Manufacturing method of frame skin feeding arm structure

Abstract

The invention provides a manufacturing method of a frame skin feeding arm structure, and belongs to the technical field of mechanical arm manufacturing, and the manufacturing method comprises the following specific manufacturing steps: S1, designing a blank model of the feeding arm structure; s2, preparing the lower skin; s3, the side vertical plates, the front vertical plate, the rear vertical plate, the grid type reinforcing ribs and the petal type reinforcing rib shaft sleeves are subjected to overall low-stress material increase-decrease alternating manufacturing; s4, welding the upper skin pre-beveled with the structure processed in S3; s5, rough machining is conducted on the overall frame; s6, carrying out heat treatment on the overall frame subjected to rough machining; and S7, finish machining is conducted on the overall frame subjected to heat treatment, and the feeding arm structure is obtained. By means of additive and subtractive alternate manufacturing, high-energy sound beam assisting and stepped machining, the problems that a traditional feeding arm is weak in welding seam and large in stress can be solved, the rigidity and strength are improved, the service life is prolonged, light-weight, efficient and low-cost manufacturing is achieved, and the novel energy automobile stamping machine is suitable for new energy automobile stamping scenes.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of mechanical arm manufacturing, and in particular to a manufacturing method of a frame-skin feeding arm structure. BACKGROUND

[0002] Large stamping production lines in the field of new energy vehicles have become the core equipment of the industry with efficient and agile production methods. The feeding arm in the high-speed feeding device needs to withstand cyclic loads for a long time, and has high requirements on overall stiffness, fatigue resistance and service life. However, there are many technical bottlenecks in the current manufacturing and structural design of the feeding arm, which is difficult to meet the industry demand.

[0003] In the prior art, for example, a new type of three-dimensional woven mechanical arm and its manufacturing method are disclosed in Chinese Patent No. CN114393605A. Although the method forms a main body by weaving a fiber preform and impregnating and curing resin, and cooperates with a metal joint to achieve lightweight, the structure focuses on improving the precision of conventional mechanical arms, and the combination of the woven main body and the metal joint cannot adapt to the high rigidity required by the large stamping feeding arm. Moreover, the manufacturing process does not involve complex reinforcement structure and additive and subtractive material collaborative process, and cannot balance the strength and lightweight precision.

[0004] For example, a centering feeding small arm for a carrying device is disclosed in Chinese Patent No. CN221018363U. Although the feeding small arm adjusts the attitude and spacing of the sheet material through a three-section arm body and a horizontal rod separation shaft, it relies on traditional mechanical assembly and driving mechanism, and the arm body has many welding seams and residual stress concentration, which is prone to cracks under long-term cyclic load. Moreover, the structure performance is not optimized by innovative manufacturing process, and the inherent problem of weak welding structure strength cannot be solved.

[0005] It can be seen that the current mainstream feeding arm is mostly an aluminum alloy welded structure, which not only has weak welding seams and large residual stress, leading to easy failure in service, but also cannot realize complex reinforcement design by traditional manufacturing process. Although single additive manufacturing can form complex structures, it is prone to stress deformation due to thermal cycling. Therefore, there is an urgent need in the industry for a feeding arm preparation method that can balance high stiffness, lightweight, long service life, and efficient manufacturing to meet the stable operation requirements of large stamping production lines for new energy vehicles. SUMMARY

[0006] The purpose of the present application is to overcome the shortcomings of the existing feeding arm, such as weak welding structure, easy stress deformation and short service life, and to provide a manufacturing method of a frame-skin feeding arm structure.

[0007] The application is implemented by the following technical scheme: a manufacturing method of a frame skin feeding arm structure, the feeding arm structure comprising a lower skin, a side stand, a front stand, a rear stand, a grid type reinforcing rib, a petal type reinforcing rib shaft sleeve and an upper skin.

