JP2001021087A - Pipe joint - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a pipe joint which can provide a water-tight connection part even though the outer surface of a polyethylene resin pipe to be connected is sharply scored. SOLUTION: The inner peripheral surface of an annular recess 211 formed in the inner peripheral surface of a receptacle 21 of a joint body 2 has a tapered inner surface 212 having a diameter which is decreased toward the opening end thereof. A short cylindrical part 41 of a collet 4 having a flange 42 at one end of the short cylindrical part 41 is arranged in this annular recess 211, being loosely fitted therein, and a short cylindrical part 3 having a reduced diameter is integrally extended from the inner peripheral surface of the inward part of the joint body 2 to the opening end thereof, coaxial with the joint body 2, and a sealing ring 32 is fitted in an annular groove 31 formed in the outer peripheral surface of the short cylindrical part 3.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pipe joint which can be easily connected to a resin pipe for supplying a fluid and can provide a connection portion having excellent watertightness.

[0002]

2. Description of the Related Art Conventionally, a pipe joint which can be easily connected simply by inserting an end of a resin pipe into a joint body is disclosed in, for example, Japanese Patent Publication No. 51-14166, Japanese Patent Laid-Open No. 6-19378.
No. 7, US Pat. No. 4,0058,883 and the like disclose a pipe joint having substantially the same structure as that shown in FIG.

[0003] The pipe joint 1 shown in FIG. 5 comprises a joint body 2 made of brass and a collet 4 as a pipe tightening member which is arranged inside one end of the joint body 2 in a loosely fitted state. The joint body 2 is of a male screw type, one end of which is a receptacle 21 and the other end of which is a male screw connection 22.
For example, a polyethylene resin tube is connected to the receiving port 21, and a metal tube is connected to the male screw connection portion 22. An annular concave portion 211 is provided on the inner peripheral surface on the receiving port 21 side, and an inner peripheral surface of the concave portion 211 on the opening end side of the receiving port 21 is a tapered inclined inner peripheral surface 212.

[0004] A sealing rubber ring 3 is arranged on the inner side of the annular concave portion 211. An annular stopper 2 is provided on the inner peripheral surface of the boundary between the socket 21 of the joint body 2 and the male screw connection portion 22.
14 are integrally provided. Reference numeral 6 denotes a guide inner cylinder with a flange, which is arranged concentrically in the receiving port 21. The outer diameter of the inner cylinder 6 is substantially equal to the inner diameter of the connected polyethylene resin pipe.

As shown in FIGS. 6 and 7, the collet 4 has a flange 42 at one end of a short cylindrical portion 41. Wall portion 41 on the opposite side of flange 42 of short cylindrical portion 41
In FIG. 1, six inverted T-shaped notches 412 are formed along the axial direction so that the six arms 4 have an arc-shaped cross section.
13 are formed. The tip of each arm 413 is thick and is a tooth 414 having an inward blade 415.

The inner diameter of the short cylindrical portion 41 is slightly larger than the outer diameter of the polyethylene resin pipe to be connected, and the outer diameter of the flange 42 is substantially the same as the outer diameter of the socket 21 of the joint body 2. The outer diameter of the opposed tooth portions 414 in the free state is smaller than the maximum inner diameter of the annular recess 211 of the joint body 2 and larger than the inner diameter of the joint body 2 on the open end side. ing.

When the polyethylene resin pipe 5 is connected to the socket 21 of the joint body 2, the arm 4 of the collet 4
13 each tooth portion 414 is the inclined inner peripheral surface 21 of the joint body 2
2, the inward blades 415 bite into the outer surface of the polyethylene resin tube 5 as the entire six arm portions 413 are reduced in diameter in the radial direction. As a result, as shown in FIG.
The polyethylene resin pipe 5 is connected to the pipe joint 1.

In the above-mentioned pipe joint 1, when a pulling force acts on the polyethylene resin pipe 5 after the pipe connection,
The collet 4 moves together with the polyethylene resin pipe 5, and the outer surface of each tooth portion 414 comes into contact with the inclined inner peripheral surface 212 of the joint body 2, and each inward blade 415 cuts into the outer surface of the polyethylene resin pipe 5, Further removal of the polyethylene resin tube 5 is prevented.

