A loader cab welding process

Abstract

The application discloses a loader cab welding process, comprising the following steps: upper tooling, taking the bottom surface and mounting hole of four mounting plates on the bottom frame as the positioning reference to carry out the assembly point of the bottom frame and bottom plate assembly; carrying out the assembly point of the side frame, lock column block and rearview mirror support; positioning and assembling the upper cross beam assembly; after symmetric positioning, clamping and pressing of the front wall, interior decoration support, mounting plate and fixed block, assembling the rear wall, rear middle cross beam and interior decoration support; positioning and assembling the front upper bending plate by taking the interior decoration mounting hole and interior decoration mounting surface as the reference; positioning and assembling the rear upper wall by taking the rear glass mounting surface and side glass mounting surface, forming the overall frame structure; lower tooling, assembling the right side wall, top cover plate, electrical mounting plate, handrail, fixed block, nut and each support on the frame structure. The application improves the welding efficiency and quality of the loader cab, meets the rapid and accurate assembly operation and realizes the mass production requirement.

Description

Technical Field

[0001] This invention relates to a welding process for a loader cab, belonging to the field of manufacturing and processing of engineering machinery body panels. Background Technology

[0002] The cab is a crucial component of the cover parts for loading machinery. It encompasses a complex array of parts, including sheet metal (formed, bent, stamped), shaped tubes, round steel, square steel, thin plates, thick plates, injection molded parts, and glass. The manufacturing precision of the cab determines its appearance quality and the accuracy of its internal and external dimensions. Process flow and methods are indispensable quality assurance measures in the production process, effectively preventing material waste and improving production efficiency, thus significantly impacting the quality and output of cabs.

[0003] Combination Figure 1 As shown, the main structure of the cab of a loader includes a base frame 1, a floor assembly 2, a front bulkhead 3, a rear bulkhead 16, a top cover 8, lifting rings 9, door and lock brackets, left and right rearview mirror brackets, handrails 19, an electrical mounting plate 18, and interior trim brackets 15. In addition, it includes glass, sliding windows, electrical components, interior trim, air conditioning, instrument cluster, control box, and seats. In recent years, with customers' increasing demands for high-quality loader machinery, the quality of the covering components has become crucial, especially the practicality, comfort, and aesthetics of the cab, which have become mandatory indicators. The use of irregularly shaped tubes and pressed parts is increasing, which brings great difficulty to the production and manufacturing of the cab and the control of dimensional accuracy. The appearance quality, assembly efficiency, and installation accuracy of the cab mainly depend on the welding quality of the cab. The welding quality of the cab depends on the quality of the components and the planning and design of the welding process. The quality of the components depends on their respective processing technology and dimensional control methods.

[0004] The welding of existing loader cabs presents the following technological challenges: ① At least three welders are required to work together to complete the assembly of the cab. The assembly work is arduous. During the continuous welding, the crane needs to be turned over multiple times to complete the weld and grinding work at the connection between the bottom frame and the bottom plate. The continuous welding efficiency is low and there are safety hazards.

[0005] ② The interior bracket assembly is difficult. In order to ensure that the interior can be installed accurately, it is necessary to weld it based on the interior and two people are required to work together. The work intensity is high. The interior wears and burns over a long period of time and needs to be replaced frequently, which wastes resources. Although the positioning is accurate, the efficiency is too low and cannot meet the requirements of mass production.

[0006] ③Welding of thin plates results in severe deformation and makes correction difficult. Summary of the Invention

[0007] In view of the problems existing in the prior art, the present invention provides a welding process for loader cabs, which solves the existing cab production problems, can complete welding operations quickly and efficiently, achieve fast and precise assembly operations, and meet the requirements of mass production.

