Pulse discharge hot-pressing seal welding device and seal welding method for sheathing powder discharging pipe

Abstract

The invention discloses a pulse discharge hot-pressing seal welding device and a seal welding method for a sheath powder feeding pipe, and relates to the technical field of seal welding of sheath powder feeding pipes, the pulse discharge hot-pressing seal welding device comprises a servo hydraulic system, a pulse current seal welding system and a seal welding mold assembly, the pulse current seal welding system comprises a pulse direct current generator, a first electrode assembly and a second electrode assembly, wherein the first electrode assembly and the second electrode assembly are connected with the pulse direct current generator. The seal welding mold assembly comprises a movable mold assembly and a static mold assembly. The servo hydraulic system is connected with the first electrode assembly, and the first electrode assembly is connected with the movable mold assembly; the second electrode assembly is connected with the static die assembly. The pulse current can cause local melting at a weldment interface, the current penetrates through a welding seam gap and even breaks down residual gas, the limitation that in the traditional technology, holes are filled depending on material plastic deformation is eliminated, metallurgical bonding is directly formed on the welding seam interface, and the gap defect is avoided. Reliable pressure is applied in a closed loop mode through the servo hydraulic system, and therefore reliable seal welding of the powder discharging pipe is achieved.

Description

Technical Field

[0001] The invention relates to the technical field of sealing welding of a jacketed lower powder hose, and in particular to a pulse discharge hot-pressing sealing welding device and a sealing welding method for a jacketed lower powder hose. Background Art

[0002] Hot isostatic pressing (HIP) combines powder metallurgy with die technology. Under the combined loads of high temperature and pressure, HIP works in conjunction with the die's forming action to densify powder materials, creating high-performance components with controllable shapes and structures. This technology is highly suitable for forming difficult-to-machine materials and is widely used in aircraft and rocket engine components. It has become a hot research topic in industrialized countries around the world.

[0003] In the hot isostatic pressing (HIP) process for alloy powders, the sealing performance of the can is directly related to the final part quality. Existing techniques typically use a vacuum filling process to fill powder into a sealed can, followed by a sealing process. Current sealing techniques fall into two main categories: the first utilizes mechanical positioning and welding equipment in a vacuum environment for sealing, using a pre-placed plug to seal the lower powder hose. While this method offers advantages in terms of weld structural reliability, it also has significant limitations. First, the suspended nature of dust in a vacuum environment can easily cause the optical positioning system of the welding equipment to fail, affecting the precise positioning of the weld. Second, the operating space of traditional welding equipment is not compatible with the dusty environment, resulting in high operational complexity and the risk of weld leaks. The second sealing method mechanically flattens a specific area of the lower powder hose, then uses localized heating and pressure to gradually heal any remaining gaps in the pipe's inner wall under thermodynamic conditions. While this method simplifies the process, it also suffers from significant technical drawbacks: the presence of an oxide film and adherent powder on the pipe's inner wall can interfere with the healing process, leaving microscopic pores in the weld and reducing seal reliability.

[0004] The commonality of these technical deficiencies is that insufficient weld seal reliability can lead to abnormal oxygen exchange inside and outside the sheath, ultimately causing mechanical degradation and even scrapping of the component. The existing technology has yet to offer a systematic technical solution that effectively addresses the conflict between vacuum dust environment interference, weld defects, and seal reliability. This is the core technical issue addressed by this invention. Summary of the Invention

[0005] The technical problem to be solved by the embodiments of the present invention is how to improve the reliability of the sealing welding of the powder tube under the sheath.

[0006] In order to solve the above problems, in the first aspect, an embodiment of the present invention proposes a pulse discharge hot pressing sealing device for wrapping a lower powder tube, comprising a servo hydraulic system, a pulse current sealing system and a sealing mold assembly, wherein the pulse current sealing system comprises a pulse DC generator and a first electrode assembly and a second electrode assembly connected to the pulse DC generator, and the sealing mold assembly comprises a movable mold assembly and a static mold assembly; the servo hydraulic system is connected to the first electrode assembly, and the first electrode assembly is connected to the movable mold assembly; the second electrode assembly is connected to the static mold assembly.

[0007] A further technical solution is that the servo hydraulic system includes a hydraulic cylinder, a hydraulic valve and a push plate; the hydraulic valve is connected to the hydraulic cylinder, the plunger of the hydraulic cylinder is connected to the push plate, and the push plate is connected to the first electrode assembly.

[0008] Its further technical solution is that it also includes a sealing and welding frame, which is provided with a first chamber for accommodating the hydraulic cylinder; the servo hydraulic system also includes a displacement sensor, multiple guide pillars and a guide sleeve; the displacement sensor is arranged on the plunger of the hydraulic cylinder; one end of the multiple guide pillars is connected to the push plate, and the other end of the multiple guide pillars passes through the side wall of the first chamber; the guide sleeve is arranged on the guide pillar and is located between the guide pillar and the side wall of the first chamber.

[0009] A further technical solution is that the pulse current sealing system also includes a first copper bar and a second copper bar, the pulse DC generator is connected to the first electrode assembly through the first copper bar, and the pulse DC generator is connected to the second electrode assembly through the second copper bar.