[0009]

In the case of the above-mentioned conventional pipe joint, the annular recess 211 of the socket 21 of the joint body 2 is used.
Is pressed by the outer peripheral surface of the polyethylene resin tube 5, whereby the watertightness of the connection portion with the polyethylene resin tube 5 is ensured. However, when performing piping, the polyethylene resin pipe 5 may be dragged by an operator, and as a result, for example, a sharp scratch may occur on the outer surface of the polyethylene resin pipe 5. When such a polyethylene resin tube is used for pipe connection as it is, the watertightness of the connection portion is impaired, and there is a possibility that water leakage may occur.

[0010] An object of the present invention is to obtain a water-tight connection part even if the polyethylene resin pipe 5 connected at the construction site is dragged and a sharp scratch is made on the outer surface of the resin pipe. It is to provide a fitting that can be.

[0011]

According to a first aspect of the present invention, there is provided a pipe joint according to the present invention, wherein an inner peripheral surface of an annular concave portion provided on an inner peripheral surface of a receiving port of the joint main body is reduced in diameter toward an opening end side. A short cylindrical portion of a pipe tightening member having an inner peripheral surface and having a flange at one end of the short cylindrical portion is disposed in the annular concave portion on the inclined inner peripheral surface side in a loosely fitted state, and inside the pipe tightening member. A small-diameter short tube portion into which a resin tube to be connected is extrapolated is arranged concentrically with the axis of the joint body, and a seal ring is attached to an annular groove provided on the outer peripheral surface of the short tube portion. Is what it is.

According to a second aspect of the present invention, in the pipe joint according to the first aspect, a rear end portion of the short cylindrical portion is connected to an inner peripheral surface of the joint body.

According to a third aspect of the present invention, in the pipe joint according to the first aspect, the short tube portion is separate from the joint main body, and the outer peripheral surface of the short tube portion on the back side is the second tube portion. It is in contact with the inner peripheral surface of the joint body in a watertight manner via a seal ring.

According to a fourth aspect of the present invention, there is provided the pipe joint according to the first aspect, wherein an opening is provided in a wall of a receiving port of the joint body located on the back side of the seal ring.

(Function) In the pipe joint according to the first aspect of the present invention, a short cylindrical portion having a small diameter is concentric with the axis of the joint body inside the pipe fastening member disposed in the annular concave portion of the receiving port. Since the seal ring is attached to the annular groove provided on the outer peripheral surface of the short cylindrical portion, the resin pipe externally connected to the short cylindrical portion is connected to the seal ring at the inner peripheral surface thereof. The connection is made in a watertight manner. For this reason, even if there is a flaw or the like on the outer surface of the resin tube to be connected, there is no effect on the water tightness of the connection portion, and no water leakage or the like occurs.

As a result, a viewing window can be opened in the wall of the receptacle of the joint body, and the connection operation can be performed through the viewing window while checking the inserted state of the resin tube.

Further, since the short cylindrical portion of the pipe tightening member comes into contact with the inclined inner peripheral surface of the socket of the joint body and is reduced in diameter, it is possible to prevent the resin pipe inserted and connected from coming off.

In the pipe joint according to the second aspect of the present invention, since the short tubular portion is integrated with the joint main body, the connection can be achieved simply by inserting a resin pipe, and the connection portion has excellent watertightness. Can be obtained.

In the pipe joint according to the third aspect of the present invention, the short tube portion is separate from the joint main body, and the outer peripheral surface of the short tube portion on the inner side is interposed via the second seal ring. Since it is in contact with the inner peripheral surface of the joint body in a water-tight manner, it is possible to apply the resin pipe joint which is difficult to integrally mold by separately injection-molding the joint body and the short tube portion. .

In the pipe joint according to the fourth aspect of the present invention, an opening is provided in the wall of the socket of the joint body located on the back side of the seal ring. The connection work can be performed while confirming the insertion state of the resin pipe which is extrapolated and connected.

[0021]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a longitudinal sectional view showing a main part of a first embodiment of the pipe joint of the present invention, and FIG. 2 is a vertical sectional view of a main part showing a use state of the pipe joint of FIG.

The pipe joint 1 includes a joint body 2, a collet 4 as a pipe tightening member, and a short cylindrical section 3 as a guide.

