Stamping die for necking of steel pipe

Abstract

The utility model belongs to the technical field of steel pipe forming, and particularly relates to a stamping die for steel pipe necking. Comprising an upper die base, an upper die driving punch, a lower die base, an outer guide column, a core rod, a core rod fixing block, a female die block and a spring box assembly. The upper die driving punch is fixed on the upper die base, the upper die base is connected with the lower die base through an outer guide column, the core rod fixing block is installed on the lower die base, the core rod is fixed on the core rod fixing block through a bolt, the core rod is used for penetrating through a to-be-shaped steel pipe, the concave die block is installed on the lower die base in a sliding mode, and the concave die block is fixed on the lower die base through a bolt. The spring box assembly is used for resetting the female die block and installed on the lower die base through a bolt. The punch and the female die block are driven by the upper die to punch the necking of the steel pipe to be shaped, and the purpose of punch forming of the vertical necking of the steel pipe is achieved.

Description

Technical Field

[0001] This utility model belongs to the field of steel pipe forming technology, specifically relating to a stamping die for narrowing the end of a steel pipe. Background Technology

[0002] In the field of steel pipe forming technology, especially for steel pipe products that require necking, traditional processing methods often suffer from low efficiency, low precision, and low yield. Previous steel pipe necking processes typically relied on manual operation or simple mechanical equipment. This method is not only labor-intensive but also makes it difficult to guarantee the dimensional accuracy and surface quality of the product, especially when processing high-strength materials or large steel pipes. Furthermore, traditional necking molds are complex in design, have high maintenance costs, and are prone to wear during actual production, resulting in short mold life and increased production costs.

[0003] To address these issues, various types of automated steel pipe necking equipment have gradually emerged in the market. However, most existing automatic necking devices suffer from complex structures and inconvenient adjustments, particularly in the design of the molds, which fails to fully consider the versatility and adaptability of steel pipes of different specifications. For example, while some existing necking molds can improve work efficiency to a certain extent, the lack of effective guiding mechanisms and reset mechanisms makes them prone to deviation or jamming during the stamping process, affecting the final product quality.

[0004] Chinese Patent CN107511425A discloses a pipe fitting stamping and compression die, relating to the field of stamping die technology. It includes an upper die plate and a lower die base. A support block is fixed to the lower die base, and a lower groove is formed on the upper surface of the support block. A sliding die is connected to the lower die base, and the sliding die slides with the lower die base. One end of the sliding die facing the support block has a constricted cavity, and the other end is connected to a fixing plate fixed to the lower die base via a first spring. A wedge is provided on the upper die plate, and the opposite surfaces of the wedge and the sliding die are respectively the upper inclined surface and the lower inclined surface, which slide with each other. A pressure block is connected to the upper die plate via a second spring, and the lower surface of the pressure block has an upper groove opposite to the lower groove. The above device cannot stamp long steel pipes, and it lacks an external guide post, resulting in low precision between the wedge and the sliding die. Therefore, those skilled in the art urgently need to solve the above technical problems. Summary of the Invention

[0005] The technical problem to be solved by the present invention is that the prior art cannot stamp long steel pipes, and the device does not have an external guide post, resulting in low precision between the wedge and the sliding die.

[0006] To solve the above-mentioned technical problems, the technical solutions adopted by this utility model are as follows:

[0007] A stamping die for narrowing steel pipes includes an upper die base, an upper die drive punch, a lower die base, an outer guide post, a mandrel, a mandrel fixing block, a concave module, and a spring box assembly. The upper die drive punch is fixed on the upper die base, the upper die base is connected to the lower die base via the outer guide post, the mandrel fixing block is mounted on the lower die base, the mandrel is fixed to the mandrel fixing block by bolts, the mandrel is used to penetrate the steel pipe to be shaped, the concave module is slidably mounted on the lower die base, and the spring box assembly is used for resetting the concave module. The spring box assembly is mounted on the lower die base by bolts.