[0010] A further technical solution is that the first electrode assembly includes a first electrode seat, a first inner electrode rod, a first sealing flange, a first outer electrode cap and a first thermal insulation pressure plate; the first electrode seat is connected to the first copper bar; one end of the first electrode seat is connected to the first thermal insulation pressure plate, and the other end of the first electrode seat is sleeved on the outside of the first inner electrode rod; the first sealing flange is sleeved on the outside of the first inner electrode rod and connected to the first electrode seat; the first outer electrode cap is detachably connected to one end of the first inner electrode rod, and the first outer electrode cap is connected to the movable mold assembly; the first thermal insulation pressure plate is connected to the push plate;

[0011] The second electrode assembly includes a second electrode seat, a second inner electrode rod, a second sealing flange, a second outer electrode cap and a second thermal insulation pressure plate; the second electrode seat is connected to the second copper busbar; one end of the second electrode seat is connected to the second thermal insulation pressure plate, and the other end of the second electrode seat is sleeved on the outside of the second inner electrode rod, and the second sealing flange is sleeved on the outside of the second inner electrode rod and connected to the second electrode seat; the second outer electrode cap is detachably connected to one end of the second inner electrode rod, and the second outer electrode cap is connected to the static mold assembly; a pressure sensor is provided on one side of the second thermal insulation pressure plate, and the pressure sensor is connected to the sealing frame.

[0012] A further technical solution is that the first electrode assembly further includes a conductive ring connected to the first copper bar and slidably sleeved on the outer side of the first electrode seat, and the second electrode seat is directly connected to the second copper bar.

[0013] A further technical solution is that it further includes a circulating water cooling system, wherein the circulating water cooling system includes a first cooling pipeline and a second cooling pipeline, wherein a portion of the first cooling pipeline is disposed within the first inner electrode rod, and interfaces at both ends of the first cooling pipeline extend to the outside of the first electrode holder;

[0014] The second electrode assembly further includes a second cooling pipeline, a portion of which is disposed within the second inner electrode rod, and interfaces at both ends of the second cooling pipeline extend to the outside of the second electrode seat.

[0015] Its further technical solution is that the movable mold assembly and the static mold assembly both include a conductive mold body, an insulating plate and a limit plate, the extrusion side of the conductive mold body is protruding with an extrusion part, the insulating plates are provided on both sides of the extrusion part, the limiting plates are provided on the insulating plates, and the limiting plates protrude from the extrusion part; wherein, the conductive mold body of the movable mold assembly is connected to the second outer electrode cap; the conductive mold body of the static mold assembly is connected to the second outer electrode cap.

[0016] A further technical solution is that a first positioning portion is provided on the limiting plate of the movable mold assembly, and a second positioning portion is provided on the limiting plate of the static mold assembly, and the first positioning portion and the second positioning portion are engaged with each other; wherein, one of the first positioning portion and the second positioning portion is a positioning pin, and the other is a positioning hole.

[0017] In a second aspect, an embodiment of the present invention provides a pulse discharge hot-pressing sealing welding method for a sheathed lower powder hose, which is applied to the pulse discharge hot-pressing sealing welding device for a sheathed lower powder hose as described in the first aspect. The method comprises:

[0018] Place the lower powder hose between the movable mold assembly and the static mold assembly;

[0019] Pushing the first electrode assembly through the servo hydraulic system so that the movable mold assembly and the static mold assembly are closed and maintained in a pressure-locked state;

[0020] Controlling the pulse current sealing welding system to apply pulse current to the movable mold assembly and the static mold assembly through the first electrode assembly and the second electrode assembly to achieve hot pressing sealing welding of the pipe wall of the lower powder pipe;

[0021] After the pulse current of the pulse current sealing welding system is cut off, the servo hydraulic system is controlled to reset the first electrode assembly and the push plate.

[0022] Compared with the prior art, the embodiments of the present invention can achieve the following technical effects:

[0023] An embodiment of the present invention proposes a pulse discharge hot-pressing sealing device for wrapping a lower powder hose, comprising a servo hydraulic system, a pulse current sealing system, and a sealing mold assembly. The pulse current sealing system comprises a pulse DC generator and a first electrode assembly and a second electrode assembly connected to the pulse DC generator. The sealing mold assembly comprises a movable mold assembly and a static mold assembly. The servo hydraulic system is connected to the first electrode assembly, which is connected to the movable mold assembly. The second electrode assembly is connected to the static mold assembly. The pulse current of the pulse current sealing system can cause local melting at the weld interface. The current penetrates the weld gap and even breaks down residual gas, eliminating the limitation of traditional technology that relies on plastic deformation of the material to fill voids, allowing the weld interface to directly form a metallurgical bond and avoid void defects. At the same time, reliable pressure is applied through the closed loop of the servo hydraulic system, thereby achieving reliable sealing of the lower powder hose.

[0024] This invention proposes a pulse discharge hot-press welding device for wrapping the lower powder hose. By integrating a servo hydraulic system, a pulse current welding system, and a welding mold assembly, it achieves efficient and high-quality sealing of the lower powder hose. Its technical effectiveness stems from the following core design principles and their synergistic effects:

[0025] 1. Synergistic thermal effect of pulse discharge and thermal pressure

[0026] The device uses a servo-hydraulic system to drive the movable and static mold assemblies to close, causing the sealing mold to apply uniform pressure to the weldment, flattening the tube wall while maintaining stable contact. On this basis, a pulsed DC generator outputs a controllable pulse current to the first and second electrode assemblies, which is then transmitted through the mold to the weldment interface. The instantaneous high energy generated by the pulse discharge achieves precise welding through the following mechanisms:

[0027] Body heating and surface activation: The discharge shock wave generated by the pulse discharge and the high-speed flow of electrons and ions in opposite directions in the electric field can break down the initial oxide film at the weld interface to a certain extent, thereby purifying and activating it. In addition, because the pulse is instantaneous, intermittent, and occurs at a high frequency, the discharge heat generated in the non-contact parts of the interface and the Joule heat generated in the contact parts of the interface greatly promote the rapid interdiffusion of elements at the interface.

[0028] Breakdown of residual gas and bridging of porosity: The current penetrates the weld gap and even breaks down the residual gas, eliminating the limitation of traditional technology that relies on plastic deformation of the material to fill the void. It causes local melting at the weld interface, allowing the weld interface to directly form a metallurgical bond and avoid void defects.

