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

Abstract

The application relates to an automobile rear subframe welding production line and an automobile front subframe production method. The automobile rear subframe welding production line comprises multiple welding workstations, the welding workstations comprise a three-axis positioner, a clamp tool and two welding robots, the three-axis positioner is installed on the bottom wall of the welding workstation, two welding robots are arranged on one side of the three-axis positioner, clamp tools are rotatably installed on the two sides of the three-axis positioner, and welding guns are arranged on the welding robots and used for welding workpieces clamped on the welding side workbench. The automobile rear subframe production method is applied to the automobile rear subframe welding production line, can reasonably distribute the welding workload of each sequence, reduces the welding time of one rear subframe, and improves the 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 automotive rear subframes and a manufacturer of automotive rear subframes. Background Technology

[0002] Current traditional automotive rear subframe welding production lines divide the welding process between the various parts of the rear subframe into five stages. The loading and welding cycles of each stage are not independent and can affect each other, thus reducing welding efficiency. Moreover, the workload of each stage is not reasonably allocated, resulting in long welding times and low welding efficiency for welding a single automotive rear subframe. Summary of the Invention

[0003] In view of this, the present invention provides a welding production line for automotive rear subframes, which allows the loading cycle and welding cycle of each welding workstation to be independent and not interfere with each other. The present invention also provides a method for producing automotive rear subframes, which can reasonably allocate the welding workload of each sequence, reduce the welding time of welding a rear subframe, and improve welding efficiency.

[0004] To achieve one or more of the above objectives or other objectives, the present invention proposes a welding production line for automotive rear subframes, comprising multiple welding workstations, wherein each welding workstation includes a three-axis positioner, a fixture, and two welding robots.

[0005] 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;

[0006] 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.

[0007] The fixture includes a worktable and several clamping mechanisms, which are used to clamp the workpiece to be welded. The clamping mechanisms can be detachably mounted on the worktable or fixedly mounted on the worktable. Both the preparation side and the welding side are rotatably mounted on worktables, which rotate around their respective working axes. The welding robot is equipped with a welding torch, which is used to weld the workpiece clamped on the welding side worktable.

[0008] Furthermore, there are four 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 and the fourth welding workstation.

[0009] A method for producing a rear subframe of an automobile, applied to the aforementioned automobile rear subframe welding production line, includes the following steps:

[0010] S1: Place the front plate and rear plate of the middle crossbeam on one side of the workbench of the first welding workstation, and place the welded middle crossbeam assembly and the lower arm mounting bushing on the other side of the workbench. Then fix them with several clamping mechanisms. Then rotate the workbench to the welding side and two welding robots weld to obtain the middle crossbeam assembly and the middle crossbeam assembly.

[0011] S2: The rear crossbeam, two rear subframe mounting bushings, exhaust pipe hangers, and two stabilizer bar mounting brackets are placed in the middle of another workbench on the preparatory side of the first welding workstation. A front suspension mounting bracket rear plate assembly and a front suspension mounting bracket reinforcing plate are placed on both sides of this other workbench, and then fixed with several clamping mechanisms. Then the other workbench is rotated to the welding side, and two welding robots perform welding to obtain the rear crossbeam assembly and the two front suspension mounting bracket rear plates.

[0012] S3: Place the rear crossbeam assembly and the rear suspension mounting bracket in the middle of the workbench on the preparation side of the second welding workstation. Place a front plate of the control arm mounting bracket and a rear plate of the control arm mounting bracket on each side of the workbench, and then fix them with several clamping mechanisms. Then rotate the workbench to the welding side, and two welding robots perform welding to obtain the rear crossbeam assembly and two control arm mounting brackets.

[0013] S4: The front crossbeam and the two rear subframe mounting bushings are placed in the middle of another workbench on the preparatory side of the second welding workstation. On the two sides of this other workbench, an upper arm mounting bracket assembly and an upper arm mounting bracket reinforcing plate are placed respectively, and then fixed with several clamping mechanisms. Then the other workbench is rotated to the welding side, and two welding robots perform welding to obtain the front crossbeam assembly and the two upper arm mounting brackets.

[0014] S5: Place the middle crossbeam assembly, rear crossbeam assembly, front crossbeam assembly, left longitudinal beam and right longitudinal beam on the workbench on the preparation side of the third welding workstation, and then fix them with several clamping mechanisms; then the workbench is rotated to the welding side, and two welding robots perform welding to obtain the rear subframe assembly.

[0015] S6: Place the rear subframe assembly one, the two control arm mounting brackets and the two upper arm mounting brackets on another workbench on the preparation side of the third welding workstation, and then fix them with several clamping mechanisms; then rotate the other workbench to the welding side, and the two welding robots perform welding to obtain the rear subframe assembly two.

[0016] S7: Place the rear subframe assembly II, the front plates of the two front suspension mounting brackets, the front plates of the two guide arm mounting brackets, and the rear plates of the two guide arm mounting brackets on the workbench on the preparation side of the fourth welding workstation, and then fix them with several clamping mechanisms; then rotate the workbench to the welding side, and two welding robots perform welding to obtain the rear subframe assembly III;

[0017] S8: The rear subframe assembly, the two front suspension mounting bracket rear plates, and the two tow arm mounting brackets are placed on another workbench on the preparatory side of the fourth welding workstation, and then fixed with several clamping mechanisms; then the workbench is rotated to the welding side, and two welding robots perform welding to obtain the finished product - the automobile rear subframe.

[0018] Furthermore, when the workbench on the preparation side is rotated to the welding side for welding in steps S1-S8, at the same time, another workbench on the preparation side is manually loaded, or the workpiece welded on the other workbench is unloaded first and then reloaded.

[0019] Furthermore, after the workpieces in steps S1-S8 are welded, the three-axis positioner of the corresponding welding workstation flips the central axis, rotates the worktable located on the welding side to the preparation side, manually unloads the welded workpiece, and then transfers the unloaded workpiece to the welding workstation of the other corresponding steps.

[0020] Furthermore, the rear subframe of the vehicle described in step S8 is formed by welding the front crossbeam assembly, the right longitudinal beam, the rear crossbeam assembly, and the left longitudinal beam in sequence to form a closed trapezoid, and the length of the front crossbeam assembly is greater than the length of the rear crossbeam assembly;

[0021] The middle part of the rear crossbeam assembly is welded to one end of the rear suspension mounting bracket, the other end of the rear suspension mounting bracket is welded to the middle part of the middle crossbeam assembly, one end of the middle crossbeam assembly is welded to the side of the left longitudinal beam near the rear crossbeam assembly, and the other end of the middle crossbeam assembly is welded to the side of the right longitudinal beam near the rear crossbeam assembly.

[0022] A rear subframe mounting bushing is welded to each end of the front crossbeam assembly and the rear crossbeam assembly; a stabilizer bar mounting bracket is welded to each side of the rear crossbeam assembly near the rear subframe mounting bushing, and each stabilizer bar mounting bracket is adjacent to the corresponding rear subframe mounting bushing. A first through hole penetrating the rear crossbeam assembly is opened below each stabilizer bar mounting bracket; an exhaust pipe hanger is welded to the side of the rear crossbeam assembly near the left longitudinal beam assembly, and the exhaust pipe hanger extends toward the middle crossbeam.