[0008] The specific manufacturing steps are as follows: S1. Designing a blank model of the feeding arm structure, the blank model not comprising the upper skin, the lower skin, the side stand, the front stand, the rear stand, the grid type reinforcing rib and the petal type reinforcing rib shaft sleeve all reserving a machining allowance; S2. Preparing the lower skin, which is used as a substrate for additive manufacturing of the side stand, the front stand, the rear stand, the grid type reinforcing rib and the petal type reinforcing rib shaft sleeve; S3. Performing integral low-stress additive-subtractive alternating manufacturing on the side stand, the front stand, the rear stand, the grid type reinforcing rib and the petal type reinforcing rib shaft sleeve, after additive manufacturing, using an in-situ subtractive process to machine according to the blank model, alternating to the blank height, and simultaneously machining a bevel and a weight-reducing hole; during additive manufacturing, arranging a high-energy acoustic beam exciter on the lower skin to apply ultrasonic action; S4. Welding the upper skin with a pre-opened bevel to the structure machined in S3 to form an integral frame; S5. Rough machining the integral frame to machine a process hole and a weight-reducing hole; S6. Heat treating the rough machined integral frame; S7. Finely machining the heat treated integral frame to obtain the feeding arm structure.

[0009] The method can effectively solve the core pain points in traditional feeding arm manufacturing through the complete technical chain of "differentiated blank design-substrate reuse-additive-subtractive collaboration-ladder type machining": first, the targeted allowance design of S1 and the lower skin and additive substrate design of S2 reduce material waste and simplify process connection, the integral low-stress additive-subtractive alternating manufacturing of S3 cooperates with the ultrasonic action of the high-energy acoustic beam exciter to significantly reduce structural residual stress, refine alloy grains and improve material density, avoiding the problems of traditional additive deformation cracking and weak welding seam of welded structures; second, the pre-opened bevel welding of S4 ensures the reliable connection of the upper skin and the main structure, and the rough machining-heat treatment-fine machining ladder process of S5-S7 can precisely control the structure precision and mechanical properties, taking into account manufacturing efficiency and product quality; finally, the overall stiffness, strength and fatigue resistance of the feeding arm are greatly improved, the manufacturing cost is reduced, the production efficiency is improved, and the high-speed feeding scene of the new energy vehicle large stamping production line can be adapted under the premise of ensuring lightweight demand, providing reliable technology for high-performance, low-cost and efficient manufacturing of the feeding arm structure.

[0010] Further improvement of the present application, the machining allowance in S1 is set as: no allowance is reserved inside the lower skin, 4mm machining allowance is reserved on the lower surface of the lower skin, 50mm machining allowance is reserved on the outer side of the lower skin corresponding to the inner diameter of the petal-shaped reinforcing rib sleeve; no allowance is reserved on the inner side of the side stand, front stand and rear stand, 3mm machining allowance is reserved on the outer side of the side stand, front stand and rear stand; no allowance is reserved on the outer side and inner side of the petal-shaped reinforcing rib sleeve, 5mm machining allowance is reserved on the inner side of the petal-shaped reinforcing rib sleeve; 5mm machining allowance is reserved on the upper surface of the side stand, front stand, rear stand, grid-shaped reinforcing rib and petal-shaped reinforcing rib sleeve.

[0011] Further improvement of the present application, the lower skin in S2 is a metal plate, and specifically a 2219 aluminum alloy plate with a thickness of 24mm.

[0012] Further improvement of the present application, the single additive manufacturing height in S3 is 50mm, and a 2319 aluminum alloy wire with a diameter of Φ1.2mm is used as the raw material; the in-situ subtractive machining includes machining the outer diameter surface of the side stand, front stand, rear stand, grid-shaped reinforcing rib, petal-shaped reinforcing rib sleeve and the inside of the reinforcing rib to the right place, machining the weight-reducing hole and the upper surface flat, and machining a "Y" type groove around the side stand, front stand, rear stand and grid-shaped reinforcing rib.

[0013] Further improvement of the present application, the upper skin in S4 is a 2219 aluminum alloy plate with a thickness of 20mm, and a circular hole groove is arranged at the position corresponding to the grid-shaped reinforcing rib; the welding method is MIG welding, and the filling material is a 2319 aluminum alloy welding wire with a diameter of Φ1.2mm.

[0014] Further improvement of the present application, the rough machining in S5 includes machining the lower surface and the periphery of the lower skin, the outer side of the side stand, front stand and rear stand to the design size.

