A brazing apparatus

Abstract

The application discloses a brazing welding device, which comprises a welding seat, a pressing part and an induction heater. The copper terminal is placed on the welding seat; the pressing part comprises a first pressing part for pressing the copper terminal on the welding seat and a second pressing part for pressing the aluminum wire on the copper terminal; the induction heater generates heat by induction current, only the brazing filler metal is melted in the brazing process, and the brazing filler metal, the aluminum wire and the copper terminal are fully diffused to form a firm metallurgical bond. The brazing welding device disclosed by the application adopts induction welding instead of the traditional flame welding mode, the whole welding process is free of open fire, the risk of fire is reduced, meanwhile, the vision or skin of the operator is not damaged; meanwhile, only the brazing filler metal is melted in the induction welding process, the first welding part and the second welding part both remain in a solid state, and the welding difficulty is reduced; the induction welding has the advantages of fast heating speed and high efficiency, can shorten the welding time, improves the production efficiency and reduces the production cost.

Description

Technical Field

[0001] This application relates to the field of transformer technology, and in particular to a brazing welding device. Background Technology

[0002] Aluminum wires have good electrical and thermal conductivity, and also have the advantages of low cost and light weight, making them widely used in coil manufacturing.

[0003] During the coil manufacturing process, aluminum wires are connected to copper terminals to meet electrical connection and installation requirements.

[0004] However, aluminum wires and copper terminals have different melting points and expansion coefficients, and the surface of aluminum wires is easily oxidized to form a high-melting-point oxide film, which makes the connection between aluminum wires and copper terminals very difficult. Utility Model Content

[0005] This application proposes a brazing device to reduce the difficulty of connecting aluminum wires and copper terminals.

[0006] To achieve the above objectives, this application provides a brazing welding apparatus, characterized in that it is used to connect a first welded component and a second welded component, wherein a brazing filler metal is sandwiched between the first welded component and the second welded component, and the melting point of the brazing filler metal is lower than that of the first welded component and the second welded component;

[0007] The brazing device includes a welding seat, a clamping component, and an induction heater;

[0008] The first weldment and the second weldment are stacked on the welding seat;

[0009] The clamping component includes a first clamping part and a second clamping part, wherein the first clamping part is used to clamp the first welded component, and the second clamping part is used to clamp the second welded component;

[0010] The induction coil of the induction heater is mounted on the welding base. The induction heater is used to melt the brazing filler metal, and the liquid brazing filler metal diffuses with the first and second welding parts to achieve a connection.

[0011] Optionally, in the above-mentioned brazing and welding apparatus, the welding seat includes a limiting member, which is used to limit the first welded part in a first direction and a second direction;

[0012] The first direction and the second direction are perpendicular to each other, and the first direction and the second direction are perpendicular to the pressing direction of the clamping member.

[0013] Optionally, in the above-mentioned brazing welding device, the limiting member is a limiting groove, and the limiting groove includes a first groove wall, a second groove wall, a third groove wall and a groove bottom;

[0014] The first groove wall and the second groove wall are used to limit the first welded part along the second direction;

[0015] The third groove wall is parallel to the pressing direction and perpendicular to the first direction. The third groove wall is used to limit the first welded part along the first direction.

[0016] The limiting groove also includes a first groove and a second groove, wherein the first groove and the second groove are connected.

[0017] The first slot is opposite to the bottom of the tank, and the first welded part is placed on the bottom of the tank through the first slot;

[0018] The second slot is opposite to the third slot wall, and the portion of the second welded part and the first welded part whose length along the first direction exceeds the limiting slot extends through the second slot.

[0019] Optionally, in the above-mentioned brazing and welding apparatus, both the first clamping part and the second clamping part are ceramic clamping blocks.

[0020] Optionally, in the above-described brazing welding apparatus, the first clamping part includes a first clamping groove that mates with the first welded part, and the second clamping part includes a second clamping groove that mates with the second welded part.

[0021] Optionally, in the above-mentioned brazing and welding apparatus, the clamping member further includes a driving member, which is used to drive the first clamping part and the second clamping part to move;

[0022] The first pressing part and the second pressing part share the driving member, or there are two driving members, and the two driving members are respectively connected to the first pressing part and the second pressing part.

