Pulse current auxiliary electromagnetic welding device

Abstract

The utility model discloses a pulse current auxiliary electromagnetic welding device, which belongs to the field of electromagnetic pulse welding, and comprises an electromagnetic welding unit and a pulse current generating unit, the electromagnetic welding unit comprises a discharge component for generating a strong magnetic field, an inner rod and an outer pipe; the outer pipe and the inner rod which serve as the electromagnetic welding device also serve as a discharge switch of a pulse current generation assembly in the pulse current generation unit, when the electromagnetic welding unit discharges, the outer pipe deforms at a high speed to collide with the inner rod under the action of electromagnetic repulsive force, and when collision occurs, the pulse current generation assembly discharges to generate pulse current; under the action of pulse current, on one hand, welding interface grains can be refined, and the mechanical property of a welding joint is enhanced; meanwhile, cracks and holes in a welding interface can be fused, and partial residual stress in the joint can be eliminated; and on the other hand, the plasticity of the electromagnetic welding joint can be improved, and the defects such as cracks caused by excessive plastic deformation of the outer pipe are prevented.

Description

Technical Field

[0001] The utility model belongs to the technical field of electromagnetic pulse welding, and particularly relates to a pulse current assisted electromagnetic welding device. Background Art

[0002] Electromagnetic pulse welding technology started in the 1970s and is a relatively new welding process developed on the basis of electromagnetic forming technology. Electromagnetic pulse welding converts the electrical energy stored in the electromagnetic forming equipment into the kinetic energy of metal materials through a discharge circuit, and realizes the metallurgical bonding between dissimilar metal materials through the high-speed collision of two materials. Compared with traditional fusion welding, electromagnetic pulse welding technology is a solid-phase welding technology. Under the action of high-intensity pulsed electromagnetic force, due to the existence of different metal element concentration gradients, the interface materials will undergo plastic deformation and local melting under high pressure and high temperature environments, and the metal atoms in the body will diffuse with each other, realizing the metallurgical bonding between dissimilar metals; at the same time, since there is no obvious weld seam generated, the defects and potential hazards in the heat affected zone can be avoided. Due to the many advantages of electromagnetic pulse welding technology compared with fusion welding, it has been widely used in the welding of the same / dissimilar metals such as aluminum alloy, magnesium alloy and titanium alloy.

[0003] However, during the welding process of the existing electromagnetic pulse welding device, when the collision speed between the outer tube and the inner rod is relatively large, there will be defects such as cracks and pores at the welding joint interface; at the same time, due to the large plastic deformation of the outer tube, for metals with poor plasticity such as aluminum, magnesium and titanium, microcracks may occur at the position with the largest plastic deformation, and the tensile test result is fracture at the position with the largest necking, thereby reducing the bearing capacity of the joint; in addition, due to the high-speed collision between the outer tube and the inner rod, the outer tube and the inner rod will generate large residual stresses due to severe plastic deformation. Usually, the outer tube has residual tensile stress and the inner rod has residual compressive stress. Due to the existence of residual stresses, the mechanical properties and fatigue properties of the welding joint will be affected.

[0004] It can be seen that when welding with the existing electromagnetic pulse welding device, it is easy to generate large residual stress and microcrack problems, resulting in poor bearing capacity of the joint. Summary of the Utility Model

[0005] The utility model provides a pulse current assisted electromagnetic welding device to solve the technical problem that when welding with the existing electromagnetic pulse welding device, it is easy to generate large residual stress and microcrack problems, resulting in poor bearing capacity of the joint.

[0006] In order to achieve the above purpose, the utility model adopts the following technical content:

[0007] A pulse current assisted electromagnetic welding device includes a pulse current generating unit and an electromagnetic welding unit;

[0008] The electromagnetic welding unit includes a discharge component, an inner rod, and an outer tube;

[0009] The discharge component is used to generate a strong magnetic field, thereby generating an electromagnetic repulsive force on the surface of the outer tube. The inner rod and the outer tube can collide under the action of the electromagnetic repulsive force to complete electromagnetic welding;

[0010] The pulsed current generating unit includes a pulsed current generating component. The pulsed current generating component is used to emit a pulsed current when the inner rod and the outer tube collide, so that the welding surface of the inner rod and the outer tube is repaired and improved under the action of the pulsed current.

[0011] Further, the discharge component includes a magnetic field coil, a second pulse capacitor bank, a discharge switch, and a second charger;

[0012] The magnetic field coil is connected in series with the second pulse capacitor bank to both ends of the second charger;

[0013] The discharge switch is arranged on the discharge loop formed by the magnetic field coil and the second pulse capacitor bank.

