A flange double-expanding self-aligning forming device and method for a steel-plastic composite pipe

Abstract

The application discloses a kind of steel plastic composite pipe flanging flange double-expanding self-aligning forming device and method, the device includes mould cavity forming part, mould core forming part, lifting mechanism, feed mechanism, die holder and rack, mould cavity forming part is set on the rack in front of mould core forming part;Mould core forming part includes horizontally arranged double-expanding die and self-aligning forming die, feed mechanism includes primary feed mechanism and secondary feed mechanism, lifting mechanism includes mould core sliding plate and sliding slot, sliding slot is longitudinally arranged on die holder, mould core sliding plate is slidably installed in sliding slot, and is connected with die holder by lifting hydraulic cylinder, die holder is arranged on rack by primary feed mechanism, double-expanding die is connected with mould core sliding plate by secondary feed mechanism, self-aligning forming die is arranged on mould core sliding plate and located below double-expanding die.The application solves the problem of uneven inner wall of pipeline caused by traditional forming die processing steel plastic composite pipe flanging flange product, and is suitable for steel plastic composite pipeline processing technical field.

Description

Technical Field

[0001] This invention belongs to the field of steel-plastic composite pipe processing technology, specifically, it relates to a steel-plastic composite pipe flange double-flaring self-aligning forming device and method. Background Technology

[0002] Steel-plastic composite pipe is a type of plastic composite pipe product with a steel wire mesh skeleton, possessing high strength and corrosion resistance. The flange forming technology for steel-plastic composite pipe is an indispensable and commonly used technique in pipe connection technology. However, currently, domestically produced steel-plastic composite pipe flange products all suffer from uneven inner walls and the presence of steps, affecting both the product's wear resistance and aesthetics.

[0003] Through experimental summary and mechanism analysis, it was found that the unevenness and steps on the inner wall of the steel-plastic composite pipe flange are related to the difference between the pipe's inner diameter and the diameter of the forming die core. When the difference is less than 1mm, the inner wall of the pipe is smooth without steps. However, when a forming die core of the same size as the inner diameter of the composite pipe is used to prepare the product, the inner wall of the pipe will experience material scraping due to the small gap between the two, causing the forming die core to be unable to enter the pipe for forming, or resulting in too low a smoothness of the inner wall of the pipe, making the product unusable. Therefore, the inner diameter of the forming die core for existing steel-plastic composite pipe flange forming dies in China is smaller than the inner diameter of the steel-plastic composite pipe in order to produce flange products. However, this results in uneven inner walls and steps in the products processed by this forming die core. To solve the problem of unevenness and steps on the inner wall of the product, this invention proposes a double-flaring self-aligning forming device and method to solve this problem. Summary of the Invention

[0004] This invention discloses a double-flaring self-aligning forming device for steel-plastic composite pipe flanges, which solves the problems of uneven inner walls and steps caused by using traditional forming molds to process steel-plastic composite pipe flange products.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is as follows: A steel-plastic composite pipe flange double-flaring self-aligning forming device includes a cavity forming part, a core forming part, a lifting mechanism, a feeding mechanism, a mold base and a frame, wherein the cavity forming part is arranged on the frame in front of the core forming part; The core forming section includes a horizontally arranged double-flaring mold and a self-aligning forming mold. The feeding mechanism includes a primary feeding mechanism and a secondary feeding mechanism. The lifting mechanism includes a core slide plate and a slide groove. The slide groove is longitudinally arranged on the mold base. The core slide plate is slidably installed in the slide groove and connected to the mold base through a lifting hydraulic cylinder. The mold base is set on the frame through the primary feeding mechanism. The double-flaring mold is connected to the core slide plate through the secondary feeding mechanism. The self-aligning forming mold is set on the core slide plate and located below the double-flaring mold.

