JPH08270884A - Coat pressurizing device - Google Patents

Abstract

PURPOSE: To simply eliminate an air void, caused when a heat shrinkage tube is coated on a pipe body, and to make proper corrosion protective coating easily formable by integrally forming a side frame with a guide part in both the ends of the guide part, and forming the side frame into an annular state having an inner diameter larger than the outer diameter of a pipe body. CONSTITUTION: At first, a pipe body (p), coated with a heat shrinkage tube, is supported by a supporting device, and the lower side half of a halved side frame 4 is arranged in the lower side of the pipe body (p); and then the upper side side frame is placed on the pipe body (p) so as to cover the pipe body (p) from an upper part, and also both the side frames are joined at a joining part 4b. Then, the position of a roller 2 is adjusted to the outer diameter and pressurizing position of the pipe body (p). After adjustment, pressure can be applied to the heat shrinkage tube via the roller 2 by rotating the frame 4 via handles 5 to surely eliminate an air void between the pipe body (p) and the heat shrinkage tube.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a gas pipe, a water pipe,
The present invention relates to a coating pressurizing device used to eliminate a gap called an air void that occurs when a heat-shrinkable tube for corrosion protection is coated on a joint portion of a pipe body such as an electric power pipe.

[0002]

2. Description of the Related Art Generally, steel pipes used for gas pipes, water pipes, electric power pipes, etc. are coated with a synthetic resin material such as polyethylene at a manufacturing plant to prevent corrosion. Since it is welded, the end of the pipe body is not coated with anticorrosion, and it is necessary to perform anticorrosion coating each time at the piping site.

As a method of this anticorrosion coating,
A heat-shrinkable tube made of heat-shrinkable synthetic resin material such as cross-linked polyethylene is covered, and the heat-shrinkable tube is shrunk and covered by manual heating with a burner or by automatic heating with far-infrared irradiation. There is also a method in which a heating wire is built in the heat shrink tube in advance, and the heat shrink tube is shrunk and covered by heating the wire by energizing the heating wire to generate heat.

In the joint portion covering the heat shrinkable tube, there is a step between the steel pipe p and the weld bead portion a and between the steel pipe surface and the factory covering portion b as shown in FIG. When c is coated on the joint portion, the heat-shrinkable tube c comes into contact with the industrial coating portion b, the weld bead portion a, and the steel pipe surface, but at the step portion, the heat shrinkable tube c cannot contact the steel pipe surface and a gap called an air void d is formed.

In order to prevent this, even if a sheet or the like is wound around the step portion in advance, a new step portion may occur between the wound portion and the unwound portion of the sheet.

Further, even in a portion having no step, an air void may be generated between the heat shrinkable tube and the surface of the steel pipe and the sheet by containing air.

As a method of eliminating such an air void, conventionally, after coating a heat shrinkable tube, a roller is manually applied. However, roller installation cannot be performed in a narrow installation place where there is no working space, such as an open groove and a common groove. Further, even if there is a working space, there is a problem that sufficient pressing force cannot be applied to the roller at the lower side of the joint or the like.

Further, even if a sufficient pressure can be applied to the roller, it may be insufficient to eliminate the air void by manual pressure, and it is extremely difficult to completely eliminate the air void. Met.

[0009]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and easily eliminates air voids generated when a heat shrinkable tube is coated on a tubular body, thereby providing good corrosion protection. An object of the present invention is to provide a coating pressurizing device that can easily form a coating.

[0010]

According to the first aspect of the present invention,
A heat-shrinkable tube covering a tubular body is pressed from the outside to bring the heat-shrinkable tube into contact with the tubular body, and a roller for pressurizing the heat-shrinkable tube from the outside and a roller for supporting the roller. And a side frame formed integrally with the guide part at both ends of the guide part and formed in an annular shape having an inner diameter larger than the outer diameter of the tubular body.

[0011]

According to the first aspect of the present invention, the guide portion and the rollers supported by the side frames at both ends of the guide portion are provided. By rotating the side frame, pressure is applied to the entire outer peripheral wall of the tubular body. Can be easily implemented. Further, the pressing force of the roller can be controlled by an air cylinder type pressing device or a spring type pressing device. Therefore, it is possible to surely eliminate the air void between the tube body and the heat-shrinkable tube by the pressurizing operation, and it is possible to perform the pressurizing operation accurately even in a narrow place where the roller cannot be manually applied. Further, even after cooling the heat-shrinkable tube, the air voids can be eliminated by applying sufficient pressure.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the coating pressurizing device according to the present invention will be described in detail below with reference to the accompanying drawings.

