JPH07253189A - Corrosion preventive cap for pipe end face - Google Patents

Abstract

PURPOSE:To let the corrosion preventive cap surely exhibit corrosion preventive function by integrally forming a cylindrical inner circumferential section to be inserted in the inner circumference of a pipe, a flange section closely in contact with the end face of the pipe, and a cylindrical outer circumferential section covering the outer circumference of the end of the pipe. CONSTITUTION:When the corrosion preventive cap 20 is attached to the end section of a pipe 11, a cap main body 22 is fitted in the end section of the pipe 11 in such a way that a space between a cylindrical inner circumferential section 24 and a cylindrical outer circumferential section 25 is parted from each other. In this case, since the outer diameter of the cylindrical inner circumferential section 24 at its tip end side is larger than the inner diameter of the pipe 11, the cylindrical inner circumferential section 24 is elastically deformed in the direction of diameter contraction, so that its outer circumferential surface 27 is inserted in such a manner as to be closely in contact with the inner circumferential surface of the pipe 11. Besides, since a flange section 23 is fitted therein in such a manner as to be pushed on the end face 11a of the pipe 11, the flange section 23 is closely in contact with the end face 11a of the pipe 11. In this case, since an outer circumferential surface at the end section of the pipe 11 is also covered by the cylindrical outer circumferential, section 25, corrosion preventive function can thereby be assured much more.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pipe end face anticorrosion cap.

[0002]

2. Description of the Related Art When laying a pipeline, the purpose is to adjust the length of the pipe to a suitable length according to the conditions of the laying site.
It may be necessary to cut the tip of this tube. When such a cut tube is performed, since the ground surface is exposed at the end surface of the tube that is the cut end, it has been proposed to use an anticorrosion cap that closely adheres to and seals this ground surface from the viewpoint of corrosion protection. There is.

As shown in FIG. 4, the anticorrosion cap 1 has a cap body 2 which is attached to the end of the cut tube 3 when it is attached to the end of the tube 3. The tubular portion 4 inserted into the inner periphery and the flange portion 5 formed on the outer periphery of one end of the tubular portion 4 are integrally formed of an elastic body such as rubber. The tubular portion 4 is formed in a tapered shape so as to open outward as it goes away from the flange portion 5, and an annular packing 6 made of a soft rubber plate or the like is in contact with the flange portion 5 on the tubular portion 4. The annular packing 6 is intended to come into close contact with this end face 3a in the compressed state by being externally fitted in the state and pressing the flange portion 5 against the end face 3a of the pipe 3.

[0004]

However, in the anticorrosion cap 1 having such a conventional structure, since the outer peripheral portion a of the boundary portion between the end surface 3a of the pipe 3 and the annular packing 6 is exposed to the outside, it flows in the pipe. There is a possibility that the fluid or the like may enter from the boundary end portion a and fail to reliably exhibit the anticorrosion function.

The present invention solves the above problems, and an object of the present invention is to provide an anticorrosion cap capable of reliably exhibiting an anticorrosion function.

[0006]

To achieve this object, a pipe end face anticorrosion cap according to the present invention is in close contact with a tubular inner peripheral portion inserted into the inner periphery of the end portion of the pipe and the end face of the pipe. The flange portion and the tubular outer peripheral portion that covers the outer periphery of the end portion of the tube are integrally formed.

[0007]

With the above structure, the outer periphery of the end of the pipe is covered with the cylindrical outer periphery, so that the fluid is prevented from entering the boundary between the end face of the pipe and the flange, and the anticorrosion function is reliably exhibited. Will be done.

[0008]

Embodiments of the present invention will be described below with reference to the drawings. In FIG. 2, reference numeral 10 denotes a joint ring for connecting the cut pipes 11 to each other, and at a position farther to the inner side than each opening end of the joint ring 10, a diameter slightly larger than the outer diameter of the pipe 11. Large-diameter holes 12 are formed respectively, and these holes 1
2, the ends of the cut tubes 11 are inserted into the respective tubes. An annular groove 13 is formed on the inner periphery of the joint ring 10 on the far side from the open end, and the annular groove 13 is formed in the annular groove 13.
An annular seal material 14 that is compressed between itself and the outer circumference of the end of the is accommodated.

