Manufacturing process and equipment suitable for small part split welding assembly

Abstract

The invention relates to a manufacturing process and equipment suitable for a small part split welding assembly, and belongs to the technical field of small part split welding assembly machining. According to the curvature radius, a plane area, a transition area and a corner area are divided, rhombic grids, gradually-changed rhombic grids and radial fan-shaped grid reinforcing ribs are arranged, the flexural rigidity of all the areas is improved in a targeted mode, and the machining precision of the small part split welding assembly is improved. The method comprises the following steps of: firstly adopting a laser scanner to detect the deformation quantity and dynamically applying reverse prestress in combination with a hydraulic compensation device so as to avoid local collapse or warping, then realizing quick remodeling of different products through a rotatable adaptive block and an elastic compensation mechanism, solving the problems of poor adaptability and large precision loss of a traditional rigid clamp, and finally detecting the deformation quantity by adopting the laser scanner. The defects that a traditional compensation device is slow in response and high in energy consumption are overcome, deformation is accurately corrected in real time, finally, the multi-axis linkage welding gun set is provided with an independent pressure sensor and temperature closed-loop control, it is ensured that welding pressure and temperature are stable, the problems of thermal deformation and insufficient welding in traditional welding are solved, and the overall precision is improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of small-piece sub-welding assembly processing, and particularly relates to a manufacturing process and equipment suitable for small-piece sub-welding assemblies. Background Art

[0002] In the field of manufacturing small-piece sub-welding assemblies of thin plates, due to the thin thickness and complex structure of the parts, problems such as self-weight deformation and stress concentration generally exist during the stamping and welding process. Traditional processes usually adopt a uniform stiffener design, such as arranging regular grid ribs on the whole plate. However, the stress characteristics in the planar area and the bending area are significantly different, and the uniform design results in redundant stiffness in the planar area and insufficient reinforcement in the corner area. After welding, local collapse or warping is likely to occur, and in severe cases, assembly failure is caused. In addition, most of the existing welding jigs are rigid fixed structures and cannot adapt to the deformation compensation requirements of different regions, further exacerbating the accuracy loss.

[0003] To solve the above problems, some improvement schemes attempt to suppress deformation by locally thickening or adding support structures, but such methods significantly increase the material cost and welding complexity. Another technology proposes to use hydraulic or pneumatic compensation devices, but the system response speed is slow and the energy consumption is high, making it difficult to achieve real-time and precise control. Especially for parts with complex curvatures, the existing processes lack targeted treatment of the transition region, resulting in disordered stress transmission paths and easy generation of microcracks at the interface. How to achieve global stiffness matching and deformation control of thin plate parts without sacrificing the lightweight advantage is still the core problem restricting the high-precision sub-welding assembly manufacturing process. In view of this, a manufacturing process and equipment suitable for small-piece sub-welding assemblies have been developed. Summary of the Invention

[0004] To solve the above problems existing in the prior art, the present invention provides a manufacturing process and equipment suitable for small-piece sub-welding assemblies, and solves the problems of the prior art.

[0005] The object of the present invention can be achieved by the following technical solutions:

[0006] A manufacturing process suitable for small-piece sub-welding assemblies includes the following steps:

[0007] S1: First, determine the easily deformed areas of the thin plate parts. According to the curvature radius of the parts, the area with a curvature radius > 500 mm is defined as the planar area, the area with 50 mm < curvature radius ≤ 500 mm is defined as the transition area, and the area with a curvature radius ≤ 50 mm is defined as the corner area. Orthogonal 60° staggered diamond grid stiffeners are arranged on the planar area to form a network structure with balanced bi-directional bending stiffness. Gradient diamond grid stiffeners with an angle linearly changing from 60° to 30° are arranged on the transition area along the direction from the planar area to the corner area. Radial fan-shaped grid stiffeners are arranged on the corner area, and the radial ribs are distributed along the principal stress trajectories;

[0008] S2: Set an adjustable combined fixture at the assembly station of the assembly unit. The adjustable combined fixture is used to realize the sharing of basic modules by different products.