[0023] Optionally, in the above-mentioned brazing and welding device, the driving component is a telescopic cylinder.

[0024] Optionally, in the above-described brazing apparatus, the welding seat is a ceramic seat.

[0025] Optionally, in the above-mentioned brazing apparatus, the induction heater is a medium-frequency induction heater.

[0026] Optionally, in the above-described brazing apparatus, a cold blowing nozzle is provided on at least one side of the welding seat in the first direction.

[0027] Optionally, in the above-described brazing apparatus, the temperature of at least one of the first weldment, the second weldment, and the brazing filler metal is measured.

[0028] The brazing apparatus provided in this application includes a welding seat, a clamping component, and an induction heater. A copper terminal is placed on the welding seat, which supports and limits the copper terminal. Aluminum wires are stacked on the copper terminal. The clamping component includes a first clamping part and a second clamping part. The first clamping part clamps the copper terminal on the welding seat, and the second clamping part clamps the aluminum wires on the copper terminal, ensuring that the relative positions of the aluminum wires and copper terminals do not change during the brazing process. The induction heater uses induced current to generate heat, which simultaneously heats the aluminum wires, brazing filler metal, and copper terminal. However, the heating temperature is higher than the melting point of the brazing filler metal but lower than the melting points of the aluminum wires and copper terminals, so that only the brazing filler metal melts during the brazing process. The brazing filler metal diffuses fully with the aluminum wires and copper terminals, forming a strong metallurgical bond. The brazing apparatus disclosed in this application uses induction welding instead of traditional flame welding. The entire welding process is flameless, reducing the risk of fire and preventing damage to the operator's eyesight or skin, thus minimizing the impact on the operator's physical and mental health. Furthermore, during induction welding, only the brazing filler metal melts, while both the first and second welded parts remain solid, reducing welding difficulty. In addition, induction welding has advantages such as fast heating speed and high efficiency, which can shorten welding time, shorten the production cycle, improve production efficiency, and reduce production costs. Attached Figure Description

[0029] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the accompanying drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are merely some examples or embodiments of this application. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort, and this application can be applied to other similar scenarios based on the provided drawings. Unless obvious from the linguistic context or otherwise specified, the same reference numerals in the drawings represent the same structures or operations.

[0030] Figure 1 This is a schematic diagram of the brazing and welding apparatus provided in the embodiments of this application.

[0031] in:

[0032] 1-Welding base; 2-Clamping component; 21-First clamping part; 22-Second clamping part; 3-Induction coil; 4-Aluminum wire; 5-Copper terminal. Detailed Implementation

[0033] The present application will now be described in further detail with reference to the accompanying drawings and embodiments. It is to be understood that the specific embodiments described herein are merely illustrative of the application and not intended to limit it. The described embodiments are only a part of the embodiments of the present application, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of the present application without inventive effort are within the scope of protection of the present application.

[0034] It should be noted that, for ease of description, only the parts relevant to the application are shown in the accompanying drawings. Unless otherwise specified, the embodiments and features described in this application can be combined with each other.

[0035] It should be understood that the terms "system," "apparatus," "unit," and / or "module" used in this application are a method of distinguishing different components, elements, parts, sections, or assemblies at different levels. However, if other terms can achieve the same purpose, they may be replaced by other expressions.

[0036] As indicated in this application and claims, unless the context clearly indicates otherwise, the words "a," "an," "a," and / or "the" are not specifically singular and may include the plural. Generally, the terms "comprising" and "including" only indicate the inclusion of expressly identified steps and elements, which do not constitute an exclusive list, and the method or apparatus may also include other steps or elements. An element defined by the phrase "comprising an..." does not exclude the presence of other identical elements in the process, method, product, or apparatus that includes the element.

[0037] In the description of the embodiments of this application, unless otherwise stated, " / " means "or", for example, A / B can mean A or B; "and / or" in this document is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, and B existing alone. Furthermore, in the description of the embodiments of this application, "multiple" refers to two or more.

[0038] Hereinafter, 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 technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature.

[0039] In related technologies, the connection methods for aluminum wires and copper terminals include fusion welding, pressure welding, and brazing.

