A plug assembly and a pressure medium system

Abstract

The application discloses a plug assembly and a pressure medium system, which comprises a plug main body, the plug main body is provided with a plug medium hole, and the plug medium hole is used for passing in pressure medium; one end of the plug main body is provided with a cladding plugging hole which is in communication with the plug medium hole, the cladding plugging hole is used for being cladded on the outside of a pipe to be formed and is in interference fit with the pipe to be formed, one end of the cladding plugging hole is an open end, and the other end is provided with a sealing part which is used for being in sealing connection with the end face of the pipe to be formed. The cladding plugging hole is used for being cladded on the outside of the pipe to be formed and is in interference fit with the pipe to be formed. The plug main body is wrapped on the outer wall of the pipe to be formed, at this time, the structural design of the plug main body is no longer limited by the size of the inner diameter of the pipe to be formed, a more reasonable size and structure can be adopted, the strength of the plug main body is effectively improved, the plug main body can better bear the pressure generated in the bulging process, and the bulging process is ensured to be smoothly carried out.

Description

Technical Field

[0001] This application relates to the field of expansion system technology, and more specifically, to a plug assembly and pressure medium system. Background Technology

[0002] With increasingly stringent global energy conservation and emission reduction regulations, automotive lightweighting has become a core path to reduce energy consumption and emissions. Traditional metal structural components suffer from low material utilization, heavy weight, and insufficient strength and rigidity. To meet the lightweight requirements of metal tubing while maintaining its strength, an bulging technology has emerged. This technology involves heating the metal tubing and then introducing a pressure medium (such as high-pressure gas or high-pressure liquid) to cause it to expand and conform to a mold, forming a lightweight structural component with a hollow variable cross-section and complex curved surface. Compared to traditional stamped parts, these parts can reduce weight by approximately 35% while maintaining or improving structural strength, directly contributing to overall vehicle weight reduction and meeting the requirements for vehicle economy and driving range.

[0003] A hot gas forming system typically includes a heating system, a robotic gripping system, a pressure medium system, a mold press system, a hydraulic cylinder system, and a cooling system. The proper functioning of each system directly affects whether production can proceed normally and whether the produced parts meet quality standards. In the pressure medium system, maintaining the ultra-high pressure within the metal tubing requires extremely high sealing. If leakage occurs when the pressure medium is introduced, the pressure inside the tubing cannot be guaranteed, resulting in incomplete forming of the parts and the production of substandard components.

[0004] like Figure 1 and Figure 2 As shown, the traditional sealing method involves sealing the inner diameter of the metal pipe 02 with a plug 01. For metal pipes 02 with small diameters, the plug 01 cannot be made large due to the limitation of the inner diameter of the metal pipe 02. Therefore, for small-diameter metal pipes 02, the plug 01 is not strong enough and breaks frequently, failing to meet the requirements for mass production.

[0005] Therefore, how to ensure the strength of the plug assembly and prevent breakage is a problem that urgently needs to be solved by those skilled in the art. Utility Model Content

[0006] In view of this, the purpose of this application is to provide a plug assembly to ensure the strength of the plug assembly and prevent breakage;

[0007] Another objective of this application is to provide a pressure medium system having the above-described plug assembly.

[0008] To achieve the above objectives, this application provides the following technical solution:

[0009] A first aspect of this application provides a plug assembly, which includes a plug body and a plug medium hole for introducing a pressure medium.

[0010] One end of the plug body is provided with a covering and sealing hole that communicates with the plug medium hole. The covering and sealing hole is used to cover the outside of the pipe to be formed and is interference fit with the pipe to be formed. One end of the covering and sealing hole is an open end, and the other end is provided with a sealing part for sealing connection with the end face of the pipe to be formed.

[0011] In one possible implementation, the sealing portion includes at least two stepped portions.

[0012] In one possible implementation, the opening end of the sealing hole is a flared guide end, and the cross-sectional area of ​​the flared guide end gradually increases from the end near the sealing part to the end away from the sealing part.