[0006] Furthermore, the dual flaring mold includes a primary flaring mold and a secondary flaring mold arranged coaxially. The secondary flaring mold is slidably fitted on the outside of the primary flaring mold and connected to the flaring mold base through a three-stage feeding mechanism. The primary flaring mold is fixedly connected to the flaring mold base and connected to the mold core slide plate through the secondary feeding mechanism.

[0007] Furthermore, the primary flaring die includes a primary guide section, a primary conical flaring section, and a primary connecting section, which are fixedly connected from front to back. The secondary flaring die includes a secondary conical flaring section, a secondary connecting section, and a disc, which are fixedly connected from front to back. The tail end of the primary conical flaring section is adjacent to the head end of the secondary conical flaring section. The secondary conical flaring section and the secondary connecting section are slidably fitted onto the outside of the primary connecting section and fixedly connected to the disc. The disc is connected to the flaring die base through a three-stage feeding mechanism. The primary conical flaring section is fixedly connected to the flaring die base through the primary connecting section and is connected to the secondary feeding mechanism.

[0008] Furthermore, the self-aligning molding die includes a molding sleeve and a molding core. The tail end of the molding core is connected to the molding core slide plate through a model support and a molding core support. The molding sleeve is fitted onto the outside of the molding core. The head end of the molding core is fixed with a circular baffle that axially limits the molding sleeve by bolts. A self-aligning unit is provided between the molding sleeve and the molding core.

[0009] Furthermore, the self-aligning unit includes several self-aligning springs, which are evenly arranged circumferentially along the side wall of the forming mold core. The side wall of the forming mold core is provided with mounting holes for mounting the self-aligning springs, and the several self-aligning springs are elastically installed between the outer wall of the forming mold core and the inner wall of the forming sleeve.

[0010] Furthermore, a cooling channel is provided at the center of the molding core, and ventilation holes for cooling steel-plastic composite pipes are evenly opened on the side wall. The ventilation holes are connected to the cooling channel, and the cooling channel is connected to the air-cooling system.

[0011] Furthermore, the mold cavity forming part includes a positioning fixture group and a forming mold arranged adjacent to each other. The positioning fixture group is located on the side away from the mold core forming part. The positioning fixture group includes a positioning fixture. The positioning fixture is connected to a positioning hydraulic cylinder through a positioning semi-guide post. The positioning hydraulic cylinder is connected to the machine frame through the mold cavity base. The forming module includes a forming mold. The forming mold is connected to a forming hydraulic cylinder through a forming semi-guide post. The forming hydraulic cylinder is connected to the machine frame through the mold cavity base.

[0012] Furthermore, the forming mold has a stepped first mold cavity and a second mold cavity. The first mold cavity is located on the side away from the forming part of the mold core. The diameter of the first mold cavity and the positioning mold cavity inside the positioning fixture are equal to the outer diameter of the steel-plastic composite pipe. The diameter of the second mold is equal to the outer diameter of the flange of the steel-plastic composite pipe.

[0013] This invention also discloses a method for forming a double-flared self-aligning flange for steel-plastic composite pipes, comprising the following steps: Step 1: Mold selection. Select the appropriate mold cavity forming part according to the outer diameter of the steel-plastic composite pipe, and select the appropriate double flaring mold and self-aligning forming mold according to the inner diameter of the steel-plastic composite pipe. Step 2: Pipe heating. The end of the steel-plastic composite pipe to be formed is heated to a high elasticity state using a heating device. During the heating process, the pipe is rotated in both directions to ensure uniform heating of the pipe end. Step 3: Pipe clamping. Transfer the heated pipe to the forming part of the mold cavity for positioning and clamping. The transfer time shall not exceed 10 seconds. Step 4: Double flaring of pipe ends. The pipe end is flared twice using a double flaring mold. The first flaring makes the pipe end into a flared shape, and the second flaring changes the pipe end from a flared shape to a backward folded shape. Step 5: Self-aligning forming. The position of the double flaring mold and the self-aligning forming mold is switched by the lifting mechanism, and the self-aligning forming mold is pushed into the end of the pipe by the secondary feeding mechanism to automatically align and correct and gradually extrude and form the pipe. Step 6: Pipe end cooling. After the formed flange has cooled, the self-aligning forming mold is pulled out of the steel-plastic composite pipe by the secondary feeding mechanism, and the workpiece is removed.