[0008] By adopting the above technical solution, the accurate alignment between the upper and lower die bases is ensured through the external guide pillars, guaranteeing precision in each stamping process. This is crucial for producing high-quality, consistent products. The upper die drive punch is fixed on the upper die base and connected to the lower die base via the external guide pillars, providing a stable frame for the entire mold. This helps withstand the forces generated during high-pressure stamping, reducing the risk of deformation. The mandrel can be bolted to the mandrel fixing block, meaning that the mandrel can be quickly replaced according to steel pipes of different diameters or specifications, increasing the mold's versatility and flexibility. The concave module adopts a sliding design combined with a spring box assembly for reset, simplifying the operation process and improving work efficiency. Simultaneously, this design facilitates maintenance and cleaning. Using the mandrel to penetrate the steel pipe to be shaped maintains the internal shape of the steel pipe during the necking process, preventing uneven deformation of the pipe wall caused by external pressure, thereby improving the quality of the final product.

[0009] Furthermore, an upper mold nitrogen spring is also provided on the upper mold base. The upper mold nitrogen spring is fixed to the bottom of the upper mold base by bolts and is located directly above the mandrel fixing block.

[0010] By employing the above technical solution, nitrogen springs can provide a very stable force value, which helps to maintain consistent pressure during the stamping process, thereby ensuring the accuracy and repeatability of each stamping operation. This stability is particularly important for high-precision steel pipe necking operations, where high-speed contact during stamping often generates significant impacts and vibrations. These not only affect product quality but may also shorten mold life. Nitrogen springs can absorb some of the impact energy, reducing damage to molds and other components, and extending equipment life. Because the pressure provided by nitrogen springs is more uniform and controllable, the entire stamping process is smoother, reducing potential jamming or blockages and improving production efficiency. Using nitrogen springs during stamping can reduce sudden energy peaks, thereby reducing safety risks caused by unexpected situations and protecting operator safety.

[0011] Furthermore, the outer guide post includes an outer guide post and an inner guide post, the outer guide post is located between the upper mold base and the lower mold base, and the mandrel fixing block is slidably mounted on the inner guide post.

[0012] By adopting the above technical solution, the mandrel fixing block, located between the upper and lower mold bases, is mainly used to ensure good alignment of the entire mold during closing and opening, reducing mold wear and product quality problems caused by misalignment. The mandrel fixing block can be slidably installed on it, providing a more precise guiding function. Especially when performing high-precision necking operations, it can ensure the accuracy and stability of the mandrel position. The double-layer guiding structure makes the mold more stable and resistant to off-center loads during operation. Especially when processing harder materials or requiring larger stamping pressure, it can effectively avoid misalignment or damage between mold components. Due to the combined action of the inner and outer guide pillars, the direct friction and impact between the components are reduced, which helps to reduce the wear rate and thus extend the overall service life of the mold. A more precise guiding system means that the expected effect can be achieved with each stamping, reducing the adjustment and correction time and improving production efficiency.

[0013] Furthermore, the lower mold base is also provided with a die guide block, a lower mold fixing plate, a limiting bolt, and a die reset guide block. The die module is slidably mounted on the die guide block. The die module reset guide block is connected to the die module through the spring box assembly. One end of the spring box assembly is connected to the threaded hole of the die module through a bolt, and the other end abuts against the die reset guide block. The lower mold fixing plate is mounted on the lower mold base. The limiting bolt is threaded onto the lower mold fixing plate. The head of the limiting bolt limits the upward height of the mandrel fixing block.

[0014] By adopting the above technical solution, the concave module is slidably installed on the concave die guide block, ensuring the consistency of the concave module's position during each stamping, improving the dimensional accuracy and shape consistency of the product. Precise guidance reduces friction between the concave module and other components, thereby reducing wear rate and extending the mold's service life. One end of the spring box assembly is connected to the concave module, and the other end rests on the concave die reset guide block. After one stamping is completed, the spring force helps the concave module to quickly reset, ensuring the stability and efficiency of continuous operation. During the stamping process, the spring can play a certain buffering role, reducing the impact on the mold and protecting the mold structure from damage. The lower die fixing plate is installed on the lower die base, increasing the rigidity and stability of the entire mold structure, making the working process smoother. The limit bolt is installed on the lower die fixing plate through threads, and its head limits the upward height of the mandrel fixing block, which can accurately control the working stroke of the mold, prevent over-stamping or under-stamping, and ensure product quality.

