A scooter frame welding device with positioning function

Abstract

The present application relates to the technical field of welding, especially to a scooter frame welding device with positioning function, comprising a welding component and a workbench component, wherein the workbench component is provided with left and right two workstations which can alternately carry out welding operation, the workstation comprises a plurality of first clamps for pressing the pedal and a second clamp for clamping and positioning the front wheel frame; the second clamp comprises a driving unit which can move linearly towards the pedal, a support frame and a rotating rod which synchronously move under the driving of the driving unit, and a gear transmission unit arranged on the support frame and the rotating rod. Through the coordinated tilting movement of the support frame and the rotating rod realized by the single driving, the gear and the toothed plate transmission in the second clamp, the pedal, the arc-shaped frame and the cylinder are quickly, accurately and stably positioned, thereby fundamentally ensuring the welding precision and consistency; the front fork frame is used as the cylinder positioning carrier design, thereby ensuring the welding quality and the compatibility of subsequent assembly.

Description

Technical Field

[0001] This invention relates to the field of welding technology, and in particular to a scooter frame welding device with positioning function. Background Technology

[0002] In the manufacturing process of scooter frames, welding is a key process for connecting various components and forming an overall structure. Currently, common scooter frames are mainly composed of three welded parts: the pedal (M), the rear wheel frame, and the front wheel frame (N). The front wheel frame (N) further includes an arc-shaped frame (N1) and a front fork frame (N2) connected to it. A typical welding process is as follows: first, the lower end of the arc-shaped frame (N1) is welded to the upper surface of the pedal (M), and then a cylinder (N3) for mounting the front fork frame (N2) is welded to the upper end of the arc-shaped frame (N1). To ensure welding accuracy and consistency, existing technologies usually set up corresponding positioning and clamping devices at the welding station. For example, a simple clamp is used to press the pedal, and a separate clamp is used to temporarily fix the arc-shaped frame and other components of the front wheel frame to achieve initial alignment of the components.

[0003] However, in actual welding operations, the above positioning methods have significant shortcomings. Due to the varying shapes of components such as the pedals and curved frames, and the precise welding requirements, existing fixtures are mostly scattered and have limited functions, often only able to fix a single component individually. They struggle to maintain the relative positions of all components being welded synchronously and stably during the welding process. Especially during the assembly welding of the front wheel frame and pedals, the connection angle and position of the curved frame and pedals are prone to deviation due to inconsistent fixture fit or uneven clamping force. This results in poor alignment of the front frame structure after welding, affecting the subsequent installation of the front fork and the overall performance of the vehicle. Furthermore, in traditional single-station welding, loading and unloading cannot be performed in parallel with the welding process, further restricting production efficiency. Therefore, designing a dedicated welding device capable of quickly, accurately, and stably positioning various components of the scooter frame, especially the front wheel frame and pedals, has become a pressing technical problem to be solved in this field. Summary of the Invention

[0004] Therefore, the technical problem to be solved by the present invention is that in the existing welding of scooter frames, the clamps used for the front wheel frame are scattered and have poor coordination, making it difficult to maintain the relative position between the components synchronously and accurately during welding, resulting in low welding accuracy and efficiency.

[0005] The above-mentioned technical problems are solved by the following technical solution: The present invention proposes a scooter frame welding device with positioning function, including a welding component and a workbench component, wherein the workbench component is provided with two workstations, left and right, which can alternately perform welding operations, and the welding component is movably arranged to switch between the two workstations and perform welding operations.

[0006] The workstation includes a plurality of first clamps for pressing the pedals, and a second clamp for clamping and positioning the front wheel frame;

[0007] The second clamp includes a drive unit that can move linearly toward the pedal, a support frame and a rotating rod that are driven synchronously by the drive unit, and a gear transmission unit disposed on the support frame and the rotating rod;

[0008] The gear transmission unit meshes with a fixed toothed plate, so that when the drive unit drives the support frame and the rotating rod to move linearly, it can drive the support frame and the arc frame on it, as well as the rotating rod and the front fork frame and the cylinder on it, to tilt synchronously towards the pedal direction, so that the lower end of the arc frame and the cylinder accurately abut against the preset welding positions of the pedal and the upper end of the arc frame, respectively.

[0009] In a preferred embodiment of the scooter frame welding device with positioning function described in this invention: the welding component includes a track laid on one side of the workbench component, a movable seat slidably disposed on the track, a robotic arm mounted on the movable seat, and a welding torch mounted at the end of the robotic arm.

[0010] In a preferred embodiment of the scooter frame welding device with positioning function described in this invention: the workbench component includes two supports arranged symmetrically on the left and right, a rotating base rotatably mounted on the two supports respectively, a plate horizontally connected between the two rotating bases, and a motor for driving at least one rotating base to rotate, and the two workstations are arranged side by side on the plate.

[0011] In a preferred embodiment of the scooter frame welding device with positioning function described in this invention: the first clamp includes a mounting plate, an L-shaped pressure arm whose middle part is hinged to the upper end of the mounting plate, and a first hydraulic cylinder mounted on the side of the mounting plate. The piston rod end of the first hydraulic cylinder is connected to the end of the L-shaped pressure arm, and a limiting groove is provided on the lower surface of the front end of the L-shaped pressure arm.

[0012] In a preferred embodiment of the scooter frame welding device with positioning function described in this invention: the driving unit of the second clamp includes a base plate, a guide rail mounted on the base plate, a slide block that slides with the guide rail, a slide block fixed to the slide block, and a second hydraulic cylinder that drives the slide block.

[0013] In a preferred embodiment of the scooter frame welding device with positioning function described in this invention: the support frame is rotatably connected to the fixing block provided on the scooter via a rotating shaft, and the upper end of the support frame is provided with a U-shaped groove for accommodating and clamping the arc-shaped frame and a clamping bolt.