[0040] When aluminum wires and copper terminals are connected by fusion welding, the melting point of the aluminum wire is lower than that of the copper terminal. When the aluminum wire melts, the copper terminal remains solid. When the copper terminal melts, much of the aluminum wire has already melted, which increases the difficulty of welding. In addition, the weld is prone to porosity, the weld joint is brittle and prone to cracking, and the welding quality and reliability are low.

[0041] When aluminum conductors and copper terminals are connected by pressure welding, pressure welding is a solid-state welding method. During welding, pressure is used to force the surfaces of the aluminum conductor and copper terminal into direct, tight contact in a solid state, and the temperature of the area to be welded is raised. By adjusting the temperature, pressure, and time, the surfaces of the aluminum conductor and copper terminal are allowed to diffuse sufficiently to achieve interatomic bonding. Pressure welding can improve the joint quality to a certain extent, but it has high requirements for equipment and processes, resulting in high costs for connecting aluminum conductors and copper terminals.

[0042] Brazing is a welding method in which both the filler metal and the workpiece are heated to their melting point (below the melting point of the filler metal) simultaneously, and the liquid filler metal fills the gaps between the solid workpieces to achieve a welded connection. In related technologies, when brazing is used to connect aluminum wires and copper terminals, the traditional gas welding process (oxy-acetylene) is employed. This process involves open flames, posing a fire risk. Furthermore, the open flames can damage the operator's eyesight or skin, which is detrimental to their physical and mental health.

[0043] In addition, gas welding requires high welding skills from the welder, and the welding process is prone to problems such as unstable welding quality, insufficient welding strength and low welding efficiency.

[0044] Figure 1 This is a schematic diagram of the brazing apparatus disclosed in the embodiments of this application. This application uses a dry-type transformer as an example for illustration. When the brazing apparatus is applied to a dry-type transformer, the first welding component is a copper terminal 5, and the second welding component is an aluminum wire 4. The brazing apparatus is used to achieve the brazing connection between the copper terminal 5 and the aluminum wire 4.

[0045] The brazing apparatus disclosed in this application is not only applicable to dry-type transformers, but also to other equipment that requires brazing connections, all of which are within the scope of protection of this application.

[0046] Brazing requires brazing filler metal. The brazing filler metal is sandwiched between the aluminum wire 4 and the copper terminal 5. The melting point of the brazing filler metal is lower than that of the aluminum wire 4 and the copper terminal 5. When the brazing filler metal melts, the liquid brazing filler metal diffuses fully with the aluminum wire 4 and the copper terminal 5 to form a strong metallurgical bond, thereby improving the connection strength between the aluminum wire 4 and the copper terminal 5.

[0047] The brazing apparatus disclosed in this application includes a brazing base 1, a clamping member 2, and an induction heater. The brazing base 1 holds a copper terminal 5 and serves to support and limit its position. An aluminum wire 4 is stacked on top of the copper terminal 5; optionally, the aluminum wire 4 is located on the side of the copper terminal 5 furthest from the brazing base 1. The clamping member 2 includes a first clamping part 21 and a second clamping part 22. The first clamping part 21 clamps the copper terminal 5, and the second clamping part 22 clamps the aluminum wire 4, ensuring that the relative positions of the aluminum wire 4 and the copper terminal 5 do not change during the brazing process. The induction heater includes an induction coil, which is mounted on the brazing base 1 and surrounds the copper terminal 5, the aluminum wire 4, and the brazing filler metal located on the brazing base 1.

[0048] The brazing apparatus disclosed in this application employs induction welding. The induction heater generates magnetic lines of force through alternating current. These magnetic lines of force cut the aluminum wire 4, copper terminal 5, and brazing filler metal, generating eddy currents within them. This causes the aluminum wire 4, copper terminal 5, and brazing filler metal to heat up, and the brazing filler metal melts. The molten brazing filler metal diffuses fully with the aluminum wire 4 and copper terminal 5, forming a strong metallurgical bond. This replaces the traditional flame welding method. The entire welding process is flameless, reducing the risk of fire. It also does not harm the operator's eyesight or skin, minimizing the impact on the operator's physical and mental health.

[0049] The brazing apparatus disclosed in this application has a brazing filler metal with a melting point lower than that of the first and second welded parts. During the brazing process, only the brazing filler metal melts, while the first and second welded parts remain in a solid state. This reduces the difficulty of welding, makes it less prone to porosity, and avoids causing excessive brittleness at the joint. It improves the consistency of welding quality, enhances the welding quality and reliability, and improves the market competitiveness of enterprises.