[0013] In one possible implementation, the flared guide end has a rounded chamfer.

[0014] In one possible implementation, the plug body includes a mating section and a clearance section in the direction from the first end to the second end of the plug body. The mating section is used to have a clearance fit with the plug mating cavity of the mold, and the outer diameter of the clearance section is smaller than the outer diameter of the mating section.

[0015] The first end of the plug body is the end where the covering and sealing hole is located.

[0016] In one possible implementation, the plug assembly further includes an inner wall clamping block, which is fixed to the plug body and has a clamping block medium hole communicating with the plug medium hole.

[0017] The end of the inner wall clamping block is used to be inserted into the cavity of the pipe to be formed.

[0018] In one possible implementation, the plug body has an installation hole for installing the inner wall clamping block, the installation hole is arranged adjacent to the covering and sealing hole, and the diameter of the installation hole is smaller than the diameter of the covering and sealing hole.

[0019] In one possible implementation, the mounting hole includes a screw hole section and a guide hole section in the direction from one end near the end of the covering and sealing hole to the end away from the covering and sealing hole;

[0020] From one end near the sealing hole to the other end away from the sealing hole, the inner wall clamping block includes a guide insertion section, a threaded connection section, and a guide shaft section. The guide shaft section mates with the guide hole section, the threaded connection section mates with the threaded hole section, and the guide insertion section is inserted into the cavity of the pipe to be formed and is interference-fitted with the cavity of the pipe to be formed.

[0021] In one possible implementation, the nominal diameter of the screw hole section is larger than the diameter of the guide hole section;

[0022] And / or,

[0023] The outer diameter of the guide insertion section gradually decreases from one end of the threaded connection section to the end away from the threaded connection section.

[0024] Along the axial direction, a gasket is provided between the inner wall clamping block and the plug body.

[0025] The plug assembly provided in this application has a plug medium hole in its main body, through which a pressurized medium can be introduced into the pipe to be formed to complete the bulging process. One end of the plug main body has a covering and sealing hole, which is used to cover the outside of the pipe to be formed and has an interference fit with it. This application wraps the plug main body around the outer wall of the pipe to be formed. In this way, the structural design of the plug main body is no longer limited by the inner diameter of the pipe to be formed, allowing for more reasonable dimensions and structures, effectively improving the strength of the plug main body itself, enabling it to better withstand the pressure generated during the bulging process, and ensuring the smooth progress of the bulging process.

[0026] The contact area between the covered sealing hole and the outer wall of the pipe to be formed is larger than that of a plug insertion seal. This larger contact area creates a wider sealing zone, reducing the possibility of leakage at the seal. During the bulging process, even with fluctuations in the pressure medium, the larger contact area better maintains the sealing effect, ensuring pressure stability and guaranteeing uniform bulging of the pipe to be formed. One end of the covered sealing hole is open, and the other end has a sealing part for sealing connection with the end face of the pipe to be formed. By providing a sealing part, this application further improves the sealing effect between the plug assembly and the pipe to be formed through the sealing between the sealing part and the end face of the pipe to be formed.

[0027] A second aspect of this application provides a pressure medium system, comprising:

[0028] Piston cylinder;

[0029] A plug assembly, wherein the plug assembly is as described in any of the preceding claims, the plug body is fixed to the output pusher of the piston cylinder by a connector, and the connector is provided with a gas input hole communicating with the medium hole of the plug, and the gas input hole is provided with a gas connection for communicating with a gas passage.

[0030] The pressure medium system provided in this application has all the technical effects of the aforementioned plug assembly, which will not be elaborated further here. Attached Figure Description

[0031] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0032] Figure 1 This is an assembly view of a plug and pipe in an existing technology.

