JP2019007337A - Installation structure for tubular structure, and tubular structure - Google Patents

Abstract

To provide a tubular structure using a taper tube, which prevents stress concentration and which reduces an influence exerted on a member by environmental conditions.SOLUTION: An installation structure 1 for a tubular structure comprises a taper tube 2 that has a taper shape throughout its length, and a base 3 that includes a body part 4 and a tubular protrusion 5 protruding from the body part 4 and pressed into the side of an inner peripheral surface 2a of the taper tube 2. An outer peripheral surface 51 of the tubular protrusion 5 has a taper shape corresponding to an inner peripheral surface 2a of the taper tube 2. An outside diameter of the tubular protrusion 5 varies from a first outside diameter Dlarger than an inside diameter dof an end opening of the taper tube 2 by the taper shape of the outer peripheral surface 51 to a second outside diameter Dsmaller than the inside diameter dof the end opening.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a pipe structure mounting structure and a pipe structure, and more particularly to a pipe structure mounting structure and a pipe structure using a tapered pipe.

  For example, a tapered steel pipe used for a column for installing lighting or a sign on a road or a park is known. The tapered steel pipe is a steel pipe having a taper shape extending over almost the entire length, that is, a shape gradually tapering toward one end side in the length direction, and is manufactured, for example, by spinning as described in Patent Document 1. Here, as described in, for example, FIG. 4 of Patent Document 2, in the conventional basic structure of such a tapered steel pipe, the lower end of the tapered steel pipe is welded to the base plate, and the upper surface of the base plate and the lower side surface of the tapered steel pipe The vertical ribs for reinforcement were welded to.

  On the other hand, in FIG. 1 and the like of Patent Document 2, a structure is proposed in which longitudinal ribs are welded to an exterior support pipe attached to the lower part of the tapered steel pipe, and the exterior support pipe and the tapered steel pipe are friction bonded. Yes. In this case, since the tapered steel pipe and the vertical rib are not directly welded, stress concentration on the welded portion in the conventional foundation structure can be prevented. In addition, in FIG. 5 etc. of patent document 2, the structure which forms an exterior support pipe and a base plate continuously with cast steel, and fixes between an exterior support pipe and a taper steel pipe with a wedge is also proposed.

Japanese Patent Laid-Open No. 10-24323 JP 2003-49561 A

  However, in the case of the foundation structure described in Patent Document 2, since the exterior support pipe is attached to the outside of the tapered steel pipe, the upper end of the exterior support pipe has a structure in which rainwater tends to accumulate at the joint with the tapered steel pipe. As described above, since tapered steel pipes are often used for outdoor facilities, the structure of such a joint is disadvantageous in that it is easily affected by environmental conditions such as rainwater.

  Accordingly, the present invention provides a new and improved pipe structure mounting structure and pipe structure capable of preventing stress concentration and reducing the influence of environmental conditions in a pipe structure using a tapered pipe. The purpose is to provide.

An attachment structure for a pipe structure according to an aspect of the present invention includes a taper pipe having a tapered shape over its entire length, a main body part, and a tubular projecting part that projects from the main body part and is press-fitted into the inner peripheral surface side of the tapered pipe. With. The outer peripheral surface of the tubular protrusion has a taper shape corresponding to the inner peripheral surface of the tapered tube, and the outer diameter of the tubular protrusion is larger than the inner diameter of the end opening of the tapered tube due to the tapered shape of the outer peripheral surface. The diameter changes from the diameter to a second outer diameter that is smaller than the inner diameter of the end opening.
By press-fitting the tubular projecting portion having the above shape to the inner peripheral surface side of the tapered tube, the pedestal and the tapered tube can be securely supported and joined together. In support pressure bonding, no welded portion is formed between the tapered tube and another member, so stress concentration on the welded portion does not occur. Moreover, the junction part of a taper pipe and a tubular protrusion part is a structure where rain water does not accumulate easily.

