An ultrahigh frequency induction brazing device and method for an electromagnetic relay contact spring system

Abstract

This invention relates to the field of electromagnetic relay manufacturing technology, and discloses an ultra-high frequency induction brazing device for an electromagnetic relay contact spring system, comprising: a worktable, a fixture, a moving mechanism, and an ultra-high frequency induction brazing machine; the fixture is disposed on the worktable surface and is used to clamp and fix the contact spring system; during welding, a spring sheet is sleeved on the Kovar alloy lead-out rod in the contact spring system to form a welding point between the two; the output end of the moving mechanism can move along a first direction and a second direction, and the induction brazing head of the ultra-high frequency induction brazing machine is disposed on the moving mechanism; during operation, the moving mechanism drives the induction brazing head to move along the first direction and the second direction, so that the induction coil of the induction brazing head is aligned with each welding point. This device adopts non-contact induction heating, completely avoiding the use of carbon rod electrodes, eliminating the generation of excess carbon powder from the source, and greatly improving the internal cleanliness and long-term operational reliability of the electromagnetic relay.

Description

Technical Field

[0001] This invention relates to the field of electromagnetic relay manufacturing technology, specifically to an ultra-high frequency induction brazing device and method for an electromagnetic relay contact spring system. Background Technology

[0002] Electromagnetic relays are one of the core components of electrical control systems, and their reliability directly affects the operational safety of the entire system. The contact spring system, as a key component of the relay, typically consists of a Kovar alloy base plate, a Kovar alloy lead rod, a spring, and a glass insulator. The electrical connection between the lead rod and the spring is achieved through a brazing process.

[0003] Currently, resistance welding is the most common method used in the industry for this connection. Specifically, a carbon electrode is used to contact the weld joint, and welding is achieved by instantaneous heating with a high current. However, this traditional process has the following drawbacks: Foreign matter problem: Carbon rod electrodes wear and peel off at high temperatures, producing carbon powder particles that remain around the solder joints and inside the relay cavity. These conductive foreign matter are difficult to clean completely and may migrate when the electromagnetic relay is subjected to vibration or impact, affecting the contact resistance of the contacts, causing mechanical jamming that affects the engagement and release, damaging the insulation performance of the relay, and seriously threatening the long-term reliability of the electromagnetic relay.

[0004] Working conditions and environmental issues: The carbon powder generated during the welding process permeates the air, polluting the working environment and posing a health hazard to operators, which does not meet the requirements of modern clean production.

[0005] Therefore, there is an urgent need for a non-contact, pollution-free welding process to replace the traditional resistance welding process. Summary of the Invention

[0006] The purpose of this invention is to provide an ultra-high frequency induction brazing device for an electromagnetic relay contact spring system, so as to solve the problems in the above-mentioned background technology that the use of carbon rod electrodes to contact the solder joints easily produces excess material and pollutes the environment.

[0007] Another objective of this invention is to provide an ultra-high frequency induction brazing method for an electromagnetic relay contact spring system.

[0008] To achieve the above objectives, the present invention provides the following technical solution: An ultra-high frequency induction brazing device for an electromagnetic relay contact spring system includes: Workbench; A clamp is provided on the table surface of the workbench. The clamp is used to hold and fix the contact spring system. During welding, a spring is sleeved on the Kovar alloy lead-out rod of the corresponding contact spring system so that a welding point is formed between the two. A moving mechanism, the output end of which can move along a first direction and a second direction, the first direction and the second direction being perpendicular to each other and parallel to the table surface; The ultra-high frequency induction brazing machine has its main unit located on one side of the worktable, and its induction brazing head mounted on a moving mechanism. During operation, the moving mechanism drives the induction brazing head to move along a first direction and a second direction, ensuring that the induction coil of the induction brazing head aligns with each point to be welded. This design utilizes non-contact induction heating, completely eliminating the use of carbon rod electrodes and preventing the generation of excess carbon powder, thus significantly improving the internal cleanliness and long-term reliability of the electromagnetic relay.

[0009] Furthermore, the fixture includes a base, positioning inserts, and a contact gap positioning plate. The upper surface of the base has a receiving groove for placing the Kovar alloy base plate. The positioning insert has multiple insertion holes; when the positioning insert mates with the Kovar alloy base plate, it inserts through the insertion holes between the Kovar alloy lead-out rods to form a bearing plane between them. The contact gap positioning plate is located on the upper surface of the base and has a cavity corresponding to the Kovar alloy base plate. The contact gap positioning plate includes contact gap limiting inserts that extend into the cavity along both sides to support the contact gap between the springs. Through the above configuration, the positioning inserts ensure consistent spacing between the lower end of the spring and the surface of the Kovar alloy base plate, ultimately achieving consistent spring height. The spring is a silver-magnesium-nickel spring. The contact gap limiting inserts on both sides of the cavity meet the requirements for contact gaps on both sides of the spring system.