[0014] Further, the second pulse capacitor bank is also connected to the ground.

[0015] Further, the pulsed current generating component includes a first pulse capacitor bank and a first charger; one end of the first pulse capacitor bank is respectively connected to one end of the first charger and the outer tube, and the other end is respectively connected to the other end of the first charger and the inner rod.

[0016] Further, one end of the first pulse capacitor bank is also connected to the ground.

[0017] Further, a magnetic field concentrating unit is further included. The magnetic field concentrating unit is used to concentrate the strong magnetic field generated by the discharge component, so that the inner rod and the outer tube can collide under the action of the concentrated electromagnetic repulsive force.

[0018] Further, the magnetic field concentrating unit adopts a magnetic field concentrator; the strong magnetic field generated by the discharge component is constrained to the central working area of the magnetic field concentrator through the magnetic field concentrator.

[0019] Further, the height of the magnetic field concentrator is the same as that of the discharge component.

[0020] Further, the inner rod is inserted at one end of the outer tube, and a gap is formed between the inner rod and the outer tube.

[0021] Further, the charging voltage adopted by the pulsed current generating component is less than the breakdown voltage of the gap between the inner rod and the outer tube.

[0022] Compared with the prior art, the utility model has the following beneficial effects:

[0023] The utility model provides a pulsed current assisted electromagnetic welding device. The electromagnetic welding device includes an electromagnetic welding unit and a pulsed current generating unit. The electromagnetic welding unit includes a discharge assembly for generating a strong magnetic field, an inner rod and an outer tube. The outer tube and the inner rod of the electromagnetic welding device also serve as the discharge switches of the pulsed current generating assembly in the pulsed current generating unit. When the electromagnetic welding unit discharges, under the action of electromagnetic repulsion, the outer tube deforms rapidly and collides with the inner rod. When the collision occurs, the pulsed current generating assembly discharges to generate a pulsed current. Under the action of the pulsed current, on the one hand, it can refine the grains at the welding interface, enhance the mechanical properties of the welded joint. At the same time, it can also fuse the cracks and holes at the welding interface and eliminate some of the residual stresses inside the joint. On the other hand, it can also improve the plasticity of the electromagnetic welded joint, prevent excessive plastic deformation of the outer tube, and generate defects such as cracks.

[0024] Preferably, in the utility model, the discharge assembly includes a magnetic field coil, a second pulsed capacitor bank, a discharge switch and a second charger. This design makes the generation of electromagnetic repulsion more controllable and efficient, providing a stable power source for electromagnetic welding.

[0025] Preferably, in the utility model, the second pulsed capacitor bank is connected to the ground, improving the safety and stability of the system. In case of an abnormal situation, it can quickly conduct the charge to the ground, reducing potential safety hazards.

[0026] Preferably, in the utility model, the pulsed current generating assembly includes a first pulsed capacitor bank and a first charger, making the generation of pulsed current more accurate and reliable, providing the necessary energy support for the repair and improvement of the welding surface.

[0027] Preferably, in the utility model, one end of the first pulsed capacitor bank is connected to the ground, further improving the safety and stability of the system. During the transmission of the pulsed current, it can effectively prevent charge accumulation and leakage, protecting the safety of the equipment and operators.

[0028] Preferably, in the utility model, a magnetic field concentrating unit is introduced into the device. By concentrating the strong magnetic field generated by the discharge assembly, the efficiency and accuracy of the collision between the inner rod and the outer tube are improved, which helps to reduce energy loss and improve the welding effect.

[0029] Further preferably, in the utility model, a magnetic field concentrator is used as the magnetic field concentrating unit. The strong magnetic field generated by the magnetic field coil is constrained to the central working area of the magnetic field concentrator through the magnetic field concentrator, further improving the precision and controllability of electromagnetic welding.

[0030] Preferably, in the present utility model, the inner rod is inserted at one end of the outer tube, and a gap is formed between the two, such a design helps to achieve effective collision and welding under the action of electromagnetic repulsion force.

[0031] Preferably, in the present utility model, it is required that the charging voltage adopted by the pulse current generating assembly is less than the withstand voltage of the gap between the inner rod and the outer tube, ensuring breakdown of the gap, thereby ensuring effective repair and improvement of the welding surface. Description of the Drawings

[0032] Figure 1 is a schematic structural diagram of a pulse current assisted electromagnetic welding device provided by an embodiment of the present utility model;

[0033] Figure 2 is a schematic structural diagram of another pulse current assisted electromagnetic welding device provided by an embodiment of the present utility model;

[0034] Figure 3 is a current distribution diagram in the joint when the pulse current assisted electromagnetic welding device provided by an embodiment of the present utility model is working.

