Positioning fixture for brazing of a magnetron anode assembly

Abstract

This invention discloses a positioning fixture for brazing magnetron anode assemblies, relating to the field of magnetron anode assembly technology. It addresses the problems of insufficient multi-dimensional positioning of anode blades, low positioning accuracy of the coupling antenna, and uneven force during disassembly, which can easily damage parts. Its main structure includes: a barrel-shaped base located below the anode cylinder; a liftable blade indexing base within the opening of the barrel-shaped base; a blade indexing guide post and a blade indexing guide groove on the upper surface of the blade indexing base; and a radially expandable central expansion component at the axis. A coupling antenna positioning barrel is located above the anode cylinder, with a coupling antenna positioning groove at the axis of its upper surface. This invention achieves precise axial, radial, and circumferential positioning of the anode blades and central positioning of the coupling antenna. After brazing, rapid and non-destructive disassembly is achieved through the smooth descent of the blade indexing base, effectively improving brazing accuracy and production efficiency.

Description

Technical Field

[0001] This invention relates to the field of magnetron anode assembly technology, and in particular to a positioning fixture for brazing magnetron anode assemblies. Background Technology

[0002] High-power continuous-wave magnetrons have broad application prospects in fields such as industrial heating and plasma research. For example... Figure 4 As shown, the magnetron anode assembly consists of an anode cylinder 6, anode blades 7, a diaphragm strip 8, and a coupling antenna 9, which require a reliable connection through a high-temperature brazing process in a furnace. During the brazing process, the magnetron anode assembly must use a special fixture to clamp and position each component to ensure that the relative positions of the components remain unchanged during heating and cooling. Therefore, the brazing of the magnetron anode assembly requires extremely high precision in fixture positioning, prevention of solder adhesion, and ease of disassembly.

[0003] However, existing magnetron anode assembly brazing fixtures generally have the following significant drawbacks: 1. Existing fixtures mostly employ positioning methods such as slotted anode cylinders or upper and lower clamps with a center pin, which can only achieve simple radial or axial constraints, severely lacking in multi-dimensional limiting of the anode blades in the axial, radial, and circumferential directions. During the welding process, the anode blades are prone to radial movement and circumferential deflection, causing deviations in the dimensional accuracy of the resonant cavity. At the same time, for slender rod-shaped coupled antennas, existing fixtures lack effective centering measures, making the antennas highly susceptible to eccentricity and tilting, directly affecting the microwave output efficiency and operational stability of the magnetron.

[0004] 2. Existing fixtures, when subjected to forced separation, often rely on hammering or prying due to the lack of a stable guiding disassembly mechanism. This uneven disassembly force makes the fixture prone to tilting. This not only squeezes and deforms the anode blades but also scratches the blade surface, leading to increased high-frequency losses, reduced magnetron operating stability and lifespan, and difficulty in guaranteeing product qualification rates.

[0005] In summary, there is an urgent need to develop a high-precision quick-release magnetron anode assembly brazing fixture that can achieve multi-dimensional precise positioning of the anode blades and coupled antennas, and can be smoothly, quickly and without damage disassembly. Summary of the Invention

[0006] The purpose of this invention is to provide a positioning fixture for brazing a magnetron anode assembly. Through the coordinated operation of the coupling antenna positioning barrel, the blade indexing base and the central expansion component, it can achieve multi-dimensional precise positioning of the anode blade in the axial, radial and circumferential directions and the center positioning of the coupling antenna. At the same time, the liftable blade indexing base can realize the smooth, fast and non-destructive disassembly of the fixture and the anode assembly after brazing.