A flange 15 is formed on the outer circumference of each open end of the joint ring 10, and insertion holes 16 are provided in the flange 15 at a plurality of positions in the circumferential direction in the pipe axis direction. Then, the push wheel 17 is externally fitted to the end of the pipe 11, and the screw portion side is fastened to the flange 15 with the bolt 18 passing through the insertion hole 16, whereby the push wheel 17 seals the seal material 1.
4 is compressed to prevent fluid leakage from the inside of the joint ring 10.

The pipe 11 is made of ductile cast iron or the like, and its inner and outer surfaces are anticorrosion coated.
One end of this pipe 11 is cut as described above at a laying site so as to have a predetermined length, and the end surface 11a formed by this cut pipe has an exposed bare surface.

In order to prevent erosion from the end surface 11a of the pipe 11, an anticorrosion cap 20 as shown in FIGS. 1 and 3 is attached to the end of the cut pipe 11. The anticorrosion cap 20 has a cap body 22, and the cap body 22 is provided with a ring-shaped flange portion 23 that is brought into close contact with the end surface 11 a of the pipe 11 and extends one side from the inner peripheral end portion of the flange portion 23. The cylindrical inner peripheral portion 24 that is inserted into the inner periphery of the end of the pipe 11 and the cylindrical outer periphery that extends one side from the outer peripheral end of the flange 23 and covers the outer periphery of the end of the pipe 11. Part 25
And are integrally formed of an elastic body such as rubber.

The cylindrical inner peripheral portion 24 is formed in a tapered shape so as to open outward as the distance from the flange portion 23 increases, and a corresponding tapered inner peripheral surface 26 and a tapered outer peripheral surface 27 are formed. Have. The outer peripheral surface 27 of the cylindrical inner peripheral portion 24 has an outer diameter on the flange portion 23 side,
It is formed to be slightly smaller than the inner diameter of 1 and larger than the inner diameter of the tube 11 at the end opposite to the flange 23. On the inner peripheral surface 26 of the cylindrical inner peripheral portion 24, an annular groove 28 having a rectangular cross section is formed at a position spaced from the flange portion 23 in the axial direction. A stopper ring 29, which is freely formed by a metal spring material in the shape of an annular flat strip divided in the circumferential direction, is fitted.

Further, the cylindrical outer peripheral portion 25 is formed in a taper shape so as to become a slight inner recess as it goes away from the flange portion 23, and at the end portion on the side opposite to the flange portion 23, the outer diameter of the pipe 11 is smaller than the outer diameter of the pipe 11. It is formed to be a little smaller. In addition, a taper surface 30 is formed at an outer peripheral portion of a connection portion between the flange portion 23 and the cylindrical outer peripheral portion 25 so as to gradually taper away from the end surface 11a of the pipe 11, and the end portion of the pipe 11 is joined. When being inserted into the hole portion 12 of 10, the taper surface 30 guides it.

In the above structure, when the cut pipes 11 are connected to each other by the joint ring 10, the anticorrosion cap 20 is attached to the end portion of the pipe 11 prior to the connecting work.

When mounting the anticorrosion cap 20 on the end portion of the pipe 11, first, as shown in FIG. 3, the cap main body 22 is placed between the cylindrical inner peripheral portion 24 and the cylindrical outer peripheral portion 25. Fit into the ends of the tube 11 so that they spread over each other.
At this time, since the outer diameter of the cylindrical inner peripheral portion 24 on the tip side is larger than the inner diameter of the pipe 11, the cylindrical inner peripheral portion 24 is elastically deformed in the diameter reducing direction, and the inner peripheral surface 27 of the pipe 11 It is inserted in close contact with the peripheral surface. Further, since the inner diameter on the tip side of the tubular outer peripheral portion 25 is smaller than the outer diameter of the pipe 11, the tubular outer peripheral portion 25 is elastically deformed in the radial expansion direction and is attached in a state of being in close contact with the outer peripheral surface of the pipe 11. To be done. Also, by mounting the flange portion 23 so as to press it against the end surface 11a of the pipe 11,
The flange portion 23 is in close contact with the end surface 11a of the pipe 11.

