JP2006242348A - Pipe joint - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a pipe joint of an inside seal type having high sealing performance by giving uniform fastening force to a connected pipe from the outer periphery side. <P>SOLUTION: The pipe joint comprises an inner cylinder portion and an outer cylinder portion provided outside the inner cylinder portion with a predetermined gap into which the connected pipe is inserted. The inner cylinder portion has a seal member on the outer periphery and a spring ring inside the outer cylinder portion in opposition to the seal member. The spring ring is formed into a double ring of approximately U-shaped cross section with an outer periphery piece and an inner periphery piece connected to each other at the side of inserting the connected pipe. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a pipe joint, and more particularly, to an inner seal type pipe joint that can be connected simply by inserting a connected pipe.

In the type of sealing on the inner peripheral side of the connected pipe, a technique of fastening with an elastic ring from the outer peripheral side of the connected pipe is known for the purpose of improving water stoppage.
For example, JP-A-2002-031282 discloses a ring as shown in FIG.
This type of elastic ring body employs a system in which a slit portion is formed in the ring body and a certain diameter-enlarged piece is sandwiched in order to secure a gap for insertion of the connected pipe.
Specifically, referring to FIG. 8, the tightening ring 120 having a C-shaped cross section extends from the state in which the slit 121 portion shown in FIG. 8 is tightened on the outer periphery of the connected pipe 101 as shown in FIG. 8 (b). However, the tightening force is not uniform in the circumferential direction of the tightening ring 120 due to the slit portion. As compared with the above, there is a problem that the tightening force at the slit 121 portion and the C and D portions which are opposite to the slit 121 portion is weak and water leakage from the C and D portions is likely to occur.

JP 2002-031282 A

  In view of the above technical problem, an object of the present invention is to provide a pipe joint that has a uniform sealing force from the outer peripheral side in the inner seal type pipe joint and has high sealing performance.

  A pipe joint according to the present invention includes an inner cylinder part and an outer cylinder part provided with a predetermined gap part for inserting a connected pipe outside the inner cylinder part, and the inner cylinder part has a seal member on the outer periphery. A spring ring is provided on the inner side of the outer cylinder portion and facing the seal member. It is formed.

Pipe joints used for pipe connection include a type in which a male thread or the like is formed on one side of the joint body and pipe connection is made by screwing or the like, and a pipe member such as a resin hose is inserted and connected as a connected pipe on the other side. .
In this type of pipe joint, the present invention is characterized by a structure for inserting a pipe to be connected, and a spring ring is disposed on the inner side of the outer cylinder portion and on the facing portion of the seal member, and the spring ring is connected to the outer peripheral piece portion and the inner peripheral piece portion. Is formed in a double ring having a substantially U-shaped cross section connected on the connected tube insertion side, so that when the connected tube is inserted between the inner peripheral piece portion of the spring ring and the seal member of the inner cylinder portion, The outer periphery of the connected pipe is uniformly pressed by the elastic repulsive force of the inner peripheral piece.

In the present invention, since the spring ring is a U-shaped double ring, there is no need to provide a slit for expanding the diameter as in the prior art, and the repulsive force in the inner circumferential direction of the spring ring can be made uniform.
In addition, since the connecting pipe is inserted so that the connecting portion is bent because the connecting pipe insertion side is connected to the U-shaped cross section, the conventional slit structure requires an enlarged piece, In the present invention, the diameter-expanded piece is not necessarily essential.
In addition, in order to make it easier to insert the pipe to be connected by widening the inner diameter of the inner peripheral piece, and to easily set the repulsive force of the inner peripheral piece, the inner peripheral piece is attached to the pipe joint before connection. You may arrange | position the diameter-expansion guide so that it may spread.
In this case, when the connected pipe is inserted into the insertion port of the pipe joint, the enlarged diameter guide is released from the inner peripheral piece while being pushed by the tip of the connected pipe.
As a result, the inner peripheral piece is elastically restored, the connected pipe is pressed from the outer peripheral side, the blistering of the connected pipe due to the water pressure is suppressed, and the water stoppage by the seal member is improved.

In order to sufficiently exhibit the spring elasticity of the inner peripheral piece of the spring ring, it is preferable to make an incision in the axial direction to form an elastic tooth.
In this way, the diameter can be greatly increased by the diameter expansion guide, and after the diameter expansion guide is removed, the reduction of the inner peripheral circumference can be absorbed by cutting, so that a large repulsive force can be obtained.
For example, if the tip of the elastic tooth has a claw shape with a sharp angle, the elastic tooth can easily bite into the outer periphery of the connected tube. Also become.