[0015] Furthermore, the upper die driving punch has a trapezoidal structure, and the concave module also has a trapezoidal structure, with the upper die driving punch and the concave module being adapted to each other.

[0016] Furthermore, a spring is provided between the mandrel fixing block and the lower mold base, with one end of the spring fixed inside the lower mold base and the other end in contact with the mandrel fixing block.

[0017] This utility model has the following beneficial effects:

[0018] 1. This utility model employs a double-layer guiding structure combining outer and inner guide pillars, ensuring not only accurate alignment between the upper and lower die bases but also high-precision stability of the mandrel fixing block position. This design significantly reduces wear caused by misalignment, enabling extremely high repeatability and consistency in each stamping operation, thereby greatly improving the dimensional accuracy and shape consistency of the product. The stabilizing force provided by the nitrogen spring plays a crucial role in the stamping process. Its uniform and controllable pressure characteristics ensure consistent high-quality standards in each stamping operation. Especially in the high-precision steel pipe necking process, this helps prevent uneven deformation of the pipe wall, ensuring the internal and external quality of the final product and improving product consistency and reliability.

[0019] 2. This utility model, through bolt fixing, allows for quick replacement of mandrels according to steel pipes of different diameters or specifications, increasing the adaptability of the mold and enabling it to handle products of various specifications. It also greatly shortens adjustment time and improves production efficiency. Components such as the concave module and spring box assembly adopt a sliding installation design, combined with bolt connection, which simplifies the disassembly and assembly process, facilitates daily maintenance and cleaning, improves work efficiency, reduces maintenance costs, and extends the service life of the equipment. It also facilitates rapid fault diagnosis and repair, further ensuring the continuity of production.

[0020] 3. This utility model achieves automatic reset of the concave module and mandrel fixing block by setting up a spring box assembly and springs. This not only accelerates the recovery speed after a single stamping but also ensures the stability and efficiency of continuous operation, improves production cycle time, reduces downtime, and enhances overall production capacity. Furthermore, the automatic reset mechanism reduces the need for human intervention, further improving automation and production efficiency. The nitrogen spring and spring design effectively absorb some of the impact energy during the stamping process, reducing the risk of damage to the mold and other components, extending the service life of the equipment. More stable working conditions mean higher production continuity and lower safety risks, which is crucial for long-term stable production. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the structure of this utility model;

[0022] Figure 2 This is a schematic diagram of the stamping structure of the steel pipe inserted into the mandrel of this utility model.

[0023] Figure 3 This utility model presents a schematic diagram of the stamping structure when the nitrogen spring of the upper mold contacts the core rod fixing block.

[0024] Figure 4 This is a schematic diagram of the stamping structure when the upper die drives the punch to contact the concave module.

[0025] Figure 5 This is a schematic diagram of the stamping structure of the present invention when the upper die drives the punch to push the concave module and form the steel pipe by narrowing the end of the pipe.

[0026] Figure 6 This is a schematic diagram of the stamping structure of the present invention when the upper die drives the punch to slowly detach from the concave module and detach the concave module from the steel pipe after the narrowing is completed.

[0027] Figure 7 This is a schematic diagram of the stamping structure after the mandrel fixing block drives the mandrel and the already shortened steel pipe to move upward when the steel pipe narrowing is completed.