[0023] Each of the left and right longitudinal beams has a control arm mounting bracket on its opposite side, and each control arm mounting bracket is close to the front crossbeam assembly; each control arm mounting bracket has an upper arm mounting bracket on its side away from the front crossbeam assembly.

[0024] The left and right longitudinal beams are each provided with a guide arm mounting bracket front plate on the back side near the front crossbeam assembly, and each guide arm mounting bracket front plate is provided with a guide arm mounting bracket rear plate on the side away from the front crossbeam assembly.

[0025] A front suspension mounting bracket front plate is provided between the opposite side of the left and right longitudinal beams and the front crossbeam assembly, and a front suspension mounting bracket rear plate is provided on the side of the front suspension mounting bracket away from the front crossbeam assembly.

[0026] A traction arm mounting bracket is provided on the front of the connection between the left longitudinal beam and the right longitudinal beam and the front cross beam assembly.

[0027] A second through hole is provided on each side of the connection between the middle crossbeam assembly and the rear suspension mounting bracket. The second through hole is used to install the lower arm mounting bushing. A third through hole is provided on each side of the middle crossbeam assembly near the left and right longitudinal beams.

[0028] Furthermore, the first welding workstation in steps S1-S2 has a clamping mechanism on its workbench equipped with a central crossbeam assembly, which includes one A11 clamping mechanism, two A12 clamping mechanisms, one A13 clamping mechanism, two A14 clamping mechanisms, two A11 positioning mechanisms, two A12 positioning mechanisms, and one A11 side-top mechanism.

[0029] The clamping mechanism on another workbench equipped with the rear crossbeam assembly includes two A21 positioning mechanisms, two A22 positioning mechanisms, two A21 clamping mechanisms, one A22 clamping mechanism, two A23 clamping mechanisms, two A24 clamping mechanisms, and two A25 clamping mechanisms.

[0030] Each of the third through holes of the middle crossbeam assembly is provided with a positioning mechanism A11; the clamping mechanism A11 is used to clamp the middle part of the middle crossbeam assembly, and each clamping mechanism A12 is used to clamp one side of the middle crossbeam assembly; each of the two side walls of the middle crossbeam assembly is provided with a side support mechanism A11 to support the middle crossbeam assembly.

[0031] Each second through hole of the middle crossbeam assembly is provided with a positioning mechanism A12; each clamping mechanism A14 is provided with two clamping parts, which correspond to the adjacent positioning mechanisms A11 and A12 respectively, to clamp the middle crossbeam assembly; the clamping mechanism A13 is used to clamp the middle part of the middle crossbeam assembly.

[0032] Each of the rear subframe mounting bushings is fitted onto the corresponding positioning mechanism A21, which clamps the rear subframe mounting bushing. Each first through hole of the rear crossbeam assembly is provided with a positioning mechanism A22. The clamping mechanism A22 clamps the exhaust pipe lug. The clamping mechanism A23 clamps the stabilizer bar mounting bracket. Each clamping mechanism A24 clamps a front suspension mounting bracket rear plate assembly. Each clamping mechanism A25 clamps a front suspension mounting bracket reinforcement plate.

[0033] Furthermore, the second welding workstation in steps S3-S4 has a clamping mechanism on its workbench equipped with the rear crossbeam assembly, which includes two B11 positioning clamping mechanisms, two B11 clamping mechanisms, one B12 clamping mechanism, one B13 clamping mechanism, and two B14 clamping mechanisms.

[0034] The clamping mechanism on another workbench equipped with the front crossbeam assembly includes two B21 positioning clamping mechanisms, two B21 clamping mechanisms, two B22 clamping mechanisms, and two B23 clamping mechanisms.

[0035] Each of the B11 positioning and clamping mechanisms first positions the rear subframe mounting bushing of the rear crossbeam assembly, and then clamps the rear subframe mounting bushing; each of the B11 clamping mechanisms is used to clamp a stabilizer bar mounting bracket; the B12 clamping mechanism clamps the rear suspension mounting bracket from both sides, and the B13 clamping mechanism clamps the rear suspension mounting bracket from the top; each of the B14 clamping mechanisms clamps a control arm mounting bracket.

[0036] Each of the B21 positioning and clamping mechanisms first positions the rear subframe mounting bushing of the front crossbeam assembly, and then clamps the rear subframe mounting bushing; each of the B21 clamping mechanisms is located close to the corresponding B21 positioning and clamping mechanism, and then clamps the front crossbeam assembly; each of the B21 clamping mechanisms has a B22 clamping mechanism on the side away from the B21 positioning and clamping mechanism, which is used to clamp the front crossbeam assembly; each of the B23 clamping mechanisms is used to clamp an upper arm mounting bracket.

[0037] Furthermore, the clamping mechanism on the workbench of the third welding workstation in steps S5-S6, which is equipped with the rear subframe assembly, includes four C11 positioning clamping mechanisms, two C12 positioning clamping mechanisms, two C13 positioning clamping mechanisms, one C11 clamping mechanism, one C12 clamping mechanism, and two C13 clamping mechanisms.

[0038] The clamping mechanism on another workbench equipped with the second rear subframe assembly includes four C21 positioning clamping mechanisms, two C21 clamping mechanisms, two C22 clamping mechanisms, and two C23 clamping mechanisms.

[0039] Each of the C11 positioning and clamping mechanisms first positions the subframe mounting bushing of the rear subframe assembly, and then clamps the rear subframe mounting bushing; each of the left and right longitudinal beams is provided with a C12 positioning and clamping mechanism at one end near the rear crossbeam assembly to clamp the corresponding left and right longitudinal beams; each of the left and right longitudinal beams is provided with a C13 positioning and clamping mechanism at one end near the front crossbeam assembly to clamp the corresponding left and right longitudinal beams; the C11 clamping mechanism is used to clamp the middle part of the front crossbeam assembly; the C12 clamping mechanism is used to clamp the rear suspension mounting bracket; each of the C13 clamping mechanisms is used to clamp one end of the middle crossbeam assembly;

[0040] Each of the C21 positioning and clamping mechanisms first positions the subframe mounting bushing of the second rear subframe assembly, and then clamps the rear subframe mounting bushing; each of the C21 clamping mechanisms is used to clamp a control arm mounting bracket; each of the C22 clamping mechanisms is used to clamp an upper arm mounting bracket; each of the left and right longitudinal beams is provided with a C23 positioning and clamping mechanism at one end near the front crossbeam assembly to clamp the corresponding left and right longitudinal beams.

[0041] Furthermore, in the fourth welding workstation of steps S7-S8, the clamping mechanism on the workbench equipped with the rear subframe assembly three includes four D11 positioning clamping mechanisms, two D12 positioning clamping mechanisms, two D13 positioning clamping mechanisms, and two D11 clamping mechanisms.

[0042] The clamping mechanism on the workbench equipped with the rear subframe of the vehicle includes four D21 positioning clamping mechanisms, two D21 clamping mechanisms, and two D22 clamping mechanisms.