[0050] The brazing apparatus disclosed in this application employs induction welding. Compared to traditional flame welding, induction welding offers advantages such as faster heating speed and higher efficiency, shortening welding time, reducing production cycles, improving production efficiency, and lowering production costs. Calculations show that the brazing apparatus disclosed in this application can improve efficiency by approximately 50% compared to traditional flame welding.

[0051] The brazing device disclosed in this application clamps the first and second weldment parts using the first clamping part 21 and the second clamping part 22 of the clamping part 2, respectively. Specifically, the first clamping part 21 clamps the copper terminal 5 onto the welding seat 1, and the second clamping part 22 clamps the aluminum wire 4 onto the copper terminal 5, thereby positioning the copper terminal 5 and the aluminum wire 4. In the entire welding process, only one operator is needed to place the first weldment part, the second weldment part, and the brazing filler metal, reducing the number of operators from two to one, which to a certain extent reduces the intensity of manual labor and labor costs; moreover, the welding process is simple and easy to control.

[0052] In summary, the brazing apparatus disclosed in this application can solve the problems of poor welding quality consistency, low welding efficiency, high welding cost and unsafe operation in related technologies, improve the reliability of welding quality of aluminum wire 4 and copper terminal 5, increase welding efficiency, reduce production cost and improve the safety of welding process.

[0053] The heat generated by the induction heater is used to rapidly heat the parts to be welded. During the heating process, a thermometer (such as an infrared thermometer) can be used to monitor the temperature of the welding area in real time. When the temperature of the welding area reaches the melting point of the brazing filler metal, this temperature is maintained for 15 to 20 seconds to allow the filler metal to fully melt, and then heating is stopped. The liquid brazing filler metal wets the base material, fills the gap between the first and second welded parts, and diffuses between the liquid brazing filler metal and the base material (copper terminal 5 and aluminum wire 4) to form a strong metallurgical bond, thereby improving the weld strength.

[0054] After welding is completed, the welded parts are visually inspected and tested by ultrasonic phased array to check for defects such as porosity, slag inclusions and cracks. If surface defects are found, they can be repaired by welding or other methods.

[0055] To ensure the stability of the first welded component on the welding seat 1, optionally, in some embodiments, the welding seat 1 includes a limiting member for limiting the first welded component along a first direction and a second direction, so as to prevent the first welded component from moving along the first direction and the second direction during the welding process.

[0056] Wherein, the first direction and the second direction are perpendicular to each other, and the first direction and the second direction are perpendicular to the pressing direction of the clamping member 2. Optionally, the first direction and the second direction are two mutually perpendicular directions in the horizontal plane. Figure 1 As shown, Figure 1 In this diagram, the X direction is the first direction, the Y direction is the second direction, and the Z direction is the pressing direction. Optionally, the first direction is the length direction of the limiting member, the second direction is the length direction perpendicular to the limiting member, and the length directions of the first welded part and the second welded part are parallel to the length direction of the limiting member.

[0057] In some embodiments, the limiting element is a limiting groove.

[0058] The limiting groove includes a limiting groove, which includes a first groove wall, a second groove wall, a third groove wall, and a groove bottom. The first groove wall, the second groove wall, the third groove wall, and the groove bottom are arranged to form a space for accommodating the first welded part, the second welded part, and the brazing filler metal.

[0059] Optionally, the space enclosed by the first, second, and third trench walls and the trench bottom is adapted to the shape of the first weldment. In some embodiments, the welding seat is semi-cylindrical.

[0060] Specifically, the first and second groove walls are used to limit the first welded part along the second direction. Optionally, the plane containing the first and second groove walls is parallel to the first direction, and the first and second groove walls are arranged parallel to each other along the second direction.

[0061] The third groove wall is parallel to the pressing direction and perpendicular to the first direction. The third groove wall is located at one end of the first groove wall and the second groove wall along the first direction, and can abut against the first welded part to limit the first welded part along the first direction.

[0062] The limiting groove also includes a first groove and a second groove, the first groove and the second groove are connected, wherein the first groove is opposite to the bottom of the groove, and the second groove is opposite to the third groove wall.