[0007] The technical solution of this invention to solve the above-mentioned technical problems is: a positioning fixture for brazing a magnetron anode assembly, comprising a barrel-shaped base coaxially disposed below the anode cylinder with its opening vertically upward; a blade indexing base coaxially disposed within the opening of the barrel-shaped base, which is liftable and has its outer wall transitionally fitted with the inner wall of the anode cylinder; a plurality of blade indexing guide posts are provided on the upper end face of the blade indexing base, which are evenly arranged around its axis and do not contact the inner wall of the anode cylinder; a blade indexing guide groove for positioning and clamping anode blades is provided between adjacent blade indexing guide posts; a central expansion assembly is provided at the axis of the upper end face of the blade indexing base, which can be inserted axially into a central hole formed by multiple anode blades and can expand radially to abut the anode blades against the inner wall of the anode cylinder; It also includes a coupling antenna positioning barrel coaxially positioned above the anode cylinder with its opening vertically downward. The lower outer wall of the coupling antenna positioning barrel transitions with the inner wall of the anode cylinder, and the lower end face of the coupling antenna positioning barrel abuts against the upper surface of the anode blade. The upper end face of the coupling antenna positioning barrel is provided with a coupling antenna positioning groove at the center of the axis for the upper part of the coupling antenna to pass through and transition with it.

[0008] As a further improvement of the present invention, the opening of the barrel-shaped base is provided with a lifting drive assembly for driving the blade indexing base to rise and fall.

[0009] As a further improvement of the present invention, the lifting drive assembly includes a pull rod coaxially arranged with the barrel-shaped base. The upper end of the pull rod is rotatably connected to the lower end face of the blade indexing base, and the lower end of the pull rod passes through the lower surface of the barrel-shaped base. The two are threadedly connected.

[0010] As a further improvement of the present invention, a fixing plate is sleeved on the upper part of the pull rod with clearance fitting thereto, and the fixing plate is fixedly connected to the lower end face of the blade indexing base by screws. An anti-detachment part is provided on the outer wall of the pull rod between the fixing plate and the blade indexing base.

[0011] As a further improvement of the present invention, a drive rod is detachably and horizontally inserted into the pull rod body located below the barrel-shaped base.

[0012] As a further improvement of the present invention, the central expansion assembly includes a vertically arranged elastic expansion core with an axial through opening, and a top core is detachably inserted into the axial through opening of the elastic expansion core.

[0013] As a further improvement of the present invention, the top core is a frustum-shaped structure with a cross-sectional area that gradually decreases from top to bottom, and the inner wall of the elastic expansion core and the outer wall of the top core are in a conical extrusion fit.

[0014] As a further improvement of the present invention, the distance between the outer wall of the blade indexing guide post and the inner wall of the anode cylinder is 0.5mm-1mm.

[0015] As a further improvement of the present invention, a protrusion for supporting the diaphragm belt is provided on the upper surface of the blade indexing base between the blade indexing guide post and the central expansion assembly.

[0016] As a further improvement of the present invention, all components in contact with the anode assembly are made of blackened stainless steel.

[0017] Beneficial effects Compared with the prior art, the advantages of the positioning fixture for brazing magnetron anode assemblies of the present invention are as follows: 1. The anode blade is circumferentially limited by the blade indexing guide groove, and the anode blade is radially positioned by the central expansion component pressing it against the inner wall of the anode cylinder. The lower end face of the coupling antenna positioning barrel cooperates with the upper end face of the blade indexing base to axially limit the anode blade. At the same time, the coupling antenna positioning groove centers the coupling antenna. This achieves all-round limiting of the anode blade in the axial, radial and circumferential directions and precise positioning of the coupling antenna. It effectively avoids radial movement and circumferential deflection of the anode blade and eccentric tilt of the coupling antenna during the brazing process, and significantly improves the brazing accuracy and product consistency of the anode assembly. 2. After brazing, the blade indexing base is smoothly lowered by the lifting drive assembly, causing the fixture to separate from the anode assembly in a straight axial direction. During the disassembly process, the blade indexing base remains horizontal, and the disassembly force is even. This completely avoids the problems of fixture tilting, squeezing deformation, or scratching the anode blade surface caused by uneven force due to traditional hammering or prying methods. This ensures the indexing accuracy and surface quality of the anode blade, while significantly shortening the disassembly time and significantly improving production efficiency.

