JPH0893975A - Flareless type tube fitting - Google Patents

Abstract

PURPOSE: To improve the strength of the biting projection of a dropping-out preventing tool by providing a circular theft part in the corner angle part between the diameter contracted surface on a joint body side and the dropping-out preventing tool inner surface, and dispersing a stress to the whole projection, when a large force is added to the foot part of the projection, without collecting the stress to the foot part. CONSTITUTION: The joint body 20 consisting of forgeable cast iron material of a tube fitting for polyethylene tube connection has a male screw 21 on the end part outside, and a push ring 30 having integrally having an inward collar 32 is screwed to it. A packing 40 is installed between the packing chamber 22 of the joint body 20 and a pipe 7 inserted thereto, and this packing 40 holds the outer surface of the connecting pipe 7 in cooperation with a dropping-out preventing tool 60 the diameter of which is contracted by the tapered inner surface 33 of the push ring 30. This dropping-out preventing tool 60 has three biting projection streaks 62 formed on the inner circumferential side, and a circular theft part 65 is provided in the corner angle part between the diameter contracted surface 64 of the projection 62 and the dropping-out preventing tool inner surface 63, whereby a stress added to the projection foot part is dispersed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bite type pipe joint using a retainer having a saw-toothed bite protrusion on its inner surface and having a substantially triangular cross section.

[0002]

2. Description of the Related Art Conventionally, there is a pipe joint shown in FIGS. 3 and 4 disclosed in Japanese Utility Model Publication No. 56-166387. In this product, a rubber packing 9, a washer 10 and a pipe stopper 15 are attached to the joint body 1, and the biting projection 14 of the pipe stopper 15 is fitted on the inner peripheral inclined surface 5 of the cap nut 6 and the outer peripheral surface of the connecting pipe 7. The rubber packing 15 is pushed in and sealed while it is bitten into 8.

[0003]

In the conventional bite type pipe joint described above, when the cap nut 6 is fastened to the joint body 1 or when an excessive pulling force is applied to the pipe 7 after being fastened to the pipe 7. , The stress is not evenly distributed over the entire biting protrusion 14 of the pipe removal stopper 15, and the stress concentrates at the root of the biting protrusion 14, and if excessive force is applied, a part of the biting protrusion may be broken or fatigued. The entire depth of the protrusion 14 does not effectively cut into the outer peripheral surface of the pipe, and when a pulling force is applied to the pipe, the pipe 7 slides between the outer peripheral surface of the pipe and the pipe 7 pulls out from the joint body 1. was there.

In this phenomenon, if the root width of the protrusion is increased to increase the strength of the biting protrusion, the biting angle becomes large, so that it becomes difficult to bite into the outer peripheral surface of the pipe, and conversely, when the biting angle is made smaller so as to facilitate the biting. Since the base width of the protrusion is reduced, the strength of the bite protrusion is weakened and the protrusion is easily broken. The present invention solves the above-mentioned problems, and it is possible to obtain a biting protrusion having a size and shape that can surely bite into the outer peripheral surface of the pipe, and a biting protrusion with high strength, and thus a biting with which a large holding force for the pipe is obtained. Provided is a pipe joint.

[0005]

DISCLOSURE OF THE INVENTION The gist of the present invention is to provide a joint main body having an enlarged diameter portion on the inner surface of an end portion, and insert one end of a pipe into the joint main body so as to provide a space between the outer surface of the pipe and the inner surface of the enlarged diameter portion. In a pipe joint consisting of a mounted packing, a push ring having a tapered inner surface that narrows toward the end on the inner surface, and a retainer that is mounted between the tapered inner surface of the push ring and the outer surface of the pipe to hold the pipe, The retainer has a cross section having an inclined surface pushed by the tapered inner surface of the push ring on the outer circumference, a plurality of biting protrusions protruding from the inner surface on the inner circumference and biting into the outer surface of the pipe, and a slit on a part of the circumference. Is a substantially C-shaped expanding and contracting diameter, and an arc-shaped recess having a diameter slightly larger than the inner surface is provided at the corner between the inner surface and the reducing surface on the joint body side of the biting protrusion. It is a characteristic bite type pipe joint. In the above, the retainer is made of resin or copper alloy.

[0006]

Since the present invention has the above-mentioned structure, the biting protrusion of the retainer is formed by the arcuate recessed portion provided at the corner between the reduced diameter surface on the joint body side and the inner surface of the retainer. Even when a large force is applied to the root portion, the stress is not concentrated on the root portion and the stress is dispersed over the entire protrusion, so that the strength of the protrusion increases. Therefore, it is possible to provide a protrusion having a small biting angle shape that easily bites into the surface of the tube. Moreover, since the inner diameter of the sunk portion is slightly larger than the inner surface of the retainer, the biting protrusion deeply digs into the outer peripheral surface of the pipe. Therefore, the height of the biting protrusion effectively acts as a holding force for the tube, and a large pull-out strength with respect to the tube is obtained.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the bite type pipe joint of the present invention will be described below with reference to FIGS. 1 and 2 by taking a pipe joint for connecting a polyethylene pipe as an example. FIG. 1 is a partial cross-sectional view of a joint end portion showing a state after pipe connection. Reference numeral 20 denotes a joint body made of a malleable cast iron material, which has an external thread 21 for coupling with a push ring on the outer surface of the end portion, and an inner surface having a surface which expands toward the end portion for accommodating packing. It has a packing chamber 22. Reference numeral 30 denotes a push ring made of a malleable cast iron material or the like, which has an internal thread 31 for coupling with the joint main body on the inner surface thereof, and subsequently has a collar 32. The inner surface of the collar 32 has a tapered inner surface 33 that narrows toward the end side, and the angle of the tapered inner surface 33 is set to 30 degrees on one side.

