JP4102372B2 - Attaching the protective net to the steel tower - Google Patents

Description

  The present invention is in operation on a steel tower in which a number of steel tower components mainly made of steel are successively arranged in the height direction, such as a steel tower in an electric facility and a telecommunication facility, and a wireless tower such as an antenna for mobile communication. Further, the present invention relates to a method for attaching a protective net to a steel tower, to which a protective net for preventing a worker from falling or a material or tool from falling during work is attached.

  In recent years, there is an urgent need to construct a high-speed and large-capacity information communication network in order to cope with mobile communication such as Internet connection services and mobile phones. For this reason, work is underway to install electrical facilities such as power lines and power lines for wireless telecommunications facilities and related equipment on steel towers. This work involves installing equipment such as antennas at the top of the tower and drawing in cables such as power lines and power lines from the tower to the power control building. Many work is performed on the tower. Is called.

  In addition, before performing these operations, it is necessary to attach a protective net to the entire work area at intervals of about 5 m from the top of the steel tower to the base to prevent the operator from falling or the material or tool from falling. In this way, the installation interval of the protective net is set to 5 m because the fall speed at the time of falling becomes too fast if the height difference is wide enough, so even if it is received by the protective net, it will be extended by the load of the human body, This is because there is a high possibility that the human body will come into contact with the steel tower structure, and the damage to the worker can be great and can be fatal.

  By the way, when the types of steel towers are classified according to their shapes, a plurality of pillars are arranged, a polygonal (mainly triangular, quadrilateral) type whose section is a polygonal shape, and a type consisting of one pillar (hereinafter, circular). First, let's look at how to attach a protective net to a polygonal steel tower.

  Conventionally, the work of attaching the protective net is generally performed by an operator climbing to the top of the steel tower and attaching it to the foundation at an interval of about 5 m in order from the work position of the top. This protective net is generally formed by knitting a net of nylon fiber or the like from about 3 m square to about 5 m square, and each apex is similarly provided with a connection string of nylon fiber or the like.

  The worker raises the protective net one by one from the ground base to the place where the protective net is attached, or pulls it up to the work table above the tower, etc., and pulls it down to connect the connection string one by one. Tie to structural beams and pillars. In this way, the protective net is stretched inside the steel tower (the portion surrounded by the plurality of columns).

However, in order to install this protective net, it was necessary to ensure the safety of the workers using a parent net, a parent rope and an auxiliary rope, which was a very time-consuming and inefficient operation. For this reason, the following patent document proposes a method for attaching a protective net that can attach the protective net in a short time.
JP 2004-194867 A

  As shown in FIG. 23, first, the vertical rope 41 to which the connection cords 63 and 64 at the two vertices of the protective net 44 can be attached is pulled up to the top of the tower 40, and then the other two vertices of the protective net 44 are connected. The connecting cords 61 and 62 are attached to the steel tower structure of the tower 40, and then the vertical rope 41 is pulled to the vertical ladder A side with the operating rod, and then the connecting cords 63 and 64 are attached to the vertical rope 41. It attaches to 42 hook metal fittings 45. This eliminates the need for the operator to walk through beams, braces, columns, etc., and move laterally to the opposite side of the vertical ladder, so that the protective net can be attached in a short time.

  On the other hand, when looking at how to attach a protective net to a circular type steel tower, conventionally, a net that opens in a fan shape is stretched over multiple aggregates below the work position on the power pole, and the base end of the net is connected to the power pole. There is something that is wrapped around and fixed with a band.

  However, with such a protective net, when a fallen object jumps outward, it cannot be reliably received, and there is a risk of contact with a passerby under the tower. In particular, when it is attached to a circular type steel tower, there are circumstances in which it is difficult to apply as it is because the diameter of the column is small.