[0035] Reference Signs:

[0036] 1 - magnetic field coil; 2 - second pulse capacitor bank; 3 - discharge switch; 4 - second charger; 5 - inner rod; 6 - outer tube; 7 - first pulse capacitor bank; 8 - first charger; 9 - ground; 10 - magnetic flux concentrator. Detailed Embodiments

[0037] In order to make the technical problems, technical solutions and beneficial effects solved by the present utility model clearer and more understandable, the following specific embodiments are used to further elaborate on the present utility model in detail. It should be understood that the specific embodiments described herein are only used to explain the present utility model and are not used to limit the present utility model.

[0038] To make the objectives, technical solutions and advantages of the embodiments of the present utility model clearer, the technical solutions in the embodiments of the present utility model will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present utility model. Obviously, the described embodiments are some, but not all, of the embodiments of the present utility model. Usually, the components of the embodiments of the present utility model described and shown in the drawings herein can be arranged and designed in various different configurations.

[0039] Therefore, the following detailed description of the embodiments of the present utility model provided in the drawings is not intended to limit the scope of the present utility model claimed, but merely represents selected embodiments of the present utility model. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present utility model without creative efforts fall within the scope of protection of the present utility model.

[0040] It should be noted that like reference numerals and letters refer to like items in the following figures. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0041] In the description of the embodiments of the present utility model, it should be noted that if terms such as "upper", "lower", "horizontal", "inner", etc. indicate the orientation or positional relationship based on the orientation or positional relationship shown in the figures, or the orientation or positional relationship in which the utility model product is usually placed during use, it is only for the convenience of describing the present utility model 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 construed as a limitation to the present utility model. In addition, terms such as "first", "second", etc. are only used for distinguishing descriptions and cannot be construed as indicating or implying relative importance.

[0042] In addition, if the term "horizontal" appears, it does not mean that the component is required to be absolutely horizontal, but it can be slightly inclined. For example, "horizontal" only means that its direction is more horizontal relative to "vertical", and does not mean that the structure must be completely horizontal, but it can be slightly inclined.

[0043] In the description of the embodiments of the present utility model, it should also be noted that unless otherwise clearly specified and limited, if terms such as "set", "installed", "connected", "connected" are understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present utility model can be understood according to specific situations.

[0044] The following further describes the present utility model in detail with reference to the figures:

[0045] Embodiment 1

[0046] Combined with what is mentioned in the background art, during the welding process of the existing electromagnetic pulse welding device, when the collision speed between the outer tube and the inner rod is relatively large, there will be defects such as cracks and pores at the welding joint interface; at the same time, due to the large plastic deformation of the outer tube, for metals with poor plasticity such as aluminum, magnesium, and titanium, microcracks may occur at the position with the largest plastic deformation, and the tensile test result is fracture at the position with the largest necking, thereby reducing the bearing capacity of the joint; in addition, due to the high-speed collision between the outer tube and the inner rod, large residual stresses will be generated in the outer tube and the inner rod due to severe plastic deformation. Usually, there is residual tensile stress on the outer tube and residual compressive stress on the inner rod. Due to the existence of residual stress, the mechanical properties and fatigue properties of the welding joint will be affected.

[0047] At present, there have been a large number of studies on the electro-pulse treatment of metal materials, and many experiments have confirmed that when metal materials are subjected to electro-pulse treatment, pure electroplasticity effects, Joule heating effects, etc. will occur; at the same time, some scholars have also shown through research that electro-pulses can replace traditional furnace heating for heat treatment of metal materials; therefore, the pulsed current treatment technology has incomparable advantages in improving the plasticity of metal materials, promoting recrystallization and recovery, grain refinement, and micro-crack repair. In addition, compared with traditional heat treatment, pulsed current treatment can provide a large amount of energy in a very short time, enabling metal materials to undergo recrystallization, phase transformation, etc. relatively quickly at low temperatures.

[0048] Therefore, this embodiment draws on the advantages of electro-pulse treatment, and the present utility model proposes a pulsed current-assisted electromagnetic welding device, which uses pulsed high current to improve the plasticity of the outer tube, avoid the generation of defects such as micro-cracks in the weld, and at the same time refine grains, eliminate residual stress in the joint part, and improve the mechanical properties of the joint.

[0049] As Figure 1 shown, this embodiment provides a pulsed current-assisted electromagnetic welding device, which includes two core units: a pulsed current generating unit and an electromagnetic welding unit, specifically as follows:

[0050] In this embodiment, the electromagnetic welding unit includes: a discharge assembly, an inner rod 5 (workpiece to be welded), and an outer tube 6.

