Automobile front subframe welding production line and automobile front subframe production method

Abstract

The present application relates to a kind of automobile front subframe welding production line and automobile front subframe production method.The automobile front subframe welding production line includes multiple welding workstations, the welding workstations include three-axis positioner, fixture tooling and two welding robots;The three-axis positioner is installed on the bottom wall of welding work station, one side of three-axis positioner is equipped with two welding robots;Two sides of three-axis positioner are rotatably installed with fixture tooling;Welding torch is provided on the welding robot, and the welding torch is used for welding the workpiece clamped on the welding side workbench.So the automobile front subframe production method is applied to the automobile front subframe welding production line, can reasonably distribute the welding workload of each sequence, reduce the welding time of welding a front subframe, improve welding efficiency.

Description

Technical Field

[0001] This invention relates to the field of automotive parts technology, and in particular to a welding production line for a front subframe of an automobile and a method for producing a front subframe of an automobile. Background Technology

[0002] The current traditional front subframe welding production line divides the welding process between the various parts of the front subframe into four steps. The first step welds the rear crossbeam assembly, the second step welds the left longitudinal beam assembly and the right longitudinal beam assembly, the third step welds the front subframe assembly, and the fourth step welds the finished product – the front subframe.

[0003] In traditional front subframes, the loading and welding cycles for each sequence are not independent and can interfere with each other, thus reducing welding efficiency. Furthermore, the traditional four-stage welding process for front subframes leads to an unreasonable distribution of welding workload for each stage, resulting in long welding times and low welding efficiency for each front subframe. Summary of the Invention

[0004] In view of this, the present invention provides a welding production line for automotive front subframes, which allows the loading cycle and welding cycle of each welding workstation to be independent and not interfere with each other. The invention also provides a method for producing automotive front subframes, which can reasonably allocate the welding workload of each sequence, reduce the welding time of welding a front subframe, and improve welding efficiency.

[0005] To achieve one or more of the above objectives or other objectives, the present invention proposes a welding production line for a front subframe of an automobile, comprising multiple welding workstations, wherein each welding workstation includes a three-axis positioner, a fixture, and two welding robots.

[0006] The three-axis positioner is installed on the bottom wall of the welding workstation, and two welding robots are provided on one side of the three-axis positioner;

[0007] The three-axis positioner includes a horizontal central axis and two working axes parallel to the central axis. The side of the three-axis positioner facing the welding robot is the welding side, and the other side of the three-axis positioner away from the welding robot is the preparation side. The two working axes are symmetrically arranged on both sides of the central axis and rotate around the axis of the central axis, so that the working axes can rotate from the preparation side to the welding side, or from the welding side to the preparation side.

[0008] The fixture includes a worktable and several clamping mechanisms, which are used to clamp the workpiece to be welded.

[0009] Several of the clamping mechanisms can be detachably mounted on the worktable, or several of the clamping mechanisms can be fixedly mounted on the worktable;

[0010] Both the preparation side and the welding side are rotatably mounted with a worktable, which rotates around the corresponding working axis.

[0011] The welding robot is equipped with a welding torch, which is used to weld the workpiece held in the worktable on the welding side.

[0012] Furthermore, there are five welding workstations, which are arranged and assembled along the axis of the three-axis positioner, namely, the first welding workstation, the second welding workstation, the third welding workstation, the fourth welding workstation, and the fifth welding workstation.

[0013] A method for producing a front subframe of an automobile, applied to the aforementioned automobile front subframe welding production line, includes the following steps:

[0014] S1: Place the lower plate of the rear crossbeam and the reinforcing plate on the workbench on the preparatory side of the first welding workstation, and fix them with several clamping mechanisms;

[0015] S2: The three-axis positioner of the first welding workstation performs the first rotation of the central axis, so that the worktable equipped with the rear crossbeam lower plate and the reinforcing plate is rotated to the welding side. Two welding robots weld the reinforcing plate and the rear crossbeam lower plate accordingly to obtain the rear crossbeam lower plate assembly.

[0016] At the same time, another welded rear crossbeam lower plate assembly and rear crossbeam upper plate are placed on another workbench on the preparatory side of the first welding workstation and fixed with several clamping mechanisms; then the left lifting lug and lifting lug reinforcing plate are placed on the other side of another workbench of the first welding workstation and fixed with several clamping mechanisms.

[0017] S3: After the welding work on the welding side of the first welding workstation is completed and the preparation work on the preparation side of the first welding workstation is completed, the three-axis positioner of the first welding workstation will rotate the central shaft a second time, so that the worktable equipped with the rear crossbeam lower plate assembly will be rotated to the preparation side, and the rear crossbeam lower plate assembly will be unloaded manually.

[0018] At the same time, another workbench equipped with the rear crossbeam lower plate assembly and the rear crossbeam upper plate is moved to the welding side. Two welding robots weld the rear crossbeam lower plate assembly and the rear crossbeam upper plate accordingly, and weld the left lifting lug and the lifting lug reinforcing plate accordingly, to obtain the rear crossbeam assembly and the left lifting lug assembly respectively.

[0019] S4: The three-axis positioner of the first welding workstation will rotate the central shaft for the third time, so that the other worktable equipped with the rear crossbeam assembly and the left lifting lug assembly will return to the preparation side, and the rear crossbeam assembly and the left lifting lug assembly will be unloaded manually.

[0020] S5: First, place the rear crossbeam assembly, left lug assembly, right lug and two steering gear steel sleeves on one side of the workbench on the preparation side of the second welding workstation, and fix them with several clamping mechanisms;

[0021] Next, place the two sets of energy-absorbing box assemblies, each set including an upper energy-absorbing box plate and a lower energy-absorbing box plate, on the other side of the preparation side workbench, and fix them with several clamping mechanisms.

[0022] S6: The three-axis positioner of the second welding workstation performs the first rotation of the central shaft, so that the workbench equipped with the rear crossbeam assembly one is rotated to the welding side. The two welding robots weld the rear crossbeam assembly one, the lifting lug assembly, the right lifting lug and the two steering gear steel sleeves accordingly, and weld the upper plate and lower plate of the two sets of energy absorption boxes accordingly, to obtain the rear crossbeam assembly two and the two sets of energy absorption boxes respectively.

[0023] At the same time, another welded rear crossbeam assembly, rear suspension mounting bracket and stabilizer bar mounting bracket are placed on another workbench on the preparatory side of the second welding workstation and fixed with several clamping mechanisms.

[0024] S7: After the welding work on the welding side of the second welding workstation is completed and the preparation work on the preparation side of the second welding workstation is completed, the three-axis positioner of the second welding workstation rotates the central shaft for the second time, so that the worktable equipped with the second rear crossbeam assembly and the energy absorption box returns to the preparation side, and the rear crossbeam assembly and the energy absorption box are unloaded manually.

[0025] At the same time, another workbench equipped with the second rear crossbeam assembly, the rear suspension mounting bracket and the stabilizer bar mounting bracket is moved to the welding side, and two welding robots weld the second rear crossbeam assembly, the rear suspension mounting bracket and the stabilizer bar mounting bracket accordingly to obtain the rear crossbeam assembly;

[0026] S8: After the welding work on the welding side of the second welding workstation is completed, the three-axis positioner of the second welding workstation will rotate the central shaft for the third time, so that the other worktable equipped with the rear crossbeam assembly returns to the preparation side, and the rear crossbeam assembly is unloaded manually.

[0027] S9: Place the upper plate and lower plate of the left longitudinal beam on the workbench on the preparation side of the third welding workstation and fix them with several clamping mechanisms;

[0028] S10: The three-axis positioner of the third welding workstation performs the first rotation of the central axis, so that the worktable equipped with the upper plate and lower plate of the left longitudinal beam moves to the welding side. The two welding robots weld the upper plate and lower plate of the left longitudinal beam accordingly to obtain the left longitudinal beam assembly.

[0029] At the same time, the upper plate of the right longitudinal beam and the lower plate of the right longitudinal beam are placed on another workbench on the preparation side of the third welding workstation and fixed with several clamping mechanisms.

[0030] S11: After the welding work on the welding side of the third welding workstation is completed and the preparation work on the preparation side of the third welding workstation is completed, the three-axis positioner of the third welding workstation will rotate the central axis for the second time, so that the worktable equipped with the left longitudinal beam assembly 1 will be rotated to the preparation side, and the left longitudinal beam assembly 1 will be unloaded manually.

[0031] At the same time, another workbench equipped with the upper plate and lower plate of the right longitudinal beam is moved to the welding side, and two welding robots weld the upper plate and lower plate of the right longitudinal beam to obtain the right longitudinal beam assembly.

[0032] S12: After the welding work on the welding side of the third welding workstation is completed, the three-axis positioner of the third welding workstation will rotate the central shaft for the third time, so that the other worktable equipped with the right longitudinal beam assembly will return to the preparation side, and the right longitudinal beam assembly will be unloaded manually.

[0033] S13: First, place the left longitudinal beam assembly, the two composite bushings, and the two swing arm front mounting steel sleeves on one side of the workbench on the preparation side of the fourth welding workstation, and fix them with several clamping mechanisms.

[0034] Then place the right longitudinal beam assembly, the two composite bushings, and the two swing arm front mounting steel sleeves on the other side of the preparatory workbench of the fourth welding workstation, and fix them with several clamping mechanisms.

[0035] S14: The three-axis positioner of the fourth welding workstation performs the first rotation of the central axis, so that the worktable equipped with the left longitudinal beam assembly and the right longitudinal beam assembly are rotated to the welding side. The two welding robots weld the left longitudinal beam assembly, the two composite bushings and the two front mounting steel sleeves of the swing arms accordingly, and weld the right longitudinal beam assembly, the two composite bushings and the two front mounting steel sleeves of the swing arms accordingly, to obtain the left longitudinal beam assembly and the right longitudinal beam assembly respectively.

