Large aperture soft waveguide and method of manufacturing the same

Abstract

The application discloses a large-diameter soft waveguide and a preparation method thereof, and comprises the following steps: S1: adopting a stamping processing technology, a metal plate is processed into a corrugated plate which is wavelike along the length direction and the corrugation extends along the width direction; the corrugated plate is formed by stamping a metal plate strip, and then a waveguide tube body is prepared through bending and tailor welding, so that the dependence on large-diameter integrally-formed thin-wall seamless copper pipes is completely got rid of, and the problems of great forming difficulty of raw materials, low yield, high cost and uncontrollable supply cycle in the traditional process are fundamentally solved; especially when an aluminum strip or an aluminum alloy strip is used as the raw material, compared with the same-specification large-diameter thin-wall seamless copper pipe, the material cost can be reduced by about 95%, and the raw material supply is stable, so that the large-batch production is suitable.

Description

Technical Field

[0001] This invention relates to the field of communication technology, and in particular to a large-aperture soft waveguide and its fabrication method. Background Technology

[0002] In millimeter-wave communication, radar, and testing systems, flexible waveguides are often used for flexible connections between devices to accommodate installation errors and relative motion. In recent years, the rapid development of large-scale scientific facilities has increased the demand for large-diameter flexible waveguides. However, current manufacturing processes still use methods for small-diameter flexible waveguides, relying on integrally molded thin-walled seamless tubes as the core raw material. Furthermore, producing large-diameter flexible waveguides using the same principles as small-diameter waveguides requires scaling up equipment to meet production demands, which raises a series of problems: Raw materials for production: Large-diameter one-piece molded thin-walled seamless copper tubes, which are extremely difficult to produce and have a very low yield rate, resulting in high costs and an extremely uncontrollable production cycle. Production equipment: The waveguides used in the communications field are basically rectangular in shape, but there is no standard equipment for producing rectangular corrugated pipes on the market. In order to meet production needs, we can only customize production equipment. Compared with the production equipment for small-diameter flexible waveguides, the cost of custom production equipment for large-diameter flexible waveguides increases exponentially. Molding molds: The cost of a set of small-diameter molding molds is usually several thousand yuan, while the purchase price of a set of large-diameter molding molds is around 30,000 to 80,000 yuan. The mold opening cost is high and they are not universal. Product overweight: Current production methods can only use copper tubes as raw materials, and it is difficult to integrally form thin-walled seamless tubes. Usually, the wall thickness is increased to reduce the production difficulty, but this will also increase the product weight and add meaningless dead weight. The aforementioned defects have become the main bottlenecks restricting its widespread application and mass production. Currently, the market urgently needs a preparation method that can achieve low cost, large-scale production, and high yield. Summary of the Invention

[0003] To address the shortcomings of existing technologies, this invention provides the following technical solution: On the one hand, a method for fabricating a large-aperture soft waveguide is provided, including the following steps: S1: The metal sheet is processed into a corrugated sheet with a wavy undulation along its length and the corrugations extending along its width using a stamping process. S2: Bend the corrugated plate into a C-shaped structure with an opening, so that the corrugations extend circumferentially along the cross-section of the C-shaped structure. Take two C-shaped structures formed by bending the corrugated plate and stack them facing each other with their openings opposite each other to form a tubular body with a closed-loop corrugated cross-section. S3: Weld the overlapping areas of the two corrugated plates with the C-shaped structure to obtain a corrugated pipe body; S4: Install flanges at both ends of the bellows body.

[0004] As an improvement to the above technical solution, the metal sheet in step S1 is an aluminum strip or aluminum alloy strip, the material state is O, and the wall thickness is 0.3mm to 1.5mm.

[0005] As an improvement to the above technical solution, in step S2, a bending fixture is used to bend the corrugated plate into the C-shaped structure, and the corrugation extension direction of the corrugated plate extends circumferentially along the cross-section of the corrugated pipe.

[0006] As an improvement to the above technical solution, in step S1, the width of the metal plate is determined according to the perimeter of the target rectangular waveguide. The width of each metal plate is the sum of half the perimeter of the cross section and the overlap amount. The perimeter of the cross section formed by the splicing of two C-shaped corrugated plates is equal to the perimeter of the target rectangular waveguide.

