A plastic corrugated pipe joint for prestress and its installation method

Abstract

The present invention provides a plastic corrugated pipe joint for prestress and its installation method, including a joint body. Both ends of the joint body are respectively connected to two plastic corrugated pipe sections for prestress. It also includes a heat shrinkable sleeve and a sealing ring. The heat shrinkable sleeve is wrapped around the outer circumference of the joint body and extends to wrap the outer wall of the plastic corrugated pipe section. The inner wall of the joint body that cooperates with the plastic corrugated pipe section is arranged as a conical structure with a gradually decreasing diameter from shallow to deep. The structure and installation method of the present invention are simple. While being able to solve the problem of pipe sealing, it also makes the connection part have a certain flexibility, greatly improving the connection quality of the plastic corrugated pipes for prestress, being more in line with the application of actual working conditions, and providing a basic guarantee for the electrical monitoring of the prestressed steel strands in the pipes.

Description

Technical Field

[0001] The invention belongs to the field of prestressed construction, and relates to a plastic corrugated pipe joint for prestress and an installation method thereof. Background Art

[0002] The corrugated pipes for prestress are mainly divided into two categories: one is the metal corrugated pipe, and the other is the plastic corrugated pipe. The metal corrugated pipe is made of metal steel strip as the raw material through the processes of winding and pressing forming, and its sealing performance and corrosion resistance are lacking. The plastic corrugated pipe is formed by one-time extrusion molding through a mold, with good water tightness and air tightness. The formed closed space not only improves the durability of the prestressed tendons in the pipeline, but also provides conditions for the electrical monitoring of the prestressed steel bundles. The friction coefficient of the plastic corrugated pipe is lower than that of the metal corrugated pipe, reducing the friction loss of the prestressed tendon during the stress process. Therefore, the application of the plastic corrugated pipe has a positive promoting effect on improving the prestressed pipeline technology. When applying the plastic corrugated pipe to form a closed space, the connection problem between two pipes needs to be solved, and it is necessary to ensure that the connection node also has good tightness.

[0003] In the prior art, there are already many structures of corrugated pipe connection nodes. For example, a circular pipe seal joint for connecting a bamboo joint-shaped prestressed plastic pipe with an exhaust pipe disclosed in Chinese Patent CN205136927U is composed of a first semi-circular pipe and a second semi-circular pipe butt-jointed; there is an exhaust pipe on the outer edge of the first semi-circular pipe; there are two large annular grooves, two small annular grooves and gasket grooves in the inner circles of the first semi-circular pipe and the second semi-circular pipe respectively; there is a gasket groove on each side of each large annular groove; the two large annular grooves respectively wrap the large annular ribs at the ends of the bamboo joint-shaped prestressed plastic pipe; the two small annular grooves respectively wrap the small annular ribs at the ends of the bamboo joint-shaped prestressed plastic pipe; and gaskets are respectively installed in the gasket grooves.