[0036] At the same time, another welded left longitudinal beam assembly, another welded right longitudinal beam assembly, front crossbeam and rear crossbeam assembly are placed on another workbench of the fourth welding workstation and fixed with several clamping mechanisms.

[0037] S15: After the welding work on the welding side of the fourth welding workstation is completed and the preparation work on the preparation side of the fourth welding workstation is completed, the three-axis positioner of the fourth welding workstation will rotate the central shaft a second time to return the worktable containing the left longitudinal beam assembly and the right longitudinal beam assembly to the preparation side, and the left longitudinal beam assembly and the right longitudinal beam assembly will be unloaded manually.

[0038] At the same time, another workbench equipped with the left longitudinal beam assembly, right longitudinal beam assembly, front crossbeam and rear crossbeam assembly is moved to the welding side, and two welding robots weld the left longitudinal beam assembly, right longitudinal beam assembly, front crossbeam and rear crossbeam assembly accordingly to obtain the first front subframe assembly.

[0039] S16: After the welding work on the welding side of the fourth welding workstation is completed, the three-axis positioner of the fourth welding workstation will rotate the central shaft for the third time, so that the other workbench equipped with the front subframe assembly 1 returns to the preparation side, and the front subframe assembly 1 is unloaded manually.

[0040] S17: Place the front subframe assembly and the two energy-absorbing boxes on the preparatory side of the fifth welding station and fix them with several clamping mechanisms.

[0041] S18: The three-axis positioner of the fifth welding workstation performs the first rotation of the central shaft, so that the worktable equipped with the first front subframe assembly and the energy absorption box is rotated to the welding side. Two welding robots weld the first front subframe assembly and the two energy absorption boxes accordingly to obtain the finished product - the front subframe.

[0042] S19: At the same time, repeat steps S17 and S18 on another workbench located on the preparation side of the fifth welding workstation.

[0043] Further, in step S18, the front subframe, the front crossbeam, the left longitudinal beam assembly, the right longitudinal beam assembly, and the rear crossbeam assembly are sequentially welded to form a closed isosceles trapezoid, and the length of the front crossbeam is greater than the length of the rear crossbeam assembly. The left longitudinal beam assembly and the right longitudinal beam assembly both extend from the rear crossbeam assembly, and a stabilizer bar mounting bracket is welded between the extended portion and the rear crossbeam assembly.

[0044] A rear suspension mounting bracket is welded to the lower side wall of the rear crossbeam assembly. The rear suspension mounting bracket is close to the left longitudinal beam assembly. A right hanger rod is welded between the rear suspension mounting bracket and the rear crossbeam assembly. A left hanger rod assembly is welded to the side of the right hanger rod facing the right longitudinal beam assembly.

[0045] The lower sidewall of the rear crossbeam assembly has a first hole at each end of one side. The first hole penetrates the rear crossbeam assembly and a steering gear steel sleeve is welded inside. This side is away from the stabilizer bar mounting bracket. Each first hole has a corresponding second hole on the side facing the stabilizer bar mounting bracket. The second hole penetrates the rear crossbeam assembly.

[0046] Both ends of the left longitudinal beam assembly and the right longitudinal beam assembly are provided with a third hole, which penetrates the left longitudinal beam assembly and has a composite bushing welded inside. The middle of the left longitudinal beam assembly and the middle of the right longitudinal beam assembly are provided with two fourth holes, which penetrate the left longitudinal beam assembly and have a swing arm front mounting steel sleeve welded inside.

[0047] Both the left longitudinal beam assembly and the right longitudinal beam assembly are provided with a swing arm mounting groove on the side facing the rear cross beam assembly, and the swing arm mounting groove is adjacent to the stabilizer bar mounting bracket.

[0048] An energy-absorbing box is welded to one side wall of both the left and right longitudinal beam assemblies facing the front crossbeam.

[0049] Furthermore, the first welding workstation in steps S1-S4 has a clamping mechanism on its worktable equipped with the rear crossbeam lower plate assembly, which includes two A10 positioning mechanisms, two A11 clamping mechanisms, one A12 clamping mechanism, and one A10 auxiliary support mechanism.

[0050] The clamping mechanism on another workbench, which is equipped with the rear crossbeam assembly and the left lifting lug assembly, includes two A20 positioning mechanisms, two A21 clamping mechanisms, one A22 clamping mechanism, one A23 clamping mechanism, and four A20 side-top mechanisms.

[0051] Each first hole in the lower plate of the rear crossbeam is provided with a positioning mechanism A10; a clamping mechanism A11 is provided on the opposite side of each of the two positioning mechanisms A10, which is used to clamp the lower plate of the rear crossbeam; the clamping mechanism A12 is used to clamp the reinforcing plate to the lower plate of the rear crossbeam; the outer bottom wall of the lower plate of the rear crossbeam is provided with an auxiliary support mechanism A10 corresponding to the position of the reinforcing plate.

[0052] Each first hole of the rear crossbeam assembly is provided with a positioning mechanism of type A20; each clamping mechanism of type A21 is provided with a second hole of the rear crossbeam assembly, and then clamps the rear crossbeam assembly; the clamping mechanism of type A22 is used to clamp the middle part of the rear crossbeam assembly; each end of the two side walls of the rear crossbeam assembly is provided with a side top mechanism of type A20; the clamping mechanism of type A23 is used to clamp the left lifting lug and the lifting lug reinforcing plate accordingly.

[0053] Furthermore, the second welding workstation in steps S5-S8 has a clamping mechanism on its worktable equipped with the rear crossbeam assembly and the energy absorption box, which includes two B10 positioning mechanisms, two B11 clamping mechanisms, two B12 clamping mechanisms, one B13 clamping mechanism, one B14 clamping mechanism, and two B15 clamping mechanisms.

[0054] The clamping mechanism on another workbench equipped with the rear crossbeam assembly includes two B20 positioning mechanisms, two B21 clamping mechanisms, two B22 clamping mechanisms, and one B23 clamping mechanism.

[0055] Each first hole of the second rear crossbeam assembly is provided with a B10 positioning mechanism; each B11 clamping mechanism is used to clamp a steering gear steel sleeve to the first hole of the second rear crossbeam assembly; each B12 clamping mechanism is provided with a second hole of the second rear crossbeam assembly and clamps the second rear crossbeam assembly; the B13 clamping mechanism is used to clamp the right hanger rod to the first rear crossbeam assembly; the B14 clamping mechanism is used to clamp the left hanger rod assembly to the first rear crossbeam assembly; each B15 clamping mechanism is used to clamp the upper plate and lower plate of the energy absorption box.

[0056] Each first hole of the rear crossbeam assembly is provided with a B20 positioning mechanism; each B21 clamping mechanism is provided with a second hole of the rear crossbeam assembly and clamps the rear crossbeam assembly; the B22 clamping mechanism is provided with clamping a stabilizer bar mounting bracket; and each B23 clamping mechanism is provided with clamping the rear suspension mounting bracket with the rear crossbeam assembly.

[0057] Furthermore, the clamping mechanism on the workbench of the third welding workstation in steps S9-S12, which is equipped with the left longitudinal beam assembly, includes two C10 positioning mechanisms, one C11 clamping mechanism, two C10 pressing mechanisms, and four C10 side-top mechanisms.

[0058] The clamping mechanism on another workbench equipped with the right longitudinal beam assembly includes two C20 positioning mechanisms, one C21 clamping mechanism, two C20 pressing mechanisms, and four C20 side-top mechanisms.

[0059] Each of the C10 clamping mechanisms clamps one of the composite bushings to the corresponding third hole of the left longitudinal beam assembly; each of the C11 clamping mechanisms clamps the middle part of the left longitudinal beam assembly; a first positioning hole is provided between each third hole and the corresponding fourth hole, the first positioning hole penetrating the left longitudinal beam assembly, and a corresponding C10 positioning mechanism is provided in each first positioning hole; a C10 side-top mechanism is provided at both ends of the two side walls of the middle part of the left longitudinal beam assembly;

[0060] Each of the C20 clamping mechanisms clamps one of the composite bushings to the corresponding third hole of the right longitudinal beam assembly; the C21 clamping mechanism is used to clamp the middle part of the right longitudinal beam assembly; a second positioning hole is provided between each third hole and the corresponding fourth hole, the second positioning hole penetrates the right longitudinal beam assembly, and a C20 positioning mechanism is provided in each second positioning hole; a C20 side-top mechanism is provided at both ends of the two side walls of the middle part of the right longitudinal beam assembly.

[0061] Furthermore, in the fourth welding workstation of steps S13-16, the clamping mechanism on the worktable equipped with the left longitudinal beam assembly and the right longitudinal beam assembly includes four D11 positioning mechanisms, two D11 auxiliary support mechanisms, two D11 clamping mechanisms, two D12 clamping mechanisms, four D13 clamping mechanisms, and two D14 clamping mechanisms; the D11 clamping mechanism includes a D111 clamping part and a D112 clamping part;

[0062] Each third hole of the left longitudinal beam assembly is provided with a positioning mechanism D11. The clamping part D111 corresponds to the third hole adjacent to the swing arm mounting slot and clamps the left longitudinal beam assembly. A support mechanism D11 extends into the swing arm mounting slot. The clamping part D112 corresponds to the support mechanism D11 and clamps one wall of the swing arm mounting slot. The clamping mechanism D12 corresponds to another third hole away from the swing arm mounting slot and clamps the left longitudinal beam assembly. Two clamping mechanisms D13 are used to clamp the steering gear sleeve to the corresponding fourth hole. A clamping mechanism D14 is provided between the clamping mechanisms D12 and D13, and this clamping mechanism D14 is used to clamp the left longitudinal beam assembly.