[0043] Each of the D11 positioning and clamping mechanisms first positions the rear subframe mounting bushing of the rear subframe assembly three, and then clamps the rear subframe mounting bushing; each of the D12 positioning and clamping mechanisms includes two positioning and clamping parts, one of which positions and clamps a guide arm mounting bracket front plate; the other positioning and clamping part positions and clamps a guide arm mounting bracket rear plate; each of the D13 positioning and clamping mechanisms first positions one end near the center crossbeam assembly, and then clamps that end near the center crossbeam assembly; each of the D11 clamping mechanisms is used to clamp a front suspension mounting bracket front plate;

[0044] Each of the D21 positioning and clamping mechanisms first positions the rear subframe mounting bushing of the vehicle's rear subframe, and then clamps the rear subframe mounting bushing; each of the D21 clamping mechanisms is used to clamp a front suspension mounting bracket rear plate; each of the D22 clamping mechanisms is used to clamp a tow arm mounting bracket.

[0045] Implementing the embodiments of the present invention will have the following beneficial effects:

[0046] This invention proposes a welding production line for automotive rear subframes, in which the three-axis positioners of the welding workstations can rotate the fixtures from the preparation side to the welding side, or from the welding side to the preparation side, making the loading cycle and welding cycle of each welding workstation independent and unaffected, thereby improving welding efficiency. This invention also proposes a method for producing automotive rear subframes, dividing the welding steps between the various parts of the front subframe into eight sequences, rationally allocating the welding workload of each sequence, reducing the welding time for welding a single automotive rear subframe, and improving welding efficiency. Attached Figure Description

[0047] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0048] in:

[0049] Figure 1 This is a top view of the welding workstation in this application;

[0050] Figure 2 This is a top view of the automotive rear subframe welding production line described in this application;

[0051] Figure 3 This is a schematic diagram of the welding process for step S1 in this application;

[0052] Figure 4 This is a schematic diagram of the welding process for steps S2-S3 in this application;

[0053] Figure 5 This is a schematic diagram of the welding process for step S4 in this application;

[0054] Figure 6 This is a schematic diagram of the welding process for steps S5-S8 in this application;

[0055] Figure 7 This is a structural schematic diagram of the rear subframe of the automobile in this application;

[0056] Figure 8 This is a schematic diagram of the workbench in this application, which is equipped with the middle crossbeam assembly and the middle crossbeam assembly.

[0057] Figure 9 This is a structural schematic diagram of the worktable in this application, which is equipped with the rear crossbeam assembly and the rear plate of the front suspension mounting bracket.

[0058] Figure 10 A schematic diagram of the workbench in this application, which is equipped with a rear crossbeam assembly and a control arm mounting bracket.

[0059] Figure 11 This is a schematic diagram of the workbench in this application, which is equipped with the front crossbeam assembly and the upper arm mounting bracket.

[0060] Figure 12 This is a schematic diagram of the workbench equipped with the rear subframe assembly in this application.

[0061] Figure 13 This is a schematic diagram of the workbench equipped with the second rear subframe assembly in this application.

[0062] Figure 14 This is a schematic diagram of the workbench equipped with the rear subframe assembly three in this application;

[0063] Figure 15 This is a schematic diagram of the workbench equipped with the rear subframe assembly in this application.

[0064] Figure label:

[0065] 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. Control panel; 19. Welding control box;

[0066] 2. Rear subframe of automobile; 21. Center crossbeam assembly; 211. Center crossbeam assembly one; 212. Center crossbeam front plate; 213. Center crossbeam rear plate; 214. Lower arm mounting bushing; 22. Rear crossbeam assembly; 221. Rear crossbeam assembly one; 222. Rear crossbeam; 223. Exhaust pipe hanger; 224. Stabilizer bar mounting bracket; 225. Rear suspension mounting bracket; 23. Front crossbeam assembly; 231. Front crossbeam; 24. Left longitudinal beam; 25. Right longitudinal beam; 26. Rear subframe mounting bushing; 27. Front suspension mounting bracket rear plate; 271. Front suspension mounting bracket rear plate assembly; 27 2. Front suspension mounting bracket reinforcement plate; 28. Control arm mounting bracket; 281. Control arm mounting bracket front plate; 282. Control arm mounting bracket rear plate; 29. ​​Upper arm mounting bracket; 291. Upper arm mounting bracket assembly; 292. Upper arm mounting bracket reinforcement plate; 30. Rear subframe assembly one; 31. Rear subframe assembly two; 32. Rear subframe assembly three; 33. Front suspension mounting bracket front plate; 34. Guide arm mounting bracket front plate; 35. Guide arm mounting bracket rear plate; 36. Traction arm mounting bracket; 37. First through hole; 38. Second through hole; 39. Third through hole;

[0067] 141. Clamping mechanism A11; 142. Clamping mechanism A12; 143. Clamping mechanism A13; 144. Clamping mechanism A14; 145. Positioning mechanism A11; 146. Positioning mechanism A12; 147. Side-mounting mechanism A11; 148. Positioning mechanism A21; 149. Positioning mechanism A22; 150. Clamping mechanism A21; 151. Clamping mechanism A22; 152. Clamping mechanism A23; 153. Clamping mechanism A24; 154. Clamping mechanism A25;

[0068] 155. Positioning and clamping mechanism B11; 156. Clamping mechanism B11; 157. Clamping mechanism B12; 158. Clamping mechanism B13; 159. Clamping mechanism B14; 160. Positioning and clamping mechanism B21; 161. Clamping mechanism B21; 162. Clamping mechanism B22; 163. Clamping mechanism B23;

[0069] 164. Positioning and clamping mechanism C11; 165. Positioning and clamping mechanism C12; 166. Positioning and clamping mechanism C13; 167. Clamping mechanism C11; 168. Clamping mechanism C12; 169. Clamping mechanism C13; 170. Positioning and clamping mechanism C21; 171. Clamping mechanism C21; 172. Clamping mechanism C22; 173. Clamping mechanism C23;

[0070] 174. Positioning and clamping mechanism D11; 175. Positioning and clamping mechanism D12; 176. Positioning and clamping mechanism D13; 177. Clamping mechanism D11; 178. Positioning and clamping mechanism D21; 179. Clamping mechanism D21; 180. Clamping mechanism D22. Detailed Implementation

[0071] 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 in the specification is for the purpose of describing particular embodiments only and is not intended to limit the invention; the terms "comprising" and "having," and any variations thereof, in the specification, claims, and foregoing drawings are intended to cover non-exclusive inclusion. The terms "first," "second," etc., in the specification, claims, or foregoing drawings are used to distinguish different objects and not to describe a particular order.

[0072] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of the invention. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0073] To enable those skilled in the art to better understand the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings.

[0074] As one embodiment, refer to the appendix Figure 1-2 A welding production line for a rear subframe of an automobile includes multiple welding workstations 1, each welding workstation 1 including a three-axis positioner 11, a fixture 12, and two welding robots 13.

[0075] 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.

[0076] 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.

[0077] 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; wherein 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.

[0078] Several clamping mechanisms 122 are detachably mounted on the workbench 121, or several clamping mechanisms 122 are fixedly mounted on the workbench 121; both the preparation side and the welding side are rotatably mounted with workbench 121, and the workbench 121 is rotated around the corresponding working shaft 112.

[0079] The welding robot 13 is equipped with a welding torch, which is used to weld the workpiece held in the welding side worktable 121. The welding robot 13 adopts an existing multi-axis motion robotic arm, and the working end of the robotic arm is the welding torch. The welding torch can be moved to the welding side worktable 121 of the three-axis positioner 11 to perform operations.