[0014] Furthermore, the heating device in step 2 uses thermal radiation heating, with a heating temperature of 300-450℃ and a heating time of 5-8 minutes.

[0015] The present invention, by employing the above-described structure, achieves the following technological advancements compared to existing technologies: By using a double-flaring mold to flare the pipe ends twice, the steel-plastic composite pipe is formed into a trumpet shape. Then, the edges of the trumpet-shaped pipe ends are folded backward, altering the direction of the internal steel wires. This avoids exposed end wires during the flange forming process and makes the folded steel wire skeleton part of the flange, forming a reinforced skeleton integrated with the steel-plastic composite pipe, thus improving the connection strength between the flange and the pipe body. Furthermore, the self-aligning forming mold ensures smooth entry of the forming mold into the steel-plastic composite pipe, preventing material chipping and ensuring a smooth, stepless inner wall. This invention improves the mechanical properties and wear resistance of the steel-plastic composite pipe flange product, enhances its aesthetic appearance, meets the needs of domestic and international customers, and is applicable to the field of steel-plastic composite pipe processing technology. Attached Figure Description

[0016] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used together with the embodiments of the invention to explain the invention and do not constitute a limitation thereof.

[0017] In the attached diagram: Figure 1 This is a schematic diagram of the structure of an embodiment of the present invention; Figure 2 This is a front view of an embodiment of the present invention; Figure 3 This is a schematic cross-sectional view of the mold cavity forming part in an embodiment of the present invention; Figure 4 This is a schematic diagram of the core forming part in an embodiment of the present invention; Figure 5 This is a schematic diagram of the structure of the self-aligning molding die in an embodiment of the present invention; Figure 6 This is a schematic diagram of the structure of the double-flaring mold in an embodiment of the present invention; Figure 7 This is a schematic diagram of the two flaring and forming processes in an embodiment of the present invention.

[0018] Labeled components: 01-Mold cavity forming part, 11-Positioning fixture group, 12-Forming module, 110-Mold cavity base, 111-Positioning hydraulic cylinder, 112-Positioning semi-guide pillar, 113-Positioning fixture, 121-Forming hydraulic cylinder, 122-Forming semi-guide pillar, 123-Forming mold; 02-Lifting mechanism, 21-Lifting hydraulic cylinder, 22-Slide groove, 23-Mold core slide plate, 03-Mold core forming part, 31-Double flaring mold, 311-Flaring mold base, 312-Disc, 313-Secondary connecting section, 314-Secondary cylindrical flaring section, 315-Primary conical flaring section, 316-Primary guide section, 317-Hollow structure, 318-Threaded hole, 319-Primary connecting section, 32-Self-aligning forming mold, 321-Mold core support, 3210-Air pipe inlet, 322-Model support, 323-Forming mold core, 3230-Mounting hole, 3231-Ventilation hole, 324-Forming sleeve, 3240-Conical guide part, 3241-Forming pressure plate, 325-Baffle, 326-Bolt, 327-Self-aligning spring; 04-Rack, 05-Feed mechanism, 51-First hydraulic cylinder, 52-Pad block, 53-Slider, 54-Slide rod, 55-High pressure oil pipe, 551-High pressure oil cylinder, 56-Second hydraulic cylinder, 57-Guide column; 06-Mold base, 61-Mold base upper plate, 62-Mold base rear plate, 63-Mold base front plate, 64-Mold base bottom plate, 65-Support column. Detailed Implementation

[0019] The preferred embodiments of the present invention will now be described with reference to the accompanying drawings. It should be understood that the preferred embodiments described herein are for illustrative and explanatory purposes only and are not intended to limit the scope of the invention.