[0063] Each third hole of the right longitudinal beam assembly is provided with a positioning mechanism D11. The clamping part D111 corresponds to the third hole adjacent to the swing arm mounting slot and clamps the right longitudinal beam assembly. A support mechanism D11 extends into the swing arm mounting slot. The clamping part D112 corresponds to the support mechanism D11 and clamps one wall of the swing arm mounting slot. The clamping mechanism D12 corresponds to another third hole away from the swing arm mounting slot and clamps the right longitudinal beam assembly. Two clamping mechanisms D13 are used to clamp the steering gear sleeve to the corresponding fourth hole. A clamping mechanism D14 is provided between the clamping mechanisms D12 and D13, and this clamping mechanism D14 is used to clamp the right longitudinal beam assembly.

[0064] Furthermore, in the fourth welding workstation of steps S13-16, the clamping mechanism on another workbench equipped with the front subframe assembly includes four D20 positioning mechanisms, four D21 clamping mechanisms, two D22 clamping mechanisms, two D23 clamping mechanisms, two D24 clamping mechanisms, and two D25 clamping mechanisms.

[0065] Each third hole of the front subframe assembly is provided with a positioning mechanism of type D20, and each positioning mechanism of type D20 is matched with a clamping mechanism of type D21. The clamping mechanism of type D21 is used to clamp the left longitudinal beam assembly and the right longitudinal beam assembly respectively. Each clamping mechanism of type D22 corresponds to the first hole and the second hole on both sides of the rear crossbeam assembly and clamps the rear crossbeam assembly. Each side of the front crossbeam near the third hole is provided with a clamping mechanism of type D23 to clamp the front crossbeam. The middle part of the left longitudinal beam assembly and the right longitudinal beam assembly are respectively provided with a clamping mechanism of type D24 to clamp the corresponding left longitudinal beam assembly and the right longitudinal beam assembly. Each clamping mechanism of type D25 clamps a stabilizer bar mounting bracket.

[0066] Furthermore, in the fifth welding workstation of steps S17-19, both workstations are equipped with a front subframe. The clamping mechanism of the two workstations includes four E11 positioning mechanisms, four E11 clamping mechanisms, and two E12 clamping mechanisms. Each E11 clamping mechanism includes an E111 positioning part and an E111 clamping part.

[0067] Each third hole of the front subframe corresponds to an E11 positioning mechanism, and each E11 positioning mechanism is matched with an E11 clamping mechanism, which is used to clamp the front subframe; each E12 clamping mechanism clamps an energy-absorbing device.

[0068] Implementing the embodiments of the present invention will have the following beneficial effects:

[0069] This invention proposes a welding production line for automotive front subframes. The three-axis positioners in each welding workstation can rotate the fixtures from the preparation side to the welding side, or vice versa, ensuring that the loading and welding cycles of each welding workstation are independent and do not interfere with each other, thereby improving welding efficiency. This invention also proposes a method for producing automotive front subframes, dividing the welding steps between the various parts of the front subframe into nine sequences, rationally allocating the welding workload of each sequence, reducing the welding time for welding one front subframe, and improving welding efficiency. Attached Figure Description

[0070] Figure 1 This is a top view of the welding workstation in this application;

[0071] Figure 2 This is a top view of the automotive front subframe welding production line described in this application;

[0072] Figure 3 This is a schematic diagram of the welding process for steps S1-S8 in this application;

[0073] Figure 4 This is a schematic diagram of the welding process for steps S9-S15 in this application;

[0074] Figure 5 This is a schematic diagram of the welding process for steps S15-S19 in this application;

[0075] Figure 6 This is a structural schematic diagram of the workbench equipped with the rear crossbeam lower plate assembly in this application.

[0076] Figure 7 This is a structural schematic diagram of the workbench equipped with the rear crossbeam assembly and the left lifting lug assembly of this application.

[0077] Figure 8 This is a schematic diagram of the workbench in this application, which is equipped with the second rear crossbeam assembly and the energy-absorbing box.

[0078] Figure 9 This is a structural schematic diagram of the workbench equipped with the rear crossbeam assembly in this application;

[0079] Figure 10 This is a schematic diagram of the workbench equipped with the left longitudinal beam assembly in this application.

[0080] Figure 11 This is a structural schematic diagram of the workbench equipped with the right longitudinal beam assembly in this application;

[0081] Figure 12 This is a structural schematic diagram of the workbench in this application, which is equipped with the left longitudinal beam assembly and the right longitudinal beam assembly.

[0082] Figure 13 This is a schematic diagram of the workbench equipped with the front subframe assembly in this application.

[0083] Figure 14 This is a schematic diagram of the workbench equipped with the front subframe in this application.

[0084] Figure label:

[0085] 1. Welding workstation; 11. Three-axis positioner; 111. Central axis; 112. Working axis; 12. Fixture; 121. Worktable; 122. Clamping mechanism; 13. Welding robot; 14. First welding workstation; 15. Second welding workstation; 16. Third welding workstation; 17. Fourth welding workstation; 18. Fifth welding workstation; 19. Control panel; 20. Welding control box;

[0086] 2. Front subframe; 21. Rear crossbeam lower plate assembly; 211. Rear crossbeam lower plate; 212. Reinforcing plate; 22. Rear crossbeam upper plate; 23. Rear crossbeam assembly one; 24. Left hanger lug assembly; 241. Left hanger lug; 242. Hanger lug reinforcing plate; 25. Right hanger lug; 26. Steering gear sleeve; 27. Rear crossbeam assembly two; 28. Energy absorption box; 281. Energy absorption box upper plate; 282. Energy absorption box lower plate; 29. ​​Rear suspension mounting bracket; 30. Stabilizer bar mounting bracket; 31. Rear crossbeam assembly; 32. 321. Left longitudinal beam assembly; 322. Left longitudinal beam upper plate; 323. Left longitudinal beam lower plate; 33. Right longitudinal beam assembly; 331. Right longitudinal beam upper plate; 332. Right longitudinal beam lower plate; 34. Composite bushing; 35. Swing arm front mounting steel sleeve; 36. Left longitudinal beam assembly; 37. Right longitudinal beam assembly; 38. Front crossbeam; 39. Front subframe assembly; 40. First hole; 41. Second hole; 42. Third hole; 43. Fourth hole; 44. First positioning hole; 45. Second positioning hole; 46. Swing arm mounting slot;

[0087] 141. Positioning mechanism A10; 142. Clamping mechanism A11; 143. Clamping mechanism A12; 144. A10 auxiliary support mechanism; 145. Positioning mechanism A20; 146. Clamping mechanism A21; 147. Clamping mechanism A22; 148. Clamping mechanism A23; 149. Side support mechanism A20;

[0088] 151. Positioning mechanism B10; 152. Clamping mechanism B11; 153. Clamping mechanism B12; 154. Clamping mechanism B13; 155. Clamping mechanism B14; 156. Clamping mechanism B15; 157. Positioning mechanism B20; 158. Clamping mechanism B21; 159. Clamping mechanism B22; 160. Clamping mechanism B23;

[0089] 161. Positioning mechanism C10; 162. Clamping mechanism C11; 163. Pressing mechanism C10; 164. Side-lifting mechanism C10; 165. Positioning mechanism C20; 166. Clamping mechanism C21; 167. Pressing mechanism C20; 168. Side-lifting mechanism C20;

[0090] 171. Positioning mechanism D11; 172. Auxiliary support mechanism D11; 173. Clamping mechanism D11; 1731. Clamping part D111; 1732. Clamping part D112; 174. Clamping mechanism D12; 175. Clamping mechanism D13; 176. Clamping mechanism D14; 177. Positioning mechanism D20; 178. Clamping mechanism D21; 179. Clamping mechanism D22; 180. Clamping mechanism D23; 181. Clamping mechanism D24; 182. Clamping mechanism D25;

[0091] 183. Positioning mechanism E11; 184. Clamping mechanism E11; 185. Clamping mechanism E12. Detailed Implementation

[0092] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains; the terminology used herein and in the specification of the application is for the purpose of describing particular embodiments only and is not intended to limit the invention. The terms “first,” “second,” etc., in the specification, claims, or the foregoing drawings are used to distinguish different objects and not to describe a particular order.

[0093] See attached document Figure 1-2 The present invention provides a welding production line for a front subframe of an automobile, which includes multiple welding workstations 1, wherein each welding workstation 1 includes a three-axis positioner 11, a fixture 12 and two welding robots 13.

[0094] The three-axis positioner 11 is installed on the bottom wall of the welding workstation 1, and two welding robots 13 are provided on one side of the three-axis positioner 11.

[0095] The three-axis positioner 11 includes a horizontal central axis 111 and two working axes 112 parallel to the central axis 111. The side of the three-axis positioner 11 facing the welding robot 13 is the welding side, and the other side of the three-axis positioner 11 away from the welding robot 13 is the preparation side. The two working axes 112 are symmetrically arranged on both sides of the central axis 111 and rotate around the axial direction of the central axis 111, so that the working axes 112 can rotate from the preparation side to the welding side, or from the welding side to the preparation side.

[0096] The fixture 12 includes a workbench 121 and a plurality of clamping mechanisms 122, wherein the plurality of clamping mechanisms 122 are used to clamp the workpiece to be welded; the plurality of clamping mechanisms 122 are detachably mounted on the workbench 121, or the plurality of clamping mechanisms 122 are fixedly mounted on the workbench 121.

[0097] Both the preparation side and the welding side are rotatably mounted with a worktable 121, which rotates around a corresponding working axis 112. The welding robot 13 is equipped with a welding torch, which is used to weld the workpiece held by the worktable 121 on the welding side. The welding robot 13 adopts an existing multi-axis motion robotic arm, with the welding torch at the front working end of the robotic arm. The welding torch can be moved to the worktable 121 on the welding side of the three-axis positioner 11 for operation.

[0098] In this embodiment, each welding workstation 1 is provided with a control panel 19 on an outer side wall away from the welding robot 13. The control panel 19 is used to control the start and stop of the welding workstation 1. The control panel 19 can also be used to control the omnidirectional rotation of the three-axis positioner 11 and the clamping and resetting of the clamping mechanism 122.