[0033] Figure 2 An assembly view of a plug and pipe with an alternative structure in the prior art;

[0034] Figure 3 This is a cross-sectional view of the plug assembly in operation according to an embodiment of this application;

[0035] Figure 4 for Figure 3 A magnified view of part A in the image;

[0036] Figure 5 This is a cross-sectional view of the plug assembly disclosed in an embodiment of this application;

[0037] Figure 6 for Figure 5 A magnified view of part B in the image;

[0038] Figure 7 This is a cross-sectional view of the assembly of the plug assembly and the pipe to be formed disclosed in the embodiments of this application;

[0039] Figure 8 for Figure 7 A magnified view of part C.

[0040] The meanings of the various reference numerals in the figure are as follows:

[0041] 01-Plug; 02-Metal pipe;

[0042] 100 - Upper model cavity insert;

[0043] 200-lower model cavity insert;

[0044] 300-Plug assembly; 310-Plug body; 311-Plug medium hole; 312-Matching section; 313-Void-avoiding section; 314-Encased sealing hole; 315-Flanged guide end; 316-Sealing part; 317-Screw hole section; 318-Guide hole section; 320-Inner wall clamping block; 321-Clamping block medium hole; 322-Guide insertion section; 330-Gasket;

[0045] 400 - Pipe to be formed; 401 - Outwardly arched curved surface;

[0046] 500-piston cylinder;

[0047] 600 - Connector; 601 - Gas inlet port. Detailed Implementation

[0048] This application discloses a plug assembly to ensure the strength of the plug assembly and prevent breakage;

[0049] This application also discloses a pressure medium system having the above-described plug assembly.

[0050] Hereinafter, embodiments will be described with reference to the accompanying drawings. Furthermore, the embodiments shown below do not limit the scope of the application as described in the claims. Additionally, the complete composition represented in the embodiments below is not limited to what is necessary as the solution to the application described in the claims. It should be noted that, for ease of description, only the parts relevant to the application are shown in the drawings. Unless otherwise specified, the embodiments and features described in this application can be combined with each other.

[0051] In the metal pipe bulging process, the sealing effect of the plug is crucial, directly affecting the smooth progress of the bulging process and the quality of the final product. The bulging process requires establishing and maintaining a certain pressure inside the metal pipe to achieve uniform expansion. A good plug seal prevents leakage of the pressure medium, ensuring that the bulging pressure remains stable throughout the process. If the plug seal is poor, leakage of the pressure medium will cause a pressure drop, resulting in uneven bulging of the metal pipe and failure to achieve the expected shape and dimensional accuracy.

[0052] Stable pressure is one of the key factors in ensuring the accuracy of bulging. Only under stable pressure can the pipe expand uniformly according to the predetermined mold cavity or design requirements, thereby obtaining a precise shape and size. Pressure fluctuations caused by poor sealing will result in inconsistent deformation of different parts of the pipe, leading to problems such as out-of-tolerance ovality and uneven wall thickness, affecting product quality and subsequent performance.

[0053] If the plug seal is ineffective and pressure leaks occur frequently, the machine needs to be shut down for inspection and repair, which will lead to production interruptions and reduced production efficiency. A reliable seal, on the other hand, ensures the expansion process is continuous and stable, reducing production delays caused by sealing problems and improving overall production efficiency.

[0054] For small-diameter metal pipes, inserting a plug into the pipe cavity to achieve a seal will result in a small plug diameter, leading to insufficient strength. This makes it prone to breakage during the piston-cylinder insertion process.

[0055] Based on this, this application discloses a plug assembly to ensure the strength of the plug assembly and prevent breakage.

[0056] like Figures 3-6 As shown, the plug assembly 300 disclosed in this application includes a plug body 310. The plug body 310 has a plug medium hole 311. The plug medium hole 311 is used to introduce a pressure medium. That is, the pressure medium can enter the pipe 400 to be formed through the plug medium hole 311 to realize the bulging process of the pipe 400 to be formed.

