Polyether-ether-ketone pipeline induction welding structure
By embedding a metal ring inside the PEEK composite pipe joint and using induction heating welding, the applicability and quality issues of PEEK composite pipe connections have been solved, achieving high-strength and stable pipe connections, and improving production efficiency and adaptability.
Patent Information
- Application Number
- CN202520466301.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-03-17
- Publication Date
- 2026-03-17
- Estimated Expiration
- 2035-03-17
AI Technical Summary
In existing technologies, PEEK composite pipe joints have problems such as limited applicability, unstable connection quality, easy damage to pipe surfaces, and uneven heat distribution, especially in large-diameter pipes and flexible clamp connection systems.
The PEEK pipe induction welding structure is adopted. By nesting a metal ring inside the joint and using induction heating, PEEK resin is penetrated into the circular hole of the metal ring, achieving a high-strength connection between the pipe and the joint. Combined with injection molding, stability and adaptability are ensured.
It achieves high-strength and stable pipe connections, is suitable for joints of any size, reduces steps and time, improves production efficiency, and enhances adaptability to pipe structures and sizes.
Smart Images
Figure CN223999015U_ABST
Abstract
Description
Technical Field
[0001] This utility model belongs to the field of pipeline connection technology, specifically relating to a polyetheretherketone (PEEK) pipeline induction welding structure. Background Technology
[0002] With the increasing demand for lightweight piping in aircraft, PEEK (polyetheretherketone) composite piping, as a high-performance composite material, is gradually being used in water / wastewater, anti-icing / de-icing, and liquid cooling systems in the aviation industry. The connection of PEEK composite piping joints is a key factor limiting its application. Currently, small-diameter pipes mainly use flared threaded connections, while large-diameter pipes in low-pressure and negative-pressure conditions use secondary injection-molded joints. As a thermoplastic engineering plastic, PEEK can be melted and re-solidified multiple times. Induction welding uses electromagnetic induction to precisely heat the welding area, effectively avoiding mechanical damage to the pipe surface and improving welding efficiency and quality stability, making it one of the most promising welding technologies.
[0003] The disadvantages of existing PEEK composite pipe joints are summarized as follows:
[0004] 1. Flared threaded connections are only suitable for small-diameter pipes. There are no suitable nuts for connecting large-diameter pipes, which limits their application.
[0005] 2. The form of secondary injection molding joints has requirements on the external dimensions of the pipeline, and there are situations where the pressure resistance is low and the joint size accuracy cannot be guaranteed. It cannot be used for liquid cooling systems with flexible clamps and quick-release clamps.
[0006] 3. Connecting pipelines using traditional contact welding methods can easily damage the pipeline surface and result in uneven heat distribution, affecting the welding quality. Utility Model Content
[0007] To solve the technical problem of difficult connection of PEEK composite pipe joints, this utility model provides a polyetheretherketone pipe induction welding structure.
[0008] The objective of this utility model is achieved through the following technical solution. A polyetheretherketone (PEEK) pipeline induction welding structure is proposed according to this utility model, comprising a joint, the joint including a welding end for connecting to a pipe, the welding end of the joint having a welding cavity for accommodating the pipe inside, the outer wall of the pipe welding end contacting the inner wall of the welding cavity; a metal ring is nested in the inner wall of the welding cavity, and multiple groups of circular holes are distributed axially along the sidewall of the metal ring, each group of circular holes including multiple circumferentially distributed circular holes, the circular holes of adjacent groups of circular holes being staggered axially.
[0009] Furthermore, the inner wall of the metal ring is flush with the inner wall of the welding cavity.
[0010] Furthermore, one end face of the metal ring is flush with the welding end face of the joint.
[0011] Furthermore, the inner wall of the joint is provided with a stop step, and after the tube is inserted into the joint, it rests against the stop step so that the welded end of the tube is located inside the metal ring.
[0012] Furthermore, the other end of the connector is a connection end for connecting to a device or pipeline, and the inside of the connection end is a connection cavity that communicates with the welding cavity.
[0013] Furthermore, the connector is made of polyetheretherketone (PEEK) material, and the tube is made of PEEK material.
[0014] Furthermore, the circular holes are evenly distributed on the metal ring.
[0015] Furthermore, the metal ring is fixed to the inner wall of the joint by injection molding.
[0016] Furthermore, when heating the metal ring welding joint and the pipe, counterweights are placed inside the joint and the non-welded end of the pipe.