[0099] Each welding workstation 1 has a welding control box 20 on its outer side wall away from the control panel 19. The welding control box 20 is used to control the welding action, welding path, welding sequence, etc. of the welding robot 13. The control panel 19 is electrically connected to the welding control box 20, so the control panel 19 can also control the welding robot 13 to weld the workpiece.

[0100] The workpiece to be welded is placed on the preparatory worktable 121 (i.e., the workpiece is loaded onto the preparatory worktable 121, the same applies throughout the text). Then, the control panel 19 is operated. At this time, the clamping mechanism 122 first clamps the corresponding workpiece to be welded. Then, the three-axis positioner 11 rotates, moving the original preparatory worktable 121 to the welding side. The welding robot 13 then welds the workpiece. During the welding process, the worktable 121 holding the workpiece will also rotate, so that the weld seam of the workpiece is better presented for the welding robot 13 to weld. After welding is completed, the three-axis positioner 11 rotates again. The worktable 121 containing the workpiece to be welded is moved back to the preparation side. Then, the welded workpiece is unloaded manually and a new workpiece to be welded is placed on it. While the worktable 121 on the welding side is performing welding work, another workpiece to be welded is placed on and clamped on the preparation side at the same time. This allows the worker to unload the welded workpiece on one worktable 121 while the workpiece to be welded on the other worktable 121 is being welded on the welding side. This makes the workpiece loading cycle and the welding cycle independent and do not affect each other, thus improving the welding efficiency of the welding workstation 1.

[0101] See attached document Figure 2The welding workstation 1 comprises five stations, which are arranged and assembled along the axial direction of the triaxial positioner 11, namely, the first welding workstation 14, the second welding workstation 15, the third welding workstation 16, the fourth welding workstation 17, and the fifth welding workstation 18. This arrangement of the welding workstations 1 reduces worker walking time and workpiece transfer time, thereby improving worker efficiency and welding efficiency of the welding workstations 1.

[0102] This invention also provides a method for producing a front subframe of an automobile using the aforementioned automotive front subframe welding production line. (See attached diagram.) Figure 3-14 As one embodiment, a method for producing a front subframe of an automobile, applied to the aforementioned automobile front subframe welding production line, includes the following steps:

[0103] S1: Place the lower plate 211 of the rear crossbeam and the reinforcing plate 212 on the workbench 121 on the preparatory side of the first welding workstation 14, and fix them with several clamping mechanisms 122.

[0104] S2: The three-axis positioner 11 of the first welding workstation 14 performs the first rotation of the central shaft 111, so that the worktable 121 equipped with the rear crossbeam lower plate 211 and the reinforcing plate 212 is rotated to the welding side. The two welding robots 13 weld the reinforcing plate 212 and the rear crossbeam lower plate 211 accordingly to obtain the rear crossbeam lower plate assembly 21.

[0105] Meanwhile, another welded rear crossbeam lower plate assembly 21 and rear crossbeam upper plate 22 are placed on another workbench 121 on the preparatory side of the first welding workstation 14 and fixed with several clamping mechanisms 122; then the left lifting lug 241 and lifting lug reinforcing plate 242 are placed on the other side of the other workbench 121 of the first welding workstation 14 and fixed with several clamping mechanisms 122.

[0106] S3: After the welding work on the welding side of the first welding workstation 14 is completed and the preparation work on the preparation side of the first welding workstation 14 is completed, the three-axis positioner 11 of the first welding workstation 14 will rotate the central shaft 111 for the second time, so that the worktable 121 equipped with the rear crossbeam lower plate assembly 21 will be rotated to the preparation side, and the rear crossbeam lower plate assembly 21 will be unloaded manually.

[0107] At the same time, another workbench 121 equipped with the rear crossbeam lower plate assembly 21 and the rear crossbeam upper plate 22 is moved to the welding side. Two welding robots 13 weld the rear crossbeam lower plate assembly 21 and the rear crossbeam upper plate 22 accordingly, and weld the left lifting lug 241 and the lifting lug reinforcing plate 242 accordingly, to obtain the rear crossbeam assembly 23 and the left lifting lug assembly 24 respectively.

[0108] S4: The three-axis positioner 11 of the first welding workstation 14 rotates the central shaft 111 for the third time, so that the other worktable 121, which is equipped with the rear crossbeam assembly 23 and the left lifting lug assembly 24, returns to the preparation side, and the rear crossbeam assembly 23 and the left lifting lug assembly 24 are unloaded manually.

[0109] S5: First, place the rear crossbeam assembly 23, the left lifting lug assembly 24, the right lifting lug 25 and the two steering gear steel sleeves 26 on one side of the workbench 121 on the preparation side of the second welding workstation 15, and fix them with several clamping mechanisms 122.

[0110] Next, place the two sets of energy-absorbing box 28 components, each set including an upper energy-absorbing box plate 281 and a lower energy-absorbing box plate 282, on the other side of the preparation side workbench 121, and fix them with several clamping mechanisms 122.

[0111] S6: The three-axis positioner 11 of the second welding workstation 15 performs the first rotation of the central shaft 111, so that the worktable 121 equipped with the rear crossbeam assembly 23 is rotated to the welding side. The two welding robots 13 weld the rear crossbeam assembly 23, the lifting lug assembly, the right lifting lug 25 and the two steering gear steel sleeves 26 accordingly, and weld the upper plate 281 and the lower plate 282 of the two sets of energy-absorbing boxes accordingly, so as to obtain the second rear crossbeam assembly 27 and the two sets of energy-absorbing boxes 28 respectively.

[0112] At the same time, another welded rear crossbeam assembly 27, rear suspension mounting bracket 29 and stabilizer bar mounting bracket 30 are placed on another workbench 121 on the preparatory side of the second welding workstation 15 and fixed with several clamping mechanisms 122.

[0113] S7: After the welding work on the welding side of the second welding workstation 15 is completed and the preparation work on the preparation side of the second welding workstation 15 is completed, the three-axis positioner 11 of the second welding workstation 15 performs a second rotation of the central shaft 111, so that the worktable 121 equipped with the rear crossbeam assembly 27 and the energy absorption box 28 returns to the preparation side, and the rear crossbeam assembly 27 and the energy absorption box 28 are unloaded manually.

[0114] Meanwhile, another workbench 121, equipped with the second rear crossbeam assembly 27, the rear suspension mounting bracket 29, and the stabilizer bar mounting bracket 30, is moved to the welding side. Two welding robots 13 weld the second rear crossbeam assembly 27, the rear suspension mounting bracket 29, and the stabilizer bar mounting bracket 30 to obtain the rear crossbeam assembly 31.

[0115] S8: After the welding work on the welding side of the second welding workstation 15 is completed, the three-axis positioner 11 of the second welding workstation 15 will rotate the central shaft 111 for the third time, so that the other worktable 121 equipped with the rear crossbeam assembly 31 returns to the preparation side, and the rear crossbeam assembly 31 is unloaded manually.

[0116] S9: Place the upper plate 321 and the lower plate 322 of the left longitudinal beam on the workbench 121 on the preparation side of the third welding workstation 16, and fix them with several clamping mechanisms 122.

[0117] S10: The three-axis positioner 11 of the third welding workstation 16 performs the first rotation of the central shaft 111, so that the worktable 121 equipped with the upper plate 321 and the lower plate 322 of the left longitudinal beam is rotated to the welding side. The two welding robots 13 weld the upper plate 321 and the lower plate 322 of the left longitudinal beam accordingly to obtain the left longitudinal beam assembly 32.

[0118] At the same time, the upper plate 331 and the lower plate 332 of the right longitudinal beam are placed on another workbench 121 on the preparation side of the third welding workstation 16, and fixed with several clamping mechanisms 122.

[0119] S11: After the welding work on the welding side of the third welding workstation 16 is completed and the preparation work on the preparation side of the third welding workstation 16 is completed, the three-axis positioner 11 of the third welding workstation 16 will rotate the central shaft 111 for the second time, so that the worktable 121 equipped with the left longitudinal beam assembly 32 will be rotated to the preparation side, and the left longitudinal beam assembly 32 will be unloaded manually.

[0120] At the same time, another workbench 121, which is equipped with the upper plate 331 and the lower plate 332 of the right longitudinal beam, is moved to the welding side, and two welding robots 13 weld the upper plate 331 and the lower plate 332 of the right longitudinal beam accordingly to obtain the right longitudinal beam assembly 33.

[0121] S12: After the welding work on the welding side of the third welding workstation 16 is completed, the three-axis positioner 11 of the third welding workstation 16 will rotate the central shaft 111 for the third time, so that the other worktable 121 equipped with the right longitudinal beam assembly 33 returns to the preparation side, and the right longitudinal beam assembly 33 is unloaded manually.

[0122] S13: First, place the left longitudinal beam assembly 32, the two composite bushings 34 and the two swing arm front mounting steel sleeves 35 on one side of the workbench 121 on the preparation side of the fourth welding workstation 17, and fix them with several clamping mechanisms 122.

[0123] Then, place the right longitudinal beam assembly 33, the two composite bushings 34 and the two swing arm front mounting steel sleeves 35 on the other side of the workbench 121 on the preparatory side of the fourth welding workstation 17, and fix them with several clamping mechanisms 122.

[0124] S14: The three-axis positioner 11 of the fourth welding workstation 17 performs the first rotation of the central shaft 111, so that the worktable 121 equipped with the left longitudinal beam assembly 32 and the right longitudinal beam assembly 33 is rotated to the welding side. The two welding robots 13 weld the left longitudinal beam assembly 32, the two composite bushings 34 and the two swing arm front mounting steel sleeves 35 respectively, and weld the right longitudinal beam assembly 33, the two composite bushings 34 and the two swing arm front mounting steel sleeves 35 respectively, to obtain the left longitudinal beam assembly 36 and the right longitudinal beam assembly 37 respectively.

[0125] Meanwhile, another welded left longitudinal beam assembly 36, another welded right longitudinal beam assembly 37, front crossbeam 38 and rear crossbeam assembly 31 are placed on another workbench 121 of the fourth welding workstation and fixed with several clamping mechanisms 122.