[0029] 2. Structural design breaks through the limitations of traditional processes

[0030] Traditional hot press welding technology relies on external heat sources (such as resistance wire or laser) or vacuum environment to ensure welding quality, and requires additional solder or plugs, resulting in a complex process, high cost and susceptibility to dust interference. The improvements of the present invention are reflected in:

[0031] No need for a vacuum-sealed environment: The instantaneous high temperature and high pressure generated by pulse discharge can act directly on the welding interface, without relying on vacuum conditions to isolate the gas. This simplifies the equipment structure and reduces the complexity of operation, avoiding solder joint positioning problems caused by dust interference.

[0032] Eliminate the need for solder and plugs: Through current activation and interface metallurgy, the problem of solder point deviation caused by the addition of solder and plug positioning in traditional processes is avoided, significantly reducing material consumption and positioning adjustment costs;

[0033] Precise control of dynamic pressure and current: The servo hydraulic system can adjust the closing force and holding time in real time, while the pulsed DC generator optimizes welding heat input by adjusting the current frequency and amplitude, achieving adaptive welding of pipes of different materials and improving process versatility and reliability.

[0034] 3. Significant improvement in overall performance

[0035] Through the above technical solution, this device achieves the following technical effects:

[0036] High-quality metallurgical connection: The weld interface is completely fused, without pores, slag inclusions or unfused defects, and the mechanical properties of the joint (such as tensile strength and fatigue life) are significantly better than those of traditional processes;

[0037] Efficient and stable production: The instantaneous heating characteristics of pulse discharge shorten the welding time and eliminate the need for vacuum system maintenance and solder pretreatment, significantly improving overall production efficiency.

[0038] In summary, the present invention breaks through the heat source limitations and process defects of traditional sealing technology through the synergistic effect of pulse discharge and hot pressing, and achieves comprehensive improvement in welding quality, cost control and production efficiency. It is particularly suitable for the field of powder tube sealing under sheathing, which has strict requirements on sealing and material integrity. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the invention and, together with the description, serve to explain the principles of the invention.

[0040] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0041] One or more embodiments are exemplarily illustrated by pictures in the corresponding drawings. These exemplifications do not constitute limitations on the embodiments. Elements with the same reference numerals in the drawings are represented as similar elements. Unless otherwise stated, the figures in the drawings do not constitute proportional limitations.

[0042] Figure 1 This is a schematic structural diagram of a pulse discharge hot-pressing sealing device for wrapping a lower powder hose, as proposed in an embodiment of the present invention;

[0043] Figure 2 This is a schematic diagram of an application scenario of a pulse discharge hot-pressing sealing device for wrapping a lower powder hose, as proposed in an embodiment of the present invention;

[0044] Figure 3 A schematic diagram of the control principle of a pulse discharge hot-pressing sealing device for wrapping a lower powder hose, proposed in an embodiment of the present invention;

[0045] Figure 4 A schematic diagram of the state changes of a sealing device during the execution of a pulse discharge hot-pressing sealing method for a sheathed lower powder hose proposed in an embodiment of the present invention;

[0046] Figure 5 This is the metallographic image of the interface of the powder tube after sealing using the traditional hot pressing welding technology;

[0047] Figure 6 This is a metallographic diagram of the interface of the lower powder hose after sealing using a pulse discharge hot-pressing sealing method for sheathing the lower powder hose proposed in an embodiment of the present invention.

[0048] Reference numerals

[0049] Pulse DC generator 101; guide column 102; servo hydraulic valve 103; displacement sensor 104; hydraulic cylinder 105; guide sleeve 106; push plate 107; interface 108; first electrode assembly 109; second electrode assembly 110; pressure sensor 111; sealing frame 112; first copper busbar 113; second copper busbar 114; sealing mold assembly 115; first thermal insulation plate 211; first electrode holder 212; first cooling pipeline 213; first inner electrode rod 214; first sealing flange 215; first outer electrode cap 216; conductive ring 217; connector 218; lower powder hose 219; vacuum jacket 220; second thermal insulation plate 221; second electrode holder 222; second cooling pipeline 223; second inner electrode rod 224; second sealing flange 225; second outer electrode cap 226; conductive mold body 301; insulating plate 302; positioning pin 303; limit plate 304. DETAILED DESCRIPTION

[0050] The following will be combined with the accompanying drawings of the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments. Similar component numbers in the drawings represent similar components. Obviously, the embodiments described below are only some of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0051] It will be understood that when used in this specification and the appended claims, the terms “comprises” and “comprising” indicate the presence of described features, integers, steps, operations, elements and / or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components and / or groups thereof.

[0052] It should also be understood that the terms used in this description of the embodiments of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the embodiments of the present invention. As used in the description of the embodiments of the present invention and the appended claims, the singular forms "a", "an", and "the" are intended to include the plural forms unless the context clearly indicates otherwise.

[0053] See also Figure 1-Figure 3 The embodiment of the present invention provides a pulse discharge hot-press welding device for encapsulating a lower powder hose. The device can effectively improve the reliability of the welding of the lower powder hose 219, which is connected to the vacuum jacket 220. To achieve the above technical objectives, the pulse discharge hot-press welding device for encapsulating the lower powder hose includes a servo hydraulic system, a pulse current welding system, and a welding mold assembly 115. The specific structure is described as follows:

[0054] The servo hydraulic system is used to provide the pressure required for sealing the lower powder pipe 219.

[0055] The pulse current sealing welding system includes a pulse DC generator 101 and a first electrode assembly 109 and a second electrode assembly 110 connected to the pulse DC generator 101, and is used to provide the pulse current required for sealing welding of the lower powder hose 219.

