JPH09210277A - Terminal protecting pipe for double pipe - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily perform mounting in an end part of a double pipe and facilitate, after mounting, connection work between an inner pipe of the double pipe and a pipe joint, relating to a terminal protecting pipe for the double pipe used in water service piping or the like in the indoor. SOLUTION: A terminal protecting pipe 11, extensible/contractible in the lengthwise direction, is provided with a bellows pipe part 12 capable of self- holding an extending/contracting condition. A sheath pipe mounting part 13 is formed in one end side of the bellow pipe part 12, and a pipe joint storage part 14 is formed in the other end side. A coming off-preventing part 15 engaged with corrugation of a sheath pipe 2 is formed in the sheath pipe mounting part 13. The bellows pipe part 12 is placed in a contracting condition, and connection work to a pipe joint 3 of an inner pipe 1 can be performed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a terminal protection pipe attached to the end of a double pipe used for indoor water pipes and the like.

[0002]

2. Description of the Related Art Double pipes used for indoor water pipes include a plastic inner pipe (usually a straight pipe) that allows a fluid such as tap water to pass through, and a plastic sheath pipe (usually a corrugated pipe). ) Is stored inside. This double piping is flexible and has an advantage that piping work can be easily performed.

At the terminal portion of such flexible double piping, terminal processing as shown in FIG. 5 is performed. In the figure, 1
Is an inner pipe of double pipe, 2 is the same sheath pipe, 3 is a pipe joint, 4
Is a header and 5 is a terminal protection tube. The terminal protection tube 5 is
This is a structure in which a pipe joint housing portion 7 is integrally provided on the upper end of a tubular portion 6 inserted between the inner pipe 1 and the sheath pipe 2.

In the terminal treatment, first, the end portion of the sheath tube 2 is cut off by the required length to expose the end portion of the inner tube 1 by the required length. Next, the tubular portion 6 of the terminal protection tube 5 is connected to the inner tube 1 and the sheath tube 2.
Insert between Then, the inner pipe 1 is projected from the upper end of the pipe joint housing 7. At this time, the protruding length of the inner pipe 1 is set to a length that facilitates the work of gripping the end portion of the inner pipe 1 by hand and connecting to the pipe joint 3. Then, the end portion of the inner pipe 1 is inserted into the pipe joint 3 and the pipe joint 3 is tightened to fix the inner pipe 1. Next, the terminal protection pipe 5 is pulled up, and the pipe fitting 3 is placed in the pipe fitting housing 7.
To store. The length of the tubular portion 6 of the terminal protection pipe 5 is set in advance so that the lower end of the tubular portion 6 is located in the sheath pipe 2 in a state where the pipe joint 3 is housed in the pipe joint housing portion 7. .

With such a terminal structure, the inner pipe 1 projecting above the upper end of the sheath pipe 2 is protected by the terminal protection pipe 5, and water is tentatively supplied from the connecting portion between the inner pipe 1 and the pipe joint 3. Even if there is a leak or the like, the leaked water can be prevented from immediately leaking to the outside because the leaked water is guided into the sheath 2.

As a terminal protection tube different from the above-mentioned terminal protection tube, a sheath tube mounting portion to be mounted on the outside of the sheath tube is provided on one end side of the bellows tube portion which is elastic in the longitudinal direction, and the other end side thereof. A pipe fitting housing is also proposed (Japanese Utility Model Laid-Open No. 4-50463). With this terminal protection tube, the sheath tube mounting part is attached to the end of the sheath tube, the bellows tube part is contracted, the inner tube is connected to the pipe joint, and then the bellows tube part is extended and the tube is extended. By accommodating the pipe joint in the joint accommodating portion, the same effect as described above is obtained.

[0007]

However, in the terminal protection pipe shown in FIG. 5, since the tubular portion has to be inserted considerably deeply between the inner pipe and the sheath pipe of the double pipe, the double pipe has a pipe shape. When bent near the joint, it is difficult to insert the tubular portion because the inner tube and the sheath tube are in strong contact with each other due to the repulsive force against bending. In addition, a silencer tape may be interposed between the inner pipe and the sheath pipe in order to prevent noise from being generated due to collision of the inner pipe with the sheath pipe by a water hammer or the like. Since there is almost no space between the pipe and the sheath pipe, the pipe portion of the terminal protection pipe cannot be deeply inserted between the inner pipe and the sheath pipe.