[0126] S15: After the welding work on the welding side of the fourth welding workstation 17 is completed and the preparation work on the preparation side of the fourth welding workstation 17 is completed, the three-axis positioner 11 of the fourth welding workstation 17 will rotate the central shaft 111 for the second time, so that the worktable 121 equipped with the left longitudinal beam assembly 36 and the right longitudinal beam assembly 37 returns to the preparation side, and the left longitudinal beam assembly 36 and the right longitudinal beam assembly 37 are unloaded manually.

[0127] At the same time, another workbench 121 equipped with the left longitudinal beam assembly 36, the right longitudinal beam assembly 37, the front crossbeam 38 and the rear crossbeam assembly 31 is moved to the welding side, and two welding robots 13 weld the left longitudinal beam assembly 36, the right longitudinal beam assembly 37, the front crossbeam 38 and the rear crossbeam assembly 31 accordingly to obtain the front subframe assembly 39.

[0128] S16: After the welding work on the welding side of the fourth welding workstation 17 is completed, the three-axis positioner 11 of the fourth welding workstation 17 will rotate the central shaft 111 for the third time, so that the other worktable 121 equipped with the front subframe assembly 39 returns to the preparation side, and the front subframe assembly 39 is unloaded manually.

[0129] S17: Place the front subframe assembly 39 and the two energy-absorbing boxes 28 on the preparatory side workbench 121 of the fifth welding workstation 18, and fix them with several clamping mechanisms 122.

[0130] S18: The three-axis positioner 11 of the fifth welding workstation 18 performs the first rotation of the central shaft 111, so that the worktable 121 equipped with the front subframe assembly 39 and the energy absorption box 28 is rotated to the welding side. The two welding robots 13 weld the front subframe assembly 39 and the two energy absorption boxes 28 accordingly to obtain the finished product - the front subframe 2.

[0131] S19: At the same time, another workbench 121 located on the preparation side of the fifth welding workstation 18 repeats steps S17 and S18.

[0132] In this embodiment, the welding steps between the various parts of the front subframe 2 are divided into nine sequences:

[0133] The first welding sequence generates the lower crossbeam assembly 21; the second welding sequence generates the first crossbeam assembly 23 and the left hanger rod assembly 24; the third welding sequence generates the second crossbeam assembly 27 and the energy-absorbing box 28; the fourth welding sequence generates the crossbeam assembly 31; the fifth welding sequence generates the first left longitudinal beam assembly 32; the sixth welding sequence generates the first right longitudinal beam assembly 33; the seventh welding sequence generates the first left longitudinal beam assembly 36 and the second right longitudinal beam assembly 37; the eighth welding sequence generates the first front subframe assembly 39; the ninth welding sequence generates the finished product – the front subframe 2.

[0134] The welding sequence of the present invention is as follows: the rear crossbeam lower plate assembly 21 of the first sequence is then put into the second sequence; the rear crossbeam assembly 23 of the second sequence and the left hanger rod assembly 24 of the second sequence are then put into the third sequence; the rear crossbeam assembly 27 of the third sequence is then put into the fourth sequence; the left longitudinal beam assembly 32 of the fifth sequence and the right longitudinal beam assembly 33 of the sixth sequence are then put into the seventh sequence; the rear crossbeam assembly 31 of the fourth sequence, the left longitudinal beam assembly 36 of the seventh sequence and the right longitudinal beam assembly 37 of the seventh sequence are then put into the eighth sequence; and the energy-absorbing box 28 of the third sequence and the front subframe assembly 39 of the eighth sequence are then put into the ninth sequence.

[0135] This invention divides the welding steps between the various parts of the front subframe 2 into nine sequences, rationally allocates the welding workload of each sequence, reduces the welding time of welding a finished front subframe 2, and improves its welding efficiency.

[0136] See attached document Figure 3-5 In this embodiment, the front subframe 2 (i.e., the finished product) mentioned in step S18, the front crossbeam 38, the left longitudinal beam assembly 36, the right longitudinal beam assembly 37 and the rear crossbeam assembly 31 are sequentially welded to form a closed isosceles trapezoid, and the length of the front crossbeam 38 is greater than the length of the rear crossbeam assembly 31. The left longitudinal beam assembly 36 and the right longitudinal beam assembly 37 both extend from the rear crossbeam assembly 31, and a stabilizer bar mounting bracket 30 is welded between the extended portion and the rear crossbeam assembly 31.

[0137] A rear suspension mounting bracket 29 is welded to the lower side wall of the rear crossbeam assembly 31. The rear suspension mounting bracket 29 is close to the left longitudinal beam assembly 36. A right hanger rod 25 is welded between the rear suspension mounting bracket 29 and the rear crossbeam assembly 31. A left hanger rod assembly 24 is welded to the side of the right hanger rod 25 facing the right longitudinal beam assembly 37.

[0138] The rear crossbeam assembly 31 has a first hole 40 at each end of one side of its lower sidewall. The first hole 40 penetrates the rear crossbeam assembly 31 and has a steering gear steel sleeve 26 welded inside. This side is away from the stabilizer bar mounting bracket 30. Each first hole 40 has a corresponding second hole 41 on the side facing the stabilizer bar mounting bracket 30. The second hole 41 penetrates the rear crossbeam assembly 31.

[0139] Both ends of the left longitudinal beam assembly 36 and the right longitudinal beam assembly 37 are provided with a third hole 42, which penetrates the left longitudinal beam assembly 36 and has a composite bushing 34 welded inside. The middle of the left longitudinal beam assembly 36 and the middle of the right longitudinal beam assembly 37 are provided with two fourth holes 43, which penetrate the left longitudinal beam assembly 36 and have a swing arm front mounting steel sleeve 35 welded inside.

[0140] Both the left longitudinal beam assembly 36 and the right longitudinal beam assembly 37 are provided with a swing arm mounting groove 46 on the side facing the rear crossbeam assembly 31, and the swing arm mounting groove 46 is adjacent to the stabilizer bar mounting bracket 30.

[0141] An energy-absorbing box 28 is welded to one side wall of both the left longitudinal beam assembly 36 and the right longitudinal beam assembly 37 facing the front crossbeam 38.

[0142] See attached document Figure 6-7 The first welding workstation 14 in steps S1-S4 has a clamping mechanism 122 on its workbench 121 equipped with the rear crossbeam lower plate assembly 21, which includes two A10 positioning mechanisms 141, two A11 clamping mechanisms 142, one A12 clamping mechanism 143, and one A10 auxiliary support mechanism 144.

[0143] The clamping mechanism 122 on another workbench 121, which is equipped with the rear crossbeam assembly 23 and the left lifting lug assembly 24, includes two A20 positioning mechanisms 145, two A21 clamping mechanisms 146, one A22 clamping mechanism 147, one A23 clamping mechanism 148, and four A20 side-top mechanisms 149.

[0144] Each first hole 40 of the lower rear crossbeam plate 211 is provided with a positioning mechanism 141 of type A10; a clamping mechanism 142 of type A11 is provided on the opposite side of each of the two positioning mechanisms 141 of type A10, which is used to clamp the lower rear crossbeam plate 211; a clamping mechanism 143 of type A12 is used to clamp the reinforcing plate 212 to the lower rear crossbeam plate 211; an auxiliary support mechanism 144 of type A10 is provided on the outer bottom wall of the lower rear crossbeam plate 211 corresponding to the position of the reinforcing plate 212. This is to prevent the reinforcing plate 212 from loosening or even falling off during the welding process of the lower rear crossbeam plate 211 to form the lower rear crossbeam plate assembly 21, which would affect the welding quality of the lower rear crossbeam plate assembly 211.

[0145] Each first hole 40 of the rear crossbeam assembly 23 is provided with a positioning mechanism 145 of type A20; each clamping mechanism 146 of type A21 is provided with a second hole 41 of the rear crossbeam assembly 23, and then clamps the rear crossbeam assembly 23; the clamping mechanism 147 of type A22 is used to clamp the middle part of the rear crossbeam assembly 23; each end of the two side walls of the rear crossbeam assembly 23 is provided with a side top mechanism 149 of type A20; the clamping mechanism 148 of type A23 is used to clamp the left lifting lug 241 and the lifting lug reinforcing plate 242 respectively. To prevent loosening or even falling off during the welding process of the rear crossbeam lower plate assembly 21 and the rear crossbeam upper plate 22 to form the rear crossbeam assembly 23, the left lifting lug 241 and the lifting lug reinforcing plate 242 to form the left lifting lug assembly 24, which would affect the welding quality of the rear crossbeam assembly 23 and the left lifting lug assembly 24.

[0146] See attached document Figure 8-9 The second welding workstation 15 in steps S5-S8 has a clamping mechanism 122 on its workbench 121, which is equipped with the rear crossbeam assembly 27 and the energy absorption box 28. This mechanism includes two B10 positioning mechanisms 151, two B11 clamping mechanisms 152, two B12 clamping mechanisms 153, one B13 clamping mechanism 154, one B14 clamping mechanism 155, and two B15 clamping mechanisms 156.

[0147] The clamping mechanism 122 on another worktable 121, which is equipped with the rear crossbeam assembly 31, includes two B20 positioning mechanisms 157, two B21 clamping mechanisms 158, two B22 clamping mechanisms 159, and one B23 clamping mechanism 160.

[0148] Each first hole 40 of the second rear crossbeam assembly 27 is provided with a B10 positioning mechanism 151; each B11 clamping mechanism 152 is used to clamp a steering gear steel sleeve 26 to the first hole 40 of the second rear crossbeam assembly 27; each B12 clamping mechanism 153 is respectively corresponding to a second hole 41 of the second rear crossbeam assembly 27, and then clamps the second rear crossbeam assembly 27; each B13 clamping mechanism 154 is used to clamp the right hanger rod 25 to the first rear crossbeam assembly 23; each B14 clamping mechanism 155 is used to clamp the left hanger rod assembly 24 to the first rear crossbeam assembly 23; each B15 clamping mechanism 156 is used to clamp the upper plate 281 and the lower plate 282 of the energy absorption box. To prevent the rear crossbeam assembly 23, left hanger rod assembly 24, right hanger rod 25 and two steering gear steel sleeves 26 from loosening or even falling off during the welding process of the corresponding components to form the rear crossbeam assembly 27, the upper plate 281 of the energy-absorbing box and the lower plate 282 of the energy-absorbing box, and to prevent them from affecting the welding quality of the rear crossbeam assembly 27 and the energy-absorbing box 28.