  In the present invention, in the inner seal type pipe joint, a substantially U-shape in which a spring ring that presses toward the seal member from the outer peripheral side of the connected pipe is connected to the inner peripheral piece part and the outer peripheral piece part on the connected pipe insertion side. Since it has a shape, it is possible to increase the repulsive force by pressing the outer periphery uniformly and making a cut in the inner peripheral piece as compared with the conventional slit structure, and the effect of preventing slipping is also great.

FIG. 1 shows a cross-sectional view of a main part of a pipe joint according to the present invention.
FIG. 1 (a) shows a state before connection of a pipe to be connected such as a resin hose, and FIG. 1 (b) shows a connection state of the pipe to be connected.
The pipe joint 10a is made of metal, for example, a connection inner thread part formed by forming a cylindrical inner cylinder part 12 in a joint body part 11 made of copper alloy or the like and communicating with the inner cylinder part 12 on the opposite side of the inner cylinder part 12. 14 is provided.
The pipe joint 10 a is connected to the pipe by screwing or the like through the connection male screw portion 14.
The inner cylinder portion 12 is provided with a concave groove 12a, and an O-ring 16 is fitted into the concave groove 12a as a seal member.
And the cylindrical outer cylinder part 13 is attached to the main-body part 11 by screw connection so that the clearance gap part 15 which inserts the to-be-connected pipe | tube 1 may be formed in the cylindrical space outside the inner cylinder part 12. FIG.
The clearance 15 is provided with a transparent cylindrical spacer 17 on the back side viewed from the tube insertion port 18a, and with a spring ring 20 on the front side thereof.
The spring ring 20 is arranged on the inner peripheral surface 13c of the outer cylinder portion on the opposite portion of the O-ring 16.
The gap portion 15 forms a tube insertion portion 18 into which the connected tube 1 is inserted, which leads from the tube insertion port 18 a to the gap between the transparent cylindrical spacer 17 and the inner cylinder portion 12.
An embodiment of the spring ring 20 is shown in FIG.
2 (a), 2 (b), and 2 (c) are a side view, a cross-sectional view, and a perspective view of the state of the spring ring 20 when the connected pipe 1 as shown in FIG. 1 (a) is not connected. 4 (D), FIG. 4 (E), and FIG. 4 (F) show the state of the spring ring 20 when the connected pipe 1 as shown in FIG. 1 (B) is connected.
The spring ring 20 is made of a spring material such as spring steel, and the inner peripheral side and the outer peripheral side of the annular connecting portion 21 are bent at the inner peripheral side edge 21a and the outer peripheral side edge 21b by drawing. Each of the inner peripheral piece portion 21c and the outer peripheral piece portion 21d is formed in a double ring shape and has a substantially U-shaped cross section.
And the notch part 21e of an axial direction is formed in the inner peripheral piece part 21c by shearing etc., and the some elastic tooth 22 is formed equally in the circumferential direction.
When the spring ring 20 is formed by drawing, spring rings of various sizes and thicknesses can be easily formed.
As shown in FIG. 1, the spring ring 20 is attached by being sandwiched between a protruding portion 13 b in which the outer cylindrical portion 13 of the tube insertion port 18 a portion protrudes inward and the transparent cylindrical spacer 17.
When the spring ring 20 is attached, for example, the outer peripheral piece 21b is cut radially to form an elastic piece, and the spring ring is locked to the inner peripheral surface 13c of the outer cylinder part by the elastic force of the elastic piece. It becomes easy to do.
In the unconnected state of the tube 1 to be connected, as shown in FIG. 1 (a), the spring ring 20 is arranged with the connecting portion 21 facing the tube insertion port 18a, and the elastic teeth 22 project obliquely to the tube insertion portion 18, When the elastic teeth 22 are viewed from the insertion port 18a side, a tapered inclined surface 22b is formed.
For this reason, when the connected tube 1 is inserted into the tube insertion portion, the connected tube tip 1b acts to push the elastic teeth 22 outward.
At this time, since the spring ring 20 has a substantially U-shaped cross section, the elastic tooth 22 expands and rides on the outer peripheral surface 1c of the connected pipe so that the connecting portion 21 is bent.
If the tip 22a of the elastic tooth 22 has, for example, a claw shape sharpened at an acute angle, the connected tube 1 can be strongly bitten, so that the connected tube can be strongly locked.
As described above, in the pipe joint of the present invention, the pipe to be connected can be inserted between the spring ring and the seal member without providing a diameter-expanding piece as in the prior art.