[0020] This invention discloses a double-flaring self-aligning forming device for steel-plastic composite pipe flanges, such as... Figure 1 As shown, it includes a cavity forming part 01, a core forming part 03, a lifting mechanism 02, a feeding mechanism 05, a mold base 06, and a frame 04. The cavity forming part 01 is mounted on the frame 04 in front of the core forming part 03. The actions of each mechanism are controlled by a PLC.

[0021] The core forming part 03 includes a horizontally arranged double-flaring mold 31 and a self-aligning forming mold 32. The feeding mechanism 05 includes a primary feeding mechanism and a secondary feeding mechanism. The lifting mechanism 02 includes a core sliding plate 23 and a slide groove 22. The slide groove 22 is longitudinally arranged on the mold base 06. The core sliding plate 23 is slidably installed in the slide groove 22 and is connected to the mold base 06 through a lifting hydraulic cylinder 21. The mold base 06 is set on the frame 04 through the primary feeding mechanism. The double-flaring mold 31 is connected to the core sliding plate 23 through the secondary feeding mechanism. The self-aligning forming mold 32 is set on the core sliding plate 23 and located below the double-flaring mold 31.

[0022] The feeding mechanism includes a first hydraulic cylinder 51, a pad 52, a slider 53, and a slide rod 54. The mold base 06 includes a mold base upper plate 61, a mold base bottom plate 64, a mold base front plate 63, and a mold base rear plate 62, which are fixedly connected. Six support columns 65 are fixed between the mold base front plate 63 and the mold base rear plate 62. Two slide rods 54 are provided at the bottom of the frame 04 through four pads 52. The mold base bottom plate 64 is slidably connected to the two slide rods 54 through four sliders 53. The mold base rear plate 62 is connected to the tail plate of the frame 04 through the first hydraulic cylinder 51. Specifically, the cylinder body of the first hydraulic cylinder 51 is hinged to the tail plate of the frame 04 through a hinge, and the piston end of the first hydraulic cylinder 51 is fixedly connected to the mold base front plate 63.

[0023] The secondary feeding mechanism includes a second hydraulic cylinder 56 and two guide pillars 57. The cylinder body of the second hydraulic cylinder 56 is fixed on the mold core slide plate 23. The piston end of the second hydraulic cylinder 56 is fixedly connected to the flaring mold base 311 and the primary flaring mold. At the same time, the flaring mold base 311 is provided with two guide pillars 57, and the mold core slide plate 23 is provided with guide sleeves that are adapted to the guide pillars 57.

[0024] During double flaring, the double flaring die 31 advances to a designated position under the push of the secondary feeding mechanism, flaring the pipe end twice. Specifically, the pipe end expands under the action of the primary flaring die, forming a flared shape; then, the secondary flaring die is pushed forward by the tertiary feeding mechanism to perform a secondary flaring, extruding the material at the edge of the flared pipe towards the direction of the conical die, changing the pipe end from a flared shape to a backward folded shape, thereby changing the direction of the steel wires inside the steel-plastic composite pipe and avoiding the phenomenon of exposed steel wires during the forming process.

[0025] After the two flaring processes are completed, the double flaring mold 31 retracts to the designated position with the secondary feeding mechanism. At the same time, the tertiary feeding mechanism resets, and the double flaring mold 31 and the self-aligning forming mold 32 rise under the pulling force of the lifting hydraulic cylinder 21, so that the self-aligning forming mold 32 rises to the designated position and is consistent with the height of the pipe, thus preparing for the self-aligning forming mold 32 to perform self-aligning forming.

[0026] As a specific embodiment of the present invention, as shown in the figure, the double flaring mold 31 includes a primary flaring mold and a secondary flaring mold arranged coaxially. The secondary flaring mold is slidably fitted on the outside of the primary flaring mold and connected to the flaring mold base 311 through a three-stage feeding mechanism. The primary flaring mold is fixedly connected to the flaring mold base 311 and connected to the mold core slide plate 23 through the secondary feeding mechanism.