[0008] To achieve the above objectives, the present invention employs a welding process for a loader cab, comprising the following steps: S1. Use pneumatic clamping and splicing tooling to assemble the bottom frame and bottom plate assembly to form the first assembled part; S2. Use an automatic flip-type pneumatic dual-station assembly tool to assemble the left frame, locking block and left rearview mirror bracket to form the second assembly part; use the automatic flip-type pneumatic dual-station assembly tool to assemble the right frame and right rearview mirror bracket to form the third assembly part. S3. Place the first assembly component from step S1 on the first assembly component positioning seat and support seat of the sliding pneumatic automatic clamping assembly tooling, and position it using the bottom surface of the four mounting plates and the mounting holes on the bottom frame as positioning references. S4. Place the second assembly piece from step S2 on the left sliding frame and the third assembly piece on the right sliding frame. Support and position the lower crossbeam using the lower support positioning seat of the left sliding frame. Use the lower gripping mechanism and the upper gripping mechanism for gripping and angle positioning. After the gripping and positioning are completed, start cylinder I to move the left and right sliding frames to the target assembly point. S5. After the left and right sliding frames, carrying the second and third assembly parts, reach the designated assembly point, they are rotated to the designated position through the front upper curved plate positioning mechanism, the upper middle crossbeam assembly positioning mechanism, and the side panel crossbeam assembly positioning mechanism. The upper crossbeam assembly is then placed on the upper middle crossbeam assembly positioning mechanism and the side panel crossbeam assembly positioning mechanism to position the assembly point. S6. Assemble the front bulkhead, interior bracket, mounting plate, and fixing block into a fourth assembly piece and place it on the first assembly piece. Use the front bulkhead positioning mechanism for symmetrical positioning, and use the front bulkhead pressing mechanism and front bulkhead top pressing mechanism for top and pressing before assembling. S7. Assemble the rear bulkhead, rear center crossbeam, and interior trim bracket into the fifth assembly piece; place the fifth assembly piece on the first assembly piece, and use the rear bulkhead positioning and clamping mechanism to tighten and press the assembly points; S8. Place the front upper curved plate on the front upper curved plate positioning mechanism, and use the top interior trim mounting holes and the top interior trim mounting surface as a reference for positioning and splicing. S9. After splicing the upper rear panel, place the upper rear panel on the positioning mechanism of the panel beam assembly, and then position and splice the rear glass mounting surface and the side glass mounting surface. S10. Use the lower tooling to attach the right side panel, top cover plate, electrical installation plate, handrail, fixing block, nuts, and various brackets to the frame structure.

[0009] As an improvement, the pneumatic clamping and splicing fixture used in step S1 includes a base and multiple mounting plate positioning mechanisms, multiple clamping and positioning seats, multiple pressing mechanisms and multiple pins respectively mounted on the base.

[0010] As an improvement, when using a pneumatic clamping and splicing fixture to assemble the bottom frame and bottom plate assembly: Place the base plate of the base plate assembly on the base and position it using the base plate positioning pin, with the base plate as the reference for positioning; position the bending beam I using the hole positioning pin, and position the reinforcing beam IV using the clamping positioning seat II and the bending beam I; position the reinforcing beam III using the clamping positioning seat I and the reinforcing beam IV; position the reinforcing beam I using the bending beam I and the reinforcing beam III; position the bending beam II using the hole positioning pin and the reinforcing beam IV; and pneumatically rotate and clamp the reinforcing beam III, bending beam II, reinforcing beam I, and bending beam I using clamping mechanism I, clamping mechanism II, and clamping mechanism III; position the mounting plate I using mounting plate positioning mechanism I, and position the mounting plate II and the nut using mounting plate positioning mechanism II.

[0011] As an improvement, the plurality of mounting plate positioning mechanisms, plurality of clamping positioning seats, plurality of pressing mechanisms and plurality of pins are all threaded onto the base.

[0012] As an improvement, the automatic flip-type pneumatic dual-station splicing fixture includes a positioner, a dual-station positioner connecting frame connected to the positioner, and multiple cylinder clamping mechanisms, multiple cylinder pressing mechanisms, multiple positioning seats, solenoid valves, locking block positioning seats, and quick clamps respectively installed on the dual-station positioner connecting frame by threads.

[0013] As an improvement, when using an automatic flip-type pneumatic dual-station assembly fixture to assemble the right side frame and the right rearview mirror bracket: Position the components using positioning seats I, II, III, IV, and VI; tighten them using cylinder clamping mechanisms I, II, III, and IV; and press them using cylinder pressing mechanisms I, II, and IV. Place the right rearview mirror bracket on the right A-pillar of the right side frame, position it using positioning seat V, and press it using cylinder pressing mechanism III. After all components are fixed, proceed with welding.

[0014] As an improvement, when using an automatic flip-type pneumatic dual-station assembly fixture to assemble the left-side frame, locking block, and left rearview mirror bracket: Positioning is performed using positioning seat I, positioning seat II, positioning seat III, positioning seat IV and positioning seat VI; clamping is performed using cylinder clamping mechanism I, cylinder clamping mechanism II, cylinder clamping mechanism III and cylinder clamping mechanism IV; and pressing is performed using cylinder pressing mechanism I, cylinder pressing mechanism II and cylinder pressing mechanism IV. The locking block is positioned using a locking block positioning seat and clamped with quick clamps; the left B-pillar of the left frame is clamped using a cylinder clamping mechanism V and positioned with door hinge mounting holes. Welding is performed after all parts are fixed.

[0015] As an improvement, during the joint welding of steps S1-S10, the weld height of the outer weld at the joint of the front panel, rear panel, and upper rear panel with the A-pillar and B-pillar is <3mm.