[0010] Furthermore, the upper surface of the base has a first platform, a second platform, and a third platform arranged sequentially along a first direction; the second platform protrudes from the first and third platforms, and the second platform has a receiving groove for placing the Kovar alloy base plate; the lower surface of the contact gap positioning plate has a fourth platform, a fifth platform, and a sixth platform arranged sequentially along the first direction; the fourth and sixth platforms protrude from the fifth platform, and the fifth platform has a cavity corresponding to the Kovar alloy base plate. In use, the first and fourth platforms, the second and fifth platforms, and the third and sixth platforms are vertically aligned. Through the above arrangement, a stepped portion is formed between the first and second platforms and between the second and third platforms. The shape of the lower surface of the contact gap positioning plate matches the stepped portion, facilitating docking between the two and preventing the contact gap positioning plate from moving left and right.

[0011] Furthermore, both the first and third platforms are equipped with limit posts, and the fourth and sixth platforms have limit holes corresponding to the limit posts. With these features, the contact gap positioning plate can directly connect to the base through the limit posts, improving work efficiency and accuracy.

[0012] Furthermore, the contact gap positioning plate also includes a base plate and a pressure plate; the lower surface of the base plate is correspondingly arranged with a fourth platform, a fifth platform, and a sixth platform, the fifth platform having a cavity that extends vertically through it, and the upper surfaces of the fourth and sixth platforms each having a limiting groove, which communicates with the cavity; one end of the contact gap insert is located in the limiting groove, and the other end extends into the cavity. By arranging the contact gap insert as described above, the contact gap on the left and right sides of the contact spring system meets the requirements.

[0013] Furthermore, the contact gap limiting insert includes a connecting positioning section and an insertion section; the positioning section is disposed within a limiting groove, and the insertion section extends into the cavity, the size of which corresponds to the required contact gap between the springs. During brazing, the contact gap limiting insert can separate adjacent springs, preventing them from getting too close and ensuring that the contact gap between the springs meets the requirements.

[0014] Furthermore, the workbench surface is provided with an opening for accommodating a moving mechanism, and the induction brazing head is disposed on the moving mechanism. This arrangement ensures that the height of the induction brazing head corresponds to that of the fixture.

[0015] Furthermore, the opening is located on one side of the worktable. This arrangement facilitates the operation of the moving mechanism. Furthermore, the moving mechanism includes a base, a first slide rail assembly, a second slide rail assembly, a support base, and a locking assembly. The first slide rail assembly is disposed on the base, and its output end is reciprocating along a first direction (the X direction). The second slide rail assembly is disposed on the output end of the first slide rail assembly, and its output end is reciprocating along a second direction (the Y direction). The support base is disposed on the output end of the second slide rail assembly. The locking assembly is fixed to the support base and is used to fix the induction brazing head. The first and second slide rail assemblies are XY-axis precision slide rails, which can move the induction brazing head along the XY direction, so that the induction coil of the induction brazing head is sequentially aligned with each point to be welded, thereby improving production efficiency.

[0016] Furthermore, the end of the induction coil near the contact spring system has a bent portion, which includes an induction ring segment and a connecting segment. The induction ring segment is connected to the main body of the induction coil via the connecting segment. By providing the bent portion, the induction coil can concentrate heat in the welding area, preventing the non-welding areas of the workpiece from being affected by heat.

[0017] Furthermore, the induction coil is made of pure copper tubing, with cooling water flowing inside to cool the coil and improve its service life.

[0018] A method for ultra-high frequency induction brazing of an electromagnetic relay contact spring system includes the following steps: S1. Workpiece preparation: Roll the root of the spring sheet onto the corresponding Kovar alloy lead-out rod one by one to form a welding point between them; S2. Clamping: Fixing the workpiece with the welding point to be formed in place; S4. Place brazing filler metal: Place brazing filler metal at each point to be soldered; S5. Ultra-high frequency induction brazing: Move the induction brazing head so that the induction coil is facing one of the points to be welded, start the ultra-high frequency induction brazing machine, set the power parameters, and use a high-frequency alternating magnetic field to generate eddy currents on the surface of the Kovar alloy lead rod and the spring and heat them rapidly; during the heating process, the brazing filler melts and fully penetrates and fills the brazing gap between the spring and the Kovar alloy lead rod under capillary action. S6. Weld each weld point in sequence: After completing the welding of one weld point, turn off the induction heating power of the ultra-high frequency induction brazing machine; repeat step S3 until all weld points of a single product are welded in sequence. S7. Workpiece Cooling and Unloading: After all welding points are completed, allow the workpiece to cool naturally or with auxiliary cooling; remove the welded spring system components.