[0017] Furthermore, when heating the metal ring welding joint and the pipe, an outer retaining ring is fitted on the outer wall of the welding end of the joint, and an inner expansion sleeve is nested in the inner hole of the welding end of the pipe.
[0018] Compared with the prior art, the advantages of this utility model are:
[0019] The connector and pipe are welded with an embedded metal ring, allowing PEEK resin to fully penetrate the mesh-like metal ring, effectively anchoring the pipe and connector for a high-strength connection. The connector can be injection molded, suitable for any connector type. The inner wall of the connector is embedded with a mesh-like metal ring and injection molded. The connector and pipe are welded using induction heating, resulting in a stronger bond and higher pressure resistance compared to secondary injection molding. Compared to secondary injection molding, this invention reduces steps, shortens time, improves production efficiency, and offers greater adaptability to pipe structures and dimensions.
[0020] The above description is only an overview of the technical solution of this utility model. In order to better understand the technical means of this utility model and to implement it in accordance with the contents of the specification, and to make the purpose, features and advantages of this utility model more obvious and easy to understand, the following are preferred embodiments, and detailed descriptions are provided in conjunction with the accompanying drawings. Attached Figure Description
[0021] Figure 1 This is a sectional perspective view of the joint in an embodiment of the induction welding structure for polyetheretherketone (PEEK) pipelines according to this utility model.
[0022] Figure 2This is a half-sectional view of the joint in an embodiment of the induction welding structure for polyetheretherketone (PEEK) pipelines of this utility model;
[0023] Figure 3 for Figure 1 , Figure 2 A three-dimensional schematic diagram of the central metal ring;
[0024] Figure 4 for Figure 3 Side view;
[0025] Figure 5 for Figure 1 , Figure 2 Schematic diagram of the connection between the connector and the pipe;
[0026] Figure 6 This is a schematic diagram of an embodiment of the induction welding structure for polyether ether ketone (PEEK) pipes, in which both ends of the pipe are connected to joints.
[0027] Figure label:
[0028] 1-Metal ring,
[0029] 101-Round hole,
[0030] 2-Connector,
[0031] 201-Stop Step,
[0032] 202-Welding cavity,
[0033] 203-Connecting cavity,
[0034] 3-tube. Detailed Implementation
[0035] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. The components of the embodiments of this application described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.
[0036] Therefore, the following detailed description of the embodiments of this application provided in the accompanying drawings is not intended to limit the scope of the claimed application, but merely to illustrate selected embodiments of the application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.
[0037] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.
[0038] In the description of this application, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product of this application is in use. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on this application. In addition, the terms "first," "second," and "third," etc., are only used to distinguish descriptions and should not be construed as indicating or implying relative importance.
[0039] Furthermore, terms such as "horizontal," "vertical," and "sag" do not imply that components must be absolutely horizontal or suspended, but rather that they can be slightly tilted. For example, "horizontal" simply means that its direction is more horizontal relative to "vertical," and does not mean that the structure must be completely horizontal, but can be slightly tilted.
[0040] In the description of this application, it should also be noted that, unless otherwise expressly specified and limited, the terms "set up," "install," "connect," and "link" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.
[0041] In this application, unless otherwise expressly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature being directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature being directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.
[0042] The following detailed description, in conjunction with embodiments, further illustrates the features and performance of the present application's induction welding structure suitable for polyether ether ketone (PEEK) pipelines.
[0043] An embodiment of the induction welding structure for polyetheretherketone (PEEK) pipelines according to this utility model is as follows: Figures 1 to 6As shown. The induction welding structure includes a joint 2 and a pipe 3. Both joint 2 and pipe 3 are made of PEEK (polyether ether ketone), but can also be made of other composite materials that melt after heating and solidify after cooling.
[0044] The inner wall of connector 2 is embedded with a mesh-like metal ring 1. The metal ring 1 is cylindrical, and its sidewalls are provided with staggered circular holes 101. Specifically, multiple groups of circular holes are axially distributed on the sidewalls of the metal ring 1. Each group of circular holes has multiple holes 101 distributed upwards on the circumferential direction of the metal ring 1, and the holes 101 in adjacent groups of circular holes are staggered axially. When the tube 3 is inserted into connector 2, the metal ring 1 is also inserted. The metal ring 1 is heated by induction heating, melting the PEEK material at the welding ends of the tube 3 and connector 2. The molten PEEK material flows into the circular holes 101. Since the circular holes 101 are staggered axially, the PEEK material flowing into the circular holes 101 is also staggered. The gaps between the inner wall of connector 2, the inner wall of metal ring 1, and the outer wall of tube 3 are filled with the axially staggered PEEK material. The liquid in the pipe flows axially, which can enhance the sealing effect. Therefore, the staggered circular holes 101 along the axial direction allow for a better sealing effect after the connector 2 is welded to the corresponding pipe 3. After the pipe 3 is inserted into the connector 2 and welded in place, the axial connection between the pipe 3 and the connector 2 is relatively weak. By impregnating the staggered circular holes 101 along the axial direction with PEEK resin, the axial tensile strength can be increased, ensuring a firm connection between the pipe 3 and the connector 2.
