Plug for cast pipe lining
By using an inflatable rubber ring to form a chamfered plug structure at the spigot end of the ductile iron pipe, the problem of dealing with the protruding spigot end of the cement lining of the ductile iron pipe is solved. This eliminates the need for the chamfering process, reduces production costs and scrap rate, and improves production efficiency.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- WUHU XINXING DUCTILE IRON PIPES
- Filing Date
- 2025-04-21
- Publication Date
- 2026-04-28
AI Technical Summary
The existing technology for treating the protruding spigot end of the cement-lined ductile iron pipe requires an additional chamfering process, which makes the spigot end susceptible to damage during production, increases the scrap rate and production costs, and requires equipment adjustment for different pipe specifications, reducing production efficiency.
The plug structure includes a skeleton body and first and second inflatable rubber rings. By inflating, the rubber rings are made to fit against the outer and inner walls of the cast pipe, forming an inner chamfer. This eliminates the chamfering process and achieves both fixing and chamfering while adapting to the production needs of pipes of different specifications.
Accelerate the production process, reduce processing costs, improve the integrity of finished pipes and reduce scrap rates, reduce material shortages and flash defects, and improve production efficiency.
Smart Images
Figure CN224167921U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of cast pipe lining technology, and specifically to a plug for cast pipe lining. Background Technology
[0002] In the centrifugal casting of ductile iron pipes, an internal anti-corrosion lining is required, with acidic cement being a common process. During this cement lining process, the spigot end needs to be sealed, and there are standards for the quality of the spigot end's vertical surface molding. The cement surface must not protrude beyond the spigot end of the cast iron pipe and must form a chamfer with it.
[0003] Currently, the common practice in the ductile iron pipe industry for chamfering the inner lining is to add a chamfering process after the inner lining has cured and exited the furnace. This requires the use of chamfering equipment to chamfer the lining. However, during the transfer of the lined ductile iron pipe to the chamfering station, the spigot end is easily bumped, leading to insufficient material in the lining or cracks, increasing the scrap rate. Furthermore, when producing ductile iron pipes of different specifications, the chamfering equipment also needs to be adjusted and regularly inspected and maintained, which not only increases production costs but also reduces production efficiency. Utility Model Content
[0004] The purpose of this invention is to at least solve one of the technical problems existing in the prior art, and to provide a plug for lining cast iron pipes. This plug can eliminate the need for subsequent chamfering of the inner lining of the spigot end of the ductile iron pipe, thereby speeding up the production process and saving processing costs.
[0005] To achieve the above objectives, this utility model provides a plug for lining cast pipes, comprising:
[0006] The main body of the skeleton includes an end plate and an annular plate disposed on one side of the end plate. The inner wall of the annular plate is provided with a first annular groove, and the side of the end plate near the annular plate is provided with a second annular groove.
[0007] The first inflatable rubber ring is embedded in the first annular groove and is used to inflate and expand to fit and press against the outer wall of the cast pipe.
[0008] The second inflatable rubber ring is embedded in the second annular groove. The second inflatable rubber ring is used to inflate and expand to fit against the inner wall of the cast pipe and form an inner lining chamfer.
[0009] Optionally, the first inflatable rubber ring includes a first inner cavity and a first valve core communicating with the first inner cavity.
[0010] Optionally, the groove wall of the first annular groove near the end plate is provided with a vertical through notch, which is used for the passage of the first valve core.
[0011] Optionally, the second inflatable rubber ring includes a second inner cavity, a second valve core communicating with the second inner cavity, and a chamfered molding surface disposed on the side of the second inflatable rubber ring away from the end plate.
[0012] Optionally, the bottom surface of the second annular groove is provided with a through hole for the passage of the second valve core.
[0013] Optionally, the notch is in communication with the second annular groove.
[0014] Optionally, the end plate has a through hole at its center.
[0015] Optionally, the end plate is provided with a first annular wall and a second annular wall that extend vertically and have progressively smaller diameters on the side away from the cast pipe, and the first annular wall and the second annular wall are concentrically arranged with the through hole.
[0016] Optionally, the ends of both the first valve core and the second valve core are lower than the end face of the first annular wall or the second annular wall that is away from the end plate.