[0004] The circular pipe joint mentioned in the above structure or the current standard JT / T 529-2016 "Plastic Corrugated Pipe for Prestressed Concrete Bridges" has the following deficiencies: First, there are many parts, including a semi-circular clamping segment with an exhaust hole (the clamping segment needs to be opened with a sealing ring groove, a clamping groove, and an exhaust hole, and needs to be manufactured by separate die-casting), a semi-circular clamping segment without an exhaust hole (the clamping segment needs to be opened with a sealing ring groove and a clamping groove, and needs to be manufactured by separate die-casting), a sealing ring (this sealing ring is a special-shaped sealing ring and needs to be manufactured by separate die-casting), and two locking wedge-shaped inserts (need to be manufactured by separate die-casting). The structure is complex and 4 die-castings are required; Second, the two-piece sealing method is adopted, which increases the risk of sealing failure, and high requirements are imposed on the cooperation of the two-piece sealing rings; Third, the locking wedge-shaped insert is relatively weak. When in use, the sealing ring is completely compressed by two relatively thin locking wedge-shaped inserts to make the two semi-circular clamping segments snap together. The force is concentrated at the folding angle, resulting in deformation or cracking at the folding angle and sealing failure; Fourth, the installation of the locking wedge-shaped insert is difficult. After installing the locking wedge-shaped insert on one side first, due to the pressing of the installed side, the other half will tilt, making it difficult to install the other side. The installation of the two locking wedge-shaped inserts needs to be carried out simultaneously; Fifth, when the overall structure is applied, the force is unreasonable. When performing a water pressure or air pressure tightness test inside the assembled pipeline, a circular external extrusion force is formed inside the pipeline, which is transmitted to the locking wedge-shaped insert through the two semi-circular clamping segments, resulting in an increase in the concentrated force and making it easy for the locking wedge-shaped insert to deform and the seal to fail; Sixth, the overall structure has poor flexibility. When the prestressed pipeline is designed, installed and applied, it is impossible to be a straight line and there is a certain angle of bending. The force received during bending is a lateral force, and the force received by this structure during buckling is a longitudinal force (that is, the two semi-circular clamping segments and the locking wedge-shaped insert are longitudinally rigidly connected), and it cannot adapt to the lateral load received in actual applications.

[0005] The flat pipe joint mentioned in the current standard JT / T 529-2016 "Plastic Corrugated Pipe for Prestressed Concrete Bridges" has different structural forms and connection principles from the circular pipe joint, and has the following deficiencies: First, there are also many parts, including a flat tee (needs to be manufactured by separate die-casting), a flat straight-through (needs to be manufactured by separate die-casting), and two flat clamps (needs to be manufactured by separate die-casting). The structure is complex and 4 die-castings are required; Second, both the water tightness and air tightness are unreliable. The connection is a direct surface contact between the flat clamp and the flat plastic pipe joint, flat tee, and flat straight-through respectively, without any sealing measures.

[0006] To sum up, in order to solve the connection between two sections of plastic corrugated pipes and give full play to the role of plastic corrugated pipes, it is necessary to make the connection between the two sections of corrugated pipes have good sealing performance and good flexibility. In terms of production and construction costs, the structure should be simple, easy to manufacture, and easy to install. Summary of the Invention

[0007] The present invention provides a plastic corrugated pipe joint for prestress and an installation method thereof. The structure and the installation method are simple. While being able to solve the problem of pipe sealing, the connection part has a certain flexibility, which can preferably reduce the influence of installation errors on construction, greatly improve the quality of the connection of plastic corrugated pipes for prestress, better conform to the application of actual working conditions, and provide a basic guarantee for the electrical monitoring of prestressed steel tendons in the pipe.

[0008] The technical solution of the present invention is as follows:

[0009] A plastic corrugated pipe joint for prestress, including a joint body. The two ends of the joint body are respectively connected to two plastic corrugated pipe sections to be pre-connected. It also includes a heat shrinkable sleeve and a sealing ring. The heat shrinkable sleeve is wrapped around the outer circumference of the joint body and extends to wrap the outer wall of the plastic corrugated pipe section. The inner wall of the joint body that cooperates with the plastic corrugated pipe section is arranged as a tapered structure with a gradually decreasing diameter from shallow to deep.

[0010] The top of the first wave crest of the plastic corrugated pipe section is in interference fit connection with the joint body, and the top of the second wave crest of the plastic corrugated pipe section is in clearance fit connection with the joint body. The first wave crest is defined as the deepest wave crest, and the second wave crest is defined as the second deepest wave crest.

[0011] An inner convex platform is arranged in the middle of the axial direction of the inner wall of the joint body. The inner convex platform and the side wall of the innermost wave crest of the plastic corrugated pipe section are sealed and abutted through a sealing ring.

[0012] The present invention adopts a combined seal of a heat shrinkable sleeve and a joint body, with double seals, and has good sealing performance.

