Traveling wave tube slow wave structure welding die

Abstract

The embodiment of the present application discloses a kind of travelling wave tube slow wave structure welding mould, including the welding upper die and welding lower die of opposite arrangement;Positioning cylinder between the welding upper die and welding lower die;And the centering rod that passes through the welding upper die and welding lower die;The welding upper die and welding lower die are connected by screw rod and form welding support, two ends of the positioning cylinder are respectively with the welding upper die and welding lower die abut, the centering rod is located in the inner cavity of the positioning cylinder;To be welded slow wave structure is contained in the inner cavity of positioning cylinder, the centering rod includes first centering rod and second centering rod, the first centering rod is arranged in the electron beam passage of to be welded slow wave structure, and the second centering rod is arranged in the pin hole of to be welded slow wave structure.The improvement of slow wave structure degree, perpendicularity is realized, and the pipe body horizontal direction torsion is reduced, and the flow rate of further high-power travelling wave tube and yield rate are improved.

Description

Technical Field

[0001] This invention relates to the field of microwave vacuum electronics technology. More specifically, it relates to a welding mold for a traveling wave tube slow wave structure. Background Technology

[0002] A traveling wave tube (TWT) is a vacuum electronic device capable of generating or amplifying microwave signals, and it has broad development prospects in fields such as communications, electronic warfare, and radar systems. A TWT mainly consists of an electron gun, a slow-wave structure, a collector electrode, input / output devices, and a magnetic focusing system. The slow-wave structure is the site of beam-wave interaction, making it a key component for microwave signal generation or amplification. During operation, the high-current-density electron beam emitted by the electron gun needs to propagate within the electron beam channel of the slow-wave structure. In high-power TWTs, the coupling cavity and drift tube diameters are very small; if the electron beam channel deforms, electron trapping will occur within the slow-wave structure, resulting in poor electron beam focusing and affecting flux. Special attention must be paid to the alignment of the tube body during assembly, and precision brazing molds are used to ensure the stability of the slow-wave structure.

[0003] The brazing molds used in the prior art for high-power traveling wave tubes, such as Figure 1 As shown, this mold has the following disadvantages: First, the clamping of the slow wave structure is generally achieved by three to four screws driving the welding upper mold. The tightening force of the fastening nuts on different screws cannot be guaranteed to be completely consistent, which will cause the slow wave structure to deform, reduce the centering, and affect the flow. Second, the fastening nuts will rotate due to stress release in a high-temperature environment. The combined rotation of the fastening nuts on multiple screws will cause a slight displacement of the welding upper mold, which will cause the slow wave structure to twist, resulting in a shift in the waveguide direction and affecting subsequent assembly. Summary of the Invention

[0004] In view of the above problems, the purpose of this invention is to provide a welding mold for a traveling wave tube slow wave structure that can avoid deformation of the slow wave structure.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] A welding mold for a traveling wave tube slow wave structure, comprising:

[0007] The upper and lower welding molds are set relative to each other;

[0008] The positioning cylinder located between the upper welding mold and the lower welding mold; and

[0009] A centering rod that runs through the upper and lower welding dies;

[0010] The upper welding mold and the lower welding mold are connected by a screw to form a welding support. The two ends of the positioning cylinder abut against the upper welding mold and the lower welding mold respectively. The centering rod is located inside the cavity of the positioning cylinder.

[0011] The slow wave structure to be welded is housed within the inner cavity of the positioning cylinder. The centering rod includes a first centering rod and a second centering rod. The first centering rod passes through the electronic injection channel of the slow wave structure to be welded, and the second centering rod passes through the pin hole of the slow wave structure to be welded.

[0012] Furthermore, in a preferred embodiment, the welding mold includes multiple screws, which are evenly arranged around the periphery of the positioning cylinder;

[0013] The screw is connected to a fastening nut and a limiting nut at both ends. The fastening nut is located on the side of the upper welding mold away from the lower welding mold, and the limiting nut is located on the side of the lower welding mold away from the upper welding mold. The amount of screwing in of the fastening nut is adjusted to clamp the slow wave structure to be welded.

[0014] In addition, a preferred embodiment is that the contact end between the positioning cylinder and the welding upper mold is provided with a keyway, and the welding upper mold is provided with a corresponding limiting part, which is connected to the keyway in a corresponding manner.

[0015] Furthermore, in a preferred embodiment, the contact end between the positioning cylinder and the welding upper mold includes at least one keyway, the keyway being arranged circumferentially along the positioning cylinder.