In the above mounting structure, the main body portion and the tubular projecting portion of the pedestal may be formed continuously.
For example, when the main body portion of the pedestal and the tubular projecting portion are continuously formed by casting or the like, since no welded portion is formed between each portion of the pedestal, stress concentration on the welded portion does not occur.

In the mounting structure described above, the wall thickness of the tubular projecting portion may become thinner toward the end opposite to the main body portion.
By changing the thickness of the tubular projecting portion as described above, the weight of the pedestal can be reduced while reducing the stress acting on the connection portion between the tubular projecting portion and the main body portion.

The attachment structure may further include an electrical component attached to the inner peripheral surface of the tubular protrusion.
By attaching electrical components to the inner peripheral surface of the tubular protrusion before joining the tapered steel pipe and the pedestal, there is no need to form an opening in the peripheral surface of the tapered tube, and stress concentration in the opening is prevented. be able to.

In the mounting structure described above, the tubular projecting portion may include a beveled surface formed following the outer peripheral surface at the end opposite to the main body portion. Further, in this case, the tubular protrusion may have a groove connected to the oblique surface and extending in the longitudinal direction of the tubular protrusion along the outer peripheral surface.
As a result, the beveled surface tends to guide the water droplets that have traveled along the inner peripheral surface of the tapered tube to the outer peripheral surface side of the tubular projecting portion, thereby preventing the inflow to the inner peripheral surface side as much as possible. Can do. Further, when the groove is provided, the water droplets accumulated on the oblique surface can be discharged to the outside of the tapered tube, so that the influence of the water droplets on the pedestal and the electric parts can be reduced.

In the above mounting structure, the main body may be a base plate.
The base plate is attached to the foundation or the ground, for example. In this case, the attachment structure functions as the basic structure of the pipe structure.

In the above mounting structure, the pedestal may be divided into a plurality of portions.
By dividing the pedestal into a plurality of parts, the size of each part is reduced, and the manufacture and transportation of the pedestal are facilitated.

  According to another viewpoint of this invention, the pipe structure containing said attachment structure is provided.

  As described above, according to the present invention, stress concentration can be prevented and the influence of environmental conditions can be reduced in a pipe structure using a tapered pipe.

It is a longitudinal section of the basic structure concerning a 1st embodiment of the present invention. It is a longitudinal cross-sectional view of the basic structure which concerns on the 2nd Embodiment of this invention. It is sectional drawing in the III-III line of the basic structure shown by FIG. It is a figure which shows the example of the steel pipe structure which concerns on the 3rd Embodiment of this invention. It is a longitudinal section showing the 1st example in which a base is divided into a plurality of parts in an embodiment of the present invention. It is a cross-sectional view which shows the 1st example by which a base is divided | segmented into a several part in embodiment of this invention. It is a figure which shows the modification of the example shown by FIG. 5A and 5B. It is a figure which shows another modification of the example shown by FIG. 5A and 5B. It is a figure which shows another modification of the example shown by FIG. 5A and 5B. It is a longitudinal cross-sectional view which shows the 2nd example by which a base is divided | segmented into a some part in embodiment of this invention. It is a figure which shows the modification of the example shown by FIG. It is a figure which shows the modification of the example shown by FIG. It is a figure which shows the state which two parts shown by FIG. 8A were mutually engaged. It is a figure which shows another modification of the example shown by FIG.

  Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the present specification and drawings, components having substantially the same functional configuration are denoted by the same reference numerals, and redundant description is omitted.

(First embodiment)
FIG. 1 is a longitudinal sectional view of a foundation structure according to the first embodiment of the present invention. A basic structure 1 shown in FIG. 1 is constituted by a tapered steel pipe 2 and a pedestal 3. The tapered steel pipe 2 has a uniform tapered shape over its entire length. Specifically, in the present embodiment, the tapered steel pipe 2 has a shape that gradually decreases in diameter as it goes to one end side in the length direction (the upper end side in FIG. 1). Note that the thickness of the tapered steel pipe 2 is substantially constant over the entire length. The angle θ ₁ formed by the tube wall of the tapered steel pipe 2 with respect to the longitudinal axis is hereinafter also referred to as the taper angle of the tapered steel pipe 2. On the other hand, the pedestal 3 includes a base plate 4 that is a main body portion and a tubular projecting portion 5 that projects from the base plate 4. As shown in the drawing, the tubular projecting portion 5 is press-fitted into the tapered steel pipe 2, and the tapered steel pipe is caused by the supporting pressure and the frictional force acting between the outer peripheral surface 51 of the tubular projecting portion 5 and the inner peripheral surface 2 a of the tapered steel pipe 2. 2 and the base 3 are joined.