[0013] The present invention adopts interference fit and clearance fit at two places of the joint body respectively, which not only ensures the sealing performance but also ensures the flexibility. There is a clearance fit or flexible connection at the connection part, and the whole system is circumferentially stressed, making the overall system have a certain impact resistance, flexibility, bending resistance and construction convenience, and making the sealing of the pipeline system more reliable during application, which is easy to promote and apply.

[0014] The present invention adopts an integral joint body. Compared with the original structure which requires 3 to 4 molds, only 1 mold is needed for this connector. The structure is also simple, the cost is low, and it is easy to promote and apply.

[0015] Preferably, the inner diameter of the sealing ring and the outer diameter of the wave trough of the plastic corrugated pipe section are in interference fit. When the sealing ring is sleeved on the wave trough of the plastic corrugated pipe section, the outer diameter is larger than the outer diameter of the wave crest of the plastic corrugated pipe section. The outer diameter of the sealing ring and the inside of the joint body 3 are in interference fit. The inner wall and the outer wall of the sealing ring both adopt interference fit to ensure the sealing performance.

[0016] Preferably, the sealing ring is one of an O-shaped rubber or silicone rubber sealing ring. It has a simple structure, is easy to install, and has a low cost.

[0017] Preferably, the number of wave crests of the plastic corrugated pipe section sleeved on any one side of the joint body is more than 2, which can better ensure the sealing performance.

[0018] Preferably, the inner wall of the heat-shrinkable sleeve is coated with hot-melt adhesive. The inner wall of the heat-shrinkable sleeve contains hot-melt adhesive and tightly fits with the plastic corrugated pipe section and the joint body after installation. It can not only enhance the ability of the entire connection system to resist longitudinal and lateral forces, but also play a role of double sealing. The wrapping range of the heat-shrinkable sleeve after installation needs to be larger than the wave crest of at least one plastic corrugated pipe section outside any one side of the joint body, further improving the sealing performance of the connection.

[0019] Preferably, the inner convex platform structure is an integral annular structure arranged on the inner wall of the joint body. It has a simple structure, is easy to process, and has a low cost.

[0020] Preferably, the joint body is made of plastic, which has a low cost, good flexibility, and is easy to install.

[0021] Preferably, the inner convex platform structure is an axially arranged inner convex rib platform arranged on the inner wall of the joint body. The number of the inner convex rib platforms is more than 3, and the inner convex rib platforms are evenly arranged on the circumferential surface. Adopting the form of ribs, the structure is simplified, the volume of the inner convex platform is smaller, and it is convenient for lightweight design.

[0022] In addition, the present invention also provides an installation method for a plastic corrugated pipe joint for prestress, including the following steps:

[0023] Step 1: First, put the sealing ring on the wave trough position at one end of the pre-connected plastic corrugated pipe section on one side.

[0024] Step 2: Insert the plastic corrugated pipe section with the sealing ring into the joint body as a whole, and ensure that the sealing ring is inserted into the position of the inner convex platform of the joint body until the inner convex platform abuts against the sealing ring.

[0025] Step 3: Put the sealing ring on the wave trough at one end of the plastic corrugated pipe section on the other side, and then insert it into the joint body as a whole, and ensure that the sealing ring is inserted into the position of the inner convex platform of the joint body until the inner convex platform abuts against the sealing ring.

[0026] Step 4: Put the heat-shrinkable sleeve on the outer wall of the joint body and the outer walls of the two pre-connected plastic corrugated pipe sections, and use tools to shrink the heat-shrinkable sleeve, and at the same time wrap the joint body and the plastic corrugated pipe section into a whole.

[0027] The method described in the present invention utilizes the characteristics of the corrugated pipe having wave crests and wave troughs. At the connection, a sealing sleeve or sealing ring is sleeved on the wave crest or wave trough at both ends of the corrugated pipe, and a circumferential seal is formed in cooperation with the connecting head. Moreover, the sealing sleeve, sealing ring, and heat-shrinkable sleeve can all be standard parts available on the market, so that two circular plastic corrugated pipe joints can be connected and sealed.

