JP5858816B2 - Steel pipe train wire pillar - Google Patents

Description

  The present invention relates to a steel pipe train line pillar for supporting a railway overhead wire, and more particularly to a steel pipe train line pillar that can be built even in an area where corrosion due to sea breeze is severe.

  Conventionally, concrete poles having excellent corrosion resistance have been used as train line poles for railways. However, after the Great Hanshin-Awaji Earthquake, concrete columns were found to have problems with earthquake resistance, so steel pipe train wire columns are being studied.

  Of course, steel pipe train poles are required to have corrosion resistance, and particularly in areas where the corrosion is severe due to salt that comes close to the coast and rides on the sea breeze.

  Therefore, as shown in Patent Document 1, the present applicant has first developed a steel pipe train wire pole in which galvanization and a microporous silicate-based paint are applied to the outer surface to improve corrosion resistance. However, since this steel pipe train wire pole seals both ends of the steel pipe to prevent internal corrosion, it is naturally an integral structure. For this reason, long steel pipes had to be transported to the site and built, and there were cases where transportation was not easy depending on topography and road conditions.

JP 2003-253471 A

  Accordingly, an object of the present invention is to solve the above-described conventional problems, and to provide a steel pipe train wire pole which does not need to transport a long steel pipe to the site and has excellent corrosion resistance.

The present invention made to solve the above problems has a length of 5 to 7 m, a steel pipe having a tapered tube-shaped portion formed at the end, and a length of 5 to 7 m. a steel pipe catenary posts for supporting the railway overhead line that engaged against a steel pipe expanded portion tapered to the ends is formed a long hole for bolt insertion vertically into the expanded pipe portion is formed The contracted tube portion and the expanded tube portion are fastened by a bolt that penetrates the bolt insertion elongated hole, and the inner surface and the outer surface of these steel tubes are covered with a molten zinc aluminum magnesium alloy plating layer. It is characterized by this.

  In addition, as described in claim 2, it is preferable that the taper ratio between the contracted tube portion and the expanded tube portion is 1/100 to 1/65. Moreover, it is preferable that the axial direction length of the said contraction pipe part and the said pipe expansion part is 2-4 times the steel pipe diameter D like Claim 3.

Further as in claim 4, molten zinc aluminum magnesium alloy plating layer is provided with a hot dip galvanized steel pipe is preferably one which further comprises a hot-dip Zn-Al-Mg alloy plating, also as of claim 5 Further, the hot-dip zinc aluminum magnesium alloy plating layer has a three-layer structure of a lower layer, an intermediate layer, and an upper layer, the lower layer is an Fe—Al alloy layer, the intermediate layer is mass%, Al: 4 to 20%, Fe: 0.1 to 15%, Mg: 0.1 to 5%, remaining Zn and an alloy layer composed of inevitable impurities, upper layer is Al: 4 to 20%, Mg: 0.1 to 5%, remaining Zn and An alloy layer made of inevitable impurities is preferable.

Since steel pipe catenary posts for supporting the railway overhead line of the invention is that combined to form a condensed tube portion and the expanded portion and below the steel tube having a length to tapered in 5~7m contact There is no need to transport a long steel pipe to the site as in the prior art. Further, by using the taper, it is possible to bond firmly with the cores accurately aligned. Furthermore, since these contraction pipe parts and the pipe expansion parts are fastened by bolts, there is no possibility that the joint will come off even when an external force such as strong wind or earthquake is applied.

The steel pipe train wire pole of the present invention having such a joining structure does not seal both end faces of the steel pipe, but the inner and outer surfaces of the steel pipe are covered with a hot dip zinc aluminum magnesium alloy plating layer. Even if the salt content is attached, it will not be corroded. Since this plating can be performed by immersion plating in a plating bath, it can be reliably formed on the inner surface and the outer surface.
The effects of the techniques described in the other claims will be sequentially described in the following embodiments.

It is a perspective view before joining showing an embodiment of the present invention. It is a perspective view after joining showing an embodiment of the present invention. It is an enlarged front view of a junction part. It is an expanded sectional view of a joined part.

In FIG. 1, 1 is a lower steel pipe whose lower part is embedded in the foundation, 2 is an upper steel pipe joined to the upper end of the steel pipe 1 and to which an overhead wire support fitting is attached. A tapered contracted tube portion 3 is formed at the upper end of the lower steel tube 1, and a tapered expanded tube portion 4 is formed at the lower end of the upper steel tube 2. As these steel pipes 1 and 2, steel pipes having an outer diameter of about 355 mm are used, and the length is suitably 5 to 7 m in order to facilitate transportation. In addition, although the hot dip zinc aluminum magnesium alloy plating layer is formed in the inner and outer surfaces of these steel pipes 1 and 2, this point will be described later.

  As shown in FIG. 2, by covering the tapered contracted tube portion 3 of the lower steel tube 1 with the tapered expanded portion 4 of the upper steel tube 2, it is driven by a hammer or pushed in the axial direction by a heavy machine. The contraction pipe part 3 is press-fitted into the pipe expansion part 4, and the steel pipes 1 and 2 are joined at the work site. In this embodiment, the contracted tube portion 3 is formed at the upper end of the lower steel pipe 1 and the expanded portion 4 is formed at the lower end of the upper steel tube 2. However, the expanded portion 4 is formed at the upper end of the lower steel tube 1. The contracted tube portion 3 may be formed at the lower end of the upper steel tube 2.