[0056] The sealing mold assembly 115 includes a movable mold assembly and a static mold assembly; the servo hydraulic system is connected to the first electrode assembly 109, and the first electrode assembly 109 is connected to the movable mold assembly; the second electrode assembly 110 is connected to the static mold assembly.

[0057] The movable mold assembly and the static mold assembly are used to squeeze the lower powder hose 219 and apply a pulse current to the lower powder hose 219 .

[0058] In practice, the pulse current of the pulsed current sealing system passes through the weldment interface and gaps, even breaking through residual gas within the pores, promoting rapid welding of the weld boundary. The servo hydraulic system ensures the accuracy of pressure and displacement through closed-loop control, avoiding sealing defects caused by overpressure or underpressure. The three separate systems (servo hydraulic system, pulsed current sealing system, and sealing mold assembly 115) work together to facilitate maintenance and functional expansion, adapting to the sealing requirements of different specifications of the lower powder hose 219.

[0059] The present invention proposes a pulse discharge hot-press welding device for wrapping a lower powder hose. By integrating a servo hydraulic system, a pulse current welding system, and a welding mold assembly 115, it achieves efficient, high-quality welding of the lower powder hose 219. Its technical effectiveness stems from the following core design principles and their synergistic effects:

[0060] 1. Synergistic thermal effect of pulse discharge and thermal pressure

[0061] The device uses a servo hydraulic system to drive the movable and static mold assemblies to close, causing the sealing mold to apply uniform pressure to the weldment, flattening the tube wall while maintaining stable contact. On this basis, the pulsed DC generator 101 outputs a controllable pulse current to the first electrode assembly 109 and the second electrode assembly 110, which is transmitted through the mold to the weldment interface. The instantaneous high energy generated by the pulse discharge achieves precise welding through the following mechanisms:

[0062] Body heating and surface activation: Due to the discharge shock wave generated by pulse discharge and the high-speed flow of electrons and ions in the opposite direction in the electric field, the initial oxide film at the weld interface can be broken down to a certain extent, so that it can be purified and activated; in addition, since the pulse is instantaneous, intermittent, and occurs at a high frequency, the discharge heat generated at the non-contact part of the interface and the Joule heat generated at the contact part of the interface greatly promote the rapid mutual diffusion of elements at the interface.

[0063] Breakdown of residual gas and bridging of porosity: The current penetrates the weld gap and even breaks down the residual gas, eliminating the limitation of traditional technology that relies on plastic deformation of the material to fill the void. It causes local melting at the weld interface, allowing the weld interface to directly form a metallurgical bond and avoid void defects.

[0064] 2. Structural design breaks through the limitations of traditional processes

[0065] Traditional hot press welding technology relies on external heat sources (such as resistance wire or laser) or vacuum environment to ensure welding quality, and requires additional solder or plugs, resulting in a complex process, high cost and susceptibility to dust interference. The improvements of the present invention are reflected in:

[0066] No need for a vacuum-sealed environment: The instantaneous high temperature and high pressure generated by pulse discharge can act directly on the welding interface, without relying on vacuum conditions to isolate the gas. This simplifies the equipment structure and reduces the complexity of operation, avoiding solder joint positioning problems caused by dust interference.

[0067] Eliminate the need for solder and plugs: Through current activation and interface metallurgy, the problem of solder point deviation caused by the addition of solder and plug positioning in traditional processes is avoided, significantly reducing material consumption and positioning adjustment costs;

[0068] Precise control of dynamic pressure and current: The servo hydraulic system can adjust the closing force and holding time in real time, while the pulsed DC generator 101 optimizes welding heat input by adjusting the current frequency and amplitude, achieving adaptive welding of pipes of different materials and improving process versatility and reliability.

[0069] 3. Significant improvement in overall performance

[0070] Through the above technical solution, this device achieves the following technical effects:

[0071] High-quality metallurgical connection: The weld interface is completely fused, without pores, slag inclusions or unfused defects, and the mechanical properties of the joint (such as tensile strength and fatigue life) are significantly better than those of traditional processes;

[0072] Efficient and stable production: The instantaneous heating characteristics of pulse discharge shorten the welding time and eliminate the need for vacuum system maintenance and solder pretreatment, significantly improving overall production efficiency.

[0073] In summary, the present invention breaks through the heat source limitations and process defects of traditional sealing technology through the synergistic effect of pulse discharge and hot pressing, and achieves comprehensive improvement in welding quality, cost control and production efficiency. It is particularly suitable for the field of powder tube sealing under sheathing, which has strict requirements on sealing and material integrity.

[0074] An embodiment of the present invention provides a pulse discharge hot-press welding device for wrapping a lower powder hose, comprising a servo hydraulic system, a pulse current welding system, and a welding mold assembly 115. The pulse current welding system comprises a pulse DC generator 101 and a first electrode assembly 109 and a second electrode assembly 110 connected to the pulse DC generator 101. The welding mold assembly 115 comprises a movable mold assembly and a static mold assembly. The servo hydraulic system is connected to the first electrode assembly 109, which is connected to the movable mold assembly. The second electrode assembly 110 is connected to the static mold assembly. The pulse current of the pulse current welding system causes local melting at the weld interface. The current penetrates the weld gap and even breaks down residual gas, eliminating the limitation of traditional technology that relies on plastic deformation of the material to fill voids. The weld interface directly forms a metallurgical bond, avoiding void defects. At the same time, reliable pressure is applied through the closed loop of the servo hydraulic system, thereby achieving reliable welding of the lower powder hose 219.

[0075] Furthermore, in some preferred embodiments, the servo hydraulic system includes a hydraulic cylinder 105, a hydraulic valve 103 and a push plate 107; the hydraulic valve 103 is connected to the hydraulic cylinder 105, the plunger of the hydraulic cylinder 105 is connected to the push plate 107 (for example, connected by fasteners and / or snap structures, which are not specifically limited in the present invention), and the push plate 107 is connected to the first electrode assembly 109 (for example, connected by fasteners and / or snap structures, which are not specifically limited in the present invention).

