JP2013158189A - Cross arm - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent failures in power transmission and distribution which are caused by snow coverage on an overhead power transmission/distribution installation.SOLUTION: A cross arm 1a of this invention is installed on an electric pole 2 etc. for aerial wiring of a power transmission/distribution line 11 and is used for suspending the power transmission/distribution line 11. The cross arm 1a of this invention is vertically placed on a concrete pole 2 installed in parallel with a gravity direction. A plate like steel plate is used as an electric wire support plate 6a, and the electric wire support plate 6a is vertically attached to a cross arm material 4 serving as a main beam of the cross arm 1a. The electric wire support plate 6a is fixed by fitting the steel plate, where a hole having the same shape with a cross section of the cross arm material 4 is formed, in a predetermined portion of the cross arm material 4 and welding those portions.

Description

  The present invention relates to a brace that is installed on a utility pole for an overhead transmission / distribution line and for laying the overhead transmission / distribution line, and more particularly to an armrest that copes with snow in winter and the like.

  When a power line such as a power transmission line or a distribution line is installed on a steel tower or a utility pole, it is generally performed to attach the electric wire to a wire support portion of a brace via an insulator.

  For example, in Patent Document 1, a transmission line is connected to a mounting plate (electric wire support plate) fixed to a support arm of a steel tower with a bolt via a tension insulator, and the transmission lines are electrically connected with a jumper line. It is described that.

  Here, the example which constructs an overhead transmission / distribution electric wire on a utility pole is demonstrated in detail. FIG. 2 is an explanatory view of a conventional arm. In the conventional arm 1b, an overhead wire 1b is attached near the top of two electric poles (concrete poles) 2, and an anti-lightning ground wire member 3 is attached on the top of one concrete pole 2. It has been. In this example, the concrete pole 2 is installed parallel to the direction of gravity.

  The arm metal 1b is composed of two arm metal members 4 constituting the main beam, a reinforcing arm metal auxiliary material 5, and an electric wire support plate 6b for attaching an overhead wire. A beam formed by fastening an arm metal member 4 made of two angle members with an auxiliary member 5 for arm metal members made of a plurality of angle members is substantially perpendicular to the two concrete poles 2 and two beams are formed. An angle member (arm metal member 4) is stretched so as to sandwich each concrete pole 2, and the arm member 1b is attached to the utility pole 2 via a band 7 for the arm member. These two arm metal bands 7 are wound around each concrete pole 2 and fixed, and the arm metal material 4 is attached to these arm metal bands 7 with bolts and nuts. Usually, it is further fixed at a predetermined position by a fixing bolt or through bolt of the utility pole.

  In this case, since it is a three-wire wiring, a total of three electric wire support plates 6b in which the transmission and reception sides are integrated are fixed to the brace material 4. In this example, three wire support plates 6b made of angle material of a predetermined length are attached to bolts, at a total of three locations on the upper surface of both ends and the central upper surface of each of the two angle members (arm metal member 4). It is attached with a nut, and these electric wire support plates 6b play a role of fastening the arm metal member 4 together with the other arm metal auxiliary members 5. A transmission / distribution electric wire 12 is installed on these electric wire support plates 6b via insulators 11. Note that the transmission / distribution wires 12 on the power transmission side and the power reception side are electrically connected by a jumper wire 14.

  Further, two ground wire member bands 8 are wound around and fixed to the upper portion of one concrete pole 2, and the ground wire member 3 is attached to these ground wire member bands 8 by bolts and nuts. Usually, it is further fixed at a predetermined position by a fixing bolt or through bolt of the utility pole. A ground wire 13 is installed on the top of the ground wire member 3.