[0051] Specific working principle: The discharge assembly, through the synergistic action of a precisely designed magnetic field coil 1 and a second pulsed capacitor bank 2, generates a strong electromagnetic repulsive force; this repulsive force drives the inner rod 5 and the outer tube 6 to collide quickly and accurately, thereby achieving electromagnetic welding.

[0052] In this embodiment, the inner rod 5 is cleverly inserted into one end of the outer tube 6, and a fine gap is reserved between the two to ensure effective collision under the action of electromagnetic repulsive force.

[0053] In this embodiment, the pulsed current generating unit is composed of a first pulsed capacitor bank 7 and a first charger 8.

[0054] Specific working principle: When the inner rod 5 and the outer tube 6 in the electromagnetic welding unit collide, the pulsed current generating unit responds immediately and releases a high-energy pulsed current through the first pulsed capacitor bank 7. This pulsed current directly acts on the welding surface, effectively repairing the possible tiny defects during the welding process and improving the overall quality of the welded joint.

[0055] Safety design: To enhance the system safety, one end of the first pulsed capacitor bank 7 is specially designed with a grounding connection to ensure that in case of an abnormality, the charge can be quickly introduced into the ground 9 to prevent charge accumulation from causing potential risks.

[0056] In this embodiment, considering the safety of the operation of the entire device, the safety performance of the discharge component is enhanced: The second pulse capacitor bank 2 is also provided with a ground connection, which is connected to the ground 9, further improving the electrical safety during the entire electromagnetic welding process.

[0057] This embodiment has the characteristics of efficient energy management: The discharge switch 3 can accurately control the energy release between the magnetic field coil 1 and the second pulse capacitor bank 2, ensuring that the generation of electromagnetic repulsion is both rapid and stable.

[0058] In this embodiment, in order to ensure breakdown of the gap, thus ensuring effective repair and improvement of the welding surface, the charging voltage adopted by the pulse current generating component is less than the breakdown voltage of the gap between the inner rod 5 and the outer tube 6.

[0059] Similarly, this embodiment has the characteristics of integration and automation: The entire device is highly integrated. By precisely controlling the startup and collaborative work of each component, an automated process from electromagnetic welding to pulse current repair is achieved, greatly improving production efficiency and welding quality.

[0060] This embodiment provides a pulse current assisted electromagnetic welding device, and the specific usage process is as follows:

[0061] As Figure 3 shown, the current distribution diagram in the joint when the pulse current assisted electromagnetic welding device works. Among them, i1 is the induced eddy current in the outer tube 6, and the direction is circumferential; i2 is the large current flowing through the outer tube 6, and the direction is circumferential; when the second pulse capacitor bank 2 of the electromagnetic welding device discharges to the magnetic field coil, under the action of electromagnetic repulsion, the outer tube 6 undergoes high-speed deformation and collides with the inner rod 5. When the breakdown voltage of the gap between the outer tube 6 and the inner rod 5 is less than the charging voltage of the first pulse capacitor bank 7, the gap between the outer tube 6 and the inner rod 5 breaks down, and the first pulse capacitor bank 7 discharges in a short circuit to generate a pulse large current; under the action of the pulse large current, on the one hand, the grains at the welding interface can be refined, enhancing the mechanical properties of the welded joint; at the same time, under the action of the thermal effect of the pulse current, the cracks and holes at the welding interface may fuse, and some of the residual stress inside the joint will be eliminated; on the other hand, the plasticity of the electromagnetic welding joint can be improved, preventing excessive plastic deformation of the outer tube and generating defects such as cracks.

[0062] This embodiment provides a pulse current assisted electromagnetic welding device. With its unique design concept and advanced technology implementation, it refines the grains at the welding interface, enhances the mechanical properties of the welded joint; eliminates some of the residual stress inside the joint; using this device can bring a new solution to the industrial welding field, significantly improving the reliability and economy of the welding process.

[0063] Embodiment 2

[0064] As Figure 2As shown, this embodiment provides another pulsed current-assisted electromagnetic welding device. Based on the same structure as Embodiment 1, on the basis of Embodiment 1, it has been optimized and improved. In this embodiment, a magnetic focusing unit for concentrating the electromagnetic repulsive force emitted by the discharge assembly is added. Specifically, a magnetic concentrator 10 can be used. The magnetic concentrator 10 can confine the strong magnetic field generated by the magnetic field coil 1 to the central working area of the magnetic concentrator and transfer the electromagnetic repulsive force to the outer tube 6, so that it collides with the inner rod 5. In this way, it helps to reduce energy loss and improve the welding effect. Among them, the height of the magnetic concentrator 10 is the same as that of the discharge assembly. Preferably, the height of the magnetic concentrator 10 is set the same as that of the magnetic field coil 1 of the discharge assembly.

