JPH0942560A - Metallic tube coupling for resin tube - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an excellent junction between a small diameter hot water supplying polybutene tube and a tube coupling. SOLUTION: In a tube coupling made up of a coupling main body 2 provided with a tube insertion part 6 having both a mounting part 3 at is one end side, and a volute groove 5 at the other end side, and with a screw part 8 threadedly fastening a presser nut 7 in between the aforesaid part and groove, and of a cap nut 17 threadedly engaged with the presser nut 7, a space in a V shape at its depth is formed between the tube insertion part 6 and the presser nut 27. A core 19 which is inwardly fitted in the cap nut 17, has the insertion part of a polybutene tube 22 fitted in, and has projections 21 in its circumference, is formed out of a diameter contracting ring C. When the cap nut is tightened, the core 19 and the polybutene tube 22 are integrally pushed in to the V shaped space 16 so as to be held between the volute groove 5 and each projection 21, sealing and retaining performance for the whole of the insertion part of the tube 22 can thereby be excellent.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a metal pipe joint for a resin tube, and more particularly to a metal pipe joint for joining a small diameter water supply or hot water supply resin tube to another member. It is a thing.

[0002]

2. Description of the Related Art Recently, resin tubes such as polybutene tubes, PVC tubes, and polyethylene tubes have been used in place of metal tubes used as water supply or hot water supply tubes.

That is, conventionally, when connecting a copper pipe to a faucet, the copper pipe is bent, bent, or rolled into a predetermined shape.
It was necessary to attach and connect them, but if it is a resin tube, these operations are unnecessary, and interference with other members on piping can be avoided, and piping work is extremely easy. (For example, see Japanese Utility Model Publication No. 7-26451 and Japanese Utility Model Publication No. 7-21664).

By the way, even a resin tube having such a characteristic cannot be used for a hot water supply pipe requiring heat resistance.
Recently, not only corrosion resistance, but also polybutene tube (a polyolefin-based resin with an ultra-high molecular weight, which has high strength even at high temperatures, has excellent flexibility, heat-creep characteristics, and stress crack resistance. ) Has been standardized so that it can be used for water and hot water supply pipes (see JISK6778).

Therefore, this polybutene tube is
It has become widely used for heating pipes for greenhouses and vinyl houses, and for floor heating pipes for houses and livestock sheds.

By the way, a metal pipe joint is required to connect the polybutene tube to another pipe type or a metal instrument. At that time, however, the polybutene tube is different from a copper pipe after construction and is free from friction. -It is very convenient because it may be left in a negative state, and it may be able to actively swing in response to an earthquake, but instead, water leakage or escape at the joint with the pipe joint, etc. Need to be considered.

On the other hand, various proposals have been made for metal pipe joints for joining general resin tubes (for example, Japanese Utility Model Laid-Open No. 58-172178, JP-A No. 2-16).
3592, etc.).

[0008] One of such proposals, Japanese Patent Laid-Open No. 2-
The pipe joint described in Japanese Patent No. 163592 will be described.

In FIG. 3, a joint main body 51 of the pipe joint 50 is provided with a mounting threaded portion 52 at one end and a tube insertion portion 54 having a packing groove 53 at the other end. Further, a support flange portion 55 for fitting a press nut is formed at a substantially intermediate portion thereof.

The holding nut 56 fitted to the support flange 55 is a hexagonal portion 57 for fitting and a reduced diameter portion (corresponding to a so-called ferrule) 58 having a male screw engraved.
It consists of:

A cap nut 59 is attached to the reduced diameter portion 58.
The cap nut 59 is screwed, and a diameter-reducing inclined surface 60 is formed on the inner surface of the cap nut 59 opposite to the screw side. A packing 61 is fitted in the packing groove 53.

In order to join the resin tube 62 made of polyethylene or the like to the pipe joint 50, the resin tube 62 is cut along a cutting line (not shown) orthogonal to the tube axis. , Clean the cut tube. Next, the cut resin tube 62 is manually inserted into a doughnut-shaped space 63 formed by the tube insertion portion 54 and the reduced diameter portion 58, and the insertion tip is supported by the support flange 55. Abut the side surface of.

Next, a spanner (not shown) is hung on each of the press nut 56 and the cap nut 59 to make the cap nut 59.
When tightened, the inclined surface 60 of the cap nut 59 presses the reduced diameter portion 58 having a plurality of slits (not shown) in the axial direction to reduce the diameter.

As a result, the tip end side of the reduced diameter portion 58 deforms the outer shape of the resin tube 62, so that the resin tube 62 is pressed against the packing 61. Therefore, the resin tube 6
2 is a tube fitting 50, a tube insertion portion 54 and a reduced diameter portion 5
It is clamped by 8 to prevent it from coming off, and packing 61
Sealed by crimping with.