[0057] The forming mold includes an upper mold cavity insert 100 and a lower mold cavity insert 200, and the tube 400 to be formed is clamped between the upper mold cavity insert 100 and the lower mold cavity insert 200. When a pressure medium is introduced into the tube 400 to be formed, the tube wall of the tube 400 to be formed will deform according to the cavity structure of the forming mold under the pressure of the pressure medium, thus obtaining a tube with a corresponding structure.

[0058] One end of the plug body 310 has a covering and sealing hole 314 communicating with the plug medium hole 311. The covering and sealing hole 314 is used to cover the outside of the pipe 400 to be formed and is interference-fitted with the pipe 400 to be formed. The plug mating cavity at one end of the forming mold is used to insert the plug assembly 300, so that the plug body 310 can communicate with the end of the pipe 400 to be formed. This allows the pressure medium to be filled into the pipe 400 to be formed through the plug assembly 300, while preventing leakage of the pressure medium at the connection between the plug assembly 300 and the pipe 400 to be formed.

[0059] The plug assembly 300 disclosed in this application has a plug body 310 with a plug medium hole 311. A pressurized medium can be introduced into the pipe 400 to be formed through this plug medium hole 311 to complete the bulging process. One end of the plug body 310 has a covering and sealing hole 314, which covers the outside of the pipe 400 to be formed and is interference-fitted with it. This application wraps the plug body 310 around the outer wall of the pipe 400 to be formed. In this case, the structural design of the plug body 310 is no longer limited by the inner diameter of the pipe 400, allowing for more reasonable dimensions and structures, effectively improving the strength of the plug body 310, enabling it to better withstand the pressure generated during the bulging process and ensuring the smooth progress of the bulging process.

[0060] The contact area between the encapsulated sealing hole 314 and the outer wall of the pipe 400 to be formed is larger than that of a plug-type seal. This larger contact area creates a wider sealing zone, reducing the possibility of leakage at the seal. During the bulging process, even with fluctuations in the pressure medium, the larger contact area better maintains the sealing effect, ensuring pressure stability and guaranteeing uniform bulging of the pipe 400. One end of the encapsulated sealing hole 314 is open, and the other end has a sealing part for sealing connection with the end face of the pipe 400. Compared to the inner wall, the outer wall of the pipe 400 is easier to control in terms of processing precision and surface quality, and its surface condition is relatively stable. The encapsulated seal can better conform to the microscopic shape of the outer wall of the pipe 400, adapting to any minor unevenness on the surface of the pipe 400 and filling gaps caused by surface roughness or processing errors, thus achieving a more reliable seal.

[0061] One end of the sealing hole 314 is open, allowing it to be fitted over the outside of the tube 400 to be formed. The other end of the sealing hole 314 has a sealing part 316 for sealing connection with the end face of the tube 400. When the tube 400 is inserted into the bottom of the sealing hole 314, its end face abuts against the sealing part 316, pressing the sealing part 316 to achieve an end face seal. In this embodiment, the sealing effect between the plug assembly and the tube 400 is further improved by utilizing the seal between the sealing part 316 and the end face of the tube 400.

[0062] In one specific embodiment of this application, the sealing portion 316 may include at least two stepped portions. The end face of the tube 400 to be formed presses against the stepped portion. Under pressure, the edges of the stepped portion penetrate the end face of the tube 400 to be formed, forming a tight mechanical engagement with the tube 400. This engagement structure greatly increases the sealing contact area and effectively fills the tiny gap between the end face of the tube 400 to be formed and the plug body 310, preventing leakage of the pressure medium, ensuring pressure stability during the expansion process, further improving the reliability of the seal, helping to achieve uniform expansion of the tube 400 to be formed, and ensuring product quality.

[0063] The step portion inserting into the end face of the tube 400 to be formed creates multiple "anchor points" between them, greatly enhancing the connection strength between the plug body 310 and the tube 400. This ensures that even if the internal pressure of the tube 400 is high during the forming process, the plug body 310 is not easily detached from the tube 400, guaranteeing the smooth progress of the forming process and reducing the safety risks caused by the plug body 310 loosening or falling off.