[0007] As an improvement to the above technical solution, the wave-shaped ripples formed by stamping in step S1 are sinusoidal waveforms, trapezoidal waveforms, or sawtooth waveforms.

[0008] As an improvement to the above technical solution, in step S4, laser welding is used to weld the flange to the end of the bellows body.

[0009] As an improvement to the above technical solution, in step S4, the corrugated pipe body is connected to the flange by screws.

[0010] On the other hand, a large-diameter flexible waveguide is provided, which is prepared by the aforementioned method. The large-diameter flexible waveguide includes: a corrugated tube body consisting of two stamped C-shaped corrugated plates stacked and welded together with their sidewall edges overlapping each other, and flanges respectively disposed at both ends of the corrugated tube body.

[0011] The beneficial effects of this invention are: By using stamped metal strips to form corrugated plates, and then bending and welding them to form waveguide bodies, the reliance on large-diameter one-piece thin-walled seamless copper tubes is completely eliminated. This fundamentally solves the problems of difficult raw material forming, low yield, high cost, and uncontrollable supply cycle in traditional processes. In particular, when using aluminum strips or aluminum alloy strips as raw materials, the material cost can be reduced by about 95% compared with large-diameter thin-walled seamless copper tubes of the same specifications, and the raw material supply is stable, making it suitable for mass production. This invention requires only one set of stamping dies to produce corrugated plates with different cross-sectional sizes. By cutting metal plates of different widths and adjusting the bending fixtures accordingly, it can be compatible with multiple waveguide models without the need to open a separate forming die for each waveguide model, which greatly reduces the investment in dies and the cost of product changeover. When two C-shaped corrugated plates are joined together with their openings facing each other, their sidewall edges overlap, forming an overlapping area. This facilitates splicing positioning and pre-fixation, and significantly increases the welding contact area, which is beneficial for improving weld strength and sealing reliability. Especially when ultrasonic welding is used, the heat-affected zone is small, the base material properties are well maintained, and the weld is uniform and dense, meeting the airtightness and mechanical strength requirements of large-diameter soft waveguides. Attached Figure Description

[0012] Figure 1 This is a schematic diagram of the corrugated plate structure formed by stamping in an embodiment of the present invention; Figure 2 This is a schematic diagram of the C-shaped corrugated plate formed after the corrugated plate is bent in an embodiment of the present invention; Figure 3 This is a schematic diagram of the corrugated pipe structure formed by stacking and splicing two C-shaped corrugated plates facing each other in an embodiment of the present invention. Figure 4 This is a schematic diagram of the overall structure of the large-aperture soft waveguide of the present invention.

[0013] The markings in the diagram are as follows: 1-Corrugated plate; 2-C-shaped corrugated plate; 3-Corrugated pipe body. Detailed Implementation

[0014] 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 and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0015] Compared to traditional solutions, this solution has obvious advantages. In terms of versatility, one mold can be compatible with multiple models, eliminating the need to open molds for each model and pay high mold opening fees. It also eliminates the need to spend high prices to purchase thin-walled seamless tubes of the corresponding size for each model. To produce a corrugated tube of the same model and length, the price of aluminum strip is reduced by nearly 95% compared to large-diameter one-piece molded thin-walled seamless copper tubes, which greatly saves material costs. In terms of equipment, conventional stamping machinery can be used, without the need to find equipment manufacturers to customize special equipment. On the one hand, the development difficulty is reduced and the equipment procurement cost is reduced. On the other hand, the maintenance cost of the equipment is also greatly reduced by using conventional stamping machinery. Traditional corrugated forming dies consist of five parts: a front die plate, a rear die plate, a forming head, a guide box, and a mandrel. Each of the front and rear die plates is further divided into upper and lower dies. The dies are complex and costly. Due to the large diameter, the dies are bulky and heavy, requiring a crane for installation. This places demands on the site and supporting facilities. Each time a die is changed, the position and parallelism between each die need to be calibrated; otherwise, the produced corrugated pipes will be defective. In contrast, the stamping solution only requires a pair of upper and lower dies in reciprocating motion to achieve the corrugated forming function, resulting in significantly lower installation complexity and site requirements. In terms of weight, aluminum alloy, as a raw material, has a natural weight advantage compared to the traditional copper material. Compared to copper, aluminum alloy reduces weight by nearly 70%, which also increases the convenience of installation and transportation.