[0014] In a preferred embodiment of the scooter frame welding device with positioning function described in this invention: the rotating rod is rotatably disposed on one side of the support frame, and two protrusions are symmetrically provided on both sides of the support frame on the scooter. The upper surface of the protrusion and the fixing block are respectively provided with a first groove and a second groove for supporting the rotating rod.

[0015] In a preferred embodiment of the scooter frame welding device with positioning function described in this invention: the gear transmission unit includes a first gear and a second gear that mesh with the toothed plate. The first gear is fixed on the rotating shaft of the support frame, the second gear is fixed on the rotating rod, and the toothed plate is fixedly installed on the flat plate and positioned in the direction of movement of the scooter.

[0016] In a preferred embodiment of the scooter frame welding device with positioning function described in this invention: the first gear and the second gear are arranged back and forth along the moving direction of the scooter, and are both located on the same side of the toothed plate.

[0017] In a preferred embodiment of the scooter frame welding device with positioning function described in this invention: the first clamp's front end limiting groove is adapted to the shape of the anti-slip protrusion on the upper surface of the pedal, and the lower end of the arc frame is provided with a limiting groove, which is used to achieve horizontal positioning when pressed.

[0018] The beneficial effects of this invention are as follows:

[0019] I. Significantly Improved Production Efficiency: The equipment employs a dual-station design with a movable welding robotic arm, allowing welding operations to be performed at one station while workpiece clamping and unloading occur simultaneously at the other. This layout eliminates the waiting time inherent in traditional single-station welding, enabling near-continuous assembly line operations and significantly improving equipment utilization and overall output efficiency.

[0020] II. Fundamental Improvement in Positioning Accuracy and Welding Stability: The first clamp in the device has a limiting groove at the front end of its pressure arm that matches the shape of the anti-slip protrusion on the pedal, forming a mechanical interlock during clamping and effectively eliminating any possible displacement of the pedal in the horizontal plane. Simultaneously, a similar limiting groove at the lower end of the arc-shaped frame ensures its unique and correct position when docked with the pedal. This distributed mechanical positioning system establishes a stable and precise benchmark for the entire welding process. Furthermore, the second clamp, through the meshing transmission of gears and a fixed toothed plate, transforms the single linear drive into a precise coordinated tilting motion of the support frame and the rotating rod. This allows the arc-shaped frame and the cylinder to automatically and synchronously reach the welding position according to a preset spatial and temporal relationship, fundamentally eliminating the cumulative errors caused by manual step-by-step adjustments and ensuring the consistency of welding quality for batch products.

[0021] III. Simplified System Structure and Enhanced Reliability: This device utilizes the front fork as the support and positioning carrier for the cylinder, indirectly controlling the cylinder by constraining the rotating rod at the lower end of the front fork, eliminating the need to design a separate and complex clamp for the cylinder. Simultaneously, the second clamp achieves coordinated movement of two degrees of freedom using only a single linear drive unit (second hydraulic cylinder) and a gear and toothed plate mechanical linkage mechanism. Its control logic is simple, and the mechanical transmission is reliable. Compared to solutions employing multiple independent drives and complex control algorithms, this significantly reduces system complexity, manufacturing costs, and failure rate.

[0022] IV. Simultaneous Optimization of Welding Quality and Subsequent Assembly Compatibility: The structure of the first and second gears in the second fixture, arranged front and rear on the same toothed plate along the direction of movement, ensures that the arc-shaped frame is positioned on the pedal first, and then the cylinder tilts and fits onto it in a "sequential positioning" manner. This process simulates the actual assembly sequence, making the relative positions of the components during welding more consistent with the final usage state, which helps reduce welding internal stress. At the same time, since the cylinder is always fitted onto the fork frame fixed to the rotating rod, its concentric relationship with the fork frame is determined and maintained before welding. This effectively avoids difficulties in subsequent fork frame assembly caused by welding deformation, and achieves direct guarantee of the final assembly quality through the welding process. Attached Figure Description

[0023] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings of the embodiments of the present invention will be briefly described below. Obviously, the drawings described below only relate to some embodiments of the present invention and are not intended to limit the present invention. Wherein:

[0024] Figure 1 This is an overall schematic diagram of the present application;

[0025] Figure 2 This is a schematic diagram of the workbench component of this application;

[0026] Figure 3 This is a schematic diagram of a single workstation portion of this application;

[0027] Figure 4 This is a schematic cross-section of a single workstation in this application. Figure 1 ;

[0028] Figure 5 This is a schematic cross-section of a single workstation in this application. Figure 2 ;

[0029] Figure 6 This is a schematic diagram of the first fixture in this application;

[0030] Figure 7 This is a schematic diagram of the scooter being welded.

[0031] In the picture:

[0032] 1. Welding components; 11. Track; 12. Movable base; 13. Robotic arm; 14. Welding torch;

[0033] 2. Workbench components; 21. Support frame; 22. Rotary base; 23. Flat plate; 24. Motor; 25. Workstation;

[0034] 3. First clamp; 31. Mounting plate; 32. L-shaped pressure arm; 33. First hydraulic cylinder; 341. Limiting groove one; 342. Limiting groove two;

[0035] 4. Second clamp; 41. Drive unit; 411. Base plate; 412. Guide rail; 413. Slide block; 414. Slide plate; 415. Second hydraulic cylinder; 42. Support frame; 421. Rotary shaft; 422. U-shaped groove; 423. Clamping bolt; 43. Rotating rod; 44. Gear transmission unit; 441. First gear; 442. Second gear; 45. Gear plate; 46. Fixing block; 47. Protrusion; 471. First groove; 472. Second groove;

[0036] M, pedal; M1, anti-slip protrusion; N, front wheel frame; N1, arc frame; N2, front fork frame; N3, cylinder. Detailed Implementation

[0037] To enable those skilled in the art to better understand the present invention, the present invention will be further described in detail below with reference to specific embodiments and accompanying drawings.