[0015] Further improvement of the present application, the heat treatment in S6 is solid solution and aging treatment; the specific system is solid solution at 540℃ for 10h, and aging treatment at 175℃ for 4h.

[0016] Further improvement of the present application, the high-energy acoustic beam exciter in S3 is uniformly arranged on the lower skin, which can improve the solidification process of the additive manufacturing alloy and refine the alloy grains.

[0017] Further improvement of the present application, the finishing in S7 includes machining the assembly position of the side stand and petal-shaped reinforcing rib sleeve to the design accuracy.

[0018] Further improvements of the present application are that the process hole and the weight-reducing hole in S5 are opened on the lower skin and the upper skin.

[0019] From the above technical solutions, the beneficial effects of the present application are: 1. The method can refine aluminum alloy grains, reduce residual stress, and improve material density by alternating additive and subtractive manufacturing with high-energy acoustic beam assistance; meanwhile, the method uses 2219 / 2319 aluminum alloy matching welding to improve joint strength, greatly enhances the overall rigidity and strength and fatigue resistance of the feeding arm structure, and completely solves the service failure problem of the traditional structure.

[0020] 2. The method can reduce material waste through differential allowance design; the stepped processing flow reasonably connects, saves complex tool switching, can improve overall manufacturing efficiency; and integrates additive, subtractive, and welding processes, without the need for multiple equipment transfers, can reduce comprehensive manufacturing costs, and takes into account high precision and economy.

[0021] 3. The method can realize lightweight feeding arm while meeting the dual requirements of "lightweight-rigidity" of high-speed stamping lines; and has a long service life, can stably support large stamping part feeding operations, and provides reliable protection for efficient operation of the production line. BRIEF DESCRIPTION OF DRAWINGS

[0022] In order to more clearly illustrate the technical solutions of the present application, the following will briefly introduce the drawings needed to be used in the description, and obviously, the drawings in the following description are only some embodiments of the present application, and for those skilled in the art, other drawings can also be obtained without creative labor on the basis of these drawings.

[0023] Figure 1 is a structural schematic diagram of the feeding arm structure of the specific embodiment of the present application.

[0024] Figure 2 is a structural schematic diagram of the blank model of the specific embodiment of the present application.

[0025] Figure 3 is a structural schematic diagram of the lower skin of the specific embodiment of the present application.

[0026] Figure 4 is a layout demonstration diagram of the high-energy acoustic beam exciter of the specific embodiment of the present application.

[0027] Figure 5 is a structural schematic diagram of the overall frame of the specific embodiment of the present application.

[0028] Figure 6 is a demonstration diagram of the rough machining of the overall frame of the specific embodiment of the present application.

[0029] In the figure: 1, lower skin; 101, clamping position; 2, side stand; 3, front stand; 4, rear stand; 5, grid type reinforcing rib; 6, petal type reinforcing rib sleeve; 7, upper skin; 8, high-energy acoustic beam exciter. DETAILED DESCRIPTION

[0030] In order to make the purpose, features and advantages of the present application more obvious and easy to understand, the technical solutions in the present application will be clearly and completely described below in combination with the drawings in the specific embodiments. Obviously, the following described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present patent, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the present patent.

[0031] Reference will now be made to Figures 1-6 , and specific embodiments will be described as follows: the manufacturing method of the frame skin feeding arm structure of the present application, the feeding arm structure includes a lower skin 1, a side stand 2, a front stand 3, a rear stand 4, a grid type reinforcing rib 5, a petal type reinforcing rib sleeve 6 and an upper skin 7, the side stand 2 and the grid type reinforcing rib 5 are provided with weight reduction holes.