[0028] The same principle can be adopted to simultaneously adapt to circular plastic pipe joints and flat plastic pipe joints, and this structure and method have great application value.

[0029] Preferably, in step four, the wrapping range of the heat-shrinkable sleeve needs to be greater than the wave crest of at least one plastic corrugated pipe joint on either side of the joint body. Interference sealing fit is adopted with the wave crest to further ensure the sealing performance of the connection.

[0030] The beneficial effects of the present invention are as follows:

[0031] 1. This circular exhaust-hole-free connecting head for prestressed plastic corrugated pipes has good sealing performance, a simple structure, and low cost through the combined sealing of the heat-shrinkable sleeve and the joint body, adopting double sealing.

[0032] 2. Compared with the original structure that requires 3 to 4 molds, this connecting head only needs to open 1 mold for the circular exhaust-hole-free joint.

[0033] 3. The installation method described in the present invention utilizes the characteristics of the corrugated pipe having wave crests and wave troughs. At the connection, a sealing sleeve or sealing ring is sleeved on the wave crest or wave trough at both ends of the corrugated pipe, and a circumferential seal is formed in cooperation with the connecting head. Moreover, the sealing sleeve, sealing ring, and heat-shrinkable sleeve can all be standard parts available on the market, so that two circular plastic corrugated pipe joints can be connected and sealed.

[0034] 4. There is an interference fit or flexible connection at the connection of the present invention, and the whole system is circumferentially stressed, making the overall system have certain impact resistance, flexibility, bending resistance, and construction convenience, so that the sealing performance of the pipeline system is more reliable during application and is easy to promote and apply.

[0035] 5. The structure of the present invention can adopt the same principle to simultaneously adapt to circular plastic pipe joints and flat plastic pipe joints. This structure and method have great application value and are easy to promote and apply. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 is a schematic structural diagram of a plastic corrugated pipe joint for prestressed use according to the present invention.

[0037] Figure 2 is a cross-sectional structural schematic diagram of the joint body according to the present invention.

[0038] Figure 3It is a schematic structural diagram of the sealing ring of the present invention installed on the plastic corrugated pipe joint.

[0039] Figure 4 It is a schematic structural diagram of the sealing ring of the present invention.

[0040] Figure 5 It is a three-dimensional structural schematic diagram of the joint body of Embodiment 3 of the present invention.

[0041] Figure 6 It is a schematic structural diagram of the sealing sleeve of Embodiment 5 of the present invention.

[0042] Figure 7 It is a structural diagram of the sealing sleeve of Embodiment 5 of the present invention installed on the plastic corrugated pipe joint.

[0043] Figure 8 It is a schematic overall structural diagram of Embodiment 5 of the present invention.

[0044] Figure 9 It is a schematic overall structural diagram of Embodiment 6 of the present invention.

[0045] Figure 10 It is a schematic structural diagram of the plastic corrugated pipe joint in Embodiment 7 of the present invention.

[0046] Figure 11 It is a schematic structural diagram of the joint body in Embodiment 7 of the present invention.

[0047] Figure 12 It is a three-dimensional structural schematic diagram of the joint body in Embodiment 2 of the present invention.

[0048] In the figure: 1 - plastic corrugated pipe joint, 11 - first wave crest, 12 - second wave crest, 2 - heat shrinkable sleeve, 3 - joint body, 31 - inner convex platform, 32 - exhaust hole, 4 - sealing ring, 5 - sealing sleeve. Detailed implementation manners

[0049] The present invention will be further described below in conjunction with the accompanying drawings and detailed implementation manners. The illustrative embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation to the present invention.

[0050] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by the terms "left", "right", "upper", "lower", "front", "rear", etc. is based on the orientation or positional relationship shown in the accompanying drawings, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or structure referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to the present invention.