FIG. 1 is a perspective view showing a state where a coating pressurizing device according to an embodiment of the present invention is mounted on a joint portion of a steel pipe, and FIG. 2 is a side view of the device.

The coating pressurizing device 1 is a device for pressurizing the heat-shrinkable tube c covering the pipe body p from the outside so as to bring the pipe body p and the heat-shrinkable tube c into close contact with each other.
A pressing portion 6 for pressing the roller 2 against the heat-shrinkable tube c, a guide portion 3 for supporting the roller 2, and a guide portion 3 formed integrally with the tubular body p.
The side frame 4 is formed in an annular shape having an inner diameter larger than the outer diameter of the side frame 4.

The pressure unit 6 shown in FIG. 1 is an air cylinder type, and the pressure unit 6'shown in FIG. 3 is a spring type.

In this embodiment, four rollers are arranged around the tube body p at positions where the circumference of the tube body p is divided into four equal parts. This roller is supported by the guide portion 3, as shown in FIG.

The guide portion 3 has a shaft 3e which penetrates the shaft hole of the roller 2 and a frame 3d which supports the shaft 3e.
And two guide shafts 3a standing on the outer peripheral surface 3d 'of the frame 3d, and a cylindrical guide tube 3b integrally formed with the guide plate 3c. Two guide shafts 3
The letter a passes through a guide hole 3f formed in the guide tube 3b and is slidably supported. Furthermore, the guide plate 3c
The shaft 6'b of the pressure unit 6'abuts on the outer peripheral surface 3d 'of the frame 3d, and the main body 6d' of the pressure unit 6'is fixed to the guide plate 3c.
Both ends of the guide plate 3c are the brackets 4 of the side frame 4.
a and a bolt 11 are connected.

The pressure unit 6'shown in FIG. 3 is of a spring type and has a shaft 6'b integrated with a spring 6'c.
The outer peripheral surface 3d 'of the roller frame 3d is
, So that the roller 2 presses the heat-shrinkable tube c on the surface of the tubular body. This pressure unit 6 '
The adjustment of the pressing force by is performed by adjusting the elastic force of the spring 6'c by the pressing force adjusting handle 6'a. The roller 2 is configured to be movable in the radial direction of the tube body p in consideration of the case where the diameter of the tube body p changes.

On the other hand, the pressurizing section 6 shown in FIGS. 1 and 2 is an air cylinder type, and an air hose 9 communicating with a compressed air source (not shown) and a compressed air from the compressed air source move the piston of the air cylinder. An air control unit 8 is provided.

As shown in FIGS. 1 and 2, the side frames 4 are formed as a pair of annular flat plates and are arranged at both ends of the guide plate 3c of the guide portion 3, respectively. The side frame 4 needs to be arranged outside the pipe body p.
The inner diameter of is larger than the outer diameter of the tube body p.
To facilitate mounting of the side frame 4 on the pipe body p,
The side frame 4 can be divided into two with the joint portion 4b as a boundary.

A handle 5 is provided between the pair of side frames 4 at a predetermined interval. Both ends of the handle 5 are supported by opposite side surfaces of the side frame 4. Further, the pedestal 10 can support the coating pressurizing device 1.

Next, a procedure for eliminating the air voids generated when the heat-shrinkable tube c is coated on the pipe body p by using the coating pressurizing apparatus according to the present invention will be described. First, the tubular body p covering the heat-shrinkable tube c is supported by a support device (not shown), and the lower half of the side frame 4 divided into two is arranged below the tubular body p. Next, the upper side frame 4 is placed on the pipe body P so as to cover the pipe body p from above, and both side frames 4 are joined at the joint portion 4b.

After that, the position of the roller 2 is adjusted according to the outer diameter of the pipe p and the pressure position. At this time, the roller 2
The axial movement of the tubular body p of the
The movement of the roller 2 in the radial direction of the tube body p is performed, for example, by adjusting the stroke of the air cylinder of the pressure unit 6.

The pressurizing force of the roller 2 is adjusted by adjusting the compressed air pressure by the air control unit when the pressurizing unit 6 is of the air cylinder type, and is shown in FIG. 3 when it is of the spring type. This can be done by adjusting the elastic force of the spring 6'c via the handle 6'a.