[0028] Among them, 1-steel pipe to be narrowed; 2-outer guide post; 3-upper die nitrogen spring; 4-upper die base; 5-upper die drive punch; 6-concave module; 7-concave die guide block; 8-concave die reset guide block; 9-spring box assembly; 10-lower die base; 11-core rod; 12-core rod fixing block; 13-lower die fixing plate; 14-spring; 15-limiting bolt; 16-inner guide post. Detailed Implementation

[0029] The present invention will now be described in further detail with reference to the accompanying drawings and specific preferred embodiments.

[0030] In the description of this utility model, it should be understood that the terms "left side," "right side," "upper part," "lower part," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or component referred to must have a specific orientation, or be constructed and operated in a specific orientation. "First," "second," etc., do not indicate the importance of the components, and therefore should not be construed as a limitation of this utility model. The specific dimensions used in this embodiment are only for illustrating the technical solution and do not limit the protection scope of this utility model.

[0031] Reference Figure 1 , Figure 2 , Figure 3 , Figure 4 , Figure 5 , Figure 6 and Figure 7 As can be seen, the present invention provides a stamping die for narrowing the end of a steel pipe, which is connected from top to bottom as follows: outer guide post 2, upper die nitrogen spring 3, upper die base 4, upper die drive punch 5, concave module 6, concave die guide block 7, concave die reset guide block 8, spring box 9, lower die base 10, mandrel 11, mandrel fixing block 12, lower die fixing plate 13, spring 14, limit bolt 15 and inner guide post 16. During operation, the steel pipe 1 to be narrowed is fitted onto the mandrel 11; the upper die descends along the outer guide post 2, and the upper die nitrogen spring 3 contacts the mandrel fixing block 12; the upper die continues to descend, and because the compressive force of the upper die nitrogen spring 3 is greater than that of the springs 14 on the lower mandrel fixing block 12 and the lower die fixing plate 13, the mandrel fixing block 12, along with the mandrel 11 and the steel pipe 1, descends along the inner guide post 16 with the upper die; the upper die, the mandrel fixing block 12, the mandrel 11, and the steel pipe 1 continue to descend until the mandrel fixing block 12 contacts the lower die fixing block 13 and stops descending, at which point the upper die drive punch 5 begins to contact the concave module 6; the upper die continues to descend, and due to the action of the mandrel fixing block 12, the mandrel 11, and the steel pipe 1 on the lower die fixing block 13... The downward movement of the upper die stops, the nitrogen spring 3 of the upper die begins to compress, and the upper die drive punch 5 continues to move downward. The upper die drive punch 5 pushes the concave module 6 to slide to the left along the guide groove of the concave die guide block 7. Since one end of the concave module 6 is connected to the spring box assembly 9 by a thread, the spring box assembly 9 is pulled by the concave module 6 and begins to compress. The upper die continues to move downward, the nitrogen spring 3 of the upper die presses against the mandrel fixing block 12 and continues to be compressed. The upper die drive punch 5 follows the upper die and continues to move downward, pushing the concave module 6 to slide to the left along the guide groove of the concave die guide block 7 and begin to form the necking of the steel pipe 1. The spring box assembly 9 continues to be pulled and compressed by the concave module 6. The upper die stops moving downward, and the concave module 6 completes the necking of the steel pipe 1. The upper die begins to move upward along the outer guide post 2. The upper die nitrogen spring 3 slowly relaxes and continues to hold the mandrel fixing block 12, mandrel 11, and steel pipe in their original positions. The upper die drive punch 5 moves upward with the upper die and disengages from the concave module 6. Under the compressive force of the spring box assembly 9, the concave module 6 is pulled by the bolts of the spring box assembly 9 and begins to slide to the right along the guide groove of the concave die guide block 7, and disengages from the narrowed steel pipe. The upper die continues to move upward, and the upper die nitrogen spring 3 moves upward with it and disengages from the mandrel fixing block 12. Under the compressive force of the spring 14 below it, the mandrel fixing block 12 begins to move upward along the inner guide post 16, driving the mandrel 11 and the narrowed steel pipe until it reaches the head of the limit bolt 15 and stops moving upward. The narrowed steel pipe is manually pulled out, completing the narrowing of the steel pipe 1. This structure can meet the stamping requirements of long steel pipes that need to be narrowed but cannot be narrowed vertically. It can also easily insert or remove the steel pipe to be narrowed or the steel pipe that has been narrowed from the side. The structure is simple and easy to manufacture.