[0045] The circular holes 101 on the metal ring 1 are evenly distributed. After the PEEK resin is fully melted, it is evenly distributed into each of the circular holes 101, which can effectively disperse stress, reduce local stress concentration, and make the bonding strength higher. When the tube 3 is inserted into the connector 2, the tube 3 is also inserted into the metal ring 1. The metal ring 1 is heated by induction welding. The metal ring 1 heats up and melts the connector 2 and the tube 3. The melted connector 2 and the tube 3 are embedded in the circular holes 101 and solidify. The connector 2 and the tube 3 achieve an anchoring effect with the metal ring 1, thereby realizing the effective connection between the connector 2 and the tube 3.
[0046] One end of connector 2 is a welding end for welding to pipe 3, and the other end is a connecting end for connecting to other pipes or devices. The welding end of connector 2 has a welding cavity 202, and the connecting end has a connecting cavity 203, which are connected. A stop step 201 is provided on the inner wall of connector 2 to separate the welding cavity 202 and the connecting cavity 203. The inner diameter of the welding cavity 202 is larger than the inner diameter of the connecting cavity 203. A metal ring 1 is nested within the inner wall of the welding cavity 203, and the inner wall of the metal ring 1 is flush with the inner wall of the welding cavity 203. Pipe 3 is inserted into the welding cavity 202 and pressed against the stop step 201 to position it. At this point, the inserted end of pipe 3 is positioned within the metal ring 1. During induction welding, the heat generated by the metal ring 1 melts the inserted end of pipe 3 and the inner wall of the welding cavity 202, thus firmly bonding pipe 3 and connector 2 through the metal ring 1.
[0047] The fixing method of connector 2 and metal ring 1 is as follows: connector 2 is formed by injection molding, and metal ring 1 is pre-fixed into the molding mold of connector 2 as an insert. The fixing position corresponds to the welding end position of connector 2. The thermoplastic injection machine is adjusted and the optimal process parameters are set. After injection molding, the outer end face of metal ring 1 is flush with the welding end face of connector 2 blank. The interface dimension accuracy of connector 2 is ensured by supplementary machining. After machining, the outer end face of metal ring 1 is flush with the welding end face of connector 2.
[0048] After connector 2 is injection molded and fixed to metal ring 1, tube 3 is inserted into connector 2 and positioned by stop step 201. The outer wall of tube 3 contacts the inner wall of metal ring 1. Metal ring 1 is heated by electromagnetic induction, causing the PEEK resin in contact with metal ring 1 to melt and fully impregnate the circular hole 101 of metal ring 1. Tube 3 is coaxially connected to connector 2, with the outer diameter of tube 3 being the same as the inner diameter of connector 2, allowing tube 3 to be inserted into connector 2. After insertion, tube 3 forms surface contact, ensuring full contact with metal ring 1. Before welding, counterweights are placed on connector 2 and tube 3 respectively. The counterweights can be placed inside the non-welded ends of connector 2 and tube 3 to prevent axial displacement of connector 2 and tube 3 during heating and welding, thus maintaining their positions. Before welding, an outer retaining ring is fitted onto the outer wall of joint 2 (the overlapping section of pipe 3 and joint 2) at the welding position. An inner expansion sleeve is nested inside the inner hole of pipe 3 (the overlapping section of pipe 3 and joint 2) at the welding position. Pressure is applied from the outside in through the outer retaining ring to the outer circumference of the welding position, and pressure is applied from the inside out through the inner expansion sleeve to the inner circumference of the welding position. This tightens the inner hole wall, maintaining the circumferential shape at the welding position during welding and compacting the molten PEEK resin material, filling the gap between joint 2 and pipe 3, enhancing the welding effect, and increasing the connection strength between pipe 3 and joint 2. During welding, parameters such as welding pressure (applied through the inner expansion sleeve and outer retaining ring), welding current, and welding time are strictly controlled. Auxiliary tools such as the inner expansion sleeve, outer retaining ring, and counterweights are used to achieve a high-strength connection between joint 2 and pipe 3. In this embodiment, the outer retaining ring can be a clamp tightened by bolts. The clamp is clamped at the welding position. During welding, the bolts are gradually tightened so that the clamp applies pressure to the joint 2. The inner expansion sleeve can be an expansion sleeve. Before welding, the expansion sleeve is inserted into the pipe 3. During welding, the expansion sleeve is operated so that the expansion sleeve expands outward and presses against the inner wall of the pipe 3.
