JP2021067031A - Pipe for scaffold and scaffold using the same - Google Patents

Abstract

To provide a pipe for a scaffold capable of increasing bending strength without increasing an outer diameter size and reducing an increase in weight, and the scaffold using the same.SOLUTION: A scaffolding pipe 20 is composed of an outer pipe 21 formed in a predetermined L1 and an inner pipe 22 arranged in the outer pipe 21, and the inner pipe 22 is formed in a L1 shorter than the L2 of the outer pipe 21; since the inner pipe 22 is arranged on the center side in the longitudinal direction of the outer pipe 21 and a partial part 20a where the inner pipe 22 does not exist is provided on both end sides in the longitudinal direction of the outer pipe 21, a double pipe structure comprising the outer pipe 21 and the inner pipe 22 can be formed. As a result, the cross-sectional secondary moment can be increased by the outer pipe 21 and the inner pipe 22 compared with a normal single pipe, and the bending strength can be increased.SELECTED DRAWING: Figure 3

Description

The present invention relates to, for example, a scaffolding pipe used as a constituent member of a suspended scaffolding for a bridge, and a scaffolding using the pipe.

Conventionally, when erection of steel girders and construction of floor slabs on bridges such as general roads and highways, work scaffolding is installed directly under the steel girders for construction work. In addition, even if the steel girder is deteriorated and damaged in the existing steel bridge, a work scaffolding will be installed directly under the steel girder to repair, reinforce, and process the damaged part. In addition, when the floor slab becomes old, the existing floor slab is removed from the main girder and a new floor slab is erected. In that case, the same applies to the bridge body. Scaffolding for work is installed. In these cases, there are many cases where there are roadways in service below and near the bottom of the construction site, and it is not possible to assemble the scaffolding from the ground. Therefore, in such a bridge, a suspended scaffold suspended from a bridge girder or the like is used (see, for example, Patent Document 1).

The conventional suspension scaffold has a floor surface portion in which a large number of pipes (oyago) extending in the direction of the bridge axis and a large number of pipes (rolling) extending in the direction perpendicular to the bridge axis are connected by a connecting metal fitting (clamp) and the direction of the bridge axis. A large number of pipes (Mr. Naka) extending to the bridge and a large number of pipes (building site) extending in the direction perpendicular to the bridge axis are connected with a connecting metal fitting (clamp) to provide a side surface (morning glory), which is provided by a large number of hanging chains. It is installed by hanging from the bridge body.

Utility Model Registration No. 3120301

By the way, a commercially available standard steel pipe is used for the pipe of the suspension scaffold, and a steel pipe having an outer diameter of 48.6 mm is a standard standard product. However, with standard pipes, the bending strength may not be sufficient in some cases, such as when the assembled shape or an excessive wind load due to a typhoon or gust must be a design condition. In that case, bending strength can be increased by using a pipe with high strength and a large outer diameter, but the weight of the pipe increases as the outer diameter increases, which imposes a burden on the operator when assembling and disassembling the scaffold. There is a problem of increasing. Further, if only the pipe used for the portion where the bending strength is not sufficient (for example, the side portion affected by the wind pressure) has a large outer diameter, the increase in the burden on the operator can be reduced, but the outer diameter is different. When pipes are mixed, a plurality of types of other parts such as connecting metal fittings are required depending on the size of the pipes, and there is also a problem that the management and assembly work of the members becomes complicated.

The present invention has been made in view of the above problems, and an object of the present invention is for a scaffold that can increase bending strength without increasing the outer diameter size and can reduce the increase in weight. The purpose is to provide a pipe and a scaffold using the pipe.

The present invention includes an outer pipe formed to a predetermined length and an inner pipe arranged in the outer pipe in a scaffold pipe used as a component of the scaffold in order to achieve the above object. Is formed to have a length shorter than the length of the outer pipe, and the inner pipe is arranged on the center side in the length direction of the outer pipe to provide portions on both ends in the length direction of the outer pipe where the inner pipe does not exist.