[0019] Furthermore, the brazing gap is 0.08-0.10 mm.

[0020] The present invention has the following advantages over the prior art: This invention discloses an ultra-high frequency induction brazing device for an electromagnetic relay contact spring system, comprising a worktable, a clamp, a moving mechanism, and an ultra-high frequency induction brazing machine. The clamp is arranged on the worktable surface and is used to hold a Kovar alloy base plate. The moving mechanism, in cooperation with the worktable, drives the induction brazing head of the ultra-high frequency induction brazing machine to move along a first direction and a second direction, so that the induction coil of the induction brazing head aligns one-to-one with each welding point on the Kovar alloy base plate. Employing a non-contact ultra-high frequency induction heating principle, the generation of excess carbon powder is eliminated at the source, greatly improving the internal cleanliness and long-term operational reliability of the electromagnetic relay. It also improves the production environment, as the entire process is smokeless and free of carbon powder pollution, significantly improving the working conditions of operators and conforming to the modern green and environmentally friendly manufacturing concept.

[0021] The fixture of this invention includes a base, positioning inserts, and a contact gap positioning plate. The upper surface of the base has a receiving groove for placing a Kovar alloy base plate. The positioning insert has multiple insertion holes. When the positioning insert mates with the Kovar alloy base plate, it is inserted through the insertion holes between the Kovar alloy lead-out rods to form a bearing plane between them. A spring is then fitted onto the lead-out rod, with its bottom resting on the bearing plane. This ensures that the lower end of the spring is aligned with the surface of the Kovar alloy base plate during brazing, ultimately achieving a consistent spring height. The contact gap positioning plate includes a contact gap limiting insert, a base plate, and a pressure plate. The base plate corresponds to the base for splicing. The contact gap limiting insert is fixed in a limiting groove on the base plate by the pressure plate and extends into the cavity to separate adjacent springs, ensuring the contact gap between the springs meets requirements. In other words, this fixture can position the Kovar alloy base plate and springs, improving brazing efficiency. Using this fixture ensures that the relative positions of all springs and lead-out rods are fixed, and the brazing gap is uniform and stable.

[0022] 3. The ultra-high frequency induction brazing method of the electromagnetic relay contact spring system in this invention adopts the principle of non-contact ultra-high frequency induction heating. The Kovar alloy lead rod and the surface of the spring are rapidly heated by the high frequency alternating magnetic field. During the heating process, the columnar brazing filler melts and fully penetrates and fills the tiny gap between the spring and the lead rod under capillary action, which fundamentally eliminates excess carbon powder, significantly improves the reliability and consistency of the product, and improves the production environment.