[0049] like Figure 5 The diagram shows the connection between connector 2 and pipe 3. Pipe 3 can be connected to corresponding pipes or components via connector 2. Alternatively, connector 2 can be welded to both ends of pipe 3, such as... Figure 6 As shown, the pipes or devices on both sides of the pipe 3 can be connected through the connectors 2 at both ends of the pipe 3.
[0050] Preferably, the inner diameter of the mesh metal ring 1 is 57 mm, the thickness is 1.4 mm, the width is 20 mm, and the diameter of the circular hole is 2 mm. The inner diameter of the welding end of the connector 2 is 57 mm, and the wall thickness is 1.5 mm. When the metal ring 1 and connector 2 are integrally injection molded, the nozzle temperature at the outlet of the thermoplastic injection molding machine is 405℃, the injection pressure is 150 bar, the injection speed is 80 mm / s, the holding pressure is 80 bar, the holding time is 8 s, the cooling time is 200 s, and the mold temperature is 195℃. The outer diameter of the tube 3 is 57 mm, and the wall thickness is 1.5 mm. When the tube 3 and connector 2 are induction welded, a knob-type adjustable electromagnetic heating device is used. The welding power is about 0.3 kW, the welding time is about 65 s, and the welding pressure is about 6 kg. The welding pressure can be achieved by the inner expansion sleeve, the outer retaining ring, and the counterweight.
[0051] The connector 2 with an embedded metal ring 1 is welded to the pipe 3. PEEK resin can fully penetrate the mesh-like metal ring 1, effectively anchoring the pipe 3 to the connector 2 and achieving a high-strength connection between them. The connector 2 can be injection molded, suitable for any connector type. The inner wall of the connector 2 is embedded with the mesh-like metal ring 1 and injection molded. The connector 2 and pipe 3 are welded by induction heating, resulting in a higher bonding strength and greater pressure resistance than secondary injection molding. Compared with secondary injection molding, this invention reduces steps, shortens time, improves production efficiency, and has greater adaptability to pipeline structures and dimensions.
[0052] In another embodiment of a polyetheretherketone (PEEK) pipe induction welding structure, based on the above embodiment, the metal ring 1 can be completely located within the wall of the connector 2. When the metal ring 1 is heated, the wall of the connector 2 and the wall of the insertion end of the pipe 3 melt and solidify into one piece.
[0053] In another embodiment of a polyetheretherketone (PEEK) pipeline induction welding structure, based on the above embodiment, the metal ring 1 can be disposed on the inner wall of the connector 2 near the interior, and the outer end face of the metal ring 1 does not need to be flush with the welding end face of the connector 2.
[0054] The connection process of an embodiment of the polyetheretherketone (PEEK) pipeline induction welding structure of this utility model is summarized as follows:
[0055] (1) The connector 2 and the metal ring 1 are formed by injection molding. After injection molding, the metal ring 1 is nested in the inner wall of the connector 2 to form a connector 2 with the metal ring 1. Specifically, the metal ring 1 is pre-fixed in the molding mold of the connector 2 as an insert. The fixed position of the metal ring 1 corresponds to the welding end position of the connector 2 and is located in the inner wall of the connector 2 after injection molding. The thermoplastic injection machine is adjusted and the optimal process parameters are set. After injection molding, the outer end face of the metal ring 1 is flush with the welding end face of the connector 2 blank.
[0056] (2) The joint 2 after injection molding is machined by supplementary machining to ensure that the interface size accuracy of the joint 2 meets the design requirements.
[0057] (3) After the joint 2 is machined, the pipe 3 is inserted into the welding cavity 202 of the joint 2 and positioned by the stop step 201. The outer wall of the welding end of the pipe 3 contacts the inner wall of the metal ring 1.