[0027] Preferably, the primary flaring die includes a primary guide section 316, a primary conical flaring section 315, and a primary connecting section 319, which are fixedly connected from front to back. The three sections are integrally formed, and a hollow structure 317 is provided in the middle. The connection between the flaring die base 23 and the primary connecting section 319 is provided with a threaded hole 318 for connecting with the piston end of the second hydraulic cylinder 56. The secondary flaring die includes a secondary conical flaring section 314, a secondary connecting section 313, and a disc 312, which are fixedly connected from front to back. The three are integrally formed. The tail end of the primary conical flaring section 315 is adjacent to the head end of the secondary conical flaring section 314. The secondary conical flaring section 314 and the secondary connecting section 313 are slidably fitted on the outside of the primary connecting section 319 and fixedly connected to the disc 312. The disc 312 is connected to the flaring die base 311 through a three-stage feeding mechanism. The primary conical flaring section 315 is fixedly connected to the flaring die base 311 through the primary connecting section 319 and is connected to the secondary feeding mechanism. Specifically, the three-stage feeding mechanism includes a high-pressure hydraulic cylinder 551. The cylinder body of the high-pressure hydraulic cylinder 551 is fixed on the flaring die base 311, and its piston end passes through the flaring die base 311 and is fixedly connected to the disc 312. The high-pressure hydraulic cylinder 551 is connected to the high-pressure oil pipe 55. The running distance of the secondary flaring die relative to the primary flaring die is 30mm-100mm.

[0028] As shown in the figure, in a specific embodiment of the present invention, the self-aligning molding die 32 includes a molding sleeve 324 and a molding core 323. The molding sleeve 324 has a cylindrical structure with a tapered guide portion 3240 at its front end and a molding pressure plate 3241 at its rear end. The rear end of the molding core 323 is connected to the core slide plate 23 via a mold support 322 and a core support 321. The molding sleeve 324 is fitted onto the outside of the molding core 323. A circular baffle 325 for axially limiting the molding sleeve 324 is fixed to the front end of the molding core 323 by bolts 326. A self-aligning unit is provided between the molding sleeve 324 and the molding core 323. The outer diameter of the molding sleeve 324 is the same as the inner diameter of the steel-plastic composite pipe. The molding sleeve 324 is made of high-strength, low-weight material, and has a low surface roughness value, maintaining a smooth surface.

[0029] Preferably, the self-aligning unit includes a plurality of self-aligning springs 327, which are evenly arranged circumferentially along the side wall of the forming mold core 323. The side wall of the forming mold core 323 is provided with mounting holes 3230 for mounting the self-aligning springs 327, and the plurality of self-aligning springs 327 are elastically installed between the outer wall of the forming mold core 323 and the inner wall of the forming sleeve 324.

[0030] As shown in the figure, in a specific embodiment of the present invention, a cooling channel is provided at the center of the molding core 323, and ventilation holes 3231 for cooling the steel-plastic composite pipe are evenly opened on the side wall. The ventilation holes 3231 are connected to the cooling channel, and the cooling channel is connected to the air cooling system. The surface of the molding core 323 has ventilation holes 3231. During the molding process, the flange is cooled and formed through the ventilation holes 3231, which can shorten the cooling time of the flange and improve production efficiency. Specifically, the air cooling system blows air into the cooling channel of the molding core 323 through the cooling air pipe through the mold support 322 and the core support 321. The core support 321 has an air pipe inlet 3210 adapted to the cooling air pipe. The number and arrangement of the ventilation holes 3231 on the surface of the molding core 323 are specified according to the usage requirements.