[0038] The terminology used in this invention is that which is currently widely used in the art in consideration of the function of the invention; however, these terms may vary according to the intent of those skilled in the art, precedent, or new technology in the art. Furthermore, specific terms may be chosen by the applicant, and in such cases, their detailed meanings will be described in the detailed description of the invention. Therefore, the terms used in this specification should not be construed as simple names, but rather based on their meanings and the overall description of the invention.

[0039] Reference Figures 1-7This embodiment provides a scooter frame welding device with positioning function, including a welding component 1 and a workbench component 2. The workbench component 2 is provided with two alternating welding stations 25. The welding component 1 is movably arranged to switch between the two stations 25 and perform welding operations. Each station 25 includes a plurality of first clamps 3 for pressing the pedal M, and a second clamp 4 for clamping and positioning the front wheel frame N. The second clamp 4 includes a drive unit 41 that can move linearly toward the pedal M. The synchronously moving support frame 42 and rotating rod 43, and the gear transmission unit 44 set on the support frame 42 and rotating rod 43; the gear transmission unit 44 meshes with the fixedly set toothed plate 45, so that when the drive unit 41 drives the support frame 42 and rotating rod 43 to move linearly, it can drive the support frame 42 and its arc frame N1, and the rotating rod 43 and its front fork frame N2 and cylinder N3 to tilt synchronously towards the pedal M, so that the lower end of the arc frame N1 and the cylinder N3 accurately abut against the preset welding positions of the pedal M and the upper end of the arc frame N1, respectively.

[0040] This application mainly consists of a welding component 1, a workbench component 2, and workstations 25 set on the workbench. The workbench component 2 is designed with two workstations 25 arranged symmetrically from left to right, thus forming a dual-workstation 25 operation system. This layout allows welding operations to be performed at one workstation 25 while workpiece clamping and unloading are performed in parallel at the other workstation 25, greatly reducing equipment waiting time and improving overall production efficiency. The welding component 1 (typically including a programmable robotic arm 13 and a welding torch 14) is configured to move along a preset track 11, enabling it to quickly and accurately switch between the two workstations 25 according to instructions, thereby performing welding tasks on the workpieces at both workstations 25 alternately.

[0041] Each workstation 25 is equipped with two key positioning fixture systems. The first set consists of multiple first clamps 3 for clamping and fixing the pedal M. These first clamps 3 are usually evenly distributed around the area of ​​the pedal M to be welded. Driven by hydraulic or pneumatic means, they can stably clamp the pedal M onto the worktable to prevent it from moving or deforming during the welding process, thus providing a solid reference for the entire welding process.

[0042] The key innovation of this invention lies in the second clamp 4, which is used to clamp and position the front wheel frame N (composed of an arc-shaped frame N1, a front fork frame N2, and a cylindrical piece N3 to be welded). This second clamp 4 includes a drive unit 41 (such as a hydraulic cylinder or an electric linear module) that provides linear power to drive the entire clamping mechanism toward the fixed pedal M. The driven components are a support frame 42 and a rotating rod 43; the support frame 42 supports and clamps the arc-shaped frame N1, while the rotating rod 43 is used to interferometry through the lower end hole of the front fork frame N2 and indirectly position the cylindrical piece N3 fitted onto the upper end of the front fork frame N2. The key to achieving precise positioning lies in the gear transmission unit 44 mounted on the support frame 42 and the rotating rod 43, and the toothed plate 45 fixedly connected to the worktable.

[0043] When the drive unit 41 is activated, pushing the support frame 42 and the rotating rod 43 forward in a straight line towards the pedal M, the first gear 441 mounted on the shaft 421 of the support frame 42 and the second gear 442 mounted on the rotating rod 43 simultaneously mesh with the stationary toothed plate 45. This mechanical design transforms the horizontal linear motion into two precisely controlled rotational motions. Specifically, as the linear movement proceeds, the first gear 441 rolls along the toothed plate 45, forcing the support frame 42 to tilt forward (i.e., towards the pedal M) around its shaft 421, thereby causing the lower end of the arc-shaped frame N1 held by it to accurately "land" and fit against the designated welding position at the front end of the pedal M with a predetermined trajectory and angle. Almost simultaneously, the second gear 442 also rolls along the same toothed plate 45, driving the rotating rod 43 to tilt the fork frame N2 and the cylinder N3 on it forward. By pre-calculating the gear ratio and initial position, cylinder N3 will ultimately precisely cover and fit against the upper welding point of the already positioned arc frame N1. This synchronized "movement and tilting" action achieves precise spatial and temporal positioning of arc frame N1 and cylinder N3. They are not placed separately, but rather, under the linkage of a set of mechanisms, they automatically and collaboratively move from an initial posture conducive to material loading to the final welding posture, ensuring that the relative positions of the two with the pedal M fully conform to the design dimensions, and that both joints to be welded (arc frame N1, pedal M, arc frame N1, and cylinder N3) are simultaneously exposed in the optimal welding position.

[0044] Using the fork frame N2 as the support carrier for the cylinder N3 in the second fixture 4 offers multiple synergistic advantages. During initial clamping, the rotating rod 43 is inserted into the mounting hole at the lower end of the fork frame N2. Its inherent double-arm structure naturally and stably supports the cylinder N3 to be welded, automatically aligning the axis of the cylinder N3 with the symmetry plane of the double arms, simplifying the pre-positioning operation of the cylinder N3. More importantly, during the subsequent coordinated tilting motion, the double arms of the fork frame N2 provide two-point symmetrical support for the cylinder N3, effectively preventing rolling or axial displacement of the cylinder N3 during movement and tilting. This ensures that the circumferential angle and axial position of the cylinder N3 are always precisely controllable when it aligns with the upper end of the arc-shaped frame N1. This design cleverly utilizes the structural characteristics of the frame fork itself, transforming them into part of the welding positioning process. It ensures both positioning accuracy and rigidity without requiring complex additional special fixtures, achieving a balance between functional integration and ease of operation. It unifies the welding process (welding of cylinder N3 and arc frame N1) with the final component assembly relationship (assembly of front fork frame N2 and cylinder N3) in the positioning stage. Cylinder N3 is delivered to the welding position along its future actual working axis (i.e. the center line of the two arms of front fork frame N2). This positioning method simulates the final use state, making the stress distribution formed by welding closer to the actual working conditions, which helps to improve the structural reliability of the connecting parts and reduce the later assembly deformation caused by welding internal stress.

