A safe box body manufacturing process based on spinning hooking and laser welding
By using spinning and laser welding processes, the problems of large welding heat deformation, reliance on manual grinding, high part precision, and low automation in safe box manufacturing have been solved, achieving high-strength, low-cost, and fully automated box manufacturing.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- FOSHAN WANJIA SECURITY TECH CO LTD
- Filing Date
- 2026-05-08
- Publication Date
- 2026-07-21
AI Technical Summary
Existing safe manufacturing processes suffer from problems such as large welding thermal deformation, reliance on manual grinding, high precision requirements for parts, and low automation.
By employing spinning and laser welding processes, a mechanical interlocking structure is formed through the combination of high-precision component preparation, spinning mechanical bonding, and laser welding, and then metallurgical fusion is carried out to achieve cold forming and metallurgical bonding of the box body.
The structure strength and dimensional accuracy of the enclosure have been improved, production costs have been reduced, fully automated production has been achieved, the defect rate and human intervention have been reduced, and the concept of green manufacturing has been followed.
Smart Images
Figure CN122425449A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of metal sheet metal enclosure manufacturing technology, specifically to a safe enclosure manufacturing process based on spinning hook joining and laser welding. Background Technology
[0002] As a security device, the structural strength, dimensional accuracy, and sealing performance of a safe are its core performance indicators. The manufacturing process of the safe directly determines these performance characteristics, production efficiency, and manufacturing costs. Currently, the mainstream safe manufacturing process in the industry revolves around multi-piece welding, mainly including single-piece bending, manual assembly, edge welding, and grinding and finishing steps. This process suffers from numerous intractable technical defects in actual production, becoming a key factor restricting the safe manufacturing industry from developing towards high precision, automation, and green manufacturing. Traditional automated sheet metal processing involves: laser cutting for blanking, bending workstation (bending machine + robotic arm) for forming, robotic arm welding (requiring manual clamping), and automatic grinding. The first two processes require an accuracy of ±0.3mm (requiring frequent product accuracy checks to improve first-pass yield). However, robotic arm welding, due to the heat-affected zone and thermal deformation zone, has a probability of weld point collapse, causing automatic grinding to fail (automatic grinding can only smooth out raised weld points). Long-term verification has shown that the first-pass yield is low, necessitating manual compensation for weld point collapse.
[0003] Moreover, high-precision bending workstations and robotic welding are expensive, and the production efficiency of each set of equipment is limited. Low level of automation and high dependence on manpower: In the assembly process, multiple bent parts need to be assembled manually and temporarily fixed with clamps. The welding process, especially the arc welding operation, is highly dependent on the experience of skilled welders. The grinding and correction process also needs to be completed manually. The manual intervention in each process leads to low production efficiency and makes it difficult to guarantee the consistency of product quality. The differences in operation between different operators can easily cause fluctuations in the performance of the box.
[0004] The parts have stringent precision requirements and high processing costs: In order to ensure the uniformity of the door gaps and the dimensional accuracy of the final safe body, the size and angle tolerances of each independently bent side panel, top panel, bottom panel and other parts must be strictly controlled. The stringent precision requirements not only raise the standards for the selection of raw materials, but also put forward high requirements for the precision of processing equipment, and at the same time increase the defect rate of parts processing, resulting in high overall processing costs.
[0005] Large thermal deformation during welding leads to a high product defect rate: Traditional processes often use welding methods such as resistance spot welding and carbon dioxide gas shielded welding. These welding methods involve a large heat input, and localized concentrated heating can cause uncontrollable thermal stress at the corners of the enclosure, leading to deformation problems such as enclosure twisting, collapse, and uneven door frames. This is the main reason for the finished enclosure dimensions being out of tolerance and door gaps not meeting requirements. The defect rate of enclosure forming using this process is relatively high in the industry.
[0006] To address the aforementioned issues, a safe body manufacturing process based on spinning and laser welding is proposed. Summary of the Invention
[0007] The purpose of this invention is to provide a safe box manufacturing process based on spinning and laser welding, which solves the problems of large welding thermal deformation, reliance on manual grinding, high part precision requirements, and low automation in the existing safe box manufacturing process.
