CN103481514A - Plastic tube butting technology - Google Patents

Abstract

The invention discloses a plastic tube butting technology, and belongs to the technical field of plastic tube processing technologies. The technology mainly comprises the following steps: 1, cleaning the internal surface and the external surface of a plastic tube end; 2, setting a coupling on the external surface of the plastic tube; 3, arranging a support device in the plastic tube; 4, using a flaring device to flare the end of the plastic tube to form a bell mouth; 5, carrying out cooling shaping of the bell mouth, and dismounting the flaring device and the support device; 6, installing a joint at the bell mouth, connecting the coupling with the joint, and compressing the bell mouth between the coupling and the joint; 7, connecting the other end of the plastic tube to a joint through a coupling; and 8, relatively connecting two flange connecting ends. The technology can guarantee that the flow of a butting pipeline is not influenced, can also guarantee that a butting position can bearing enough large radial impact force and axial impact force, and can be widely used in the plastic tube butting.

Description

A kind of plastic pipe interface technology

technical field

The invention relates to a plastic pipe interface technology, which belongs to the technical field of plastic pipe processing technology.

Background technique

In the pipeline transportation industry with slightly higher pressure, such as the high-pressure cleaning machine industry, plastic pipelines are widely used because of their high pressure resistance, corrosion resistance and low cost. However, as the butt joint between pipelines, the electric melting sleeve connection is mainly used at present, and the connection joints of this connection method have the defects of low strength, high cost, slow construction, and non-detachable.

The majority of plastic pipe manufacturers and scientific researchers have also realized the problems of the plastic pipe interface in the prior art, have been looking for better measures and solutions, and have carried out a large number of technical explorations and improvements.

For example, Chinese utility model patent ZL95225570.7 discloses a high-pressure-resistant plastic pipe joint, which is composed of a rubber sealing ring, a threaded female sleeve with grooves, an external threaded sleeve, a gasket and a metal ring with an internal thread. It has a simple structure, The advantages of firm connection and good sealing. However, this interface also has some defects. For example, because the plastic pipe end itself is a cylindrical structure, it can withstand a large enough pressure in the radial direction when it is docked, but the axial pressure resistance impact on the butt joint is very small, causing the joint fall off, causing the plastic pipe joint to fail.

Therefore, for developing a new plastic pipe interface technology, it not only has urgent research value, but also has good economic benefits and industrial application potential, which is the driving force and basis for the completion of the present invention.

Contents of the invention

In order to overcome the defects of the existing plastic pipe interface technology pointed out above, the inventor has conducted in-depth research on this, and after paying a lot of creative work, the present invention has been completed.

Specifically, the technical problem to be solved by the present invention is: to provide a plastic pipe interface technology, which can not only ensure that the flow rate of the butt pipes is not affected, but also ensure that the butt joints can withstand large enough radial impact force and axial impact force .

In order to solve the above technical problems, the technical solution of the present invention is to provide a plastic pipe joint process, the plastic pipe joint process comprising the following steps:

(1) Clean the inner surface and outer surface of the end of the plastic pipe;

(2) Put a collar on the outer surface of the plastic pipe, the collar is provided with a mating end matching the outer diameter of the plastic pipe and a connecting end with an internal thread, the thread diameter of the connecting end is larger than that of the plastic pipe The outer diameter of the connecting end and the mating end is provided with a tapered surface expanding from the mating end to the connecting end;

(3) Place a supporting device for tightening the inner surface of the plastic pipe in the plastic pipe;

(4) Expanding the end of the plastic pipe into a bell mouth with a uniform thickness using a flare device, the bell mouth has an outer surface consistent with the tapered surface of the collar;

(5) After the bell mouth is cooled and shaped, disassemble the flare device and support device;

(6) A joint is installed at the bell mouth, the joint has the same circulation channel as the inner diameter of the plastic pipe, one end of the joint is provided with a support end consistent with the taper of the bell mouth, and the other end of the joint is provided with There is a flange connection end, the joint between the support end and the flange connection end is provided with an external thread suitable for the internal thread of the coupling, the coupling and the joint are connected, and the The bell mouth is pressed tightly between the collar and the joint;

(7) Repeat steps (1)-(6) to connect the end of another plastic pipe with the joint using a collar;

(8) Connect the two flange connection ends oppositely.

