JP3501980B2 - Heat shrink sleeve shrink device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat shrink sleeve shrinking device and a heat shrink sleeve shrinking method using this device. In particular, the present invention relates to an optimal device for heating a heat-shrinkable sleeve that covers a boundary between a fixed length portion and a free length portion in an anchor structure using unbonded PC steel.

[0002]

2. Description of the Related Art As a means for preventing collapse of rocks and slopes,
The anchor structure shown in FIG. 5 is known. This is the slope
It comprises an anchor head exposed from 13 and an anchor body 15 embedded in the slope. Anchor hole on slope 13
16 is formed, and the unbonded PC steel strand 17 is inserted into this anchor hole 16.

A concrete example of the unbonded PC steel strand 17 is shown in FIGS. The unbonded PC steel stranded wire in FIG.
A core material 10 is formed by twisting 18 together, and a jacket 9 made of polyethylene or the like that does not adhere to the core material 10 is formed on the outer periphery of the core material 10, and a protective material 19 such as grease is filled between the core material 10 and the jacket 9. It is a thing. In addition, FIG. 7 (A) shows the core material 10 and the jacket 9 alone without any anticorrosion material, FIG. 7 (B) shows the core material with an anticorrosion layer 20 such as epoxy resin, and FIG. 7 (C) shows Strand
Each of the 18 is provided with an anticorrosion layer 20 such as an epoxy resin and then twisted to form a jacket.

Such an unbonded PC steel stranded wire 17 is
Free length 25 with the jacket 9 left and fixed length with the jacket 9 removed
It is divided into 26 (Fig. 5). Grout in the anchor hole
27 is injected, but the envelope 9 of the free length 25 cuts the edges of the core 10 and the grout 27. Further, the fixing long portion 26 is integrated with the surrounding grout 27 to form the anchor body portion 15. Therefore, if the core material 10 is tensioned and fixed by the anchor head portion 14, a tightening force can be obtained between the anchor head portion 14 and the anchor body portion 15.

By the way, at the boundary between the free length portion and the fixed length portion, it is possible to prevent the grout from flowing into the envelope of the free length portion during pouring of the grout, and to prevent the infiltration of water after the anchor construction. It is necessary to stop the water surely in order to remove it. Conventionally,
To form the water blocking portion, tape winding or resin coating is performed. As a more reliable method, it is considered to cover with a heat shrinkable sleeve for heating / shrinking.
Generally, heating of the heat-shrinkable sleeve 7 includes a method using a fire heating device such as a gas burner and a method using hot air from a dryer 30 as shown in FIG.

[0006]

However, the above heat-shrinkable sleeve heating technique has the following problems. In the method using a burner, the heating temperature is too high, which not only adversely affects the outer coating such as polyethylene that forms the free length and the anticorrosion layer such as epoxy resin, but also damages the mechanical properties of the strand of PC steel stranded wire. There is a nature.

[0007] In the method using a dryer, it is difficult for hot air to reach the heat shrinkable sleeve, especially when the outside air temperature is low or the wind is strong, and it takes too long to heat.

In any of the methods, in order to heat the entire circumference of the heat shrink sleeve, it is necessary to rotate the burner or the dryer on the outer circumference of the heat shrink sleeve, and there is a difficulty in workability.

In either method, the heat shrink sleeve is likely to have uneven shrinkage depending on the skill level of the operator, and the stability of the water stopping performance is insufficient.

Therefore, a main object of the present invention is to provide a shrinking apparatus and a shrinking method capable of heating a heat shrinkable sleeve easily and in a short time without uneven shrinkage.

[0011]

The present invention achieves the above object by utilizing a heating portion that surrounds the entire length and circumference of the heat shrink sleeve.

That is, the apparatus of the present invention is characterized in that it is provided with a heating section having a concave cross section which is configured to be openable and closable and covers the entire length and circumference of the heat shrink sleeve.

Here, examples of the heating section having a concave cross section include those having a semi-cylindrical shape and a semi-square shape. Since the heat-shrinkable sleeve is generally cylindrical, the semi-cylindrical shape of the heating section makes it possible to unify the distance from the inner surface of the heating section to the heat-shrinkable tube, and to facilitate uniform shrinkage. Specific examples of the heating unit include a heater and an infrared lamp. At both ends of the heating part,
It is desirable to have a gripping part that maintains a gap between the outer surface of the object to be coated and the inner surface of the heating part. A heat insulating material is suitable for the material of the grip portion. By the gripping part coming into contact with the coating target,
It is possible to prevent the coating target itself from melting. Further, at both ends of the heating part, a shielding part may be provided which closes the gap between the outer surface to be covered and the inner surface of the heating part over the entire circumference. With such a shielding part, the airtightness of the space surrounded by the heating part is improved,
The heating time can be shortened. Further, it is preferable that an arcuate member having a different diameter is detachably attached to the inner circumference of the grip portion so that the inner diameter of the grip portion can correspond to the covering target having a different outer diameter.