[0031] As a specific embodiment of the present invention, as shown in the figure, the mold cavity forming part 01 includes a positioning fixture group 11 and a forming module 12 arranged adjacent to each other. The positioning fixture group 11 is located on the side away from the mold core forming part 03. The positioning fixture group 12 includes a positioning fixture 113, which is connected to a positioning hydraulic cylinder 111 through a positioning semi-guide post 112. The positioning hydraulic cylinder 111 is connected to the frame 04 through a mold cavity base 110. The forming module 12 includes a forming mold 123, which is connected to a forming hydraulic cylinder 121 through a forming semi-guide post 122. The forming hydraulic cylinder 121 is connected to the frame 04 through the mold cavity base 110.

[0032] Preferably, the molding die 12 has a stepped first mold cavity and a second mold cavity. The first mold cavity is located on the side away from the core forming part 03. The diameter of the first mold cavity and the positioning mold cavity inside the positioning fixture 11 is equal to the outer diameter of the steel-plastic composite pipe. The diameter of the second mold is equal to the outer diameter of the flange of the steel-plastic composite pipe.

[0033] This invention also discloses a method for forming a double-flared self-aligning flange for steel-plastic composite pipes. The method generally consists of two stages: heating and forming. The heating stage is consistent with existing steel-plastic composite pipe heating methods, where the inner and outer walls of the pipe ends are heated using a heating device to bring the inner and outer plastic layers to a highly elastic state. Subsequently, the forming stage uses a double-flared self-aligning device to form the heated pipe. The forming stage includes a double-flaring process and a self-aligning forming process. Specifically, the forming method includes the following steps: Step 1: Mold selection. Select the appropriate mold cavity forming part 01 according to the outer diameter of the steel-plastic composite pipe, and select the appropriate double flaring mold 31 and self-aligning forming mold 32 according to the inner diameter of the steel-plastic composite pipe. Step 2: Pipe heating. The end of the steel-plastic composite pipe to be formed is heated to a high elasticity state by a heating device. During the heating process, the pipe is rotated in both directions to ensure uniform heating of the pipe end. The heating device adopts thermal radiation heating, with a heating temperature of 300-450℃ and a heating time of 5-8 minutes.

[0034] Step 3: Clamping the pipe. Transfer the heated pipe to the forming part 01 of the mold cavity for positioning and clamping. The transfer time shall not exceed 10 seconds. Step 4: Double flaring of pipe end. The pipe end is flared twice using the double flaring mold 31. The first flaring makes the pipe end into a flared shape, and the second flaring changes the pipe end from a flared shape to a backward folded shape. Specifically, the double flaring process is as follows: First, a secondary feeding mechanism pushes the primary flaring die into the steel-plastic composite pipe for primary flaring. Then, without moving the primary flaring die, a tertiary feeding mechanism pushes the secondary flaring die for secondary flaring. Finally, both the primary and secondary flaring dies exit the forming section 01 of the mold cavity under the pulling force of the secondary feeding mechanism. The primary flaring die's function is to flare the pipe end of the steel-plastic composite pipe into a trumpet shape, while the secondary flaring die's function is to fold the edge of the trumpet-shaped pipe end backward, thereby preventing the end wires from being exposed during the flange forming process.

[0035] Step 5: Self-aligning forming. The lifting hydraulic cylinder 21 of the lifting mechanism 02 switches the position of the double flaring mold 31 and the self-aligning forming mold 32, and the self-aligning forming mold 32 is pushed into the end of the pipe by the primary feeding mechanism to automatically align and correct and gradually extrude and form. Specifically, the self-aligning molding process is as follows: First, the die holder 06 is moved forward by the primary feeding mechanism, so that the self-aligning forming die 32 enters the steel-plastic composite pipe. During the process of the self-aligning forming die 32 entering the steel-plastic composite pipe, the forming sleeve 324 is automatically corrected by the inner wall of the steel-plastic composite pipe. Because of the self-aligning spring 327 structure inside the forming sleeve 324, the forming sleeve 324 can swing relative to the forming die core 323 under small force. The forming sleeve 324 can swing freely on the surface of the forming die core 323 to achieve automatic self-aligning correction and ensure that the forming sleeve 324 enters the steel-plastic composite pipe smoothly. Then, when the flange root enters the first die cavity, the first die cavity corrects the forming sleeve 324 a second time. At the same time, the second die cavity corrects the edge of the flange and extrudes it under the action of the forming pressure plate 3241.