[0023] 4. Excellent and Consistent Welding Quality: Ultra-high frequency induction heating features a skin effect, resulting in rapid and concentrated heating with a small heat-affected zone. Combined with precise control of ultra-high frequency induction brazing parameters and a bent coil design, it avoids the influence of heat on non-welding areas of the workpiece, achieving precise energy delivery and ensuring uniform heat input at each weld point. This allows the silver-copper-phosphorus brazing filler metal to evenly and fully fill the weld seam through capillary action, forming a dense, smooth, and high-strength brazed joint with a high yield rate. Good material compatibility: The selected silver-copper-phosphorus brazing filler metal is a self-fluxing filler metal; its phosphorus element effectively reduces the oxide film on the metal surface, eliminating the need for additional flux and avoiding the potential corrosion risk from flux residue. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the overall structure of the ultra-high frequency induction brazing device of the electromagnetic relay contact spring system in an embodiment of the present invention. Figure 2 This is a schematic diagram of the clamping system for the contact spring system in the ultra-high frequency induction brazing device of the electromagnetic relay contact spring system in an embodiment of the present invention. Figure 3 This is a schematic diagram of the fixture in the ultra-high frequency induction brazing device of the electromagnetic relay contact spring system in an embodiment of the present invention; Figure 4 for Figure 3 Schematic diagram of the central base; Figure 5 for Figure 3 A schematic diagram of the structure of the positioning insert; Figure 6 for Figure 3 Schematic diagram of the middle substrate; Figure 7 for Figure 3 Schematic diagram of the structure of the middle contact gap limiting insert; Figure 8 for Figure 3 Schematic diagram of the intermediate pressure plate; Figure 9 This is a schematic diagram of the moving mechanism in the ultra-high frequency induction brazing device of the electromagnetic relay contact spring system in an embodiment of the present invention. Figure 10 This is a schematic diagram showing the relative position of the induction coil and the workpiece in the ultra-high frequency induction brazing device of the electromagnetic relay contact spring system in an embodiment of the present invention. In the diagram: 1. Workbench; 101. Opening; 2. Fixture; 201. Base; 2011. Receiving groove; 2012. First platform; 2013. Second platform; 2014. Third platform; 202. Positioning insert; 2021. Insertion hole; 203. Contact gap positioning plate; 2031. Cavity; 2032. Fourth platform; 2033. Fifth platform; 2034. Sixth platform; 2035. Base plate; 2036. Pressure plate; 2037. Limiting groove; 204. Contact gap limiting insert; 2041. Positioning section; 2042. Insertion section; 3. Moving mechanism; 301. Base; 302. First slide rail assembly; 303. Second slide rail assembly; 304. Support base; 305. Locking assembly; 4. Induction brazing head; 5. Induction coil; 501. Induction loop segment; 502. Connecting segment; 6. Kovar alloy base plate; 7. Kovar alloy lead-out rod; 8. Spring. Detailed Implementation

[0025] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0026] It should be noted that in the description of this invention, the terms "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", and "outer" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0027] Furthermore, it should be understood that, for ease of description, the dimensions of the various components shown in the accompanying drawings are not drawn to actual scale.

[0028] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined or described in one figure, it will not need to be further discussed and described in the description of the subsequent figures.

[0029] Example: refer to Figure 1 , Figure 2 , Figure 7 and Figure 8 An ultra-high frequency induction brazing device for an electromagnetic relay contact spring system includes: a workbench 1, a clamp 2, a moving mechanism 3, and an ultra-high frequency induction brazing machine. The clamp 2 is disposed on the table surface of the workbench 1 and is used to clamp and fix the contact spring system. During welding, a spring plate 8 is sleeved on the Kovar alloy lead-out rod 7 in the contact spring system to form a welding point between them. The output end of the moving mechanism 3 can move along a first direction and a second direction. The first direction and the second direction are perpendicular to each other and parallel to the table surface of the workbench 1. In this embodiment, the first direction is the X direction in the horizontal plane, and the second direction is the Y direction in the horizontal plane. The main unit of the ultra-high frequency induction brazing machine is located on one side of the workbench 1, and the induction brazing head 4 of the ultra-high frequency induction brazing machine is disposed on the moving mechanism. During operation, the moving mechanism 3 drives the induction brazing head 4 to move along the first direction and the second direction so that the induction coil 5 of the induction brazing head 4 is aligned with each welding point. The ultra-high frequency induction brazing machine in this embodiment is purchased from the market. With the above setup, non-contact induction heating is used, completely avoiding the use of carbon rod electrodes, eliminating the generation of excess carbon powder from the source, and greatly improving the internal cleanliness and long-term operational reliability of the electromagnetic relay.

[0030] Specifically, refer to Figure 2 and Figure 3The clamp 2 includes a base 201, a positioning insert 202, and a contact gap positioning plate 203. The upper surface of the base 201 has a receiving groove 2011 for placing the Kovar alloy base plate 6. The positioning insert 202 has multiple insertion holes 2021. When the positioning insert 202 mates with the Kovar alloy base plate 6, the positioning insert 202 is inserted through the insertion holes 2021 between the Kovar alloy lead-out rods 7 to form a bearing plane between the Kovar alloy lead-out rods 7. The spring 8 is fitted onto the Kovar alloy lead-out rod 7, with its bottom end contacting the bearing plane. The contact gap positioning plate 203 is disposed on the upper surface of the base 201. The contact gap positioning plate 203 has a cavity 2031 corresponding to the Kovar alloy base plate. The contact gap positioning plate 203 includes a contact gap limiting insert 204, which extends into the cavity 2031 along both sides to support the contact gap between the springs. Through the above arrangement, the positioning insert 202 ensures that the distance between the lower end of the spring and the surface of the Kovar alloy base plate is consistent, ultimately achieving a consistent spring height. The spring is a silver-magnesium-nickel spring. The contact gap limiting inserts 204 on both sides of the cavity 2031 are inserted between the springs, ensuring that the contact gap on both sides of the contact spring system meets the requirements. Using this fixture ensures that the relative positions of all springs and the lead-out rod are fixed, and the brazing gap is uniform and stable.