[0016] As an improvement, the sliding pneumatic automatic clamping and splicing fixture includes a platform and cylinders, sliding frames, limit seats, rear enclosure positioning and pressing mechanisms, first assembly positioning seats, support seats, front enclosure pressing mechanisms, front enclosure tightening mechanisms and front enclosure positioning mechanisms, which are respectively bolted to the platform.

[0017] As an improvement, the sliding frame includes a left sliding frame and a right sliding frame; The left sliding frame includes a lower support positioning seat, a lower gripping mechanism, an upper gripping mechanism, a front upper curved plate positioning mechanism, an upper middle crossbeam assembly positioning mechanism, and a surrounding plate crossbeam assembly positioning mechanism.

[0018] Compared with existing technologies, the loader cab welding process of this invention involves flexible and intelligent process equipment, such as pneumatic clamping and assembly fixtures, automatic tilting pneumatic dual-station assembly fixtures, and sliding pneumatic automatic clamping and assembly fixtures. All of these adopt mechanical positioning and pneumatic clamping, which facilitates the disassembly and replacement of parts. The automatic tilting pneumatic dual-station assembly fixture can not only be used for manual welding, but also for welding in conjunction with robots. The sliding pneumatic automatic clamping and assembly fixture is compatible with all cab welding processes in this series. This welding process is planned and implemented from component to final assembly, which significantly improves welding efficiency and quality, significantly reduces the workload of employees, meets the requirements of fast and precise assembly operations, and realizes the requirements of batch and mass production. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 This is an exploded structural diagram of the loader cab of the present invention; Figure 2 This is a structural schematic diagram of the first assembled component consisting of the bottom frame and the bottom plate assembly of the present invention; Figure 3 This is a schematic diagram of the pneumatic clamping and splicing tooling of the present invention; Figure 4 This is a schematic diagram of the structure of the first assembly component assembled by the pneumatic clamping and splicing tooling of the present invention; Figure 5 This is a schematic diagram of the structure of the second and third assembly components composed of the side frame and the rearview mirror bracket of the present invention. Figure 6 This is a schematic diagram of the structure of the automatic flip-type pneumatic dual-station assembly tooling for assembling the second and third assembly parts of the present invention. Figure 7 This is a schematic diagram of the automatic flip-type pneumatic dual-station splicing tool of the present invention in the first station; Figure 8 This is a schematic diagram of the automatic flip-type pneumatic dual-station splicing tool of the present invention in the second station; Figure 9 This is a schematic diagram of the assembly structure of the loader cab frame of the present invention; Figure 10 This is a schematic diagram of the sliding pneumatic automatic clamping and splicing tooling of the present invention; Figure 11 A schematic diagram of the left sliding frame of the sliding pneumatic automatic clamping and splicing tooling; Figure 12 A structural schematic diagram of the cab frame assembled using a sliding pneumatic automatic clamping and splicing tooling. In the diagram: 1. Bottom frame, 1-1. Reinforcing beam V, 1-2. Bending beam II, 1-3. Reinforcing beam I, 1-4. Bending beam I, 1-5. Mounting plate I, 1-6. Reinforcing beam II, 1-7. Reinforcing beam III, 1-8. Reinforcing beam IV, 1-9. Mounting plate II, 1-10. Nut; 2. Bottom plate assembly, 2-1. Fixing block, 2-2. Bottom plate; 3. Front bulkhead, 4. Right side bulkhead, 5. Right side frame, 5-1. Right A-pillar, 5-2. Middle crossbeam. 5-3. Lower crossbeam; 5-4. Right B-pillar; 6. Front upper curved plate; 7. Left rearview mirror bracket; 8. Top cover plate; 9. Lifting ring; 10. Upper crossbeam assembly; 11. Rear upper panel; 12. Left side frame; 12-1. Left A-pillar; 12-2. Left B-pillar; 12-3. Locking pillar block; 13. Left door assembly; 14. Rear middle crossbeam; 15. Interior trim bracket; 16. Rear panel; 17. Left touch lock bracket; 18. Electrical mounting plate; 19. Armrest; 20. Right rearview mirror bracket. a. Pneumatic clamping and splicing fixture, a1. Base, a2. Mounting plate positioning mechanism I, a3. Clamping positioning seat I, a4. Pressing mechanism I, a5. Clamping positioning seat II, a6. Mounting plate positioning mechanism II, a7. Pressing mechanism II, a8. Pin, a9. Base plate positioning pin, a10. Positioning pin, a11. Hole positioning pin, a12. Pressing mechanism III; b. Automatic flip-type pneumatic double-station splicing fixture, b1. Double-station positioner connecting frame, b2. Cylinder clamping mechanism I, b3. Cylinder pressing mechanism I, b4. Positioning seat I, b5. Cylinder clamping mechanism II, b6. Positioning seat II, b7. Solenoid valve, b8. Cylinder pressing mechanism II, b9. Positioning seat III, b10. Positioning seat IV, b11. Cylinder pressing mechanism III, b12. Positioning seat V, b13. Cylinder pressing mechanism IV, b14. Cylinder clamping mechanism III, b15. Cylinder clamping mechanism IV, b16. Positioning seat VI, b17. Locking block positioning seat, b18. Quick clamp, b19. Cylinder pressing mechanism V; c. Sliding pneumatic automatic clamping and assembly fixture, c1. Platform, c2. Cylinder I, c3. Right sliding frame, c4. Limit seat I, c5. Rear enclosure positioning and pressing mechanism, c6. First assembly component positioning seat, c7. Support seat, c8. Limit seat II, c9. Left sliding frame, c9-1. Lower support positioning seat, c9-2. Lower gripping mechanism, c9-3. Upper gripping mechanism, c9-4. Front upper bending plate positioning mechanism, c9-5. Upper and middle crossbeam assembly positioning mechanism, c9-6. Enclosure crossbeam assembly positioning mechanism, c10. Front enclosure pressing mechanism, c11. Front enclosure tightening mechanism, c12. Front enclosure positioning mechanism. Detailed Implementation