[0009] S4: Adopt a laser scanner to detect the deformation of parts in real time. When the flatness deviation exceeds the threshold value, start the hydraulic compensation device to apply reverse prestress to the deformed area. The magnitude of the reverse prestress is dynamically adjusted according to the deformation.

[0010] S4: Arrange a multi-axis linkage welding torch group at the welding station. Each welding torch is equipped with an independent pressure sensor and a temperature closed-loop control system to achieve high-precision welding of multiple connection points through synchronous control.

[0011] As a further solution of the present invention, in S1, the rib width of the diamond grid stiffeners on the flat area is twice the thickness of the sheet material of the thin plate part, the height is three times the thickness of the sheet material of the thin plate part, and the included angle between adjacent ribs is 60°, so as to balance the in-plane stiffness and reduce the weight.

[0012] As a further solution of the present invention, in S1, the density of the gradually changing diamond grid stiffeners in the transition area increases at equal intervals along the direction from the flat area to the corner area.

[0013] As a further solution of the present invention, in S1, the radius of the radial fan-shaped grid stiffeners in the corner area is 3 to 5 times the thickness of the sheet material.

[0014] A device applicable to the sub-welding assembly of small parts includes a device main body, an adjustable combined fixture arranged on the device main body, a laser scanner, a hydraulic compensation device, and a multi-axis linkage welding torch group slidably arranged on the device main body. The laser scanner is suspended above the adjustable combined fixture and is used to detect the deformation of the workpiece in real time. The adjustable combined fixture is connected to the hydraulic compensation device.

[0015] As a further solution of the present invention, the adjustable combined fixture includes a basic positioning part, a rotating part, a limiting part slidably arranged on the device main body, and an elastic compensation part arranged on the device main body. The rotating part is rotatably arranged at one end of the limiting part, and the elastic compensation part is sleeved on the other end of the limiting part. A clamping area is formed between the basic positioning part and the rotating part. By adjusting the rotating part, different products can share the basic module.

[0016] As a further solution of the present invention, the basic positioning part includes a positioning plate and a plurality of positioning rods arranged on the positioning plate. The plurality of positioning rods slidably penetrate through the positioning plate, and a first spring is sleeved on each of the plurality of positioning rods. The two ends of the first spring are respectively connected to the positioning plate and the positioning rod.

[0017] As a further solution of the present invention, a silica gel sleeve is provided at the end of the positioning rod.

[0018] As a further solution of the present invention, the rotating part is an elastic rotating block.

[0019] As a further solution of the present invention, the elastic compensation part is a second spring. A fixed block is arranged on the device main body. The limiting part is a limiting rod. The limiting rod slidably penetrates through the fixed block. The second spring is sleeved on the limiting rod. Two ends of the second spring are respectively connected to the fixed block and the limiting rod.

[0020] The beneficial effects of the present invention are as follows:

[0021] The plane area, the transition area and the corner area are divided according to the radius of curvature, and diamond grids, gradient diamond grids and radial sector grids are respectively arranged to strengthen the ribs, so as to specifically improve the bending stiffness of each area and avoid local collapse or warping. Then, through the rotatable adapter block and the elastic compensation mechanism, the rapid model change of different products is realized, and the problems of poor adaptability and large precision loss of traditional rigid jigs are solved. Then, a laser scanner is used to detect the deformation amount, and a hydraulic compensation device combined with PID closed-loop control is used to dynamically apply reverse prestress to solve the defects of slow response and high energy consumption of traditional compensation devices, and realize real-time and accurate correction of deformation. Finally, the multi-axis linkage welding torch group is equipped with an independent pressure sensor and temperature closed-loop control to ensure the stability of welding pressure and temperature, solve the problems of thermal deformation and false soldering in traditional welding, and improve the overall precision. Description of the Drawings

[0022] For the convenience of those skilled in the art to understand, the present invention will be further described below with reference to the drawings.