[0008] To achieve the above objectives, the present invention provides the following technical solution: a safe cabinet manufacturing process based on spinning hook joining and laser welding, wherein the safe cabinet body is composed of a door frame, a main body, and a back panel, characterized in that: the process includes: S1: High-precision component preparation: Prepare a door frame and back panel formed by stamping in one step, and a "U"-shaped main box blank formed by bending a single steel plate. After welding the "U"-shaped main box blank closed, the outer sides of the main box are flanged to form a forming base for subsequent spinning and hooking, thus completing the preparation of the main box. S2: Spinning mechanical interlocking: The door frame is fitted into the opening end of the main box and positioned. The fitted components are then fed into a radial spinning device. The radial spinning device applies continuous and uniform radial pressure to the fitted parts through forming rollers, causing the metal of the door frame edge and the opening edge of the main box to undergo plastic deformation and interlock with each other, forming a continuous integrated mechanical interlocking structure. This process is cold forming with no heat input. S3: Laser welding strengthening: High-speed scanning welding is performed using laser welding equipment along the joint of the mechanical interlocking structure, so that the interlocking interface is locally melted and a continuous and dense weld is formed, realizing the metallurgical fusion of the door frame and the main box. S4: Rear panel closure: Fit the rear panel with the other open end of the main body and repeat steps S2 and S3 to form a mechanical interlocking structure between the rear panel and the main body and complete the metallurgical fusion strengthening, thereby achieving the closed forming of the safe body.
[0009] Furthermore, in S1, the flange structure formed by the flange treatment is a straight L-shape, and the flange direction is outward from the main body.
[0010] Furthermore, in S2, the radial spinning device includes a core plate and a forming wheel. There are two core plates, which are used to sequentially press and fix the door frame and the main box body. The core plates can drive the clamped workpiece to rotate as a whole, or the forming wheel can revolve around the workpiece.
[0011] Furthermore, the mechanical interlocking structure is a hook-groove interlocking structure, or by changing the profile and feed trajectory of the forming wheel, any one of the following continuous mechanical self-locking structures can be formed: double-edged engagement, trapezoidal locking, or multi-tooth / wave-shaped engagement.
[0012] Furthermore, in S3, the welding position of the laser welding is the top or bottom edge of the joint of the mechanical interlocking structure. During the laser welding process, a protective gas is used for side blowing protection to reduce weld oxidation.
[0013] Furthermore, for safe boxes with non-circular cross-sections, the radial spinning in step S2 adopts a step-by-step spinning method with workpiece indexing rotation and segmented pressure application by forming rollers, to sequentially complete the hooking and forming of each side of the box.
[0014] Furthermore, the spinning forming in S2 can be a combination of spinning and rolling, with straight edge parts of the box body using straight rolling and corner transition areas using radial spinning.
[0015] Furthermore, the spinning process in S2 can be replaced by segmented hydraulic molding, in which the fitted door frame / back panel and the main body are integrally pressed together by a closed mold to form a mechanical interlocking structure.
[0016] Furthermore, the metal sheets used to prepare the door frame, main body, and rear panel are any one of low-carbon steel, aluminum alloy, galvanized steel sheet, pre-coated steel sheet, or stainless steel. The process parameters of the forming wheel and the laser welding process parameters are adjusted according to the material of the sheet.
[0017] Furthermore, after step S4 is completed, the formed safe body does not require polishing and can directly enter the degreasing, phosphating, spraying and curing processes.
[0018] Compared with the prior art, the beneficial effects of the present invention are as follows: This invention provides a safe box manufacturing process based on spinning and laser welding. Firstly, it combines high-precision component one-time forming with spinning cold forming mechanical interlocking and micro-deformation laser welding, eliminating the traditional multi-piece welding method and removing reliance on high-precision bending and subsequent manual grinding. Secondly, it enhances the structural strength of the box through a dual connection method of mechanical interlocking and metallurgical fusion. Thirdly, it reduces the precision requirements of pre-processing, minimizing defective products. Finally, it facilitates the integration of each process step into automated equipment, clearing obstacles to building a fully automated production line. Ultimately, this achieves improved efficiency, reduced costs, stable quality, and green production in safe box manufacturing.