[0064] The application and release of pressure during the bulging process may generate certain pressure shocks. The sealing structure achieved by inserting the stepped portion into the end face of the tube 400 to be formed can effectively disperse and resist such pressure shocks, prevent seal failure or loosening of the connection between the plug body 310 and the tube 400 to be formed due to pressure shocks, and ensure the stability of the entire bulging system.

[0065] like Figure 5 As shown in a specific embodiment of this application, the opening end of the sealing hole 314 is a flared guide end 315, and the cross-sectional area of ​​the flared guide end 315 gradually increases from the end near the sealing part 316 to the end away from the sealing part 316. The opening end of the sealing hole 314 is designed as a flared guide end 315, and the opening diameter of the flared guide end 315 is larger, which facilitates the insertion of the tube 400 to be formed. Even if the position of the tube 400 to be formed is offset, the plug body 310 can force the tube 400 to be formed to smoothly enter the sealing hole 314 along the guiding direction of the flared guide end 315.

[0066] like Figure 7 and Figure 8 As shown, the flared guide end 315 is further characterized by a rounded chamfer. The rounded chamfer acts as a guide, making it easier to align and insert the tube 400 to be formed into the sealing hole 314. The smooth transition of the rounded chamfer reduces friction and resistance between the tube 400 and the sealing hole 314, allowing the tube 400 to be formed to be pressed more easily and accurately into the appropriate position, improving assembly efficiency and reducing production delays caused by operational difficulties.

[0067] Under the forceful pushing action of the piston cylinder 500, the plug assembly 300 causes the tube 400 to be formed to deform, creating an outwardly arched arc surface 401 at the chamfered corner. This increases the contact area between the tube 400 and the sealing hole 314, making the fit tighter. Specifically, after the tube 400 deforms at the chamfered corner to form the outwardly arched arc surface 401, it can achieve a tighter fit with the chamfered corner of the opening end of the sealing hole 314. This tight fit effectively fills the tiny gaps between the tube 400 and the sealing hole 314, reducing the possibility of pressure medium leakage and significantly improving the sealing effect. Especially during the expansion process, a stable seal is crucial for maintaining internal pressure, helping to ensure uniform expansion of the tube 400 and improving product quality.

[0068] If the opening end of the sealing hole 314 lacks a rounded corner, stress concentration may occur at the sharp edge when the pipe 400 to be formed is pressed in, which could easily lead to localized damage or even breakage of the pipe 400. The rounded corner (i.e., chamfered edge) design ensures more uniform deformation of the pipe 400, allowing stress to be dispersed along the rounded corner, reducing the risk of excessive localized stress in the pipe 400, protecting its integrity, and extending its service life.

[0069] like Figure 5 As shown, from the first end to the second end of the plug body 310, the plug body 310 includes a mating section 312 and a clearance section 313. The first end of the plug body 310 is the end where the sealing hole 314 is provided. The mating section 312 is used for clearance fitting with the plug mating cavity of the mold, and the outer diameter of the clearance section 313 is smaller than the outer diameter of the mating section 312. The clearance section 313 is provided to prevent interference with other components of the mold.

[0070] like Figure 5 and Figure 6 As shown, the plug assembly disclosed in this embodiment may further include an inner wall clamping block 320. The inner wall clamping block 320 is fixed on the plug body 310, and the inner wall clamping block 320 has a clamping block medium hole 321 that communicates with the plug medium hole 311, so that the pressure medium can enter the pipe to be formed 400 through the plug medium hole 311 and the clamping block medium hole 321 to realize the bulging process of the pipe to be formed 400.

[0071] The end of the inner wall clamping block 320 is used to insert into the cavity of the pipe 400 to be formed, so as to seal the cavity of the pipe 400. The diameter of the inner wall clamping block 320 is larger than the inner diameter of the pipe 400 to be formed. When the piston cylinder forcibly pushes it into the cavity of the pipe 400 to be formed, the pipe 400 to be formed will expand outward, so that the outer surface of the pipe fits more closely with the sealing hole 314, thereby enhancing the sealing performance.