[0045] In summary, the device described in this specific embodiment improves the work cycle through the dual-station 25 layout, and solves the problem of synchronous positioning during the welding of multiple parts by using a second fixture 4 with a gear and toothed plate 45 linkage mechanism, thus achieving high precision, high efficiency and automation in the scooter frame welding process.

[0046] Reference Figures 1-3 The welding component 1 includes a track 11 laid on one side of the workbench component 2, a movable seat 12 slidably disposed on the track 11, a robotic arm 13 mounted on the movable seat 12, and a welding torch 14 mounted at the end of the robotic arm 13.

[0047] In this device, the welding component 1 is the core execution unit for realizing automated welding functions, and its design is tightly integrated with the entire dual-station 25 system. Specifically, this component mainly includes a track 11 laid on one side of the workbench component 2, a movable seat 12 slidably mounted on the track 11, a robotic arm 13 fixedly mounted on the movable seat 12, and a welding torch 14 assembled at the end of the robotic arm 13. The track 11 provides a precise linear guide for the movement of the entire welding component 1, and its length design ensures that the travel of the movable seat 12 can completely cover both left and right stations 25. The movable seat 12, as a support platform, is typically driven by a servo motor 24 and a lead screw or rack and pinion mechanism, and can reciprocate along the track 11, thereby quickly and accurately transporting the welding actuator to the target station 25. The robotic arm 13 mounted on it (usually a multi-joint robot or a dedicated welding positioning mechanism) gives the welding torch 14 a high degree of spatial mobility, enabling it to adjust its posture according to a preset program to approach and complete welding operations at multiple locations on the frame (such as the connection between the arc frame N1 and the pedal M, and the connection between the arc frame N1 and the cylinder N3). As the final process execution terminal, the welding torch 14 is responsible for generating the welding heat source to melt the workpiece base material to form a connection.

[0048] Regarding the welding process used, given that scooter frames often use lightweight metal materials such as aluminum alloys to reduce weight, and considering factors such as welding efficiency, penetration control, and deformation, this device preferentially adopts plasma arc welding as the welding method. Plasma arc welding has the advantages of highly concentrated energy, good arc stability, fast welding speed, and narrow heat-affected zone, making it very suitable for automated welding of thin-walled structural components such as scooter frames, which have high requirements for weld strength, appearance quality, and component deformation control. It can ensure aesthetically pleasing weld formation and reliable connection, while minimizing frame deformation caused by welding heat input.

[0049] Reference Figures 1-3 The workbench component 2 includes two supports 21 arranged symmetrically on the left and right, a rotating base 22 rotatably mounted on the two supports 21 respectively, a plate 23 horizontally connected between the two rotating bases 22, and a motor 24 for driving at least one rotating base 22 to rotate. Two workstations 25 are arranged side by side on the plate 23.

[0050] In practice, the workbench component 2 constitutes the rigid foundation and working platform of the entire device. This component mainly includes two symmetrically fixed supports 21 on the ground, providing stable support for the entire workbench. At the top of each support 21, a rotating base 22 is installed, capable of rotating around its own axis. These two rotating bases 22 are rigidly connected by a horizontal plate 23, forming a stable and rotatable platform structure. One rotating base 22 is directly connected to the output shaft of a drive motor 24 (such as a servo motor 24 or a geared motor 24), serving as the power source for active rotation; the other rotating base 22 acts as the driven end. Together, they ensure that the plate 23 can rotate smoothly and accurately. This rotational function allows the entire workstation 25 (along with the clamped workpiece) fixed on the plate 23 to adjust its angle according to the needs of the welding process. This allows the robotic arm 13 and welding torch 14 to approach welds at different positions with better posture, achieving all-position welding and improving welding quality and accessibility.

[0051] On this horizontal plate 23, two identical workstations 25 are arranged side by side. This side-by-side layout is the basic physical basis for the alternating operation mode of the "welding and clamping" dual workstations 25. The structural rigidity and rotation function of the plate 23 ensure that when welding is being carried out on one workstation 25, loading, unloading and positioning operations can be performed on the other workstation 25 without interference. Both can be adjusted to the optimal welding posture when needed, thereby maximizing equipment utilization and production continuity.

[0052] Reference Figure 6 The first clamp 3 includes a mounting plate 31, an L-shaped pressure arm 32 hinged to the upper end of the mounting plate 31 in the middle, and a first hydraulic cylinder 33 mounted on the side of the mounting plate 31. The piston rod end of the first hydraulic cylinder 33 is connected to the end of the L-shaped pressure arm 32, and a limiting groove 341 is provided on the lower surface of the front end of the L-shaped pressure arm 32.

[0053] In a specific embodiment, the first clamp 3 is a quick clamping mechanism designed specifically for the scooter pedal M. It includes a mounting plate 31 as a basic fixing component, which is firmly connected to the plate 23 of the work station 25. An L-shaped pressure arm is connected to the upper end of the mounting plate 31 through a hinge shaft, so that the L-shaped pressure arm 32 can rotate around the hinge point like a lever. A first hydraulic cylinder 33 as a power source is installed on the side of the mounting plate 31. The piston rod of the hydraulic cylinder is connected to the end of the L-shaped pressure arm 32 (i.e. the end away from the workpiece).