[0076] In a specific implementation, the hydraulic cylinder 105 may be specifically a double-headed plunger test hydraulic cylinder 105 , and the hydraulic valve 103 may be specifically a servo hydraulic valve 103 .

[0077] The servo hydraulic system rapidly responds to pressure changes during the welding process by adjusting the opening of hydraulic valve 103, adapting to the welding parameters of different materials. The plunger thrust of hydraulic cylinder 105 acts directly on push plate 107, eliminating backlash errors associated with mechanical transmission and ensuring uniform and stable force applied to the electrode assembly.

[0078] Furthermore, the pulse discharge hot pressing sealing device for wrapping the lower powder hose further includes a sealing frame 112, which is provided with a first chamber for accommodating the hydraulic cylinder 105, a second chamber for accommodating the pulse DC generator 101, and a working platform for the sealing process; the servo hydraulic system further includes a displacement sensor 104, a plurality of guide pillars 102 (for example, four guide pillars 102, which are not specifically limited in the present invention) and a guide sleeve 106; the displacement sensor 104 is provided on the plunger ( For example, it is arranged at one end of the plunger away from the push plate 107, which is not specifically limited in the present invention); one end of each of the guide pillars 102 is connected to the push plate 107 (for example, connected by fasteners and / or a snap-fit structure, which is not specifically limited in the present invention), and the other end of each of the guide pillars 102 passes through the side wall of the first chamber; the guide sleeve 106 is sleeved on the guide pillar 102 and is located between the guide pillar 102 and the side wall of the first chamber, and the guide sleeve 106 can be further fixed to the side wall of the first chamber.

[0079] In specific implementation, the sealing frame 112 provides overall support to reduce the impact of equipment vibration on sealing accuracy; the cooperation between the guide column 102 and the guide sleeve 106 ensures that the push plate 107 moves in a straight line to avoid uneven force on the electrode assembly or misalignment of the mold closing due to offset; the displacement sensor 104 provides real-time feedback of the plunger displacement data and cooperates with the servo system to ensure closed-loop control of the sealing process and improve positioning accuracy; the cooperation design of the guide column 102 and the guide sleeve 106 can improve the smoothness of the movement of the guide column 102.

[0080] Furthermore, in some preferred embodiments, the pulse current sealing system also includes a first copper busbar 113 and a second copper busbar 114, the pulse DC generator 101 is connected to the first electrode assembly 109 through the first copper busbar 113, and the pulse DC generator 101 is connected to the second electrode assembly 110 through the second copper busbar 114.

[0081] In specific implementation, the high conductivity of the copper busbar can carry the instantaneous large current required for pulse discharge, reducing energy loss caused by excessive resistance; the copper busbar serves as a standardized interface, facilitating the replacement or upgrade of electrode components and adapting to different sealing and welding process requirements.

[0082] Furthermore, in some preferred embodiments, the first electrode assembly 109 includes a first electrode holder 212, a first inner electrode rod 214, a first sealing flange 215, a first outer electrode cap 216, and a first heat-insulating pressure plate 211; the first electrode holder 212 is connected to the first copper bus 113; one end of the first electrode holder 212 is connected to the first heat-insulating pressure plate 211 (for example, by a fastener and / or a snap-fit structure, which is not specifically limited in the present invention), and the other end of the first electrode holder 212 is sleeved on the outer surface of the first inner electrode rod 214. On the other side, the first sealing flange 215 is sleeved on the outer side of the first inner electrode rod 214 and connected to the first electrode holder 212 (for example, connected by fasteners and / or a snap-fit structure, which is not specifically limited in the present invention); the first outer electrode cap 216 is detachably connected to one end of the first inner electrode rod 214 (for example, detachably connected by fasteners and / or a snap-fit structure, which is not specifically limited in the present invention); the first thermal insulation pressure plate 211 is connected to the push plate 107 (for example, connected by fasteners and / or a snap-fit structure, which is not specifically limited in the present invention);

[0083] The second electrode assembly 110 includes a second electrode seat 222, a second inner electrode rod 224, a second sealing flange 225, a second outer electrode cap 226 and a second thermal insulation pressure plate 221; the second electrode seat 222 is connected to the second copper bus 114; one end of the second electrode seat 222 is connected to the second thermal insulation pressure plate 221 (for example, by fasteners and / or snap-on structures, which are not specifically limited in the present invention), the other end of the second electrode seat 222 is sleeved on the outside of the second inner electrode rod 224, and the second sealing flange 225 is sleeved on the outside of the second inner electrode rod 224 and is connected to the second copper bus 114. The second electrode seat 222 is connected (for example, connected by fasteners and / or snap structures, which is not specifically limited in the present invention); the second outer electrode cap 226 is detachably connected to one end of the second inner electrode rod 224 (for example, detachably connected by fasteners and / or snap structures, which is not specifically limited in the present invention), and the second outer electrode cap 226 is connected to the static mold assembly; a pressure sensor 111 is provided on one side of the second thermal insulation pressure plate 221, and the pressure sensor 111 is connected to the sealing frame 112 (for example, connected by fasteners and / or snap structures, which is not specifically limited in the present invention).