As a result, since the outer pipe and the inner pipe form a double pipe structure, the geometrical moment of inertia of the outer pipe and the inner pipe is larger than that of the normal single pipe, and the bending strength is increased. In this case, by arranging the inner pipe inside the outer pipe having the same outer diameter as the normal single pipe, the bending strength is increased without increasing the outer diameter size as compared with the normal single pipe. Further, since the inner pipe is formed shorter than the outer pipe and is arranged on the center side in the length direction of the outer pipe, the bending resistance force near the center of the pipe is increased, so that the maximum bending stress of the outer pipe is increased. The center of the outer pipe in the length direction and its vicinity are reinforced, and both ends of the outer pipe in the length direction where the bending stress is small are the parts where the inner pipe does not exist. It is possible to reduce the increase in weight due to the inner pipe while ensuring the strength of the pipe.

According to the present invention, the bending strength can be increased by the outer pipe and the inner pipe as compared with a normal single pipe, so that when used as a component of a suspended scaffold, for example, a typhoon or a typhoon which is dominant as a design load of the scaffold It is possible to increase the strength of the portion constituting the portion where an excessive wind load such as a gust of wind acts. In this case, since the bending strength can be increased without increasing the outer diameter size as compared with the normal single pipe, it is possible to use the same connecting metal fittings as the normal single pipe, and different diameter pipes are mixed. There is an advantage that the management of members and the assembly work are not complicated. Further, since it is possible to reduce the increase in weight due to the inner pipe while ensuring high strength against bending, there is an advantage that the burden on the operator at the time of assembling and disassembling the scaffolding is not significantly increased.

Front view of a suspended scaffold showing the first embodiment of the present invention Partial perspective view of the suspended scaffolding Side view of scaffolding pipe Cross-sectional view of the scaffolding pipe in the direction of the XX arrow Disassembled side view of scaffolding pipe Disassembled side sectional view of scaffolding pipe Side sectional view of scaffolding pipe An exploded side sectional view of a scaffolding pipe showing a modified example of the first embodiment. Side sectional view of scaffolding pipe An exploded side sectional view of a scaffolding pipe showing a second embodiment of the present invention. Side sectional view of scaffolding pipe An exploded side sectional view of a scaffolding pipe showing a third embodiment of the present invention. Side sectional view of scaffolding pipe

1 to 9 show the first embodiment of the present invention, and show a scaffolding pipe used as a constituent member of a suspended scaffolding for a bridge.

In the bridge shown in the figure, a plurality of main girders 1 arranged at intervals in the width direction are supported by piers 2, and a floor slab 3 is installed on each main girder 1. Further, below the bridge body, a suspension scaffold 10 suspended from the main girder 1 is installed.

As shown in FIG. 2, the suspended scaffolding 10 has a floor surface portion 11 arranged below the bridge body and a side surface portion 12 (morning glory) extending diagonally upward from both ends of the floor surface portion 11 in the direction perpendicular to the bridge axis. It consists of. The floor surface portion 11 and the side surface portion 12 are suspended from the bridge main body side by a large number of suspension chains 13 and are covered with a protective net 14. Further, a scaffolding plate 15 is placed on the floor surface portion 11. Although not shown, it is often the case that a protective worker with a wooden board (plywood) or the like attached to the inside of the suspended scaffolding is also installed for the purpose of protecting the roadway below.

The floor surface portion 11 is formed by connecting a plurality of first pipes 11a (oyago) extending in the direction of the bridge axis and a plurality of second pipes 11b (rolling) extending in the direction perpendicular to the bridge axis by connecting metal fittings (not shown). It is formed.