[0054] When the pedal M needs to be pressed, the piston rod of the first hydraulic cylinder 33 retracts, pulling the end of the L-shaped pressure arm 32 downward. According to the lever principle, this causes the front end of the L-shaped pressure arm 32 (i.e., the end closest to the workpiece) to lift upward around the hinge point, making room for the pedal M to be placed. After the pedal M is placed in the predetermined position, the piston rod of the hydraulic cylinder extends, pulling the end of the L-shaped pressure arm 32 upward, thereby driving its front end to swing downward quickly and forcefully, finally pressing it against the surface of the pedal M. In particular, a limiting groove 341 matching the shape of the anti-slip protrusion M1 on the upper surface of the pedal M is provided on the lower surface of the front end of the L-shaped pressure arm 32. When the L-shaped pressure arm 32 is pressed down, the limiting groove 341 will precisely engage with the anti-slip protrusion M1 of the pedal M. This design not only provides vertical clamping force, but also effectively restricts any tendency of pedal M to move in the horizontal direction through the interlocking of concave and convex parts, achieving bidirectional positioning and locking. This ensures that pedal M is completely stable and slip-free during subsequent welding, laying a crucial benchmark for the precise welding of the entire frame.

[0055] Reference Figures 3-5 The drive unit 41 of the second clamp 4 includes a base plate 411, a guide rail 412 mounted on the base plate 411, a slide block 413 that slides with the guide rail 412, a slide plate 414 fixed to the slide block 413, and a second hydraulic cylinder 415 that drives the slide plate 414. The support frame 42 is rotatably connected to the fixing block 46 on the slide plate 414 via a rotating shaft 421. The upper end of the support frame 42 is provided with a U-shaped groove 422 for accommodating and clamping the arc frame N1 and a clamping bolt 423. The rotating rod 43 is rotatably mounted on one side of the support frame 42. Two protrusions 47 are symmetrically provided on both sides of the support frame 42 on the slide plate 414. The upper surface of the protrusions 47 and the fixing block 46 are respectively provided with a first groove 471 and a second groove 472 for supporting the rotating rod 43. The gear transmission unit 44 includes a first gear 441 and a second gear 442 that mesh with the gear plate 45. The first gear 441 is fixed to the rotating shaft 421 of the support frame 42, and the second gear 442 is fixed to the rotating rod 43. The gear plate 45 is fixedly mounted on the plate 23 and is located in the moving direction of the slide plate 414. The first gear 441 and the second gear 442 are arranged back and forth along the moving direction of the slide plate 414 and are both located on the same side of the gear plate 45.

[0056] In specific implementation, the second fixture 4 is the mechanism for realizing the coordinated movement and precise positioning of the front wheel frame N components (arc frame N1, front fork frame N2, and cylindrical N3). Its drive unit 41 forms the basis of the entire fixture movement, including a base plate 411 fixedly installed on the plate 23 of the workstation 25. The base plate 411 is provided with a precisely guiding guide rail 412. A slide block 413 forms a sliding engagement with the guide rail 412, and a slide plate 414 is fixedly installed on the slide block 413. The power to drive the slide plate 414 to move linearly comes from the second hydraulic cylinder 415. The cylinder body of the second hydraulic cylinder 415 is usually fixed on the base plate 411, and its piston rod is connected to the slide plate 414, thereby enabling the slide plate 414 and the slide block 413 to move smoothly and linearly back and forth along the guide rail 412.

[0057] A fixed block 46 is fixed to the slide plate 414, and the support frame 42 is rotatably mounted on the fixed block 46 via a horizontal pivot 421. The upper end of the support frame 42 is specially designed with a U-shaped groove 422, the shape of which is adapted to the contour of the arc frame N1 to accommodate and support the arc frame N1. It is also equipped with a locking bolt 423 to lock the arc frame N1 from the side to ensure that it will not come out or shift during movement.

[0058] A rotatable lever 43 is provided on one side of the support frame 42. This lever 43 passes through the lower mounting hole of the front fork N2 and is interference-fitted with the mounting hole to prevent the front fork N2 from wobbling and tipping over. To stably support this lever 43, two protrusions 47 are symmetrically arranged on the slide plate 414 on both sides of the support frame 42. Each protrusion 47 has a first groove 471 machined on its upper surface. At the same time, a second groove 472 is also machined on the fixing block 46 located between the two protrusions 47. When the lever 43 is placed in position, its two ends are respectively supported in the two first grooves 471 and the second groove 472 in the middle, realizing reliable support and axial positioning of the lever 43.

[0059] The core of the design is the gear transmission unit 44, which enables the conversion from linear motion to tilting motion. This unit includes a first gear 441 fixedly mounted on the end of the shaft 421 of the support frame 42, and a second gear 442 fixedly mounted on the rotating rod 43. A long, narrow toothed plate 45 is fixedly mounted on the flat plate 23 of the workbench and used for abutment positioning at one end of the pedal M. Its toothed surface faces upward, and the length direction of the toothed plate 45 is strictly parallel to the linear movement direction of the slide plate 414. Both the first gear 441 and the second gear 442 are engaged with the fixed toothed plate 45, and they are arranged one in front of the other along the movement direction of the slide plate 414, located on the same side of the toothed plate 45.