[0084] In a specific implementation, the first outer electrode cap 216 and the second outer electrode cap 226 are both provided with a connector 218; the connector 218 on the first outer electrode cap 216 is used to connect the movable mold assembly; the connector 218 on the second outer electrode cap 226 is used to connect the static mold assembly; the sealing flange is fixed to the outside of the inner electrode rod to prevent impurities from penetrating into the interior of the electrode assembly during the sealing process, thereby extending the life of the components; the thermal insulation pressure plate isolates the electrode assembly from the high-temperature area, protecting the push plate 107 and other components from thermal damage; the outer electrode cap is detachable for easy replacement, reducing downtime for maintenance; the pressure sensor 111 of the second electrode assembly 110 monitors the sealing pressure in real time to ensure that the pressure parameters meet the process requirements and avoid sealing defects caused by overvoltage or undervoltage; the sleeve structure of the electrode holder and the inner electrode rod ensures mechanical strength and reduces the volume of the electrode assembly.

[0085] Furthermore, in some preferred embodiments, the first electrode assembly 109 further includes a conductive ring 217 , which is connected to the first copper bus 113 , and the conductive ring 217 is slidably mounted on the outer side of the first electrode seat 212 .

[0086] In practice, the conductive ring 217 is slidably mounted on the outside of the electrode holder, ensuring continuous and stable current transmission during the movement of the first electrode holder 212 and preventing poor contact. The direct connection between the conductive ring 217 and the first copper busbar 113 improves current transmission efficiency. The adjustability of the conductive ring 217 allows for adaptability to varying lengths of electrode holder travel. The conductive ring 217 is made of a highly conductive material and is in sliding contact with the outside of the first electrode holder 212 via elastic compression.

[0087] Furthermore, in some preferred embodiments, the pulse discharge hot pressing welding device for wrapping the lower powder hose also includes a circulating water cooling system, and the circulating water cooling system includes a first cooling pipeline 213 and a second cooling pipeline 223. A portion of the first cooling pipeline 213 is arranged in the first inner electrode rod 214, and the interfaces 108 at both ends of the first cooling pipeline 213 extend to the outside of the first electrode seat 212; the interfaces 108 at both ends of the first cooling pipeline 213 are respectively a coolant inlet and a coolant outlet.

[0088] A portion of the second cooling pipeline 223 is disposed in the second inner electrode rod 224 , and the interfaces 108 at both ends of the second cooling pipeline 223 extend to the outside of the second electrode seat 222 ; the interfaces 108 at both ends of the second cooling pipeline 223 are respectively a coolant inlet and a coolant outlet.

[0089] In a specific implementation, the first cooling pipe 213 directly contacts the high-temperature area of the first inner electrode rod 214, and the second cooling pipe 223 directly contacts the high-temperature area of the second inner electrode rod 224, which can quickly remove the heat generated by the pulse discharge and prevent the electrode from overheating and causing deformation or insulation failure; by circulating a cooling medium (such as water or oil) to reduce the temperature of the first inner electrode rod 214 and the second inner electrode rod 224, thermal fatigue damage can be effectively reduced; the embedded design of the first cooling pipe 213 and the second cooling pipe 223 avoids the complex layout of the external cooling system and simplifies the equipment structure; the interfaces 108 at both ends of the first cooling pipe 213 and the second cooling pipe 223 can be flexibly connected to different cooling systems to meet different sealing requirements.

[0090] Furthermore, in some preferred embodiments, the movable mold assembly and the static mold assembly both include a conductive mold body 301, an insulating plate 302 and a limit plate 304, the extrusion side of the conductive mold body 301 is protruding with an extrusion portion, the insulating plates 302 are provided on both sides of the extrusion portion, the limiting plates 304 are provided on the insulating plates 302, and the limiting plates 304 protrude from the extrusion portion; wherein, the conductive mold body 301 of the movable mold assembly is connected to the second outer electrode cap 226, for example, through a connector 218; the conductive mold body 301 of the static mold assembly is connected to the second outer electrode cap 226, for example, through a connector 218.

[0091] In specific implementation, the conductive mold body 301 ensures that the current is efficiently transmitted to the sealing area of the lower powder tube 219, thereby improving the hot pressing efficiency; the insulating plate 302 can avoid direct contact and conduction between the conductive mold bodies 301; the limiting plate 304 protrudes from the extrusion part, limiting the displacement of the lower powder tube 219 during the sealing process, thereby ensuring the uniformity of the sealing surface.

[0092] Furthermore, in some preferred embodiments, a first positioning portion is provided on the limiting plate 304 of the movable mold assembly, and a second positioning portion is provided on the limiting plate 304 of the static mold assembly, and the first positioning portion and the second positioning portion are interlocked with each other; wherein, one of the first positioning portion and the second positioning portion is a positioning pin 303, and the other is a positioning hole.

[0093] In specific implementation, the cooperation between the positioning pin 303 and the positioning hole ensures the precise alignment of the movable mold assembly and the static mold assembly when they are closed, avoiding uneven sealing surfaces due to misalignment. At the same time, it reduces the friction resistance when the mold is closed and extends the life of the mold. The interlocking design of the first positioning part and the second positioning part can achieve rapid reset, avoiding time waste and error accumulation due to manual adjustment.

[0094] In the embodiment of the present invention, the generation of pulse current is mainly provided by the pulse DC generator 101, and is transmitted to the first electrode assembly 109 and the second electrode assembly 110 through the first copper bus 113 and the second copper bus 114. When the servo hydraulic system provides driving force, the first electrode assembly 109 and the second electrode assembly 110 are connected through the sealing mold assembly 115 and the lower powder pipe 219, the entire pulse current circuit is closed and the sealing device works.

[0095] At the same time, the present invention is equipped with an electronic controller for information feedback, which is mainly used for processing feedback information from the displacement sensor 104, the pressure sensor 111 and the temperature sensor (the temperature sensor is provided in the sealing mold assembly 115 for measuring the sealing temperature) and controlling and implementing the sealing process of the device.