The side surface portion 12 includes a plurality of third pipes 12a (middle) extending in the direction of the bridge axis, and a plurality of fourth pipes 12b (building sites) extending diagonally upward along a direction orthogonal to the third pipe 12a. Is formed by connecting with a connecting metal fitting (not shown). Further, the side surface portion 12 is connected to the floor surface portion 11 by a plurality of fifth pipes 12c (not done) extending diagonally.

Next, the scaffolding pipe of the present embodiment will be described with reference to FIGS. 3 to 7. Since the scaffolding pipe of the present embodiment is formed so as to have a higher bending strength than a normal single pipe (single pipe) as described later, a third side portion 12 that is susceptible to wind load is formed. Used for the pipe 12a, the fourth pipe 12b, and the fifth pipe 12c. A normal single pipe is used for the first pipe 11a and the second pipe 11b constituting the floor surface portion 11.

As shown in FIG. 3, the scaffolding pipe 20 of the present embodiment includes an outer pipe 21 formed to a predetermined length L1 and an inner pipe 22 arranged in the outer pipe 21, and the inner pipe 22 is provided. It is formed to have a predetermined length L2 shorter than the length L1 of the outer pipe 21. In this case, the inner pipe 22 is formed so that its length L2 is 10% or more and 80% or less of the length L1 of the outer pipe.

The outer pipe 21 is made of, for example, a steel pipe having an outer diameter Dx1 of 48.6 mm and an inner diameter Dy1 of 43.8 mm, and is equivalent to a normal single pipe used for the first pipe 11a and the second pipe 11b. ..

The inner pipe 22 is made of, for example, a steel pipe having an outer diameter Dx2 of 42.7 mm and an inner diameter Dy2 of 38.1 mm, and is formed to have an outer diameter slightly smaller than the inner diameter of the outer pipe 21.

As shown in FIG. 5, the inner pipe 22 is inserted into the outer pipe 21 from one end side in the length direction of the outer pipe 21 and is arranged on the center side in the length direction of the outer pipe 21. As a result, as shown in FIG. 3, single portions 20a in which the inner pipe 22 does not exist are provided on both ends of the outer pipe 21 in the length direction in the scaffolding pipe 20. Further, as shown in FIGS. 6 and 7, the inner pipe 22 is fixed in the outer pipe 21 by a pair of fixing pins 23. That is, pin insertion holes 21a and 22a penetrating the outer and inner pipes 21 and 22 are provided at two locations in the length direction of the outer pipe 21 and the inner pipe 22 at equal intervals, and the pin insertion holes 21a and 22a are provided in the respective pin insertion holes 21a and 22a. By inserting and fixing each fixing pin 23, each fixing pin 23 restricts the movement of the inner pipe 22 with respect to the outer pipe 21 in the length direction. That is, each fixing pin 23 forms an insertion member as a movement restricting means.

The scaffolding pipe 20 of the present embodiment includes an outer pipe 21 formed to have a predetermined length L1 and an inner pipe 22 arranged in the outer pipe 21, and the inner pipe 22 has a length L1 of the outer pipe 21. It is formed to have a predetermined length L2 shorter than that, and the inner pipe 22 is arranged on the center side in the length direction of the outer pipe 21 to provide portions 20a in which the inner pipe 22 does not exist on both ends in the length direction of the outer pipe 21. Therefore, a double pipe structure including the outer pipe 21 and the inner pipe 22 can be formed. That is, as compared with a normal single pipe, the moment of inertia of area can be increased by the outer pipe 21 and the inner pipe 22, and the bending strength can be increased. As a result, when used as a constituent member of the suspended scaffold 10, the strength against an excessive wind load such as a typhoon or a gust can be increased.

In this case, since the inner pipe 22 is arranged inside the outer pipe 21 having an outer diameter equivalent to that of the normal single pipe, the bending strength is increased without increasing the outer diameter size as compared with the normal single pipe. be able to. As a result, the scaffolding pipe 20 can use a connecting metal fitting or the like common to a normal single pipe, and has an advantage that member management and assembly work are not complicated due to a mixture of pipes having different diameters. ..