The joint body 2 is, like the above-mentioned conventional one,
It is a brass male screw type, one end of which is a receptacle 2.
1. The other end is a male screw connection (not shown).
For example, a polyethylene resin tube is connected in the receiving port 21, and a metal tube is connected to the male screw connection portion. An annular concave portion 211 is provided on the inner peripheral surface of the receiving port 21 side, and the inner peripheral surface of the concave portion 211 on the opening end side of the receiving port 21 is
Tapered inclined inner peripheral surface 21 whose diameter decreases toward the open end side
It is 2. A circular hole 213 having a function as a viewing window is formed at one location on the wall of the receptacle 21.

The inner end of the short cylindrical portion 3 is connected to the inner peripheral surface of the joint body 2 and integrated therewith, and is arranged concentrically with the axis of the joint body 2. The outer diameter of the short cylindrical portion 3 is slightly smaller than the inner diameter of the polyethylene resin pipe to be connected, and the tip of the short cylindrical portion 3 projects outward from the open end of the receptacle 21. A substantially semicircular annular groove 31 is provided on the outer peripheral surface of the short cylindrical portion 3, and a seal ring 32 is mounted in the annular groove 31. The outer diameter of the short cylindrical portion 3 where the seal ring 32 is mounted is slightly larger than the inner diameter of the polyethylene resin pipe to be connected.

The collet 4 is made of a polyacetal resin having the same structure as the conventional one shown in FIGS. 6 and 7, and has a flange 42 at one end of the short cylindrical portion 41. Six inverted T-shaped notches 412 are formed in the wall portion 411 of the short cylindrical portion 41 on the side opposite to the flange 42 along the axial direction, so that the six cross-sectional arms are arc-shaped. A part 413 is formed. The tip of each arm 413 is thick and has a tooth 414 having an inward blade 415.
It has been.

The inner diameter of the short cylindrical portion 41 is slightly larger than the outer diameter of the polyethylene resin pipe to be connected, and the outer diameter of the flange 42 is substantially the same as the outer diameter of the socket 21 of the joint body 2. The outer diameter of the opposed tooth portions 414 in the free state is smaller than the maximum inner diameter of the annular recess 211 of the joint body 2 and larger than the inner diameter of the joint body 2 on the open end side. ing.

The short cylindrical portion 41 of the collet 4 is loosely fitted in a gap between the socket 21 of the joint body 2 and the outer surface of the short cylindrical portion 3 for guiding. And the joint body 2
When the polyethylene resin pipe 5 is connected to the receiving port 21, each tooth 414 at the tip of the arm 413 of the collet 4 is pressed by the inclined inner peripheral surface 212 of the joint body 2, and the six arms 4
13 is reduced in diameter in the radial direction, so that each inward blade 41
5 bites into the outer surface of the polyethylene resin pipe 5, and as a result, the polyethylene resin pipe 5 is connected to the pipe joint 1 as shown in FIG.

Next, the usage of the pipe joint 1 will be described. First, as shown in FIG. 2, the end of the polyethylene resin pipe 5 is inserted into a gap between the inner surface of the collet 2 and the outer surface of the guide short cylindrical portion 3 which is concentrically and integrally arranged in the socket 21 of the joint body 2. Insert the part. At this time, the state of insertion of the polyethylene resin tube 5 to be inserted can be confirmed through the viewing window 213 provided on the wall of the receptacle 21, so that a connection operation can be performed without an operation error such as insufficient insertion.

Further, the polyethylene resin pipe 5 to be connected has its inner peripheral surface sealed in a watertight manner by a seal ring 32 attached to an annular groove 31 on the outer peripheral surface of the short cylindrical portion 3.
Even if the outer surface of the polyethylene resin tube 5 is scratched, the watertightness of the connection portion is not affected at all.
In the state shown in FIG. 2, even if an external force acts on the polyethylene resin pipe 5 in the direction of the arrow, the polyethylene resin pipe 5 is detached from the inside of the joint main body 2 by the biting of the inward blade 415 of the collet 2. Can be prevented.

FIG. 3 is a longitudinal sectional view showing a main part of a pipe joint according to a second embodiment of the present invention, and FIG. 4 is a vertical sectional view showing a main part of the pipe joint shown in FIG.