[0149] Each first hole 40 of the rear crossbeam assembly 31 is provided with a positioning mechanism 157 of type B20; each clamping mechanism 158 of type B21 corresponds to a second hole 41 of the rear crossbeam assembly 31, and clamps the rear crossbeam assembly 27; the clamping mechanism 159 of type B22 is used to clamp one of the stabilizer bar mounting brackets 30; each clamping mechanism 160 of type B23 is used to clamp the rear suspension mounting bracket 29 to the rear crossbeam assembly 27. This prevents the rear crossbeam assembly 27, the rear suspension mounting bracket 29 and the stabilizer bar mounting bracket 30 from loosening or even falling off during the welding process to form the rear crossbeam assembly 31, which would affect the welding quality of the rear crossbeam assembly 31.

[0150] See attached document Figure 10-11 The third welding workstation 16 in steps S9-S12 has a clamping mechanism 122 on the workbench 121 equipped with the left longitudinal beam assembly 32, which includes two C10 positioning mechanisms 161, one C11 clamping mechanism 162, two C10 pressing mechanisms 163 and four C10 side-top mechanisms 164.

[0151] The clamping mechanism 122 on another worktable 121, which is equipped with the right longitudinal beam assembly 33, includes two C20 positioning mechanisms 165, one C21 clamping mechanism 166, two C20 pressing mechanisms 167, and four C20 side-top mechanisms 168.

[0152] Each of the C10 clamping mechanisms 163 clamps a composite bushing 34 to a corresponding third hole 42 of a left longitudinal beam assembly 32; each of the C11 clamping mechanisms 162 clamps the middle part of the left longitudinal beam assembly 32; a first positioning hole 44 is provided between each third hole 42 and the corresponding fourth hole 43, the first positioning hole 44 penetrating the left longitudinal beam assembly 32, and a corresponding C10 positioning mechanism 161 is provided in each first positioning hole 44; a C10 side-top mechanism 164 is provided at both ends of the two side walls of the middle part of the left longitudinal beam assembly 32. This prevents loosening or even falling off during the welding of the upper plate 321 and the lower plate 322 of the left longitudinal beam to form the left longitudinal beam assembly 32, thus affecting the welding quality of the left longitudinal beam assembly 32.

[0153] Each of the C20 clamping mechanisms 167 clamps a composite bushing 34 to a corresponding third hole 42 of a right longitudinal beam assembly 33; the C21 clamping mechanism 166 clamps the middle part of the right longitudinal beam assembly 33; a second positioning hole 45 is provided between each third hole 42 and the corresponding fourth hole 43, the second positioning hole 45 penetrates the right longitudinal beam assembly 33, and a corresponding C20 positioning mechanism 165 is provided in each second positioning hole 45; a C20 side-top mechanism 168 is provided at both ends of the two side walls of the middle part of the right longitudinal beam assembly 33. This prevents loosening or even falling off during the welding of the upper right longitudinal beam plate 331 and the lower right longitudinal beam plate 332 to form the right longitudinal beam assembly 33, thus affecting the welding quality of the right longitudinal beam assembly 33.

[0154] See attached document Figure 12 The fourth welding workstation 17 in steps S13-16 has a clamping mechanism 122 on its workbench 121, which is equipped with the left longitudinal beam assembly 36 and the right longitudinal beam assembly 37. This mechanism includes four D11 positioning mechanisms 171, two D11 auxiliary support mechanisms 172, two D11 clamping mechanisms 173, two D12 clamping mechanisms 174, four D13 clamping mechanisms 175, and two D14 clamping mechanisms 176. The D11 clamping mechanism 173 includes a D111 clamping part 1731 and a D112 clamping part 1732.

[0155] Each third hole 42 of the left longitudinal beam assembly 32 is provided with a positioning mechanism 171 of number D111. The clamping part 1731 of number D111 corresponds to the third hole 42 adjacent to the swing arm mounting groove 46 and clamps the left longitudinal beam assembly 32. A support mechanism 172 of number D111 extends into the swing arm mounting groove 46. The clamping part 1732 of number D112 corresponds to the support mechanism 172 of number D111 and clamps one wall of the swing arm mounting groove 46. The D12 clamping mechanism 174, corresponding to another third hole 42 away from the swing arm mounting slot 46, clamps the left longitudinal beam assembly 32. Two D13 clamping mechanisms 175 are used to clamp the steering gear sleeve 26 to the corresponding fourth hole 43. A D14 clamping mechanism 176 is provided between the D12 and D13 clamping mechanisms 174 and is used to clamp the left longitudinal beam assembly 32. This prevents the left longitudinal beam assembly 32, the two composite bushings 34, and the two swing arm front mounting sleeves 35 from loosening or even falling off during the welding process to form the left longitudinal beam assembly 36 and the right longitudinal beam assembly 37, thus affecting the welding quality of the left longitudinal beam assembly 36.

[0156] Each third hole 42 of the right longitudinal beam assembly 33 is provided with a positioning mechanism 171 of number D111. The clamping part 1731 of number D111 corresponds to the third hole 42 adjacent to the swing arm mounting groove 46 and clamps the right longitudinal beam assembly 33. A support mechanism 177 of number D111 extends into the swing arm mounting groove 46. The clamping part 1732 of number D112 corresponds to the support mechanism 177 of number D111 and clamps one wall of the swing arm mounting groove 46. Clamping mechanism 174, corresponding to a third hole 42 away from the swing arm mounting slot 46, clamps the right longitudinal beam assembly 33. Two clamping mechanisms 175, designated D13, clamp the steering gear sleeve 26 to the corresponding fourth hole 43. A clamping mechanism 176, designated D14, is provided between clamping mechanisms 174 and D13, clamping the right longitudinal beam assembly 33. This prevents loosening or even falling off during the welding process of the right longitudinal beam assembly 33, the two composite bushings 34, and the two swing arm front mounting sleeves 35 to form the right longitudinal beam assembly 37, thus affecting the welding quality of the right longitudinal beam assembly 37.

[0157] See attached document Figure 13The fourth welding workstation 17 in steps S13-16 has a clamping mechanism 122 on another workbench 121 equipped with the front subframe assembly 39, which includes four D20 positioning mechanisms 177, four D21 clamping mechanisms 178, two D22 clamping mechanisms 179, two D23 clamping mechanisms 180, two D24 clamping mechanisms 181, and two D25 clamping mechanisms 182.

[0158] Each third hole 42 of the front subframe assembly 39 is provided with a positioning mechanism 177 of number D20, and each positioning mechanism 177 of number D20 is matched with a clamping mechanism 178 of number D21. The clamping mechanism 178 of number D21 is used to clamp the left longitudinal beam assembly 36 and the right longitudinal beam assembly 37 respectively; each clamping mechanism 179 of number D22 corresponds to the first hole 40 and the second hole 40 adjacent on both sides of the rear crossbeam assembly 31. 1. The rear crossbeam assembly 31 is clamped; a D23 clamping mechanism 180 is provided on both sides of the front crossbeam 38 near the third hole 42 to clamp the front crossbeam 38; a D24 clamping mechanism 181 is provided in the middle of the left longitudinal beam assembly 36 and the right longitudinal beam assembly 37 to clamp the corresponding left longitudinal beam assembly 36 and right longitudinal beam assembly 37; each D25 clamping mechanism 182 clamps one stabilizer bar mounting bracket 30. This prevents the left longitudinal beam assembly 36, right longitudinal beam assembly 37, front crossbeam 38 and rear crossbeam assembly 31 from loosening or even falling off during the welding process to form the front subframe assembly 39, which would affect the welding quality of the front subframe assembly 39.

[0159] See attached document Figure 14 The fifth welding workstation 18 in steps S17-19 has two worktables 121 equipped with front subframes 2. Each worktable 121 has a clamping mechanism 122 including four E11 positioning mechanisms 183, four E11 clamping mechanisms 184 and two E12 clamping mechanisms 185.

[0160] Each third hole 42 of the front subframe 2 is provided with an E11 positioning mechanism 183, and each E11 positioning mechanism 183 is matched with an E11 clamping mechanism 184, which is used to clamp the front subframe 2. Each E12 clamping mechanism 185 clamps an energy-absorbing box 28. This prevents the front subframe assembly 39 and the two energy-absorbing boxes 28 from loosening or even falling off during the welding process to form the front subframe 2, which would affect the welding quality of the front subframe 2.

[0161] The first hole 40 of the lower plate of the rear crossbeam 211, the first hole 40 of the rear crossbeam assembly 1 23, and the first hole 40 of the rear crossbeam assembly 2 27 are all the same first hole 40; the second hole 41 of the rear crossbeam assembly 1 23 and the second hole 41 of the rear crossbeam assembly 2 27 are all the same second hole 41; the third hole 42 of the left longitudinal beam assembly 1 32, the third hole 42 of the right longitudinal beam assembly 1 33, the third hole 42 of the left longitudinal beam assembly 36, and the third hole 42 of the right longitudinal beam assembly 37 are all the same third hole 42; the fourth hole 43 of the left longitudinal beam assembly 1 32, the fourth hole 43 of the right longitudinal beam assembly 1 33, the fourth hole 43 of the left longitudinal beam assembly 36, and the fourth hole 43 of the right longitudinal beam assembly 37 are all the same fourth hole 43.