[0060] Its working principle is as follows: When the second hydraulic cylinder 415 drives the slide plate 414 to move linearly towards the pedal M, the slide plate 414 drives the support frame 42, rotating rod 43, fixed block 46 and two gears on it to move forward together. Since the toothed plate 45 is fixed, the first gear 441 and the second gear 442 are forced to roll along the tooth surface. This rolling motion is converted into the rotation (i.e., tilting) of the support frame 42 around its rotating axis 421 and the rotation of the rotating rod 43 around its own axis. Through the pre-calculated parameters of the gears and toothed plate 45, the matching relationship between the tilting angle and forward displacement of the support frame 42 (and the arc frame N1 on it) and the rotating rod 43 (and the front fork frame N2 and the cylinder N3 on it) can be precisely controlled. Finally, this composite motion ensures that the lower end of the arc frame N1 lands at the welding point of the pedal M at the correct angle, and at the same time, the cylinder N3 at the upper end of the front fork frame N2 also tilts synchronously and fits precisely against the upper end of the arc frame N1, completing the spatial positioning of the two key joints in one go.

[0061] The above design produces the following multi-layered beneficial effects:

[0062] 1. It achieves true collaborative positioning and one-time precise positioning.

[0063] This is the most direct and prominent effect. By mechanically coupling the tilting motion of the support frame 42 and the rotating rod 43 with a common linear drive unit 41 and the same fixed toothed plate 45, the arc-shaped frame N1 and the fork frame N2 (including the cylinder N3) automatically complete a composite motion of "linear forward movement and synchronous tilting" under the drive of a single power source, starting from an initial separated state that facilitates loading. This process ensures that the two components move to the final welding position in one step, strictly according to the preset spatial and temporal relationship, that is, the lower end of the arc-shaped frame N1 accurately lands at the designated point on the pedal M, while the cylinder N3 precisely fits against the upper end of the arc-shaped frame N1. This completely solves the problems of low efficiency and accumulated alignment errors caused by the need for step-by-step, independent adjustment of the two components in the traditional method.

[0064] 2. Extremely high positioning accuracy and repeatability were achieved.

[0065] Its positioning accuracy is determined by the machining and assembly precision of the mechanical hardware. The linear guide 412 ensures the precision of the movement direction; the meshing transmission between the gear and the toothed plate 45 converts linear displacement into a definite rotation angle without slippage or delay. This purely mechanical transmission method with a definite motion relationship ensures that the trajectory of each action is exactly the same, unaffected by the response of the control system or external interference, thus achieving excellent repeatability and providing a fundamental guarantee for the stable and consistent welding quality.

[0066] 3. It greatly simplifies the system structure and control logic.

[0067] This concept replaces a solution that might require multiple independent drives (such as motors 24 or cylinders controlling translation and two rotational degrees of freedom respectively) and complex coordination control algorithms with a single mechanical linkage mechanism. The entire positioning process only requires simple start-stop control of a single linear drive unit 41 (such as a hydraulic cylinder) to automatically generate the required complex coordinated motion trajectory. This not only reduces hardware costs and system complexity but also significantly simplifies electrical control and programming, improving system reliability and ease of maintenance.

[0068] 4. Improved production cycle time and automated production efficiency.

[0069] Because the positioning action is integrated and simplified into a rapid, continuous mechanical motion process, its completion time is far less than that of manual or robotic step-by-step alignment. This efficient and deterministic positioning capability allows it to perfectly match the rhythm of automated welding production lines. In particular, when combined with the dual-station 25 design of this invention, it enables parallel operations of welding and loading / unloading, minimizing equipment waiting time and thus significantly improving overall production efficiency.

[0070] 5. This ensured the quality of welding and the reliability of subsequent assembly.

[0071] This coordinated movement is not only for "placing" the components in the correct position, but also simulates the final assembly geometry between them. The curved frame N1 and the cylinder N3 are delivered to the welding position in a relative posture that meets design requirements, allowing the weld pool to form in the most ideal joint condition. Simultaneously, since the cylinder N3 is indirectly positioned via the fork frame N2, its concentricity with the fork frame N2 is determined and maintained before welding. This fundamentally avoids potential difficulties in assembling the fork frame N2 due to welding deformation, achieving the effect of "welding guarantees assembly."

[0072] In summary, through ingenious mechanical design, the problem of coordinating multiple degrees of freedom of motion is transformed into a deterministic mechanical linkage problem. This provides a comprehensive technical advantage over traditional methods in terms of precision, efficiency, reliability, and cost control for the automated welding of scooter frames.

[0073] The shape and size of the limiting groove 341 are specifically designed to perfectly match the anti-slip protrusion M1 inherent on the upper surface of the pedal M. When the first hydraulic cylinder 33 drives the L-shaped pressure arm 32 to press down, the limiting groove 341 at the front end of the pressure arm will precisely engage with the anti-slip protrusion M1 of the pedal M, like a key being inserted into a lock. This design achieves bidirectional constraint: in the vertical direction, a stable clamping force is provided by the leverage force of the pressure arm; in the horizontal direction, the mechanical interlock between the limiting groove 341 and the protrusion 47 effectively eliminates the possibility of the pedal M sliding or moving in any direction within its own plane, thereby achieving absolute positioning of the pedal M on the workstation 25 and providing an immovable and reliable reference for it as a basic component of the frame.

[0074] It is worth noting that this ingenious positioning concept has been extended to the constraint of the arc-shaped frame N1. A similarly shaped limiting groove 342 is also provided at the lower end of the arc-shaped frame N1 where it connects with the pedal M. When the arc-shaped frame N1 tilts into place under the drive of the second clamp 4, its lower limiting groove 342 will also engage with the edge of the pedal M or a corresponding positioning block pre-set on the pedal M (this is a feasible and known extended implementation). This ensures that the arc-shaped frame N1 not only rests against the pedal M by gravity or simple contact, but also, at the instant of contact with the pedal M, establishes a unique and correct positional relationship in the horizontal plane through the interlocking of concave and convex parts.