Further, the shrinking method of the heat shrinkable sleeve of the present invention comprises a step of covering the outer periphery of the object to be coated with the heat shrinkable sleeve,
The present invention is characterized by including a step of covering the entire length and the entire circumference of the heat shrink sleeve with a heating section having a concave cross section configured to be openable and closable, and a step of heating and shrinking the heat shrink sleeve by the heating section.

The object of coating may be the boundary between the free length portion and the fixed length portion in the unbonded PC steel material.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below. FIG. 1 shows the device of the present invention, (A) is a front view, (B)
Is a side view.

As shown in FIG. 1, the device of the present invention is a T-shaped clothespin. A semi-cylindrical heating unit 1 is openably and closably opposed to each other, and when both heating units 1 are closed, a space between the heating units 1 is a cylindrical space that covers the entire length and circumference of the heat shrink sleeve.
2 is formed. A heater and an infrared lamp are uniformly arranged on the inner surface of the heating unit so that the space 2 can be heated uniformly. Each heating unit 1 is configured so that the temperature can be adjusted.

Further, a handle 3 is integrated in a direction orthogonal to the central portion of each heating portion 1. The heating part 1 is opened by closing the handle 3, and the heating part is closed by opening the handle 3. That is, tongues 4 are provided so as to project from the center of the handle 3 in directions opposite to each other, and a support shaft that penetrates these tongues 4
Both handles 3 are rotatably connected by 5.

Further, as shown in FIG. 2, gripping portions 6 are formed at both ends of each heating portion 1. The grip 6 is the heating unit 1
A space is maintained between the coating target and the coating target to prevent the coating target from being melted by the heat of the heating unit 1. Therefore, the inner diameter of the grip portion 6 corresponds to the outer diameter of the coating target. In this example, since the boundary between the free length portion 25 and the fixed length portion 26 in the anchor structure is covered, the inner diameter of the one gripping portion 6 corresponds to the outer diameter of the outer sheath of the unbonded PC steel stranded wire, and the other The inner diameter of the gripping 6 part corresponds to the outer diameter of the core material of the same stranded wire. Further, in this example, as shown in FIG. 3 (A), the grip portion 6 is provided at a position that divides the inner circumference of the heating portion into four equal parts, but if the space can be maintained between the heating portion 1 and the coating target, the grip portion will be The number of 6 is not particularly limited. It is preferable to dispose a heat insulating material on at least the inner peripheral surface of the grip portion 6. Since the inner diameter of the grip portion 6 corresponds to the outer diameter of the target to be coated, it is conceivable that the heat of the heating portion will be transferred to the target to be coated via the grip portion 6 and melted without the heat insulating material. If a heat insulating material is used for the grip portion 6, it is possible to prevent the object to be coated from being melted even if it is easily melted, such as the jacket (normally polyethylene) in this example. A known material such as asbestos may be used as the heat insulating material.

Since it is necessary to change the inner diameter of the grip portion 6 when the outer diameter of the object to be coated is different, it is desirable to use a detachable arc-shaped member (not shown) on the inner circumference of the grip portion. The arcuate member is a trapezoidal block composed of partial arcs of which two opposite sides in a cross section are concentric circles. If plural kinds of arcuate members having different diameters of the partial arcs are prepared, coatings of various sizes are provided. The inner diameter of the grip portion 6 can correspond to the target.

Further, as shown in FIG. 2, a shielding portion 8 is provided axially outside the grip portion 6 of the heating portion 1. As shown in FIG. 3 (B), the shielding portion 8 closes the gap between the outer surface of the coating object and the inner surface of the heating portion over the entire circumference, thereby preventing the heat of the heating portion 1 from escaping from both ends. . As a result, the airtightness of the space 2 surrounded by the heating unit 1 is improved, heat is prevented from leaking to the outside, and heat shrinkage can be performed in a shorter time. The material of the shielding portion 8 is preferably one that is not easily deformed by heat, and rubber or the like can be used. In this example, the grip 6 and the shield 8 are separately provided, but instead of omitting the grip 6 in FIG.
If it is made of a heat insulating material, it can also serve as a shield and a grip.

The procedure for using such a contraction device will be described with reference to FIG. First, the free length part in the anchor structure
The heat-shrink sleeve 7 is fitted on the outer periphery of the boundary between the fixing portion 25 and the fixing long portion 26 (FIG. 4A). The heat-shrinkable sleeve 7 is formed by coating a hot melt adhesive on the inner surface of a cylindrical base material containing polyethylene, PVC, EVA or the like as a main component. next,
Hold down the handle 3 to open the heating unit 1, and cover the entire length and circumference of the heat shrink sleeve with the heating unit 1 (Fig. 4B). Then, the heat-shrink sleeve 7 is heated to shrink, and the shrink device is removed (FIG. 4C).