[0017] Optionally, the chamfered surface forms an angle of 7° with the horizontal plane.
[0018] Through the above technical solution, the first inflatable rubber ring is embedded in the first annular groove of the skeleton body. After inflation, it expands and fits tightly against the outer wall of the ductile iron pipe. Together with the skeleton body, it tightly connects the plug to the spigot end of the ductile iron pipe. The second inflatable rubber ring is embedded in the second annular groove of the skeleton body. After inflation, it expands and fits against the inner wall of the ductile iron pipe to form an inner lining chamfer. Then, it enters the coating production process. After the coating is completed, the inner lining of the spigot end of the ductile iron pipe forms a spigot surface with a chamfer. Attached Figure Description
[0019] Figure 1 This is a first-view overall structural diagram of a plug for coating cast pipe provided by this utility model;
[0020] Figure 2 This is a second-view overall structural diagram of a plug for coating cast pipe provided by this utility model;
[0021] Figure 3 This is a schematic diagram of the main skeleton of this utility model;
[0022] Figure 4 This is a schematic diagram of the structure of the first inflatable rubber ring in this utility model;
[0023] Figure 5 This is a schematic diagram of the structure of the second inflatable rubber ring in this utility model;
[0024] Figure 6 yes Figure 5 The front view.
[0025] Explanation of reference numerals in the attached figures
[0026] 1. Main frame; 11. End plate; 12. Ring plate; 13. First ring groove; 14. Second ring groove; 15. Through hole; 16. Notch; 17. Through hole; 18. First annular wall; 19. Second annular wall; 2. First inflation rubber ring; 21. First valve core; 3. Second inflation rubber ring; 31. Second valve core; 32. Chamfered surface. Detailed Implementation
[0027] The specific embodiments of this utility model will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are for illustration and explanation only and are not intended to limit the scope of this utility model.
[0028] Combination Figure 1 , Figure 2 as well as Figure 3 As shown, this utility model discloses a plug for lining cast pipes. The plug includes a skeleton body 1, a first inflatable rubber ring 2, and a second inflatable rubber ring 3. Specifically, the skeleton body 1 includes an end plate 11 and an annular plate 12 disposed on one side of the end plate 11. The inner wall of the annular plate 12 is provided with a first annular groove 13, and the side of the end plate 11 near the annular plate 12 is provided with a second annular groove 14. The first inflatable rubber ring 2 is embedded in the first annular groove 13 and is used for inflation to fit and press against the outer wall of the cast pipe. The second inflatable rubber ring 3 is embedded in the second annular groove 14 and is used for inflation to fit against the inner wall of the cast pipe and form an inner lining chamfer.
[0029] In this invention, the plug is installed at the inlet end of a ductile iron pipe. The material of the plug frame body 1 can be nylon or other high-strength materials. The frame body 1 is fitted onto the inlet end of the ductile iron pipe and is used to install and position the first inflation ring 2 and the second inflation ring 3. Its end plate 11 is in contact with the end face of the ductile iron pipe, and its ring plate 12 is in contact with the outer wall of the ductile iron pipe, ensuring the installation and positioning accuracy of the plug on the ductile iron pipe. The second annular groove 14 and the first annular groove 13 are used to embed the second inflation ring 3 and the first inflation ring 2, respectively, so that the installation positions of the first inflation ring 2 and the second inflation ring 3 are accurate and stable, ensuring that the rings can function correctly after inflation.
[0030] It is understandable that the size and shape of the first annular groove 13 and the second annular groove 14 should match the first inflatable rubber ring 2 and the second inflatable rubber ring 3 respectively, to ensure that the first inflatable rubber ring 2 and the second inflatable rubber ring 3 can be smoothly installed.
[0031] The first inflatable rubber ring 2 can be made of rubber and is used to fix the plug to the spigot end of the ductile iron pipe in conjunction with the main body 1 of the frame. The second inflatable rubber ring 3 can also be made of rubber and is used to form an inner chamfer after the spigot end of the ductile iron pipe expands and deforms.