  In addition, in the winter season in cold regions, if icing or snowing excessively occurs on overhead power transmission and distribution facilities, disconnection accidents or short circuit accidents due to increased weight of the wires, galloping vibrations, three jumps, etc. Since there is a possibility of column collapse, etc., studies have conventionally been made on preventing icing and snow accretion. For example, Patent Documents 2 and 3 describe an invention relating to a snow-prevention plate and a snow-prevention cover as snow-prevention on a steel tower, and Patent Document 4 describes an invention relating to snow-prevention on overhead lines and galloping vibration prevention. ing.

JP-A-4-301325 Japanese Patent Laid-Open No. 5-263552 JP 2006-200170 A JP 2006-223064 A

  As described above, studies have been made on the prevention of icing and snow accretion on power transmission and distribution lines and steel towers, and various measures have been taken in cold regions. In the case of an aerial transmission / distribution facility such as the conventional example shown in FIG. 2, if snowfall continues, snow falls on the arm 1 b. If the weight of the snow is excessive, there is a risk that power transmission and distribution will be hindered. Therefore, especially in heavy snowfall areas, it is important to take measures against snow for such overhead power transmission and distribution equipment.

  FIG. 4 shows an example in which a large amount of snow has been snowed at a conventional brace. In the case of the conventional aerial transmission / distribution facility shown in FIG. 2, the crown on the angle member composed of the arm metal material 4 of the arm metal 1b, the auxiliary material 5 for the arm metal and the wire support plate 6b due to a large amount of snowfall or the like. When the amount of snow increases, the distance between the angle members such as the arm metal member 4 is narrow, so that snow may grow and form a bridge between the angle members. Once the snowfall forms a bridge between the angle members, the area where the arm 1b receives snowfall increases, and the subsequent increase in the amount of snow and further growth of snowfall are likely to proceed. If these snowfall and snowfall grows due to further snowfall or the like before the snowfall and snowfall decrease due to melting snow or snowfall, the snow becomes snowfall over the entire portion of the arm 1b as shown in FIG. When the weight of the snow is excessive, the arm 1b is deformed, which causes problems in power transmission and distribution.

  The arm metal 1b is designed to have sufficient strength in consideration of the weight of the transmission / distribution cable 12 and the weight of snow on the transmission / distribution cable 12, but the load on the head of the utility pole 2 is If it becomes excessive, the utility pole 2 is easily collapsed. Therefore, it is desirable that the arm metal 1b is light, including the cost, and it is often made of a relatively light steel.

  If each member of the arm metal 1b is made of a thick steel material to increase the strength, it is possible to prevent the arm metal 1b from being bent due to snow but it is desirable to avoid an increase in the weight of the arm metal as much as possible. Therefore, it is desirable to take measures to prevent snow cover on the brace 1b.

  FIG. 3 is an explanatory view of an improved armrest. This improved arm metal 1c has a reduced snow cover by reducing the area that receives snowfall compared to the conventional arm metal 1b. The improved arm metal 1c is composed of one arm metal material 4 that constitutes the main beam, an arm metal auxiliary material 5 that reinforces the attachment portion to the utility pole 2, and an electric wire support plate 6c for attaching an overhead wire. ing. The arm metal material 4 and the arm metal auxiliary material 5 are manufactured using channel steel. The arm metal 1c is such that the arm metal material 4 serving as the main beam is substantially perpendicular to the two concrete poles 2 and each of the two concrete poles 2 is sandwiched between the two arm metal auxiliary materials 5. The arm 1c is attached to the utility pole 2 via the arm metal band 7. Two armband bands 7 are wound around each concrete pole 2 and fixed, and the armband material 4 and the armband auxiliary material 5 are attached to these armband bands 7 by bolts and nuts. Further, as in the conventional example, it is fixed at a predetermined position by a fixing bolt or a through bolt of a utility pole. As in the conventional example, the concrete pole 2 is installed parallel to the direction of gravity.

  Also in this case, since it is a three-wire wiring, the wire support plate 6b made of a total of three steel plates integrated with the transmission and reception sides has a total of 3 upper surfaces at both ends and a central upper surface of one channel steel (arm metal member 4). At the location, it is attached with bolts and nuts. A transmission / distribution electric wire 12 is installed on these electric wire support plates 6b via insulators 11. Note that the transmission / distribution wires 12 on the power transmission side and the power reception side are electrically connected by a jumper wire 14.

