CN2167257Y

CN2167257Y - Joint for plastic pipe

Info

Publication number: CN2167257Y
Application number: CN 93221049
Authority: CN
Inventors: 高洄荣; 姜南一; 韩奇洞
Original assignee: Yukong Ltd
Current assignee: Yukong Ltd
Priority date: 1993-08-04
Filing date: 1993-08-04
Publication date: 1994-06-01
Anticipated expiration: 2003-08-04

Abstract

The utility model relates to a joint for plastic pipes. The utility model can keep uniform sealing ability no mater how the pipe is deformed because of temperature change and aging. The utility model comprises a joint body with external screw threads. The joint body is provided with an inserting part which prepares to be inserted into the pipe, a brass sleeve ring used for sheathing on the inserting part and contacting with one end surface of the joint body, and a tightening screw nut with internal screw threads in order to engaged with the external screw threads of the joint body. A plurality of annular grooves with rectangular sections are formed on the external surface of the inserting part of the joint body, and rubber O-shaped rings are arranged in the annular grooves.

Description

Joint for plastic pipe

The present invention relates to connect the pipe joint of the pipe joint of plastic tube, particularly this plastic tube, it can keep uniform sealability, though pipe owing to variation of temperature and aging be out of shape also unaffected.

In general, plastic pipe since its tubulature cost low and be easy to the assembling and be used for various machines and pipeline at large.As one of above-mentioned conventional pipe fitting, the joint of the polyethylene pipe of making according to Korea S standard K S B1564 comprises a fittings body, the tightening nut and a brass collar (brass slite olive).But this pipe joint is along with its sealing force of process of using reduces gradually.

More particularly, because this pipe joint of making according to Korea S standard K S B1564 is to be contained in by this way on the pipe, be that fittings body is inserted in the pipe with its insertion portion, tightening nut then is bonded on the fittings body, the brass collar then is between the solid and fittings body of fastening screw, the leakage of fluid can take place between fittings body and pipe, because pipe can and agingly expand or tightens because of variation of temperature.

The present invention makes in view of the problems referred to above that take place in the prior art pipe joint, its objective is to plastic pipe a kind of pipe joint is provided, this pipe joint has the RUBBER O shape ring on a plurality of outer annulus edgies that are installed in its insertion portion, thereby the sealability between pipe joint and the pipe fitting is improved, and also is prevented by variation of temperature and the aging escape of liquid that causes.

According to the present invention, above-mentioned purpose is reached so that a kind of like this pipe joint that is used for plastic pipe to be provided, this pipe joint comprises a fittings body, fittings body has an outside thread and preparation at the one end and is inserted into insertion portion in the pipe in its end, on the insertion portion that is enclosed within the fittings body that has a pipe and with the contacted brass collar of the end face of fittings body, this pipe is between the insertion portion and the brass collar, with a tightening nut with internal thread, the outside thread engagement of its internal thread and fittings body, and the brass collar is between tightening nut and the fittings body, the insertion portion of described fittings body is formed with many annular grooves with rectangular cross section on its outer surface, and RUBBER O shape ring is housed in the annular groove.

More shape is clear after having seen following detailed description and accompanying drawing for these and other objects of the present invention, feature and advantage, wherein:

Fig. 1 is an exploded view according to plastic pipe pipe joint of the present invention, has wherein made broken section;

Fig. 2 a is a partial sectional view of preparing to install to a pipe joint of the present invention on the pipe;

Fig. 2 b is the view that is similar to Fig. 2 a, and wherein pipe joint installs on pipe.

Below with reference to accompanying drawings plastic pipe pipe joint of the present invention is described.

Referring to Fig. 1, the figure shows the pipe joint of a plastic pipe of the present invention. As shown in FIG., pipe joint 1 comprises a fittings body 2, this fittings body has a preparation and is inserted into insertion portion 6 in the plastic tube 11, preparation be contained on the pipe 11 and with the fittings body 2 contacted brass collars 4, with the clamp nut 3 that a preparation is meshed with fittings body 2 with screw thread, the brass collar is between fittings body 2 and clamp nut 3.