[0019] This invention provides a safe cabinet manufacturing process based on spinning and laser welding, achieving dual protection of cabinet connection strength and significantly improving structural stability. The invention uses spinning cold forming to create a mechanically interlocking structure, achieving macroscopic shear and peel resistance; then, laser welding achieves metallurgical fusion, completing a microscopic molecular-level bond, forming a dual robust connection method of "mechanical interlocking + metallurgical fusion." The overall tensile strength, torsional strength, and impact resistance of this connection method are far superior to traditional corner spot welding or discontinuous fillet welding, and the cabinet exhibits higher structural stability during long-term use, better meeting the security performance requirements of safes.
[0020] Achieving near-net-shape forming and completely eliminating the need for grinding, the environmentally friendly laser welding process results in a minimal heat-affected zone, preventing thermal deformation of the enclosure. Furthermore, the interlocking structure formed by spinning and hooking creates a smooth and flat interface, resulting in continuous, dense, and smooth welds. This eliminates the need for any manual grinding or requires only minimal surface treatment, allowing direct entry into the subsequent painting process, thus achieving near-net-shape forming of the enclosure. The elimination of grinding not only reduces metal dust and noise pollution, aligning with green manufacturing principles, but also avoids the labor and material costs associated with grinding, while shortening the production cycle.
[0021] The yield rate is revolutionaryly improved, and the dimensional accuracy is highly consistent. The final dimensional accuracy of the enclosure and the uniformity of the door gaps are directly guaranteed by a high-rigidity, high-consistency spinning die, rather than relying on the cumulative tolerances of multiple bending parts in the preceding process. This fundamentally eliminates product defects caused by part tolerance deviations and welding thermal deformation. At the same time, this invention relaxes the bending accuracy requirements of the main enclosure blank, reducing the generation of defective products in the preceding processing and significantly improving the yield rate of the enclosure forming process.
[0022] This invention facilitates integration with automated equipment, paving the way for fully automated production lines. Radial spinning is itself a highly efficient and continuous rotational forming process, and laser welding can also achieve automated high-speed scanning welding. The various process stages of this invention are seamlessly connected, requiring no manual intervention. It is easily integrated with loading / unloading robots, CNC positioning platforms, laser welding stations, and finished product inspection equipment, enabling fully unmanned operation from component loading, positioning, spinning and joining, laser welding, finished product inspection, to unloading. The construction of an automated production line can significantly improve production efficiency, and the production line is highly stable, easy to maintain, and suitable for large-scale mass production.
[0023] The invention significantly reduces overall manufacturing costs. The process saves a lot of labor costs for senior welders and grinders; eliminates the purchase and maintenance costs of grinding consumables and grinding equipment; reduces material waste and rework costs caused by defective products; and at the same time, by relaxing the precision requirements of the main body bending process, it reduces the investment in high-precision processing equipment and processing costs, thus achieving a reduction in overall manufacturing costs from multiple dimensions.
[0024] With its wide material adaptability, this invention's "cold spinning + laser welding" process combination is far more adaptable to metallic materials than traditional hot welding processes. As long as the material possesses sufficient plastic deformation capacity to complete the spinning and joining, it can be used as a manufacturing material for safe bodies. In addition to traditional low-carbon steel, it is also applicable to materials such as aluminum alloys, galvanized steel sheets, pre-coated steel sheets, and stainless steel, enabling the manufacture of various types of products such as lightweight high-end safes, rust-proof and corrosion-resistant safes, and fireproof safes, meeting diverse market demands. Attached Figure Description
[0025] Figure 1 This is a schematic diagram of the process flow of the present invention; Figure 2 This is a rear view structural diagram of one type of safe produced by the process of the present invention; Figure 3 This is a schematic diagram of the weld structure of the aluminum alloy interlocking interface of the present invention (which is a cross-sectional view of the safe).
[0026] In the diagram: 1. Door frame; 2. Main body; 3. Back panel; 4. Weld. Detailed Implementation
[0027] 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.