[0021] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this application will be described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the embodiments of this application and the specific features in the embodiments are detailed descriptions of the technical solutions of this application, rather than limitations on the technical solutions of this application. In the absence of conflict, the embodiments of this application and the technical features in the embodiments can be combined with each other.

[0022] like Figures 1-12 As shown, a welding process for a loader cab includes the following steps: S1, such as Figures 2-4 The bottom frame 1 and the bottom plate assembly 2 are assembled using a pneumatic clamping and splicing tool a to form the first assembled part; The pneumatic clamping and splicing tool a includes a base a1, a mounting plate positioning mechanism I a2, a clamping positioning seat I a3, a pressing mechanism I a4, a clamping positioning seat II a5, a mounting plate positioning mechanism II a6, a pressing mechanism II a7, a pin a8, a base plate positioning pin a9, a positioning pin a10, a hole positioning pin a11, and a pressing mechanism III a12; This tooling combines the product's structural form and welding process, and arranges each component according to the principle of central symmetry. The base a1 is milled with a vertical machining center to create a reference surface, with positioning reference grooves of L=20mm and W=5mm, which facilitates quick location of the X-axis and Y-axis references during drilling. The mounting plate positioning mechanism I a2 and mounting plate positioning mechanism II a6 are symmetrically distributed, including a base plate, a cylinder, a positioning block, a positioning plate and a pin. Taking the mounting plate positioning mechanism I a2 as an example: the base plate is installed on the base a1, the cylinder and the positioning block are installed on the base plate, and the positioning plate is installed on the cylinder (the positioning plate can rotate in the XY plane with the cylinder). The positioning block is used to limit the positioning plate. The positioning plate is milled with a positioning surface and drilled with two pin holes. The positioning surface and a pin a8 are used to position the mounting plate I1-5, and the other pin hole is used to insert the pin a8 to form a locked state. The clamping and positioning seats I a3 are symmetrically distributed. Both clamping and positioning seats I a3 and II a5 include U-shaped grooves, positioning plates, and pins. The U-shaped grooves are installed on the base a1, and the positioning plates are connected by pins for flipping and positioning. Other clamping mechanisms are also symmetrically distributed. The cylinders are installed on the base plate, and the pressure plates are installed on the cylinders to perform rotational clamping actions. All the above installations use threaded connections, mainly for the purpose of facilitating disassembly, replacement, and adjustment, reflecting the principle of flexible design.