  Here, in this embodiment, the pedestal 3 is continuously formed using cast steel, cast iron, or the like, and the base plate 4 and the tubular protruding portion 5 are continuous via a rounded connecting portion 6. Here, in the present specification, “continuous” does not simply mean that the shapes of the plurality of portions are continuous, but also means that the material composition of the plurality of portions is continuous. For example, when the base 3 including the base plate 4 and the tubular protrusion 5 is formed by casting, the material composition of the base plate 4 and the tubular protrusion 5 is continuous. By continuously forming the pedestal 3 in this way, for example, a discontinuous portion of the material composition due to welding or the like is not formed between the base plate 4 and the tubular protruding portion 5, and stress concentration in the pedestal 3 is prevented. be able to. In the case of casting, since the overall material composition is substantially uniform, stress concentration is unlikely to occur in the entire pedestal 3. In casting, since the degree of freedom of the shape of the manufactured part is high, for example, the shape of the inner peripheral surface 52 of the tubular projecting portion 5 as described later can be freely designed while ensuring the integrity.

In order to enable joining by the bearing pressure and frictional force between the tapered steel pipe 2 and the pedestal 3 as described above, the outer peripheral surface 51 of the tubular projecting portion 5 has a tapered shape corresponding to the tapered steel pipe 2, that is, tubular. The protruding portion 5 has a shape that gradually tapers as it goes to the end opposite to the base plate 4 (upper end in FIG. 1). The angle θ ₂ formed by the outer peripheral surface 51 with respect to the longitudinal axis of the tubular protrusion 5 (axis perpendicular to the base plate 4) is also referred to as a taper angle of the outer peripheral surface 51 below. In the present embodiment, the taper angle θ ₂ of the outer peripheral surface 51 is substantially equal to the taper angle θ ₁ of the tapered steel pipe 2 or slightly smaller than the taper angle θ ₁ .

The outer diameter of the tubular projection 5, the tapered shape of the outer circumferential surface 51 as described above, the first outer diameter D ₁ at the lower end of the tubular projection 5 (a boundary between the connecting part 6), the tubular projection 5 changes to a second outer diameter D ₂ at the upper end. The first outer diameter D ₁ is larger than the inner diameter d ₁ of the end opening of the tapered steel pipe 2, the second outer diameter D ₂ is smaller than the inner diameter d ₁ of the end opening. Due to such a structure, when the tubular protrusion 5 is press-fitted from the end opening of the tapered steel pipe 2 to an appropriate depth, either the tapered steel pipe 2 or the tubular protrusion 5 or both are elastically deformed. By utilizing the restoring force of the elastic deformation, the transmission of force between the inner peripheral surface 2a of the tapered steel pipe 2 and the outer peripheral surface 51 of the tubular projecting portion 5 can be made efficient.

On the other hand, unlike the outer peripheral surface 51, the inner peripheral surface 52 of the tubular projecting portion 5 does not have a tapered shape. In the illustrated example, the inner peripheral surface 52 of the tubular protrusion 5 has a straight shape. In other words, the inner diameter d ₂ of the tubular projection 5 is constant from the lower end of the tubular projection 5 (a boundary between the connecting part 6) to the upper end. As a result, the wall thickness at the upper end (the end opposite to the base plate 4) of the tubular protrusion 5 is thinner than the wall thickness at the lower end (the end on the base plate 4 side). As a result, the tubular protrusion 5 gradually becomes thinner as it goes from the lower end to the upper end as a whole. In this way, the weight of the base 3 can be reduced while reducing the stress applied to the lower end of the tubular protrusion 5. Further, in the example shown, by the inner diameter d ₂ of the tubular projection 5 is constant from the lower end to the upper end, there is no recessed portion when viewed from the opening at the upper end inside of the tubular projection 5, the base 3 by casting Is easy to manufacture.