[0032] The specific manufacturing steps are as follows: S1. Design the blank model of the feeding arm structure, refer to Figure 2 , the blank model does not contain the upper skin 7, and the lower skin 1, the side stand 2, the front stand 3, the rear stand 4, the grid type reinforcing rib 5 and the petal type reinforcing rib sleeve 6 contained therein all reserve machining allowances. The specific machining allowance is set as follows: the inner upper surface of the lower skin 1 does not reserve allowance, the lower surface of the lower skin 1 reserves 4mm machining allowance, the outer side of the lower skin 1 and the inner diameter of the petal type reinforcing rib sleeve 6 correspond to the position reserved 50mm machining allowance; the inner side of the side stand 2, the front stand 3 and the rear stand 4 does not reserve allowance, and the outer side of the side stand 2, the front stand 3 and the rear stand 4 reserves 3mm machining allowance; the outer side and the inner side of the petal type reinforcing rib sleeve 6 does not reserve allowance, and the inner side of the petal type reinforcing rib sleeve 6 reserves 5mm machining allowance; the upper surface of the side stand 2, the front stand 3, the rear stand 4, the grid type reinforcing rib 5 and the petal type reinforcing rib sleeve 6 reserves 5mm machining allowance.

[0033] S2. Prepare the lower skin 1: refer to Figure 3 , the lower skin 1 selects a 2219 aluminum alloy plate profile with a thickness of 24mm, in order to facilitate subsequent clamping and pressing, the outer side of the lower skin 1 reserves 50mm machining allowance as the clamping position 101 around the four sides and the position corresponding to the inner diameter of the petal type reinforcing rib sleeve 6.

[0034] S3. Overall low-stress additive-subtractive manufacturing of the side stand 2, the front stand 3, the rear stand 4, the grid-shaped reinforcing rib 5 and the petal-shaped reinforcing rib sleeve 6: refer to Figure 4 , first, the additive path is planned in a manual programming manner according to the cross-sectional position of each component; 2319 aluminum alloy wire with a diameter of Ф1.2 mm is selected as the additive manufacturing raw material; the additive manufacturing system is started, and the first-stage additive manufacturing of the above components is performed; in the process, the high-energy acoustic beam exciter 8 is uniformly arranged on the lower skin 1, the solidification process of the additive alloy is improved and the grains are refined by applying ultrasonic action, and the additive manufacturing is stopped when the additive height reaches 50 mm; the in-situ subtractive machining system is switched to, and the first-stage additive structure is subtractively machined, so that the outer diameter surface of the side stand 2, the front stand 3, the rear stand 4 and the petal-shaped reinforcing rib sleeve 6 and the inside of the reinforcing rib are machined in place, and the upper surface is machined flat; the above additive and subtractive processes are repeated, and each additive height is 50 mm, until the overall height reaches the blank model height designed in S1; finally, the in-situ subtractive machining equipment is used to machine the weight-reducing holes on the side stand 2 and the grid-shaped reinforcing rib 5 in place, and the upper surface is machined to the height required by the product design of the feeding arm, and a "Y" type groove is machined around the side stand 2, the front stand 3, the rear stand 4 and the grid-shaped reinforcing rib 5.

[0035] S4. Welding the pre-beveled upper skin 7 with the structure machined in S3 to form an overall frame: refer to Figure 5 The upper skin 7 is selected to be a 2219 aluminum alloy plate profile with a thickness of 20 mm, which is first machined to the designed outer dimensions, and then a "Y" type groove is formed around it, and a circular hole groove is formed at the position corresponding to the grid-shaped reinforcing rib 5; the MIG welding method is used to weld the upper skin 7 and the structure prepared in S3 into one body, and the welding filler material is 2319 aluminum alloy welding wire with a diameter of Ф1.2 mm.

[0036] S5. Rough machining of the overall frame to machine process holes and weight-reducing holes: refer to Figure 6 The lower surface and the periphery of the lower skin 1, the outer side of the side stand 2, the front stand 3 and the rear stand 4 are machined to the designed size, and the weight-reducing holes and process holes are machined on the lower skin 1 and the upper skin 7.

[0037] S6. Heat treatment of the rough-machined overall frame: according to the selected aluminum alloy brand, the solid solution + aging treatment process is adopted; the specific system is solid solution temperature 540℃, holding time 10h, aging temperature 175℃, holding time 4h.

[0038] S7. Finishing machining of the heat-treated overall frame: machining the key assembly positions such as the side stand 2 and the petal-shaped reinforcing rib sleeve 6 to the designed precision, that is, the manufacturing of the feeding arm structure is completed.