[0063] The first welded component is placed into the limiting groove through the first slot and is located at the bottom of the groove. The first welded component can be completely located in the limiting groove. The end of the first welded component away from the third groove wall can also extend out of the limiting groove through the second slot. The part of the second welded component whose length in the first direction exceeds the limiting groove extends out through the second slot.

[0064] In some embodiments, a groove is formed on the side of the first weldment facing the first slot. This groove is used to hold the brazing filler metal and the second weldment. Optionally, the dimensions of the brazing filler metal along the first and second directions are equal to the dimensions of the groove along the first and second directions, and the dimension of the second weldment along the second direction is equal to the dimension of the groove. In some embodiments, the dimensions of the groove are 0.3mm × 12mm × 40mm, and the dimensions of the brazing filler metal are 0.3mm × 12mm × 20mm. Two pieces of brazing filler metal stacked along the pressing direction are placed in the groove to avoid brazing filler metal accumulation or insufficient filling, thereby improving welding quality and welding efficiency.

[0065] The structure of the limiting member is not limited to the above embodiments. Other structures that can limit the first welded member in the first and second directions are all within the protection scope of this application.

[0066] Optionally, the brazing filler metal is zinc-aluminum brazing filler metal (Zn-15Al). Zn-15Al has good fluidity and wettability to copper and aluminum, can achieve good welding results at lower temperatures, can effectively remove oxides on the surface of copper and aluminum, and promote the spread and filling of the brazing filler metal.

[0067] The brazing filler metal can also be one or a combination of tin, nickel and zinc, or at least one or a combination of gold and silver.

[0068] To prevent the brazing filler metal from flowing off course, the brazing apparatus disclosed in this application needs to be tilted during welding. After tilting, the angle between the length direction of the second weldment and the horizontal plane is 10°~20°, and the position where the second weldment is welded to the first weldment is lower than the position where the second weldment is far away from the first weldment.

[0069] Optionally, the first pressing part 21 and the second pressing part 22 are ceramic pressing blocks. For example... Figure 1 As shown, the first pressing part 21 and the second pressing part 22 are plate-shaped structures that are parallel to the pressing direction and perpendicular to the first direction. The plate-shaped structures are made of ceramic material.

[0070] The first pressing part 21 and the second pressing part 22 are not limited to ceramic materials, but can also be other non-metallic materials, all of which are within the scope of protection of this application.

[0071] The shapes of the first clamping part 21 and the second clamping part 22 are not limited to plate shape, but can also be other structural forms that can clamp the first welded part and the second welded part, all of which are within the protection scope of this application.

[0072] In order to optimize the clamping effect of the first clamping part 21 and the second clamping part 22 on the first welded part and the second welded part, the first clamping part 21 includes a first clamping groove adapted to the shape of the first welded part, and the second clamping part 22 includes a second clamping groove adapted to the shape of the second welded part.

[0073] The first and second clamping grooves cooperate with the limiting groove and the recess to improve the clamping effect on the first and second welded parts.

[0074] The movement of the first pressing part 21 and the second pressing part 22 can be achieved by manual driving in conjunction with the locking mechanism.

[0075] The movement of the first clamping part 21 and the second clamping part 22 can also be achieved by a driving member, which drives the first clamping part 21 and the second clamping part 22 to move toward or away from the welding seat 1.

[0076] When the driving member drives the first pressing part 21 and the second pressing part 22 to move toward the welding seat 1, the first pressing part 21 and the second pressing part 22 press against the first welded part and the second welded part respectively; when the driving member drives the first pressing part 21 and the second pressing part 22 to move away from the welding seat 1, the first pressing part 21 and the second pressing part 22 release the pressing against the first welded part and the second welded part respectively.

[0077] Optionally, the welding base 1 is a ceramic base.

[0078] In some embodiments, the first pressing part 21 and the second pressing part 22 share a driving member, that is, the pressing part 2 includes a driving member, which drives the first pressing part 21 and the second pressing part 22 to move simultaneously, so as to realize the synchronous movement of the first pressing part 21 and the second pressing part 22.