[0162] The above description, in conjunction with specific embodiments, provides a further detailed explanation of the present invention. It should not be construed that the specific implementation of the present invention is limited to these descriptions. For those skilled in the art, several simple deductions or substitutions can be made without departing from the concept of the present invention, and all such deductions or substitutions should be considered to fall within the scope of protection defined by the claims submitted herein.

Claims

1. A method for producing a front subframe of an automobile, applied in a front subframe welding production line, the front subframe welding production line comprising: Five identical welding workstations are arranged and assembled along the axis of the three-axis positioner, namely, the first welding workstation, the second welding workstation, the third welding workstation, the fourth welding workstation, and the fifth welding workstation. Each welding workstation includes a three-axis positioner, a fixture, and two welding robots. The three-axis positioner is mounted on the bottom wall of the welding workstation, and two welding robots are located on one side of the three-axis positioner. The three-axis positioner includes a horizontal central axis and two working axes parallel to the central axis. The side of the three-axis positioner facing the welding robots is the welding side, and the side of the three-axis positioner furthest from the welding robots is the welding side. The other side of the robot is the preparation side. Two working axes are symmetrically arranged on both sides of the central rotating shaft and rotate around the axial direction of the central rotating shaft, so that the working axes can rotate from the preparation side to the welding side, or from the welding side to the preparation side. Both the preparation side and the welding side are rotatably mounted with worktables, which rotate around the corresponding working axis. The fixture includes a worktable and several clamping mechanisms for clamping the workpiece to be welded. The welding robot is equipped with a welding torch for welding the workpiece clamped on the welding side worktable. The method for producing the front subframe of an automobile includes the following steps: S1: Place the lower plate of the rear crossbeam and the reinforcing plate on the workbench on the preparatory side of the first welding workstation, and fix them with several clamping mechanisms; S2: The three-axis positioner of the first welding workstation performs the first rotation of the central axis, so that the worktable equipped with the rear crossbeam lower plate and the reinforcing plate is rotated to the welding side. Two welding robots weld the reinforcing plate and the rear crossbeam lower plate accordingly to obtain the rear crossbeam lower plate assembly. At the same time, another welded rear crossbeam lower plate assembly and rear crossbeam upper plate are placed on another workbench on the preparatory side of the first welding workstation and fixed with several clamping mechanisms; then the left lifting lug and lifting lug reinforcing plate are placed on the other side of another workbench of the first welding workstation and fixed with several clamping mechanisms. S3: After the welding work on the welding side of the first welding workstation is completed and the preparation work on the preparation side of the first welding workstation is completed, the three-axis positioner of the first welding workstation will rotate the central shaft a second time, so that the worktable equipped with the rear crossbeam lower plate assembly will be rotated to the preparation side, and the rear crossbeam lower plate assembly will be unloaded manually. At the same time, another workbench equipped with the rear crossbeam lower plate assembly and the rear crossbeam upper plate is moved to the welding side. Two welding robots weld the rear crossbeam lower plate assembly and the rear crossbeam upper plate accordingly, and weld the left lifting lug and the lifting lug reinforcing plate accordingly, to obtain the rear crossbeam assembly and the left lifting lug assembly respectively. S4: The three-axis positioner of the first welding workstation will rotate the central shaft for the third time, so that the other worktable equipped with the rear crossbeam assembly and the left lifting lug assembly will return to the preparation side, and the rear crossbeam assembly and the left lifting lug assembly will be unloaded manually. S5: First, place the rear crossbeam assembly, left lug assembly, right lug and two steering gear steel sleeves on one side of the workbench on the preparation side of the second welding workstation, and fix them with several clamping mechanisms; Next, place the two sets of energy-absorbing box assemblies, each set including an upper energy-absorbing box plate and a lower energy-absorbing box plate, on the other side of the preparation side workbench, and fix them with several clamping mechanisms. S6: The three-axis positioner of the second welding workstation performs the first rotation of the central shaft, so that the workbench equipped with the rear crossbeam assembly one is rotated to the welding side. The two welding robots weld the rear crossbeam assembly one, the lifting lug assembly, the right lifting lug and the two steering gear steel sleeves accordingly, and weld the upper plate and lower plate of the two sets of energy absorption boxes accordingly, to obtain the rear crossbeam assembly two and the two sets of energy absorption boxes respectively. At the same time, another welded rear crossbeam assembly, rear suspension mounting bracket and stabilizer bar mounting bracket are placed on another workbench on the preparatory side of the second welding workstation and fixed with several clamping mechanisms. S7: After the welding work on the welding side of the second welding workstation is completed and the preparation work on the preparation side of the second welding workstation is completed, the three-axis positioner of the second welding workstation rotates the central shaft for the second time, so that the worktable equipped with the second rear crossbeam assembly and the energy absorption box returns to the preparation side, and the rear crossbeam assembly and the energy absorption box are unloaded manually. At the same time, another workbench equipped with the second rear crossbeam assembly, the rear suspension mounting bracket and the stabilizer bar mounting bracket is moved to the welding side, and two welding robots weld the second rear crossbeam assembly, the rear suspension mounting bracket and the stabilizer bar mounting bracket accordingly to obtain the rear crossbeam assembly; S8: After the welding work on the welding side of the second welding workstation is completed, the three-axis positioner of the second welding workstation will rotate the central shaft for the third time, so that the other worktable equipped with the rear crossbeam assembly returns to the preparation side, and the rear crossbeam assembly is unloaded manually. S9: Place the upper plate and lower plate of the left longitudinal beam on the workbench on the preparation side of the third welding workstation and fix them with several clamping mechanisms; S10: The three-axis positioner of the third welding workstation performs the first rotation of the central axis, so that the worktable equipped with the upper plate and lower plate of the left longitudinal beam moves to the welding side. The two welding robots weld the upper plate and lower plate of the left longitudinal beam accordingly to obtain the left longitudinal beam assembly. At the same time, the upper plate of the right longitudinal beam and the lower plate of the right longitudinal beam are placed on another workbench on the preparation side of the third welding workstation and fixed with several clamping mechanisms. S11: After the welding work on the welding side of the third welding workstation is completed and the preparation work on the preparation side of the third welding workstation is completed, the three-axis positioner of the third welding workstation will rotate the central axis for the second time, so that the worktable equipped with the left longitudinal beam assembly 1 will be rotated to the preparation side, and the left longitudinal beam assembly 1 will be unloaded manually. At the same time, another workbench equipped with the upper plate and lower plate of the right longitudinal beam is moved to the welding side, and two welding robots weld the upper plate and lower plate of the right longitudinal beam to obtain the right longitudinal beam assembly. S12: After the welding work on the welding side of the third welding workstation is completed, the three-axis positioner of the third welding workstation will rotate the central shaft for the third time, so that the other worktable equipped with the right longitudinal beam assembly will return to the preparation side, and the right longitudinal beam assembly will be unloaded manually. S13: First, place the left longitudinal beam assembly, the two composite bushings, and the two swing arm front mounting steel sleeves on one side of the workbench on the preparation side of the fourth welding workstation, and fix them with several clamping mechanisms. Then place the right longitudinal beam assembly, the two composite bushings, and the two swing arm front mounting steel sleeves on the other side of the preparatory workbench of the fourth welding workstation, and fix them with several clamping mechanisms. S14: The three-axis positioner of the fourth welding workstation performs the first rotation of the central axis, so that the worktable equipped with the left longitudinal beam assembly and the right longitudinal beam assembly are rotated to the welding side. The two welding robots weld the left longitudinal beam assembly, the two composite bushings and the two front mounting steel sleeves of the swing arms accordingly, and weld the right longitudinal beam assembly, the two composite bushings and the two front mounting steel sleeves of the swing arms accordingly, to obtain the left longitudinal beam assembly and the right longitudinal beam assembly respectively. At the same time, another welded left longitudinal beam assembly, another welded right longitudinal beam assembly, front crossbeam and rear crossbeam assembly are placed on another workbench of the fourth welding workstation and fixed with several clamping mechanisms. S15: After the welding work on the welding side of the fourth welding workstation is completed and the preparation work on the preparation side of the fourth welding workstation is completed, the three-axis positioner of the fourth welding workstation will rotate the central shaft a second time to return the worktable containing the left longitudinal beam assembly and the right longitudinal beam assembly to the preparation side, and the left longitudinal beam assembly and the right longitudinal beam assembly will be unloaded manually. At the same time, another workbench equipped with the left longitudinal beam assembly, right longitudinal beam assembly, front crossbeam and rear crossbeam assembly is moved to the welding side, and two welding robots weld the left longitudinal beam assembly, right longitudinal beam assembly, front crossbeam and rear crossbeam assembly accordingly to obtain the first front subframe assembly. S16: After the welding work on the welding side of the fourth welding workstation is completed, the three-axis positioner of the fourth welding workstation will rotate the central shaft for the third time, so that the other workbench equipped with the front subframe assembly 1 returns to the preparation side, and the front subframe assembly 1 is unloaded manually. S17: Place the front subframe assembly and the two energy-absorbing boxes on the preparatory side of the fifth welding station and fix them with several clamping mechanisms. S18: The three-axis positioner of the fifth welding workstation performs the first rotation of the central shaft, so that the worktable equipped with the first front subframe assembly and the energy absorption box is rotated to the welding side. Two welding robots weld the first front subframe assembly and the two energy absorption boxes accordingly to obtain the finished product - the front subframe. S19: At the same time, repeat steps S17 and S18 on another workbench located on the preparation side of the fifth welding workstation.