[0058] (4) Position the joint 2 and the pipe 3 in the axial direction to prevent axial displacement caused by external force. Set an annular device on the outer wall of the joint 2 and the inner wall of the pipe 3 at the welding position to apply pressure from the outside to the inside to the outer wall of the joint 2 at the welding position and pressure from the inside to the outside to the inner wall of the pipe 3 at the welding position. This can maintain the circumferential shape at the welding position during subsequent welding and compact the melted PEEK resin material to fill the gap between the joint 2 and the pipe 3, thereby enhancing the welding effect. Specifically, counterweights are used to press down on joint 2 and pipe 3 respectively, or joint 2 and pipe 3 are clamped by clamping tools. The counterweights can be placed inside the non-welded ends of joint 2 and pipe 3 respectively to prevent axial displacement of joint 2 and pipe 3 during the heating and welding process, and keep the positions of joint 2 and pipe 3 unchanged. An outer retaining ring is fitted on the outer wall of joint 2 (overlapping section of pipe 3 and joint 2) at the welding position, and an inner expansion sleeve is nested in the inner hole of pipe 3 (overlapping section of pipe 3 and joint 2) at the welding position. Thus, during welding, pressure is applied from the outside to the inside on the outer circumference of the welding position, and pressure is applied from the inside to the outside on the inner circumference of the welding position, thus tightening the inner hole wall.
[0059] (5) The metal ring 1 is heated by electromagnetic induction, causing the PEEK resin on the joint 2 and pipe 3 in contact with the metal ring 1 to melt and fully impregnate the circular hole 101 of the metal ring 1. After the PEEK resin solidifies, the joint 2 and pipe 3 are connected. During the welding process, the welding pressure (pressure applied by the inner expansion sleeve and the outer retaining ring), welding current, welding time and other parameters are strictly controlled. Auxiliary tools such as the inner expansion sleeve, the outer retaining ring and the counterweight are used to achieve a high-strength connection between the joint 2 and the pipe 3.
[0060] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the appended claims and their equivalents.
Claims
1. A polyether ether ketone pipe induction welding structure comprising a joint (2), characterized in that: The joint (2) comprises a welding end for connecting with the pipe (3), and the welding end of the joint (2) is internally provided with a welding cavity (202) for accommodating the pipe (3), and the outer wall of the welding end of the pipe (3) is in contact with the inner wall of the welding cavity (202); the inner wall of the welding cavity (202) is nested with the metal ring (1), and the side wall of the metal ring (1) is axially provided with a plurality of circular hole groups, each of which comprises a plurality of circular holes (101) distributed in a ring shape, and the circular holes (101) of adjacent circular hole groups are axially staggered.
2. A polyether ether ketone pipe induction welding structure according to claim 1, characterized by: The inner wall of the metal ring (1) is flush with the inner wall of the welding cavity (202).
3. A polyether ether ketone pipe induction welding structure according to claim 1, characterized by: One end surface of the metal ring (1) is flush with the end surface of the welding end of the joint (2).
4. The polyether ether ketone plumbing induction welded structure of claim 1, wherein: The inner wall of the joint (2) is provided with a stop step (201), and the pipe (3) is abutted against the stop step (201) after being inserted into the joint (2) so that the welding end of the pipe (3) is located in the metal ring (1).
5. The polyether ether ketone plumbing induction welded structure of claim 1, wherein: The other end of the joint (2) is a connecting end for connecting with a device or a pipeline, and the connecting end is internally provided with a connecting cavity (203) which is in communication with the welding cavity (202).
6. A polyether ether ketone pipe induction welding structure according to claim 1, characterized by: The joint (2) is made of polyether ether ketone material, and the pipe (3) is made of polyether ether ketone material.
7. The polyether ether ketone pipe induction welding structure according to claim 1, characterized by: The circular holes (101) are uniformly distributed on the metal ring (1).
8. The polyether ether ketone plumbing induction welded structure of claim 1, wherein: The metal ring (1) is fixed on the inner wall of the joint (2) by means of injection molding.
9. The polyether ether ketone plumbing induction welded structure of claim 1, wherein: When the metal ring (1) is heated to weld the joint (2) and the pipe (3), the inside of the non-welding end of the joint (2) and the pipe (3) is provided with a counterweight.
10. The polyether ether ketone plumbing induction welded structure of claim 1, wherein: When the metal ring (1) is heated to weld the joint (2) and the pipe (3), an outer hoop retaining ring is sleeved on the outer wall of the welding end of the joint (2), and an inner expansion sleeve is nested in the inner hole of the welding end of the pipe (3).