Further, since the inner pipe 22 is formed shorter than the outer pipe 21 and is arranged on the center side in the length direction of the outer pipe 21, the length direction of the outer pipe 21 where the maximum bending stress of the outer pipe 21 is generated. Since the center and its vicinity can be reinforced and both ends of the outer pipe 21 in the length direction where the bending stress is small are single portions 20a in which the inner pipe 22 does not exist, the strength against the generated bending cross-sectional force can be increased. It is possible to minimize the increase in weight due to the inner pipe 22 while ensuring it, and there is an advantage that the burden on the operator at the time of assembling and disassembling the scaffolding is not significantly increased.

In this case, since the inner pipe 22 is formed to have a length L2 of 10% or more and 80% or less of the length L1 of the outer pipe 21, the length of the inner pipe 22 is not insufficient and the reinforcing effect is not insufficient. There is an advantage that the inner pipe 22 is not too long and the weight is not unnecessarily increased.

Further, since the movement of the inner pipe 22 with respect to the outer pipe 21 in the length direction is restricted by the contact with each fixing pin 23, the position of the inner pipe 22 is surely held on the center side of the outer pipe 21. be able to.

Further, the fixing pins 23 inserted into the pin insertion holes 21a and 22a penetrating the outer and inner pipes 21 and 22 restrict the movement of the inner pipe 21 with respect to the outer pipe 22 in the length direction. The inner pipe 22 does not move carelessly inside the pipe 21, and the inner pipe 22 can be reliably held in the center of the outer pipe 21 in the length direction.

Further, when the scaffolding pipe 20 of the present embodiment is used for the suspended scaffolding 10, the third pipe 12a, the fourth pipe 12b and the fifth pipe 12a of the side surface portion 12 which is more susceptible to wind load than the floor surface portion 11 of the suspended scaffolding 10 By using a normal single pipe for the first pipe 11a and the second pipe 11b of the floor surface portion 11, the scaffolding of the present embodiment is used only for the side surface portion 12 whose strength needs to be increased. If the pipe 20 is used, the increase in the weight of the entire scaffold can be minimized.

Further, as shown in FIGS. 8 and 9, by attaching cap-shaped sealing members 24 to both ends of the outer pipe 21 in the length direction, both ends of the outer pipe 21 can be sealed by each sealing member 24. , Water and foreign matter can be reliably prevented from entering the outer pipe 21.

10 and 11 show a second embodiment of the present invention, and the same components as those of the first embodiment are designated by the same reference numerals.

In the present embodiment, instead of the fixing pin 23 of the first embodiment, a pair of spacers 25 are used as a contact members of the movement restricting means.

Each spacer 25 is made of a lightweight and inexpensive cylindrical member such as a vinyl chloride pipe having an outer diameter equivalent to the inner diameter of the outer pipe 21, and is arranged in each single portion 20a in the outer pipe 21. There is.

That is, in the present embodiment, as shown in FIG. 10, each spacer 25 is inserted into each single portion 20a in the outer pipe 21, and both ends of the outer pipe 21 are sealed by each sealing member 24. The spacer 25 is held between the end of the inner pipe 22 and each sealing member 24. In this case, the spacer 25 is formed to have a length shorter than the length of the insertion portion of the sealing member 24. As a result, both ends of the inner pipe 22 come into contact with each spacer 25, and the movement of the inner pipe 22 with respect to the outer pipe 21 in the length direction is restricted.

According to the present embodiment, by inserting each spacer 25 into the outer pipe 21 and sealing both ends of the outer pipe 21 with each sealing member 24, the scaffolding pipe 20 in which the movement of the inner pipe 22 is restricted can be easily achieved. Can be manufactured in.

In the above embodiment, the spacer 25 made of a cylindrical member such as a vinyl chloride pipe is used, but a spacer made of a cylindrical synthetic resin molded product or the like may be used.