[0023] Figure 1 It is the manufacturing process flow chart of the small-piece sub-welding assembly of the present invention;

[0024] Figure 2 It is the structural schematic diagram of the adjustable combined jig of the present invention;

[0025] Figure 3 It is the structural schematic diagram of the basic positioning part of the present invention.

[0026] Main element symbol description:

[0027] In the figure: 1, device main body; 21, basic positioning part; 211, positioning plate; 212, positioning rod; 213, first spring; 22, rotating part; 23, limiting part; 24, elastic compensation part; 25, fixed block. Specific Embodiments

[0028] To further elaborate on the technical means and effects adopted by the present invention to achieve the predetermined invention purpose, the following describes in detail the specific embodiments, structures, features and effects according to the present invention with reference to the drawings and preferred embodiments.

[0029] See also Figures 1-3 As shown, this embodiment provides a manufacturing process suitable for a small-part welding assembly, comprising the following steps:

[0030] S1: First determine the deformation-prone area of the thin plate parts. The difference in bending stiffness of different curvature areas can reach 5-10 times, which directly affects the deformation sensitivity. Therefore, according to the curvature radius of the parts, the area with a curvature radius of >500mm is defined as the plane area, the area with a curvature radius of 50mm < ≤500mm is defined as the transition area, and the area with a curvature radius of ≤50mm is defined as the corner area. Orthogonal 60° staggered diamond grid reinforcement ribs are arranged in the plane area to form a mesh structure with balanced bidirectional bending stiffness. Gradient diamond grid reinforcement ribs with a linear angle changing from 60° to 30° are arranged along the plane area to the corner area in the transition area. Radial fan-shaped grid reinforcement ribs are arranged in the corner area, and the radial ribs are distributed along the principal stress trace. Among them, the curvature radius is divided according to: plane area (>500mm), approximate plane The structure is mainly subjected to bidirectional bending; in the transition zone (50-500mm), complex stress, such as bending and stretching, is prone to shear slip bands; in the corner zone (≤50mm), three-dimensional stress concentration occurs, and the maximum principal stress is concentrated on the inside. In the plane zone, the orthogonal 60° diamond grid is used, and the bidirectional bending stiffness is balanced; in the transition zone, the gradient diamond grid is used (the angle changes linearly from 60° to 30°), and in the corner zone, the radial fan-shaped grid is distributed along the principal stress trace. The traditional uniform reinforcement rib design leads to redundant stiffness in the plane zone and insufficient reinforcement in the corner zone, which is prone to collapse or warping after welding. Here, the diamond grid in the plane zone optimizes the bidirectional bending performance and improves the stiffness. The gradient design in the transition zone smoothes the stress transfer path and reduces the risk of shear slip; the radial ribs in the corner zone match the principal stress trace, reduce stress concentration, and inhibit microcracks.

[0031] S2: An adjustable modular fixture is set at the assembly station, and the adjustable modular fixture is used to realize the common basic modules of different products;

[0032] S3: A laser scanner is used to detect the deformation of parts in real time. When the flatness deviation exceeds the threshold, the hydraulic compensation device is started to apply reverse prestress to the deformed area. The magnitude of the reverse prestress is dynamically adjusted according to the deformation. The laser scanner and line laser scanning head generate three-dimensional point cloud data. The threshold is set. When the flatness deviation exceeds the preset value, compensation is triggered. The hydraulic actuator is controlled by PID closed loop.

[0033] S4: A multi-axis linkage welding gun group is arranged at the welding station. Each welding gun is equipped with an independent pressure sensor and a temperature closed-loop control system. High-precision welding of multiple connection points is achieved through synchronous control. The multi-axis linkage welding gun group is a 6-axis multi-degree-of-freedom robotic arm that moves along a linear guide rail.