[0051] Embodiment 1:

[0052] AsFigure 1 and Figure 2 As shown in Figure 2 , a plastic corrugated pipe joint for prestress includes a joint body 3. The two ends of the joint body 3 are respectively connected to two plastic corrugated pipe sections 1 to be pre-connected. It also includes a heat-shrinkable sleeve 2 and a sealing ring 4. The heat-shrinkable sleeve 2 is coated on the outer circumference of the joint body 3 and extends to cover the outer wall of the plastic corrugated pipe section 1. The inner wall of the joint body 3 that cooperates with the plastic corrugated pipe section 1 is set as a conical structure with a gradually decreasing diameter from shallow to deep. The top of the first wave crest 11 of the plastic corrugated pipe section 1 and the joint body 3 are connected with an interference fit. The top of the second wave crest 12 of the plastic corrugated pipe section 1 and the joint body 3 are connected with a clearance fit. An inner boss 31 is arranged in the axial middle of the inner wall of the joint body 3. The inner boss 31 and the side wall of the innermost wave crest of the plastic corrugated pipe section 1 are sealed and abutted through the sealing ring 4.

[0053] Example 2:

[0054] As Figure 1 and Figure 2 shown in Figure 2 , a plastic corrugated pipe joint for prestress includes a joint body 3. The two ends of the joint body 3 are respectively connected to two plastic corrugated pipe sections 1 to be pre-connected.

[0055] In this embodiment, the plastic corrugated pipe section 1 is a circular plastic corrugated pipe section 1, and the joint body 3 is constructed as a circular joint without exhaust holes.

[0056] This embodiment also includes a heat-shrinkable sleeve 2 and a sealing ring 4. The heat-shrinkable sleeve 2 is coated on the outer circumference of the joint body 3 and extends to cover the outer wall of the plastic corrugated pipe section 1. The inner wall of the joint body 3 that cooperates with the plastic corrugated pipe section 1 is set as a conical structure with a gradually decreasing diameter from shallow to deep;

[0057] As Figure 2 and Figure 3 shown in Figure 3 , the top of the first wave crest 11 of the plastic corrugated pipe section 1 and the joint body 3 are connected with an interference fit, that is, φA > φF, to facilitate the insertion of the plastic corrugated pipe section 1 into the joint body 3; the top of the second wave crest 12 of the plastic corrugated pipe section 1 and the joint body 3 are connected with a clearance fit, that is, φB < φF, to facilitate clamping the plastic corrugated pipe section 1. The first wave crest 11 is defined as the deepest wave crest, and the second wave crest is defined as the second deepest wave crest;

[0058] An inner boss 31 is arranged in the axial middle of the inner wall of the joint body 3. The inner boss 31 and the side wall of the innermost wave crest of the plastic corrugated pipe section 1 are sealed and abutted through the sealing ring 4.

[0059] In this embodiment, through the combined seal of the heat-shrinkable sleeve 2 and the joint body 3, double sealing is adopted, and the sealing performance is good.

[0060] In this embodiment, interference fit and clearance fit are respectively adopted at two places of the joint body 3, which not only ensures the sealing performance but also ensures flexibility. There is a clearance fit or a flexible connection at the joint, and the whole system is circumferentially stressed, making the overall system have certain impact resistance, flexibility, bending resistance and construction convenience, and making the sealing performance of the pipeline system more reliable during application, which is easy to promote and apply.

[0061] This embodiment adopts an integral joint body 3. Compared with the original structure which requires 3 - 4 molds, only 1 mold is needed for this connector. The structure is also simple, the cost is low, and it is easy to promote and apply.

[0062] As Figures 2 to 4 shown, in this embodiment, the inner diameter of the sealing ring 4 and the outer diameter of the wave valley of the plastic corrugated pipe section 1 are in interference fit, that is, φG > φD, so as to facilitate the sealing ring 4 to be tightly sleeved on the wave valley of the outer diameter of the plastic corrugated pipe section 1; when the sealing ring 4 is sleeved on the wave valley of the plastic corrugated pipe section 1, its outer diameter is larger than the outer diameter of the wave peak of the plastic corrugated pipe section 1, that is, the outer diameter of the sealing ring 4 and the small diameter of the inner cone of the joint body 3 are in interference fit, φL > φF and φB < φF, and the outer diameter of the sealing ring 4 and the inside of the joint body 3 are in interference fit. Both the inner wall and the outer wall adopt interference fit to ensure the sealing performance.