[0018] The invention will become clearer from the following description, taken in conjunction with the accompanying drawings, which are used to explain embodiments of the invention. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 This is a schematic diagram of the internal structure of the present invention; Figure 2 This is an exploded view of the present invention along its axial direction; Figure 3 This is a diagram showing the usage state of the present invention; Figure 4 This is a schematic diagram of the anode assembly.

[0021] Wherein: 1-Coupled antenna positioning barrel; 11-Coupled antenna positioning slot; 2-Blade indexing base; 21-Blade indexing guide slot; 22-Blade indexing guide post; 3-Barrel-shaped base; 4-Pull rod; 41-Anti-detachment part; 42-Fixing plate; 43-Screw; 44-Drive rod; 5-Elastic expansion core; 51-Top core; 6-Anode cylinder; 7-Anode blade; 8-Diaphragm belt; 9-Coupled antenna. Detailed Implementation

[0022] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings. Obviously, the described embodiments are merely some embodiments of this invention, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0023] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; of course, they can also refer to a mechanical connection or an electrical connection; furthermore, they can refer to a direct connection, an indirect connection through an intermediate medium, or a connection within two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0024] Embodiments of the present invention will now be described with reference to the accompanying drawings.

[0025] Example: Specific embodiments of the present invention are as follows: Figure 1-3 As shown, a positioning fixture for brazing a magnetron anode assembly includes a barrel-shaped base 3 coaxially positioned below the anode cylinder 6 with its opening vertically upward. A blade indexing base 2, capable of being raised and lowered, with its outer wall transitionally fitted to the inner wall of the anode cylinder 6, is coaxially disposed within the opening of the barrel-shaped base 3. The blade indexing base 2, through the transitional fit between its outer wall and the inner wall of the anode cylinder 6, achieves radial positioning of the anode cylinder 6, ensuring the coaxiality of the anode cylinder 6 and the fixture as a whole.

[0026] The blade indexing base 2 has multiple blade indexing guide posts 22 evenly arranged around its axis and not in contact with the inner wall of the anode cylinder 6 on its upper surface. Adjacent blade indexing guide posts 22 are connected by blade indexing guide grooves 21 for positioning and mounting the anode blades 7. During anode assembly, the lower part of each anode blade 7 is inserted into its corresponding blade indexing guide groove 21. The groove wall of the blade indexing guide groove 21 provides circumferential constraint to each anode blade 7, effectively preventing circumferential deflection of the anode blades 7 during brazing and ensuring the indexing accuracy of the anode blades 7. Furthermore, the outer wall of the blade indexing guide post 22 is not in contact with the inner wall of the anode cylinder 6—in this embodiment, the preferred distance between them is 0.5mm-1mm. This gap forms an annular space during brazing to accommodate excess flowing solder, preventing solder accumulation between the blade indexing guide post 22 and the inner wall of the anode cylinder 6.

[0027] To achieve radial positioning of the anode blades 7, a central expansion assembly is provided at the center of the upper end face of the blade indexing base 2. This assembly can be inserted axially into a central hole formed by multiple anode blades 7 and can expand radially to bring the anode blades 7 into contact with the inner wall of the anode cylinder 6. Specifically: The central expansion assembly specifically includes a vertically arranged elastic expansion core 5 with an axially penetrating opening, into which a top core 51 is detachably inserted. In this embodiment, the top core 51 is a frustum-shaped structure with a cross-sectional area gradually decreasing from top to bottom, and the inner wall of the elastic expansion core 5 and the outer wall of the top core 51 are fitted with a conical extrusion fit. In use, the elastic expansion core 5 is first inserted into the central hole formed by the anode blades 7, and then the top core 51 is inserted into the inner hole of the elastic expansion core 5 and pressed downward. The conical surface of the top core 51 slides down along the inner wall of the elastic expansion core 5, forcing the elastic expansion core 5 to expand uniformly outward in the radial direction, uniformly pressing each anode blade 7 against the inner wall of the anode cylinder 6, thereby achieving precise radial positioning of the anode blades 7. In addition, the upper surface of the blade indexing base 2 between the blade indexing guide post 22 and the central expansion assembly is also provided with a protrusion for supporting the diaphragm belt 8. Before brazing, the diaphragm belt 8 located below the anode assembly is placed on this protrusion for axial positioning.