A resin tube is attached to the base of the reduced diameter portion 58.
A plurality of insertion check holes 64 are provided for the resin tube.
Confirm that the bush 62 is inserted into the space 63.

[0016]

When a resin tube, for example, a polybutene tube, is joined to the metal pipe joint 50, there are the following problems.

1) The pipe joint 50 is provided with a donut-shaped space 63 having a slight allowance so that a polybutene tube can be inserted therein, and the space 63 is reduced in diameter by a reduced diameter portion 58. It does not contribute to the sealing or retaining of the polybutene tube except where

2) Since the polyb dent tube is manually inserted all the way into the space 63, if there is an error in the outer diameter of the polyb dent tube (extrusion molding of the polyb dent tube is carried out by controlling the inner diameter). Therefore, it is difficult to insert the outer diameter.

3) Since the outer shape of the polybutene tube is deformed and is crimped to the tube insertion portion 54 of the joint main body 51 only at the tip end side of the reduced diameter portion 58, it is difficult to prevent it from coming off. Remains. This anxiety is particularly great when the piping is not fixed after the construction and the pipe is swingable in response to an earthquake.

[0020]

SUMMARY OF THE INVENTION Therefore, the present invention has been made to solve the above problems, and its gist is to provide a mounting portion at one end and a tube insertion portion at the other end. , And a fitting main body formed with an attachment portion for attaching the press nut, respectively, and a cap nut screwed to the press nut, between the tube insertion portion and the press nut. In a metal pipe joint in which a donut-shaped space for inserting a resin tube is formed, in the space, the insertion side of the resin tube is fitted to its inner circumference, and a cap nut is fitted to its outer circumference. Inserting the loosely fitted diameter-reducing core integrally with the resin tube by pushing it in with the pushing piece of the cap nut and reducing the diameter of the core with the holding nut Special feature is that it has been sealed and retained over the entire length of the part. And a resin Joo - in blanking metal pipe joint.

[0021]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in detail with reference to the drawings showing the embodiments thereof. 1 is a sectional view of an embodiment of the present invention, (A) is a sectional view before joining, (B) is a sectional view after joining, and FIG. 2 is a header of an application example of the pipe joint of FIG. .

The pipe joint of this example has a nominal diameter of 10 mmφ to 30 mm.
It is suitable for a brass pipe joint for joining a polybuden tube of mmφ, particularly 13 mmφ or 15 mmφ, and for example, a polybudent tube having a nominal diameter of 13 mmφ has a wall thickness of 2 mm.

First, the pipe joint 1 will be described. On the joint body 2 of this pipe joint 1, a mounting portion 3 is formed on one end side, and a tube insertion portion 6 having an O-ring groove 4 and bamboo-shaped grooves 5 and 5 on the outer periphery is formed on the other end side, A stopper nut screw portion 8 for screwing the stopper nut 7 and a stopper 9 are formed adjacent to each other at a substantially middle portion thereof. An inclined surface 10 is formed near the O-ring groove 4 to increase the depth.
An O-ring 11 is fitted in the O-ring groove 4.

The holding nut 7 has a threaded portion on one end side inner periphery thereof that is screwed into a holding nut threaded portion 8 and a depth-reducing inclined surface 13 on the other end side inner periphery, and has an outer periphery for a cap nut. It comprises a holding portion 15 having a male screw portion 14.

Therefore, the upward slope 10 and the downward slope 13 have a V-shaped cross section with a V-shape.
6 is formed.

A cap nut 17 is screwed into the male screw portion 14 for the cap nut, and a pushing piece 18 is provided at the end of the cap nut 17 opposite to the screw side so as to protrude in the inner diameter direction. The pressing piece 18 presses the diameter-reducing core 19 into the V-shaped donut-shaped space 16 in cross section to firmly prevent the core from coming off.

The core 19 is made of brass and has a C-ring-shaped notch so that its diameter can be reduced and expanded. A V-shaped tip portion 20 is formed on the insertion tip side of the core 19 so as to correspond to the V-shaped donut-shaped space 16 in cross section, and the bamboo-shaped groove 5, 5 is formed on the inner surface of the rear end side of the core 19. Corresponding to No. 5, hemispherical projections 21 and 21 are formed.

A thin resin ring packing (not shown) is interposed between the pushing piece 18 of the cap nut 17 and the rear end of the core 19 so that the core 19 does not rotate together when the cap nut 17 is tightened. I have to.

The pipe joint 1 as described above is provided with a polybutene tube.
To join the bush 22, the cap nut 17 is loosened and the core 19 is positioned on the inlet side of the space 16 as shown in FIG. Then, the cut polytubular tube 22 which has been cut and cleaned is lightly inserted manually along the inner circumference of the core 19. That is, the insertion side of the polydube tube 22 is fitted into the core 19. Insertion length at that time is core 19
Since the axial length is equal to the width of the pushing piece 18, the insertion length can be accurately predicted in advance. That is, the tip of the polydube tube 22 on the insertion side is aligned with the tip of the core 19 on the insertion side.