Further, since the terminal protection tube having the elastic bellows tube portion is in a steady state when the bellows tube portion is in a steady state, the bellows tube portion may be used when connecting the inner pipe to the pipe joint. There is a problem that it is difficult to carry out the work because it is necessary to hold it in a contracted state against the elasticity.

In view of the above problems, an object of the present invention is to attach a double pipe to an end of the double pipe and to easily connect the inner pipe to the pipe joint. To provide a protective tube.

[0010]

A terminal protection tube for double pipes according to the present invention has an inner diameter into which an inner pipe of double pipes can be inserted, is expandable and contractible in a longitudinal direction, and is in an expanded state and a contracted state. A bellows tube portion capable of self-holding is provided, a sheath tube fitting portion to be mounted on the sheath of the double pipe is formed at one end side of the bellows tube portion, and a pipe joint for the inner pipe is accommodated at the other end side. A pipe joint accommodating portion is formed, and a retaining portion that engages with the waveform of the sheath pipe is formed in the sheath pipe mounting portion.

The pipe joint housing portion of the terminal protection pipe of the present invention may be a bellows pipe having an inner diameter into which the pipe joint is inserted.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION

[Embodiment 1] FIGS. 1A and 1B show an embodiment of the present invention. In this terminal protection pipe 11, a sheath pipe mounting portion 13 is formed on one end side of a bellows pipe portion 12 having an inner diameter into which an inner pipe of a double pipe can be inserted, and a pipe joint housing portion 14 is formed on the other end side. That is, it is similar to the terminal protection tube disclosed in Japanese Utility Model Laid-Open No. 4-50463. In the drawings, the wall thickness of the bellows tube portion 12 is omitted.

The characteristic of this terminal protection tube 11 is that the bellows tube section 1
2 is expandable / contractible in the longitudinal direction, and is capable of self-holding the extended state as shown in (a) and the contracted state as shown in (b). That is, the protrusions 15 for preventing the slip-off which are engaged with the corrugated shape of the sheath tube are formed.

In order to enable the bellows tube portion 12 in this embodiment to hold the stretched state and the contracted state by itself, as shown in FIG. 1 (a), each corrugation has one waveform from the top of the mountain. The length G to the bottom of the valley is different from the length H to the bottom of the other valley. This way,
Since the diameter of the top of the mountain and the diameter of the bottom of the valley are constant, the longer slope g and the shorter slope h as shown in (a).
Is on both sides of the crest of the mountain (extended state), its shape can be stably maintained, and the short slope h has entered the inside of the long slope g (shrinkage) as in (b). The shape can be stably maintained even in the state. Therefore, the stretched state and the contracted state can be self-maintained. The angle θg formed by the surface passing through the top of the mountain and one slope g is larger than the angle θh formed by the surface passing through the top of the mountain and the other slope h.

FIG. 2 shows a usage state of the terminal protection tube 11 of FIG. In FIG. 2, 1 is an inner pipe of double pipe, 2 is a sheath pipe, 3 is a pipe joint, and 4 is a pipe branch header. First, as shown on the left side of FIG.
The inner pipe 1 is made to project from the end of the required length by the required length. Next, the terminal protection tube 11 is set in a state in which the bellows tube portion 12 is contracted, the inner tube 1 is inserted therein, and the sheath tube mounting portion 13 is attached to the end portion of the sheath tube 2. Then, the ridges 15 on the inner surface of the sheath tube mounting portion 13
However, since it cuts into the corrugated valley portion of the sheath tube 2, the sheath tube mounting portion 13 cannot be easily pulled out from the sheath tube 2.

Next, as shown in the center of FIG. 2, the end portion of the inner pipe 1 is inserted into the pipe joint 3 for tightening connection. This work can be easily performed without pressing the terminal protection tube 11 because the bellows tube portion 12 of the terminal protection tube 11 is in a contracted state. Next, as shown on the right side of FIG.
4 is pulled up, the bellows pipe portion 12 is extended, and the pipe joint 3 is stored in the pipe joint storage portion 14. At this time, since the sheath tube mounting portion 13 is locked to the sheath tube 2 by the ridge 15, it cannot be pulled out from the sheath tube 2. Further, the bellows tube portion 12 can self-hold the shape after being stretched. Therefore, this work can be performed very easily.

If it is necessary to inspect the connection between the inner pipe 1 and the pipe joint 3 thereafter, the bellows tube portion 12 may be contracted as shown in the center of FIG. The tube portion 12 may be stretched and returned to the state on the right side of FIG.
Therefore, inspection work can be performed easily.