[0016] Furthermore, in a preferred embodiment, the keyway and the limiting portion include a connection gap in the vertical direction.

[0017] Furthermore, in a preferred embodiment, the upper welding mold and the lower welding mold are provided with a first centering hole for the first pair of centering rods to pass through, and a second centering hole for the second pair of centering rods to pass through, wherein the second centering hole is evenly arranged around the circumference of the first centering hole.

[0018] Furthermore, in a preferred embodiment, the side of the lower welding mold closest to the upper welding mold includes a butt groove;

[0019] The docking groove is concentrically arranged with the first centering hole, the bottom of the positioning cylinder is installed in the docking groove, and the outer wall of the positioning cylinder abuts against the inner wall of the docking groove.

[0020] The mating groove includes an upwardly protruding pin, and the bottom of the positioning cylinder includes a pin hole that corresponds to and cooperates with the pin.

[0021] Furthermore, in a preferred embodiment, the welding mold further includes a pressing block.

[0022] Furthermore, a preferred embodiment is that the side wall of the positioning cylinder includes a weight-reducing hole that penetrates the side wall of the positioning cylinder.

[0023] Furthermore, a preferred embodiment is that the positioning cylinder is cylindrical, and the thermal expansion coefficient of the positioning cylinder is the same as or similar to that of the slow wave structure to be welded.

[0024] The beneficial effects of this invention are as follows:

[0025] This invention provides a welding mold for a traveling wave tube's slow-wave structure. Based on traditional slow-wave structure welding molds, improvements are made by incorporating a positioning cylinder between the upper and lower welding molds. This enhances the verticality and alignment of the slow-wave structure during welding, reduces horizontal displacement, and further improves its verticality. This effectively ensures stable continuous wave operation of the traveling wave tube and increases the yield rate. By providing keyways or limiting holes at both ends of the positioning cylinder, the amount of torsion of the slow-wave structure during welding can be conveniently and precisely controlled, eliminating excessive torsion of the fastening nut at high temperatures and ensuring consistency in subsequent assembly. Attached Figure Description

[0026] The specific embodiments of the present invention will be described in further detail below with reference to the accompanying drawings.

[0027] Figure 1 This diagram illustrates the assembly of a welding mold and a slow-wave structure in the prior art.

[0028] Figure 2 This diagram illustrates the assembly of the welding mold and the slow-wave structure provided in an embodiment of the present invention.

[0029] Figure 3 A schematic diagram of the positioning cylinder provided in an embodiment of the present invention is shown. Detailed Implementation

[0030] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, the accompanying drawings show only the parts relevant to the present invention, and not all of the structures.

[0031] In the description of this invention, unless otherwise explicitly specified and limited, the terms "connected," "linked," and "fixed" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two elements or the interaction between two elements. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0032] In this invention, unless otherwise expressly specified and limited, the first feature "above" or "below" the second feature may include direct contact between the first and second features, or contact between the first and second features not in direct contact but through another feature between them.

[0033] In the description of this embodiment, the terms "upper," "lower," "left," and "right," etc., refer to the orientation or positional relationship shown in the accompanying drawings. They are used only for ease of description and simplification of operation, 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 the present invention. In addition, the terms "first" and "second" are used only for distinction in description and have no special meaning.

[0034] The brazing molds used in the prior art for high-power traveling wave tubes, such as Figure 1 As shown, this mold has the following disadvantages: First, the verticality of the slow-wave structure depends on the lower welding mold 2 at the bottom, which is placed on the furnace bottom tray of the hydrogen furnace during welding. The furnace bottom tray serves as both a support and a material inlet / outlet for the hydrogen furnace, and is a movable part. After the hydrogen furnace body is closed, the horizontality of the welding mold placed on the furnace bottom tray cannot be guaranteed, nor can it be measured or adjusted. The slow-wave structure may tilt during welding, affecting its verticality. Second, the clamping of the slow-wave structure is generally achieved by three to four screws 4 driving the upper welding mold 1. The tightening force of the fastening nuts 5 on different screws 4 cannot be guaranteed to be completely consistent, which will cause deformation of the slow-wave structure, reduce centering, and affect flow. Third, the fastening nuts 5 will rotate due to stress release under high-temperature conditions. The combined rotation of the fastening nuts on multiple screws 4 will cause a slight displacement of the upper welding mold 1, which will cause the slow-wave structure to twist, resulting in a shift in the waveguide direction and affecting subsequent assembly.