[0080] In this embodiment, each welding workstation 1 is provided with a control panel 18 on an outer side wall away from the welding robot 13. The control panel 18 is used to control the start and stop of the welding workstation 1. The control panel 18 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.

[0081] Each welding workstation 1 has a welding control box 19 on its outer side wall away from the control panel 18. The welding control box 19 is used to control the welding action, welding path, welding sequence, etc. of the welding robot 13. The control panel 18 is electrically connected to the welding control box 20, so the control panel 18 can also control the welding robot 13 to weld the workpiece.

[0082] 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 18 is operated. At this time, the clamping mechanism 122 first clamps the corresponding workpiece to be welded. Then, the three-axis positioner 11 rotates to move the original preparatory worktable 121 to the welding side. The welding robot 13 then welds the workpiece to be welded. During the welding process, the worktable 121 with the workpiece to be welded will also rotate to better expose the weld seam of the workpiece to be welded for the welding robot 13 to weld. After the welding is completed, the three-axis positioner 11 rotates again to make the worktable 121 with the workpiece to be welded return to the preparatory side. Then, the welded workpiece is unloaded manually and a new workpiece to be welded is placed on it.

[0083] See attached document Figure 2There are four welding workstations 1, which are arranged and assembled along the axial direction of the three-axis positioner 11, namely, the first welding workstation 14, the second welding workstation 15, the third welding workstation 16, and the fourth welding workstation 17. This arrangement of the welding workstations 1 can reduce the worker's walking time and the workpiece transfer time, and improve the worker's work efficiency and the welding efficiency of the welding workstations 1.

[0084] The present invention also provides a method for producing a rear subframe 2 of an automobile using the aforementioned automobile rear subframe welding production line. As one embodiment, refer to the appendix. Figure 3-15 A method for producing a rear subframe of an automobile, applied to the aforementioned automobile rear subframe welding production line, includes the following steps:

[0085] S1: Place the front plate 212 and the rear plate 213 of the middle crossbeam on one side of the workbench 121 on the preparatory side of the first welding workstation 14. Place the welded middle crossbeam assembly 211 and the lower arm mounting bushing 214 on the other side of the workbench 121 and fix them with several clamping mechanisms 122. Then, rotate the workbench 121 to the welding side and two welding robots 13 perform welding to obtain the middle crossbeam assembly 211 and the middle crossbeam assembly 21.

[0086] S2: The rear crossbeam 222, two rear subframe mounting bushings 26, exhaust pipe hanger 223, and two stabilizer bar mounting brackets 224 are placed in the middle of another workbench 121 on the preparatory side of the first welding workstation 14. A front suspension mounting bracket rear plate assembly 271 and a front suspension mounting bracket reinforcing plate 272 are placed on both sides of the other workbench 121 respectively, and then fixed with several clamping mechanisms 122. Then the other workbench 121 is rotated to the welding side, and two welding robots 13 perform welding to obtain the rear crossbeam assembly 221 and the two front suspension mounting bracket rear plates 27.

[0087] S3: The rear crossbeam assembly 221 and the rear suspension mounting bracket 225 are placed in the middle of the workbench 121 on the preparation side of the second welding workstation 15. A control arm mounting bracket front plate 281 and a control arm mounting bracket rear plate 282 are placed on both sides of the workbench 121 respectively, and then fixed with several clamping mechanisms 122. Then the workbench 121 is rotated to the welding side, and two welding robots 13 perform welding to obtain the rear crossbeam assembly 22 and two control arm mounting brackets 28.

[0088] S4: The front crossbeam 231 and the two rear subframe mounting bushings 26 are placed in the middle of another workbench 121 on the preparatory side of the second welding workstation 15. An upper arm mounting bracket assembly 291 and an upper arm mounting bracket reinforcing plate 292 are placed on both sides of the other workbench 121 respectively, and then fixed with several clamping mechanisms 122. Then the other workbench 121 is rotated to the welding side, and two welding robots 13 perform welding to obtain the front crossbeam assembly 23 and the two upper arm mounting brackets 29.

[0089] S5: The middle crossbeam assembly 21, the rear crossbeam assembly 22, the front crossbeam assembly 23, the left longitudinal beam 24, and the right longitudinal beam 25 are placed on the workbench 121 on the preparation side of the third welding workstation 16, and then fixed with several clamping mechanisms 122; then the workbench 121 is rotated to the welding side, and two welding robots 13 perform welding to obtain the rear subframe assembly 30.

[0090] S6: Place the rear subframe assembly 30, the two control arm mounting brackets 28 and the two upper arm mounting brackets 29 on another workbench 121 on the preparation side of the third welding workstation 16, and then fix them with several clamping mechanisms 122; then rotate the other workbench 121 to the welding side, and the two welding robots 13 perform welding to obtain the rear subframe assembly 31.

[0091] S7: The rear subframe assembly 31, the two front suspension mounting bracket front plates 33, the two guide arm mounting bracket front plates 34, and the two guide arm mounting bracket rear plates 35 are placed on the workbench 121 on the preparation side of the fourth welding workstation 17, and then fixed with several clamping mechanisms 122; then the workbench 121 is rotated to the welding side, and two welding robots 13 perform welding to obtain the rear subframe assembly 32.

[0092] S8: The rear subframe assembly 32, the two front suspension mounting bracket rear plates 27 and the two tow arm mounting brackets 36 are placed on another workbench 121 on the preparation side of the fourth welding workstation 17, and then fixed with several clamping mechanisms 122; then the workbench 121 is rotated to the welding side, and two welding robots 13 perform welding to obtain the finished product - the automobile rear subframe 2.

[0093] In this embodiment, the welding steps between the various workpieces of the rear subframe 2 of the automobile are divided into eight sequences:

[0094] S1 is the first sequence, which welds together the middle crossbeam assembly 211 and the middle crossbeam assembly 21; S2 is the second sequence, which welds together the rear crossbeam assembly 221 and the rear plate 27 of the front suspension mounting bracket; S3 is the third sequence, which welds together the rear crossbeam assembly 22 and the control arm mounting bracket 28; S4 is the fourth sequence, which welds together the front crossbeam assembly 23 and the upper arm mounting bracket 29; S5 is the fifth sequence, which welds together the rear subframe assembly 30; S6 is the sixth sequence, which welds together the rear subframe assembly 21; S7 is the seventh sequence, which welds together the rear subframe assembly 32; S8 ​​is the eighth sequence, which welds together the finished product - the rear subframe 2 of the automobile.

[0095] This invention divides the welding steps between the various parts of the rear subframe 2 of an automobile into eight sequences, rationally allocates the welding workload of each sequence, reduces the welding time for welding a finished product—the rear subframe 2 of an automobile—and improves its welding efficiency.

[0096] When the workbench 121 on the preparation side is rotated to the welding side for welding in steps S1-S8, at the same time, another workbench 121 on the preparation side is simultaneously manually loaded with workpieces, or the welded workpieces on the other workbench 121 are first unloaded and then reloaded. This allows the workpiece loading cycle and the welding cycle to be independent and do not affect each other, thereby improving the welding efficiency of welding workstation 1.

