JP3172855B2 - Concrete pole having side opening and manufacturing method thereof - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a prestressed (pre-tensioned) concrete pole and a method of manufacturing the same.

[0002]

2. Description of the Related Art In FIG.
Are classified as communication, power, or a combination thereof. Further, in addition to those functions, a light 12, a sign, a traffic light, and the like are provided on an upper portion thereof. In the concrete pole 10, electric wires for controlling them are passed through the inside of the concrete pole. Then, the control electric wire or the electric power electric wire passing from the upper part is taken out from the side surface 14 of the concrete pole at the lower part. In this prestressed concrete pole, a large number of reinforcing bars are fixed at both ends as strength members, and tension is applied to the reinforcing bars while expanding the fixing portion (tensile force exerts compressive force on concrete. ing). Thus, the shape of the concrete pole is
The cross section is uniform over the entire length or continuously increases from the top to the bottom.

[0003] In FIG. 2, when an opening is formed in the surface portion of such a prestressed concrete pole at a distance equal to or greater than the internal reinforcing bar interval, the reinforcing bar 18 is cut in the middle to form a frame 19 for forming the opening. Attach. Then, for ease of manufacturing, the reinforcing bar 18 and the frame 19 cut in the middle are used.
And are not combined. For this reason, the reinforcing bars that should be arranged uniformly on the pole cross section become unbalanced, and are bent after forming (after the introduction of prestress) or have a directionality in strength. In particular, when lighting, signals, signs, and the like are assembled on a single pole, when these control devices are mounted, the opening formed in the lower surface of the concrete pole tends to be large.

[0004]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to form an opening in the side direction of a pole made of prestressed concrete, even if a reinforcing bar at the opening is cut off. An object of the present invention is to provide a concrete pole having an opening for eliminating the stability and bending of the strength of the pole and a method of manufacturing the same.

[0005]

In order to solve the above-mentioned problems, a prestressed concrete pole according to the present invention has a structure in which a frame 20 forming an opening is provided in a thick portion corresponding to the width of the frame 20. The placed reinforcing bar 22 is the fixing nut 2
4 (or by welding).

Further, in such a method of manufacturing a pole made of prestressed concrete, the reinforcing bar 22 disposed in the thick portion corresponding to the width of the frame 20 is divided into three portions 3.
It is divided into 0, 32 and 34 and they are connected to each other by a joint nut 36. At that time, the central portion 32, the joint nut 36, and the fixing nut 24 are arranged in the frame 20,
Then, after filling with concrete, centrifugal casting, and solidification, the central part 32 and the joint nut 36 in the frame 20 are formed.
, The end portion 30 is fixed to the frame 2 with the fixing nut 24.
Fix to 0.

Furthermore, another manufacturing method of the present invention is to connect (reinforce) the reinforcing bar 22 disposed in the thick portion of the portion corresponding to the width of the frame 20 with the frame 20 and then rotate the reinforcing bar 22 with concrete while rotating. Fill and form.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A method for manufacturing a prestressed concrete pole according to the present invention will be described below.

(A) In FIG. 3, except for the place where the frame 20 is to be placed, the column section is 9 (1) in this embodiment.
2-3) Arrange the rebars substantially evenly. The rectangular frame 20 is arranged at a place where the side opening is to be formed. As shown in FIG. 5, the frame 20 has a shape obtained by cutting a part of a thick cylinder, and a large window is opened on the side surface thereof, and this portion becomes a side opening of a concrete pole. .
In the upper and lower frames, a plurality of (three in the figure) holes are formed correspondingly. The size of this hole is such that the reinforcing bar 22 can penetrate.

(B) Three reinforcing bars 22 are arranged at the place where the frame 20 is to be arranged. This rebar 22
Divided into pieces. That is, an end portion 30, a central portion 32, and an end portion 34. This end portion 30
One end of the end portion 34 is externally threaded. When inserted into a frame 20 described later, the length of the frame 20
Only within the beam. Male threads are also cut at both ends of the central portion 32. In the joint nut 36,
A female screw matching this male screw is cut. Similarly, the fixing nut 24 is provided with a female screw that matches the male screw. Accordingly, the fixing nut 24 of the reinforcing bar 22 is screwed into the end portion 30 and the end portion 34, respectively. Further, in this state, the end portion 30 and the central portion 32,
Then, the central portion 32 and the end portion 34 are screwed together by joint nuts 36 to form one reinforcing bar. The fixing nut 24, the joint nut 36, the central portion 32, the joint nut 36, and the fixing nut 24 of the reinforcing bar 22 are arranged so as to enter the frame 20.