[0035] To address the shortcomings of existing technologies, embodiments of the present invention provide a welding mold for a traveling wave tube slow wave structure, combined with... Figure 2-3 As shown, the welding mold includes an upper welding mold 1, a lower welding mold 2, a positioning cylinder 3, and a centering rod. The upper welding mold 1 and the lower welding mold 2 are connected by a screw 4 to form a welding support. The positioning cylinder 3 is located between the upper welding mold 1 and the lower welding mold 2, and its upper and lower ends abut against the upper welding mold 1 and the lower welding mold 2, respectively.

[0036] In one embodiment, the upper welding mold 1 and the lower welding mold 2 are connected by a screw 4. A fastening nut 5 and a limiting nut 6 are respectively connected to both ends of the screw 4. The fastening nut 5 is located on the side of the upper welding mold 1 opposite to the lower welding mold 2, and the limiting nut 6 is located on the side of the lower welding mold 2 opposite to the upper welding mold 1. Generally, the amount of screwing in the fastening nut 5 is changed to adjust the distance between the upper welding mold 1 and the lower welding mold 2, thereby clamping the slow-wave structure to be welded.

[0037] Specifically, the welding mold includes four screws 4, each screw 4 having a fastening nut 5 and a limiting nut 6 connected to both ends. The four screws 4 are evenly arranged around the periphery of the positioning cylinder 3 to ensure that the clamping force on different parts of the slow wave structure 100 to be welded is as uniform as possible. At the same time, the upper and lower ends of the positioning cylinder 3 abut against the upper welding mold 1 and the lower welding mold 2 respectively to ensure the parallelism and perpendicularity between the upper welding mold 1 and the lower welding mold 2, and to balance the clamping force on the slow wave structure 100 to be welded, avoiding excessive differences in preload force on different parts of the slow wave structure 100 that could lead to deformation of the slow wave structure.

[0038] In this embodiment, the positioning cylinder 3 is cylindrical, and the slow wave structure 100 to be welded and the centering rod are both housed within the inner cavity of the positioning cylinder 3. Specifically, the upper and lower ends of the positioning cylinder 3 abut against the upper welding mold 1 and the lower welding mold 2, respectively. The slow wave structure 100 to be welded is placed in the inner cavity of the positioning cylinder 3, located on the side surface of the lower welding mold 2 closest to the upper welding mold 1. The bottom surface of the upper welding mold 1 is pressed against the upper surface of the slow wave structure 100 to be welded. The slow wave structure 100 to be welded is clamped by adjusting the screwing amount of the fastening nut 5 for subsequent welding. The traveling wave tube slow wave structure has the characteristics of many parts and many welds, and there is a certain assembly gap between the parts. The presence of the positioning cylinder 3 limits the overall height of the slow wave structure 100 to be welded within a certain range, which can reduce the cumulative effect of the assembly tolerance between parts as the number of parts increases.

[0039] Furthermore, the centering rod penetrates the upper welding mold 1 and the lower welding mold 2. The centering rod is used to ensure the alignment of the pin hole 101 and the electron injection channel 102 of the slow wave structure 100 to be welded. The centering rod can slide freely within the upper welding mold 1 and the lower welding mold 2. During welding, the centering rod needs to be removed, and then the welding mold, together with the slow wave structure 100 to be welded inside the welding mold, is placed in the hydrogen furnace body for welding. The centering rod includes a first centering rod (not shown in the figure) and a second centering rod (not shown in the figure). The first centering rod is an electron injection channel centering rod, which is inserted into the electron injection channel 102 of the slow wave structure 100 to be welded. When the welding mold is clamped, the first centering rod needs to be able to slide freely within the electron injection channel 102 to ensure that the alignment of the electron injection channel 102 meets the requirements, thereby improving the stability of the slow wave structure 100, thus achieving stable operation of the traveling wave tube continuous wave and improving the yield. The second centering rod is a pin hole centering rod, which is inserted into the pin hole 101 of the slow wave structure 100 to be welded, and can slide freely in the pin hole 101 to ensure the centering of the pin hole 101 and improve the yield of the slow wave structure.