[0039] The working principle of the method is as follows: firstly, the blank model is designed through three-dimensional software, and different processing allowances are set according to the functional requirements of different parts such as the lower skin 1, the side stand plate 2, the petal-shaped reinforcing rib shaft sleeve 6, etc. -50mm allowance is reserved on the outside of the lower skin 1 and the corresponding position of the shaft sleeve to ensure the stability of the subsequent clamping, 5mm allowance is reserved on the inside of the shaft sleeve to provide adjustment space for finishing, and 5mm allowance is reserved on the upper surface of each part to adapt to the alternating process of additive and subtractive manufacturing, so as to ensure the controllability of the manufacturing process from the design source; then, the 2219 aluminum alloy plate with a thickness of 24mm is used as the lower skin 1 and the additive substrate, which provides a stable support foundation for the overall structure; in the core manufacturing stage, the "electric arc additive - 50mm per segment + in-situ subtractive" alternating mode is adopted, the additive path is planned through manual programming, and the Φ1.2mm 2319 aluminum alloy wire is used to realize precise surfacing, at the same time, the high-energy acoustic beam exciter 8 is uniformly arranged on the lower skin 1, the ultrasonic action is used to interfere with the alloy solidification process and refine the grain, and the in-situ milling is used to timely eliminate the additive layer defects and calibrate the size, finally, the "Y" type groove and the weight-reducing hole are processed; the same material system of 2219 aluminum alloy plate and 2319 aluminum alloy welding wire is selected in the welding link of the upper skin 7, the MIG welding and the circular hole groove design are used to ensure the penetration of the grid-shaped reinforcing rib 5, and the overall frame is formed; subsequently, the performance is further optimized through step-by-step processing, the redundant allowance is removed through rough machining, and the process hole is opened to create conditions for stress release, the 540℃x10h solid solution + 175℃x4h aging treatment promotes the precipitation of strengthening phase of aluminum alloy, finally, the assembly position precision of the side stand plate 2, the petal-shaped reinforcing rib shaft sleeve 6 and the like is controlled within the design requirement range through finishing, and the whole manufacturing process is completed.

[0040] From the material utilization rate, the method can significantly reduce material waste through differentiated allowance design, and avoid size rejection caused by insufficient allowance; in terms of structural performance, the alternating process of additive and subtractive manufacturing is combined with high-energy acoustic beam assistance, which reduces the structural residual stress, so that the grain size is refined from 50μm of traditional additive manufacturing to less than 15μm, greatly improving the material density, and effectively solving the problem of easy deformation and cracking of additive manufacturing; in terms of connection strength, the material matching of 2219 / 2319 aluminum alloy and the post-welding treatment improve the strength of the welding joint, which is much higher than the strength of traditional dissimilar material welding; in terms of comprehensive performance and efficiency, the method can improve the overall manufacturing efficiency through step-by-step processing, and the synergistic effect of heat treatment and finishing can make the feeding arm structure realize lightweight while having high bending stiffness and fatigue life meeting the load demand, thereby reducing the overall manufacturing cost, fully adapting to the high-speed feeding scene of new energy vehicle large-scale stamping production line, and prolonging the service life.

[0041] The foregoing description of the disclosed embodiments enables a person skilled in the art to make or use the application. Modifications of these embodiments will occur to persons of skill in the art, and that the appended claims are intended to cover all such modifications that do not depart from the true spirit and scope of the application. Therefore, the application is not limited to the embodiments shown but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for manufacturing a frame skin feeding arm structure, the feeding arm structure comprising a lower skin (1), side uprights (2), a front upright (3), a rear upright (4), grid-type reinforcing ribs (5), petal-type reinforcing rib bushings (6), and an upper skin (7), characterized in that, Includes the following steps: S1. Design the blank model of the feeding arm structure. The blank model does not include the upper skin (7). The lower skin (1), side plate (2), front plate (3), rear plate (4), grid-type reinforcing rib (5) and petal-type reinforcing rib bushing (6) included therein are all reserved with machining allowance. S2. Prepare the lower skin (1), which is also used as the substrate for additive manufacturing of the side plate (2), front plate (3), rear plate (4), grid-type reinforcing rib (5), and petal-type reinforcing rib bushing (6); S3. The side plate (2), front plate (3), rear plate (4), grid-type reinforcing rib (5) and petal-type reinforcing rib bushing (6) are manufactured in an overall low-stress alternating additive and subtractive manufacturing process. After additive manufacturing, the blank model is processed in situ using the subtractive manufacturing process, alternating to the blank height, while simultaneously processing the bevel and weight reduction holes. During additive manufacturing, a high-energy acoustic beam exciter (8) is arranged on the lower skin (1) to apply ultrasonic action. S4. Weld the pre-beveled upper skin (7) to the structure processed by S3 to form an integral frame; S5. Perform rough machining on the overall frame to create process holes and weight reduction holes; S6. Perform heat treatment on the overall frame after rough machining; S7. The heat-treated overall frame is precision machined to obtain the feeding arm structure.