2. The method for producing a front subframe of an automobile according to claim 1, characterized in that, The front subframe described in step S18, wherein the front crossbeam, the left longitudinal beam assembly, the right longitudinal beam assembly, and the rear crossbeam assembly are sequentially welded to form a closed isosceles trapezoid, and the length of the front crossbeam is greater than the length of the rear crossbeam assembly. The left longitudinal beam assembly and the right longitudinal beam assembly both extend from the rear crossbeam assembly, and a stabilizer bar mounting bracket is welded between the extended portion and the rear crossbeam assembly. A rear suspension mounting bracket is welded to the lower side wall of the rear crossbeam assembly. The rear suspension mounting bracket is close to the left longitudinal beam assembly. A right hanger rod is welded between the rear suspension mounting bracket and the rear crossbeam assembly. A left hanger rod assembly is welded to the side of the right hanger rod facing the right longitudinal beam assembly. The lower sidewall of the rear crossbeam assembly has a first hole at each end of one side. The first hole penetrates the rear crossbeam assembly and a steering gear steel sleeve is welded inside. This side is away from the stabilizer bar mounting bracket. Each first hole has a corresponding second hole on the side facing the stabilizer bar mounting bracket. The second hole penetrates the rear crossbeam assembly. Both ends of the left longitudinal beam assembly and the right longitudinal beam assembly are provided with a third hole, which penetrates the left longitudinal beam assembly and has a composite bushing welded inside. The middle of the left longitudinal beam assembly and the middle of the right longitudinal beam assembly are provided with two fourth holes, which penetrate the left longitudinal beam assembly and have a swing arm front mounting steel sleeve welded inside. Both the left longitudinal beam assembly and the right longitudinal beam assembly are provided with a swing arm mounting groove on the side facing the rear cross beam assembly, and the swing arm mounting groove is adjacent to the stabilizer bar mounting bracket. An energy-absorbing box is welded to one side wall of both the left and right longitudinal beam assemblies facing the front crossbeam.

3. The method for producing a front subframe of an automobile according to claim 2, characterized in that, The first welding workstation in steps S1-S4 has a clamping mechanism on its worktable equipped with the rear crossbeam lower plate assembly, which includes two A10 positioning mechanisms, two A11 clamping mechanisms, one A12 clamping mechanism, and one A10 auxiliary support mechanism. The clamping mechanism on another workbench, which is equipped with the rear crossbeam assembly and the left lifting lug assembly, includes two A20 positioning mechanisms, two A21 clamping mechanisms, one A22 clamping mechanism, one A23 clamping mechanism, and four A20 side-top mechanisms. Each first hole in the lower plate of the rear crossbeam is provided with a positioning mechanism A10; a clamping mechanism A11 is provided on the opposite side of each of the two positioning mechanisms A10, which is used to clamp the lower plate of the rear crossbeam; the clamping mechanism A12 is used to clamp the reinforcing plate to the lower plate of the rear crossbeam; the outer bottom wall of the lower plate of the rear crossbeam is provided with an auxiliary support mechanism A10 corresponding to the position of the reinforcing plate. Each first hole of the rear crossbeam assembly is provided with a positioning mechanism of type A20; each clamping mechanism of type A21 is provided with a second hole of the rear crossbeam assembly, and then clamps the rear crossbeam assembly; the clamping mechanism of type A22 is used to clamp the middle part of the rear crossbeam assembly; each end of the two side walls of the rear crossbeam assembly is provided with a side top mechanism of type A20; the clamping mechanism of type A23 is used to clamp the left lifting lug and the lifting lug reinforcing plate accordingly.

4. The method for producing a front subframe of an automobile according to claim 2, characterized in that, The second welding workstation in steps S5-S8 has a clamping mechanism on its worktable equipped with the rear crossbeam assembly and the energy absorption box, which includes two B10 positioning mechanisms, two B11 clamping mechanisms, two B12 clamping mechanisms, one B13 clamping mechanism, one B14 clamping mechanism and two B15 clamping mechanisms. The clamping mechanism on another workbench equipped with the rear crossbeam assembly includes two B20 positioning mechanisms, two B21 clamping mechanisms, two B22 clamping mechanisms, and one B23 clamping mechanism. Each first hole of the second rear crossbeam assembly is provided with a B10 positioning mechanism; each B11 clamping mechanism is used to clamp a steering gear steel sleeve to the first hole of the second rear crossbeam assembly; the B12 clamping mechanism is respectively provided with a second hole of the second rear crossbeam assembly and then clamps the second rear crossbeam assembly. The B13 clamping mechanism is used to clamp the right lifting lug and the rear crossbeam assembly in a corresponding manner; the B14 clamping mechanism is used to clamp the left lifting lug assembly and the rear crossbeam assembly in a corresponding manner; each of the B15 clamping mechanisms is used to clamp the upper plate and the lower plate of the energy absorption box in a corresponding manner. Each first hole of the rear crossbeam assembly is provided with a B20 positioning mechanism; each B21 clamping mechanism is provided with a second hole of the rear crossbeam assembly, and then the rear crossbeam assembly is clamped. The B22 clamping mechanism is used to clamp one of the stabilizer bar mounting brackets; each of the B23 clamping mechanisms is used to clamp the rear suspension mounting bracket to the rear crossbeam assembly.

5. The method for producing a front subframe of an automobile according to claim 2, characterized in that, The third welding workstation in steps S9-S12 has a clamping mechanism on its workbench equipped with the left longitudinal beam assembly, which includes two C10 positioning mechanisms, one C11 clamping mechanism, two C10 pressing mechanisms, and four C10 side-top mechanisms. The clamping mechanism on another workbench equipped with the right longitudinal beam assembly includes two C20 positioning mechanisms, one C21 clamping mechanism, two C20 pressing mechanisms, and four C20 side-top mechanisms. Each of the C10 clamping mechanisms clamps one of the composite bushings to the corresponding third hole of the left longitudinal beam assembly; each of the C11 clamping mechanisms clamps the middle part of the left longitudinal beam assembly; a first positioning hole is provided between each third hole and the corresponding fourth hole, the first positioning hole penetrating the left longitudinal beam assembly, and a corresponding C10 positioning mechanism is provided in each first positioning hole; a C10 side-top mechanism is provided at both ends of the two side walls of the middle part of the left longitudinal beam assembly; Each of the C20 clamping mechanisms clamps one of the composite bushings to the corresponding third hole of the right longitudinal beam assembly; the C21 clamping mechanism is used to clamp the middle part of the right longitudinal beam assembly; a second positioning hole is provided between each third hole and the corresponding fourth hole, the second positioning hole penetrates the right longitudinal beam assembly, and a C20 positioning mechanism is provided in each second positioning hole; a C20 side-top mechanism is provided at both ends of the two side walls of the middle part of the right longitudinal beam assembly.

6. The method for producing a front subframe of an automobile according to claim 2, characterized in that, The fourth welding workstation in steps S13-16 has a clamping mechanism on its worktable equipped with the left and right longitudinal beam assemblies, comprising four D11 positioning mechanisms, two D11 auxiliary support mechanisms, two D11 clamping mechanisms, two D12 clamping mechanisms, four D13 clamping mechanisms, and two D14 clamping mechanisms; the D11 clamping mechanism includes a D111 clamping part and a D112 clamping part. Each third hole of the left longitudinal beam assembly is provided with a positioning mechanism D11. The clamping part D111 corresponds to the third hole adjacent to the swing arm mounting slot and clamps the left longitudinal beam assembly. A support mechanism D11 extends into the swing arm mounting slot. The clamping part D112 corresponds to the support mechanism D11 and clamps one wall of the swing arm mounting slot. The clamping mechanism D12 corresponds to another third hole away from the swing arm mounting slot and clamps the left longitudinal beam assembly. Two clamping mechanisms D13 are used to clamp the steering gear sleeve to the corresponding fourth hole. A clamping mechanism D14 is provided between the clamping mechanisms D12 and D13, and this clamping mechanism D14 is used to clamp the left longitudinal beam assembly. Each third hole of the right longitudinal beam assembly is provided with a positioning mechanism D11. The clamping part D111 corresponds to the third hole adjacent to the swing arm mounting slot and clamps the right longitudinal beam assembly. A support mechanism D11 extends into the swing arm mounting slot. The clamping part D112 corresponds to the support mechanism D11 and clamps one wall of the swing arm mounting slot. The clamping mechanism D12 corresponds to another third hole away from the swing arm mounting slot and clamps the right longitudinal beam assembly. Two clamping mechanisms D13 are used to clamp the steering gear sleeve to the corresponding fourth hole. A clamping mechanism D14 is provided between the clamping mechanisms D12 and D13, and the clamping mechanism D14 is used to clamp the right longitudinal beam assembly.

7. The method for producing a front subframe of an automobile according to claim 2, characterized in that, The fourth welding workstation in steps S13-16 has a clamping mechanism on another workbench equipped with the front subframe assembly, which includes four D20 positioning mechanisms, four D21 clamping mechanisms, two D22 clamping mechanisms, two D23 clamping mechanisms, two D24 clamping mechanisms, and two D25 clamping mechanisms. Each third hole of the front subframe assembly is provided with a positioning mechanism of type D20, and each positioning mechanism of type D20 is matched with a clamping mechanism of type D21. The clamping mechanism of type D21 is used to clamp the left longitudinal beam assembly and the right longitudinal beam assembly respectively. Each clamping mechanism of type D22 corresponds to the first hole and the second hole on both sides of the rear crossbeam assembly and clamps the rear crossbeam assembly. Each side of the front crossbeam near the third hole is provided with a clamping mechanism of type D23 to clamp the front crossbeam. The middle part of the left longitudinal beam assembly and the right longitudinal beam assembly are respectively provided with a clamping mechanism of type D24 to clamp the corresponding left longitudinal beam assembly and the right longitudinal beam assembly. Each clamping mechanism of type D25 clamps a stabilizer bar mounting bracket.

8. The method for producing a front subframe of an automobile according to claim 2, characterized in that, The fifth welding workstation in steps S17-19 has two workstations equipped with a front subframe. The clamping mechanism of the two workstations includes four E11 positioning mechanisms, four E11 clamping mechanisms, and two E12 clamping mechanisms. Each E11 clamping mechanism includes an E111 positioning part and an E111 clamping part. Each third hole of the front subframe is provided with an E11 positioning mechanism, and each E11 positioning mechanism is matched with an E11 clamping mechanism, which is used to clamp the front subframe; each E12 clamping mechanism clamps an energy-absorbing box.

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