[0023] Specific welding steps: Place the base plate 2-2 of the base plate assembly 2 on the base a1, and position it using the base plate positioning pin a9, with the base plate 2-2 as the reference for positioning; position the bent beam I 1-4 using the hole positioning pin a11, and position the reinforcing beam IV 1-8 using the clamping positioning seat II a5 and the bent beam I 1-4; position the reinforcing beam III 1-7 using the clamping positioning seat I a3 and the reinforcing beam IV 1-8; position the reinforcing beam I 1-3 using the bent beam I 1-4 and the reinforcing beam III 1-7; position the bent beam II 1-2 using the hole positioning pin a11 and the reinforcing beam IV 1-8; pneumatically rotate and press the reinforcing beam III 1-7, bent beam II 1-2, reinforcing beam I 1-3, and bent beam I 1-4 using the clamping mechanism I a4, clamping mechanism II a7, and clamping mechanism III a12; and press the reinforcing beam II 1-6 and reinforcing beam V... 1-1 Independent template positioning is adopted. Mounting plate positioning mechanism I a2 positions mounting plate I 1-5, and mounting plate positioning mechanism II a6 positions mounting plate II 1-9 and nut 1-10. After welding, the cylinder is depressurized and rotated to reset. Other small parts are then assembled, and the lower part is transferred to the next process to wait for welding. By adopting pre-welding, the overhead crane flipping welding is eliminated, saving energy consumption, reducing labor intensity, and improving welding efficiency. S2, such as Figures 5-8An automatic flip-type pneumatic dual-station assembly fixture b is used to assemble the left frame 12, locking block 12-3, and left rearview mirror bracket 7 to form the second assembly component; the same automatic flip-type pneumatic dual-station assembly fixture b is used to assemble the right frame 5 and right rearview mirror bracket 20 to form the third assembly component. The automatic flip-type pneumatic dual-station assembly fixture b includes a dual-station positioner connecting frame b1, a cylinder clamping mechanism I b2, a cylinder pressing mechanism I b3, a positioning seat I b4, a cylinder clamping mechanism II b5, a positioning seat II b6, a solenoid valve b7, a cylinder pressing mechanism II b8, a positioning seat III b9, a positioning seat IV b10, a cylinder pressing mechanism III b11, a positioning seat V b12, a cylinder pressing mechanism IV b13, a cylinder clamping mechanism III b14, a cylinder clamping mechanism IV b15, and a positioning seat VI. b16, locking block positioning seat b17, quick clamp b18 and cylinder clamping mechanism Vb19; Various positioning seats, solenoid valves, cylinder clamping mechanisms, and cylinder pressing mechanisms are all bolted to the dual-position positioner connecting frame b1. The placement of components is arranged according to the product structure. The cylinder clamping mechanism includes a transition plate and a top block. Because the height of the clamping cylinder varies according to the product height, a transition plate is bolted to the lower end of the cylinder, and the top block is bolted to the end of the piston rod. The length of the top block is designed according to the spatial distance from the product for easy replacement. The cylinder pressing mechanism includes a connecting support, a cylinder, a rotating bracket, a connecting block, and a pressing block. The connecting support uses bolts to fix the cylinder to the dual-position positioner connecting frame b1. The rotating bracket is mounted on the cylinder for rotational movement, and the connecting block is mounted on the rotating bracket... On the bracket, the pressure block is installed on the connecting block to form a rotary clamping mechanism; the automatic positioning mechanism includes a connecting plate, a dual-station positioner connecting frame b1, and a base. The base includes a base and a column. The column includes a positioner (pneumatic motor), an oil mist lubricator, a silencer, a speed control valve, etc. The column is bolted to the base, the connecting plate is installed on the column, and the dual-station positioner connecting frame b1 is installed on the connecting plate to form an automatic flip-type positioning mechanism. The dual-station position can rotate to the most suitable position for operation during welding. It can be linked with a robot to provide process assurance for intelligent and unmanned process planning. The above installation adopts a threaded connection, mainly for the purpose of facilitating disassembly, replacement, and adjustment, reflecting the principle of flexible design.