[0034] At present, in the field of manufacturing small-scale welded assemblies of thin plates, some improvement plans attempt to suppress deformation by local thickening or additional support structures, but such methods significantly increase material costs and welding complexity. Other technologies propose the use of hydraulic or pneumatic compensation devices, but the system response speed is slow and the energy consumption is high, making it difficult to achieve real-time precise control. Especially for parts with complex curvatures, the existing process lacks targeted treatment of the transition area, resulting in disordered stress transfer paths and easy generation of microcracks at the interface. How to achieve full-domain stiffness matching and deformation control of thin plate parts without sacrificing the advantages of lightweight is still a core problem restricting the manufacturing process of high-precision welded assemblies.

[0035] In order to solve this problem, in this embodiment, the plane area, transition area, and corner area are first divided according to the radius of curvature, and diamond grids, gradient diamond grids, and radial fan-shaped grid reinforcement ribs are arranged respectively to specifically improve the bending stiffness of each area to avoid local collapse or warping. Then, a rotatable adapter block and an elastic compensation mechanism are used to achieve rapid changeover of different products, thereby solving the problems of poor adaptability and large precision loss of traditional rigid fixtures. A laser scanner is then used to detect the deformation amount, and a hydraulic compensation device with PID closed-loop control is used to dynamically apply reverse prestress to solve the defects of slow response and high energy consumption of traditional compensation devices, thereby realizing real-time and precise correction of deformation. Finally, the multi-axis linkage welding gun group is equipped with an independent pressure sensor and temperature closed-loop control to ensure the stability of welding pressure and temperature, solve the problems of thermal deformation and cold welding in traditional welding, and improve the overall precision.

[0036] In order to better avoid local collapse of the plane area, in one embodiment, the width of the diamond grid reinforcement ribs in the plane area of S1 is twice the thickness of the plate of the thin plate part, and the height is three times the thickness of the plate of the thin plate part. This design can balance the in-plane stiffness under the premise of lightweight and avoid redundant or insufficient stiffness. The angle between adjacent ribs is 60° to balance the in-plane stiffness and reduce weight, and the orthogonal 60° staggered layout optimizes the bidirectional bending performance.

[0037] Since the transition zone is subjected to combined bending and tensile stresses, in order to reduce the risk of interface microcracks, in one embodiment, the density of the gradient diamond grid reinforcement ribs in the transition zone in S1 along the direction from the plane zone to the corner zone is increased at equal intervals, and the reinforcement rib density is gradually increased from the plane zone to the corner zone to achieve a stiffness gradient transition and avoid shear slip bands caused by sudden stress changes. Increasing the density at equal intervals can smooth the stress transfer path and reduce the risk of interface microcracks.

[0038] Due to the small curvature radius in the corner area, the stress concentration is significant. In one embodiment, the radius of the radial fan-shaped grid stiffener in the corner area of S1 is 3 to 5 times the thickness of the sheet. The corner area is designed as a radial fan-shaped grid stiffener, which is distributed along the principal stress trajectory to optimize the stress transfer path. Because of the small curvature radius, the corner area bears complex triaxial stresses of tension, compression, and shear, and the maximum principal stress is usually concentrated on the inner side of the corner. The layout direction of the radial fan-shaped grid stiffener is consistent with the principal stress trajectory, forming a support structure matching the stress field. The ribs of the radial fan-shaped grid stiffener extend along the principal stress direction, gradually dispersing the concentrated stress to the surrounding area, avoiding local stress peaks, reducing the path mutation in stress transfer, lowering the shear strain energy density at the interface, and suppressing microcracks.

[0039] An apparatus applicable to a small-piece sub-welding assembly includes an apparatus main body 1, an adjustable combined fixture arranged on the apparatus main body 1, a laser scanner, a hydraulic compensation device, and a multi-axis linkage welding torch group slidably arranged on the apparatus main body 1. The laser scanner is suspended above the adjustable combined fixture and is used for real-time detection of workpiece deformation. The adjustable combined fixture is connected to the hydraulic compensation device. The adjustable combined fixture includes a basic positioning part 21 arranged on the apparatus main body 1, a rotating part 22, a limiting part 23 slidably arranged on the apparatus main body 1, and an elastic compensation part 24. The rotating part 22 is rotatably arranged at one end of the limiting part 23, and the elastic compensation part 24 is sleeved on the other end of the limiting part 23. A clamping area is formed between the basic positioning part 21 and the rotating part 22, and different products can share the basic module by adjusting the rotating part 22.