  In order to perform joining by such press-fitting, it is necessary that the taper ratios of the expanded pipe part 4 and the contracted pipe part 3 are the same, and this taper ratio is preferably in the range of 1/100 to 1/65. And Here, the taper rate is a value that means (diameter difference / axial length) of the tapered portion. If the taper ratio is smaller than this range, it becomes difficult to obtain an effective bonding force. On the other hand, if the taper ratio is larger than this range, the expanded pipe portion 4 is excessively expanded and the thickness thereof is reduced. If the taper ratio is set to 1/65 or less, the thickness reduction of the pipe expansion portion 4 can be kept within the allowable range (−12.5% or less) of the thickness variation of the steel pipe specified by JIS.

  Moreover, it is preferable to make the axial direction length of the pipe expansion part 4 and the contraction pipe part 3 into 2-4 times the steel pipe diameter D. If this length is less than twice the steel pipe diameter D, the joining length is insufficient and sufficient joining strength cannot be obtained. Conversely, if it exceeds 4 times, the expanded pipe portion 5 and the contracted pipe portion 4 become longer. This is not preferable because the taper processing cost of No. 2 increases.

  It has been confirmed that a large frictional force is generated on the joint surface by simply press-fitting the tapered tube-reduced portion 3 into the tube-expanded portion 4 as described above, and the steel pipe 1 and the steel pipe 2 are reliably joined. However, assuming a case where an external force such as strong wind or earthquake is applied, the contracted tube portion 3 and the expanded tube portion 4 are further fastened by bolts 5 as shown in FIGS.

  Since the steel pipes 1 and 2 have a length of 5 to 7 m, they cannot reach the inner surface of the joint after being joined. For this reason, a bolt insertion hole 6 is formed in the contracted tube portion 3 in advance, and a nut 8 is held by a nut holder 7. The nut 8 is held by the nut holder 7 so as not to rotate. For example, a square nut is preferable. Moreover, the nut holder 7 shall be previously attached to the inner surface of the contracted tube portion 3 by welding or the like.

  On the other hand, a long hole 9 for inserting a bolt is formed in the expanded portion 4 in the vertical direction as shown in FIG. The reason why the long hole 9 is formed is that the axial press-fitting depth (stop position) when the tapered tube-reduced tube portion 3 is press-fitted into the tube expansion portion 4 inevitably varies. However, there is no problem if the long hole 9 of about 50 mm is formed, and the bolt 5 may be inserted into the bolt insertion hole 6 from the long hole 9 and screwed into the nut 8 to be fastened.

  At the time of joining, the positions of the long holes 9 are made to correspond to the positions of the nuts 8 and are aligned in the circumferential direction, and then press-fitted. It is also possible to mark the appropriate positions of the steel pipes 1 and 2 for easy alignment. In the present embodiment, the two bolts 5 are arranged at the 180 ° position, but three or more bolts may be used. If the joint portion is fastened by the nut 5 and the nut 8 as described above, the function as a train wire pole is not impaired even when the frictional joint is loosened by some external force.

  The inner surface and the outer surface of the steel pipe 1 to which the nut holder 7 and the nut 8 are attached and the steel pipe 2 in which the long holes 9 are formed are covered with a hot dip aluminum alloy magnesium plating layer. This hot-dip zinc-aluminum-magnesium alloy plating layer is formed by hot-dip galvanizing a steel pipe and further hot-dip Zn-Al-Mg alloy plating. The hot-dip zinc-aluminum-magnesium alloy plating layer is described in Japanese Patent Application Laid-Open No. 2010-70810 relating to the applicant's application, and the outline thereof will be described as follows.

This molten zinc aluminum magnesium alloy plating layer is, for example, 350 g / m ² or more and has a three-layer structure of a lower layer, an intermediate layer, and an upper layer. Higher corrosion resistance can be obtained by increasing the plating amount of the molten zinc aluminum magnesium alloy to 350 g / m ² or more. The lower layer is an alloy layer of Fe and Al. Strictly speaking, any one of an Fe-Al alloy layer, an Fe-Al-Zn alloy layer, an Fe-Al-Si alloy layer, and an Fe-Al-Zn-Si alloy layer is used. is there. Such an alloy layer functions as a barrier layer that inhibits diffusion of Fe from the steel material, and can prevent formation of a brittle Fe—Zn alloy layer.

  The intermediate layer is an alloy layer composed of Al: 4 to 20%, Fe: 0.1 to 15%, Mg: 0.1 to 5%, the balance Zn and unavoidable impurities. Al is a component that improves the corrosion resistance, and this effect is exhibited at 4% or more, but even if it exceeds 20%, no improvement in the effect is observed, so 4 to 20%.