[0096] See also Figure 4 , and combined with Figure 1-Figure 3 The embodiment of the present invention provides a pulse discharge hot-pressing sealing welding method for a sheathed lower powder hose, characterized in that the method is applied to the pulse discharge hot-pressing sealing welding device for a sheathed lower powder hose as described in any of the above embodiments, and comprises:

[0097] S1, place the lower powder pipe 219 between the movable mold assembly and the static mold assembly.

[0098] In a specific implementation, the hydraulic cylinder 105 is driven by the hydraulic valve 103, which moves the push plate 107 and the first electrode assembly 109 to the set sealing operation space of the lower powder hose 219. The lower powder hose 219, the sealing mold assembly 115, the first electrode assembly 109, and the second electrode assembly 110 are positioned and assembled so that the lower powder hose 219 is located between the movable mold assembly and the static mold assembly.

[0099] The controller sets the sealing process, including the pressure applied and maintained, welding temperature, heating rate, and holding time, which are not specifically limited in the present invention. For example, in this embodiment, the lower powder tube 219 of the jacket is made of 304 stainless steel, with a sealing pressure of 50t, a welding temperature of 1000°C, a heating rate of 10°C / s, and a holding time of 3 minutes.

[0100] S2, pushing the first electrode assembly 109 through the servo hydraulic system, so that the movable mold assembly and the static mold assembly are closed and maintained in a pressure-locked state.

[0101] During the welding process, hydraulic cylinder 105 drives push plate 107 and first electrode assembly 109, causing the movable die assembly of the welding mold to move toward the fixed die assembly. Lower powder hose 219 contacts the movable and fixed die assemblies, respectively, and subsequently deforms under pressure. Finally, the movable and fixed die assemblies of the welding mold are completely closed, and the servo hydraulic system reaches and maintains a set pressure of 50t.

[0102] S3, controlling the pulse current sealing system to apply pulse current to the movable mold assembly and the static mold assembly through the first electrode assembly 109 and the second electrode assembly 110, so as to achieve hot pressing sealing of the tube wall of the lower powder tube 219.

[0103] In practice, pulsed DC generator 101 is activated, slowly applying a pulsed current. The temperature of lower powder tube 219 gradually rises, inducing localized discharges through micro-bumps in the non-contacting areas of the mating surfaces, breaking through the metal oxide film. The target temperature is then reached and maintained at 1000°C. Under a certain pressure, the mating surfaces gradually and completely adhere to each other, relying on creep of the parent metal. Simultaneously, at high temperatures, interdiffusion of elements occurs at the joint interface, ultimately forming a metallurgical bond.

[0104] S4, after cutting off the pulse current of the pulse current sealing welding system, controlling the servo hydraulic system to reset the first electrode assembly 109 and the push plate 107.

[0105] In a specific implementation, after the pulse current of the pulse current sealing welding system is cut off, the hydraulic cylinder 105 drives the push plate 107 and the first electrode assembly 109 to move in the opposite direction until they return to the initial position before welding. The first electrode assembly 109 and the push plate 107 are reset, and the sealing welding is completed.

[0106] The results of the verification experiment of this embodiment are as follows:

[0107] The pulse discharge hot press sealing welding device provided in this embodiment is subjected to a sealing welding verification experiment of the lower powder tube 219. The cross-sectional metallographic image of the lower powder tube 219 obtained after sealing welding is shown as follows: Figure 6 shown.

[0108] In order to demonstrate the significant benefits of the present invention, the lower powder tube 219 was sealed using conventional hot press welding technology. The lower powder tube 219 was also made of 304 stainless steel, heated to 1000°C, and subjected to a pressure of 50 tons. Figure 5 As shown. Obviously, after the sealing welding using this technology, there is a clear weld on the lower powder tube 219, and the welding interface has a metal oxide film layer and unclosed residual voids. However, when the pulse discharge hot pressure sealing welding device provided by the embodiment of the present invention is used to seal the sheathed lower powder tube 219, there is no obvious weld after welding, the metal oxide film is completely removed, and there are no unclosed residual voids or gaps. Obviously, the welding interface forms a metallurgical bond, which ensures the quality and comprehensive mechanical properties of the weldment material, thereby significantly improving the sealing reliability of the powder part.

[0109] In the above embodiments, the description of each embodiment has its own focus. For parts that are not described in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0110] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise" and the like to indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0111] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of the technical features being referred to. Thus, a feature identified as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, "plurality" means two or more, unless otherwise specifically defined.

[0112] In the present invention, unless otherwise expressly specified or limited, terms such as "mounted," "connected," "connect," and "fixed" should be understood broadly. For example, they may refer to connection, detachable connection, or integration; mechanical connection or electrical connection; direct connection or indirect connection through an intermediate medium; and internal communication between two components or interaction between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0113] In the present invention, unless otherwise expressly specified or limited, a first feature being "above" or "below" a second feature may include the first and second features being in direct contact, or may include the first and second features being in contact not directly but through another feature between them. Furthermore, a first feature being "above," "above," and "above" a second feature may include the first feature being directly above or obliquely above the second feature, or may simply mean that the first feature is higher in level than the second feature. A first feature being "below," "below," and "below" a second feature may include the first feature being directly below or obliquely below the second feature, or may simply mean that the first feature is lower in level than the second feature.

[0114] In the description of this specification, the reference terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" mean that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic expressions of the above terms should not be understood as necessarily referring to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art can combine and combine different embodiments or examples described in this specification.

[0115] Obviously, those skilled in the art may make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, to the extent such changes and modifications fall within the scope of the claims and their equivalents, the present invention is intended to encompass such changes and modifications.

[0116] The above description is a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in the present invention, and such modifications or substitutions are intended to be within the scope of protection of the present invention. Therefore, the scope of protection of the present invention shall be subject to the scope of protection of the claims.