[0072] The sealing hole 314 is interference-fitted with the outer wall of the pipe to be formed 400, effectively filling the tiny gap between them and preventing fluid from entering from the outside. The inner wall clamping block 320 is interference-fitted with the inner wall of the pipe to be formed 400, further eliminating the leakage path of internal fluid. This double sealing effect is particularly crucial in industries with extremely high requirements for the sealing performance of pressure media, ensuring the safe and stable operation of the production process.

[0073] The double-sealing system tightly secures the pipe 400 to be formed from both the inner and outer sides, ensuring its precise positioning in space. This effectively improves the dimensional accuracy and consistency of the product, reducing the defect rate. Whether it's pressure impacts from inside the pipe or vibrations and impacts from the external environment, the robust structure formed by the double seal effectively disperses and resists these external forces, ensuring the stability of the pipe 400 under complex working conditions and guaranteeing the reliability and durability of the system.

[0074] The sealing hole 314 and the inner wall clamping block 320, through an interference fit, act as a protective structure for the pipe 400 to be formed, evenly distributing the pressure load from both the inside and outside, significantly improving the overall load-bearing capacity of the pipe 400. This allows the pipe 400 to withstand higher pressure and greater external forces, expanding its application range in high-strength application scenarios.

[0075] like Figure 6 As shown, the plug body 310 further includes a mounting hole for installing the inner wall clamping block 320. The mounting hole is arranged adjacent to the covering and sealing hole 314, that is, the mounting hole is located at the end of the covering and sealing hole 314 where the sealing part 316 is located. The diameter of the mounting hole is smaller than the diameter of the covering and sealing hole 314, so that the inner wall clamping block 320 can pass through the covering and sealing hole 314 and be installed in the mounting hole.

[0076] It should be noted that, in order to ensure that both the sealing hole 314 and the inner wall clamping block 320 can mate with the pipe 400 to be formed, the end of the inner wall clamping block 320 inserted into the pipe 400 needs to extend into the sealing hole 314. The length of the inner wall clamping block 320 extending into the sealing hole 314 can be understood as the length inserted into the pipe 400 to be formed. Those skilled in the art can set the length of the inner wall clamping block 320 extending into the sealing hole 314 based on sealing requirements.

[0077] The mounting hole includes a screw hole section 317 and a guide hole section 318 in the direction from one end near the covering and sealing hole 314 to the other end away from the covering and sealing hole 314.

[0078] Correspondingly, in the direction from the end near the sealing hole 314 to the end away from the sealing hole 314, the inner wall clamping block 320 includes a guide insertion section 322, a threaded connection section and a guide shaft section. The guide shaft section is engaged with the guide hole section 318, the threaded connection section is engaged with the threaded hole section 317, and the guide insertion section 322 is inserted into the cavity of the pipe 400 to be formed and is interference-fitted with the cavity of the pipe 400 to be formed.

[0079] To improve assembly efficiency, the inner wall clamping block 320 is not fully threaded axially; external threads are only present in the threaded connection section, while the rest remains unthreaded. During installation, after the guide shaft section is inserted into the guide hole section 318, the threaded connection section is aligned with the threaded hole section 317. Then, by rotating the inner wall clamping block 320, it can be gradually screwed into the mounting hole, thus assembling the inner wall clamping block 320. In this embodiment, external threads are only provided in certain areas, which shortens the axial length of the threaded connection section with external threads, thereby improving assembly efficiency.

[0080] The threaded fit provides clear guidance and positioning. When installing the inner wall clamping block 320, the engagement of the thread allows for precise guidance of the inner wall clamping block 320 to the corresponding position. Operators can accurately control the depth and position of the inner wall clamping block 320 based on the degree of thread engagement, ensuring a precise fit with the inner wall of the pipe and improving the accuracy and consistency of installation.