More particularly, be formed with internal thread 7 on the outer surface that fittings body 2 is held within it, and the outer surface in its outer end is formed with external screw thread 8. Also have, fittings body 2 also is formed with the surface 9 of a taper within it on the end surfaces.

The external diameter of insertion portion 6 is identical with the internal diameter of the plastic tube of preparing to be connected 11, and is formed with the groove 6a of annular on its outer surface.A plurality of RUBBER O shape rings 5 are assemblied in the annular groove 6a., though be formed with three annular groove 6a on the shown insertion portion 6, have only two RUBBER O shapes ring 5 to be assembled in the annular groove 6a here, promptly the inside and outmost groove 6a respectively dispose a RUBBER O shape ring 5, and middle groove 6a does not dispose.

Therefore, when pipe joint 1 installs on the plastic tube 11, the inner surface portion that of plastic tube 11 is equivalent to the intermediate groove position owing to the brass collar 4 radially inwardly compressive force be embedded in the intermediate groove 6a, thereby prevented that plastic tube 11 and insertion portion 6 from separating.In addition, because the cross section of annular groove 6a is rectangular, RUBBER O shape ring 5 can be out of shape and be embedded in the annular groove 6a, to be obedient to the rectangular shape of groove 6a.Therefore, when the insertion portion 6 of pipe joint 1 is inserted into when going in the pipe 11 and therefrom transfering to, RUBBER O shape ring 5 can't separate with groove 6a, even and if the radially compression of inside compressive force that is subjected to the brass collar 4 of insertion portion and pipe can not rupture yet.

Above-mentioned fittings body 2 of the present invention can be used for various pipe coupling spares, for example in leading pipe box, pipe union, three-way pipe, union reducer (CONCENTRIC REDUCER) or the like, thereby it can be connected on another pipe coupling or the fixing machine.

The brass collar 4 that preparation is placed between fittings body 2 and the tightening nut 3 is formed with conical surface 4a on the circle edge of its opposite end.Be equivalent to the conical surface 9 of fittings body 2 one of among the conical surface 4a, another then is equivalent to the conical surface 3b of back with the tightening nut 3 of narration.In addition, the brass collar 4 has interior annular excrescence 4b on the surface within it.

Be formed with internal thread 3a on the internal surface of tightening nut 3, and on the internal surface of its outer end, be formed with the conical surface 3b of another conical surface 4a that is equivalent to the brass collar 4.

Therefore, when tightening nut 3 engage with fittings body 2 so that nut 3 and fittings body 2 mutually near the time, the brass collar 4 is subjected to conical surface 4a, slip effect between the conical surface 9 of fittings body 2 and the conical surface 3b of nut 3 and radially inwardly being compressed is so that plastic tube 11 is pressed on the insertion portion 6 of fittings body 2.Therefore, pipe 11 just has been connected on the pipe joint 1 securely.

The operational circumstances of pipe joint of the present invention will be described below.

Fig. 2 a illustrates pipe joint of the present invention, and this pipe joint is prepared to be connected on the pipe, and Fig. 2 b illustrates pipe joint and is connected on the pipe fully.

As shown in FIG., for pipe joint 1 is connected on the pipe 11, the tightening nut 3 and the brass collar 4 at first are enclosed within on the termination of pipe 11, and fittings body 2 is inserted in the termination of pipe 11 with its insertion portion 6 then.Subsequently, two spanners of tightening nut 3 usefulness are engaged on the fittings body 2.At this moment, as previously mentioned, the brass collar 4 radially inwardly is pressed on the conical surface 9 and 3b of fittings body 2 and tightening nut 3.Therefore, the internal surface of pipe 11 closely contacts on the outer surface of insertion portion 6, and RUBBER O shape ring 5 is arranged between two surfaces, thereby, even produce the crack because of temperature variation with wearing out between pipe joint 1 and the pipe 11, the flow through fluid of fittings body 2 and pipe 11 as air, liquid line, can therefrom not leak out yet.