[0097] After the workpieces in steps S1-S8 are welded, the three-axis positioner 11 of the corresponding welding workstation 1 flips the central axis 111, rotates the worktable 121 located on the welding side to the preparation side, manually unloads the welded workpiece, and then transfers the unloaded workpiece to the welding workstation of the other corresponding steps. The middle crossbeam assembly 21, welded in the first sequence, is transferred to the fifth sequence; the rear crossbeam assembly 221, welded in the second sequence, is transferred to the third sequence; the rear plate 27 of the front suspension mounting bracket, welded in the second sequence, is transferred to the eighth sequence; the rear crossbeam assembly 22, welded in the third sequence, is transferred to the fifth sequence; the control arm mounting bracket 28, welded in the third sequence, is transferred to the sixth sequence; the front crossbeam assembly 23, welded in the fourth sequence, is transferred to the fifth sequence; the upper arm mounting bracket 29, welded in the fourth sequence, is transferred to the sixth sequence; the rear subframe assembly 30, welded in the fifth sequence, is transferred to the sixth sequence; the rear subframe assembly 31, welded in the sixth sequence, is transferred to the seventh sequence; the rear subframe assembly 32, welded in the seventh sequence, is transferred to the eighth sequence; the finished product – the rear subframe 2 of the automobile – is welded in the eighth sequence.

[0098] In this embodiment, refer to the appendix. Figure 3-7The rear subframe 2 of the automobile described in step S8 (i.e., the finished product) is formed by welding the front crossbeam assembly 23, the right longitudinal beam 25, the rear crossbeam assembly 22 and the left longitudinal beam 24 in sequence to form a closed trapezoid, and the length of the front crossbeam assembly 23 is greater than the length of the rear crossbeam assembly 22.

[0099] The middle part of the rear crossbeam assembly 22 is welded to one end of the rear suspension mounting bracket 225, the other end of the rear suspension mounting bracket 225 is welded to the middle part of the middle crossbeam assembly 21, one end of the middle crossbeam assembly 21 is welded to the side of the left longitudinal beam 24 near the rear crossbeam assembly 22, and the other end of the middle crossbeam assembly 21 is welded to the side of the right longitudinal beam 25 near the rear crossbeam assembly 22.

[0100] A rear subframe mounting bushing 26 is welded to each end of the front crossbeam assembly 23 and the rear crossbeam assembly 22; a stabilizer bar mounting bracket 224 is welded to each side of the rear crossbeam assembly 22 near the rear subframe mounting bushing 26, and each stabilizer bar mounting bracket 224 is adjacent to the corresponding rear subframe mounting bushing 26. A first through hole 37 penetrating the rear crossbeam assembly 22 is opened below each stabilizer bar mounting bracket 224; an exhaust pipe hanger 223 is welded to the side of the rear crossbeam assembly 22 near the left longitudinal beam 24 assembly, and the exhaust pipe hanger 223 extends toward the middle crossbeam.

[0101] Each of the left longitudinal beam 24 and the right longitudinal beam 25 has a control arm mounting bracket 28 on its opposite side, and each control arm mounting bracket 28 is close to the front crossbeam assembly 23; each control arm mounting bracket 28 has an upper arm mounting bracket 29 on its side away from the front crossbeam assembly 23.

[0102] The left longitudinal beam 24 and the right longitudinal beam 25 are respectively provided with a guide arm mounting bracket front plate 34 on the back side near the front crossbeam assembly 23, and each of the guide arm mounting bracket front plates 34 is provided with a guide arm mounting bracket rear plate 35 on the side away from the front crossbeam assembly 23.

[0103] A front plate 33 for a front suspension mounting bracket is provided between the opposite side of the left longitudinal beam 24 and the right longitudinal beam 25 and the front crossbeam assembly 23. A rear plate 27 for a front suspension mounting bracket is provided on the side of the front plate 33 away from the front crossbeam assembly 23. A traction arm mounting bracket 36 is provided on the front of the connection between the left longitudinal beam 24 and the right longitudinal beam 25 and the front crossbeam assembly 23.

[0104] A second through hole 38 is provided on both sides of the connection between the middle crossbeam assembly 21 and the rear suspension mounting bracket 225. The second through hole 38 is used to install the lower arm mounting bushing 214. A third through hole 39 is provided on both sides of the middle crossbeam assembly 21 near the left longitudinal beam 24 and the right longitudinal beam 25.

[0105] See attached document Figure 8-9 The first welding workstation 14 in steps S1-S2 has a clamping mechanism 122 on its workbench 121 equipped with the middle crossbeam assembly 211, which includes one A11 clamping mechanism 141, two A12 clamping mechanisms 142, one A13 clamping mechanism 143, two A14 clamping mechanisms 144, two A11 positioning mechanisms 145, two A12 positioning mechanisms 146, and one A11 side-top mechanism 147; the clamping mechanism 122 on its other workbench 121 equipped with the rear crossbeam assembly 22 includes two A21 positioning mechanisms 148, two A22 positioning mechanisms 149, two A21 clamping mechanisms 150, one A22 clamping mechanism 151, two A23 clamping mechanisms 152, two A24 clamping mechanisms 153, and two A25 clamping mechanisms 154.

[0106] Each third through hole 39 of the middle crossbeam assembly 211 is provided with a positioning mechanism 145 of type A11; the clamping mechanism 141 of type A11 is used to clamp the middle part of the middle crossbeam assembly 211, and each clamping mechanism 142 of type A12 is used to clamp one side of the middle crossbeam assembly 211; each of the two side walls of the middle crossbeam assembly 211 is provided with a side support mechanism 147 of type A11 to support the middle crossbeam assembly 211; to prevent the middle crossbeam assembly 211 from loosening or even falling off during the welding process of the middle crossbeam front plate 212 and the middle crossbeam rear plate 213 to form the middle crossbeam assembly 211, which would affect the welding quality of the middle crossbeam assembly 211.

[0107] Each second through hole 38 of the middle crossbeam assembly 21 is provided with a positioning mechanism 146 of No. A12; each clamping mechanism 144 of No. A14 is provided with two clamping parts, which correspond to the adjacent positioning mechanisms 145 of No. A11 and 146 of No. A12 respectively, to clamp the middle crossbeam assembly 21; the clamping mechanism 143 of No. A13 is used to clamp the middle part of the middle crossbeam assembly 21; to prevent the middle crossbeam assembly 211 and the two lower arm mounting bushings 214 from loosening or even falling off during the welding process to form the middle crossbeam assembly 21, which would affect the welding quality of the middle crossbeam assembly 21.

[0108] Each of the rear subframe mounting bushings 26 is fitted onto a corresponding positioning mechanism 148 of number A21. The clamping mechanism 150 of number A21 is used to clamp the rear subframe mounting bushing 26. Each first through hole 37 of the rear crossbeam assembly 221 is provided with a positioning mechanism 149 of number A22. The clamping mechanism 151 of number A22 is used to clamp the exhaust pipe lug 223. The clamping mechanism 152 of number A23 is used to clamp the stabilizer bar mounting bracket 224. Each clamping mechanism 153 of number A24 is used to clamp a front suspension mounting bracket rear plate assembly 271. Each clamping mechanism 154 of number A25 clamps a front suspension mounting bracket reinforcing plate 272. To prevent the rear crossbeam 222, the two rear subframe mounting bushings 26, the exhaust pipe hanger 223, and the two stabilizer bar mounting brackets 224 from loosening or even falling off during the welding process of forming the rear crossbeam assembly 221, the front suspension mounting bracket rear plate assembly 271, and the front suspension mounting bracket reinforcing plate 272, which would affect the welding quality of the rear crossbeam assembly 221 and the front suspension mounting bracket rear plate 27.