[0040] In one specific embodiment, the upper welding mold 1 and the lower welding mold 2 have a first centering hole 11 for the first centering rod to pass through, and a second centering hole 12 for the second centering rod to pass through. The second centering holes 12 are evenly arranged around the first centering holes 11 and correspond to the number and position of the pin holes 101 on the slow wave structure 100. In this embodiment, both the upper welding mold 1 and the lower welding mold 2 are circular plates. The first centering holes 11 are located at the center of the upper welding mold 1 and the lower welding mold 2 and are concentrically arranged with the upper welding mold 1 and the lower welding mold 2. The circumference of the multiple second centering holes 12 is located at the outer periphery of the first centering holes 11, and the circumference of the multiple screws 4 is located at the outer periphery of the circumference of the multiple second centering holes 12. When the slow wave structure 100 to be welded is placed into the hydrogen furnace, the first centering rod and the second centering rod need to be removed from the first centering holes 11 and the second centering holes 12 of the upper welding mold 1 or the lower welding mold 2.

[0041] In one embodiment, the lower welding mold 2 includes a mating groove 21 on its surface near the upper welding mold 1. The mating groove 21 is integrally formed with the first centering hole 11 and is concentrically arranged with the first centering hole 11. The positioning cylinder 3 is installed in the mating groove 21 to ensure the concentricity of the positioning cylinder 3 and the slow wave structure 100 to be welded. Specifically, the bottom edge of the positioning cylinder 3 is connected to the mating groove 21, and its outer wall abuts against the inner wall of the mating groove 21 to install the positioning cylinder 3 in the mating groove 21, restricting the displacement of the positioning cylinder 21 in the horizontal plane, thereby ensuring the verticality and centering of the slow wave structure 100 to be welded.

[0042] Furthermore, the docking groove 21 includes an upwardly protruding pin 22, and the bottom of the positioning cylinder 3 includes a pin hole 32 that corresponds to and cooperates with the pin 22. The pin 22 is installed in the pin hole 32 to position the positioning cylinder 3 and restrict the rotation of the positioning cylinder 3 around the central axis of the docking groove 21.

[0043] In a specific embodiment, such as Figure 2 As shown, a keyway 31 is provided at the contact end between the positioning cylinder 3 and the welding upper mold 1. The lower surface of the welding upper mold 1 includes a downwardly protruding limiting part 13, which is correspondingly engaged with the keyway 31. Since the relative position of the positioning cylinder 3 and the welding lower mold 2 is fixed, the connection between the limiting part 13 and the keyway 31 can limit the welding upper mold 1. When the stress of the fastening nut 5 is released under high temperature, the welding upper mold 1 will not shift, thus preventing the torsion of the slow wave structure 100 to be welded, avoiding the deviation of the waveguide direction, improving the centering accuracy, ensuring subsequent assembly, and improving the yield of the traveling wave tube. In addition, the machining accuracy and structural strength of the positioning cylinder 3 itself ensure the concentricity and perpendicularity of its inner wall surface relative to the welding lower mold 2, eliminating the influence of poor bottom levelness.

[0044] When the slow-wave structure 100 to be welded is clamped by rotating the fastening nuts 5 of multiple screws 4, the mating relationship between the keyway 31 and the limiting part 13 restricts the tilting and offset of the welding upper mold 1, avoiding the influence of inconsistent tightening forces of the fastening nuts 5 on different screws 4 on the deformation of the slow-wave structure 100, ensuring the centering of the slow-wave structure 100, thereby improving the yield. It should be noted that the contact end between the positioning cylinder 3 and the welding upper mold 1 includes at least one keyway 31, which is arranged circumferentially along the positioning cylinder 3 to limit the displacement of the welding upper mold 1 relative to the positioning cylinder 3. In this embodiment, the limiting part 13 is a connecting key; in other embodiments, the keyway 31 can be in the form of a pin hole, in which case the limiting part 13 is a pin structure.

[0045] During the welding process, the overall height of the slow wave structure 100 will change after the solder melts. In one embodiment, the keyway 31 and the limiting part 13 include a connection gap in the vertical direction. This connection gap can buffer when the overall height of the slow wave structure 100 changes, so that the welding upper mold 1 always presses the slow wave structure 100 tightly and ensures the welding quality.

[0046] In one embodiment, the welding mold further includes a pressure block 8, which is placed on the upper surface of the upper welding mold 1. The upper surface of the upper welding mold 1 includes a groove for placing the pressure block 8. The pressure block 8 can provide continuous clamping force to the slow wave structure 100 to be welded when the clamping force of the fastening nut 5 decreases due to high temperature. Furthermore, the center of the pressure block 8 includes a third centering hole 80 communicating with the first centering hole for the first centering rod to pass through.