[0031] refer to Figures 4-8 The upper surface of the base 201 has a first platform 2012, a second platform 2013, and a third platform 2014 arranged sequentially along a first direction; the second platform 2013 protrudes from the first platform 2012 and the third platform 2014, and the second platform 2013 has a receiving groove 2011 for placing the Kovar alloy base plate 6; the lower surface of the contact gap positioning plate 203 has a fourth platform 2032, a fifth platform 2033, and a sixth platform 2034 arranged sequentially along a first direction; the fourth platform 2032 and the sixth platform 2034 protrude from the fifth platform 2033, and the fifth platform 2033 has a cavity corresponding to the Kovar alloy base plate 6. In use, the first platform 2012 and the fourth platform 2032, the second platform 2013 and the fifth platform 2033, and the third platform 2014 and the sixth platform 2034 are vertically opposite each other. With the above settings, a stepped portion is formed between the first platform 2012 and the second platform 2013, and between the second platform 2013 and the third platform 2014. The shape of the lower surface of the contact gap positioning plate 203 matches the stepped portion, which facilitates the docking of the two and prevents the contact gap positioning plate from moving left and right.

[0032] Specifically, both the first platform 2012 and the third platform 204 are equipped with limit posts, and the fourth platform 2032 and the sixth platform 2034 have limit holes corresponding to the limit posts. With this configuration, the contact gap positioning plate can directly connect to the base through the limit posts, improving work efficiency and accuracy. In practice, the first platform 2012, the third platform 204, the fourth platform 2032, and the sixth platform 2034 can also have corresponding bolt holes to fix them together with bolts.

[0033] refer to Figure 7 The contact gap positioning plate 203 further includes a base plate 2035 and a pressure plate 2036. A fourth platform 2032, a fifth platform 2033, and a sixth platform 2034 are correspondingly arranged on the lower surface of the base plate 2035. The fifth platform 2033 has a through-cavity 2031. Limiting grooves 2037 are formed on the upper surfaces of the fourth platform 2032 and the sixth platform 2034, and these limiting grooves 2037 communicate with the cavity 2031. One end of the contact gap insert 204 is located within the limiting groove 2037, and the other end extends into the cavity 203. By arranging the contact gap insert 204 as described above, the insert extends between two adjacent springs, fixing the interval between the springs and ensuring that the contact gaps on both sides of the contact spring system meet the requirements.

[0034] refer to Figure 7 The contact gap limiting insert includes a positioning section 2041 and an insertion section 2042 connected to each other. The positioning section 2041 is disposed within a limiting groove 2037, and the insertion section 2042 extends into the cavity. The size of the insertion section 2042 corresponds to the required contact gap between the springs. During brazing, the contact gap limiting insert can separate adjacent springs, preventing the springs from getting too close and ensuring that the contact gap between the springs meets the requirements.

[0035] In practice, the entire fixture is made of high-temperature resistant material, eliminating the need for conductive materials. (Reference) Figure 4 , Figure 8 , Figure 6 Bolt holes are provided on the first platform 2012 and the third platform 2014 of the base 201, which correspond to the bolt holes in the upper limit groove 2037 of the substrate 2035, thereby connecting the substrate 2035 to the base 201 and preventing the substrate 2035 from moving. Bolt holes corresponding to the pressure plate 2036 are also provided on the substrate 2035, so that the pressure plate 2036 is fixed to the substrate 2035, thereby covering the contact gap limiting insert 204 and preventing the contact gap limiting insert 204 from coming out and affecting the contact gap.

[0036] The workbench 1 has an opening 101 on its surface for housing the moving mechanism 3, and the induction brazing head 4 is mounted on the moving mechanism 3. This arrangement ensures that the height of the induction brazing head 4 corresponds to the fixture. The opening 101 is located on one side of the workbench 1, facilitating operation of the moving mechanism.