[0081] When the inner wall clamping block 320 needs to be replaced, it can be easily removed from the plug body 310 by rotating it in the reverse direction. Compared with other connection methods, the threaded connection disassembly process is simpler and faster, requiring no complicated tools or operations, which greatly shortens the equipment maintenance time.

[0082] In this embodiment, the nominal diameter of the screw hole section 317 is larger than the diameter of the guide hole section 318, so that when the inner wall clamping block 320 is installed, the guide shaft section of the inner wall clamping block 320 can easily pass through the screw hole section 317 of the mounting hole and be inserted into the guide hole section 318. With the cooperation of the guide shaft section and the guide hole section 318, the screw hole section 317 and the threaded connection section of the inner wall clamping block 320 can be easily aligned and fitted.

[0083] From one end of the threaded connection section to the end furthest from it, the outer diameter of the guide insertion section 322 gradually decreases. This reduced outer diameter structure of the guide insertion section 322 serves a guiding function; when the inner wall clamping block 320 is inserted into the pipe 400 to be formed, the outer surface of the guide insertion section 322 automatically guides it to accurately enter the pipe, reducing deviations and jamming during insertion. As the guide insertion section 322 is inserted into the cavity of the pipe 400, the contact area between the outer wall of the guide insertion section 322 and the inner wall of the pipe gradually increases, and the pressure increases uniformly accordingly. This gradual compression method creates a tighter contact, thereby improving sealing performance and reducing the possibility of leakage.

[0084] A gasket 330 is disposed between the inner wall clamping block 320 and the plug body 310 along the axial direction. The gasket 330 is located at the end of the inner wall clamping block 320 away from the guide insertion section 322. The gasket 330 can fill any tiny gaps that may exist between the inner wall clamping block 320 and the bottom wall of the mounting hole, providing an additional sealing effect. The gasket 330 can effectively prevent the pressure medium from leaking out from the gap between them, improving the overall sealing performance of the device.

[0085] like Figure 4 As shown in the embodiments, this application also discloses a pressure medium system, which includes a piston cylinder 500 and a plug assembly 300. The plug assembly 300 is the plug assembly 300 disclosed in the above embodiments.

[0086] The plug body 310 is fixed to the output push head of the piston cylinder 500 by the connector 600, and the connector 600 is provided with a gas input hole 601 that communicates with the plug medium hole 311. The gas input hole 601 is provided with a gas connection for communicating with the gas circuit.

[0087] The piston cylinder 500 is used to output the clamping force. The plug body 310 is fixed to the output push head through the connector 600, so that the piston cylinder 500 can press the plug assembly 300 onto the pipe to be formed 400, ensuring that the plug assembly 300 and the pipe to be formed 400 fit tightly together and ensure that there is a better sealing effect between them.

[0088] The gas source can be connected to a gas line connector to introduce a pressurized medium into the tube 400 to be formed, completing the tube expansion process. After the tube 400 is heated, it is fixed between the upper mold cavity insert 100 and the lower mold cavity insert 200. Then, high-pressure gas is introduced into the tube 400 through the plug assembly 300, causing it to expand and conform to the mold, forming a lightweight structural component with a hollow variable cross-section and complex curved surface. This application can both seal the tube 400 to be formed and ensure the strength of the plug assembly 300, meeting the requirements of mass production.

[0089] The pressure medium system disclosed in this application has the above-mentioned plug assembly 300, and therefore has all the technical effects of the plug assembly 300, which will not be repeated here.

[0090] As indicated in this application and claims, unless the context clearly indicates otherwise, the words "a," "an," "a," and / or "the" are not specifically singular and may include the plural. Generally, the terms "comprising" and "including" only indicate the inclusion of expressly identified steps and elements, which do not constitute an exclusive list, and the method or apparatus may also include other steps or elements. An element defined by the phrase "comprising an..." does not exclude the presence of other identical elements in the process, method, product, or apparatus that includes the element.