[0024] The existing process involves marking and positioning the left and right rearview mirror brackets after the frame is assembled, and then welding the locking block to the door after the assembly is assembled. This process is inefficient and cannot meet the requirements of mass production. The welding steps of this invention are as follows: Place the right A-pillar 5-1, middle crossbeam 5-2, lower crossbeam 5-3, and right B-pillar 5-4 into a work station and position them using positioning seats I b4, II b6, III b9, IV b10, and VI b16; tighten them using cylinder clamping mechanisms I b2, II b5, III b14, and IV b15, and press them using cylinder pressing mechanisms I b3, II b8, and IV b13; place the right rearview mirror bracket 20 on the right A-pillar 5-1 of the right side frame 5, position it using positioning seat V b12, and press it using cylinder pressing mechanism III b11. After all parts are fixed, proceed with welding. The welding methods for the lower crossbeam 5-3, left B-pillar 12-2, left A-pillar 12-1, and left rearview mirror bracket 7 at the second workstation are the same as those at the first workstation. The locking pillar block 12-3 is positioned using the locking pillar block positioning seat b17 and clamped with the quick clamp b18. The left B-pillar 12-2 is clamped and positioned using the cylinder clamping mechanism V b19 and the door hinge mounting hole is positioned. Welding is performed after all parts are fixed. During the welding process, the positioner can be controlled at any time to adjust the welding position to the optimal position. After welding is completed, the cylinder is depressurized and rotated to reset, and the lower part is transferred to the next process for welding. This automatic flip-type pneumatic double-station splicing fixture b is designed with mechanical positioning and pneumatic clamping principles. It is a double-station, automatic flip-type, and easy to clamp. It can be linked with a robot and simultaneously meets the requirements of manual welding and robot welding. It eliminates the need for marking and positioning of the left and right rearview mirrors and welding of the locking pillar blocks, thus improving welding efficiency. S3. Place the first assembly component from step S1 on the first assembly component positioning seat c6 and support seat c7 of the sliding pneumatic automatic clamping assembly tooling c. Positioning is mainly based on the bottom surface of the four mounting plates and the mounting holes on the bottom frame 1. The first assembly component positioning seat c6 is specially designed with coarse positioning pins before precise positioning, which aims to achieve rapid and accurate positioning and ensure that the mounting hole distance tolerance is controlled within ±1. The sliding pneumatic automatic clamping and splicing fixture c includes a platform c1, cylinder I c2, right sliding frame c3, limit seat I c4, rear enclosure positioning and pressing mechanism c5, first assembly component positioning seat c6, support seat c7, limit seat II c8, left sliding frame c9, front enclosure pressing mechanism c10, front enclosure top clamping mechanism c11, and front enclosure positioning mechanism c12. This fixture combines the product's structural form and welding process, employing a centrally symmetrical arrangement of its components. Platform C1 is first fabricated by welding, then a vertical machining center is used to mill out the reference surface, including positioning reference grooves with L=20mm and W=5mm, facilitating quick location of the X-axis and Y-axis references during drilling. Various limit seats, support seats, clamping mechanisms, clamping mechanisms, positioning mechanisms, slide rails, and cylinders are all threadedly connected and installed on platform C1. The left and right sliding frames are fabricated by welding. It is connected by slide rails and cylinders, and moves back and forth linearly on platform c1. In order to leave enough working space for the welders, the lower support positioning seat c9-1, the lower gripping mechanism c9-2, the upper gripping mechanism c9-3, the front upper bending plate positioning mechanism c9-4, the upper middle crossbeam assembly positioning mechanism c9-5, and the surrounding plate crossbeam assembly positioning mechanism c9-6 are installed on the left and right sliding frames. All of them are connected by threads. The principle of each gripping mechanism is similar to the principle of the cylinder pressing mechanism in the automatic flip-type pneumatic double-station splicing tool b. S4. Place the second assembly piece from step S2 on the left sliding frame c9 and the third assembly piece on the right sliding frame c3. Support and position the lower crossbeam using the lower support positioning seat c9-1 of the left sliding frame c9. Use the lower gripping mechanism c9-2 and the upper gripping mechanism c9-3 for gripping and angle positioning. After gripping and positioning are completed, start cylinder I c2 to move the left and right sliding frames to the target assembly point. S5. After the left and right sliding frames, carrying the second and third assembly parts, reach the designated assembly points, they are rotated to the designated positions via the front upper curved plate positioning mechanism c9-4, the upper middle crossbeam assembly positioning mechanism c9-5, and the side panel crossbeam assembly positioning mechanism c9-6. The upper crossbeam assembly 10 is then placed on the positioning assembly points (outer shape positioning) of the upper middle crossbeam assembly positioning mechanism c9-5 and the side panel crossbeam assembly positioning mechanism c9-6. S6. Assemble the front bulkhead 3, interior bracket 15, mounting plate, and fixing block 2-1 into a fourth assembly piece and place it on the first assembly piece. Use the front bulkhead positioning mechanism c12 for symmetrical positioning, and use the front bulkhead pressing mechanism c10 and the front bulkhead top pressing mechanism c11 for top pressing and then assembling. S7. Assemble the rear bulkhead 16, the rear center crossbeam 14, and the interior trim bracket 15 into the fifth assembly piece; place the fifth assembly piece on the first assembly piece, and use the rear bulkhead positioning and pressing mechanism c5 to tighten and press the rear assembly points to ensure that the difference between the upper and lower diagonals at the rear glass installation point is ≤5mm. S8. Place the front upper curved plate 6 on the front upper curved plate positioning mechanism c9-4, and use the top interior trim mounting holes and the top interior trim mounting surface as a reference to perform positioning and splicing (hole + shape positioning) to ensure that the difference between the upper and lower diagonals at the front glass mounting point is ≤5mm. S9. After splicing the upper rear panel, place the upper rear panel 11 on the positioning mechanism c9-6 of the panel beam assembly, and then perform positioning splicing (outer shape positioning) on ​​the rear glass mounting surface and the side glass mounting surface to ensure that the difference between the upper and lower diagonals at the rear glass mounting point is ≤5mm. S10, lower tooling, attach the right side panel 4, top cover plate 8, electrical installation plate 18, handrail 19, fixing block 2-1, nuts, various brackets and other small parts to the frame structure, and rivet the rivet nuts to the required position; S11. Full welding and grinding are required for thick plates and intermittent welding for thin plates. The length of each intermittent weld should not be less than 10mm. The weld height of the outer weld at the contact point between the front, rear, and upper rear panels and the A and B pillars should be less than 3mm. Grinding is not required, but the weld spatter in the area near the weld should be ground. S12. Door installation: Ensure uniform door gaps and smooth opening and closing. Weld the left door lock bracket 17 to the required specifications to ensure precise fit between the door lock and the bracket.