  In order to obtain the same effect as described above, the inner peripheral surface 52 of the tubular projecting portion 5 has a tapered shape opposite to the tapered shape of the outer peripheral surface 51 (that is, a funnel shape opened upward in the figure). You may have. Alternatively, when the inner peripheral surface 52 does not have a tapered shape, the inner diameter of the tubular protruding portion 5 is not constant from the lower end to the upper end, and the inner diameter at the upper end becomes larger than the inner diameter at the lower end due to a step formed in the middle. It may be. Even in such a case, the thickness at the upper end of the tubular protrusion 5 is thinner than the thickness at the lower end.

  In addition, in the basic structure 1, the electrical component 7 is attached to the inner peripheral surface 52 of the tubular projecting portion 5. For example, when the tapered steel pipe 2 is used as a support for installing lighting, signs, etc., it is necessary to attach an electrical component 7 connected to a device such as a lighting device installed in the upper part to the foundation structure 1. For example, in the case of a foundation structure in which an exterior support pipe is attached to the outside of a tapered steel pipe (that is, the tapered steel pipe is inserted inside the exterior support pipe), electrical components cannot be attached to the inside of the exterior support pipe. Electrical components are installed inside the steel pipe. In this case, since it is difficult to insert and attach the electrical component from the end opening of the tapered steel pipe, an opening for attaching the electrical component is formed on the peripheral surface of the tapered steel pipe. However, since stress concentration is likely to occur in the opening, it is desirable to reduce the opening as much as possible. In the basic structure 1 according to the present embodiment, since the tapered steel pipe 2 is located outside the tubular projecting portion 5, an electrical component is attached to the inner peripheral surface 52 of the tubular projecting portion 5 before joining the tapered steel pipe 2 and the pedestal 3. 7 can be attached, and the opening formed in the tapered steel pipe 2 for attaching the electrical component 7 can be reduced.

  According to the first embodiment of the present invention as described above, in the basic structure 1, the tapered steel pipe 2 and the pedestal 3 can be securely supported and joined. In the support joint, since no weld is formed between the tapered steel pipe 2 and another member, stress concentration on the weld does not occur. Moreover, according to this embodiment, in the junction part of the taper steel pipe 2 and the tubular protrusion part 5, the edge part of the outer side of the boundary part of the inner peripheral surface of the taper steel pipe 2 and the outer peripheral surface of the tubular protrusion part 5 is provided. Is directed in a direction (downward) where rainwater does not collect easily, so that the influence of environmental conditions such as rainwater can be reduced.

  Moreover, according to this embodiment, since the base plate 4 and the tubular projecting portion 5 of the pedestal 3 are continuously formed using cast steel, no weld is formed between the portions of the pedestal 3, and accordingly. No stress concentration on the weld. Furthermore, according to the present embodiment, the weight of the pedestal 3 is reduced while reducing the stress applied to the lower end of the tubular protrusion 5 by reducing the thickness of the tubular protrusion 5 of the pedestal 3 toward the upper end. Can be reduced. Moreover, in this embodiment, an electrical component can be attached to the inner peripheral surface 52 of the tubular projecting portion 5 to reduce the number of openings formed in the tapered steel pipe 2.