[0016] Example 1

[0017] Step S1: Stamping corrugated sheet 1060 aluminum strip is selected as the metal sheet, the material state is O state (fully annealed state), the aluminum strip thickness is 0.5mm, and the aluminum strip width is 671mm, which includes half of the cross-sectional perimeter and the overlap. The cut aluminum strip is fed into a stamping machine, which is a commercially available ordinary mechanical or hydraulic stamping press. The stamping die includes an upper die and a lower die. The opposing surfaces of the upper and lower dies are respectively provided with intermeshing wave-shaped tooth sets. The tooth shape is a sinusoidal waveform. During stamping, the aluminum strip is placed between the upper and lower dies. Through the reciprocating motion of the die, corrugated plates 1 are continuously stamped onto the aluminum strip. Figure 1 As shown, during stamping, the corrugations are formed along the width direction of the aluminum strip (the corrugation ridges are along the width direction), that is, the aluminum strip undulates in a wave shape along the length direction. During the stamping process, the pitch and depth of the corrugations can be controlled by adjusting the stroke of the punch press and the feeding pitch. Using the same set of stamping dies, corrugated plates of corresponding widths can be stamped simply by changing the aluminum strips of different widths. Therefore, the stamping die has good versatility for different waveguide models.

[0018] Step S2: Bend into a C-shaped structure The corrugated plate 1 obtained in step S1 is bent using a bending fixture. This bending fixture includes a supporting mandrel that matches the corrugated shape of the plate and a movable bending die. The corrugated plate 1 is placed on the supporting mandrel, with the length direction of the plate aligned with the mandrel's axial direction. The bending die gradually bends both sides of the corrugated plate. After bending, the corrugations surround the cross-section of the corrugated tube circumferentially (circumferentially). Then, the bending die gradually bends both sides of the corrugated plate, bending the entire plate into a C-shaped structure with openings, resulting in a C-shaped corrugated plate 2. Figure 2As shown, during the bending process, the corrugated extension direction of the corrugated plate is always consistent with the axial direction of the final corrugated pipe body; In this embodiment, the openings of the two C-shaped corrugated plates 2 face each other. The two C-shaped corrugated plates 2 are then stacked facing each other with their openings opposite. The two sidewall edges of the first C-shaped corrugated plate 2 are aligned with the two sidewall edges of the second C-shaped corrugated plate 2, so that the two sidewall edges overlap along the wall thickness direction, forming an overlapping area. At this point, the two C-shaped corrugated plates 2 together form a closed-loop corrugated tubular body with a rectangular cross-section, as shown below. Figure 3 As shown, the overlapping area is located on the two opposite sides of the rectangular cross section, forming two overlapping strips, so that the two C-shaped corrugated plates 2 together form a closed-loop corrugated tubular body with a rectangular cross section. The above-mentioned overlapping structure can, on the one hand, enable the two C-shaped corrugated plates 2 to be quickly positioned and pre-fixed before welding, avoiding misalignment during splicing; on the other hand, it can increase the welding contact area, improve the weld strength and sealing performance, and is especially suitable for large-diameter soft waveguides with requirements for airtightness and mechanical strength.

[0019] Step S3: Welding the corrugated pipe body The overlapping area of ​​the two C-shaped corrugated plates 2 is welded. In this embodiment, ultrasonic welding is used. The specific operation is as follows: At the splice, a contouring fixture is used to clamp the splice part of the two C-shaped corrugated plates 2 so that the welding is applied to the overlapping area (overlap strip). The inner surface shape of the contouring fixture matches the corrugated shape of the outer surface of the corrugated pipe body 3 to provide uniform clamping force and avoid corrugation deformation during welding. Then, the ultrasonic welding equipment is started and the ultrasonic welding head moves along the overlap strip to complete the welding and form an integrated corrugated pipe body 3. Step S4: Install the flange Flanges are installed at both ends of the bellows body 3. In this embodiment, laser welding is used. A standard rectangular flange is fitted onto the end of the bellows body 3, and the end face of the flange is adjusted to be perpendicular to the axis of the bellows body 3. Then, a laser welding machine is used to weld along the contact perimeter between the flange and the bellows body 3, so that the flange and the bellows body 3 are firmly connected, resulting in a large-diameter flexible waveguide product. Figure 4 As shown; After welding is completed, the weld is visually inspected and tested for air tightness to ensure welding quality. The large-diameter flexible waveguide fabricated in this embodiment is lightweight, flexible, and has a flat flange end face, meeting the requirements for millimeter-wave transmission.