[0063] As Figure 2 and Figure 3 shown, the inner diameter of the inner convex platform 31 is smaller than the wave peak of the outer diameter of the plastic corrugated pipe section and larger than the wave valley of the outer diameter of the plastic corrugated pipe section 1, that is, φD < φC < φF, which is used for positioning the insertion of the plastic corrugated pipe section 1 and is beneficial to the positioning of the sealing ring 4.

[0064] In this embodiment, the sealing ring 4 is an O - shaped rubber, which has a simple structure, is easy to install and has a low cost.

[0065] In this embodiment, the number of wave peaks of the plastic corrugated pipe section 1 sleeved on either side of the joint body 3 is more than 2, which better ensures the sealing performance.

[0066] In this embodiment, the inner wall of the heat - shrinkable sleeve 2 is coated with hot - melt adhesive, and the wrapping range after the installation of the heat - shrinkable sleeve 2 needs to be larger than at least one wave peak of the plastic corrugated pipe section 1 outside either side of the joint body 3, further improving the sealing performance of the connection.

[0067] As Figure 12 shown, in this embodiment, the inner convex platform 31 is configured as an integral annular structure provided on the inner wall of the joint body 3, which has a simple structure, is easy to process and has a low cost.

[0068] In this embodiment, the joint body 3 is made of plastic products, which have a low cost, good flexibility and are easy to install.

[0069] Example 3:

[0070] The difference between this example and the above Example 2 is that the sealing ring 4 is a silica gel sealing ring.

[0071] As Figure 5 shown, the inner convex platform 31 is configured as an axially arranged inner convex rib platform provided on the inner wall of the joint body 3. The number of the inner convex rib platforms is more than 3, and the inner convex rib platforms are evenly arranged on the circumferential surface.

[0072] Example 4:

[0073] This example is the installation method of the above Example 2, including the following steps:

[0074] Step 1: First, put the sealing ring 4 on the trough position at one end of the pre-connected plastic corrugated pipe joint 1 on one side;

[0075] Step 2: Insert the plastic corrugated pipe joint 1 with the sealing ring 4 into the joint body 3 as a whole, and ensure that the sealing ring 4 is inserted to the shoulder position of the inner convex platform 31 of the joint body 3 until the shoulder of the inner convex platform 31 abuts against the sealing ring 4;

[0076] Step 3: Put the sealing ring 4 on the trough at one end of the plastic corrugated pipe joint 1 on the other side, and then insert it into the joint body 3 as a whole, and ensure that the sealing ring 4 is inserted to the position of the inner convex platform 31 of the joint body 3 until the inner convex platform 31 abuts against the sealing ring 4;

[0077] Step 4: Slip the heat shrinkable sleeve 2 onto the outer wall of the joint body 3 and the outer walls of the two pre-connected plastic corrugated pipe joints 1, and use tools to shrink the heat shrinkable sleeve 2, and at the same time wrap the joint body 3 and the plastic corrugated pipe joints 1 into a whole.

[0078] Further, in Step 4 of this example, in Step 4, the wrapping range of the heat shrinkable sleeve 2 needs to be greater than the wave crest of at least one plastic corrugated pipe joint 1 outside any single side of the joint body 3, and interference sealing fit is adopted with the wave crest to further ensure the sealing performance of the connection.

[0079] Example 5:

[0080] As Figure 6 and Figure 7 shown, the difference between this example and Example 2 is that the sealing ring 4 is replaced by a sealing sleeve 5. The sealing ring 4 in Example 2 is sleeved on the trough position of the plastic corrugated pipe joint 1, while the sealing sleeve 5 in Example 5 is sleeved on the wave crest position of the plastic corrugated pipe joint 1.