(Second Embodiment)
FIG. 2 is a longitudinal sectional view of the foundation structure according to the second embodiment of the present invention. 3 is a cross-sectional view taken along line III-III of the basic structure shown in FIG. As a difference from the first embodiment described above, in the basic structure 11 shown in FIGS. 2 and 3, the upper end of the tubular protrusion 5 (the end opposite to the base plate 4) continues to the outer peripheral surface 51. Thus, the oblique surface 53 is formed. Further, in the foundation structure 11, a groove 54 extending in the longitudinal direction of the tubular protruding portion 5 is formed along the outer peripheral surface 51. As shown in FIG. 2, the groove 54 is connected to the beveled surface 53 and extends to the vicinity of the lower end of the tubular protrusion 5 that is not covered by the tapered steel pipe 2. As shown in FIG. 3, four grooves 54 arranged at equal intervals in the circumferential direction are formed on the outer peripheral surface 51 of the tubular projecting portion 5. Note that the number of the grooves 54 illustrated is an example, and a larger or smaller number of grooves 54 may be formed in other examples. Further, the interval between the grooves 54 in the circumferential direction is not necessarily equal. Further, the groove 54 is not necessarily provided. In addition to the above, the configuration of the foundation structure 11 according to this embodiment is the same as that of the foundation structure 1 according to the first embodiment.

The beveled surface 53 has a tapered shape with a taper angle θ ₃ larger than the taper angle θ ₂ of the outer peripheral surface 51, thereby forming a bevel at the upper end portion of the tubular projecting portion 5. By forming such an oblique angle, for example, water droplets originating from rainwater and the like and having been transmitted from the upper part of the tapered steel pipe 2 to the inner peripheral surface 2a are guided to the outer peripheral surface 51 side of the tubular projecting portion 5, and further the groove 54 And is discharged to the outside of the tapered steel pipe 2 or the tubular protrusion 5. As a result, it is possible to prevent water droplets from accumulating inside the tubular protrusion 5 and the electrical component 7 from being affected by the water droplets.

(Third embodiment)
FIG. 4 is a diagram showing an example of a steel pipe structure according to the third embodiment of the present invention. In the illuminating lamp 30 shown in FIG. 4, the tapered steel pipe 2 is used as a support column. The illuminating lamp 30 includes a tapered steel pipe 2 and a pedestal 3 that constitute the same basic structure 1 as in the first embodiment described above, an arm 31 attached to the upper portion of the tapered steel pipe 2, and an illuminating device attached to the tip of the arm 31. 32. In addition, the structure of such an illumination lamp 30 is an example, and various other structures are possible. For example, the lighting device 32 may be directly attached to the upper part of the tapered steel pipe 2 without providing the arm 31. Moreover, a curved pipe may be connected to the upper end of the taper steel pipe 2, and the illuminating device 32 may be attached to the front-end | tip.

  In the illuminating lamp 30 as described above, the tapered steel pipe 2 is used as a support column, thereby reducing the stress concentration at the support column base portion and effectively preventing fatigue damage. Specifically, the weight of the tapered steel pipe 2 is reduced by reducing the diameter of the tapered steel pipe 2 at the top. Moreover, the wind load which the wind of the sky gives to the taper steel pipe 2 is also reduced by the pipe diameter of the taper steel pipe 2 being small in the upper part. On the other hand, by reducing the diameter of the tapered steel pipe 2 at the lower part, the stress applied to the lower end of the tapered steel pipe 2 due to the wind load, the vibration load due to vehicle running, the earthquake load, etc. is reduced. Can do.

  In addition, the example of the steel pipe structure which concerns on embodiment of this invention is not restricted to the illuminating lamp which concerns on said 3rd Embodiment, For example, various steel pipe structures for which a tapered steel pipe has been used conventionally, such as a sign including. In the steel pipe structure, the tapered steel pipe is not necessarily used as a column, and may be used as a beam, for example. In this case, the pedestal may include a main body portion attached to a wall surface and the like, and a tubular projecting portion projecting horizontally from the main body portion. That is, the foundation structures according to the first and second embodiments described above are examples of the steel pipe structure mounting structure according to the embodiment of the present invention, and in addition to various types of steel pipe structure mounting structures. The present invention can be applied. In the above example, the illuminating lamp 30 is described as including the foundation structure 1 according to the first embodiment. However, it is also possible to configure an illuminating lamp including the foundation structure 11 according to the second embodiment. It is.