[0028] Example 1 To further understand the content of this invention, a detailed description of the invention is provided with reference to the accompanying drawings. In this embodiment, a square safe body is manufactured using low-carbon steel plates. The specific implementation steps are as follows: Reference Figure 1 - Figure 3 The high-precision components are made of low-carbon steel sheet metal. The door frame 1 and the back panel 3 are formed by one-time stamping using a precision hydraulic press and progressive die, ensuring the contour accuracy of the door frame 1 and the back panel 3 and meeting the positioning requirements of the spinning and hooking. Low-carbon steel sheet of the same specification is taken and bent into a "U"-shaped main box 2 blank by a CNC bending machine. The middle seam of the main box 2 blank is welded closed by laser welding to form a tubular structure. The outer sides of the main box 2 are flanged into straight L-shapes by a flanging machine. The flanging direction is outward of the main box 2 to complete the preparation of the main box 2. In this step, the bending angle and contour dimension tolerance requirements of the main box 2 blank are greatly relaxed compared with the traditional process.
[0029] The spinning mechanical hooking process involves fitting the door frame 1 into one of the open ends of the main housing 2 and achieving precise positioning. The fitting assembly is then fed into a radial spinning device, where two core plates sequentially press and fix the door frame 1 and the main housing 2. The core plates are controlled to drive the clamped workpiece to rotate at a uniform speed, while the forming rollers are controlled to feed radially along the workpiece, applying continuous and uniform radial pressure to the fitting area. This forces the low-carbon steel metal at the edge of the door frame 1 and the edge of the opening of the main housing 2 to undergo plastic deformation, forming a continuous hook-groove mechanical interlocking structure. This process is cold forming with no heat input. Since this embodiment is a square housing, it is actually a square rounded corner housing. It can be formed by pressing in sections step by step using two rollers. The step spinning method, which involves indexing the workpiece and applying pressure in sections with the forming rollers, is used to sequentially complete the hooking and forming of the four sides of the housing.
[0030] Laser welding strengthens the door frame 1 and main box 2 components that have been spun and hooked together, and sends them to the laser welding station. The laser beam of the laser welding equipment is focused on the bottom edge of the mechanical interlocking structure and welded using a high-speed scanning welding method. Argon gas is used for side blowing protection during the welding process, so that the metal at the interlocking interface is locally melted and forms a continuous and dense weld, realizing the metallurgical fusion of the door frame 1 and the main box 2. The weld surface is flat and without protrusions, and no grinding is required.
[0031] The rear panel 3 is closed and precisely positioned by merging the rear panel 3 with the other open end of the main box 2. The above-mentioned spinning mechanical hooking and laser welding strengthening steps are repeated to make the rear panel 3 and the main box 2 form a hook-groove mechanical interlocking structure and complete the metallurgical fusion, thereby realizing the closed forming of the square safe box.
[0032] The subsequent processes involve cooling the molded safe body to room temperature with air, then directly passing it through a hanging chain into the degreasing, phosphating, electrostatic powder coating, and curing processes to complete the overall manufacturing of the safe body.
[0033] Example 2 Manufacturing of lightweight aluminum alloy safe enclosures This embodiment uses aluminum alloy sheets to manufacture a lightweight safe body. Utilizing the good plasticity and light weight of aluminum alloy, combined with the process of this invention, a lightweight high-end safe is manufactured. The specific implementation steps are basically the same as in Embodiment 1, with the difference being: Because aluminum alloys have better plasticity than low-carbon steel, in the spinning mechanical interlocking step, the radial feed and pressure trajectory of the forming roller are adjusted according to the yield strength and elongation of the aluminum alloy, making it easier for the aluminum alloy sheet to form a mechanical interlocking structure and avoiding metal cracking during the forming process. Because the laser reflectivity of aluminum alloys differs from that of low-carbon steel, the power and welding speed of the laser welding equipment are adjusted during the laser welding strengthening process to ensure that the laser beam can effectively melt the interlocking interface of the aluminum alloy and form a dense weld. The aluminum alloy enclosure requires no additional rust prevention treatment, and the painting process can be simplified according to product requirements, further improving production efficiency.