In the case of the second embodiment, the short cylindrical portion 3 for guiding is formed separately from the joint body 2, and the second groove is formed in the annular groove 34 provided on the outer peripheral surface of the flange 33 of the short cylindrical portion 3. Of the first embodiment, except that the flange 33 of the short cylindrical portion 3 is brought into contact with the inner peripheral surface of the joint body 2 in a watertight manner via the seal ring 35. Is basically the same as

In the second embodiment, since the short cylindrical portion 3 is separate from the joint body 2, even if the joint body 2 is made of a resin such as polyphenylene sulfide (PPS) resin, for example, it is injection molded. It is possible by separately injection-molding the joint body 2 and the short cylindrical portion 3 respectively.

In the above embodiment, the collet is made of resin, but may be made of metal.

[0034]

According to the pipe joint of the present invention, the seal ring is provided in the annular groove on the outer peripheral surface of the short cylinder portion which is arranged concentrically with the axis of the joint body inside the pipe tightening member. Is attached, so that the resin pipe that is extrapolated and connected to this short cylinder is sealed in a watertight manner by a seal ring on its inner peripheral surface, and there are scratches on the outer surface of the resin pipe. Even if
There is no effect on the watertightness of the connection and no water leakage occurs.

For this reason, a viewing window can be provided in the wall of the receptacle of the joint main body, and through this viewing window, the insertion state of the connected resin tube can be checked, and work errors such as insufficient insertion can be prevented. it can.

Further, since the diameter of the short cylindrical portion of the pipe fastening member is reduced at the inclined inner peripheral surface of the receiving port, it is possible to prevent the resin pipe to be inserted and connected from coming off.

In the pipe joint according to the second aspect of the present invention, connection can be achieved by simply inserting a resin pipe, and a connection portion having excellent watertightness can be obtained.

In the pipe joint according to the third aspect of the present invention, in particular, in the case of a resin pipe joint which is difficult to integrally mold, it can be applied by separately molding the joint body and the short tube portion. Become.

In the pipe joint according to the fourth aspect of the present invention, the short pipe portion is formed by using an opening provided in the wall of the receptacle of the joint body located on the back side of the seal ring as a viewing window. The connection operation can be performed while checking the insertion state of the resin pipe to be connected by extrapolation to the connector, and an operation error such as insufficient insertion can be prevented.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing a main part of a first embodiment of a pipe joint according to the present invention.

FIG. 2 is a longitudinal sectional view showing a use mode of the pipe joint of FIG.

FIG. 3 is a longitudinal sectional view showing a main part of a second embodiment of the pipe joint of the present invention.

FIG. 4 is a longitudinal sectional view showing a use mode of the pipe joint of FIG. 3;

FIG. 5 is a longitudinal sectional view showing a conventional pipe joint together with a use state.

FIG. 6 is a front view showing the collet in FIG. 5;

FIG. 7 is a sectional view taken along line XX of FIG. 6;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Pipe joint 2 Joint main body 21 Receptacle 211 Annular concave part 212 Slant inner peripheral surface 213 Circular hole (sight window) 22 Male screw connection part 3 Short cylindrical part 31, 34 Annular groove 32, 35 Seal ring 33 Flange 4 Collet (Tightening pipe) 41) Short cylindrical section 412 Notch section 413 Arm section 414 Tooth section 415 Inward blade 42 Flange 5 Polyethylene resin pipe

Claims (4)

[Claims] An inner peripheral surface of an annular concave portion provided on an inner peripheral surface of a receiving port of a joint body has an inclined inner peripheral surface whose diameter decreases toward an opening end side, and the annular concave portion on the inclined inner peripheral surface side. A short cylindrical portion of a pipe fastening member having a flange at one end of the short cylindrical portion is arranged in a loosely fitted state, and a small diameter short cylindrical portion into which a resin pipe to be connected is extrapolated inside the pipe fastening member. Is arranged concentrically with the axis of the joint main body, and a seal ring is mounted in an annular groove provided on the outer peripheral surface of the short cylindrical portion. 2. The pipe joint according to claim 1, wherein a rear end of the short cylindrical portion is connected to an inner peripheral surface of the joint body. 3. The short cylinder portion is separate from the joint body,
The pipe joint according to claim 1, wherein an outer peripheral surface on a deep side of the short cylindrical portion is in water-tight contact with an inner peripheral surface of the joint main body via a second seal ring. 4. An opening is provided in a wall of a receiving port of a joint body located on a back side of a seal ring.
The described pipe fitting.