[0075] Therefore, the adaptive limiting grooves 342 located at the front end of the first clamp 3 pressure arm and the lower end of the arc frame N1 together constitute a distributed mechanical positioning system. Their core function is to actively and precisely eliminate all degrees of freedom of the component in the horizontal plane at the moment of clamping or contact, achieving rapid and accurate positioning with "instant accuracy upon placement and instant fixation upon pressing." This greatly reduces the reliance on operator adjustment skills, internalizes positioning accuracy into the mechanical structure of the clamp, and fundamentally ensures the repeatability of positioning accuracy when the two core components, pedal M and arc frame N1, are docked, laying a solid foundation for subsequent high-quality automated welding.

[0076] Reference Figures 1-7 The automated welding and positioning process of the scooter frame welding device with positioning function described in this invention is as follows:

[0077] Step 1: Loading and clamping the pedal M: The operator places the pedal M of the scooter onto the flat plate 23 of the currently idle workstation 25, positioning it within the surrounding ring of multiple first clamps 3. The pedal M is initially positioned longitudinally by abutting its front end (the end used for welding the front wheel frame N) against the end face of the toothed plate 45 fixed to the flat plate 23. Subsequently, the control system of the first clamps 3 is activated, and all first hydraulic cylinders 33 extend synchronously, pushing the ends of their respective L-shaped pressure arms 32. The L-shaped pressure arms 32, using their hinge point with the mounting plate 31 as a fulcrum, perform lever motion, causing their front ends (pressure heads) to swing downwards. The limiting groove 341 on the lower surface of the pressure head precisely embeds into the inherent anti-slip protrusions M1 on the upper surface of the pedal M. Through this "embedding and pressing" action applied simultaneously from different positions by multiple first clamps 3, the pedal M is firmly constrained to the surface of the flat plate 23, achieving both vertical clamping and preventing horizontal movement through the interlocking mechanism, establishing a stable reference for the entire welding process.

[0078] Step 2: Clamping and pre-positioning of front wheel frame N components:

[0079] Based on the previous step, the front wheel frame N assembly is clamped: (1) Clamping of the arc frame N1: The arc frame N1 of the front wheel frame N is placed in the U-shaped groove 422 at the top of the support frame 42, which is adapted to the contour of the arc frame N1. Tighten the clamping bolt 423 so that its end is pressed against the midpoint of the side of the arc frame N1, thereby completing the fastening of the arc frame N1 on the support frame 42. (2) Assembly of the front fork frame N2 and the cylinder N3: The rotating rod 43 is passed through the mounting hole at the lower end of the front fork frame N2 (i.e., double wishbone). Then, the assembled front fork frame N2 and rotating rod 43 assembly is placed on the positioning structure of the second clamp 4: the two ends of the rotating rod 43 at the lower end of the front fork frame N2 are respectively placed in the first groove 471 of the two symmetrical protrusions 47 on the slide plate 414 and the second groove 472 of the fixing block 46 to achieve reliable support of the rotating rod 43. Finally, the cylinder N3 to be welded is placed on the upper end of the front fork frame N2. At this point, all components of the front wheel frame N (arc frame N1, front fork frame N2, cylinder N3) have completed the pre-assembly and initial fixation of their relative positions on the second fixture 4.

[0080] Step 3, Coordinated Motion and Precise Positioning: The piston rod of the second hydraulic cylinder 415 is activated and extended, driving the slide plate 414 to make a precise linear motion along the guide rail 412 via the slide block 413 towards the fixed pedal M. This linear motion simultaneously drives the support frame 42 (including the arc frame N1) and the rotating rod 43 (including the front fork frame N2 and the cylinder N3) fixed on the slide plate 414 to move forward together. In this process: (1) Tilt positioning of support frame 42 and arc frame N1: As the slide plate 414 moves forward, the first gear 441 fixed on the rotating shaft 421 of the support frame 42 meshes and rolls with the fixed toothed plate 45. This meshing forces the first gear 441 to rotate, thereby driving the support frame 42 and the arc frame N1 it holds to make a precise tilting motion forward (towards the pedal M) around the rotating shaft 421. The lower end of the arc frame N1 finally accurately lands and fits into the preset welding area at the front end of the pedal M with a predetermined trajectory and angle. (2) Synchronous tilting and positioning of the rotating rod 43, the fork frame N2 and the cylinder N3: Almost simultaneously, the second gear 442 fixed on the rotating rod 43 also meshes and rolls with the same toothed plate 45, driving the rotating rod 43 to tilt the fork frame N2 and the cylinder N3 on it forward.

[0081] The unique advantages of “one in front and one behind moving and tilting” are explained in detail: The design of the first gear 441 and the second gear 442 being arranged in front and behind along the moving direction of the slide plate 414 and meshing with the same tooth plate 45 brings crucial benefits: (1) Sequential avoidance and interference-free movement: The two gears are staggered in front and behind on the tooth plate 45, so that the tilting movement of the support frame 42 (bearing the heavier arc frame N1) and the rotating rod 43 assembly (bearing the front fork frame N2 and the cylinder N3) has a small phase difference in time and space. This avoids the mechanical interference that may occur when the two larger components move simultaneously in a narrow space, ensuring the smooth and reliable movement process. (2) Spatial-temporal sequence conforming to welding logic: This design ensures that the lower end of the arc frame N1 contacts and positions itself on the pedal M first, establishing the first welding reference. Subsequently, the cylinder N3 tilts into place and fits against the stable upper end of the arc frame N1. This "foundation first, then upper layer" sequence fully conforms to the assembly logic of the structure and the welding process sequence, ensuring that each positioning step is based on a stable foundation. (3) Ensuring the accuracy of the final relative position: By accurately calculating the pitch circle diameter of the gear, the installation position, and the tooth pitch of the tooth plate 45, the proportional relationship between the tilt angle and linear displacement of the support frame 42 and the rotating rod 43 can be strictly controlled. This allows the cylinder N3 to automatically cover the upper end of the arc frame N1 at the correct angle and position. The final relative position of the two fully meets the welding requirements, and the axis of the cylinder N3 is naturally aligned with the center of the double arms of the fork frame N2, providing a guarantee for the final assembly of the fork frame N2.