[0028] Furthermore, the positioning fixture also includes a coupling antenna positioning barrel 1 coaxially positioned above the anode cylinder 6 with its opening vertically downwards. The lower outer wall of the coupling antenna positioning barrel 1 transitions into the inner wall of the anode cylinder 6, and the lower end face of the coupling antenna positioning barrel 1 abuts against the upper surface of the anode blade 7. A coupling antenna positioning groove 11 is provided at the axial center of the upper end face of the coupling antenna positioning barrel 1, through which the upper part of the coupling antenna 9 passes and transitions into it. During assembly, the lower end face of the coupling antenna positioning barrel 1 and the upper end face of the blade indexing base 2 abut against the upper and lower surfaces of the anode blade 7, respectively, forming an axial clamping of the anode blade 7 and achieving axial positioning of the anode blade 7. The upper end of the coupling antenna 9 is inserted into the coupling antenna positioning groove 11, and the transitional fit between the two enables precise center positioning of the coupling antenna 9, preventing the coupling antenna 9 from being eccentric or tilted.

[0029] In addition, to enable rapid and non-destructive disassembly after brazing, a lifting drive assembly for driving the blade indexing base 2 to rise and fall is provided inside the opening of the barrel-shaped base 3. This lifting drive assembly includes a pull rod 4 coaxially arranged with the barrel-shaped base 3. The upper end of the pull rod 4 is rotatably connected to the lower end face of the blade indexing base 2. Specifically, a fixing plate 42 with clearance fit is sleeved on the upper part of the pull rod 4. The fixing plate 42 is fixedly connected to the lower end face of the blade indexing base 2 by screws 43. An anti-detachment part 41 is provided on the outer wall of the pull rod 4 between the fixing plate 42 and the blade indexing base 2, allowing the pull rod 4 to rotate freely relative to the blade indexing base 2 without detaching. The lower end of the pull rod 4 passes through the lower surface of the barrel-shaped base 3, and the two are threadedly connected. A drive rod 44 is detachably and horizontally inserted into the pull rod 4 located below the barrel-shaped base 3.

[0030] After brazing, the drive rod 44 is inserted into the pull rod 4. Rotating the drive rod 44 causes the pull rod 4 to rotate. Through the threaded engagement between the pull rod 4 and the barrel-shaped base 3, the pull rod 4 moves smoothly downward, thereby pulling the blade indexing base 2 down smoothly along the axial direction, achieving a linear separation between the blade indexing base 2 and the anode assembly. Throughout the disassembly process, the blade indexing base 2 remains horizontal, and the disassembly force is balanced, completely avoiding the problems of uneven force distribution that cause the clamp to tilt, be squeezed and deformed, or scratch the surface of the anode blade 7 due to traditional hammering or prying methods.

[0031] It is important to note that: To prevent solder adhesion, all components in contact with the anode assembly are made of blackened stainless steel. The blackening process forms a dense oxide film on the stainless steel surface, effectively preventing the molten solder from wetting and spreading on the fixture surface during brazing, further ensuring smooth disassembly. Simultaneously, the diaphragm belt 8 itself has a silver plating layer, which acts as the solder itself; therefore, no solder needs to be placed on the contact surface between the diaphragm belt 8 and the anode blade 7. Furthermore, solder is only placed on the end of the anode blade 7 that contacts the inner wall of the anode cylinder 6 on its upper surface.

[0032] The present invention has been described above in conjunction with the preferred embodiments, but the present invention is not limited to the embodiments disclosed above, but should cover various modifications and equivalent combinations made in accordance with the essence of the present invention.