[0065] In summary, the present utility model provides a pulsed current-assisted electromagnetic welding device, which has the following advantages compared with the existing electromagnetic welding devices:

[0066] This pulsed current-assisted electromagnetic welding device realizes double optimization during the welding process by integrating a pulsed current generating unit and an electromagnetic welding unit; the electromagnetic welding unit uses the electromagnetic repulsive force generated by the discharge assembly to prompt the inner rod and the outer tube to collide precisely, completing electromagnetic welding and ensuring the initial quality of the welding; at the same time, the pulsed current generating unit releases a pulsed current at the moment when the inner rod and the outer tube collide, instantaneously repairing and improving the welding surface, further enhancing the strength and reliability of the welded joint; in addition, the device also has characteristics such as efficient energy management, enhanced electrical safety, and optimized magnetic focusing. Through components such as a finely designed magnetic field coil, pulsed capacitor bank, discharge switch, and magnetic concentrator, it not only improves the welding efficiency but also ensures the safety of operation. This device has the advantages of high integration and high automation, providing an efficient, reliable, and economical solution for the industrial welding field.

[0067] The above embodiments are only one of the implementation manners capable of realizing the technical solution of the present utility model. The scope of protection required by the present utility model is not only limited by this embodiment, but also includes any changes, substitutions, and other implementation manners that are easily conceivable by those skilled in the art within the technical scope disclosed by the present utility model.

Claims

1. A pulsed current-assisted electromagnetic welding device, characterized in that, It includes a pulse current generating unit and an electromagnetic welding unit; The electromagnetic welding unit includes a discharge component, an inner rod (5) and an outer tube (6); The discharge component is used to generate a strong magnetic field, so as to generate an electromagnetic repulsive force on the surface of the outer tube (6), and the inner rod (5) and the outer tube (6) can collide under the action of the electromagnetic repulsive force to complete electromagnetic welding; The pulse current generating unit includes a pulse current generating component, and the pulse current generating component is used to emit a pulse current when the inner rod (5) and the outer tube (6) collide, so that the welding surfaces of the inner rod (5) and the outer tube (6) are repaired and improved under the action of the pulse current.

2. The pulse current-assisted electromagnetic welding device according to claim 1, characterized in that The discharge component includes a magnetic field coil (1), a second pulse capacitor bank (2), a discharge switch (3) and a second charger (4); The magnetic field coil (1) is serially connected to both ends of the second charger (4) in series with the second pulse capacitor bank (2); The discharge switch (3) is arranged on the discharge loop formed by the magnetic field coil (1) and the second pulse capacitor bank (2).

3. The pulsed current-assisted electromagnetic welding device according to claim 2, characterized in that, The second pulse capacitor bank (2) is also connected to the ground (9).

4. The pulsed current-assisted electromagnetic welding device according to claim 1, characterized in that, The pulse current generating component includes a first pulse capacitor bank (7) and a first charger (8); one end of the first pulse capacitor bank (7) is respectively connected to one end of the first charger (8) and the outer tube (6), and the other end is respectively connected to the other end of the first charger (8) and the inner rod (5).

5. An impulse current assisted electromagnetic welding device according to claim 4, wherein, One end of the first pulse capacitor bank (7) is also connected to the ground (9).

6. The pulse current-assisted electromagnetic welding device according to claim 1, characterized in that, It further includes a magnetic field concentrating unit, and the magnetic field concentrating unit is used to concentrate the strong magnetic field generated by the discharge component, so that the inner rod (5) and the outer tube (6) can collide under the action of the concentrated electromagnetic repulsive force.

7. The pulsed current-assisted electromagnetic welding device according to claim 6, characterized in that, The magnetic field concentrating unit adopts a magnetic field concentrator (10); the strong magnetic field generated by the discharge component is constrained to the central working area of the magnetic field concentrator (10) through the magnetic field concentrator (10).

8. An impulse current-assisted electromagnetic welding device according to claim 7, characterized in that, The magnetic field concentrator (10) has the same height as the discharge component.

9. The pulsed current-assisted electromagnetic welding device according to claim 1, wherein, The inner rod (5) is inserted at one end of the outer tube (6), and a gap is formed between the inner rod (5) and the outer tube (6).

10. The pulsed current-assisted electromagnetic welding device according to claim 9, characterized in that, The charging voltage adopted by the pulse current generating component is less than the breakdown voltage of the gap between the inner rod (5) and the outer tube (6).

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