[0032] The process of using the mold of this invention is as follows:

[0033] A. Place the steel pipe 1 to be shrunk onto the mandrel 11.

[0034] B. The upper mold moves downward along the outer guide post 2, and the nitrogen spring 3 of the upper mold contacts the core rod fixing block 12.

[0035] C. The upper mold continues to descend. Since the compression force of the nitrogen spring 3 of the upper mold is greater than that of the spring 14 on the lower mandrel fixing block 12 and the lower mold fixing plate 13, the mandrel fixing block 12, along with the mandrel 11 and the steel pipe 1, descends along the inner guide post 16 with the upper mold.

[0036] D. The upper die, the mandrel fixing block 12, the mandrel 11, and the steel pipe 1 continue to descend until the mandrel fixing block 12 contacts the lower die fixing block 13 and stops descending. At this time, the upper die driving punch 5 begins to contact the concave module 6.

[0037] E. The upper die continues to descend. Due to the action of the lower die fixing block 13, the mandrel 11 and the steel pipe 1, along with the mandrel fixing block 12, stop descending. The nitrogen spring 3 of the upper die begins to compress, while the upper die drive punch 5 continues to descend. The upper die drive punch 5 pushes the concave module 6 to slide to the left along the guide groove of the concave die guide block 7. Since one end of the concave module 6 is connected to the spring box assembly 9 by a thread, the spring box assembly 9 is pulled by the concave module 6 and begins to compress.

[0038] F. The upper die continues to descend, the nitrogen spring 3 of the upper die presses against the mandrel fixing block 12 and continues to be compressed, the upper die drive punch 5 follows the upper die to continue to descend and pushes the concave module 6 to continue to slide to the left along the guide groove of the concave die guide block 7 and begin to shrink and form the steel pipe 1, while the spring box assembly 9 continues to be pulled and compressed by the concave module 6.

[0039] G. The upper mold stops descending, and the concave module 6 completes the necking and forming of the steel pipe 1.

[0040] H. The upper die begins to move upward along the outer guide post 2. The nitrogen spring 3 of the upper die begins to slowly relax and continues to hold the mandrel fixing block 12, mandrel 11 and steel pipe in their original positions. The upper die drive punch 5 moves upward with the upper die and disengages from the concave module 6. Under the action of the compressive force of the spring box assembly 9, the concave module 6 is pulled by the bolts of the spring box assembly 9 and begins to slide to the right along the guide groove of the concave die guide block 7 and disengage from the steel pipe after the necking and forming.

[0041] Working Principle: To improve heat dissipation efficiency, the DC axial fan 3 is strategically mounted on the bracket 2 and aligned with the housing 14. This arrangement ensures that airflow can directly reach the main heat sources, such as the sides and tail of the drive assembly 5 and the tail of the magnetic generator 6. Corresponding heat dissipation holes 4 are provided at the above locations, forming an effective heat dissipation channel. When the cooling fan operates, it draws in external cool air and exhausts hot air through the heat dissipation holes, quickly transferring heat from inside the equipment to the outside, preventing overheating and ensuring stable operation over a long period. In addition, an isolation cover 61 is provided on the top of the magnetic generator, which not only acts as a physical barrier but also helps guide airflow, making heat dissipation more uniform and effective.

[0042] The noise reduction component 7 consists of a noise reduction channel 71 and sound-absorbing cotton 72. The sound-absorbing cotton is tightly fitted to the inner wall of the noise reduction channel and installed along the length of the housing 1. This directional design guides noise along a specific path instead of spreading outwards, reducing its impact on the external environment. The sound-absorbing cotton 72, as a highly efficient sound-absorbing material, absorbs and reduces sound waves generated during equipment operation, especially mid-to-high frequency noise. By minimizing sound reflection, the noise reduction component 7 achieves better noise reduction, providing a quiet operating environment.