Claims

1. A positioning fixture for brazing a magnetron anode assembly, characterized in that, The system includes a barrel-shaped base (3) coaxially positioned below the anode cylinder (6) with its opening facing vertically upwards. Inside the opening of the barrel-shaped base (3) is a blade indexing base (2) that can be raised and lowered and whose outer wall transitions with the inner wall of the anode cylinder (6). The upper end face of the blade indexing base (2) is provided with multiple blade indexing guide posts (22) evenly arranged around its axis and not in contact with the inner wall of the anode cylinder (6). Between adjacent blade indexing guide posts (22) is a blade indexing guide groove (21) for positioning and clamping the anode blades (7). At the axis of the upper end face of the blade indexing base (2), there is a central expansion assembly that can be inserted into the central hole formed by multiple anode blades (7) along its axial direction and can expand along its radial direction to make the anode blades (7) abut against the inner wall of the anode cylinder (6). It also includes a coupling antenna positioning barrel (1) coaxially positioned above the anode cylinder (6) with its opening facing vertically downward. The lower outer wall of the coupling antenna positioning barrel (1) transitions with the inner wall of the anode cylinder (6), and the lower end face of the coupling antenna positioning barrel (1) abuts against the upper surface of the anode blade (7). The upper end face of the coupling antenna positioning barrel (1) is provided with a coupling antenna positioning groove (11) at the center of the axis for the upper part of the coupling antenna (9) to pass through and transition with it.

2. The positioning fixture for brazing magnetron anode assemblies according to claim 1, characterized in that, The opening of the barrel-shaped base (3) is provided with a lifting drive assembly for driving the blade indexing base (2) to rise and fall.

3. The positioning fixture for brazing magnetron anode assemblies according to claim 2, characterized in that, The lifting drive assembly includes a pull rod (4) coaxially arranged with the barrel base (3). The upper end of the pull rod (4) is rotatably connected to the lower end face of the blade indexing base (2). The lower end of the pull rod (4) passes through the lower surface of the barrel base (3), and the two are threadedly connected.

4. The positioning fixture for brazing magnetron anode assemblies according to claim 3, characterized in that, The upper part of the pull rod (4) is fitted with a fixing plate (42) that is clearance-fitted with it, and the fixing plate (42) is fixedly connected to the lower end face of the blade indexing base (2) by screws (43). The outer wall of the pull rod (4) between the fixing plate (42) and the blade indexing base (2) is provided with an anti-detachment part (41).

5. The positioning fixture for brazing magnetron anode assemblies according to claim 3, characterized in that, A drive rod (44) is detachably and horizontally inserted into the rod body of the pull rod (4) located below the barrel base (3).

6. The positioning fixture for brazing magnetron anode assemblies according to claim 1, characterized in that, The central expansion assembly includes a vertically arranged elastic expansion core (5) with an axial through opening, and a top core (51) is detachably inserted into the axial through opening of the elastic expansion core (5).

7. The positioning fixture for brazing magnetron anode assemblies according to claim 6, characterized in that, The top core (51) is a frustum-shaped structure with a cross-sectional area that gradually decreases from top to bottom, and the inner wall of the elastic expansion core (5) and the outer wall of the top core (51) are in a conical extrusion fit.

8. The positioning fixture for brazing magnetron anode assemblies according to claim 1, characterized in that, The distance between the outer wall of the blade indexing guide post (22) and the inner wall of the anode cylinder (6) is 0.5mm-1mm.

9. The positioning fixture for brazing magnetron anode assemblies according to claim 1, characterized in that, The upper surface of the blade indexing base (2) between the blade indexing guide post (22) and the central expansion assembly is provided with a protrusion for supporting the diaphragm belt (8).

10. The positioning fixture for brazing a magnetron anode assembly according to any one of claims 1 to 9, characterized in that, All components in contact with the anode assembly are made of blackened stainless steel.

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