  Further, similarly to the conventional example, two ground wire member bands 8 are wound around and fixed to the upper portion of one concrete pole 2, and the ground wire member 3 is fastened to the ground member band 8 by bolts and nuts. Further, it is fixed at a predetermined position by a fixing bolt or a through bolt of the utility pole. A ground wire 13 is installed on the top of the ground wire member 3.

  The snowfall area of the improved arm metal 1c is such that, even when snowfall forms a bridge between the arm metal auxiliary material 5 and the arm metal material 4, the snow accumulation of the conventional arm metal 1b forms a bridge between the angle members. Compared to the snowfall area of, it has been greatly reduced, and it can be seen that a large amount of snow can hardly occur. However, even in the improved arm 1c, the portion of the wire support plate 6c is likely to snow, and if the snow formation forms a bridge between the transmission and reception side insulators around the wire support plate 6c, it is incompatible with the snow near the power pole. Since snow can grow over time and become snow cover over the entire area of the brace, which is comparable to that shown in FIG. 4, it is desirable to consider further snow cover prevention measures, particularly in heavy snow areas.

  That is, the main object of the present invention is to prevent a power transmission / distribution failure due to a snow cover on an overhead power transmission / distribution facility, and in particular, a large amount of snow cover on the upper part of a brace for suspension of a power transmission / distribution line. It is to provide a brace that is suitable for use in heavy snow areas and that is unlikely to snow.

  The present invention is a brace that is installed on a power pole or the like for overhead wiring of a transmission / distribution line and suspends the transmission / distribution line as in the prior art.

  In the arm metal of the present invention, the wire support plate for attaching the overhead wire is attached to the arm metal material constituting the main beam in the same manner as the above-described improved arm metal. However, the improved wire support plate is attached to the upper surface of the bracelet, and the plate surface is arranged perpendicular to the gravity. There is a possibility that a bridge is formed between the insulators on the transmission / reception side centering on the plate. On the other hand, the electric wire support plate of the present invention is configured to reduce the area that receives snowfall as much as possible so that it is difficult for snowfall to occur.

  That is, in the brace of the present invention, the plate-shaped electric wire support plate is attached to the bracelet so that the plate surface is installed parallel to the direction of gravity.

  Further, in the arm metal of the present invention, the shape metal is used as the arm metal material, the steel plate having a predetermined shape corresponding to the number of transmission / reception wires is used as the wire support plate, and the shape steel of the arm metal material is used for the steel plate of these wire support plates. A hole having the same shape as that of the cross section is formed, and the electric wire support plate is fitted into a predetermined portion of the brace through the hole and fixed by welding or the like.

  Further, in the arm metal of the present invention, the electric wire support plate is fitted into the arm metal material, welded and integrated, Zn plated, and a snow-sliding paint is applied thereon.

  That is, the arm metal of the present invention is attached to the arm metal material so that the plate surface of the electric wire support plate is installed in parallel to the direction of gravity, and the area of the electric wire support plate that receives snowfall is small, so there is less snowfall. Easy to fall snow. Therefore, it is harder for snow to occur at the location of the wire support plate than before, and the amount of snow on the armrest is prevented from becoming excessive, and obstacles to power transmission and distribution such as short-circuiting and disconnection accidents due to bending of the armrest etc. Is prevented from occurring. The present invention is advantageous in terms of cost because it is possible to suppress the bending of the arm metal without increasing the strength of the arm metal using the thick section steel. In addition, since the weight of the brace is not increased, a conventional design and construction utility pole can be used.

  Furthermore, since the electric wire support plate is fitted into the brace and fixed by welding, the attachment portion of the electric wire support plate has high strength and is resistant to corrosion by Zn plating. In addition, the application of the snow-sliding paint prevents snow from accumulating, makes it easier for snow to fall, and further suppresses snow from snow.