[0081] As Figure 7 and Figure 8As shown, the sealing sleeve 5 is further characterized in that its material is rubber or silica gel. The inner diameter of the sealing sleeve 5 and the trough of the outer diameter of the plastic corrugated pipe section 1 are in interference fit, that is, φK < φD. When the sealing sleeve 5 is sleeved on the peak of the outer diameter of the plastic corrugated pipe section 1, its outer diameter φM is greater than the peak φF of the outer diameter of the plastic corrugated pipe section 1, that is, when the sealing sleeve 5 is sleeved on the peak of the outer diameter of the plastic corrugated pipe section 1, the outer diameter φM and the minor diameter φB of the inner cone of the joint body 3 are in interference fit, φM > φF and φB < φM.

[0082] The installation method of this embodiment is as follows

[0083] Step 1: First, put the sealing sleeve 5 on the peak position at one end of a plastic corrugated pipe section 1;

[0084] Step 2: Insert the plastic corrugated pipe section 1 with the sealing sleeve 5 sleeved on it as a whole into the joint body 3 until the inner boss 31 of the joint body 3 abuts against the sealing sleeve 5.

[0085] Step 3: At the other end, put the sealing sleeve 5 on the peak position at one end of another plastic corrugated pipe section 1, and then insert it as a whole into the joint body 3 until the inner boss 31 of the joint body 3 abuts against the sealing sleeve 5.

[0086] Step 4: Slip the heat shrinkable sleeve 2 onto the joint body 3, and use a tool to shrink the heat shrinkable sleeve 2, while wrapping the joint body 3 and the plastic corrugated pipe section 1 into a whole. The wrapping range of the heat shrinkable sleeve 2 needs to be greater than at least one peak of the plastic corrugated pipe section 1 outside the single side of the joint body 3.

[0087] After installation, the structure is as Figure 8 shown.

[0088] Embodiment 6:

[0089] The difference between this embodiment and the above-mentioned Embodiment 2 is that:

[0090] Because when prestressed duct grouting is required, there need to be vent holes and grouting holes, so vent holes need to be opened between the pipes for use as vent holes or grouting holes during prestressed duct grouting. As Figure 9 shown, in Embodiment 6, a vent hole (32) is opened in the middle of the joint body 3 mentioned in Embodiment 2, that is, the joint body 3 is constructed as a circular joint structure with a vent hole.

[0091] Steps 1 to 3 of Embodiment 6 are the same as those of Embodiment 4.

[0092] Step four of Embodiment 6 is as follows: Slip heat shrinkable sleeves 2 onto both ends of the circular connector with exhaust holes until reaching the interface position between the circular connector with exhaust holes and the plastic corrugated pipe section 1. Use tools to shrink the heat shrinkable sleeves 2, and at the same time wrap the circular connector with exhaust holes and the plastic corrugated pipe section 1 into a whole. The wrapping range of the heat shrinkable sleeves 2 should be greater than the crest of at least one plastic corrugated pipe section 1 outside the single side of the circular connector with exhaust holes.

[0093] Embodiment 7:

[0094] As Figure 10 shown, the difference between this embodiment and the above Embodiment 6 is that the plastic corrugated pipe section 1 of this embodiment is constructed as a flat plastic corrugated pipe section. Its principle is the same as that of connecting the circular plastic corrugated pipe section 1. The difference is that according to the shape characteristics of the flat plastic corrugated pipe section, the joint body 3 is set as a suitable flat connector without exhaust holes and a flat connector with exhaust holes.

[0095] The application steps of the joint body 3 in this embodiment are the same as those in Embodiment 6. As Figure 11 shown, the flat connector with exhaust holes in this embodiment is the same as that in Embodiment 6.

[0096] The above embodiments of the plastic corrugated pipe connector for prestress and its installation method are only for the preferred solutions and installation method descriptions of the present invention, and are not limitations on the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements on some of the technical features. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included within the protection scope of the present invention.