The terminal protection pipe 11 can be used not only in the portion connecting the end of the double pipe to the header 4 but also in the portion connecting the end of the double pipe to the faucet.

[Embodiment 2] FIGS. 3A and 3B show another embodiment of the present invention. The terminal protection pipe 11 is different from the terminal protection pipe of FIG. 1 in that the pipe joint housing portion 14 is a bellows pipe having an inner diameter into which the pipe joint is inserted. Since other configurations and usages are the same as those of the terminal protection tube of FIG. 1, the same parts are designated by the same reference numerals and the description thereof will be omitted.

[Embodiment 3] FIGS. 4A and 4B show still another embodiment of the present invention. The terminal protection tube 11 is different from the terminal protection tube of FIG. 1 in the structure of the bellows tube portion 12. That is, the bellows tube portion 12 is formed by connecting a large number of annular members 16 having a substantially "self-shaped" cross section, and attaching packings 17 to the connecting portions so that adjacent annular members 16 are slidably frictionally coupled to each other. is there. Even in such a structure, the bellows tube portion 12 is in a stretched state as shown in (a), and (b)
It is possible to self-hold the contracted state such as. Since other configurations and usages are the same as those of the terminal protection tube of FIG. 1, the same parts are designated by the same reference numerals and the description thereof will be omitted.

[Other Embodiments] In the above embodiments, the case where the sheath tube mounting portion is mounted outside the sheath tube has been described, but the sheath tube mounting portion may be structured to be mounted inside the sheath tube. it can. In that case, on the outer surface of the sheath mounting part,
It suffices to form a retaining portion that engages with the corrugation of the sheath tube.
Even with such a structure, it is not necessary to deeply insert the sheath mounting portion into the sheath, so that the sheath can be easily attached to the end of the double pipe.

[0022]

As described above, since the terminal protection pipe according to the present invention has no portion to be inserted deeply between the inner pipe and the sheath pipe, even if the double pipe is bent near the pipe joint, the double pipe is bent. It can be easily attached to the end of the pipe. Also, when the inner pipe is connected to the pipe joint, the bellows pipe can hold itself in the extended state and the contracted state, and the sheath mounting part is formed with a retaining portion that engages with the corrugation of the sheath pipe. Or
When checking the connection between the inner pipe and the pipe joint, it is not necessary to press the bellows tube part in a contracted state, and it is not necessary to press the sheath mounting part when the bellows tube part is extended. Therefore, connection work and inspection work can be easily performed.

[Brief description of drawings]

FIG. 1 shows an embodiment of a terminal protection tube according to the present invention, (a) is a front view of a half incision with a bellows tube extended.
(B) The front view of the half incision with the bellows tube contracted.

FIG. 2 is a cross-sectional view showing an example of a usage state of the terminal protection tube of FIG.

FIG. 3 shows another embodiment of the terminal protection tube according to the present invention, (a) is a front view of a half incision with the bellows tube extended.
(B) The front view of the half incision with the bellows tube contracted.

4A and 4B show another embodiment of the terminal protection tube according to the present invention, where FIG. 4A is a front view of the bellows tube with the bellows tube extended, and FIG. 4B is a half of the bellows tube with the bellows section contracted. Front view of the incision.

FIG. 5 is a cross-sectional view showing a usage state of a conventional terminal protection tube.

[Explanation of symbols]

 1: Inner pipe 2: Sheath pipe 3: Pipe joint 4: Header 11: Terminal protection pipe 12: Bellows pipe portion 13: Sheath pipe mounting portion 14: Pipe joint storing portion 15: Protrusion strip for retaining

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Katsuhiko Shiragin 2-6-1 Marunouchi, Chiyoda-ku, Tokyo Furukawa Electric Co., Ltd.

Claims (1)

[Claims] 1. A bellows tube portion (12) having an inner diameter into which an inner pipe (1) of a double pipe can be inserted, expandable and contractible in a longitudinal direction, and capable of self-holding an expanded state and a contracted state, A sheath pipe mounting portion (13) to be mounted on the sheath pipe (2) of the double pipe is continuously provided on one end side of the bellows pipe portion, and an inner pipe (1) is mounted on the other end side thereof.
The pipe fitting housing (14) for housing the pipe fitting (3) for use in the same is continuously provided, and the sheath fitting portion (13) is provided with a retaining portion (15) that engages with the waveform of the sheath pipe (2). ) Is formed, the terminal protection tube of flexible double piping.