For such things, a protective net that can easily be mounted and removed from a pillar of a circular type tower such as a mobile communication antenna, can be configured compactly, and can catch falling objects going outwards is as follows. In the patent literature.
JP 2003-258514 A

  As shown in FIG. 24, the protective net 1 is composed of upper and lower mounting brackets 2, an upper support member 3, a lower support member 4, and a net body 5. The mounting bracket 2 is configured such that the chain is locked to both ends of the mounting frame that comes into contact with the steel pipe column P and is fastened with a tightening member. The upper and lower support members 3, 4 project three support rods 16 radially from the mounting frame in the horizontal direction around the steel pipe column P, and respectively connect the annular rods 17 to the tip portions thereof. The annular rod 17 is engaged with the upper and lower ends of the net body 5 to form the net body 5 in a cylindrical shape, and is configured to surround an operator who performs installation work for the mobile communication antenna. The lower end portion of the net body 5 is wound around the steel pipe column P and tied and locked with the rope R so as to receive the fallen object during the work.

  However, it is known in advance that many tasks are performed on the tower, such as installing an antenna or other device on the tower, or pulling cables such as power lines and power lines from the tower to the power control building. As shown in Patent Document 2, it is unreasonable to attach a protective net to a steel tower before each work on the steel tower, and it can be said that a lot of time is required.

  Further, in the method of attaching the protective net shown in Patent Document 2, since many of the operations for attaching the protective net are performed on the steel tower, it is considered that a crash may occur during the installation of the protective net. However, there is still room for improvement from the viewpoint of reducing the number of crashes.

  In addition, when attaching a protective net to a polygonal steel tower, as shown in Patent Document 1, the place where the net is stretched has been limited to the inside of the steel tower surrounded by a plurality of pillars, but 90% of the steel tower work takes place in the tower. Since it is an outside work (all bolts are facing outwards, they work out), the effectiveness rate is 10% or less. For this reason, the conventional method of laying a protective net is insufficient as a safety measure.

  In addition, an overhang net (so-called morning glory) is often applied to the outermost part of the bottom of the tower, but this is only for falling objects, not for people, but when the operator falls from the top of the tower, the fall distance Therefore, the impact is large and the safety of the worker cannot be ensured.

  By the way, the reason why the net has not been stretched outside the tower is that, in order to stretch the net outside the tower, assembly of the scaffold is required, and the conventional technology costs about the same amount as the tower assembly. The construction of the scaffolds is also associated with danger, and the overall risk does not decrease.

  The object of the present invention is to eliminate the inconveniences of the above-mentioned conventional example, and to install a protection net for preventing a fall accident and a fall accident due to work on the tower at a low cost and rationally. To a tower with a protective net installed around the tower to reduce the risk of a crash and reduce the risk of a crash, and to prevent a crash outside the tower It is in providing the attachment method of the protection net | network.

In order to achieve the above object, the invention according to claim 1 is a protection in which an opening through which a steel tower penetrates is formed in a frame having a ring shape larger than the outer periphery of a steel tower having a polygonal cross section having a plurality of columns. Each time a tower is assembled, a frame with a protective net is covered from the top of the tower , and one end of the frame is wound around a pillar and suspended by a connecting member that is a rope connecting the other end to the frame. The gist is that the protective net is stretched around the steel tower by fixing the inner net inside the tower and connecting the inner net and the protective net to close the opening of the protective net. It is what.

  According to the first aspect of the present invention, a protective net having an opening at the center is attached to a frame having an annular shape larger than the outer periphery of the steel tower, and this is attached to the steel tower so as to block the opening of the protective net. Therefore, the protection net can be stretched so as to prevent not only a crash occurring inside the tower surrounded by a plurality of support columns but also a crash caused by work outside the tower, which occupies most of the work on the tower. Even in the case of a single-pillar steel tower, all the work performed on the steel tower can be said to be work outside the steel tower, so this action also applies to the single-pillar steel tower.

  In addition, since the protective net was attached to the ring-shaped frame in advance, the frame with the protective net was put on the top of the steel tower and connected to the steel tower while assembling the steel tower. The work can be carried out, and the labor and cost of assembling a scaffold for attaching the protective net are not generated and the cost is low.