[0025] The pneumatic clamping and splicing fixtures, automatic flip-type pneumatic dual-station splicing fixtures, and sliding pneumatic automatic clamping and splicing fixtures mentioned above are based on mechanical positioning and pneumatic clamping principles. The left and right side frames adopt a sliding gripping type and are designed with ladders to facilitate finding a comfortable welding posture, ensuring that the angle between the base plate and the column is 88° and that it cannot tilt to one side, ensuring that the front and rear glass can be accurately installed, and that the diagonal difference between the front and rear glass installation points is ≤5mm.

[0026] Furthermore, those skilled in the art will understand that although some embodiments described herein include certain features found in other embodiments but not others, combinations of features from different embodiments are also within the scope of protection of this invention and form different embodiments. For example, in the embodiments described above, those skilled in the art can use them in combination based on known technical solutions and the technical problems to be solved by this application.

[0027] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A welding process for a loader cab, characterized in that, Includes the following steps: S1. Use a pneumatic clamping and splicing tool (a) to splice the bottom frame (1) and the bottom plate assembly (2) to form the first assembly part; S2. The left frame (12), locking block (12-3) and left rearview mirror bracket (7) are assembled using an automatic flip-type pneumatic double-station assembly tool (b) to form the second assembly; the right frame (5) and right rearview mirror bracket (20) are assembled using an automatic flip-type pneumatic double-station assembly tool (b) to form the third assembly. S3. Place the first assembly piece from step S1 on the first assembly piece positioning seat (c6) and support seat (c7) of the sliding pneumatic automatic clamping assembly tool (c), and position it using the bottom surface and mounting holes of the four mounting plates on the bottom frame (1) as positioning references. S4. Place the second assembly piece from step S2 on the left sliding frame (c9), and place the third assembly piece on the right sliding frame (c3). Support and position the lower crossbeam using the lower support positioning seat (c9-1) of the left sliding frame (c9). Use the lower gripping mechanism (c9-2) and the upper gripping mechanism (c9-3) for gripping and angle positioning. After the gripping and positioning are completed, start cylinder I (c2) to move the left and right sliding frames to the target assembly point. S5. After the left and right sliding frames, carrying the second and third assembly parts, reach the designated assembly point, they are rotated to the designated position through the front upper bending plate positioning mechanism (c9-4), the upper middle crossbeam assembly positioning mechanism (c9-5), and the side panel crossbeam assembly positioning mechanism (c9-6). The upper crossbeam assembly (10) is then placed on the upper middle crossbeam assembly positioning mechanism (c9-5) and the side panel crossbeam assembly positioning mechanism (c9-6) to position the assembly point. S6. Assemble the front bulkhead (3), interior bracket (15), mounting plate, and fixing block (2-1) into a fourth assembly and place it on the first assembly. Use the front bulkhead positioning mechanism (c12) for symmetrical positioning, and use the front bulkhead pressing mechanism (c10) and front bulkhead top pressing mechanism (c11) for top pressing and then assembling. S7. Assemble the rear panel (16), the rear middle crossbeam (14), and the interior bracket (15) into a fifth assembly; place the fifth assembly on the first assembly and use the rear panel positioning and pressing mechanism (c5) to tighten and press the assembly points. S8. Place the front upper curved plate (6) on the front upper curved plate positioning mechanism (c9-4) and position and assemble it based on the top interior trim mounting holes and the top interior trim mounting surface. S9. After splicing the upper panel, place the upper panel (11) on the panel beam assembly positioning mechanism (c9-6) and then position and splice the rear glass mounting surface and the side glass mounting surface. S10. Remove the formed skeleton structure from the sliding pneumatic automatic clamping and splicing fixture (c), and attach the right side panel (4), top cover plate (8), electrical installation plate (18), handrail (19), fixing block (2-1), nut, and each bracket splice point to the skeleton structure.

2. The welding process for a loader cab according to claim 1, characterized in that, The pneumatic clamping and splicing fixture (a) used in step S1 includes a base (a1) and multiple mounting plate positioning mechanisms, multiple clamping and positioning seats, multiple pressing mechanisms and multiple pins respectively installed on the base (a1).