In the plastic pipe joint process of the present invention, as an improvement, the support device includes a columnar support body, and the support body is provided with a first slideway extending axially and passing through the support body, so The cross-sectional shape of the first slideway is square, and a slider is slidably installed in the first slideway, and two second slideways that are oppositely arranged and extend radially are arranged on the support body, and the second slideway are all connected to the first slideway, and a contact is slidably installed in each of the second slideways, and one end of the contact is against the slider, and the surface of the slider against the contact is for When the contact is pushed to the wedge-shaped surface of the plastic pipe, the other end protrudes from the support body, and a pressure ring is set on the outer surface of the support body, and the pressure ring is fixedly installed on the support body. The contact protrudes from the pressure ring and a first return spring is provided between the contact and the pressure ring; a first block and a second block are respectively provided at both ends of the first channel, and the first Both the blocking block and the second blocking block are fixedly installed on the support body, and a screw is threaded on the first blocking block, and one end of the screw rod leans against the sliding block, and the other end protrudes from the bell mouth , a second return spring is clamped between the second blocking block and the slider.

In the plastic pipe joint process of the present invention, as a further improvement, an annular protrusion is provided on the end surface of the second blocking block, and the end of the second return spring is sleeved on the annular protrusion.

In the plastic pipe joint process of the present invention, as a further improvement, the flaring device includes a flared inner body and a flared outer body that are connected together, and a horn-shaped flare is formed between the flared inner body and the flared outer body. A cavity, the horn-shaped cavity is surrounded by an inner heating element arranged on the flared inner body and an outer heating element arranged on the flared outer body, and the horn-shaped cavity includes straight sections arranged in sequence The cavity and the horn section cavity, the straight section cavity is adapted to the cross-sectional shape of the plastic pipe, the horn section cavity is adapted to the shape of the horn mouth, and the heating in the horn section cavity The temperature is higher than the heating temperature in the cavity of the straight barrel section, and the end of the cavity of the straight barrel section away from the cavity of the horn section is set as an open; the screw passes through the flared inner body and connects with the flared inner body threaded connection.

In the plastic pipe joint process of the present invention, as a further improvement, the flared outer body includes several outer body monomers in an annular array, and each of the outer body monomers is hingedly mounted on the flared inner body , the outer surface of the flared outer body away from the hinged end is provided with a tightening element for tightening several of the outer body monomers together.

In the plastic pipe interface process of the present invention, as a further improvement, each of the outer body monomers is provided with an outer support part, and the outer support part extends out of the Flared inner body.

In the plastic pipe joint process of the present invention, as a further improvement, the outer support part is integrated with the flared outer body.

In the plastic pipe joint process of the present invention, as another improvement, in step (8), a sealing ring is provided between the two flanges.

After adopting above-mentioned technical scheme, the beneficial effect of the present invention is:

1. Since the end of the plastic pipe is expanded into a bell mouth first, then the bell mouth is tightened with a coupling and a joint, and then the two plastic pipes are connected by a joint, so that the plastic pipe joint can not only bear a large enough radial force Impact force, in the axial direction, compared with the traditional clamped cylindrical end, the bell mouth provides enough protection against impact force, making the plastic pipe joint more firm;

2. Since the inner diameter of the joint is the same as that of the plastic pipe, the flow rate after the plastic pipe joint will not be affected, which ensures the performance of the plastic pipe.

3. Since the flaring device is equipped with heating elements on the flaring inner body and the flaring outer body, different inner and outer heating temperatures can be designed according to the different melting temperatures of plastic pipes, especially those with double-layer components. , to avoid the internal stress of the double-layer plastic pipe when it softens, resulting in the delamination and rupture of the double-layer plastic pipe.

4. Since the flaring outer body is designed as a separate structure, it can be disassembled only by opening the clamping element at the end, which is convenient for use and maintenance.

5. Since there is an outer support part on the outer body, and there is no heating element on the outer support part, when in use, the outer support part can wrap the plastic tube, and the wrapped plastic tube will not be softened and deformed, preventing the The flaring device is not easy to operate when the end of the plastic pipe is softened.

Description of drawings

Fig. 1 is a schematic diagram of the flaring state of a plastic pipe in an embodiment of the present invention;

Fig. 2 is the sectional view of A-A among Fig. 1;

Fig. 3 is a schematic diagram of the state of the plastic pipe interface in the embodiment of the present invention.

Wherein, in FIGS. 1-3 , each numeral signifies the following specific meanings, elements and/or components respectively.

In the figure: 1. flaring inner body, 2. outer body monomer, 3. outer support part, 4. hinge, 5. outer heating element, 6. inner heating element, 7. support body, 8. pressure ring, 9. Slider, 10, first blocking block, 11, second blocking block, 12, second return spring, 13, first return spring, 14, contact, 15, clamping element, 16, collar, 17, connector , 18, sealing ring, 19, plastic pipe, 20, screw rod.