  In addition, since the assembly of the frame and the installation of the protective net to the frame can be performed on the ground in advance, the frame with the protective net is covered with a crane from the top of the tower, and then the frame is connected to the steel tower. It is only necessary to perform the work of closing the opening on the steel tower, and compared to the conventional case of building a scaffold for attaching the protective net, the work to be done at a high place is reduced and the risk of a crash accident occurring. It can be reduced.

  And since the protection net was attached to the steel tower at the same time as the assembly of the steel tower in this way, after assembling the steel tower, it would be necessary to perform various operations on the steel tower. This is more reasonable than when a protective net is attached immediately before each operation.

  Also, inside the steel tower surrounded by a plurality of pillars, an internal net was stretched as in the past, and the opening of the protective net was closed by binding the internal net and the protective net. There is no need to route the protective net attached from the outside of the tower to the inside of the tower, and the inside and outside of the tower can be reliably and easily covered with each net.

  Moreover, the length of a connecting member can be flexibly adjusted according to the distance between the support | pillar of a steel tower, and a flame | frame by adjusting the length of the rope wound around a support | pillar or tied to a flame | frame.

According to the second aspect of the present invention, the vertical net covering the outer periphery of the tower is attached to the frame with the protective net except the frame with the lowermost protective net together with the protective net, and the frame with the vertical net and the protective net is attached to the steel tower. After attaching to the frame, the lower end of the vertical net is bonded to the frame with the lower protective net, and the frame with the upper and lower protective nets is covered with the vertical net.

  According to the second aspect of the present invention, even when working on a steel tower installed at a place where there is a lot of traffic other than the operator, such as a road or a nearby site of a house, a vertical net that covers between the upper and lower frames Forms a closed space and encloses all fallen objects, so it is possible to reliably prevent accidents caused by falling objects hitting people passing under the steel tower.

  According to the third aspect of the present invention, the frame is constituted by a plurality of tubular members, and another tubular member is inserted into one tubular member, or one tubular member and another tubular member are partially overlapped. In addition, the gist is to make it extendable by fixing each other with a detachable bolt.

  According to the third aspect of the present invention, even if the outer periphery is different between the upper part and the lower part of the steel tower, the size of the frame can be increased by changing the fixing position of the bolt to the tubular member to expand and contract the frame. The height can be adjusted to the outer periphery of each part of the steel tower to which the protective net is attached. Thereby, the distance from the outer peripheral surface of a steel tower to a flame | frame can be set appropriately, and a protection net | network can be stretched | stretched in appropriate width.

  According to a fourth aspect of the present invention, the rope includes a hook at one end, and the other end of the rope is wound around the frame and fixed so as to pass through the first anti-slip fitting. The one end with the hook is wound around the support bolt provided on the pillar of the steel tower, and the hook is fixed to the second anti-slip fitting through which the rope penetrates. It is.

  According to the fourth aspect of the present invention, if the rope wound around the frame is fixed so as to sew on the first anti-slip hardware, one end provided with the hook of the rope is attached to the tower column. By simply winding and hooking this hook on the second anti-skid hardware that the cord penetrates, it is possible to connect the column and the frame easily without using complicated members. Can be linked. In addition, when the rope is wound around the column, the rope is passed over the scaffold bolt provided in the column, so that the vertical position of the rope can be fixed without using a separate member.

  The method of attaching a protective net to a steel tower of the present invention can attach a protective net to a steel tower at a low cost and reasonably to prevent a fall accident and a fall accident due to work on the steel tower. Reduce the risk of crashes by reducing work at the site, and also install a protective net around the tower to prevent accidents outside the tower where accidents are likely to occur be able to.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a front view showing an annular frame (hereinafter referred to as an annular frame) used in the first embodiment of the method for attaching a protective net to a steel tower of the present invention.

  The annular frame 20 is a frame that supports a protective net used for a square-type steel tower in which pillars are arranged in a square cross section, and includes a square frame 10 made of a metal pipe, a first support frame 11, and a second support frame. 12.