[0109] See attached document Figure 10-11 The second welding workstation 15 in steps S3-S4 has a clamping mechanism 122 on its workbench 121 equipped with the rear crossbeam assembly 22, which includes two B11 positioning clamping mechanisms 155, two B11 clamping mechanisms 156, one B12 clamping mechanism 157, one B13 clamping mechanism 158, and two B14 clamping mechanisms 159; the clamping mechanism 122 on its other workbench 121 equipped with the front crossbeam assembly 23 includes two B21 positioning clamping mechanisms 160, two B21 clamping mechanisms 161, two B22 clamping mechanisms 162, and two B23 clamping mechanisms 163.

[0110] Each of the B11 positioning and clamping mechanisms 155 first positions the rear subframe mounting bushing 26 of the rear crossbeam assembly 22, and then clamps the rear subframe mounting bushing 26; each of the B11 clamping mechanisms 156 is used to clamp a stabilizer bar mounting bracket 224; the B12 clamping mechanism 157 clamps the rear suspension mounting bracket 225 from both sides, and the B13 clamping mechanism 158 clamps the rear suspension mounting bracket 225 from the top; each of the B14 clamping mechanisms 159 clamps a control arm mounting bracket 28; to prevent loosening or even falling off during the welding process of the rear crossbeam assembly 221 and the rear suspension mounting bracket 225 to form the rear crossbeam assembly 22, and the control arm mounting bracket front plate 281 and the control arm mounting bracket rear plate 282 to form the control arm mounting bracket 28, which would affect the welding quality of the rear crossbeam assembly 22 and the control arm mounting bracket 28.

[0111] Each of the B21 positioning and clamping mechanisms 160 first positions the rear subframe mounting bushing 26 of the front crossbeam assembly 23, and then clamps the rear subframe mounting bushing 26; each of the B21 clamping mechanisms 161 is positioned close to the corresponding B21 positioning and clamping mechanism 160, and then clamps the front crossbeam assembly 23; each of the B21 clamping mechanisms 161 has a B22 clamping mechanism 162 on the side away from the B21 positioning and clamping mechanism 160, which is used to clamp the front crossbeam assembly 23; each of the B23 clamping mechanisms 163 is used to clamp an upper arm mounting bracket 29. To prevent the front crossbeam 231 and the two rear subframe mounting bushings 26 from loosening or even falling off during the welding process of the upper arm mounting bracket assembly 291 and the upper arm mounting bracket reinforcing plate 292 to form the upper arm mounting bracket 29, thus affecting the welding quality of the front crossbeam assembly 23 and the upper arm mounting bracket 29.

[0112] See attached document Figure 12-13 The third welding workstation 16 in steps S5-S6 has a clamping mechanism 122 on its workbench 121 equipped with the rear subframe assembly 30, which includes four C11 positioning clamping mechanisms 164, two C12 positioning clamping mechanisms 165, two C13 positioning clamping mechanisms 166, one C11 clamping mechanism 167, one C12 clamping mechanism 168, and two C13 clamping mechanisms 169; and a clamping mechanism 122 on its other workbench 121 equipped with the rear subframe assembly 31 includes four C21 positioning clamping mechanisms 170, two C21 clamping mechanisms 171, two C22 clamping mechanisms 172, and two C23 clamping mechanisms 173.

[0113] Each of the aforementioned C11 positioning and clamping mechanisms 164 first positions the rear subframe mounting bushing 26 of the rear subframe assembly 30, and then clamps the rear subframe mounting bushing 26; each of the left longitudinal beam 24 and right longitudinal beam 25 is provided with a C12 positioning and clamping mechanism 165 at one end near the rear crossbeam assembly 22 to clamp the corresponding left longitudinal beam 24 and right longitudinal beam 25; each of the left longitudinal beam 24 and right longitudinal beam 25 is provided with a C13 positioning and clamping mechanism 166 at one end near the front crossbeam assembly 23 to clamp the corresponding left longitudinal beam 24 and right longitudinal beam 25. The beam 25 is clamped; the C11 clamping mechanism 167 is used to clamp the middle part of the front crossbeam assembly 23; the C12 clamping mechanism 168 is used to clamp the rear suspension mounting bracket 225; each of the C13 clamping mechanisms 169 is used to clamp one end of the middle crossbeam assembly 21; to prevent the middle crossbeam assembly 21, rear crossbeam assembly 22, front crossbeam assembly 23, left longitudinal beam 24 and right longitudinal beam 25 from loosening or even falling off during the corresponding welding process to form the rear subframe assembly 30, which would affect the welding quality of the rear subframe assembly 30.

[0114] Each of the C21 positioning and clamping mechanisms 170 first positions the rear subframe mounting bushing 26 of the second rear subframe assembly 31, and then clamps the rear subframe mounting bushing 26; each of the C21 clamping mechanisms 171 is used to clamp a control arm mounting bracket 28; each of the C22 clamping mechanisms 172 is used to clamp an upper arm mounting bracket 29; a C23 clamping mechanism 173 is provided at one end of the left longitudinal beam 24 and the right longitudinal beam 25 near the front crossbeam assembly 23 to clamp the corresponding left longitudinal beam 24 and right longitudinal beam 25. This prevents the rear subframe assembly 30, the two control arm mounting brackets 28, and the two upper arm mounting brackets 29 from loosening or even falling off during the welding process to form the second rear subframe assembly 31, which would affect the welding quality of the second rear subframe assembly 31.

[0115] See attached document Figure 14-15 The fourth welding workstation 17 in steps S7-S8 has a clamping mechanism 122 on the workbench 121 on which the rear subframe assembly 32 is mounted, which includes four D11 positioning clamping mechanisms 174, two D12 positioning clamping mechanisms 175, two D13 positioning clamping mechanisms 176 and two D11 clamping mechanisms 177; and a clamping mechanism 122 on the workbench 121 on which the rear subframe 2 is mounted, which includes four D21 positioning clamping mechanisms 178, two D21 clamping mechanisms 179 and two D22 clamping mechanisms 180.

[0116] Each of the D11 positioning and clamping mechanisms 174 first positions the rear subframe mounting bushing 26 of the rear subframe assembly 32, and then clamps the rear subframe mounting bushing 26; each of the D12 positioning and clamping mechanisms 175 includes two positioning and clamping parts, one of which positions and clamps a guide arm mounting bracket front plate 34; the other positioning and clamping part positions and clamps a guide arm mounting bracket rear plate 35; each of the D13 positioning and clamping mechanisms 176... First, the end closest to the middle crossbeam assembly 21 is positioned, and then the end closest to the middle crossbeam assembly 21 is clamped. Each of the D11 clamping mechanisms 177 is used to clamp a front plate 33 of a front suspension mounting bracket. This prevents the rear subframe assembly 31, the two front plates 33 of the front suspension mounting brackets, the two front plates 34 of the guide arm mounting brackets, and the two rear plates 35 of the guide arm mounting brackets from loosening or even falling off during the welding process to form the rear subframe assembly 32, which would affect the welding quality of the rear subframe assembly 32.