Detailed ways

The present invention will be further described below in conjunction with the accompanying drawings and embodiments. However, the uses and purposes of these exemplary embodiments are only used to illustrate the present invention, and do not constitute any form of limitation to the actual protection scope of the present invention, nor limit the protection scope of the present invention thereto.

Commonly shown in Fig. 1, Fig. 2 and Fig. 3, the present invention provides a kind of plastic pipe joint process, and described plastic pipe joint process mainly comprises the following steps:

(1) cleaning the inner surface and the outer surface of the plastic pipe 19 ends;

(2) A collar 16 is set on the outer surface of the plastic pipe 19. The collar 16 is provided with a mating end compatible with the outer diameter of the plastic pipe 19 and a connecting end with an internal thread. The thread diameter of the connecting end is larger than that of the plastic pipe The outer diameter of 19, a tapered surface expanding from the mating end to the connecting end is provided between the connecting end and the mating end;

(3) Place a support device for tightening the inner surface of the plastic pipe 19 in the plastic pipe 19;

(4) Use a flaring device to expand the end of the plastic pipe 19 into a bell mouth with a uniform thickness, and the bell mouth has an outer surface consistent with the tapered surface of the collar 16;

(5) After the bell mouth is cooled and shaped, disassemble the flare device and support device;

(6) A joint 17 is installed at the bell mouth. The joint 17 has the same circulation channel as the inner diameter of the plastic pipe 19. One end of the joint 17 is provided with a support end consistent with the taper of the bell mouth, and the other end of the joint 17 is provided with a flange connection end. , the joint 17 between the support end and the flange connection end is provided with an external thread that matches the internal thread of the coupling 16, connects the coupling 16 and the joint 17, and presses the bell mouth tightly on the coupling 16 and the joint 17 between;

(7) Steps (1)-(6) are repeated, and another plastic pipe end is also connected together with the coupling 16 and the joint 17;

(8) The two flange connection ends are relatively connected together, and a sealing ring 18 is arranged between the two flanges. The sealing ring 18 is preferably a metal graphite wound gasket. When the interface distance is different, the sealing ring 18 can be adjusted. The number of layers is different to adapt to the connection firmness and sealing of the two plastic pipes.

Of course, some flaring devices have also been disclosed in previous patent documents, but the inventor has paid a huge amount of creative work and developed a more suitable device by himself, which is used to realize the flaring of the plastic pipe 19, especially for The double-layer plastic pipe commonly used at present, because two-layer inside and outside the double-layer plastic pipe has different components, its softening temperature is different, if adopt same kind of temperature to control the softening of plastic pipe 19 ends, then there will be double-layer plastic pipe in combination. Layers produce internal stress, resulting in delamination or rupture, affecting the normal use of the plastic pipe 19.

Before the end of the plastic pipe 19 is softened, a supporting device is first placed in the plastic pipe 19. The first purpose is to increase the rigidity of the plastic pipe 19 to avoid deformation of the end of the plastic pipe 19 during the operation. The mouth device is a point of leverage. For the above two purposes, the structure of the support device used by the inventor has also been carefully studied, and the traditional concept of using a backing ring as a support has been changed. The support device of the present invention includes a columnar support body 7, and the support body 7 is provided with Axially extending and passing through the first slideway of the support body 7, the cross-sectional shape of the first slideway is square, and a slider 9 is slidably installed in the first slideway, and the support body 7 is provided with two oppositely arranged and radially extending The second slideway, the second slideway is connected to the first slideway, and the contact 14 is slidably installed in each second slideway, one end of the contact 14 is against the slider 9, and the surface of the slide block 9 and the contact 14 is against For pushing the contact 14 to the wedge-shaped surface of the plastic pipe 19, the other end protrudes from the support body 7, the outer surface of the support body 7 is covered with a pressure ring 8, the pressure ring 8 is fixedly installed on the support body 7, the contact 14 Stretch out pressure ring 8 and be provided with first return spring 13 between contact 14 and pressure ring 8; The second blocking block 11 is all fixedly installed on the support body 7, and a screw rod 20 is threaded on the first blocking block 10, and one end of the screw rod 20 leans against the slide block 9, and the other end stretches out from the bell mouth, and the second blocking block 11 and A second return spring 12 is clamped between the sliders 9 , an annular protrusion is provided on the end surface of the second blocking block 11 , and the end of the second return spring 12 is sleeved on the annular protrusion. The assembled support body 7 is placed in the plastic tube 19, the screw rod 20 extends out of the end of the plastic tube 19, the screw rod 20 is rotated, the contact 14 stretches out, and the inner wall of the plastic tube 19 is tightened. At this time, the contact 14 cannot apply too much force. Large, to avoid deformation of the plastic pipe 19, after the outer support part 3 is supported at the position of the plastic pipe 19, continue to rotate the screw 20, and the contact 14 will tighten the plastic pipe 19.