  As shown in FIG. 2, the corner frame 10 is constructed by bending a metal pipe gently so as to form an angle of 90 degrees, and the length of one side is 2000 mm. Further, as shown in FIG. 3, the first support frame 11 is a straight metal pipe having a length of 3660 mm, and the second support frame 12 is made of a straight metal having a length of 3620 mm as shown in FIG. It is a pipe.

  Further, a bolt hole is formed at a predetermined position from the end of each member. For example, a long hole 10a is formed on both ends at a position 150 mm from the end of the square frame 10, and a long hole 11a is formed on both ends at a position 400mm from the end of the first support frame 11. Holes 12a are formed on both ends at positions of 60 mm, 660 mm, and 1260 mm from the ends of 12, respectively.

  Here, the outer diameter of the metal pipe constituting the corner frame 10 and the first support frame 11 is 47.8 mm, the inner diameter is 42.8 mm, and the outer diameter of the metal pipe constituting the second support frame 12 is 41.9 mm. The inner diameter is 36.9 mm, both ends of the second support frame 12 are fitted into the square frame 10 and the first support frame 11, respectively, and the positions of the long holes 10a, 11a and the hole 12a are aligned with screws. The annular frame 20 is assembled by fixing.

  Since the second support frame 12 is provided with holes 12a at a plurality of positions from both ends, the length of one side of the annular frame 20 can be reduced from 4800 mm by adjusting the positions of the long holes 10a and 11a and the holes 12a of each member. Up to 6630mm, it can be changed freely.

  A state where the protective net is attached along the annular frame 20 formed as described above and attached to the steel tower will be described. As shown in FIG. 5, the protective net 9 is, for example, a polyester Russell net having a mesh size of 15 to 100 mm, and has an opening 9a at the center and an edge rope 9b made of nylon around. In addition, the size of the annular frame 20 is adjusted by expanding and contracting so as to be larger than the outer periphery at the mounting position of the steel tower. Then, the protection net 9 is attached by binding the edge rope 9b along the annular frame 20 on the ground, and further bundled with a separately prepared string 9c and tied to the annular frame 20.

On the ground, a connecting string 14 for hanging the annular frame 20 as a connecting member is attached to the annular frame 20 in advance. As shown in FIG. 6, the connecting string 14 is a nylon string, for example, and is provided with an openable hook 14a at one end.

  When the connection string 14 is attached to the annular frame 20 and the pillar of the steel tower, a first anti-skid fitting 50 shown in FIG. 7 and a second anti-slip fitting 51 shown in FIG. 8 are further used.

  As shown in FIG. 7, the first anti-slip fitting is a substantially triangular metal plate having three holes 50 a sized to allow the connecting string 14 to pass therethrough. Further, as shown in FIG. 8, the second anti-slip fitting is formed by bending a metal plate into a U-shape and drilling holes 51a on both sides so that the connecting string 14 can pass therethrough.

  When attaching the connecting string 14 to the annular frame 20, as shown in FIG. 5, with the connecting string 14 passing through one of the holes 51 a of the second anti-slip fitting 51 in advance, The other end of the connecting string 14 (the opposite end of the hook 14a) is wound around one of the holes a of the stopper 50, and is further wound around the annular frame 20 and penetrated and fixed to the remaining two holes 50a. A total of eight such connecting strings 14 are attached to both sides sandwiching each corner of the annular frame 20, for example.

  Next, as shown in FIG. 9, this is attached to the steel tower 30 in the middle of an assembly. The steel tower 30 is a square-type steel tower having four columns 30a, and is constructed by assembling a plurality of steel tower components. In FIG. 9, the steel tower 30 is in the process of assembling. When the steel tower 30 is assembled to an appropriate position, the suspension rope 8 is attached to the annular frame 20, and the annular frame 20 is lifted by the crane truck 7 and covered on the steel tower 30.