(Example where the pedestal is divided into multiple parts)
5A and 5B are cross-sectional views showing a first example in which the pedestal is divided into a plurality of portions in the embodiment of the present invention as described above. The relationship of each figure is shown by the VA-VA line and the VB-VB line. In the illustrated example, the pedestal 3 is divided into two parts 3 a and 3 b along a plane including the axis of the tubular protrusion 5. Each of the two portions 3a and 3b includes divided base plates 4a and 4b and divided tubular protrusions 5a and 5b. The two parts 3a and 3b of the pedestal 3 may be joined in advance by welding, for example, or may not be joined until the tubular projecting portion 5 is press-fitted into the tapered steel pipe 2 (see FIG. 1 and the like). Good. The supporting pressure acting in the radial direction of the steel pipe between the outer peripheral surface 51 of the tubular projecting portion 5 and the inner peripheral surface 2a of the tapered steel pipe 2 acts in a direction in which the two portions 3a and 3b of the base 3 are pressed toward each other. It is possible to maintain the state where the two portions 3a and 3b are joined without using welding or the like.

  When joining the two parts 3a and 3b of the base 3 without using welding or the like as described above, a water stop material may be applied to the joint surfaces 3aa and 3ba. By applying a water-stopping material to the joint surfaces 3aa and 3ba at the tubular projecting portion 5, for example, water droplets derived from rain water and the like and transmitted from the upper part of the tapered steel pipe 2 to the inner peripheral surface 2a It can prevent entering the inside of the tubular protrusion part 5 along the gap. Further, by applying a water-stopping material to the joint surfaces 3aa and 3ba at the base plate 4, rainwater and the like enter the inside of the tubular projecting portion 5 from the base plate 4 side through the gap between the joint surfaces 3aa and 3ba. Can be prevented. The waterstop material is, for example, an elastomer having water expandability, for example, natural rubber or chloroprene rubber blended with a high molecular substance such as starch, cellulose, polyacrylate, or polyvinyl alcohol. Etc. can be used.

  FIG. 5C is a diagram showing a modification of the example shown in FIGS. 5A and 5B. In the example shown in FIG. 5C, the pedestal 3 is divided into four portions 3 c, 3 d, 3 e, and 3 f along a plane that includes the axis of the tubular protrusion 5. Each of the four portions 3c to 3f includes divided base plates 4c, 4d, 4e, and 4f and divided tubular protrusions 5c, 5d, 5e, and 5f. In addition, since it is the same as that of the example shown by FIG. 5A and FIG. 5B about another point, the overlapping description is abbreviate | omitted.

  6A and 6B are diagrams showing another modification of the example shown in FIGS. 5A and 5B. The relationship of each figure is shown by the VIA-VIA line and the VIB-VIB line. In the illustrated example, the pedestal 3 is divided into two parts 3a and 3b as in the example of FIGS. 5A and 5B. However, in this example, protrusions 3ab and grooves 3bb having shapes corresponding to each other are formed on the joint surfaces 3aa, 3ba of the two portions 3a, 3b. When the two portions 3a, 3b of the base 3 are joined without using welding or the like by engaging the protrusion 3ab and the groove 3bb with each other, when the tubular protrusion 5 is press-fitted into the tapered steel pipe 2, the two It becomes easy to maintain the state in which the portions 3a and 3b are combined. Further, in each of the tubular projecting portion 5 and the base plate 4, it is possible to prevent water droplets or rainwater from entering the inside of the tubular projecting portion 5. In addition, in this example, a water stop material may be applied to the joint surfaces 3aa and 3ba of the two portions 3a and 3b including the protrusion 3ab and the groove 3bb.