It is explanatory drawing of the arm bracket of this invention. (Example) It is explanatory drawing of the conventional arm bracket. (Conventional example) It is explanatory drawing of the improved brace. (Improvement example) It is explanatory drawing of the condition where it snowed on the location of the conventional bracelet. (Conventional example)

  The present invention relates to a brace that is installed on a power pole or the like for aerial wiring of a transmission and distribution line, and the plate surface of a plate-like wire support plate for suspending the transmission and distribution line via an insulator is a brace. It is attached to be installed in parallel to the direction of gravity. Furthermore, it is preferable that the arm metal is Zn-plated and a snow-sliding paint is applied thereon.

  Since the arm metal of the present invention is attached to the arm metal material so that the plate surface of the electric wire support plate is installed in parallel to the direction of gravity, a plate thickness surface appears as an upper surface during snowfall. Therefore, since the area where it is easy to snow is reduced, it is difficult for snow to occur, snow is likely to fall, the growth of snow is suppressed, and the snow is also suppressed. Further, the snow-sliding paint further prevents snow accretion, snow falls easily, and snow can be further suppressed.

  FIG. 1 is an explanatory view of a brace according to the present invention, and shows a state in which a power transmission / distribution line is installed. An example of the present invention will be described in detail with reference to the drawings. The brace 1a of the present invention is installed on the utility pole 2 and the like for overhead wiring of the transmission / distribution line 11 and suspends the transmission / distribution line 11 as in the prior art. Also in this case, as in the conventional example, the concrete pole 2 is installed in parallel with the direction of gravity, and the main beam of the brace 1a is arranged perpendicular to the concrete pole 2. As shown in FIG. 1, the electric wire support plate 6a of the present invention uses a plate-like steel plate as in the improved type, but the electric wire support plate 6a is vertically attached to the arm metal member 4 serving as the main beam. Here, the electric wire support plate 6a fits the steel plate which opened the hole of the same shape as the cross section of the arm metal material 2 in the predetermined location of the arm metal material, and fixes it by welding or the like.

  The electric wire support plate 6a needs to have sufficient strength to suspend and support the transmission / distribution electric wire, and there is a limit to reducing it for the construction of the suspension work. However, when the electric wire support plate 6a is attached vertically to the brace 4 in this way, the plate surface is installed parallel to gravity, and the upper surface during snowfall becomes the plate thickness surface (side surface) of the steel plate. The area of the upper surface that is likely to snow is reduced. Moreover, since the steel plate shape of the electric wire support plate 6a has a relatively large degree of freedom, it is possible to increase the inclined surface by reducing the horizontal surface of the upper surface during this snowfall. The inclined surface is less likely to snow and more likely to fall than the horizontal surface, and can be designed with more inclined surfaces, which is more advantageous for preventing snow cover.

  The electric wire support plate 1a is formed by cutting a plate having a predetermined shape from a steel plate, forming a hole having a cross-sectional shape of the brace 4 on the plate, and further forming a hole for attaching the insulator 11. Cutting of the steel plate and formation of the holes can be performed collectively by laser processing. The order of each processing is free. The wire support plate 6a formed here is fitted into the brace material 4, and is welded and fixed at a predetermined location. For fixing, direct welding between the wire support plate 6a and the arm metal member 4 is easy to perform, but a separate fixture may be used.

  Further, as shown in FIG. 1, by attaching the brace reinforcement material 9 to an appropriate portion of the brace material 4, the strength of the brace 1a can be increased, and the bending of the brace 1a due to snow can be prevented.

  Usually, the metallurgy is treated with rust prevention of Zn plating, but by applying a snow-sliding paint onto the Zn plating, it suppresses snowfall, promotes snowfall, and prevents excessive snowfall. Can help.