  Next, the hanging rope 8 is removed from the annular frame 20, and the connecting string 14 is fixed to the steel tower 30. As shown in FIG. 10, the end of the connecting string 14 on the side provided with the hook 14a is wound around the column 30a of the tower 30, and the hook 14a is attached to the remaining hole 51a of the second anti-slip fitting 51 that has been penetrated in advance. Multiply. Since the second anti-slip fitting 51 is bent in a U-shape, the hole 51a is inclined with respect to the connecting string 14 by being pulled by the hook 14a, and the hook 14a is hung on the connecting string 14 as it is. Compared to, it is less slippery and can be fixed stably.

  Further, when the connecting string 14 is wound around the support column 30a, the connecting string 14 passes over the scaffold bolt 30b included in the support column 30a as a scaffold for lifting the operator. Thereby, even if it does not use a member separately, it can prevent that the connection string 14 slides down in the direction of gravity, and can fix an up-and-down position.

  Next, the string that bundled the protection net 9 is unwound, and the protection net 9 is drawn toward the steel tower 30 side. At this time, the protection net 9 may be closed by cutting the protection net 9 into the tower 30 so as to avoid the support column 30a and binding the opening 9a with a string. In consideration of raising and lowering, as shown in a second embodiment to be described later, an internal net providing an opening / closing type lifting / lowering opening is stretched in advance at the attachment position of the protection net 9 of the tower 30 to open the protection net 9. The part and the internal net may be bound.

  FIG. 11 shows a state where the above operation is repeated and the assembly of the tower 30 and the installation of the protective net 9 are completed. The distance between the upper and lower protective nets 9 is set to 5 m or less so that the impact when the operator falls is not increased. In addition, the size of the annular frame 20 is set to be larger than the outer periphery at the mounting position of the tower 30. However, as will be described later, the outer periphery of the tower 30 is reduced in consideration of pulling down the protective net 9 later. It may be larger than the size of the outer periphery at the lowest lower end.

  Next, a second embodiment of the method for attaching the protective net to the steel tower of the present invention will be described. FIG. 12 is a front view of an annular frame that supports a protective net used in a triangular type steel tower in which support columns are arranged in a triangular cross section. Similar to the first embodiment, the annular frame 21 is constituted by each member made of a metal pipe, but the bending angle of the corner frame 13 constituting the corner is 60 degrees.

  The annular frame 21 includes a corner frame 13 made of a metal pipe, a first support frame 11 and a second support frame 12 that are the same as those in the first embodiment. As shown in FIG. 13, the corner frame 13 is formed by bending a metal pipe gently so as to form an angle of 60 degrees, and the length of one side is set to 900 mm. Moreover, the hole 13a is drilled at both end sides at a position 110 mm from the end.

  The metal pipe constituting the corner frame 13 has an outer diameter of 31.8 mm and an inner diameter of 29.0 mm. One end of the second support frame 12 is fitted into the first support frame 11 and both ends of the corner frame 13 are connected to the second end. (2) The annular frame 21 is assembled by fitting into the other end of the support frame 12, aligning the positions of the long holes 11a and the holes 12a and 13a, and screwing them with bolts.

  Then, by adjusting the positions of the long holes 11a and the holes 12a and 13a of the respective members, the length of one side of the annular frame 21 can be expanded and contracted from 4787 mm to 5987 mm.

  FIG. 14 shows a state in which the protective net is attached along the annular frame 21 formed in this way and attached to the steel tower. The protective net 9 is, for example, a polyester raschel net having an opening at the center and an edge rope around the same as in the first embodiment. The size of the annular frame 21 is adjusted by expanding and contracting so that the annular frame 21 is larger than the outer periphery of the steel tower 30 at the attachment position. Then, the protective net 9 is attached along the annular frame 21 on the ground, and bundled with a string (not shown) and tied to the annular frame 21.

  A connecting rod 15 as a connecting member for connecting the annular frame 21 and the steel tower 31 is attached to the corner of the annular frame 21. The connecting rod 15 is configured, for example, by providing a clamp (not shown) that holds the annular frame 21 at one end and a clamp (not shown) that holds the column 31a of the steel tower 31 at the other end. This operation is also performed on the ground.