  FIG. 7 is a longitudinal sectional view showing a second example in which the pedestal is divided into a plurality of portions in the embodiment of the present invention. In the illustrated example, the pedestal 3 is divided into two parts 3p and 3q on a plane perpendicular to the axis of the tubular protrusion 5. One portion 3p includes a base plate 4 and a divided tubular protrusion 5p. The other portion 3q includes a divided tubular protrusion 5q. The two portions 3p and 3q of the pedestal 3 may be joined in advance by welding, for example, or may not be joined until the tubular projecting portion 5 is press-fitted into the tapered steel pipe 2 (see FIG. 1 and the like). Good. If the joining surfaces 3pa and 3qa are above the lower end of the tapered steel pipe 2, the supporting pressure acting in the radial direction of the steel pipe between the outer peripheral surface 51 of the tubular projecting portion 5 and the inner peripheral surface 2a of the tapered steel pipe 2 is Since the two parts 3p and 3q of the pedestal 3 act in a direction in which the two parts 3p and 3q are pressed toward each other, it is possible to maintain the joined state of the two parts 3p and 3q without using welding or the like. Similarly to the above example, when the two portions 3p and 3q are joined without using welding or the like, a water stop material may be applied to the joint surfaces 3pa and 3qa.

  8A and 8B are diagrams showing a modification of the example shown in FIG. The relationship of each figure is shown by the VIIIA-VIIIA line and the VIIIB-VIIIB line. FIG. 8C is a diagram illustrating a state where the two portions illustrated in FIG. 8A are engaged with each other. In the illustrated example, the pedestal 3 is divided into two parts 3p and 3q as in the example of FIG. However, in this example, as shown in FIG. 8A, a groove portion 3pb and a flange portion 3qb having shapes corresponding to each other are formed in the two portions 3p and 3q. The groove portion 3pb is formed on the inner peripheral surface of the tubular projecting portion 5, and extends in parallel with the joint surface 3pa, that is, in the circumferential direction of the tubular projecting portion 5. As shown in FIG. 8B, the joint surface 3pa and the groove 3pb communicate with each other through cutouts 3pc formed at four locations. The flange portions 3qb are formed at four locations corresponding to the cutout portions 3pc. After inserting the flange portion 3qb through the notch portion 3pc, the flange portion 3qb can be engaged with the groove portion 3pb by rotating the portion 3q around the axis of the tubular protrusion 5 with respect to the portion 3p. By engaging the two portions 3p and 3q with each other using the groove portion 3pb and the flange portion 3qb in this way, bending against the tapered steel pipe 2, that is, against stress in a direction perpendicular to the axis of the tubular protruding portion 5 is counteracted. Thus, the state in which the two portions 3p and 3q are joined can be maintained.

  FIG. 9 is a diagram showing another modification of the example shown in FIG. In the illustrated example, the pedestal 3 is divided into two parts 3p and 3q as in the example of FIG. However, in this example, flanges 3pd and 3qd are formed on the joint surfaces 3pa and 3qa of the two portions 3p and 3q, and the flanges 3pd and 3qd are fastened to each other by a bolt 3pe and a nut 3qe. In this example, by arranging a plurality of sets of bolts 3pe and nuts 3qe, compression or tension (stress in the axial direction of the tubular protrusion 5) is applied to the tapered steel pipe 2 without welding between the two portions 3p and 3q. The two parts 3p and 3q are kept joined against bending, stress (stress in a direction perpendicular to the axis of the tubular protrusion 5), and rotation (moment about the axis of the tubular protrusion 5). can do.