2. The manufacturing method of a frame skin feeding arm structure according to claim 1, characterized in that, The machining allowances in S1 are set as follows: no allowance is left inside the lower skin (1), a 4mm machining allowance is reserved on the lower surface of the lower skin (1), and a 50mm machining allowance is reserved on the outer side of the lower skin (1) corresponding to the inner diameter of the petal-shaped reinforcing rib bushing (6); no allowance is left on the inner side of the side plate (2), front plate (3) and rear plate (4), and a 3mm machining allowance is reserved on the outer side of the side plate (2), front plate (3) and rear plate (4); no allowance is left on the outer side and inside of the petal-shaped reinforcing rib bushing (6), and a 5mm machining allowance is reserved on the inner side of the petal-shaped reinforcing rib bushing (6); a 5mm machining allowance is reserved on the upper surface of the side plate (2), front plate (3), rear plate (4), mesh reinforcing rib (5) and petal-shaped reinforcing rib bushing (6).

3. A method for manufacturing a frame skin feeding arm structure according to claim 1 or 2, characterized in that, The lower skin (1) mentioned in S2 is a metal sheet, specifically a 2219 aluminum alloy sheet with a thickness of 24mm.

4. The manufacturing method of a frame skin feeding arm structure according to claim 3, characterized in that, The single additive manufacturing height described in S3 is 50mm, and 2319 aluminum alloy wire with a diameter of Φ1.2mm is used as raw material; the in-situ subtractive processing includes machining the outer diameter surface and the inside of the reinforcing ribs of the side plate (2), front plate (3), rear plate (4), grid-type reinforcing rib (5), and petal-type reinforcing rib bushing (6) to the correct position, machining the weight reduction hole and the upper surface flat, and machining "Y"-shaped bevels around the side plate (2), front plate (3), rear plate (4), and grid-type reinforcing rib (5).

5. The manufacturing method of a frame skin feeding arm structure according to claim 4, characterized in that, The upper skin (7) described in S4 is made of 2219 aluminum alloy plate with a thickness of 20mm. A round hole bevel is provided at the position corresponding to the grid-type reinforcing rib (5). The welding method is MIG welding, and the filler material is 2319 aluminum alloy welding wire with a diameter of Φ1.2mm.

6. The manufacturing method of a frame skin feeding arm structure according to claim 5, characterized in that, The roughing process described in S5 includes machining the lower surface and surrounding areas of the lower skin (1), the side panels (2), the front panel (3), and the outer side of the rear panel (4) to the designed dimensions.

7. The manufacturing method of a frame skin feeding arm structure according to claim 6, characterized in that, The heat treatment described in S6 is solution treatment and aging treatment; the specific process is a solution treatment temperature of 540℃ and a holding time of 10h, and an aging treatment temperature of 175℃ and a holding time of 4h.

8. A method for manufacturing a frame skin feeding arm structure according to claim 7, characterized in that, The high-energy acoustic beam exciter (8) described in S3 is uniformly arranged on the lower skin (1), which can improve the solidification process of additive manufacturing alloys and refine alloy grains.

9. A method for manufacturing a frame skin feeding arm structure according to claim 8, characterized in that, The finishing process described in S7 includes machining the assembly positions of the side plate (2) and the petal-shaped reinforcing bushing (6) to the design precision.

10. A method for manufacturing a frame skin feeding arm structure according to claim 9, characterized in that, The process holes and weight reduction holes described in S5 are opened on the lower skin (1) and the upper skin (7).

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