Claims

1. A plastic corrugated pipe joint for prestress, comprising a joint body (3), wherein two ends of the joint body (3) are respectively connected to two pre-connected plastic corrugated pipe sections (1), and the characteristics are as follows: It also comprises a heat shrink sleeve (2) and a sealing ring (4), wherein the heat shrink sleeve (2) is covered on the outer circumference of the joint body (3) and the two ends extend to cover the outer wall of the plastic bellows pipe section (1) on both sides of the joint body (3); the inner wall of the joint body (3) and the plastic bellows pipe section (1) are arranged to be a conical structure with a diameter gradually decreasing from shallow to deep; the top of the first wave crest (11) of the plastic bellows pipe section (1) and the joint body (3) are connected by interference fit; the top of the second wave crest (12) of the plastic bellows pipe section (1) and the joint body (3) are connected by clearance fit; an inner boss (31) is arranged in the axial middle part of the inner wall of the joint body (3); the inner boss (31) and the side wall of the first wave crest (11) of the plastic bellows pipe section (1) are sealed and abutted by the sealing ring (4); the first wave crest (11) is defined as the deepest wave crest, and the second wave crest (12) is defined as the second deepest wave crest.

2. The plastic corrugated pipe joint for prestress according to claim 1, characterized in that: The inner diameter of the sealing ring (4) and the outer diameter of the trough of the plastic bellows pipe section (1) are in interference fit; the outer diameter of the sealing ring (4) when sleeved on the trough of the plastic bellows pipe section (1) is larger than the outer diameter of the crest of the plastic bellows pipe section (1); and the outer diameter of the sealing ring (4) and the interior of the joint body (3) are in interference fit.

3. A plastic corrugated pipe joint for prestress according to claim 1 or 2, characterized in that: The sealing ring (4) is an O-type rubber or silicone sealing ring.

4. A plastic corrugated pipe joint for prestress according to claim 1 or 2, characterized in that: The number of wave crests that can be unilaterally sheathed on any one side of the joint body (3) and the plastic corrugated pipe section (1) is more than two.

5. A plastic corrugated pipe joint for prestress according to claim 1 or 2, characterized in that: The inner wall of the heat shrinkable tube (2) is coated with hot melt adhesive, and the wrapping range of the heat shrinkable tube (2) after installation needs to be larger than the wave crest of at least one plastic corrugated tube section (1) outside one side of any one side of the joint body (3).

6. A plastic corrugated pipe joint for prestressing according to claim 1 or 2, characterized in that: The inner boss (31) is configured as a full-ring structure arranged on the inner wall of the joint body (3).

7. A plastic corrugated pipe joint for prestress according to claim 1 or 2, characterized in that: The joint body (3) is made of plastic.

8. A plastic corrugated pipe joint for prestress according to claim 1 or 2, characterized in that: The inner boss (31) is constructed as an axially arranged inner convex rib boss arranged on the inner wall of the joint body (3), and the number of the inner convex rib bosses is more than 3.

9. An installation method of a plastic corrugated pipe joint for prestress as described in any one of the above claims, characterized in that The steps include: Step 1: First, put a sealing ring (4) on the trough position of one end of the pre-connected plastic corrugated pipe section (1); Step 2: Insert the plastic corrugated pipe section (1) with the sealing ring (4) into the joint body (3) as a whole, and ensure that the sealing ring (4) is inserted to the position of the inner boss (31) of the joint body (3) so that the inner boss (31) presses against the sealing ring (4); Step 3: Put a sealing ring (4) on the trough of one end of the plastic corrugated pipe section (1) on the other side, and then insert the whole into the joint body (3), ensuring that the sealing ring (4) is inserted to the position of the inner boss (31) of the joint body (3) so that the inner boss (31) presses against the sealing ring (4); Step 4: Insert the heat shrink tube (2) onto the outer wall of the connector body (3) and the outer wall of the two pre-connected plastic bellows pipe sections (1), shrink the heat shrink tube (2) with a tool, and wrap the connector body (3) and the plastic bellows pipe sections (1) into a whole.

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