[0032] As can be seen from the above technical solution description, the inventive concept of this utility model is to fix two inflatable rubber rings that achieve the functions of fixing and chamfering on a frame body 1 to simultaneously achieve the fixing of the plug and the chamfering of the inner lining. The second inflatable rubber ring 3 with corresponding parameters can be replaced according to different inner lining chamfering parameters, without replacing the entire plug, so as to achieve various specifications of inner lining chamfering that meet production requirements.
[0033] Furthermore, by using the plug in this invention, the subsequent chamfering process of the inner lining of the casting pipe spigot end can be omitted, which speeds up the production process and saves processing costs. Compared with the plug forming condition in the prior art, the cement inner lining surface of the casting pipe spigot end after using the plug of this invention is more uniform and complete, the probability of defects such as material shortage and flash is significantly reduced, and the scrap rate of finished pipes is reduced, thereby reducing the overall production cost.
[0034] In summary, the specific operation process of the plug in this utility model is as follows:
[0035] First, the main frame 1, the first inflatable rubber ring 2, and the second inflatable rubber ring 3 are assembled. During production, the installed plug is placed on the spigot end of the ductile iron pipe. The first inflatable rubber ring 2 is inflated to expand and tightly wrap around the outer wall of the spigot end of the ductile iron pipe. Then, the second inflatable rubber ring 3 is inflated. After the second inflatable rubber ring 3 expands and deforms, it adheres to the inner wall of the pipe and forms an inner lining chamfer. Then, the lining process begins. After the lining material dries and cures, the second inflatable rubber ring 3 is deflated and then removed from the cast pipe, thus completing the entire operation.
[0036] Specifically, in this utility model, such as Figure 4 As shown, the first inflatable rubber ring 2 includes a first inner cavity and a first valve core 21 communicating with the first inner cavity. The first valve core 21 is used to connect an inflation device to inflate the first inner cavity with an expansion medium, so that the first inflatable rubber ring 2 expands and presses against the outer wall of the cast pipe. Figure 5 and Figure 6 As shown, the second inflatable rubber ring 3 includes a second inner cavity, a second valve core 31 communicating with the second inner cavity, and a chamfered forming surface 32 disposed on the side of the second inflatable rubber ring 3 away from the end plate 11. The second valve core 31 is used to connect the inflation device to fill the second inner cavity with an expansion medium so that the second inflatable rubber ring 3 expands and fits against the inner wall of the cast pipe to form an inner lining chamfer.
[0037] Furthermore, in this utility model, to facilitate the inflation operation of the first inflation ring 2 and the second inflation ring 3, such as... Figure 3 As shown, the first annular groove 13 has a vertical through-hole 16 on the side of the groove wall near the end plate 11, which allows the first valve core 21 to pass through. The bottom surface of the second annular groove 14 has a through hole 15 for the second valve core 31 to pass through.
[0038] Furthermore, due to the limited height of the first annular groove 13 and the small space of the notch 16, the position of the first valve core 21 may slightly shift during the inflation of the first inflatable rubber ring 2. Due to the limited space, the first valve core 21 may not align with the inflation port of the inflation device, resulting in leakage during inflation. Therefore, the notch 16 in this invention can be configured to communicate with the second annular groove 14, allowing the notch 16 to extend to the bottom surface of the second groove, increasing the area of the notch 16 and preventing leakage during inflation of the first inflatable rubber ring 2. In addition, the design of the notch 16 also facilitates the disassembly and replacement of the first inflatable rubber ring 2 and the second inflatable rubber ring 3.
[0039] In this utility model, such as Figure 2 As shown, a through hole 17 is provided in the center of the end plate 11. The through hole 17 is used so that the cement feeding pipe can extend into the interior of the cast pipe during the lining process. In addition, the through hole 17 can also serve as a handle to facilitate manual installation or removal of the plug from the cast pipe.
[0040] In this utility model, such as Figure 2 As shown, the end plate 11 has a first annular wall 18 and a second annular wall 19 extending vertically and decreasing in diameter sequentially on the side away from the casting pipe. The first annular wall 18 and the second annular wall 19 are concentrically arranged with the through hole 17. Furthermore, the ends of the first valve core 21 and the second valve core 31 are both lower than the end face of the first annular wall 18 or the second annular wall 19 away from the end plate 11.