[0036] The self-aligning forming mold 32 avoids the occurrence of material scraping inside the steel-plastic composite pipe; at the same time, the outer diameter of the forming sleeve 324 in the self-aligning forming mold 32 is consistent with the inner diameter of the steel-plastic composite pipe, which can ensure that the inner wall of the steel-plastic composite pipe flange product is smooth and without steps.

[0037] Step 6: Pipe end cooling. After the formed flange has cooled, the self-aligning forming mold 32 is pulled out of the steel-plastic composite pipe by the primary feeding mechanism, and the workpiece is removed.

[0038] In summary, the steel-plastic composite pipe flange forming device and method provided by this invention flares the pipe twice using a double-flaring mold 31, forming the pipe end of the steel-plastic composite pipe into a trumpet shape. Then, the edge of the trumpet-shaped pipe end is folded backward, changing the direction of the internal steel wires in the composite pipe. On the one hand, this avoids the end steel wires being exposed during the flange forming process. Simultaneously, the folded steel wire skeleton becomes part of the flange, forming a reinforcing skeleton integral with the steel-plastic composite pipe, improving the connection strength between the flange and the pipe body. On the other hand, the self-aligning forming mold 32 ensures that the forming sleeve 324 smoothly enters the steel-plastic composite pipe, preventing material scraping inside the pipe and ensuring a smooth, stepless inner wall. This invention improves the mechanical properties and wear resistance of the steel-plastic composite pipe flange product, enhances its aesthetic appearance, meets the needs of domestic and international customers, and is applicable to the field of steel-plastic composite pipe processing technology.

[0039] Finally, it should be noted that the above descriptions are merely preferred embodiments of the present invention and are not intended to limit 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 make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. A double-flaring self-aligning forming device for steel-plastic composite pipe flanges, characterized in that: It includes a cavity forming section, a core forming section, a lifting mechanism, a feeding mechanism, a mold base, and a frame. The cavity forming section is located on the frame in front of the core forming section. The core forming part includes a horizontally arranged double-flaring mold and a self-aligning forming mold. The feeding mechanism includes a primary feeding mechanism and a secondary feeding mechanism. The lifting mechanism includes a core sliding plate and a slide groove. The slide groove is longitudinally arranged on the mold base. The core sliding plate is slidably installed in the slide groove and connected to the mold base through a lifting hydraulic cylinder. The mold base is set on the frame through the primary feeding mechanism. The double-flaring mold is connected to the core sliding plate through the secondary feeding mechanism. The self-aligning forming mold is set on the core sliding plate and located below the double-flaring mold. The self-aligning molding die includes a molding sleeve and a molding core. The tail end of the molding core is connected to the molding core slide plate through a model support and a molding core support. The molding sleeve is fitted on the outside of the molding core. The head end of the molding core is fixed with a circular baffle that axially limits the molding sleeve by bolts. A self-aligning unit is provided between the molding sleeve and the molding core. The self-aligning unit includes several self-aligning springs, which are evenly arranged circumferentially along the side wall of the forming mold core. The side wall of the forming mold core has mounting holes for installing the self-aligning springs, and the self-aligning springs are elastically installed between the outer wall of the forming mold core and the inner wall of the forming sleeve.

2. The steel-plastic composite pipe flange double-flaring self-aligning forming device according to claim 1, characterized in that: The dual flaring mold includes a primary flaring mold and a secondary flaring mold arranged coaxially. The secondary flaring mold is slidably fitted on the outside of the primary flaring mold and connected to the flaring mold base through a three-stage feeding mechanism. The primary flaring mold is fixedly connected to the flaring mold base and connected to the mold core slide plate through the secondary feeding mechanism.