[0043] The side wall of the housing 1 is equipped with a warning light strip 11, a sensor 12, and a controller 13. The sensor 12 includes a temperature sensor, a current sensor, and a voltage sensor, which are respectively connected to the housing 14 and the drive assembly 5, for real-time monitoring of the internal operating status of the equipment, such as key parameters like temperature, current, and voltage. The data collected by the sensor 12 is transmitted to the controller 13, which is fixed in a controller mounting hole on the side wall of the housing and electrically connected to the sensors, warning light strip, and drive assembly. The controller 13 adjusts the operating mode or intensity of the drive assembly 5 to achieve intelligent control, optimizing treatment effects and ensuring safe and stable operation of the equipment. When the sensor 12 detects abnormal conditions such as overheating or excessive current, the warning light strip 11 illuminates with a specific color to alert the user to potential risks, allowing for timely measures to avoid these risks and improving the user's safety awareness.

[0044] The preferred embodiments of the present invention have been described in detail above. However, the present invention is not limited to the specific details of the above embodiments. Within the scope of the technical concept of the present invention, various equivalent transformations can be made to the technical solutions of the present invention, and all such equivalent transformations fall within the protection scope of the present invention.

Claims

1. A punch press die for necking down a steel tube, characterized by: The utility model provides a steel pipe straightening device, including upper die seat (4), upper die driving punch (5), lower die seat (10), outer guide column (2), core rod (11), core rod fixed block (12), female die module (6) and spring box assembly (9), upper die driving punch (5) is fixed on upper die seat (4), upper die seat (4) is connected lower die seat (10) through outer guide column (2), core rod fixed block (12) is installed on lower die seat (10), and core rod is fixed through bolt in core rod fixed block (12), and core rod (11) is used for the steel pipe to be shaped, female die module (6) is slidably installed on lower die seat (10), and spring box assembly (9) is used for the reset of female die module (6), and spring box assembly (9) is installed on lower die seat (10) through bolt.

2. The press die for necking a steel pipe according to claim 1, characterized by: Upper die nitrogen gas spring (3) is further arranged on the upper die seat (4), the upper die nitrogen gas spring (3) is fixed on the bottom of the upper die seat (4) through the bolt, and the upper die nitrogen gas spring (3) is located directly above the core rod fixed block (12).

3. The press die for necking a steel pipe according to claim 2, characterized in that: The outer guide column (2) includes outer guide column (2) and inner guide column (16), the outer guide column (2) is located between the upper die seat (4) and the lower die seat (10), and the core rod fixed block (12) is slidably installed on the inner guide column (16).

4. The press die for necking a steel pipe according to claim 1, characterized by: The lower die seat (10) is further provided with a female die guide block (7), a lower die fixed plate (13), a limiting bolt (15) and a female die reset guide block (8), the female die module (6) is slidably installed on the female die guide block (7), the female die module (6) reset guide block is connected with the female die module (6) through the spring box assembly (9), one end of the spring box assembly (9) is connected with the threaded hole of the female die module (6) through bolt, the other end is on the female die reset guide block (8), the lower die fixed plate (13) is installed on the lower die seat (10), the limiting bolt (15) is installed on the lower die fixed plate (13) through thread, and the head of the limiting bolt (15) limits the upstroke height of the core rod fixed block (12).

5. The steel tube necking press die according to claim 1, characterized by: The upper die driving punch (5) is a trapezoidal structure, the female die module (6) is also a trapezoidal structure, and the upper die driving punch (5) is matched with the female die module (6).

6. The press die for necking a steel pipe according to claim 5, characterized in that: The core rod fixed block (12) and the lower die seat (10) are further provided with a spring (14), one end of the spring (14) is fixed inside the lower die seat (10), and the other end is in contact with the core rod fixed block (12).

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