[0079] In some embodiments, the clamping member 2 includes two driving members, which are respectively connected to the first clamping part 21 and the second clamping part 22. The two driving members drive the first clamping part 21 and the second clamping part 22 to move. In this embodiment, the first clamping part 21 and the second clamping part 22 can move synchronously or asynchronously.

[0080] Optionally, the driving component is a telescopic cylinder.

[0081] Optionally, the induction heater is a medium-frequency induction heater.

[0082] The induction heater is not limited to a medium-frequency induction heater, but can also be other devices capable of induction welding, all of which are within the scope of protection of this application.

[0083] The welding method of the brazing welding apparatus disclosed in this application is as follows, including:

[0084] Place the first welding component, the brazing filler metal, and the second welding component on the welding seat 1;

[0085] The first pressing part 21 and the second pressing part 22 of the pressing member 2 respectively press the first welded member and the second welded member;

[0086] The induction heater is activated to melt the brazing filler metal, which diffuses with the first and second weldment components to achieve a connection.

[0087] The first welding component, the brazing filler metal, and the second welding component are placed on the welding seat 1. Specifically, before the first welding component, the brazing filler metal, and the second welding component are placed into the welding seat 1, the first welding component, the brazing filler metal, and the second welding component are stacked together. The whole formed by the stacking of the first welding component, the brazing filler metal, and the second welding component is placed on the welding seat 1. Alternatively, the first welding component can be placed on the welding seat 1 first, and then the brazing filler metal and the second welding component can be stacked on the first welding component in sequence. Alternatively, the first welding component and the brazing filler metal can be assembled first, and then the second welding component can be placed on the brazing filler metal.

[0088] The first clamping part 21 and the second clamping part 22 of the clamping member 2 clamp the first welded part and the second welded part respectively, and prepare for welding.

[0089] After the above work is completed, the induction heater is activated to melt the brazing filler metal. The liquid brazing filler metal diffuses with the first and second welded parts to achieve a connection.

[0090] The first weldment is placed on the welding base 1, and then the brazing filler metal and the second weldment are stacked sequentially on top of the first weldment. Specifically, the first weldment is placed on the welding base 1 first, with the non-welding end of the first weldment resting against the third groove wall. Then, the brazing filler metal is placed on the first weldment, and finally, the second weldment is placed on the brazing filler metal. This embodiment discloses a method of placing the first weldment, brazing filler metal, and the second weldment separately, which can reduce the difficulty of arranging the first weldment, brazing filler metal, and the second weldment on the welding base 1.

[0091] Before placing the first weldment, brazing filler metal, and second weldment on the welding seat 1, the process also includes:

[0092] Remove the insulation to expose the second weldment;

[0093] A groove is machined on the first weldment for mounting the brazing filler metal, and the groove is used to place the brazing filler metal and the second weldment.

[0094] Removing the insulation is a surface treatment of the wires to remove the varnish before soldering. Specifically, this includes:

[0095] Cover the junction area with insulating paper, and wrap the base of each wire to be welded with 1-2 layers of water-soaked asbestos cloth (not dripping wet) to protect the base of the wire to be welded.

[0096] Turn on the dust collector / fume extractor and place it on the welding area between the aluminum wire 4 and the copper terminal 5 to be welded;

[0097] Cut aluminum wire connectors to ensure a clean cut with a tolerance of ±0.1mm;

[0098] Paint removal is performed using an induction heater.

[0099] The process of removing the paint using an induction heater involves adjusting the AC current of the induction heater, placing a 20mm-30mm long aluminum wire into the induction heater, heating the aluminum wire until the paint turns into light gray scales on the surface, stopping the heating, and removing the aluminum wire from the induction heater.

[0100] Use pliers to shape the aluminum wire 4, twisting the width of the aluminum wire 4 to be horizontal, so that the aluminum wire 4 can be soldered to the copper terminal 5.

[0101] Clean the burnt paint off the aluminum wire with a metal brush, then use sandpaper to remove the oxide layer from the paint-free area of ​​the aluminum wire 4, and finally clean the surface of the wire with a damp cloth. The area of ​​the aluminum wire to be soldered will be shiny.

[0102] After completing the above steps, use a vacuum cleaner to remove foreign objects from the surface of the copper terminal 5, and then use a dry cloth to clean the surface of the copper terminal 5 again.