The flaring device includes a flaring inner body 1 and a flaring outer body connected together, a flared cavity is formed between the flared inner body 1 and the flared outer body, and an inner cavity arranged on the flared inner body 1 is arranged around the flared cavity. The heating element 6 and the outer heating element 5 arranged on the flared outer body, the trumpet-shaped cavity includes a straight cylinder section cavity and a horn section cavity arranged in sequence, the straight cylinder section mold cavity is adapted to the cross-sectional shape of the plastic pipe 19, and the horn Section die cavity and the shape of bell mouth are adapted, and the heating temperature in the horn segment die cavity is higher than the heating temperature in the straight tube segment die cavity, usually, the heating temperature of straight tube segment die cavity is lower than the melting temperature of plastic pipe 19, and The heating temperature of the horn section cavity is between the melting temperature and the decomposition temperature of the plastic pipe 19, and the end of the straight tube section cavity away from the horn section cavity is set as an open opening; the screw rod 20 passes through the flared inner body 1 and is connected with the flared inner body 1 threaded connection. When in use, first insert the end of the plastic tube 19 into the cavity of the straight section to soften the end, turn the flaring inner body 1, the flaring inner body 1 moves toward the support body 7, and introduce the softened plastic tube 19 into the horn segment cavity , and melt in this cavity, the inner heating element 6 and the outer heating element 5 around the cavity of the straight barrel section and the horn section are controlled separately. In the melting stage of the plastic pipe 19, the inner heating element 6 around the cavity of the straight barrel section And the external heating element 5 is no longer continue to heat, adopt this flaring way, overcome the defect that the wall thickness of the plastic pipe is thinned after the traditional flaring device flaring causes the plastic pipe strength to reduce. Usually, both the inner heating element 6 and the outer heating element 5 use electric heating wires, and of course other methods such as high-pressure steam can also be used.

If the plastic pipe 19 is a double-layer plastic pipe, the flaring device can better reflect its use value. When in use, during the softening process of the plastic pipe, the heating temperature of the inner heating element 6 corresponds to the melting temperature of the inner layer of the plastic pipe, and the heating temperature of the outer heating element 5 corresponds to the melting temperature of the outer layer of the plastic pipe, and the two layers of plastic pipes are softened simultaneously , to avoid the internal stress in the softening stage.

The flared outer body includes a number of outer body monomers 2 in an annular array, and each outer body monomer 2 is hingedly mounted on the flared inner body 1 through a separate hinge 4, and the outer surface of the flared outer body away from the hinged end is provided with a plurality of outer body The tightening element 15 for tightening the monomers 2 together, the tightening element 15 can use a hoop or an end-to-end annular tension spring. With the flared outer body in this way, the outer heating element 5 is generally arranged not in a surrounding arrangement, but along the extension direction of the outer body monomer 2, so that it is not necessary to reassemble and disassemble the outer heating element during disassembly and assembly. 5. Further save maintenance time.

Similarly, the flaring device can also be designed in other forms, for example, the outer body monomer 2 is connected to the flaring inner body 1 through fasteners, but this operation is a little complicated, and disassembly and installation are time-consuming and laborious.

As another ingenious idea of the present invention, each outer body monomer 2 is provided with an outer support part 3, and the outer support part 3 extends out of the flared inner body 1 away from the direction of the trumpet-shaped cavity, and the outer support part 3 and the flared outer body Set as a whole, the outer support part 3 not only played the supporting role before the softening of the plastic pipe 19, but after the plastic tube 19 softened, when the flared inner body 1 was rotated, the outer support part 3 also played a holding role, and the outer support part 3 would harden Quality plastic pipe 19 wraps up, has provided enough supporting force. For the convenience of installation and use, the tightening element 15 is installed at the end of the outer support part 3 .

It should be understood that these examples are only used to illustrate the present invention and are not intended to limit the protection scope of the present invention. In addition, it should also be understood that after reading the technical content of the present invention, those skilled in the art can make various changes, modifications and/or variations to the present invention, and all these equivalent forms also fall within the appended claims of the present application. within the defined scope of protection.