[0023]

As described above, according to the shrinking device and method of the present invention, it is necessary to rotate the shrinking device around the heat shrinking sleeve by heating the shrinking sleeve with the heating portion surrounding the entire length and circumference of the shrinking sleeve. As a result, the heat shrink sleeve can be uniformly shrunk in a short time.

Further, by providing a gripping portion at both ends of the heating portion for holding a space between the outer surface of the coating object and the inner surface of the heating portion, it is possible to prevent the coating object from melting. In particular, by disposing a heat insulating material in the grip portion, this effect can be further enhanced.

Further, by providing a shield part at both ends of the heating part, which closes the space between the outer surface of the object to be coated and the inner surface of the heating part over the entire circumference, the hermeticity of the space surrounded by the heating part is enhanced, and the time is further shortened. Allows contraction of.

Therefore, the apparatus and method of the present invention are optimal for covering the boundary between the free length portion and the fixed length portion in unbonded PC steel.

[Brief description of drawings]

1 shows a shrinking device of the present invention, (A) is a front view, (B)
Is a side view.

FIG. 2 is a vertical sectional view showing a state during heating by the device of the present invention.

3A is a sectional view taken along the line AA in FIG. 2, and FIG. 3B is a sectional view taken along the line BB.

FIG. 4 shows a procedure for using the shrinking device of the present invention, (A) is a front view of a state in which a heat shrinking sleeve is fitted on a target to be coated,
(B) is a front view showing a state in which the heat shrink sleeve is heated by the device of the present invention, and (C) is a front view showing a covering object after shrinking the heat shrink sleeve.

FIG. 5 is a schematic sectional view of an anchor structure.

FIG. 6 is a cross-sectional view of an unbonded PC steel stranded wire.

FIG. 7 is a cross-sectional view of an unbonded PC steel stranded wire.

FIG. 8 is an explanatory diagram showing a conventional heat-shrinkable sleeve heating method.

[Explanation of symbols]

1 heating part 2 space 3 handle 4 tongue 5 spindle 6 grip 7 heat shrink sleeve 8 Shield 9 jacket 10 heartwood 13 Slope 14 anchor head 15 Anchor body 16 anchor holes 17 PC steel stranded wire 18 strands 19 Preventive ingredients 20 Anticorrosion layer 25 Free Length 26 Fixed section 27 grout

─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Taiji Mikami 1-3-12 Moto-Akasaka, Minato-ku, Tokyo Sumitomo Electric Industries, Ltd. Tokyo Head Office (56) References Japanese Patent Laid-Open No. 10-30213 (JP, A) ) Japanese Patent Laid-Open No. 9-70890 (JP, A) Actual Development Sho 55-83324 (JP, U) Actual Public Sho 59-35371 (JP, Y1) (58) Fields investigated (Int.Cl. ⁷ , DB name) E04C 5/12 E04G 21/12 104 B29C 63/42

Claims (5)

(57) [Claims] 1. A heating portion having a concave cross section which is configured to be openable and closable and covers the entire length and the entire circumference of a heat-shrinkable sleeve, and an outer surface to be covered, which is formed on an inner surface of the heating portion at both ends of the heating portion.
A heat-shrinkable sleeve shrinking device , comprising: a heat-insulating material disposed on at least the inner peripheral surface of the gripping part ; 2. The outside of the heat shrink sleeve at both ends of the heating section
The heat-shrinkable sleeve shrinking device according to claim 1, further comprising a shielding part that closes a space between the outer surface of the object to be coated and the inner surface of the heating part so as to be located at the position . 3. An inside diameter of the gripping portion is configured so that the inner diameter of the gripping portion can correspond to an object to be coated having a different outer diameter by detachably attaching an arcuate member having a different diameter to the inner circumference of the gripping portion. Item 2. A heat-shrink sleeve shrink device according to Item 1. 4. A process according to claim 1 , wherein the outer periphery of the object to be coated is covered with a heat shrink sleeve.
The grip of the shrinking device of the shrinking sleeve is applied to the outer surface of the object to be coated.
A step of covering the entire length and the entire circumference of the heat-shrink sleeve with the heating section of the shrinking device while maintaining the inner surface of the heat section, and a step of heating and shrinking the heat-shrink sleeve by the heating section. Shrink method of heat shrink sleeve. 5. The coating object is a boundary between a free length portion and a fixed length portion in an unbonded PC steel material.
The shrinking method of the heat shrinkable sleeve according to claim 4 .