[0103] Place the copper terminal 5 on the welding base 1, with the non-welded end face of the copper terminal 5 completely against the third groove wall of the welding base 1. Place two zinc-aluminum brazing filler plates on the copper terminal 5, and then place the aluminum wire 4 to be welded on the zinc-aluminum brazing filler plates. Finally, activate the clamping component 2 to clamp and fix the copper terminal 5 and the aluminum wire 4 through the first clamping part 21 and the second clamping part 22 respectively, to prevent displacement during the welding process.

[0104] The reference current for removing paint from an induction heater is shown in the table below:

[0105]

[0106] A groove is made on the first welded part. The dimensions of the groove along the first direction and the second direction are equal to the dimensions of the brazing filler metal along the first direction and the second direction. After the brazing filler metal is embedded in the groove, the brazing filler metal along the plane of the first direction and the second direction can fill the groove. The molten brazing filler metal can fill the gap between the first welded part and the second welded part, thereby improving the welding quality and the reliability of the welding.

[0107] Optionally, the depth of the groove along the clamping direction is at least twice the thickness of the solder. The selection of the groove and solder thickness is to ensure that solder accumulation or insufficient filling is avoided.

[0108] If there is too little brazing filler metal, the problem of insufficient brazing filler metal will easily occur. On the one hand, it cannot effectively fill the gap between the first and second welded parts, and on the other hand, it cannot play the role of separating the first and second welded parts. After the knife is welded, an electrochemical reaction will occur between the copper terminal 5 and the aluminum wire 4, which will shorten the service life of the connection position.

[0109] Excessive solder can lead to solder buildup, resulting in material waste and excessive solder thickness between the copper terminal 5 and the aluminum wire 4. This can cause an increase in voltage drop at the soldering point, affecting the electrical performance of the soldering point.

[0110] Alternatively, the brazing filler metal can be in sheet form or in wire form.

[0111] When the brazing filler metal is in the form of a welding wire structure, the zinc-aluminum brazing filler metal is placed side by side in the groove along the second direction; the zinc-aluminum brazing filler metal can be in at least two layers along the pressing direction.

[0112] In embodiments where the brazing filler metal is in the form of a welding wire, the bottom of the limiting groove has an arc-shaped groove adapted to the shape of the brazing filler metal.

[0113] The induction heater is activated to melt the solder, specifically...

[0114] Press the start button of the induction heater, adjust the alternating current of the induction heater so that the solder heats up to the melting point of the solder at a preset temperature rise rate, and maintains the temperature at the melting point for a preset time so that the solder melts into a liquid state.

[0115] Adjust the alternating current, specifically by adjusting the welding current according to the table below.

[0116]

[0117] During the heating process, closely monitor the temperature change of the brazing filler metal. Taking zinc-aluminum brazing filler metal (Zn-15Al) as an example, the filler metal is heated to 400℃~450℃ according to the preset temperature rise rate, close to the melting point of zinc-aluminum brazing filler metal (Zn-15Al). After the copper terminal 5 turns red and the filler metal just melts, maintain the temperature of 400℃~450℃ for 15~20 seconds to allow the filler metal to fully melt. During this period, use Φ1.2 zinc-aluminum flux-cored welding wire for appropriate filling. The filler metal and the base metal diffuse fully to form a strong metallurgical bond and improve the welding strength.

[0118] During the heating process, the temperature change of the brazing filler metal is closely monitored using an infrared thermometer.

[0119] Optionally, the preset temperature rate is ≤15℃ / s.

[0120] After the heat preservation is completed, turn off the induction heater, remove the workpiece, and the welding is complete.

[0121] After activating the induction heater to melt the brazing filler metal, and allowing the liquid filler metal to diffuse with the first and second welded parts to achieve a connection, the process further includes:

[0122] The weldment formed by connecting the first weldment, brazing filler metal, and second weldment is cooled to a preset temperature. The clamping parts 21 and 22 are released from their clamping positions on the first and second weldments, and the weldment is removed from the induction heater.

[0123] Cooling can be achieved by using compressed air to cool the weldment to a preset temperature, which in some embodiments is 80°C.

[0124] The cooling method can also be water cooling or natural cooling.

[0125] After cooling, use a metal brush or sandpaper to clean the surface oxide layer of the welded area until the welded area is shiny.