[0034] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.
[0035] 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. A manufacturing process for a safe body based on spinning and laser welding, wherein the safe body comprises a door frame, a main body, and a back panel, characterized in that: The process includes: S1: High-precision component preparation: Prepare a door frame and back panel formed by stamping in one step, and a "U"-shaped main box blank formed by bending a single steel plate. After welding the "U"-shaped main box blank closed, the outer sides of the main box are flanged to form a forming base for subsequent spinning and hooking, thus completing the preparation of the main box. S2: Spinning mechanical interlocking: The door frame is fitted into the opening end of the main box and positioned. The fitted components are then fed into a radial spinning device. The radial spinning device applies continuous and uniform radial pressure to the fitted parts through forming rollers, causing the metal of the door frame edge and the opening edge of the main box to undergo plastic deformation and interlock with each other, forming a continuous integrated mechanical interlocking structure. This process is cold forming with no heat input. S3: Laser welding strengthening: High-speed scanning welding is performed using laser welding equipment along the joint of the mechanical interlocking structure, so that the interlocking interface is locally melted and a continuous and dense weld is formed, realizing the metallurgical fusion of the door frame and the main box. S4: Rear panel closure: Fit the rear panel with the other open end of the main body and repeat steps S2 and S3 to form a mechanical interlocking structure between the rear panel and the main body and complete the metallurgical fusion strengthening, thereby achieving the closed forming of the safe body.
2. The safe body manufacturing process based on spinning and laser welding according to claim 1, characterized in that: In S1, the flange structure formed by the flange treatment is a straight L-shape, and the flange direction is to be flanged outward from the main body.
3. The safe box manufacturing process based on spinning and laser welding according to claim 1, characterized in that: In S2, the radial spinning device includes a core plate and a forming wheel. There are two core plates, which are used to sequentially press and fix the door frame and the main box. The core plates can drive the clamped workpiece to rotate as a whole, or the forming wheel can revolve around the workpiece.
4. The safe box manufacturing process based on spinning and laser welding according to claim 1, characterized in that: The mechanical interlocking structure is a hook-groove interlocking structure, or by changing the profile and feed trajectory of the forming wheel, any one of the following continuous mechanical self-locking structures can be formed: double-edged engagement, trapezoidal locking, or multi-tooth / wave-shaped engagement.
5. The safe body manufacturing process based on spinning and laser welding according to claim 4, characterized in that: In S3, the laser welding position is the top or bottom edge of the joint of the mechanical interlocking structure. During the laser welding process, a protective gas is used for side blowing protection to reduce weld oxidation.
6. The safe box manufacturing process based on spinning and laser welding according to claim 1, characterized in that: For safe boxes with non-circular cross-sections, the radial spinning in step S2 adopts a step-by-step spinning method with workpiece indexing rotation and segmented pressure application by forming rollers, to sequentially complete the hooking and forming of each side of the box.
7. The safe box manufacturing process based on spinning and laser welding according to claim 1, characterized in that: The spinning process in S2 can be achieved by a combination of spinning and rolling. The straight edges of the box body are rolled using straight lines, while the transition areas at the corners of the box body are spun radially.
8. The safe box manufacturing process based on spinning and laser welding according to claim 1, characterized in that: The spinning process in S2 can be replaced by segmented hydraulic molding, which uses a closed mold to press the fitted door frame / back panel and the main body together to form a mechanical interlocking structure.
9. The safe box manufacturing process based on spinning and laser welding according to claim 1, characterized in that: The metal sheets used to prepare the door frame, main body, and rear panel are any one of low-carbon steel, aluminum alloy, galvanized steel sheet, pre-coated steel sheet, or stainless steel. The process parameters of the forming wheel and the laser welding process parameters are adjusted according to the material of the sheet.
10. The safe body manufacturing process based on spinning and laser welding according to claim 1, characterized in that: After step S4 is completed, the formed safe box body does not need to be polished and can directly enter the degreasing, phosphating, spraying and curing processes.