Claims

1. A pulse discharge hot pressing sealing device for wrapping a lower powder pipe, characterized in that: It includes a servo hydraulic system, a pulse current sealing welding system and a sealing welding mold assembly. The pulse current sealing welding system includes a pulse DC generator and a first electrode assembly and a second electrode assembly connected to the pulse DC generator. The sealing welding mold assembly includes a movable mold assembly and a static mold assembly; the servo hydraulic system is connected to the first electrode assembly, the first electrode assembly is connected to the movable mold assembly; the second electrode assembly is connected to the static mold assembly.

2. The pulse discharge hot pressing sealing device for wrapping the lower powder hose according to claim 1 is characterized in that: The servo hydraulic system includes a hydraulic cylinder, a hydraulic valve and a push plate; the hydraulic valve is connected to the hydraulic cylinder, the plunger of the hydraulic cylinder is connected to the push plate, and the push plate is connected to the first electrode assembly.

3. The pulse discharge hot pressing sealing device for wrapping the lower powder hose according to claim 2 is characterized in that: It also includes a sealing and welding frame, which is provided with a first chamber for accommodating the hydraulic cylinder; the servo hydraulic system also includes a displacement sensor, a plurality of guide pillars and a guide sleeve; the displacement sensor is arranged on the plunger of the hydraulic cylinder; one end of the plurality of guide pillars is connected to the push plate, and the other end of the plurality of guide pillars passes through the side wall of the first chamber; the guide sleeve is arranged on the guide pillar and is located between the guide pillar and the side wall of the first chamber.

4. The pulse discharge hot pressing sealing device for wrapping the lower powder hose according to claim 3 is characterized in that: The pulse current sealing welding system also includes a first copper bar and a second copper bar. The pulse DC generator is connected to the first electrode assembly through the first copper bar, and the pulse DC generator is connected to the second electrode assembly through the second copper bar.

5. The pulse discharge hot pressing sealing device for wrapping the lower powder hose according to claim 4 is characterized in that: The first electrode assembly includes a first electrode holder, a first inner electrode rod, a first sealing flange, a first outer electrode cap, and a first thermal insulation pressure plate; the first electrode holder is connected to the first copper busbar; one end of the first electrode holder is connected to the first thermal insulation pressure plate, and the other end of the first electrode holder is sleeved on the outside of the first inner electrode rod; the first sealing flange is sleeved on the outside of the first inner electrode rod and connected to the first electrode holder; the first outer electrode cap is detachably connected to one end of the first inner electrode rod, and the first outer electrode cap is connected to the movable mold assembly; the first thermal insulation pressure plate is connected to the push plate; The second electrode assembly includes a second electrode seat, a second inner electrode rod, a second sealing flange, a second outer electrode cap and a second thermal insulation pressure plate; the second electrode seat is connected to the second copper busbar; one end of the second electrode seat is connected to the second thermal insulation pressure plate, and the other end of the second electrode seat is sleeved on the outside of the second inner electrode rod, and the second sealing flange is sleeved on the outside of the second inner electrode rod and connected to the second electrode seat; the second outer electrode cap is detachably connected to one end of the second inner electrode rod, and the second outer electrode cap is connected to the static mold assembly; a pressure sensor is provided on one side of the second thermal insulation pressure plate, and the pressure sensor is connected to the sealing frame.

6. The pulse discharge hot pressing sealing device for wrapping the lower powder hose according to claim 5, characterized in that: The first electrode assembly further includes a conductive ring, which is connected to the first copper busbar and is slidably sleeved on the outer side of the first electrode seat.

7. The pulse discharge hot pressing sealing device for wrapping the lower powder hose according to claim 5, characterized in that: The device further includes a circulating water cooling system, the circulating water cooling system including a first cooling pipeline and a second cooling pipeline, a portion of the first cooling pipeline is disposed within the first inner electrode rod, and interfaces at both ends of the first cooling pipeline extend to the outside of the first electrode holder; The second electrode assembly further includes a second cooling pipeline, a portion of which is disposed within the second inner electrode rod, and interfaces at both ends of the second cooling pipeline extend to the outside of the second electrode seat.

8. The pulse discharge hot pressing sealing device for wrapping the lower powder hose according to claim 5, characterized in that: The movable mold assembly and the static mold assembly both include a conductive mold body, an insulating plate and a limit plate. The extrusion side of the conductive mold body is protruded with an extrusion portion, the insulating plates are provided on both sides of the extrusion portion, the limit plates are provided on the insulating plates, and the limit plates protrude from the extrusion portion; wherein the conductive mold body of the movable mold assembly is connected to the second outer electrode cap; the conductive mold body of the static mold assembly is connected to the second outer electrode cap.

9. The pulse discharge hot pressing sealing device for wrapping the lower powder hose according to claim 8, characterized in that: A first positioning portion is provided on the limiting plate of the movable mold assembly, and a second positioning portion is provided on the limiting plate of the static mold assembly, and the first positioning portion and the second positioning portion are engaged with each other; wherein, one of the first positioning portion and the second positioning portion is a positioning pin, and the other is a positioning hole.

10. A pulse discharge hot pressing welding method for wrapping a lower powder pipe, characterized in that: The pulse discharge hot pressing sealing device for wrapping a lower powder hose according to any one of claims 1 to 9, wherein the method comprises: Place the lower powder hose between the movable mold assembly and the static mold assembly; Pushing the first electrode assembly through the servo hydraulic system so that the movable mold assembly and the static mold assembly are closed and maintained in a pressure-locked state; Controlling the pulse current sealing welding system to apply pulse current to the movable mold assembly and the static mold assembly through the first electrode assembly and the second electrode assembly to achieve hot pressing sealing welding of the pipe wall of the lower powder pipe; After the pulse current of the pulse current sealing welding system is cut off, the servo hydraulic system is controlled to reset the first electrode assembly and the push plate.

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