JPS5846301Y2 - Plastic spiral corrugated pipe connection sleeve - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION This invention relates to an improvement of a connecting sleeve for connecting plastic corrugated tubes having helical corrugations.

In recent years, plastic spiral corrugated tubes have been used for electrical conduits or fluid transport tubes for protecting various cables.

These plastic spiral corrugated tubes have excellent corrosion resistance and flexibility, making them easy to bend and pipe.They can also be supplied as long rolls and can be cut to the desired length when used. It has many advantages and is used in many applications.

By the way, these spirally corrugated pipes need to be connected airtightly in order to protect objects such as cables inserted into the pipe or leakage of fluid, and these connections are generally done as work. The following methods are used from the viewpoint of ease of use.

That is, as shown in FIG. 1, the spiral corrugated sleeve 2 for connection is placed in advance on one corrugated tube 1a, and in this state the connecting end of the other corrugated tube 1b is inserted into the corrugated tube. 1a, and immediately screw the connecting corrugated sleeve 2 placed on the corrugated tube 1a back onto the corrugated tube 1b.
As shown in the figure, the corrugated sleeve 2 covers the connection part, and then in order to improve the moisture resistance of the connection part, putty is stuffed into the gaps between the corrugated pipes 1a and 1b and the connection corrugated sleeve 2, In addition, a connecting portion was formed by wrapping the outside with tape or the like.

However, such a connection method not only requires a lot of manual labor and is inefficient, but also the watertightness depends largely on the skill level of the worker, and from the worker's perspective, it is difficult to stuff putty into the back of the connection. There are problems in that the connection tends to become unreliable and it is difficult to maintain sufficient water tightness at the joint.

Therefore, in an attempt to reduce such problems, a method has been used in which a heat-shrinkable sleeve is placed over the corrugated sleeve on the connection portion, and the sleeve is heat-shrinked to cover the corrugated sleeve airtightly.

However, with this method, it is necessary to attach a heat-shrinkable sleeve with a large inner diameter to the corrugated tube in advance, but in this case, as shown in Fig. 2, the heat-shrinkable sleeve 2 attached to the corrugated tube 1 is inevitably It will be located eccentrically.

If you heat-shrink the heat-shrinkable sleeve from the outside using a burner or the like in this state, unless you are a highly skilled person,
It is difficult to uniformly shrink the sleeve 2 over the outer circumference of the corrugated tube 1.

Therefore, in many cases, for example, as shown in FIG. The central part is first heated and shrunk to determine its position, and then the spacer 3 is removed and both ends of the sleeve 20 are heated with a burner.

However, this method requires the preparation of the spacers and the like for each work site, and the installation and removal of these spacers is cumbersome and extremely inefficient.

Furthermore, since the corrugated tube is a long product that is wound and supplied as described above, a bending line corresponding to the winding diameter remains in the longitudinal direction of the corrugated tube.

Due to this bending, when the corrugated tubes are butted against each other at the above-mentioned connection part, when the axis of one corrugated tube is aligned with the axis of the other corrugated tube, there is a repulsive force that causes the tube end of the other corrugated tube to shift. occurs.

Therefore, even if a corrugated connecting sleeve is fitted to this connecting part and the connecting pipes are aligned, the connecting corrugated sleeve immediately below the sleeve is simultaneously heated for heat shrinking when the heat-shrinkable sleeve attached to the outside of the connecting pipe is aligned. The attached sleeve is also heated and softened.

For this reason, the repulsive force remaining at the tube end becomes stronger than the restraining force of the connecting corrugated sleeve, and as a result, the connecting corrugated sleeve that has softened due to the displacement of the tube end may be deformed, or in extreme cases, There have also been cases in which the sleeve, which has been softened by heating, is broken due to the displacement of the tube ends, resulting in a complete failure in the connection operation and the failure of the housing.

As a result of intensive studies to solve this problem, the inventors have developed a connecting sleeve having the structure of the present invention. It has been discovered that various problems can be avoided at once, the work is made easier, and a plastic spiral corrugated pipe connection part that maintains a high degree of watertightness can be formed in a short time.

That is, as shown in FIG. 4, this invention has a concentric heat-shrinkable bonding agent layer 11 on the inner surface of a main body portion 10a that has a non-heat-shrinkable spiral waveform and is continuous with both ends of the main body portion 10a. This is a plastic spiral corrugated pipe connection sleeve having a structure including an enlarged diameter portion 10b.

An example of connecting spirally corrugated pipes using the spirally corrugated pipe connecting sleeve 10 of this invention will be described with reference to FIG.