[0117] Each of the D21 positioning and clamping mechanisms 178 first positions the rear subframe mounting bushing 26 of the vehicle's rear subframe 2, and then clamps the rear subframe mounting bushing 26; each of the D21 clamping mechanisms 179 is used to clamp a front suspension mounting bracket rear plate 27; each of the D22 clamping mechanisms 180 is used to clamp a drawbar mounting bracket 36. This prevents loosening or even falling off during the welding process of the rear subframe assembly 32, the two front suspension mounting bracket rear plates 27, and the two drawbar mounting brackets 36 to form the vehicle's rear subframe 2, thus affecting the welding quality of the vehicle's rear subframe 2.

[0118] Obviously, the embodiments described above are merely some embodiments of the present invention, not all embodiments. The accompanying drawings show preferred embodiments of the present invention, but do not limit the patent scope of the present invention. The present invention can be implemented in many different forms; rather, these embodiments are provided to provide a more thorough and complete understanding of the disclosure of the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing specific embodiments, or make equivalent substitutions for some of the technical features. Any equivalent structures made using the content of this specification and drawings, directly or indirectly applied to other related technical fields, are similarly within the patent protection scope of this invention.

Claims

1. A method for producing a rear subframe of an automobile, used in an automobile rear subframe welding production line, the automobile rear subframe welding production line comprising: Four identical welding workstations are arranged and assembled along the axial direction of the three-axis positioner, namely, the first welding workstation, the second welding workstation, the third welding workstation, and the fourth 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. 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 other side of the three-axis positioner away from the welding robots is the welding side. The preparation side is the welding 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, which are used to clamp the workpiece to be welded. The welding robot is equipped with a welding torch, which is used to weld the workpiece clamped on the welding side worktable. The method for producing the rear subframe of an automobile includes the following steps: S1: Place the front plate and rear plate of the middle crossbeam on one side of the workbench of the first welding workstation, and place the welded middle crossbeam assembly and the lower arm mounting bushing on the other side of the workbench. Then fix them with several clamping mechanisms. Then rotate the workbench to the welding side and two welding robots weld to obtain the middle crossbeam assembly and the middle crossbeam assembly. S2: The rear crossbeam, two rear subframe mounting bushings, exhaust pipe hangers, and two stabilizer bar mounting brackets are placed in the middle of another workbench on the preparatory side of the first welding workstation. A front suspension mounting bracket rear plate assembly and a front suspension mounting bracket reinforcing plate are placed on both sides of this other workbench, and then fixed with several clamping mechanisms. Then the other workbench is rotated to the welding side, and two welding robots perform welding to obtain the rear crossbeam assembly and the two front suspension mounting bracket rear plates. S3: Place the rear crossbeam assembly and the rear suspension mounting bracket in the middle of the workbench on the preparation side of the second welding workstation. Place a front plate of the control arm mounting bracket and a rear plate of the control arm mounting bracket on each side of the workbench, and then fix them with several clamping mechanisms. Then rotate the workbench to the welding side, and two welding robots perform welding to obtain the rear crossbeam assembly and two control arm mounting brackets. S4: The front crossbeam and the two rear subframe mounting bushings are placed in the middle of another workbench on the preparatory side of the second welding workstation. On the two sides of this other workbench, an upper arm mounting bracket assembly and an upper arm mounting bracket reinforcing plate are placed respectively, and then fixed with several clamping mechanisms. Then the other workbench is rotated to the welding side, and two welding robots perform welding to obtain the front crossbeam assembly and the two upper arm mounting brackets. S5: Place the middle crossbeam assembly, rear crossbeam assembly, front crossbeam assembly, left longitudinal beam and right longitudinal beam on the workbench on the preparation side of the third welding workstation, and then fix them with several clamping mechanisms; then the workbench is rotated to the welding side, and two welding robots perform welding to obtain the rear subframe assembly. S6: Place the rear subframe assembly one, the two control arm mounting brackets and the two upper arm mounting brackets on another workbench on the preparation side of the third welding workstation, and then fix them with several clamping mechanisms; then rotate the other workbench to the welding side, and the two welding robots perform welding to obtain the rear subframe assembly two. S7: Place the rear subframe assembly II, the front plates of the two front suspension mounting brackets, the front plates of the two guide arm mounting brackets, and the rear plates of the two guide arm mounting brackets on the workbench on the preparation side of the fourth welding workstation, and then fix them with several clamping mechanisms; then rotate the workbench to the welding side, and two welding robots perform welding to obtain the rear subframe assembly III; S8: The rear subframe assembly, the two front suspension mounting bracket rear plates, and the two tow arm mounting brackets are placed on another workbench on the preparatory side of the fourth welding workstation, and then fixed with several clamping mechanisms; then the workbench is rotated to the welding side, and two welding robots perform welding to obtain the finished product - the automobile rear subframe.

2. The method for producing a rear subframe of an automobile according to claim 1, characterized in that, When the workbench on the preparation side is rotated to the welding side for welding in steps S1-S8, at the same time, another workbench on the preparation side is manually loaded, or the workpiece welded on the other workbench is unloaded first and then reloaded.

3. The method for producing a rear subframe of an automobile according to claim 1, characterized in that, After the workpieces in steps S1-S8 are welded, the three-axis positioner of the corresponding welding workstation flips the central axis, rotates the worktable located on the welding side to the preparation side, and the welded workpiece is manually unloaded and then transferred to the welding workstations of the other corresponding steps.

4. The method for producing a rear subframe of an automobile according to claim 1, characterized in that, The rear subframe of the vehicle described in step S8 is formed by welding the front crossbeam assembly, the right longitudinal beam, the rear crossbeam assembly, and the left longitudinal beam in sequence to form a closed trapezoid, and the length of the front crossbeam assembly is greater than the length of the rear crossbeam assembly. The middle part of the rear crossbeam assembly is welded to one end of the rear suspension mounting bracket, the other end of the rear suspension mounting bracket is welded to the middle part of the middle crossbeam assembly, one end of the middle crossbeam assembly is welded to the side of the left longitudinal beam near the rear crossbeam assembly, and the other end of the middle crossbeam assembly is welded to the side of the right longitudinal beam near the rear crossbeam assembly. A rear subframe mounting bushing is welded to each end of the front crossbeam assembly and the rear crossbeam assembly; a stabilizer bar mounting bracket is welded to each side of the rear crossbeam assembly near the rear subframe mounting bushing, and each stabilizer bar mounting bracket is adjacent to the corresponding rear subframe mounting bushing. A first through hole penetrating the rear crossbeam assembly is opened below each stabilizer bar mounting bracket; an exhaust pipe hanger is welded to the side of the rear crossbeam assembly near the left longitudinal beam assembly, and the exhaust pipe hanger extends toward the middle crossbeam. Each of the left and right longitudinal beams has a control arm mounting bracket on its opposite side, and each control arm mounting bracket is close to the front crossbeam assembly; each control arm mounting bracket has an upper arm mounting bracket on its side away from the front crossbeam assembly. The left and right longitudinal beams are each provided with a guide arm mounting bracket front plate on the back side near the front crossbeam assembly, and each guide arm mounting bracket front plate is provided with a guide arm mounting bracket rear plate on the side away from the front crossbeam assembly. A front suspension mounting bracket front plate is provided between the opposite side of the left and right longitudinal beams and the front crossbeam assembly, and a front suspension mounting bracket rear plate is provided on the side of the front suspension mounting bracket away from the front crossbeam assembly. A traction arm mounting bracket is provided on the front of the connection between the left longitudinal beam and the right longitudinal beam and the front cross beam assembly. A second through hole is provided on each side of the connection between the middle crossbeam assembly and the rear suspension mounting bracket. The second through hole is used to install the lower arm mounting bushing. A third through hole is provided on each side of the middle crossbeam assembly near the left and right longitudinal beams.