3. The welding process for a loader cab according to claim 2, characterized in that, When using a pneumatic clamping and splicing fixture (a) to assemble the bottom frame (1) and the base plate assembly (2): Place the base plate (2-2) of the base plate assembly (2) on the base (a1) and position it using the base plate positioning pin (a9), with the base plate (2-2) as the reference for positioning; position the bent beam I (1-4) using the hole positioning pin (a11); position the reinforcing beam IV (1-8) using the clamping positioning seat II (a5) and the bent beam I (1-4); position the reinforcing beam III (1-7) using the clamping positioning seat I (a3) ​​and the reinforcing beam IV (1-8); position the reinforcing beam I (1-4) using the bent beam I (1-4) and the reinforcing beam III (1-7). -3); Position the bent beam II (1-2) with the hole positioning pin (a11) and the reinforcing beam IV (1-8), and pneumatically rotate and press the reinforcing beam III (1-7), bent beam II (1-2), reinforcing beam I (1-3) and bent beam I (1-4) with the pressing mechanism I (a4), pressing mechanism II (a7) and pressing mechanism III (a12); Position the mounting plate I (1-5) with the mounting plate positioning mechanism I (a2), and position the mounting plate II (1-9) and nut (1-10) with the mounting plate positioning mechanism II (a6).

4. The welding process for a loader cab according to claim 2, characterized in that, The multiple mounting plate positioning mechanisms, multiple clamping positioning seats, multiple pressing mechanisms, and multiple pins are all threaded onto the base (a1).

5. The welding process for a loader cab according to claim 1, characterized in that, The automatic flip-type pneumatic dual-station splicing fixture (b) includes a positioner, a dual-station positioner connecting frame (b1) connected to the positioner, and multiple cylinder clamping mechanisms, multiple cylinder pressing mechanisms, multiple positioning seats, a solenoid valve (b7), a locking block positioning seat (b17), and a quick clamp (b18) respectively installed on the dual-station positioner connecting frame (b1) by threads.

6. The welding process for a loader cab according to claim 5, characterized in that, When using the automatic flip-type pneumatic dual-station splicing fixture (b) to splice the right side frame (5) and the right rearview mirror bracket (20): Positioning is performed using positioning seats I (b4), II (b6), III (b9), IV (b10), and VI (b16); clamping is performed using cylinder clamping mechanisms I (b2), II (b5), III (b14), and IV (b15); and pressing is performed using cylinder pressing mechanisms I (b3), II (b8), and IV (b13); the right rearview mirror bracket (20) is placed on the right A-pillar (5-1) of the right side frame (5), positioned using positioning seat V (b12), and pressed using cylinder pressing mechanism III (b11); welding is performed after all parts are fixed.

7. The welding process for a loader cab according to claim 5, characterized in that, When using the automatic flip-type pneumatic dual-station assembly fixture (b) to assemble the left frame (12), locking block (12-3), and left rearview mirror bracket (7): Positioning is performed using positioning seats I (b4), II (b6), III (b9), IV (b10), and VI (b16); clamping is performed using cylinder clamping mechanisms I (b2), II (b5), III (b14), and IV (b15); and pressing is performed using cylinder pressing mechanisms I (b3), II (b8), and IV (b13). The locking block (12-3) is positioned using the locking block positioning seat (b17) and clamped using quick clamps (b18); the left B-pillar (12-2) of the left frame (12) is clamped using the cylinder clamping mechanism V (b19) and positioned using the door hinge mounting hole. Welding is performed after all parts are fixed.

8. The welding process for a loader cab according to claim 1, characterized in that, During the joint welding of steps S1-S10, the weld height of the outer weld seam at the joint of the front panel (3), rear panel (16), and rear upper panel (11) with the A-pillar and B-pillar is <3mm.

9. The welding process for a loader cab according to claim 1, characterized in that, The sliding pneumatic automatic clamping and splicing fixture (c) includes a platform (c1) and cylinders, sliding frames with the same structure, limit seats, rear positioning and pressing mechanisms (c5), first assembly positioning seats (c6), support seats (c7), front pressing mechanisms (c10), front tightening mechanisms (c11), and front positioning mechanisms (c12) that are respectively bolted to the platform (c1).

10. The welding process for a loader cab according to claim 9, characterized in that, The sliding frame includes a left sliding frame (c9) and a right sliding frame (c3). The left sliding frame (c9) includes a lower support positioning seat (c9-1), a lower gripping mechanism (c9-2), an upper gripping mechanism (c9-3), a front upper curved plate positioning mechanism (c9-4), an upper middle crossbeam assembly positioning mechanism (c9-5), and a side panel crossbeam assembly positioning mechanism (c9-6).

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