12 and 13 show a third embodiment of the present invention, and the same components as those of the first embodiment are designated by the same reference numerals.

In the present embodiment, the filler 26 is used as the movement restricting means instead of the fixing pin 23 and the sealing member 24 of the first embodiment.

The filler 26 is made of a foaming material such as urethane foam, and each single portion 20a in the outer pipe 21 is filled with the filler 26.

That is, in the present embodiment, as shown in FIG. 12, the filler 26 is injected into each single portion 20a in the outer pipe 21 via the nozzle A, foamed, and cured, so that the filler 26 is inside by the cured filler 26. The pipe 22 is held in the outer pipe 21. In this case, although not shown, both ends of the inner pipe 22 are closed in advance so that the filler 26 injected into the outer pipe 21 does not enter the inner pipe 22. Since the cured filler 26 is fixed to the inner surface of the outer pipe 21, each filler 26 restricts the movement of the inner pipe 22 with respect to the outer pipe 21 in the length direction.

Further, since the inside of each single portion 20a of the outer pipe 21 is sealed by the cured filler 26, it is possible to reliably prevent water and foreign matter from entering the outer pipe 21 by each filler 26.

In the above embodiment, the scaffolding pipe 20 is used for the third pipe 12a, the fourth pipe 12b, and the fifth pipe 12c of the side surface portion 12 of the suspended scaffolding 10, but the scaffolding pipe 20 is used for the scaffolding. The pipe using the pipe 20 is not limited to these. Further, the scaffolding pipe 20 may be used for all the pipes of the suspension scaffolding 10. Further, the scaffolding pipe 20 can be used for a portion other than the portion constituting the suspended scaffolding itself (for example, a member supporting a crossover passage).

Further, in the above embodiment, the scaffolding pipe 20 is used for the suspension scaffolding 10, but the scaffolding pipe of the present invention is not limited to the suspension scaffolding, and the scaffolding installed on the ground or the like is not limited to the suspension scaffolding. , Can also be used for other scaffolding.

It should be noted that the embodiment is an embodiment of the present invention, and the present invention is not limited to those described in the respective embodiments.

1 ... Main girder, 10 ... Suspended scaffolding, 20 ... Scaffolding pipe, 20a ... Single part, 21 ... Outer pipe, 22 ... Inner pipe, 23 ... Fixing pin, 24 ... Sealing member, 25 ... Spacer, 26 ... Filler.

Claims (8)

In scaffolding pipes used as scaffolding components
An outer pipe formed to a predetermined length and
With an inner pipe located inside the outer pipe,
Form the inner pipe to a length shorter than the length of the outer pipe, and
A scaffolding pipe characterized in that the inner pipe is arranged on the center side in the length direction of the outer pipe and the portions where the inner pipe does not exist are provided on both ends in the length direction of the outer pipe. The scaffolding pipe according to claim 1, wherein the inner pipe is formed to have a length of 10% or more and 80% or less of the length of the outer pipe. The scaffolding pipe according to claim 1 or 2, further comprising a movement restricting means for restricting the movement of the inner pipe with respect to the outer pipe in the length direction. The scaffolding pipe according to claim 3, wherein the movement restricting means comprises an insertion member inserted into a hole penetrating the outer pipe and the inner pipe in the radial direction. The scaffolding pipe according to claim 3, wherein the movement restricting means is composed of abutting members that come into contact with both ends of the inner pipe in the length direction. The scaffolding pipe according to claim 3, wherein the movement restricting means is made of a filler filled on both ends of the outer pipe. The scaffolding pipe according to claim 1, 2, 3, 4 or 5, further comprising a sealing member that seals both ends of the outer pipe in the length direction. A scaffolding characterized in that the scaffolding pipe according to claim 1, 2, 3, 4, 5, 6 or 7 is used for the pipe as at least a part of the scaffolding constituent members.

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