  By dividing the pedestal 3 into a plurality of parts as in the above example, the size of each part is reduced and the manufacture and transportation of the pedestal 3 are facilitated. Even when the pedestal 3 is divided into a plurality of portions, the tapered steel pipe 2 and the pedestal 3 can be reliably friction-bonded and support-bonded as in the first to third embodiments. Although a plurality of portions of the pedestal 3 may be welded, a welded portion is not formed between the tapered steel pipe 2 and another member, so that stress concentration on the welded portion hardly occurs. In addition, water droplets or rainwater can be formed on the inner side of the tubular projecting portion 5 by bringing the plurality of portions of the pedestal 3 into close contact with each other, providing the engagement structure as described above, or applying a water stop material to the joint surface. Can be prevented, so that the influence of environmental conditions such as rainwater can be reduced as in the first to third embodiments. Further, by dividing the pedestal 3 into a plurality of parts other than the boundary between the base plate 4 and the tubular projecting portion 5, the base plate 4 and the tubular projecting portion 5 are made of cast steel in the same manner as in the first to third embodiments. It is possible to form continuously by using and reduce stress concentration on the welded portion. Further, by reducing the thickness of the tubular projecting portion 5 toward the upper end portion, the weight of the pedestal 3 can be reduced while reducing the stress applied to the lower end portion of the tubular projecting portion 5. The point which can attach an electrical component to a surrounding surface and can reduce the opening part formed in the taper steel pipe 2 is the same as that of the example of 1st to 3rd embodiment.

  Although exemplary embodiments of the present invention have been described above, the technical scope of the present invention is not limited to these embodiments, and the present invention is within the scope of the technical idea described in the claims. Including embodiments that have been changed or modified in accordance with what can be conceived by those having ordinary skill in the art.

  For example, in the above-described embodiment, the tapered steel pipe is described as having a uniform tapered shape over the entire length. However, for example, the taper angle may change in the length direction of the tapered steel pipe. In this case, the outer peripheral surface of the tubular protrusion of the pedestal has a tapered shape corresponding to the vicinity of the end of the tapered steel pipe into which the tubular protrusion is press-fitted. In addition, the tapered steel pipe may not have a tapered shape partially, for example, at an end portion on the opposite side to the foundation structure.

  Further, for example, in the above embodiment, the basic structure including the tapered steel pipe and the base formed of cast steel has been described. However, the material of the tapered pipe and the base is not limited to steel, and as described in the above embodiment. Any material that generates elastic deformation may be used. Further, the tapered tube and the pedestal may be formed of different materials.

  Further, for example, in the above-described embodiment, the base plate and the tubular protrusion of the pedestal are described as being formed continuously by casting. However, the base plate and the tubular protrusion are continuously formed by a method other than casting. Also good.

  DESCRIPTION OF SYMBOLS 1,11 ... Base structure, 2 ... Tapered steel pipe, 3 ... Base, 4 ... Base plate, 5 ... Tubular protrusion, 51 ... Outer peripheral surface, 52 ... Inner peripheral surface, 53 ... Diagonal surface, 54 ... Groove, 7 ... Electricity Parts, 30 ... lights.

Claims (9)

A pipe structure mounting structure,
A tapered tube having a tapered shape over its entire length;
A pedestal including a main body part and a tubular projecting part protruding from the main body part and press-fitted into the inner peripheral surface side of the tapered tube,
The outer peripheral surface of the tubular protrusion has a tapered shape corresponding to the inner peripheral surface of the tapered tube,
The outer diameter of the tubular projecting portion is a second outer diameter smaller than the inner diameter of the end opening from the first outer diameter larger than the inner diameter of the end opening of the tapered tube due to the tapered shape of the outer peripheral surface. Mounting structure that changes up to.   The mounting structure according to claim 1, wherein the main body portion and the tubular projecting portion of the pedestal are formed continuously.   3. The attachment structure according to claim 1, wherein a thickness of the tubular projecting portion is reduced toward an end portion on a side opposite to the main body portion.   The attachment structure according to any one of claims 1 to 3, further comprising an electrical component attached to the inner peripheral surface of the tubular protrusion.   The mounting structure according to any one of claims 1 to 4, wherein the tubular projecting portion includes a beveled surface formed following the outer peripheral surface at an end opposite to the main body portion.   The mounting structure according to claim 5, wherein the tubular projecting portion has a groove connected to the oblique surface and extending along the outer peripheral surface in the longitudinal direction of the tubular projecting portion.   The mounting structure according to claim 1, wherein the main body is a base plate.   The mounting structure according to claim 1, wherein the pedestal is divided into a plurality of portions.   The pipe structure containing the attachment structure of any one of Claims 1-8.

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