  The reason why the content of Fe is 0.1 to 15% is that if it is less than 0.1%, the effect of improving the plating adhesion is insufficient, and if it exceeds 15%, the improvement of the effect is not recognized.

The reason why Mg is set to 0.1 to 5% is that if it is less than 0.1%, the effect of improving the corrosion resistance is insufficient, and if it exceeds 5%, the plating layer becomes brittle and the adhesion decreases. Mg is finely dispersed in the plating layer as the MgZn ₂ phase, and during corrosion, the corrosion product of zinc becomes a protective film, improving the corrosion resistance.

  The upper layer is an alloy layer made of Al: 4 to 20%, Mg: 0.1 to 5%, the balance Zn and inevitable impurities. If Al is less than 4%, the effect of improving the corrosion resistance is insufficient, and oxidation of Mg in the plating bath cannot be prevented. Moreover, even if it exceeds 20%, the improvement of an effect is not recognized.

  The reason why Mg is set to 0.1 to 5% is that if it is less than 0.1%, the effect of improving the corrosion resistance is insufficient, and if it exceeds 5%, the plating layer becomes brittle and the adhesion decreases.

  This upper layer can be clearly distinguished from the lower layer and the intermediate layer containing Fe when the cross section of the plating layer is observed. In order to further improve the corrosion resistance, less than 0.8% Si can be added to the intermediate layer or the upper layer. Even if it exceeds 0.8%, no improvement in corrosion resistance is observed.

  The above-mentioned hot-dip zinc-aluminum-magnesium alloy plating layer has corrosion resistance superior to that of a normal hot-dip galvanization layer due to the action of Al and Mg, and there is no risk of corrosion even in a salt lightning protection area caused by sea breeze. In addition, the steel pipe train wire pole of the present invention is not sealed at the end, and salt may enter the inside of the steel pipe, but the above plating layer is formed on the inner and outer surfaces by immersion plating. There is no risk of internal corrosion.

As explained above, the steel pipe train line pillar for supporting the railway overhead wire according to the present invention is formed by joining the upper and lower steel pipes 1 and 2 having a length of 5 to 7 m. Since it can be connected, large cranes and many construction personnel are not required at the construction site of the railway line pole. In addition, since it is not necessary to transport long steel pipes to the site, transportation costs can be greatly reduced, and it is possible to easily build columns even in places where it is difficult to transport long steel pipes depending on topography and road conditions. In addition, since the contracted tube portion 3 and the expanded tube portion 4 are fastened by the bolt 5, there is no possibility that the joint is disconnected even when an external force such as a strong wind or an earthquake is applied. In addition, it is effective because a large crane can be used on the site due to the situation of the construction of the train line pillar, and even when the building pillar is assembled after being assembled long on site, the benefits of reducing transportation costs can be enjoyed in the same way.

  Furthermore, because the steel pipe train wire poles of the present invention are coated with the hot-dip zinc aluminum magnesium alloy plating layer on the inner and outer surfaces of the steel pipes 1, 2, they will not be corroded even if salt in the sea breeze adheres, There is no anxiety about corrosion resistance even in the coastal areas where salinity comes.

DESCRIPTION OF SYMBOLS 1 Steel pipe 2 Steel pipe 3 Reduced pipe part 4 Expanded pipe part 5 Bolt 6 Bolt insertion hole 7 Nut holder 8 Nut 9 Long hole

Claims (5)

A steel pipe having a length of 5 to 7 m and having a tapered constricted pipe portion formed at the end; and a steel pipe having a length of 5 to 7 m and having a tapered pipe expanding portion formed at the end; a steel pipe catenary posts for supporting the railway overhead line with combined contact, said the expanded pipe portion elongated hole for bolt insertion are formed in the vertical direction, the said reduced pipe portion expanded pipe portion and the bolt A steel pipe train wire pole, which is fastened by a bolt passing through a long hole for insertion, and whose inner and outer surfaces of these steel pipes are covered with a hot dip zinc aluminum magnesium alloy plating layer.   2. The steel pipe train wire pole according to claim 1, wherein a taper ratio between the contracted tube portion and the expanded tube portion is 1/100 to 1/65.   2. The steel pipe train wire pole according to claim 1, wherein axial lengths of the contracted pipe part and the pipe expanded part are 2 to 4 times a steel pipe diameter D. 3. Molten zinc aluminum magnesium alloy plating layer is provided with a hot dip galvanized steel pipe, provided with a further hot-dip Zn-Al-Mg alloy plating, claim 1, wherein the amount of alloy plating is 350 g / m ² or more The steel pipe train wire pole described in 1. The hot dip zinc aluminum magnesium alloy plating layer has a three-layer structure of a lower layer, an intermediate layer, and an upper layer, the lower layer is an Fe—Al alloy layer, the intermediate layer is mass%, Al: 4 to 20%, Fe: 0.00. 1-15%, Mg: 0.1-5%, balance Zn and alloy layer consisting of unavoidable impurities, upper layer is Al: 4-20%, Mg: 0.1-5%, balance Zn and unavoidable The steel pipe train wire pole according to claim 1, wherein the alloy layer is made of impurities and the alloy plating amount is 350 g / m ² or more.

Images