[0126] After the workpiece exits the induction heater, the following also applies:

[0127] Welding quality inspection and performance testing are performed on the welded parts.

[0128] Welding quality inspection includes:

[0129] Visually inspect the surface of the weldment for sharp corners, burrs, and missing welds;

[0130] X-ray inspection of the weldment is performed, optionally using an X-ray non-destructive testing instrument;

[0131] Metallographic analysis of the weldment is performed. Optionally, metallographic analysis is performed using a metallographic microscope and a scanning electron microscope to check whether there are defects such as porosity, slag inclusions and cracks in the welded area.

[0132] Performance testing includes checking the electrical performance of the welded parts, and verifying whether the welded parts meet the electrical performance requirements of the dry-type transformer through resistance testing, so as to ensure the stability and reliability of current transmission.

[0133] If surface defects are found, they can be repaired by methods such as welding.

[0134] The above description is merely a preferred embodiment of this application and an explanation of the technical principles employed, and is not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. The scope of this application is not limited to technical solutions formed by specific combinations of the above-described technical features, but should also cover other technical solutions formed by arbitrary combinations of the above-described technical features or their equivalents without departing from the above-described application concept. For example, technical solutions formed by substituting the above features with (but not limited to) technical features with similar functions disclosed in this application.

Claims

1. A brazing welding apparatus, characterized in that, Used to achieve the brazing connection between the first and second welded parts; The brazing device includes a welding seat (1), a clamping component (2), and an induction heater; The first weldment and the second weldment are stacked on the welding seat (1); The clamping member (2) includes a first clamping part (21) and a second clamping part (22), wherein the first clamping part (21) is used to clamp the first welded part, and the second clamping part (22) is used to clamp the second welded part; The induction coil (3) of the induction heater is mounted on the welding base (1). The induction heater is used to melt the brazing filler metal. The liquid brazing filler metal diffuses with the first welding piece and the second welding piece to achieve connection.

2. The brazing apparatus according to claim 1, characterized in that, The welding seat (1) includes a limiting member, which is used to limit the first welding part in a first direction and a second direction. The first direction and the second direction are perpendicular to each other, and the first direction and the second direction are perpendicular to the pressing direction of the clamping member (2).

3. The brazing apparatus according to claim 2, characterized in that, The limiting component is a limiting groove, which includes a first groove wall, a second groove wall, a third groove wall, and a groove bottom; The first groove wall and the second groove wall are used to limit the first welded part along the second direction; The third groove wall is parallel to the pressing direction and perpendicular to the first direction, and the third groove wall is used to limit the first welded part along the first direction; The limiting groove also includes a first groove and a second groove, wherein the first groove and the second groove are connected. The first slot is opposite to the bottom of the tank, and the first welded part is placed on the bottom of the tank through the first slot; The second slot is opposite to the third slot wall, and the portion of the second welded part and the first welded part whose length along the first direction exceeds the limiting slot extends through the second slot.

4. The brazing apparatus according to claim 1, characterized in that, Both the first pressing part (21) and the second pressing part (22) are ceramic pressing blocks.

5. The brazing apparatus according to claim 1 or 4, characterized in that, The first pressing part (21) includes a first pressing groove that cooperates with the first welded part, and the second pressing part (22) includes a second pressing groove that cooperates with the second welded part.

6. The brazing apparatus according to any one of claims 1-4, characterized in that, The clamping member (2) further includes a driving member, which is used to drive the first clamping part (21) and the second clamping part (22) to move; The first pressing part (21) and the second pressing part (22) share the driving member, or there are two driving members, and the two driving members are respectively connected to the first pressing part (21) and the second pressing part (22).

7. The brazing apparatus according to claim 6, characterized in that, The driving component is a telescopic cylinder.

8. The brazing apparatus according to any one of claims 1-4, characterized in that, The welding seat (1) is a ceramic seat; And / or, The induction heater is a medium-frequency induction heater.

9. The brazing apparatus according to claim 2, characterized in that, The welding seat is provided with a cold blowing nozzle on at least one side in the first direction.

10. The brazing apparatus according to claim 1, characterized in that, It also includes a thermometer for measuring the temperature of at least one of the first weldment, the second weldment, and the brazing filler metal.

Images