  Next, before attaching this to the steel tower 31 in the middle of assembly, an internal net is stretched in advance inside the steel tower 31 where the protective net 9 is attached. As shown in FIG. 15, the internal net 6 is a polyester Russell net having a mesh size of 15 to 100 mm, for example, and has the same triangular shape as the space surrounded by the columns 31 a of the steel tower 31. A nylon binding string (not shown) is provided around the periphery, and an opening / closing lift 6a is provided at one corner.

  The openable lift 6a is formed, for example, with an opening having a size that allows an operator to pass near the corner of the internal net 6, and by arranging a triangular covering net so as to cover the opening. Two sides of the internal net 6 sandwiching the part and two sides of the covering net are overlapped and bonded.

  Then, after the inner net 6 is arranged at the attachment position of the protection net 9 of the tower 31 and is bound and stretched to the column 31a of the tower 31 by the binding string, as shown in FIG. An annular frame 21 to which a protective net 9 is attached is disposed from above.

  The steel tower 31 is a triangular type steel tower having three columns 31a, and is constructed by assembling a plurality of steel tower components. In FIG. 9, the steel tower 31 is in the process of assembling. When the steel tower 31 is assembled to an appropriate position, the suspension rope 8 is attached to the annular frame 21, and the annular frame 21 is lifted by the crane vehicle 7 so as to cover the steel tower 31.

  Next, the suspension rope 8 is removed from the annular frame 21, and is attached to the column 31 a of the steel tower 31 by the connecting rod 15. Then, the string bundled with the protective net 9 is unwound, the protective net 9 is drawn toward the tower 31 side, and the opening of the protective net 9 and the internal net 6 are connected by a binding string (not shown). The opening of 9 is closed.

  Further, as shown in FIG. 16, in a site where the steel tower 31 is close to a road or a house, it is preferable that the vertical net 33 covers the periphery of the steel tower 31 to wrap all fallen objects.

  First, when attaching the protective net 9 to the annular frame 21 on the ground, the vertical net 33 is also attached to the annular frame 21, and the nets 9, 33 are bundled and tied to the annular frame 21. I'll add it. Since the vertical net 33 is stretched between the upper and lower annular frames 21 as will be described later, it is not necessary to attach the vertical net 33 to the lowermost annular frame 21.

  As will be described later, when the vertical net 33 is transferred to the annular frame 21 in consideration of removing the vertical net 33 later, the annular frame 21 is not passed through the mesh of the vertical net 33, but the annular frame 21 is passed through. Attach to 21 with a string.

  Then, as shown in FIG. 9, the annular frame 21 is attached to the steel tower 31 in the same manner as before, the string that bundles the nets 9 and 33 is unwound, and the protective net 9 is stretched, as shown in FIG. Then, the vertical net 33 is lowered and the lower end thereof is attached to the annular frame 21 located on the lower side.

  As a result, not only the vertical direction of the tower 31 but also the horizontal direction can be covered, and it is possible to prevent an accident caused by a worker falling or a work tool falling wherever work is performed on the tower 31. In this case, the work site is covered in all directions by the protective net 9, the internal net 6, and the vertical net 33, but the worker moves in the steel tower from the open / close lift 6 a of the internal net 6. I can do it.

  By the way, as a method of connecting the annular frame to the steel tower, the connecting string 14 is used as described in the first embodiment, or the connecting rod 15 is used as described in the second embodiment. You may make it bind.

  As shown in FIG. 17, after the triangular annular frame 21 is assembled and the transfer rod 36 is screwed and fixed so as to connect the two sides of the annular frame 21, the protective net 9 and the vertical net 33 are attached and bundled with a string. Keep it. Then, it is lifted by a crane 7 as shown in FIG. 9 and moved onto a steel tower 31 that is being assembled.

  Here, a partition space 36a is formed in the annular frame 21 by the corner portion and the transfer rod 36, and the annular frame 21 is lowered so that each column 31a of the steel tower 31 is inserted into each partition space 36a. . Then, the transfer rod 36 comes into contact with the beam 35 of the tower 31 and the annular frame 21 is placed on the beam 35.