[0047] In one embodiment, the side wall of the positioning cylinder 3 is provided with a plurality of weight-reducing holes 33 that penetrate the side wall surface.

[0048] In one embodiment, the thermal expansion coefficient of the positioning cylinder 3 in the high-temperature chamber is the same as or similar to that of the slow wave structure 100 to be welded, which can ensure consistency with the slow wave structure 100 to be welded.

[0049] This invention provides a welding mold for a traveling wave tube's slow-wave structure. Based on traditional slow-wave structure welding molds, improvements are made by incorporating a positioning cylinder between the upper and lower welding molds. This enhances the verticality and alignment of the slow-wave structure during welding, reduces horizontal displacement, and further improves its stability. This results in stable continuous wave operation of the traveling wave tube and increases the yield rate. Furthermore, by providing keyways or limiting holes at both ends of the positioning cylinder, the amount of torsion of the slow-wave structure during welding can be conveniently and precisely controlled, eliminating excessive torsion of the fastening nut at high temperatures and ensuring consistency in subsequent assembly.

[0050] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the implementation of the present invention. For those skilled in the art, other variations or modifications can be made based on the above description. It is impossible to exhaustively list all the implementation methods here. All obvious variations or modifications derived from the technical solutions of the present invention are still within the protection scope of the present invention.

Claims

1. A welding mold for a traveling wave tube slow wave structure, characterized in that, include: The upper and lower welding molds are set relative to each other; The positioning cylinder is located between the upper welding mold and the lower welding mold; as well as A centering rod that runs through the upper and lower welding dies; The upper welding mold and the lower welding mold are connected by a screw to form a welding support. The two ends of the positioning cylinder abut against the upper welding mold and the lower welding mold respectively. The centering rod is located inside the cavity of the positioning cylinder. The slow wave structure to be welded is housed in the inner cavity of the positioning cylinder. The centering rod includes a first centering rod and a second centering rod. The first centering rod passes through the electronic injection channel of the slow wave structure to be welded, and the second centering rod passes through the pin hole of the slow wave structure to be welded. The positioning cylinder has a keyway at the contact end with the welding upper mold, and the welding upper mold has a corresponding limiting part, which is connected to the keyway. The lower welding mold includes a butt groove on the side near the upper welding mold; the bottom of the positioning cylinder is installed in the butt groove, and the outer wall of the positioning cylinder abuts against the inner wall of the butt groove; the butt groove includes an upwardly protruding pin, and the bottom of the positioning cylinder includes a pin hole corresponding to and cooperating with the pin.

2. The welding mold for the slow-wave structure of a traveling wave tube according to claim 1, characterized in that, The welding mold includes multiple screws, which are evenly arranged around the periphery of the positioning cylinder; The screw is connected to a fastening nut and a limiting nut at both ends. The fastening nut is located on the side of the upper welding mold away from the lower welding mold, and the limiting nut is located on the side of the lower welding mold away from the upper welding mold. The amount of screwing in of the fastening nut is adjusted to clamp the slow wave structure to be welded.

3. The welding mold for the slow-wave structure of a traveling wave tube according to claim 1, characterized in that, The contact end between the positioning cylinder and the welding upper mold includes at least one keyway, which is arranged along the circumference of the positioning cylinder.

4. The welding mold for the slow-wave structure of a traveling wave tube according to claim 1, characterized in that, The keyway and the limiting part include a connection gap in the vertical direction.

5. The welding mold for the slow-wave structure of a traveling wave tube according to claim 1, characterized in that, The upper and lower welding molds are provided with a first centering hole for the first pair of centering rods to pass through, and a second centering hole for the second pair of centering rods to pass through. The second centering holes are evenly arranged around the circumference of the first centering holes.

6. The welding mold for the slow-wave structure of a traveling wave tube according to claim 5, characterized in that, The docking groove is concentrically arranged with the first centering hole.

7. The welding mold for the slow-wave structure of a traveling wave tube according to claim 1, characterized in that, The welding mold also includes a pressing block.

8. The welding mold for the slow-wave structure of a traveling wave tube according to claim 1, characterized in that, The side wall of the positioning cylinder includes a weight-reducing hole that penetrates the side wall of the positioning cylinder.

9. The welding mold for the slow-wave structure of a traveling wave tube according to claim 1, characterized in that, The positioning cylinder is cylindrical, and its thermal expansion coefficient is the same as or similar to that of the slow-wave structure to be welded.

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