FIG. 6 is an explanatory view showing a state in which the spring ring 20 tightens the outer peripheral surface 1 c of the connected pipe 1 toward the O-ring 16.
In FIG. 6, for the sake of clarity, the outer cylinder portion and the like are not shown and only the main portions are drawn.
FIG. 6 (a) shows the unconnected state of the connected pipe, and corresponds to the state of FIG. 1 (a).
The spring ring 20 is added at a position where the axis of the inner tube portion and the spring ring shaft are coaxial so that the tip 1b of the connected tube contacts the inclined surface 22b of the elastic tooth 22 when the connected tube 1 is inserted into the tube insertion portion 18. Are arranged at a position coaxial with the axis of the O-ring 16.
The direction in which the elastic teeth return elastically is the O-ring direction, and the elastic teeth 22 are arranged evenly and circumferentially so that a spring action can be applied toward the O-ring on the connected pipe fitted to the O-ring. Has been established.
When the connected tube 1 is inserted from the tube insertion port, the distal end portion 1b of the connected tube 1 hits the inclined surface 22b of the elastic tooth 22, and when the connected tube 1 is further pushed in, the connected tube distal end 1b elastically moves the elastic tooth 22. The elastic teeth 22 ride on the outer peripheral surface 1c of the connected tube 1 and press the outer peripheral surface 1c of the connected tube 1 with elastic restoring force.
As shown in FIGS. 1B and 6B, the connected state of the pipe 1 to be connected is shown. The elastic teeth 22 apply an equal pressing force in the circumferential direction of the pipe 1 to be connected to the outer peripheral surface 1c of the pipe 1 to be connected. In addition, the inner peripheral surface 1 d of the tube 1 to be connected is pressed toward the O-ring 16.
Moreover, since the insertion state of the to-be-connected pipe | tube 1 can be confirmed seeing through the opening window 13a for confirmation of the outer cylinder part 13 through the transparent cylindrical spacer 17, insertion failure can be prevented.

FIG. 3 is an explanatory view of an embodiment of the pipe joint 10b in the case where the diameter expansion guide 30 is provided.
FIG. 3 (a) shows a state before the connected pipe is connected, and FIG. 3 (b) shows a connected state of the connected pipe.
The clearance 15 is provided with a transparent cylindrical spacer 17 on the back side when viewed from the tube insertion port 18a, and is provided with a spring ring 20 on the front side thereof. In the hole 23 of the spring ring 20 shown in FIG. 30 is fitted.
A perspective view of the enlarged diameter guide 30 is shown in FIG.
The diameter-enlarging guide 30 forms a tube abutting portion 32 by bending an opening end 31a on the back side of a cylindrical spring regulating cylinder portion 31 into a flange shape inside.
The diameter of the spring restricting cylinder portion 31 is such that the connected tube tip end portion 1a can be inserted inside and can be inserted into the tube insertion portion 18 between the transparent cylindrical spacer 17 and the inner cylinder portion 12.

In FIG. 3A, the spring ring 20 has a diameter-expansion guide 30 fitted therein at a position facing the O-ring 16.
As shown in FIG. 3 (a), the diameter-expansion guide 30 has a cylindrical shape as shown in FIG. A cylindrical spring regulating cylinder portion 31 pushes and bends in the outer circumferential direction to regulate the restoring operation, and temporarily holds the elastic teeth 22 outside the tube insertion portion 18.
The state of the spring ring 20 in which the elastic teeth 22 are pushed and expanded by the diameter expanding guide 30 is shown in FIG.
The tube 1 to be connected can be smoothly inserted into the tube insertion portion 18 until the tip of the tube 1 contacts the tube abutting portion 32 of the enlarged diameter guide 30.
Further, when the diameter-enlarged guide 30 is fitted into the spring ring 20 in this way, it is not necessary to spread the elastic teeth 22 by the connected pipe 1, so that the repulsive force of the elastic teeth 22 can be easily set.
When the enlarged diameter guide 30 is provided, the elastic tooth 22 has a large difference in inner peripheral length between the expanded diameter state and the reduced diameter state, but the cut portion 21e between the elastic teeth 22 absorbs this difference.
The spring ring 20 is regulated by the transparent cylindrical spacer 17 to move the inner cylindrical portion 12 in the axially back side. However, the diameter expanding guide 30 has an outer peripheral portion (spring regulating cylindrical portion) 31 of the transparent cylindrical spacer 17. Located on the inner circumference.
For this reason, when the tip 1b of the connected tube 1 pushes the tube abutting portion 32 of the diameter expansion guide 30, the diameter expansion guide 30 is pushed out from the hole 23 of the spring ring 20 to temporarily hold the elastic teeth 22. To release.
FIG. 3B shows a state where the connected pipe 1 pushes the diameter-expansion guide 30 from the spring ring hole 23 and the connected pipe is connected.
The elastic teeth 22 are restored and reduced in diameter toward the inner cylinder portion 12 by the separation of the diameter expansion guide 30 from the spring ring hole 23, and the connected pipe outer peripheral surface 1c is pressed circumferentially by a spring action.
Since the elastic teeth 22 are disposed along the O-ring 16, the inner peripheral surface 1 d of the tube 1 to be connected is pressed toward the O-ring 16, and in the connected state shown in FIG. Water is passed through the connecting pipe, internal pressure is applied to prevent the pipe from bulging, and the inner diameter seal is secured.