After the above adjustment, the side frame 4 is attached to the handle 5
By rotating the heat-shrinkable tube c through the roller 2, pressure is applied to the heat-shrinkable tube c via the roller 2, and the air void between the tube body p and the heat-shrinkable tube c is reliably eliminated. At this time, the side frame 4 has four rollers 2 at symmetrical positions.
Is arranged, the coating pressurizing device 1 is
By rotating about the circumference, the entire circumference of the heat-shrinkable tube can be pressed by the roller 2, and the tube body p and the heat-shrinkable tube c can be pressed.
Air voids between and are reliably eliminated

An example in which the test materials 1 to 6 shown below are tested by using the coating pressurizing apparatus according to the present invention will be described.

The test material 1 is a heat-shrinkable tube made of cross-linked polyethylene (the thickness of the cross-linked polyethylene is 1.5 mm and the thickness of the adhesive is 1 m) at the joint portion where the 750 A steel pipes are welded to each other.
m) was coated and heated by hand to shrink it.

The test material 2 was prepared under the same conditions as the test material 1 except that the pressure-sensitive adhesive sheet was previously wound around the step formed in the joint.

The test material 3 was prepared by covering the joint portion where 750A steel pipes were welded with each other with the heat-shrinkable tube used when the test material 1 was manufactured, and shrinking it by far-infrared heating.

The test material 4 was prepared under the same conditions as the test material 1 except that the pressure-sensitive adhesive sheet was previously wound around the step formed in the joint.

The test material 5 was obtained by coating the joint portion of 750A steel pipes welded with each other with the heat-shrinkable tube used when the test material 1 was manufactured, and incorporating a heating wire in the heat-shrinkable tube. It was manufactured by shrinking by heat generation by energization.

The test material 6 was prepared under the same conditions as the test material 1 except that the pressure-sensitive adhesive sheet was previously wound around the step formed in the joint portion.

Using the test material, pressure was applied at 3 kgf / cm using a coating pressurizing device, and the presence or absence of air voids generated between the steel pipe and the heat-shrinkable tube was measured. On the other hand, using the same test material as above, after shrinking the heat-shrinkable tube, as a comparative example, manually roller-rolled, and measured for the presence or absence of air voids generated between the steel tube and the heat-shrinkable tube, The results shown in Table 1 were obtained.

[0034]

[Table 1]

As shown in Table 1, in the case of the manual work shown as the comparative example, the diameter is 10
While 1 to 3 air voids of mm or more were found, no air voids were found in any of Examples 1 to 6 when the coating pressurizing device according to the present invention was used. In addition, the work with the coating pressurizing device can be performed in about 5 minutes to pressurize the 600 mm width, including the removal of the device, and the work time is significantly shorter than the time required for roller application. Could be done in.

[0036]

According to the first aspect of the present invention, since the roller surrounding the outer peripheral wall of the tubular body is provided, it is possible to accurately and simply pressurize the entire outer peripheral wall of the tubular body. The air void between the heat-shrinkable tube and the heat-shrinkable tube is surely eliminated, and the pressurizing operation can be performed even in a narrow place where manual roller hanging cannot be performed, which greatly improves workability and reliability. There are advantages.

[Brief description of drawings]

FIG. 1 is a perspective view of an embodiment of a coating pressurizing device according to the present invention.

2 is a side view of the coating pressure device of FIG. 1. FIG.

FIG. 3 is a detailed view of a pressurizing unit of the coating pressurizing device according to the present invention.

FIG. 4 is an explanatory diagram showing air voids generated between a tubular body and a heat-shrinkable tube.

[Explanation of symbols]

 1 coating pressurizing device 2 roller 3 guide part 3a guide shaft 3b guide cylinder 3c guide plate 3d frame 3e shaft 3f guide hole 4 side frame 4a bracket 4b connecting part 5 handle 6 pressurizing unit 6'pressurizing unit 6'a pressurizing force Adjustment handle 6'b Shaft 6'c Spring 6'd Main body 8 Air control unit 9 Air hose p Tube c Heat shrink tube

 ─────────────────────────────────────────────────── ─── Continued Front Page (72) Inventor Tadashi Kawamura 1-2-1, Marunouchi, Chiyoda-ku, Tokyo Nihon Steel Pipe Co., Ltd.

Claims (1)

[Claims] 1. A coating pressurizing device for pressurizing a heat-shrinkable tube covering a tubular body from the outside to bring the tubular body and the heat-shrinkable tube into close contact with each other, and a roller for pressurizing the heat-shrinkable tube from the outside. A guide portion for supporting the roller, and a side frame formed integrally with the guide portion at both ends of the guide portion and formed in an annular shape having an inner diameter larger than the outer diameter of the tubular body. A coating pressurizing device.