  Various paints are commercially available as snow-sliding paints, and these may be selected as appropriate. In particular, it is considered that the snow-sliding paint for tin is also suitable for Zn-plated steel. In the following examples, Dainippon Paint Co., Ltd., trade name: V Freon # 100 was used.

  Furthermore, in order to reduce the snow cover of the armrest part, snow cover prevention measures other than the location of the wire support plate are also effective. By attaching a conical or pyramid-shaped utility pole cap, it is possible to reduce snow snow on the location of the utility pole. Moreover, you may perform combined use with the attachment of a snow accretion prevention board like patent document 2, 3, a snow accretion prevention cover, etc. Further, as a countermeasure against snow accumulation in winter, it is preferable to use a countermeasure for preventing snow accretion to an overhead line and preventing galloping vibration as described in Patent Document 4, if necessary.

Example 1
A wire support plate 6a made of a steel plate (270 mm × 265 mm × 16 mmt) is fitted into the arm metal member 4 of the grooved steel (cross section C—150 mm × 75 mm × 9 mm × 12.5 mm × length 5.3 m) constituting the main beam. Then, an arm metal 1a composed of an arm metal auxiliary material 5 which is welded and fixed to three places and plated with Zn, and a grooved steel (cross section C-150 mm × 75 mm × 9 mm × 12.5 mm × length 1.5 m). The utility pole as shown in FIG. 1 was constructed by attaching it to the utility pole 2 with a bracelet band 7. The ground wire member 3 uses channel steel (cross-section C-125 mm × 65 mm × 6 mm × 8 mm) and has a height of 2.3 m. Moreover, the utility pole 2 uses two concrete poles with a diameter of 274.7 mm, and the interval between the utility poles 2 is 2.6 m.

(Example 2)
All the dimensions, etc. are the same as in Example 1 except that the wire support plate 6a is welded and fixed to the arm metal member 4 and then the Zn plating is applied and then a snow-sliding paint (Dainippon Paint Co., Ltd., trade name: V Freon # 100) is applied. A utility pole was constructed.

(Conventional example)
An angle member (cross-section L-45 mm × 45 mm × 4 mm × length 1.1 m) is attached to the arm metal member 4 of the angle member (cross-section L−100 mm × 100 mm × 10 mm × length 5.3 m) constituting the main beam. An electric pole as shown in FIG. 2 was constructed by welding and using an arm 1b to which an electric wire support plate 6b of an angle member (cross section L-75 mm × 75 mm 6 mm × length 0.6 m) was attached with a bolt and a nut. The utility pole is the same as that of the first embodiment except for the brace 1b.

(Improved type)
A utility pole as shown in FIG. 3 was constructed in which a metal brace attached to the arm metal member 4 with bolts and nuts was attached to the arm metal member 4 vertically. Moreover, all the dimensions of each member are the same as Example 1 except having used the wire support plate in which the hole of a cross section is not formed.

(Observation of snow conditions)
In the situation where the electric poles of Examples 1 and 2 and the conventional examples and the improved type electric poles were constructed on a flat ground without a high building in the surrounding area and the transmission lines were laid over, the snow-covering situation of the armrest portions of the electric poles was observed.

  Observing the progress of snow cover, generally, (a) snow cover from the wire support plate to the insulator, (b) from the top of the power pole to which the ground wire member was attached to the arm bracket attachment to the power pole Snow covered, (c) the snow covered from the top of the power pole to the armrest attachment to the power pole is formed first, and it seems that the growth and snowfall of the snow covered in each place are repeated. When the snow cap grows further, the snow caps of the above (a), (b), and (c) are connected not only on the arm metal but also in the width direction. The snow cover over the entire length of was observed.

  In the case of the conventional example, early snow formation forms a bridge between the brace members 4 and the area that receives snowfall increases, so the growth of the snow can be fast, and the width that wraps up to a part of the insulator as shown in FIG. Snow cover was observed over the entire length of the bracelet. As shown in FIG. 4, when snow is observed over the entire length of the armature with a width that wraps up to a part of the insulator, there is a risk that the armature may be damaged if the amount of snow covered further increases. The snow on the power pole was removed.