(C) After placing the reinforcing bar in the above state,
As before, concrete is poured while tensioning the rebar. Thereafter, the structure is solidified while rotating. Then, a hollow concrete pole is completed. Thus, by giving a tensile force to the rebar, a compressive force is applied to the concrete, and the strength as a pole can be maintained.

(D) The concrete pole thus formed has a hollow portion at the frame 20 and communicates with the hollow portion inside. Next, as shown in FIG.
The central part 32 and the joint nut 3 in this frame 20
After removing 6, the end portion 30 is fixed to the frame 20 with the fixing nut 24. With this configuration, the end portion 30 and the end portion 34 are connected to each other via the frame 20, and can continue to apply compressive force to the concrete, like the other 16.

In another embodiment, the frame 20 can be welded to the end portions 30 and 34 by welding in advance. In this method, it is necessary to increase the rigidity of the frame 20 used in the above method. The reason is that such a rectangle is easily deformed by a tensile force. When the concrete is poured as in the present invention, by forming the reinforcing bar 22 integrally, there is an advantage that the force does not need to be applied to the frame 20. After the concrete has hardened, the tensile force on the frame 20 is dispersed also in the concrete, and the deformation of the frame 20 is small.

The step (D) may be performed before the step (C). In this case, the number of rebars that can be divided is increased. Otherwise, the frame 20 may be distorted. Also, the end portions 30, 34 of the splittable rebar 22
May be increased by changing the rigidity with the central portion 32. The reason is that the central portion 32 is eventually removed.

[0015]

As described above, in the prestressed concrete pole of the present invention, even if an opening is formed in the side direction, the reinforcing bar 22 at the opening is formed by the frame 20.
, The strength stability of the concrete pole can be secured, and the concrete pole can be prevented from bending.

[Brief description of the drawings]

FIG. 1 is a diagram showing an entire concrete pole to which the present invention is applied.

FIG. 2 is a view showing the vicinity of an opening of a conventional concrete pole; the left figure is a front view thereof; and the right figure is a cross-sectional view cut along AA.

FIG. 3 is a view showing the vicinity of an opening of a concrete pole of the present invention, wherein the left figure is a front view thereof, and the right figure is a cross-sectional view cut along AA.

FIG. 4 is a partial view showing a final form of the concrete pole of the present invention, wherein the upper figure is a front view and the lower figure is a partial bottom view.

FIG. 5 is a perspective view of a side opening frame according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Concrete pole of this invention 12 Lighting 14 Side surface 16 Reinforcing bar 18 Halfway rebar 19 Frame 20 Frame of the present invention 22 Reinforcing bar 24 Fixing nut 30 End part 32 Central part 34 End part 36 Joint nut

Claims (7)

(57) [Claims] A plurality of rebars (16, 22) are provided inside the concrete wall, and the periphery thereof is provided on the side thereof with a frame (2, 22).
In the prestressed concrete pole having an opening formed in the above (0), the reinforcing bars (16, 22) and the frame (20) are connected to the frame (2).
0), the end portion (3) of the reinforcing bar (22) penetrating the hole formed in the hole (3).
A concrete pole having a side opening, characterized in that it is connected via a fixing nut (24) which is screwed into a screw cut at 0, 34). 2. (A) A frame (20) and this frame (20)
(B) arranging a plurality of reinforcing bars (16) on the column section except for the location of (b), the center portion (32) being placed in the frame (20) through the frame (20), Arranging the splittable rebar (22) such that most of the portions (30, 34) are outside the frame (20); and (C) applying a pulling force to the rebar (16, 22); The structure (16,
(20, 22), injecting concrete and centrifugally casting; and (D) removing the central portion (32) in the frame (20) of the concrete pole formed by the above step. A method for producing a concrete pole having a side opening. 3. The method of claim 2, further comprising the step of: (E) securing said end portions (30, 34) to a frame (20). 4. The splittable rebar (22) comprises a first end portion (30), a central portion (32), and a second end portion (34), wherein the first end portion Connection of the part (30) with the central part (32) and the central part (32) and the second end part (34)
Is connected via a joint nut (36) which is screwed into a screw formed at the first and second end portions, and is connected to the first and second end portions (30, 34). 3. The method according to claim 2, wherein the frame is engaged with the frame by an engaged locking nut. 5. The method of claim 4, wherein in the step (D), a central portion (32) of the splittable rebar (22) is removed by removing a joint nut (36). 6. The method of claim 2, wherein the end portions (30, 34) of the splittable rebar (22) are more rigid than the central portion (32). 7. The method of claim 3 wherein said step (E) is further performed by a locking nut (24) engaged with said end portions (30, 34).