[0082] Step 4, Automated Welding: Once all components have been precisely positioned and locked through the above process, station 25 is ready. The control system instructs the moving seat 12 to move along the track 11, precisely transporting the robotic arm 13, which carries the welding torch 14, above station 25. According to a preset program, the robotic arm 13 drives the welding torch 14 to perform automated welding (e.g., using plasma arc welding) sequentially on the joint between the lower end of the arc frame N1 and the pedal M, and the joint between the upper end of the arc frame N1 and the cylinder N3. Because the components are securely and precisely fixed by the cooperating fixture, the welding process is stable, and the weld quality is uniform.

[0083] Step 5, Cyclic Operation: While welding is being performed at station 25, the loading and clamping operations of steps 1 to 3 can be carried out simultaneously at another station 25. After welding is completed, the robotic arm 13 moves away, the operator releases the clamps, removes the welded frame, and can immediately begin the next cycle of clamping. The welding component 1 then moves to another clamped station 25 for welding, and so on, achieving uninterrupted assembly line production.

[0084] The entire process is centrally controlled by a programmable logic controller (PLC), coordinating the timing and linkage of the hydraulic cylinders, moving base 12, robotic arm 13, and welding power supply. Position sensors can be installed in the system to detect the end point of the slide plate 414's stroke, the clamping status of the pressure arm, etc., ensuring that each step is completed before initiating the next step, thus improving safety and reliability. The groove of the first clamp 3 and the protrusion 47 of the pedal M provide both positioning and error prevention functions; if the pedal M is placed in the wrong direction, it cannot be inserted, ensuring the accuracy of material loading.

[0085] Finally, it should be noted that the methods and devices described in detail above are merely embodiments, and those skilled in the art can modify these embodiments in different ways as long as they do not depart from the scope of the present invention.

Claims

1. A scooter frame welding device with positioning function, characterized in that: It includes a welding component (1) and a workbench component (2), wherein the workbench component (2) is provided with two stations (25) for alternating welding operations, and the welding component (1) is movably configured to switch between the two stations (25) and perform welding operations; The workstation (25) includes a plurality of first clamps (3) for pressing the pedal (M) and a second clamp (4) for clamping and positioning the front wheel frame (N). The second clamp (4) includes a drive unit (41) that can move linearly toward the pedal (M), a support frame (42) and a rotating rod (43) that are driven synchronously by the drive unit (41), and a gear transmission unit (44) disposed on the support frame (42) and the rotating rod (43). The gear transmission unit (44) meshes with the fixed tooth plate (45), so that when the drive unit (41) drives the support frame (42) and the rotating rod (43) to move linearly, it can drive the support frame (42) and its arc frame (N1), as well as the rotating rod (43) and its fork frame (N2) and cylinder (N3) to tilt synchronously toward the pedal (M), so that the lower end of the arc frame (N1) and the cylinder (N3) respectively accurately abut against the preset welding position of the pedal (M) and the upper end of the arc frame (N1); The second clamp (4) driving unit (41) includes a base plate (411), a guide rail (412) mounted on the base plate (411), a slide block (413) slidably engaged with the guide rail (412), a slide plate (414) fixed to the slide block (413), and a second hydraulic cylinder (415) driving the slide plate (414); the support frame (42) is rotatably connected to the slide plate (414) via a pivot (421). The upper end of the support frame (42) is provided with a U-shaped groove (422) for accommodating and clamping the arc-shaped frame (N1) and a clamping bolt (423); the rotating rod (43) is rotatably disposed on one side of the support frame (42), and two protrusions (47) are symmetrically provided on the sliding plate (414) about the two sides of the support frame (42). The upper surface of the protrusions (47) and the fixed block (46) are respectively provided with a support for the rotating rod (43). The first groove (471) and the second groove (472); the gear transmission unit (44) includes a first gear (441) and a second gear (442) meshing with the toothed plate (45). The first gear (441) is fixed on the rotating shaft (421) of the support frame (42), and the second gear (442) is fixed on the rotating rod (43). The toothed plate (45) is fixedly installed on the flat plate (23) and is located in the moving direction of the sliding plate (414). The first gear (441) and the second gear (442) are arranged back and forth along the moving direction of the sliding plate (414) and are both located on the same side of the toothed plate (45). The first clamp (3) includes an L-shaped pressure arm (32). The lower surface of the front end of the L-shaped pressure arm (32) is provided with a limiting groove (341). The limiting groove (341) at the front end of the pressure arm of the first clamp (3) is adapted to the shape of the anti-slip protrusion (M1) on the upper surface of the pedal (M).

2. The scooter frame welding device with positioning function according to claim 1, characterized in that: The welding component (1) includes a track (11) laid on one side of the workbench component (2), a movable seat (12) slidably disposed on the track (11), a robotic arm (13) mounted on the movable seat (12), and a welding torch (14) mounted at the end of the robotic arm (13).

3. The scooter frame welding device with positioning function according to claim 1, characterized in that: The workbench component (2) includes two supports (21) arranged symmetrically on the left and right, a rotating base (22) rotatably mounted on the two supports (21), a plate (23) horizontally connected between the two rotating bases (22), and a motor (24) for driving at least one rotating base (22) to rotate. The two workstations (25) are arranged side by side on the plate (23).

4. The scooter frame welding device with positioning function according to claim 1, characterized in that: The first clamp (3) also includes a mounting plate (31) and a first hydraulic cylinder (33) mounted on the side of the mounting plate (31), wherein the piston rod end of the first hydraulic cylinder (33) is connected to the end of the L-shaped pressure arm (32).

5. The scooter frame welding device with positioning function according to claim 1, characterized in that: The lower end of the arc frame (N1) is provided with a limiting groove (342), which is used to achieve horizontal positioning when pressed.

Images