After that, the stopper ring 29 is manually reduced in diameter and fitted into the annular groove 28, so that the cylindrical inner peripheral portion 24 is moved to the pipe 1 by the expanding force of the stopper ring 29.
It is pressed and fixed to the inner peripheral surface of 1.

When connecting the ends of the pipes 11 with the anticorrosion caps 20 attached thereto through the joint ring 10, the push ring 17 and the sealing material 14 are fitted onto the ends of the pipes 11 in advance. After that, the ends of the pipes 11 are inserted into the holes 12 of the joint ring 10 after this. At this time, since the taper surface 30 is formed at the outer peripheral portion of the connecting portion between the flange portion 23 and the cylindrical outer peripheral portion 25, the end portion of the pipe 11 has the taper surface 30.
The guide is guided into the hole 12 of the joint ring 10 to facilitate the insertion work. And finally, the sealing material 14
With the bolt inserted into the annular groove 13 of the joint ring 10,
By fastening the push ring 17 to the flange 15 of the joint ring 10 by means of 8, the leakage of fluid from the inside of the joint ring 10 is prevented by the compressed sealing material 14.

In this case, since the pipes 11 are not directly connected to each other, the fluid in the pipes 11 flows into the joint ring 10, but the end surface 11a of the pipe 11 where the background is exposed. Since it is covered with the anticorrosion cap 20, the fluid is prevented from entering the end surface 11a of the pipe 11. In particular, not only the end surface 11a and the inner peripheral surface of the end of the pipe 11 are covered with the anticorrosion cap 20, but also the outer peripheral surface of the end of the pipe 11 is covered by the cylindrical outer peripheral portion 25, so that the anticorrosive function is provided. It can be obtained more reliably.

In the above embodiment, the case where the end of the pipe 11 covered with the anticorrosion cap 20 is connected to the joint ring 10 has been described, but the present invention is not limited to this, and the anticorrosion cap 20 is used. It goes without saying that it may be adopted for various joints such as a socket as long as the end of the covered pipe 11 can be inserted and connected without any trouble. Further, in the above embodiment, the cylindrical outer peripheral portion 25 of the cap body 22 is
3 shows a case where the taper is formed so as to be slightly recessed inward as it goes away from the flange portion 23, but it may have a shape that extends perpendicularly to the flange portion 23. It is sufficient that the cylindrical outer peripheral portion 25 follows the outer peripheral surface of the end portion of the pipe 11 when mounted on the end portion of the pipe 11.

[0020]

As described above, according to the present invention, since the tubular outer peripheral portion that covers the outer periphery of the end portion of the pipe is formed in the anticorrosion cap, it is only necessary to cover the end surface of the pipe and the inner peripheral surface of the end portion by the anticorrosion cap. The tubular outer peripheral portion of the anticorrosion cap can also cover the outer peripheral surface of the end portion of the pipe, and as a result, it is possible to reliably prevent the fluid in the pipe from contacting the end surface of the pipe, and further improve the anticorrosion function. it can. Further, as a result, it is possible to omit the annular packing and the like, which have been conventionally required, so that it is possible to reduce the number of parts and eventually the cost.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a mounted state of an anticorrosion cap on a pipe end surface according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view showing a case where a pipe provided with the anticorrosion cap is connected to a joint ring.

FIG. 3 is a cross-sectional view illustrating a procedure for mounting the anticorrosion cap.

FIG. 4 is a cross-sectional view showing a mounted state of a conventional anticorrosion cap.

[Explanation of symbols]

 10 joint ring 11 pipe 11a end face 20 anticorrosion cap 22 cap body 23 flange part 24 cylindrical inner peripheral part 25 cylindrical outer peripheral part 28 annular groove 29 stopper ring 30 taper surface

Claims (1)

[Claims] 1. A tubular inner peripheral portion that is inserted into the inner periphery of the end portion of the pipe, a flange portion that is in close contact with the end surface of the pipe, and a tubular outer peripheral portion that covers the outer periphery of the end portion of the pipe. An anti-corrosion cap for the pipe end face, which is formed integrally.