Then, when a spanner (not shown) is applied to each of the press nut 7 and the cap nut 17, and the cap nut 17 is tightened, the pushing piece 18 pushes the core 19 toward the V-shaped donut-shaped space 16 in cross section. As the core 19 is gradually inserted, the diameter of the core 19 is gradually reduced by the inclined surface 13 of the press nut 7. Pushed in. This pushed state is shown in FIG.

As is apparent from FIG. 1 (B), the insertion tip side of the polydube tube 22 is sandwiched between the O-ring 11 and the V-shaped tip portion 20, and the opening is folded into a trumpet shape. It is bent, sealed, and prevented from falling out. Since this is the polybutene tube 22, cracks do not occur even when bent by being pushed.

On the rear end side of the inserted polydube tube 22, the outline is deformed by the bamboo-shaped grooves 5 and 5 and the hemispherical projections 21 and 21 to become wavy, and the bamboo-shaped groove 5 and the hemispherical projection 21 are formed. It is sandwiched and prevented from coming off. In particular, not only the concave groove but also the bamboo-shaped groove 5 doubles the retaining force.

Therefore, since the entire insertion portion of the polybutene tube 22 is sealed and prevented from coming off,
These can be ensured.

Next, an example in which the pipe joint 1 is applied to the floor heating header 23 will be described.

In FIG. 2, a header pipe 24 is a pipe body in which a brass rod is pierced, and a joint 25 for connecting to a water heater (not shown) is screwed to one end of the pipe 24 and the other end thereof. The closing bolt 26 is screwed on. Of course, other header tubes may be connected. A large number of paired pipe joints 1, 1 ... Are attached to the header pipe 24. The structure of this pipe joint 1 is as described above. The mounting portion 3 of the pipe joint 1 and the header pipe body 24 are
The connection is made by attaching a wire. Of course, this mounting part 3
It may be configured by a mounting screw body portion as shown in FIG. 3 and screwed to the header tube body 24.

Therefore, the large number of pipe joints 1 as described above
In the work of joining the polybutene tubes 22, the polybutene tubes 22 can be simply tightened by tightening the cap nuts 17.
It is possible to surely insert the bush 22 by pushing it, and seal or prevent it from coming off. In particular, after the construction, even if the polyb dent tube 22 is set in a free state in the middle so that it can be swung in response to an earthquake, the seal and the retainer are surely secured, and the floor heating etc. It is convenient for places that are difficult to see.

In the pipe joint 1, in order to integrate the joint main body 2 and the press nut 7, the press nut 7 is screwed into the screw portion 8 provided in the joint main body 2 and screwed by the stopper-9. Although the structure is such that the joint body 2 and the press nut 7 are integrated, the present invention is not limited to this, and a detent fit by hexagonal portions as shown in FIG. 3 may be used. The integration of these is called attachment in this specification.

[0038]

According to the present invention, the diameter-reducing core and the resin tube are integrated and pushed in by a cap nut, so that the resin tube is sealed and prevented from coming off over the entire length of the insertion portion of the resin tube. Therefore, the resin tube insertion work can be done easily and without any insufficient insertion, and the sealing and retaining can be done securely, and after the installation, pipe the resin tube in a swingable state. However, there are no water leaks or stoppers.

Further, by tightening the cap nut, the resin tube is inserted and the diameter for sealing and retaining is reduced, so that, for example, in a large number of pipe joints and narrow spaces such as floor heating pipes. The small-diameter piping work will be easier and the reliability after piping will be improved.

[Brief description of drawings]

FIG. 1 is a sectional view of an embodiment of the present invention, (A) is a sectional view before joining, and (B) is a sectional view after joining.

FIG. 2 is an application example of FIG.

FIG. 3 is a conventional example.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Pipe joint, 2 ... Joint body, 3 ... Attachment part, 4 ... Tube insertion part, 7 ... Press nut, 16 ... Space, 17 ... Cap nut, 18 ... Pushing piece, 19 ... Core, 22 ... Polybutene tube -

Claims (1)

[Claims] 1. A joint main body having a mounting portion on one end side, a tube insertion portion on the other end side, and an attachment portion for attaching a presser nut between the joint body and the presser nut. A cap nut to be screwed, and a metal pipe joint formed with a donut-shaped space for inserting a resin tube between the tube insertion portion and the press nut, wherein the space is made of resin. The diameter reducing core in which the insertion side of the tube is fitted to the inner circumference of the tube and the cap nut is loosely fitted to the outer circumference of the tube is integrated with the resin tube and pushed by the pushing piece of the cap nut. A metal pipe joint for a resin tube, characterized in that the core is reduced in diameter by the pressing nut while being inserted, thereby sealing and retaining the resin tube over the entire length of the insertion portion of the resin tube.