  Then, the annular frame 21 and the steel tower 31 are connected by connecting the transfer rod 36 and the beam 35 with a rope (not shown) or the like. After that, as described above, the string that bundles the protective net 9 and the vertical net 33 is unwound, the protective net 9 and the internal net 6 are connected, the opening of the protective net 9 is closed, and the vertical net 33 is lowered. The lower end is bonded and fixed to the lower annular frame 21.

  By the way, the vertical net 33 is more affected by the wind than a net stretched horizontally as in the prior art, and reduces the impact when an operator who has fallen from the steel tower is received by the protective net 9. When the protective net 9 is stretched with a margin, the protective net 9 itself is easily affected by the wind. However, the nets 9 and 33 can be easily applied to the nets 9 and 33 in a strong wind as follows. Can be cured and removed.

  The triangular type steel tower 31 will be described as an example. First, as shown in FIG. 18, a binding string 38 that binds the upper end of the vertical net 33 extending between the upper and lower annular frames 21 to the upper annular frame 21 is provided on the upper stage. An operator (not shown) on the side of the annular frame 21 releases.

  Next, as shown in FIG. 19, the upper end of the vertical net 33 is bound to the end of the rope 39 held by the operator on the upper annular frame 21 side by the binding strap 38, and the rope 39 is unwound while being pulled out. The vertical net 33 is wound down from the annular frame 21 toward the lower annular frame 21.

  When all the vertical nets 33 are lowered to the lower annular frame 21, as shown in FIG. 20, an operator (not shown) on the lower annular frame 21 side binds and binds the vertical net 33 to the lower annular frame 32, Fix it. Then, as shown in FIG. 21, the opening of the protective net 9 is further unblocked, and the protective net 9 is moved toward the annular frame 21 and tied to the annular frame 21 and fixed.

  In this way, the vertical net 33 and the protective net 9 are not strongly affected by the wind. And since the operator performs the work on the steel tower 31 only by unbinding the nets 9 and 33 and bringing the nets 9 and 33 to the one annular frame 21 side and bundling them, it is necessary to perform many complicated operations. There is no.

  After that, when removing the vertical net 33 and the protective net 9, the rope 37 held by the worker 19 on the ground is held in a state where the nets 9 and 33 are bound and tied to the annular frame 21 as described above. It is attached to the annular frame 21 over the pulley 18 attached to the lower side of the antenna 29.

  Thereafter, a worker (not shown) on the steel tower 31 removes the connecting rod 15, and the ground worker 19 pulls out the rope 37 to lower the annular frame 21. This operation is repeated, and the annular frames 21 are lowered one by one.

  As a result, the protective net 9 and the vertical net 33 can be completely removed. In addition, since the operator performs the work on the steel tower 31 to remove both the nets 9 and 33 only by linking the rope 37 to the annular frame 21 and removing the connecting rod 15, it is not necessary to perform many complicated operations. .

  If the rope 37 for lowering the annular frame 21 is also used as the rope 39 used when unwinding the vertical net 33, the work performed on the steel tower 31 can be further reduced. At this time, since the weight of the annular frame 21 to which the nets 9 and 33 are bound is about 50 kg per piece, a rope that can withstand the load is used when the nets 9 and 33 are later removed. Then, the vertical net 33 is rolled down.

  In the case where both nets 9 and 33 are scheduled to be removed later, it is preferable that the pulley 18 is attached to the lower side of the antenna 29 in advance when the steel tower 31 is assembled.