5. A method for producing a rear subframe of an automobile according to claim 2, characterized in that, The first welding workstation in steps S1-S2 has a clamping mechanism on its workbench equipped with a central crossbeam assembly, which includes one A11 clamping mechanism, two A12 clamping mechanisms, one A13 clamping mechanism, two A14 clamping mechanisms, two A11 positioning mechanisms, two A12 positioning mechanisms, and one A11 side-top mechanism. The clamping mechanism on another workbench equipped with the rear crossbeam assembly includes two A21 positioning mechanisms, two A22 positioning mechanisms, two A21 clamping mechanisms, one A22 clamping mechanism, two A23 clamping mechanisms, two A24 clamping mechanisms, and two A25 clamping mechanisms. Each of the third through holes of the middle crossbeam assembly is provided with a positioning mechanism A11; the clamping mechanism A11 is used to clamp the middle part of the middle crossbeam assembly, and each clamping mechanism A12 is used to clamp one side of the middle crossbeam assembly; each of the two side walls of the middle crossbeam assembly is provided with a side support mechanism A11 to support the middle crossbeam assembly. Each second through hole of the middle crossbeam assembly is provided with a positioning mechanism A12; each clamping mechanism A14 is provided with two clamping parts, which correspond to the adjacent positioning mechanisms A11 and A12 respectively, to clamp the middle crossbeam assembly; the clamping mechanism A13 is used to clamp the middle part of the middle crossbeam assembly. Each of the rear subframe mounting bushings is fitted onto the corresponding positioning mechanism A21, which clamps the rear subframe mounting bushing. Each first through hole of the rear crossbeam assembly is provided with a positioning mechanism A22. The clamping mechanism A22 clamps the exhaust pipe lug. The clamping mechanism A23 clamps the stabilizer bar mounting bracket. Each clamping mechanism A24 clamps a front suspension mounting bracket rear plate assembly. Each clamping mechanism A25 clamps a front suspension mounting bracket reinforcement plate.

6. A method for producing a rear subframe of an automobile according to claim 2, characterized in that, The second welding workstation in steps S3-S4 has a clamping mechanism on its workbench equipped with the rear crossbeam assembly, which includes two B11 positioning clamping mechanisms, two B11 clamping mechanisms, one B12 clamping mechanism, one B13 clamping mechanism, and two B14 clamping mechanisms. The clamping mechanism on another workbench equipped with the front crossbeam assembly includes two B21 positioning clamping mechanisms, two B21 clamping mechanisms, two B22 clamping mechanisms, and two B23 clamping mechanisms. Each of the B11 positioning and clamping mechanisms first positions the rear subframe mounting bushing of the rear crossbeam assembly, and then clamps the rear subframe mounting bushing; each of the B11 clamping mechanisms is used to clamp a stabilizer bar mounting bracket; the B12 clamping mechanism clamps the rear suspension mounting bracket from both sides, and the B13 clamping mechanism clamps the rear suspension mounting bracket from the top; each of the B14 clamping mechanisms clamps a control arm mounting bracket. Each of the B21 positioning and clamping mechanisms first positions the rear subframe mounting bushing of the front crossbeam assembly, and then clamps the rear subframe mounting bushing; each of the B21 clamping mechanisms is located close to the corresponding B21 positioning and clamping mechanism, and then clamps the front crossbeam assembly; each of the B21 clamping mechanisms has a B22 clamping mechanism on the side away from the B21 positioning and clamping mechanism, which is used to clamp the front crossbeam assembly; each of the B23 clamping mechanisms is used to clamp an upper arm mounting bracket.

7. A method for producing a rear subframe of an automobile according to claim 2, characterized in that, The third welding workstation in steps S5-S6 has a clamping mechanism on its workbench equipped with the rear subframe assembly, which includes four C11 positioning clamping mechanisms, two C12 positioning clamping mechanisms, two C13 positioning clamping mechanisms, one C11 clamping mechanism, one C12 clamping mechanism, and two C13 clamping mechanisms. The clamping mechanism on another workbench equipped with the second rear subframe assembly includes four C21 positioning clamping mechanisms, two C21 clamping mechanisms, two C22 clamping mechanisms, and two C23 clamping mechanisms. Each of the C11 positioning and clamping mechanisms first positions the subframe mounting bushing of the rear subframe assembly, and then clamps the rear subframe mounting bushing; each of the left and right longitudinal beams is provided with a C12 positioning and clamping mechanism at one end near the rear crossbeam assembly to clamp the corresponding left and right longitudinal beams; each of the left and right longitudinal beams is provided with a C13 positioning and clamping mechanism at one end near the front crossbeam assembly to clamp the corresponding left and right longitudinal beams; the C11 clamping mechanism is used to clamp the middle part of the front crossbeam assembly; the C12 clamping mechanism is used to clamp the rear suspension mounting bracket; each of the C13 clamping mechanisms is used to clamp one end of the middle crossbeam assembly; Each of the C21 positioning and clamping mechanisms first positions the subframe mounting bushing of the second rear subframe assembly, and then clamps the rear subframe mounting bushing; each of the C21 clamping mechanisms is used to clamp a control arm mounting bracket; each of the C22 clamping mechanisms is used to clamp an upper arm mounting bracket; each of the left and right longitudinal beams is provided with a C23 positioning and clamping mechanism at one end near the front crossbeam assembly to clamp the corresponding left and right longitudinal beams.

8. A method for producing a rear subframe of an automobile according to claim 2, characterized in that, The fourth welding workstation in steps S7-S8 has a clamping mechanism on its workbench equipped with the rear subframe assembly three, which includes four D11 positioning clamping mechanisms, two D12 positioning clamping mechanisms, two D13 positioning clamping mechanisms, and two D11 clamping mechanisms. The clamping mechanism on the workbench equipped with the rear subframe of the vehicle includes four D21 positioning clamping mechanisms, two D21 clamping mechanisms, and two D22 clamping mechanisms. Each of the D11 positioning and clamping mechanisms first positions the rear subframe mounting bushing of the rear subframe assembly three, and then clamps the rear subframe mounting bushing; each of the D12 positioning and clamping mechanisms includes two positioning and clamping parts, one of which positions and clamps a guide arm mounting bracket front plate; the other positioning and clamping part positions and clamps a guide arm mounting bracket rear plate; each of the D13 positioning and clamping mechanisms first positions one end near the center crossbeam assembly, and then clamps that end near the center crossbeam assembly; each of the D11 clamping mechanisms is used to clamp a front suspension mounting bracket front plate; Each of the D21 positioning and clamping mechanisms first positions the rear subframe mounting bushing of the vehicle's rear subframe, and then clamps the rear subframe mounting bushing; each of the D21 clamping mechanisms is used to clamp a front suspension mounting bracket rear plate; each of the D22 clamping mechanisms is used to clamp a tow arm mounting bracket.

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