[0020] Example 2

[0021] This embodiment is basically the same as Embodiment 1, except that: In step S1, the metal sheet is made of aluminum alloy strip in the O state with a wall thickness of 0.3 mm. The wavy corrugations formed by stamping are trapezoidal, with flat surfaces at the crests and troughs, which facilitates maintaining the stability of the cross-sectional shape during subsequent bending and splicing. The width of the aluminum strip is still determined based on the perimeter of the target waveguide cross-section. Example 3

[0022] This embodiment is basically the same as Embodiment 1, except that: In step S4, the flange is connected to the bellows body 3 by screws. Specifically, several through holes or rivet nuts are pre-machined on the outer surfaces of both ends of the bellows body 3, and the flange has corresponding mounting holes. After the flange is placed on the end of the bellows body 3, during installation, the flange is placed on the end of the bellows body 3, aligning the through holes of the flange with the threaded holes on the bellows body 3, and then the screws are inserted one by one and tightened. To prevent loosening, thread-locking adhesive can be applied to the screws or spring washers can be added. The advantage of screw connections is that they are easy to install and disassemble, and it is convenient to replace the flange or adjust the waveguide length on site. They are suitable for occasions that require frequent disassembly and assembly.

[0023] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it.

Claims

1. A method for fabricating a large-aperture soft waveguide, characterized in that, Includes the following steps: S1: The metal sheet is processed into a corrugated sheet with a wavy undulation along its length and the corrugations extending along its width using a stamping process. S2: Bend the corrugated plate into a C-shaped structure with an opening, so that the corrugations extend circumferentially along the cross-section of the C-shaped structure. Take two C-shaped structures formed by bending the corrugated plate and stack them facing each other with their openings opposite each other to form a tubular body with a closed-loop corrugated cross-section. S3: Weld the overlapping areas of the two corrugated plates with the C-shaped structure to obtain a corrugated pipe body; S4: Install flanges at both ends of the bellows body.

2. The method for fabricating a large-aperture soft waveguide according to claim 1, characterized in that: The metal sheet in step S1 is an aluminum strip or aluminum alloy strip, in the O state, with a wall thickness of 0.3 mm to 1.5 mm.

3. The method for fabricating a large-aperture soft waveguide according to claim 1, characterized in that: In step S2, the corrugated plate is bent into the C-shaped structure using a bending fixture, and the corrugations of the corrugated plate extend circumferentially along the cross-section of the corrugated pipe body.

4. The method for fabricating a large-aperture soft waveguide according to claim 1, characterized in that: In step S1, the width of the metal plate is determined according to the perimeter of the target rectangular waveguide. The width of each metal plate is the sum of half the perimeter of the cross section and the overlap amount. The perimeter of the cross section formed by the splicing of two C-shaped corrugated plates is equal to the perimeter of the target rectangular waveguide.

5. The method for fabricating a large-aperture soft waveguide according to claim 1, characterized in that: The wave-shaped ripples formed by stamping in step S1 are sinusoidal, trapezoidal, or sawtooth waveforms.

6. The method for fabricating a large-aperture soft waveguide according to claim 1, characterized in that: In step S4, the flange is welded to the end of the bellows body using laser welding.

7. The method for fabricating a large-aperture soft waveguide according to claim 1, characterized in that: In step S4, the bellows body is connected to the flange by screws.

8. A large-aperture soft waveguide, characterized in that, The large-diameter flexible waveguide, prepared by any one of claims 1-7, comprises: a corrugated tube body consisting of two stamped C-shaped corrugated plates stacked and welded together with their sidewall edges overlapping each other, and flanges respectively disposed at both ends of the corrugated tube body.

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