  In the case of the improved type and Examples 1 and 2, the snow cover near the utility poles in (b) and (c) above is because the bracelet and the bracelet auxiliary material are close to each other near the utility pole. Snow accretion forms a bridge, and a large amount of snow is observed early in this area. However, even in the situation where snow canopy is observed as shown in FIG. 4 with the conventional utility pole, in the case of Examples 1 and 2, the snow canopy with a width that wraps up to a part of the insulator stops between the power poles. Growth up to the full length of the brace was not observed. In the case of Example 2, there was no growth of snow on the entire surface even between the utility poles. In the case of the improved type, the growth of the crown snow is slower than in the conventional type. However, during heavy snowfall, the snow crown grows from the above (a) wire support plate to the insulator, and in the vicinity of the utility poles in the above (b) and (c) A large amount of snow was observed over the entire surface as shown in Fig. 4.

  In the case of Examples 1 and 2, it was confirmed that the growth of snow from the (a) wire support plate to the insulator was slow even when compared with the improved type. Even in a situation where snow was observed over the entire length of the arm metal with a width that wraps up to a part of the insulator as shown in FIG. The width of the snow is so narrow that it wraps up to a part of the insulator, and the snow canopy is between the two power poles (between one power pole and the power support plate between the power poles and from this power support plate to the other power pole. And no snow growth was observed from one power pole to the wire support plate at the end of the armrest and from the other power pole to the wire support plate at the end of the other armrest.

  As for the bending of the brace due to a large amount of snow, it is difficult for the arm to bend at the arm between the two power poles, which is a double-supported beam structure. In the arm metal part between the utility pole and the end part of the arm metal which has a cantilever structure, there is a high possibility that the arm metal is bent particularly in the vicinity of the power pole of the arm metal. Therefore, as in Examples 1 and 2, it is difficult for snow growth to occur from one power pole to the wire support plate at the end of the armrest and from the other power pole to the wire support plate at the other end of the armrest. It can be seen that the effect of preventing the bending of the bracelet is very large. Further, in the case of Example 2, the width of the snow covered was narrower than that of Example 1, the amount of snow covered was small, snowfall seemed to be early, and the snow was reduced earlier. In the case of Example 2, it is considered that the effect of applying the snow-sliding paint on the entire surface of the brace greatly contributed.

1a (invention) arm metal 1b (conventional) arm metal 1c (improved) arm metal 2 utility pole, concrete pole 3 ground wire member 4 arm metal material 5 arm metal auxiliary material 6a (invention) electric wire support Plate 6b Wire support plate 6c (conventional example) Wire support plate 7 Armband 8 Ground wire member band 9 Reinforcement plate 11 Insulator 12 Power distribution wire 13 Ground wire 14 Jumper wire 21 Snow covered

Claims (4)

  A brace that is installed for overhead wiring of transmission and distribution wires, and is attached to the brace so that the plate surface of the plate-like wire support plate for attaching the overhead wire is installed parallel to gravity. A bracelet.   The bracelet according to claim 1, wherein the wire support plate and the brace material are plated with Zn and further coated with a snow-sliding paint.   In the method of manufacturing a brace that is installed for aerial wiring of a transmission and distribution wire, the steel wire is used as a brace material, and a number of steel plates having a predetermined shape corresponding to the number of transmission and reception wires are used as a wire support plate. An arm having the same shape as the cross-section of the shape steel of the arm metal member is formed in a steel plate of the plate, and the electric wire support plate is fitted into a predetermined portion of the arm metal material through the hole and fixed by welding. Gold manufacturing method.   4. The method of manufacturing an arm metal according to claim 3, wherein after the welding and fixing, the wire support plate and the arm metal material are plated with Zn and further coated with a snow-sliding paint.