It is a front view which shows the annular frame used for 1st Embodiment of the attachment method of the protection net to the steel tower of this invention. It is a front view of the corner | frame frame which comprises the cyclic | annular frame in 1st Embodiment. It is a front view of the 1st support frame which constitutes an annular frame. It is a front view of the 2nd support frame which constitutes an annular frame. It is an enlarged view which shows the part of the annular frame to which a protection net | network and a connection string are attached. It is a front view of a connection string. It is a front view of the 1st antiskid metal fitting. It is a perspective view of the 2nd antiskid metal fitting. It is a side view which shows 1st Embodiment of the attachment method of the protection net to the steel tower of this invention. It is the elements on larger scale of the support | pillar which attaches a connection string. It is a side view which shows the state which attached the protection net. It is a front view which shows the cyclic | annular flame | frame used for 2nd Embodiment of the attachment method of the protection net to the steel tower of this invention. It is a front view of the square frame which comprises the annular frame in 2nd Embodiment. It is a side view which shows 2nd Embodiment of the attachment method of the protection net to the steel tower of this invention. It is a cross-sectional front view which shows the steel tower which extended the protection net. It is a whole side view which shows the steel tower which extended the protection net | network and the vertical net | network. It is explanatory drawing which shows the other method of attaching an annular frame to a steel tower. It is explanatory drawing which shows the 1st step of the removal method of a perpendicular | vertical net. It is explanatory drawing which shows the 2nd step of the removal method of a perpendicular | vertical net. It is explanatory drawing which shows the 3rd step of the removal method of a perpendicular | vertical net. It is a whole side view showing the state where a vertical net and a protection net were bundled and cured. It is a side view which shows the method of removing a vertical net | network and a protection net | network. It is a perspective view which shows the attachment method of the conventional protection net. It is a side view which shows the other attachment method of the conventional protection net | network.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Protective net 2 Mounting bracket 3 Upper support member 4 Lower support member 5 Net main body 6 Internal net 6a Opening and closing type lift 7 Mobile crane 8 Hanging rope 9 Protective net 9a Opening 9b Edge rope 9c String 10 Square frame 10a Long hole 11 First DESCRIPTION OF SYMBOLS 1 Support frame 11a Long hole 12 2nd support frame 12a Hole 13 Square frame 13a Hole 14 Connection string 14a Hook 15 Connection rod 16 Support rod 17 Ring rod 18 Pulley 19 Worker 20, 21 Ring frame 30, 31, 32 Steel tower 30a, 31a, 32a Post 30b Scaffolding bolt 33 Vertical net 34 Steel tower structure 35 Beam 36 Transfer rod 36a Partition space 37 Rope 38 Tie string 39 Rope 40 Steel tower 41 Vertical rope 42 Lifting adjustment fitting 43 Annular frame 44 Protective net 45 Hook fitting 50 First Non-slip 50a hole 51 second sliding studs 51a holes 61, 62, 63, 64 connected string A vertical ladder P steel column R ropes

Claims (4)

Attach a protective net with an opening through which the tower penetrates in the center to a frame that is larger than the outer periphery of the steel tower with a polygonal cross section with multiple pillars, and attach the frame with this protective net every time a tower is assembled. covered from tower top, one end of the frame to the tower winding the posts, suspended and fixed by the connecting member is a rope connecting the other end to the frame, and stretched the internal net inside tower, protecting the internal network A method for attaching a protective net to a steel tower, wherein the protective net is stretched around the steel tower by closing the opening of the protective net by binding the net. Along with the protective net, a vertical net that covers the outer periphery of the tower is attached to a frame with a protective net excluding the frame with the lowermost protective net. 2. The method for attaching a protective net to a steel tower according to claim 1, wherein the frame is attached to a frame with a lower protective net, and a frame between the upper and lower protective nets is covered with a vertical net. The frame is constituted by a plurality of tubular members, and another tubular member is inserted into one tubular member, or one tubular member and another tubular member are partially overlapped to each other so as to be detachable from each other. The method for attaching a protective net to a steel tower according to claim 1 , wherein the protective net is configured to be stretchable by being fixed with a bracket. The rope is provided with a hook at one end, and the other end of the rope is wound around the frame and fixed so as to be sewed to the first anti-slip fitting. One end of the rope with the hook is The steel tower according to any one of claims 1 to 3 , wherein the steel tower is wound around the pillar through a scaffolding bolt provided in the steel tower pillar, and is fixed by hooking the hook on a second anti-slip metal fitting through which the rope penetrates. How to attach the protective net to the

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