[0040] Continuing with the above embodiments, in one embodiment, the basic positioning portion 21 includes a positioning plate 211 and a plurality of positioning rods 212 disposed on the positioning plate 211. The plurality of positioning rods 212 slidably penetrate through the positioning plate 211, and a first spring 213 is sleeved on each of the plurality of positioning rods 212. Two ends of the first spring 213 are respectively connected to the positioning plate 211 and the positioning rod 212. A silica gel sleeve is provided at the end of the positioning rod 212. The rotating portion 22 is an elastic rotating block, and the elastic compensation portion 24 is a second spring. A fixing block 25 is provided on the device body 1, and the limiting portion 23 is a limiting rod. The limiting rod slidably penetrates through the fixing block 25. The second spring is sleeved on the limiting rod, and two ends of the second spring are respectively connected to the fixing block 25 and the limiting rod. The basic positioning portion 21 realizes flexible positioning through the positioning rod 212 and the spring, reducing workpiece scratching. The rotating portion 22 adapts to different product profiles, and the elastic compensation portion 24 absorbs assembly deformation, improving versatility and precision. The second spring combines with the slide rail damping unit to balance the requirements of rigid fixation and flexible compensation. Among them, thin plates are vulnerable to external force damage. Silica gel materials have both elasticity and wear resistance, protecting the surface integrity of the workpiece. The contact hardness between the positioning rod 212 and the workpiece is reduced through the silica gel sleeve, preventing indentation or scratching on the surface of the thin plate, especially suitable for high-gloss parts. In addition, when assembling complex curvature parts, a certain amount of deformation needs to be tolerated. Elastic materials provide buffering, improving clamping stability. Therefore, the elastic rotating block can adapt to small deviations in the workpiece profile, avoiding local stress concentration caused by rigid clamping.

[0041] The working principle and process of the present invention:

[0042] First, the plane area, transition area, and corner area are divided according to the curvature radius of the thin plate part. Orthogonal 60° staggered diamond grid stiffeners are arranged in the plane area to balance the stiffness through a two-way bending design; in the transition area, a gradually changing diamond grid with an angle linearly changing from 60° to 30° is adopted, and the density gradually increases to smooth the stress transfer path. In the corner area, radially distributed fan-shaped grids along the principal stress trace lines are arranged to reduce the stress concentration coefficient through geometric shape optimization. This design aims at the stress characteristics of different areas, realizes global stiffness matching, and suppresses local collapse or warping;

[0043] The adjustable combined fixture flexibly fixes the workpiece through the basic positioning portion 21. The rotating portion 22 adapts to different profiles, and the second spring and the limiting rod in the elastic compensation portion 24 cooperate to absorb deformation errors. The laser scanner detects the deformation amount in real time. When the deviation exceeds the threshold, the hydraulic compensation device applies dynamic reverse prestress through PID closed-loop control to accurately offset the deformation. Subsequently, the 6-axis robotic arm of the multi-axis linkage welding torch group moves along the linear guide rail to the welding station, and multi-spot synchronous welding is achieved through independent pressure sensors and temperature closed-loop control to ensure consistent weld strength, ultimately realizing the efficient and high-precision manufacturing of the thin plate sub-assembly.

[0044] The above are only the preferred embodiments of the present invention and do not impose any formal restrictions on the present invention. Although the present invention has been disclosed above in the preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some changes or modifications to equivalent embodiments of equivalent changes within the scope of the technical solution of the present invention by using the technical content disclosed above. However, as long as it does not depart from the content of the technical solution of the present invention, any brief modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention still fall within the scope of the technical solution of the present invention.