[0041] Understandably, the notch 16 for the first valve core 21 to extend and the through opening for the second valve core 31 to extend both penetrate the entire end plate 11. The ends of the first valve core 21 and the second valve core 31 are on the same side of the end plate 11 as the first annular wall 18 and the second annular wall 19. Their ends are set to be lower than the end face of the first annular wall 18 or the second annular wall 19 that is far away from the end plate 11. In this way, the annular wall not only provides a physical barrier for the valve core, which can effectively resist external impact, but also reduces the risk of valve core damage caused by accidental contact. This facilitates the smooth connection between the valve core and the external air source and extends the service life of the valve core.
[0042] In addition, by setting up multiple annular wall structures with progressively smaller ring diameters, the overall weight of the plug is reduced while ensuring the overall structural strength of the plug, thereby improving the flexibility of the plug in use.
[0043] In this utility model, the chamfered forming surface 32 has an angle of 7° with the horizontal plane. It can be understood that the chamfered forming surface 32 has an angle of 7° with the horizontal plane as an embodiment of an inner lining chamfer, and the angle can be adjusted according to the parameter requirements of the inner lining chamfer.
[0044] The preferred embodiments of the present invention have been described in detail above with reference to the accompanying drawings; however, the present invention is not limited thereto. Within the scope of the technical concept of the present invention, various simple modifications can be made to the technical solution of the present invention, including the combination of various specific technical features in any suitable manner. To avoid unnecessary repetition, the present invention will not describe the various possible combinations separately. However, these simple modifications and combinations should also be considered as the content disclosed in the present invention and are all within the protection scope of the present invention.
Claims
1. A plug for lining cast pipes, characterized in that, include: The main body of the skeleton (1) includes an end plate (11) and an annular plate (12) disposed on one side of the end plate (11). The inner wall of the annular plate (12) is provided with a first annular groove (13), and the end plate (11) is provided with a second annular groove (14) on the side close to the annular plate (12). The first inflatable rubber ring (2) is embedded in the first annular groove (13) and is used to inflate and expand to fit and press against the outer wall of the cast pipe. The second inflatable rubber ring (3) is embedded in the second annular groove (14). The second inflatable rubber ring (3) is used to inflate and expand to fit against the inner wall of the cast pipe and form an inner lining chamfer.
2. The plug for lining cast pipes according to claim 1, characterized in that, The first inflatable rubber ring (2) includes a first inner cavity and a first valve core (21) communicating with the first inner cavity.
3. The plug for lining cast pipes according to claim 2, characterized in that, The first annular groove (13) has a vertical through notch (16) on the side of the groove near the end plate (11), and the notch (16) is used for the passage of the first valve core (21).
4. The plug for lining cast pipes according to claim 3, characterized in that, The second inflatable rubber ring (3) includes a second inner cavity, a second valve core (31) communicating with the second inner cavity, and a chamfered molding surface (32) disposed on the side of the second inflatable rubber ring (3) away from the end plate (11).
5. The plug for lining cast pipes according to claim 4, characterized in that, The bottom surface of the second annular groove (14) is provided with a through hole (15) for the second valve core (31) to pass through.
6. The plug for lining cast pipes according to claim 3, characterized in that, The notch (16) is connected to the second annular groove (14).
7. The plug for lining cast pipes according to claim 5, characterized in that, The end plate (11) has a through hole (17) at its center.
8. The plug for lining cast pipes according to claim 7, characterized in that, The end plate (11) is provided with a first annular wall (18) and a second annular wall (19) that extend vertically and have successively smaller annular diameters on the side away from the cast pipe. The first annular wall (18) and the second annular wall (19) are arranged concentrically with the through hole (17).
9. The plug for lining cast pipes according to claim 8, characterized in that, The ends of the first valve core (21) and the second valve core (31) are both lower than the end face of the first annular wall (18) or the second annular wall (19) away from the end plate (11).
10. The plug for lining cast pipes according to claim 4, characterized in that, The chamfered surface (32) has an angle of 7° with the horizontal plane.