[0091] In the description of this application, unless otherwise expressly defined, terms such as "setup," "installation," and "connection" should be interpreted broadly, and those skilled in the art can reasonably determine the specific meaning of the above terms in this application in conjunction with the specific content of the technical solution.

[0092] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0093] This document uses specific examples to illustrate the principles and implementation methods of this application. The descriptions of the embodiments above are only for the purpose of helping to understand the method and core ideas of this application. It should be noted that those skilled in the art can make several improvements and modifications to this application without departing from the principles of this application, and these improvements and modifications also fall within the protection scope of the claims of this application.

Claims

1. A plug assembly, characterized in that, It includes a plug body (310), the plug body (310) having a plug medium hole (311) for introducing a pressure medium; One end of the plug body (310) is provided with a covering and sealing hole (314) communicating with the plug medium hole (311). The covering and sealing hole (314) is used to cover the outside of the pipe to be formed (400) and is interference fit with the pipe to be formed (400). One end of the covering and sealing hole (314) is an open end, and the other end is provided with a sealing part (316) for sealing connection with the end face of the pipe to be formed (400).

2. The plug assembly as described in claim 1, characterized in that, The sealing part (316) includes at least two stepped parts.

3. The plug assembly as described in claim 1, characterized in that, The opening end of the covering and sealing hole (314) is a flared guide end (315), and the cross-sectional area of ​​the flared guide end (315) gradually increases from the end near the sealing part (316) to the end away from the sealing part (316).

4. The plug assembly as described in claim 3, characterized in that, The flared guide end (315) has a rounded chamfer.

5. The plug assembly as described in claim 1, characterized in that, In the direction from the first end to the second end of the plug body (310), the plug body (310) includes a mating section (312) and a clearance section (313). The mating section (312) is used to have a clearance fit with the plug mating cavity of the mold. The outer diameter of the clearance section (313) is smaller than the outer diameter of the mating section (312). The first end of the plug body (310) is the end where the covering and sealing hole (314) is set.

6. The plug assembly as described in any one of claims 1-5, characterized in that, It also includes an inner wall clamping block (320), which is fixed on the plug body (310) and has a clamping block medium hole (321) that communicates with the plug medium hole (311). The end of the inner wall clamping block (320) is used to be inserted into the cavity of the tube to be formed (400).

7. The plug assembly as described in claim 6, characterized in that, The plug body (310) has an installation hole for installing the inner wall pressing block (320). The installation hole is arranged adjacent to the covering and sealing hole (314), and the diameter of the installation hole is smaller than the diameter of the covering and sealing hole (314).

8. The plug assembly as described in claim 7, characterized in that, The mounting hole includes a screw hole section (317) and a guide hole section (318) in the direction from one end near the covering and sealing hole (314) to the other end away from the covering and sealing hole (314). From one end near the covering and sealing hole (314) to the other end away from the covering and sealing hole (314), the inner wall pressing block (320) includes a guide insertion section (322), a threaded connection section and a guide shaft section. The guide shaft section is engaged with the guide hole section (318), the threaded connection section is engaged with the threaded hole section (317), and the guide insertion section (322) is inserted into the cavity of the tube to be formed (400) and is interference-fitted with the cavity of the tube to be formed (400).

9. The plug assembly as described in claim 8, characterized in that, The nominal diameter of the screw hole section (317) is larger than the diameter of the guide hole section (318); And / or, The outer diameter of the guide insertion section (322) gradually decreases from one end of the threaded connection section to the end away from the threaded connection section; Along the axial direction, a gasket (330) is provided between the inner wall pressing block (320) and the plug body (310).

10. A pressure medium system, characterized in that, include: Piston cylinder (500); A plug assembly (300) is a plug assembly (300) as described in any one of claims 1-9. The plug body (310) is fixed to the output push head of the piston cylinder (500) by a connector (600), and the connector (600) is provided with a gas input hole (601) communicating with the plug medium hole (311). The gas input hole (601) is provided with a gas connection for communicating with a gas path.

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