[0037] The moving mechanism 3 includes a base 301, a first slide rail assembly 302, a second slide rail assembly 303, a support base 304, and a locking assembly 305. The first slide rail assembly is disposed on the base, and its output end can reciprocate along a first direction (the X direction). The second slide rail assembly is disposed on the output end of the first slide rail assembly, and its output end can reciprocate along a second direction (the Y direction). The support base is disposed on the output end of the second slide rail assembly. The locking assembly is fixed to the support base and is used to fix the induction brazing head. The first and second slide rail assemblies use existing XY-direction precision slide rails, which can be controlled by a control program or moved manually. This mechanism can drive the induction brazing head to move along the XY direction, allowing the induction coil of the induction brazing head to sequentially align with each point to be welded, thus improving production efficiency. The locking assembly 305 uses existing positioning pins, locking screws, etc., to mount the induction head onto the support base 304.

[0038] The induction coil 5 has a bent portion at one end near the contact spring system. The bent portion includes an induction ring segment 501 and a connecting segment 502. The induction ring segment 501 is connected to the main body of the induction coil 5 through the connecting segment 502. By providing the bent portion, the induction coil can concentrate heat in the welding area, avoiding the influence of heat on the non-welding areas of the workpiece.

[0039] The induction coil 5 is made of pure copper tubing, with cooling water circulating inside to cool it and extend its service life. The ultra-high frequency induction brazing machine has a built-in cooling water circulation system for the induction coil, eliminating the need for additional design.

[0040] Using the aforementioned device, a non-contact brazing heating method is employed, utilizing an ultra-high frequency induction brazing machine and a bent induction coil to melt the brazing filler metal and fill the weld seam through capillary action. A moving mechanism then moves the induction coil to sequentially complete the welding of all joints. This device completely eliminates carbon powder contamination, significantly improves the reliability of the relay and the consistency of welding quality, and also improves the production environment. The fixture in this device is used to fix the spring and the lead-out rod, and to control the contact gap between them, while ensuring that the brazing gap meets the requirements. In this embodiment, the rated power of the ultra-high frequency induction brazing machine is 6KW, and the frequency range is 800KHz~1000KHz.

[0041] A method for ultra-high frequency induction brazing of an electromagnetic relay contact spring system includes the following steps: S1. Workpiece preparation: Place the coiled ends of the reeds one by one onto the corresponding Kovar alloy lead-out rods to form a welding point between them. Specifically, first place the Kovar alloy base plate with the Kovar alloy lead-out rods into the receiving groove, then insert the positioning inserts into the upper surface of the Kovar alloy base plate, with the Kovar alloy lead-out rods located in the corresponding insertion holes, so that the positioning inserts form a bearing plane between each Kovar alloy lead-out rod, which is used to unify the distance from the reeds to the Kovar alloy base plate to ensure that the reed height is consistent. Then, place the coiled ends of the reeds one by one onto the corresponding Kovar alloy lead-out rods.

[0042] S2. Clamping: Fix the workpiece with the welding point to be formed; specifically, cover the upper surface of the base with the contact gap positioning plate. Since the contact gap positioning plate integrates the contact gap limiting insert, the contact gap limiting insert is inserted between the two springs in the X direction, so that the contact gap on the left and right sides of the Kovar alloy base plate meets the requirements.

[0043] S4. Placing the brazing filler metal: Place the brazing filler metal at each point to be soldered; the filler metal is silver-copper-phosphorus filler metal, which is a self-fluxing filler metal. Its phosphorus element can effectively reduce the oxide film on the metal surface, eliminating the need to add extra flux and avoiding the potential corrosion risk caused by flux residue.

[0044] S5. Ultra-high frequency induction brazing: Move the induction brazing head so that the induction coil is directly facing one of the points to be welded. Start the ultra-high frequency induction brazing machine, set the power parameters, and use a high-frequency alternating magnetic field to generate eddy currents on the surface of the Kovar alloy lead-in rod and the spring, which are then rapidly heated. During the heating process, the brazing filler metal melts and, under capillary action, fully penetrates and fills the brazing gap between the spring and the Kovar alloy lead-in rod. Specifically, the induction brazing head is mounted on the moving mechanism 3, and the movement of the first and second slide rail assemblies drives the induction brazing head to move. Heating is achieved by generating eddy currents on the surface of the lead-in rod and the spring using an ultra-high frequency alternating magnetic field. The head of the induction coil is bent to concentrate heat in the welding area, preventing the non-welding areas of the workpiece from being affected by heat. In use, the power of the ultra-high frequency induction brazing machine is 60%~90%, and the time is 1~4 seconds.

[0045] S6. Weld each weld point in sequence: After completing the welding of one weld point, turn off the induction heating power of the ultra-high frequency induction brazing machine; repeat step S3 until all weld points of a single product are welded in sequence; output the same parameter for each weld point, which is pre-set on the ultra-high frequency induction brazing machine.