FIG. 4 is an explanatory view of an embodiment in which a lock ring for locking the connected pipe is provided in the pipe insertion port.
The pipe joint 10c is attached by screwing a lock nut 40 made of a spring material such as spring steel shown in FIG. .
The lock ring 40 is provided with a ring-shaped inward locking claw 40a on the inner circumference.
The locking claw 40a is inclined toward the back side, and the tip end 40b is bitten into the outer peripheral surface 1c of the connected tube 1 to lock the connected tube 1 as shown in FIG.
FIG. 5 shows an embodiment of a pipe joint provided with both the diameter expanding guide 30 and the lock ring 40.

The explanatory view showing the half section of the example of the pipe joint concerning the present invention, and the outside cylinder part inside is shown. The explanatory diagram of the spring ring state is shown, (a), (b), (c) shows the unloaded shape (d), (e), (f) shows the shape when pressing the outer periphery of the connected pipe. (G) shows the shape when the diameter-expansion guide is fitted inside. Sectional drawing of the Example of the pipe joint provided with the diameter-expansion guide is shown. Sectional drawing of the Example of the pipe joint provided with the lock ring is shown. Sectional drawing of the Example of the pipe joint provided with the lock ring and the diameter-expansion guide is shown. Explanatory drawing of the state which a spring ring clamp | tightens a to-be-connected pipe | tube is shown. (A) indicates a lock ring, and (B) indicates an enlarged diameter guide. An explanatory view of a conventional tightening ring is shown.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Connected pipe 1a Connected pipe front-end | tip part 1b Connected pipe front-end | tip 1c Connected pipe outer peripheral surface 1d Connected pipe inner peripheral surface 10a, 10b, 10c, 10d Pipe joint 11 Joint main-body part 12 Inner cylinder part 12a Concave groove 12b Inside Cylindrical outer peripheral surface 13 Outer cylindrical portion 13a Opening window 13b for confirmation Projecting portion 13c Outer cylindrical inner peripheral surface 14 Male threaded portion 15 for connection Clearance 16 O-ring (seal member)
17 Transparent cylindrical spacer (transparent cover)
18 pipe insertion part 18a pipe insertion port 20 spring ring 21 connection part 21a connection part inner peripheral side edge part 21b connection part outer peripheral side edge part 21c inner peripheral piece part 21d outer peripheral piece part 21e notch part 22 elastic tooth 22a elastic tooth tip 22b elastic tooth inclination Surface 23 Spring ring hole 30 Diameter expansion guide 31 Spring regulation cylinder (expansion guide cylinder)
31a Spring regulating cylinder part opening end 32 Pipe abutting part 32a Pipe abutting part inner edge part 40 Lock ring 40a Locking claw 40b Locking claw tip 41 Cap nut

Claims (3)

An inner cylinder part, and an outer cylinder part provided with a predetermined gap part for inserting the connected pipe outside the inner cylinder part,
The inner cylinder part has a seal member on the outer periphery,
It has a spring ring in the outer cylinder part inside and the opposed part of the seal member,
The spring ring is formed into a double ring having a substantially U-shaped cross section in which an outer peripheral piece and an inner peripheral piece are connected on the connected pipe insertion side.   The pipe joint according to claim 1, wherein an elastic tooth is formed by cutting an inner peripheral piece of the spring ring.   The pipe joint according to claim 1, wherein a diameter-expansion guide is inserted between the inner peripheral piece portion of the spring ring and the seal member of the inner cylinder portion.

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