In addition, pipe 11 can't separate with fittings body 2, because on the outer surface of interior annular excrescence 4b attached to pipe 11 of the brass collar 4, and a part of internal surface of pipe 11 is embedded in the intermediate groove 6a of insertion portion 6 because of inside compressive force.

From top narration, can find out significantly, because joint for plastic tube of the present invention is made into to be formed with many annular grooves on the insertion portion of its fittings body, and flexible RUBBER O shape ring is contained in those annular grooves, and this pipe joint just can prevent because of temperature variation and the aging fluid leakage that causes by the flexible of RUBBER O shape ring.

In order to understand the present invention better, will provide some concrete examples and comparative example below and be illustrated, but these examples and not meaning that limit the scope of the invention by its distinctive embodiment.

Example 1

Make as shown in fig. 1 20 pipe joints that can connect pipe according to the present invention with brass material, its external diameter is 16mm.These pipe joints are connected the two ends of the plastic tube of long 30cm, and a side of plastic tube clogs with chock plug, so just is ready to 20 test blocks.Another side of pipe is connected respectively on the hydroscope.Ten in the test block at 60Kgf/cm ²Hydraulic pressure under with (20 ± 3 ℃) room temperature water test ten minutes, and ten other test blocks are at 40Kgf/cm ²Hydraulic pressure under with the high-temperature water of (80 ± 3 ℃) test ten minutes.Then, test block is checked the rhegma of its pipe joint and pipe and the leakage situation of water.Test result sees Table 1.

In this example, used the metal tube (its trade mark is " YUGONG KITEC PIPE COR 12 ", and it is made by Korea S Yugong Co., Ltd) that scribbles plastics, its manufacture method is published on No. the 0024220th, European patent.

Example 2

Make ten pipe joints and they are connected the two ends of the long pipe of five 4m in the mode similar, be ready to five test blocks like this to example 1.With temperature be 95 ± 3 ℃ water and temperature be 18 ± 3 ℃ water at 10Kgf/cm ²Hydraulic pressure under every 15 minutes test block alternately and is repeatedly tested.Then test block is checked the rhegma of its pipe joint and pipe and the leakage of water (heat cycle test).Test result sees Table 2.

Comparative example 1

According to 20 pipe joints (this joint is on sale on the market) that Korea S mark standard K S B1564 makes, identical in its diameter and the example 1.These joints detect with method identical in the example 1, and its test result sees Table 1.

In this example, be the pipe joint of making by Korea S Namsung Precision Industry Company (12A) according to Korea S's made pipe joint of standard K S B1564.

Comparative example 2

Ten used pipe joints are prepared with method same in the example 2 and are detected in comparative example 1.Its test result sees Table 2.

Table 1

Instance number	20±3℃	80±3℃
			Example 1	None seepage in ten samples	None seepage in ten samples
Comparative example 1	None leakage loss in ten samples	Do not have leakage loss in three samples, but find leakage loss in 7 samples

Table 2

Instance number	Repetitive cycling	Time
			Example 2	None leakage loss circulates for 3000 times	1500 hours
Comparative example 2	Average 8 circulations just have leakage loss	4 hours

Note, repetitive cycling: 18 ± 3 ℃ (15 minutes) → 95 ± 3 ℃ (15 minutes)→ 18 ± 3 ℃ (15 minutes) → 1 circulation (30 minutes)

Claims

1, a kind of pipe joint that is used for plastic pipe, it is characterized in that: it comprises a fittings body, fittings body has an outside thread and preparation at the one end and is inserted into insertion portion in the pipe in its end, on the insertion portion that is enclosed within the fittings body that has a pipe and with the contacted brass collar of the end face of fittings body, this pipe is between the insertion portion and the brass collar, with a tightening nut with internal thread, its internal thread is meshed with the outside thread of fittings body, and the brass collar is between tightening nut and the fittings body, the insertion portion of described fittings body is formed with many annular grooves on its outer surface, and rubber 0 shape ring is housed in the annular groove.

2, pipe joint according to claim 1 is characterized in that described annular groove has rectangular cross section.