[0046] S7. Workpiece Cooling and Unloading: After all welding points are completed, allow the workpiece to cool naturally or with auxiliary cooling; remove the welded contact spring system assembly. Specifically, first remove the contact gap positioning plate, then pull out the positioning insert, and remove the contact spring system from the receiving groove.

[0047] To ensure welding quality, the brazing gap is controlled within 0.08-0.10mm, such as 0.08mm, 0.09mm, and 0.10mm. Maintaining the brazing gap requires controlling the quality of the incoming spring sheets. Simultaneously, this fixture ensures that the relative positions of all spring sheets and the lead-out rods are fixed, resulting in a uniform and stable brazing gap.

[0048] like Figure 1 , Figure 2 , Figure 7 , Figure 8 As shown, the implementation process of the present invention is as follows: First, the Kovar alloy base plate 6 is placed into the receiving groove 2011 of the fixture 2, and the positioning insert 202 is inserted. Then, the root coils of the six silver-magnesium-nickel springs are respectively placed onto the six Kovar alloy lead-out rods 7, and then the contact gap positioning plate 203 is fastened and locked. This fixture is made of high-temperature resistant material and does not require conductive material. It has a receiving groove and positioning groove to accommodate the Kovar alloy base plate 6. The receiving groove and positioning insert 202 can ensure that the axial and radial positions of all springs 8 and Kovar alloy lead-out rods 7 are accurate. The integrated contact gap limiting insert 204 can ensure that the contact gap meets the requirements and control the brazing gap within the ideal range of 0.08-0.10mm.

[0049] After clamping, a columnar silver-copper-phosphorus brazing filler metal is placed at the connection between the first Kovar alloy lead-out rod 7 and the spring 8 to be welded. Then, the clamp 2 is fixed to the induction brazing workbench 1 (fixed by existing fixing means such as bolts).

[0050] The moving mechanism drives the induction brazing head 4 to move, bringing the bent induction coil 5 directly above the first weld point. The bent induction coil is made of pure copper tubing with internal cooling water. Its bent shape is designed to prevent the non-welding areas of the workpiece from being affected by heat, and it matches the structure of the lead-out rod and spring to achieve efficient heating.

[0051] The ultra-high frequency induction brazing machine is started, outputting an ultra-high frequency current (frequency range 800KHz~1000KHz). The high-frequency alternating magnetic field induces a strong eddy current heating effect on the coiled surfaces of the highly conductive Kovar alloy lead-out rod 7 and the root of the spring 8, causing the temperature to rise rapidly to above the melting point of the brazing filler metal (approximately 800℃) within seconds. The brazing filler metal melts instantly and, thanks to its excellent wetting and capillary action, is drawn in and fills the entire brazing gap. Due to the extremely short heating time (usually completed within 2-3 seconds), the heat input is precisely controlled, preventing ablation of the spring and lead-out rod components and thermal damage to the glass insulator.

[0052] After one solder joint is completed, the equipment automatically stops heating (by pre-setting the ultra-high frequency induction brazing machine). The moving mechanism continues to move, positioning the induction coil 5 above the next solder joint, and repeats the above heating process until all solder joints are completed.

[0053] After the welded components have cooled naturally in the air, they can be removed from the fixture to obtain a high-quality spring system component with full, smooth brazing seams and no foreign matter contamination.

[0054] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. An ultra-high frequency induction brazing device for an electromagnetic relay contact spring system, characterized in that, include: Workbench; A clamp is provided on the table surface of the workbench. The clamp is used to hold and fix the contact spring system. During welding, a spring is sleeved on the Kovar alloy lead-out rod in the contact spring system so that multiple welding points are formed between the two. A moving mechanism, the output end of which can move along a first direction and a second direction, the first direction and the second direction being perpendicular to each other and parallel to the table surface; An ultra-high frequency induction brazing machine, wherein the main unit of the ultra-high frequency induction brazing machine is located on one side of the workbench, and the induction brazing head of the ultra-high frequency induction brazing machine is set on the moving mechanism; during operation, the moving mechanism drives the induction brazing head to move along the first direction and the second direction, so that the induction coil of the induction brazing head is aligned with each point to be welded.