A packing 40 made of synthetic rubber is provided between the packing chamber 22 of the joint body 20 and the pipe 7 inserted therein.
When the packing 40 is axially pressed from the end side, the packing 40 is compressed between the packing chamber 21 and the outer surface of the pipe 7 to perform a sealing action. 50 is an annular collar made of a synthetic resin material, which has a surface for compressing the packing toward the joint body,
The opposite end side has a surface pressed against the joint body side 20 by the retaining member 60.

Reference numeral 60 denotes a retainer for reducing the diameter by the tapered inner surface 33 of the push ring 30 and holding the outer surface of the connecting pipe 7, which is a C-shaped member having a notch in an annular portion and made of hard resin such as polyacetal or copper. Made of alloy. FIG. 2 is an enlarged cross-sectional view of the main part thereof. The outer surface has an inclined surface 61 with an inclination angle of 30 degrees that engages with the tapered inner surface 33 of the push wheel, and the bite protrusion 62 protruding from the inner surface 63 on the inner peripheral side. There are 3 articles. An arc 6 having a radius r, which is slightly larger than the inner surface 63, is formed at a corner portion between the joint body side reduced diameter surface 64 of the projection 62 and the retaining surface inner surface 63.
A dull portion 65 connected by 6 is provided. In this way, since the root of the protrusion 62 is arcuate and is recessed from the inner surface 63, the protrusion 62 protruding from the inner surface 63 can deeply penetrate into the pipe 7, and the root of the protrusion 62 is arcuate. Since the stress applied to the projection is not concentrated at the root portion but is distributed over the entire area, a large strength of the projection can be obtained.

When the push ring 30 is fastened to the joint body 20,
Since the retaining member 60 that engages with the tapered inner surface 33 of the push wheel 30 has a reduced diameter, the biting protrusion 62 of the retaining member 60 bites into the outer surface of the pipe 7 as shown in FIG. Press in the direction. As a result, the sealing action between the pipe 7 and the joint body 20 is achieved, and the stopper 60
The tube is held by the biting into the tube, and the tube 7 is prevented from coming off.

Further, after fastening with the pipe 7, even if a large pulling force is applied to the pipe 7, the corners of the root of the biting protrusion are connected with the arc 66 having a radius r slightly larger than the inner surface 63. Since the portion 65 is provided, the protrusion 62
It is possible to deeply dig into the surface of the tube 7 at all of the protruding height thereof, and together with the projection 62 having a large strength connected by the arc 66, it is possible to hold the tube 7 with a large force.

[0012]

As described above, the bite type pipe joint of the present invention is a bite type pipe joint that surely bites into a pipe and can obtain a large holding force with respect to the pipe.

[Brief description of drawings]

FIG. 1 is a sectional view of an essential part of a joint end portion showing an embodiment of the present invention.

FIG. 2 is an enlarged cross-sectional view of a main part of the retainer of FIG.

FIG. 3 is a cross-sectional view of a main part of a joint end portion showing a conventional technique.

FIG. 4 is an enlarged cross-sectional view of a main part of the retainer of FIG.

[Explanation of symbols]

20 Joint Body 21 Male Thread 22 Packing Chamber 30 Push Ring 31 Female Thread 32 Collar 33 Tapered Inner Surface 40 Packing 50 Collar 60 Detachment Tool 61 Inclined Surface 62 Biting Protrusion 63 Inner Surface 64 Reduced Surface of Projection 65 Recessed Part 66 Arc

Claims (1)

[Claims] 1. A joint body having an enlarged diameter portion on an inner surface of an end portion,
One end of the pipe is inserted into this joint body, and the packing is attached between the outer surface of the pipe and the inner surface of the expanded portion, the push ring having a tapered inner surface that narrows toward the end on the inner surface, and the taper inner surface of the push ring and the pipe. In a pipe joint consisting of a retaining device that is mounted between the outer surface and a grip to hold the pipe, the retaining device has an inclined surface that is pushed by the tapered inner surface of the push ring on the outer periphery and a pipe protruding from the inner surface on the inner periphery. The cross-section having a plurality of biting protrusions that bite into the outer surface and a cut on the circumference is a substantially C-shaped C ring shape that expands and contracts, and the inner surface and the diameter-reduced surface on the joint body side of the biting protrusion A bite type pipe joint characterized in that an arcuate recessed portion having a diameter slightly larger than the inner surface is provided in a corner portion.