That is, the connecting sleeve 10 of the present invention is screwed onto one side of the plastic spirally corrugated tube 12 in advance by applying the spirally corrugated portion of its main body to the position A, and after this state is achieved. , the other plastic spiral corrugated tube 13
Immediately, butt the pipe end 15 of the corrugated pipe 12 against the pipe end 14,
The connecting sleeve 10 is screwed back to the position B covering this abutting portion, and then the expanded diameter portion 1 of the connecting sleeve is screwed back.
0b is heated with a burner or the like to cause it to shrink.

In the same figure, reference numeral 16 denotes an adhesive applied by applying it in advance to the inside of the enlarged diameter portion 10b.

The length of the main body of the connecting sleeve of the present invention is preferably about 5 to 7 pitches of the corrugation pitch of the spirally corrugated tube to be connected.

Further, it is desirable that the length of the enlarged diameter portions 10a, 10b be approximately two to three times the corrugation pitch of the spirally corrugated tube to be connected.

Figures 6 to 8 show examples of the sleeve of the present invention, and the one in Figure 6 is a spirally corrugated tube 20 made of cross-linked plastic.
It is manufactured by stretching both end portions 20a and 20b concentrically as shown in the figure to expand the diameter thereof, thereby imparting heat-shrinkable strain to the turned portion, and providing an adhesive layer 21 on the inner surface thereof.

In addition, FIG.
722, the spirally corrugated sleeve 23 constituting the main body that can be externally inserted into the corrugated pipe to be connected is left with an unshrinked enlarged diameter portion 22' of a desired length at both ends via the adhesive 24. It is manufactured by heat-shrinking only the central part.

This type is more advantageous in manufacturing than the type shown in FIG. 6 because it does not involve partial stretching and diameter expansion.

Furthermore, FIG. 8 shows the heat-shrinkable tube 22 in the example of FIG.
Rather than using a full-length helical corrugated sleeve as shown in FIG. It is manufactured by heat-shrinking a certain length and integrating it, which makes the manufacturing work a little complicated, but it has the advantage of reducing material costs accordingly.

The plastic spirally corrugated pipe connecting sleeve of the present invention having the above-described structure is manufactured using commonly used cross-linked polyethylene, vinyl chloride, or fluorinated resin as appropriate, or manufactured by combining various parts of these materials. You may do so.

According to the connecting sleeve of this invention, as is clear from the above explanation and the examples described later, since the central main body is a non-heat-shrinkable corrugated tube, it can be easily attached to the corrugated tube connection portion during connection work. The positioning when unscrewing the screw is accurate and simple, and the airtightening work does not heat the main body, but only the concentrically enlarged diameter parts provided at both ends, as described above. There are no failures due to deformation of the connection sleeve, the work is significantly streamlined, and the watertightness of the connection is ensured by the heat-shrinkable material, eliminating the problems of the conventional technology. The industrial value is very large.

An application example of the present invention is shown below.

Application example: Thickness 2 as shown in Figure 7. Composite of Om/Wl rigid polyethylene helical corrugated sleeve and 0.8" 7m thick heat shrinkable tubing with 40% shrinkage, total length 290".
7m (portion with internal heat shrinkability, i.e. both ends of pot 60m/
WL) 0.6 ? ? Z/? Using a connecting sleeve with an adhesive layer of 7Z, an inner diameter of 10
A connecting portion of a 0 m/m hard polyethylene spirally corrugated tube (trade name: Eflex [F] manufactured by Furukawa Electric) was coated as described above to form a connecting portion.

This connection work could be completed in about 3 minutes by a normal worker.

When connecting the same spirally corrugated pipes using the conventional method described above, it took about 20 minutes for the same worker, but the working time was significantly shortened.

In addition, when we immersed the connection part using the above-mentioned connection sleeve of the present invention in 5% saline solution and examined the saline water intrusion into the pipe from the connection part, no water intrusion into the pipe was observed even after 5 years had elapsed. Ta.

[Brief explanation of the drawing]

1A and 1B are explanatory diagrams of an example of a conventional plastic spiral corrugated tube connection method; FIGS. 2 and 3 are explanatory diagrams of other connection examples of heat-shrinkable tubes; The figure is a partially cutaway front view of the connecting sleeve of the present invention, Figure 5 is an explanatory diagram of connection work using the connecting sleeve of the present invention, and Figures 6 to 8 are several implementations of the connecting sleeve of the present invention. FIG. 3 is a partially sectional front view of an example. 1.12,13...Spiral corrugated tube, 2,22.
...Heat-shrinkable sleeve, 3...Spacer, 10゜20-...Main body, 10a, 10b
, 20a, 20b... Expanded diameter portion, 11, 24,
21... Adhesive layer, 23... Connection sleeve.

Claims (1)

[Scope of utility model registration request] The main body part has a non-heat-shrinkable spiral waveform, and has concentric heat-shrinkable parts continuous to both ends of the main body part, and has an adhesive layer on the inner surface. Plastic spiral corrugated pipe connection sleeve.