Claims

1. A manufacturing process applicable to small-piece sub-welding assemblies, characterized in that, It includes the following steps: S1: First, determine the easily deformable areas of the thin plate parts. According to the curvature radius of the parts, the areas with a curvature radius > 500 mm are defined as the plane areas, the areas with 50 mm < curvature radius ≤ 500 mm are defined as the transition areas, and the areas with a curvature radius ≤ 50 mm are defined as the corner areas. Orthogonal 60° staggered diamond grid stiffeners are arranged on the plane areas to form a network structure with balanced bi-directional bending stiffness. Gradient diamond grid stiffeners with an angle linearly changing from 60° to 30° are arranged on the transition areas along the direction from the plane areas to the corner areas. Radial fan-shaped grid stiffeners are arranged on the corner areas, and the radial ribs are distributed along the principal stress trajectories; S2: Set an adjustable combined fixture at the assembly station of the assembly. The adjustable combined fixture is used to realize the sharing of basic modules by different products; S3: Use a laser scanner to detect the deformation amount of the parts in real time. When the flatness deviation exceeds the threshold, start the hydraulic compensation device to apply reverse prestress to the deformed area, and the magnitude of the reverse prestress is dynamically adjusted according to the deformation amount; S4: Arrange a multi-axis linkage welding torch group at the welding station. Each welding torch is equipped with an independent pressure sensor and a temperature closed-loop control system to achieve high-precision welding of multiple connection points through synchronous control.

2. The manufacturing process for a small-piece sub-welding assembly according to claim 1, characterized in that, In S1, the rib width of the diamond grid stiffeners on the plane areas is twice the thickness of the sheet material of the thin plate part, the height is three times the thickness of the sheet material of the thin plate part, and the included angle between adjacent ribs is 60° to balance the in-plane stiffness and reduce the weight.

3. The manufacturing process for a small-piece sub-welding assembly according to claim 1, characterized in that, In S1, the density of the gradient diamond grid stiffeners on the transition areas increases at equal intervals along the direction from the plane areas to the corner areas.

4. The manufacturing process for a small-piece sub-welding assembly according to claim 1, characterized in that, In S1, the radius of the radial fan-shaped grid stiffeners in the corner areas is 3 to 5 times the thickness of the sheet material.

5. An apparatus applicable to a small-piece sub-welding assembly, characterized in that, It includes a device main body, an adjustable combined fixture arranged on the device main body, a laser scanner, a hydraulic compensation device, and a multi-axis linkage welding torch group slidably arranged on the device main body. The laser scanner is suspended above the adjustable combined fixture and is used to detect the deformation of the workpiece in real time. The adjustable combined fixture is connected to the hydraulic compensation device.

6. The equipment for small-piece sub-welding assembly according to claim 5, characterized in that The adjustable combined fixture includes a basic positioning part, a rotating part, a limiting part slidably arranged on the device main body, and an elastic compensation part arranged on the device main body. The rotating part is rotatably arranged at one end of the limiting part, and the elastic compensation part is sleeved on the other end of the limiting part. A clamping area is formed between the basic positioning part and the rotating part, and different products can share the basic module by adjusting the rotating part.

7. An apparatus for a small-piece sub-welding assembly according to claim 6, characterized in that, The basic positioning part includes a positioning plate and a plurality of positioning rods arranged on the positioning plate. The plurality of positioning rods slidably penetrate through the positioning plate, and first springs are sleeved on the plurality of positioning rods. Two ends of each first spring are respectively connected to the positioning plate and the positioning rod.

8. An apparatus applicable to a small-piece sub-welding assembly according to claim 7, characterized in that, Silicone sleeves are arranged at the ends of the positioning rods.

9. The device for a small-piece sub-welding assembly according to claim 6, characterized in that, The rotating part is an elastic rotating block.

10. The device for small-piece sub-welding assembly according to claim 6, characterized in that, The elastic compensation part is a second spring. A fixed block is arranged on the device main body. The limiting part is a limiting rod. The limiting rod slidably penetrates through the fixed block. The second spring is sleeved on the limiting rod. Two ends of the second spring are respectively connected to the fixed block and the limiting rod.

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