3. The steel-plastic composite pipe flange double-flaring self-aligning forming device according to claim 2, characterized in that: The primary flaring die includes a primary guide section, a primary conical flaring section, and a primary connecting section, which are fixedly connected from front to back. The secondary flaring die includes a secondary conical flaring section, a secondary connecting section, and a disc, which are fixedly connected from front to back. The tail end of the primary conical flaring section is adjacent to the head end of the secondary conical flaring section. The secondary conical flaring section and the secondary connecting section are slidably fitted onto the outside of the primary connecting section and fixedly connected to the disc. The disc is connected to the flaring die base through a three-stage feeding mechanism. The primary conical flaring section is fixedly connected to the flaring die base through the primary connecting section and is connected to the secondary feeding mechanism.

4. The steel-plastic composite pipe flange double-flaring self-aligning forming device according to claim 1, characterized in that: The molding core is provided with a cooling channel at its center, and ventilation holes for cooling steel-plastic composite pipes are evenly opened on the side wall. The ventilation holes are connected to the cooling channel, and the cooling channel is connected to the air cooling system.

5. The steel-plastic composite pipe flange double-flaring self-aligning forming device according to claim 1, characterized in that: The mold cavity forming part includes a positioning fixture group and a forming module arranged adjacent to each other. The positioning fixture group is located on the side away from the mold core forming part. The positioning fixture group includes a positioning fixture, which is connected to a positioning hydraulic cylinder through a positioning semi-guide post. The positioning hydraulic cylinder is connected to the machine frame through the mold cavity base. The forming module includes a forming mold, which is connected to a forming hydraulic cylinder through a forming semi-guide post. The forming hydraulic cylinder is connected to the machine frame through the mold cavity base.

6. The steel-plastic composite pipe flange double-flaring self-aligning forming device according to claim 5, characterized in that: The forming mold has a stepped first mold cavity and a second mold cavity. The first mold cavity is located on the side away from the forming part of the mold core. The diameter of the first mold cavity and the positioning mold cavity inside the positioning fixture are equal to the outer diameter of the steel-plastic composite pipe. The diameter of the second mold is equal to the outer diameter of the flange of the steel-plastic composite pipe.

7. A method for forming a double-flared self-aligning flange for steel-plastic composite pipes, characterized in that... The method employs the double-flaring self-aligning forming device for steel-plastic composite pipe flanges as described in any one of claims 1-6, and includes the following steps: Step 1: Mold selection. Select the appropriate mold cavity forming part according to the outer diameter of the steel-plastic composite pipe, and select the appropriate double flaring mold and self-aligning forming mold according to the inner diameter of the steel-plastic composite pipe. Step 2: Pipe heating. The end of the steel-plastic composite pipe to be formed is heated to a high elasticity state using a heating device. During the heating process, the pipe is rotated in both directions to ensure uniform heating of the pipe end. Step 3: Pipe clamping. Transfer the heated pipe to the forming part of the mold cavity for positioning and clamping. The transfer time shall not exceed 10 seconds. Step 4: Double flaring of pipe ends. The pipe end is flared twice using a double flaring mold. The first flaring makes the pipe end into a flared shape, and the second flaring changes the pipe end from a flared shape to a backward folded shape. Step 5: Self-aligning forming. The position of the double flaring mold and the self-aligning forming mold is switched by the lifting mechanism, and the self-aligning forming mold is pushed into the end of the pipe by the secondary feeding mechanism to automatically align and correct and gradually extrude and form the pipe. Step 6: Pipe end cooling. After the formed flange has cooled, the self-aligning forming mold is pulled out of the steel-plastic composite pipe by the secondary feeding mechanism, and the workpiece is removed.

8. The method for forming a double-flared self-aligning flange for a steel-plastic composite pipe according to claim 7, characterized in that: The heating device in step 2 uses thermal radiation heating, with a heating temperature of 300-450℃ and a heating time of 5-8 minutes.

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