initial torque that is lower than the operating torque, After winding the rope around the pulley, turn on the operation switch of the electric motor with the initial torque; After the operation switch is turned on, the torque setting means gradually increases the torque from the initial torque until the pulley starts to move; The torque when the pulley starts to move is set as a reference torque, and the torque obtained by subtracting a predetermined ratio from the reference torque is set as the operating torque to operate the traction device. A towing method characterized by the above.

4. setting a rotational speed of the electric motor; Operate the traction device at the set rotational speed.

4. The towing method according to claim 2 or 3.

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