Claims (8)

1. a plastics pipe interface technique, is characterized in that, described technique comprises the following steps:

(1) clean inner surface and the outer surface of end of plastic tube;

(2) be set with a box cupling at the plastic tube outer surface, described box cupling be provided with one with suitable abutting end and the link with internal thread of plastic tube external diameter, the screw thread latus rectum of described link is greater than the external diameter of plastic tube, is provided with the conical surface to described link expansion by described abutting end between described link and abutting end;

(3) place a bracing or strutting arrangement for stretching plastic tube inner surface in plastic tube;

(4) use expanding device end of plastic tube to be expanded into to the horn mouth of an even thickness, described horn mouth has the outer surface consistent with the conical surface of described box cupling;

(5) after described horn mouth cooling and shaping, dismantle described expanding device and bracing or strutting arrangement;

(6) at described horn mouth place, one joint is installed, described joint has the circulation passage identical with the plastic tube internal diameter, described joint one end is provided with the support end consistent with described horn mouth tapering, the described joint other end is provided with flanged ends, be provided with the external screw thread suitable with described coupling inner thread on the described joint between described support end and flanged ends, connect described box cupling and joint, described horn mouth is pressed between described box cupling and joint.

(7) repeating step (1)-(6), also used box cupling and joint to link together another end of plastic tube;

(8) two flanged ends are linked together relatively.

2. plastics pipe interface technique as claimed in claim 1, it is characterized in that: described bracing or strutting arrangement comprises the supporter of column, described supporter is provided with the first slideway that extends axially and run through described supporter, the cross sectional shape of described the first slideway is square, be slidably fitted with slide block in described the first slideway, described supporter is provided with two the second slideways that are oppositely arranged and radially extend, described the second slideway all is communicated with described the first slideway, all be slidably fitted with contact in every described second slideway, described contact one end and described slide block offset, the surface that described slide block and described contact offset is for described contact being pushed to the lozenges of plastic tube, the other end stretches out described supporter, the outer surface of described supporter is set with a pressure ring, described pressure ring is fixedly installed on described supporter, described contact stretches out between described pressure ring and described contact and pressure ring and is provided with the first back-moving spring, the two ends of described first passage are respectively equipped with the first sprue and the second sprue, described the first sprue and the second sprue all are fixedly mounted on described supporter, a screw rod is threaded on described the first sprue, described screw rod one end relies on described slide block, the other end stretches out described horn mouth, between described the second sprue and slide block, is clamped with the second back-moving spring.

3. plastics pipe interface technique as claimed in claim 2, it is characterized in that: the end face of described the second sprue is provided with an annular protrusion, and the end of described the second back-moving spring is set on described annular protrusion.

4. as claim 1 or 2 or 3 described plastics pipe interface techniques, it is characterized in that: described expanding device comprises enlarging endosome and the enlarging ectosome linked together, form a tubaeform die cavity between described enlarging endosome and enlarging ectosome, be provided with the interior heating element heater be arranged on described enlarging endosome around described tubaeform die cavity and be arranged at the external heat element on described enlarging ectosome, described tubaeform die cavity comprises direct tube section die cavity and the loudspeaker segment type chamber set gradually, the cross sectional shape of described direct tube section die cavity and plastic tube is suitable, described loudspeaker segment type chamber and described bell-mouthed shape are suitable, heating-up temperature in described loudspeaker segment type chamber is higher than the heating-up temperature in described direct tube section die cavity, described direct tube section die cavity is set to uncovered away from an end in described loudspeaker segment type chamber, described screw rod passes described enlarging endosome and is threaded with described enlarging endosome.

5. plastics pipe interface technique as claimed in claim 4, it is characterized in that: described enlarging ectosome comprises some ectosome monomers of annular array, each described ectosome monomer is hinged being installed on described enlarging endosome all, and described enlarging ectosome is provided with some described ectosome monomer bandings banding element together away from the outer surface of hinged end.

6. plastics pipe interface technique as claimed in claim 5 is characterized in that: be equipped with an outer support section on each described ectosome monomer, described outer support section deviates from described tubaeform die cavity direction and extends described enlarging endosome.

7. plastics pipe interface technique as claimed in claim 6, it is characterized in that: described outer support section and described enlarging ectosome are set to one.

8. plastics pipe interface technique as claimed in claim 1, is characterized in that: in step (8), between two flanges, be provided with sealing ring.

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