2. The ultra-high frequency induction brazing device for the electromagnetic relay contact spring system according to claim 1, characterized in that: The fixture includes a base, positioning inserts, and a contact gap positioning plate. The upper surface of the base has a receiving groove for placing a Kovar alloy base plate. The positioning insert has multiple insertion holes. When the positioning insert mates with the Kovar alloy base plate, it is inserted through the insertion holes between the Kovar alloy lead-out rods to form a bearing plane between them. The contact gap positioning plate is located on the upper surface of the base and has a cavity corresponding to the Kovar alloy base plate. The contact gap positioning plate includes a contact gap limiting insert that extends into the cavity along both sides to support the contact gap between the springs.

3. The ultra-high frequency induction brazing device for the electromagnetic relay contact spring system according to claim 2, characterized in that: The upper surface of the base has a first platform, a second platform, and a third platform arranged sequentially along a first direction; the second platform protrudes from the first platform and the third platform, and the second platform has a receiving groove for placing the Kovar alloy base plate; the lower surface of the contact gap positioning plate has a fourth platform, a fifth platform, and a sixth platform arranged sequentially along the first direction; the fourth platform and the sixth platform protrude from the fifth platform, and the fifth platform has a cavity corresponding to the Kovar alloy base plate. In use, the first platform and the fourth platform, the second platform and the fifth platform, and the third platform and the sixth platform are vertically opposite each other.

4. The ultra-high frequency induction brazing device for the electromagnetic relay contact spring system according to claim 3, characterized in that: The first platform and the third platform are both provided with limit posts, and the fourth platform and the sixth platform have limit holes corresponding to the limit posts.

5. The ultra-high frequency induction brazing device for the electromagnetic relay contact spring system according to claim 3, characterized in that: The contact gap positioning plate also includes a base plate and a pressure plate; the lower surface of the base plate is correspondingly arranged with a fourth platform, a fifth platform and a sixth platform, the fifth platform has a cavity that runs vertically through it, the upper surfaces of the fourth platform and the sixth platform are both provided with limiting grooves, and the limiting grooves are connected to the cavity; one end of the contact gap insert is located in the limiting groove, and the other end extends into the cavity.

6. The ultra-high frequency induction brazing device for the electromagnetic relay contact spring system according to claim 5, characterized in that: The contact gap limiting insert includes a positioning section and an insertion section connected to each other; the positioning section is disposed in the limiting groove, and the insertion section extends into the cavity, the size of the insertion section corresponding to the required contact gap between the springs.

7. The ultra-high frequency induction brazing device for the electromagnetic relay contact spring system according to claim 1, characterized in that: The workbench has an opening on its surface for housing a moving mechanism, and the induction brazing head is mounted on the moving mechanism.

8. The ultra-high frequency induction brazing device for the electromagnetic relay contact spring system according to claim 1, characterized in that: The moving mechanism includes a base, a first slide rail assembly, a second slide rail assembly, a support base, and a locking assembly; the first slide rail assembly is disposed on the base, and the output end of the first slide rail assembly can reciprocate along a first direction; the second slide rail assembly is disposed on the output end of the first slide rail assembly, and the output end of the second slide rail assembly can reciprocate along a second direction; the support base is disposed on the output end of the second slide rail assembly; the locking assembly is fixed to the support base; and the locking assembly is used to fix the induction brazing head.

9. A method for ultra-high frequency induction brazing of an electromagnetic relay contact spring system, characterized in that: Includes the following steps: S1. Workpiece preparation: Roll the root of the spring sheet onto the corresponding Kovar alloy lead-out rod one by one to form a welding point between them; S2. Clamping: Fixing the workpiece with the welding point to be formed in place; S4. Place brazing filler metal: Place brazing filler metal at each point to be soldered; S5. Ultra-high frequency induction brazing: Move the induction brazing head so that the induction coil is facing one of the points to be welded, start the ultra-high frequency induction brazing machine, set the power parameters, and use a high-frequency alternating magnetic field to generate eddy currents on the surface of the Kovar alloy lead rod and the spring and heat them rapidly; during the heating process, the brazing filler melts and fully penetrates and fills the brazing gap between the spring and the Kovar alloy lead rod under capillary action. S6. Weld each weld point in sequence: After completing the welding of one weld point, turn off the induction heating power of the ultra-high frequency induction brazing machine; repeat step S3 until all weld points of a single product are welded in sequence. S7. Workpiece Cooling and Unloading: After all welding points are completed, allow the workpiece to cool naturally or with auxiliary cooling; remove the welded spring system components.

10. The ultra-high frequency induction brazing method for the electromagnetic relay contact spring system according to claim 9, characterized in that: The brazing gap is 0.08-0.10 mm.

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