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EP-4737055-A1 - ALIGNMENT AND CLAMPING TOOLING FOR AUTOMATIC ASSEMBLY WELDING OF VEHICLE DOOR RING, AND WELD SEAM ALIGNMENT METHOD THEREFOR

EP4737055A1EP 4737055 A1EP4737055 A1EP 4737055A1EP-4737055-A1

Abstract

The present disclosure relates to an alignment clamping fixture for automatic tailor welding of an automotive door ring and a welded seam alignment method therefor. The alignment clamping fixture for automatic tailor welding of an automotive door ring includes a gripper unit and a clamp unit, where the gripper unit is connected to a working end of a robotic arm; the gripper unit includes a gripper frame, and a plurality of vision camera mechanisms and a plurality of suction cup mechanisms are mounted at a bottom of the gripper frame in a fit manner, respectively; and the clamp unit includes a clamp base, a plurality of first alignment mechanisms are mounted at a top of the clamp base in a fit manner, the first alignment mechanisms are configured to clamp a workpiece, a light source is arranged in an individual first alignment mechanism, and the light source illuminates the workpiece from a back surface of the workpiece, so that the vision camera mechanisms position welded seams on the workpiece. The alignment clamping fixture for automatic tailor welding of an automotive door ring features high use flexibility, can realize flexible and automatic alignment and assembling of the welded seams, is high in stability and operation continuity, and is high in alignment accuracy and good in assembling quality.

Inventors

  • FAN, Weiguo
  • HAN, Xichun
  • JIA, Jiqing
  • WANG, Zi
  • YANG, Qiuye
  • REN, Chao

Assignees

  • Wuxi Siasun Robot & Automation Co., Ltd.

Dates

Publication Date
20260506
Application Date
20240819

Claims (10)

  1. An alignment clamping fixture for automatic tailor welding of an automotive door ring, comprising: a gripper unit and a clamp unit, wherein the gripper unit is connected to a working end of a robotic arm; the gripper unit comprises a gripper frame (2), a plurality of vision camera mechanisms (3) and a plurality of suction cup mechanisms (6) are mounted at a bottom of the gripper frame (2) in a fit manner, respectively, the gripper unit takes photos of welded seams on a workpiece (12) by the vision camera mechanisms (3), and the gripper unit sucks up the workpiece (12) by the suction cup mechanisms (6), so that the workpiece (12) is carried to a target work station of the clamp unit by the robotic arm; and the clamp unit comprises a clamp base (7), a plurality of first alignment mechanisms (8) are mounted at a top of the clamp base (7) in a fit manner, the first alignment mechanisms (8) are configured to clamp the workpiece (12), a light source (803) is arranged in each individual first alignment mechanism (8), the light source (803) is disposed below the workpiece (12), and the light source (803) illuminates the workpiece (12) from a back surface of the workpiece (12), so that the vision camera mechanisms (3) position the welded seams on the workpiece (12).
  2. The alignment clamping fixture for automatic tailor welding of an automotive door ring according to claim 1, wherein a structure of an individual first alignment mechanism (8) comprises: a first mounting base (801), wherein at least one first switch magnetic base (802) is fixed on the first mounting base (801), the first alignment mechanism (8) is in quick-release connection to the clamp base (7) by the first switch magnetic base (802), a connecting base (804) is fixed at a top of the first mounting base (801), a telescopic air cylinder (805) is fixed on the connecting base (804), an output end of the telescopic air cylinder (805) is connected to the light source (803), a base plate (807) is fixed at a top of the connecting base (804), a strip-shaped through hole is formed in an end surface of the base plate (807), a plurality of electromagnets (806) are mounted in a spaced manner at a top of the base plate (807), a light-transmitting gap (809) is formed between two adjacent electromagnets (806), and the light-transmitting gap (809) is disposed corresponding to the strip-shaped through hole; and the telescopic air cylinder (805) drives the light source (803) to perform a linear motion, so that the light source (803) illuminates the workpiece (12) from the back surface of the workpiece (12) through the light-transmitting gap (809).
  3. The alignment clamping fixture for automatic tailor welding of an automotive door ring according to claim 1, wherein a fixing plate group (4) is fixed at the bottom of the gripper frame (2), the fixing plate group (4) comprises a plurality of first fixing plates and a plurality of second fixing plates, and at least one suction cup mechanism (6) is mounted on each of the first fixing plates and the second fixing plates in a fit manner; and for an individual first fixing plate, at least one vision camera mechanism (3) and pressing finger mechanisms (5) disposed in one-to-one correspondence to the vision camera mechanisms (3) are further mounted in a fit manner.
  4. The alignment clamping fixture for automatic tailor welding of an automotive door ring according to claim 3, wherein a structure of an individual vision camera mechanism (3) comprises: a camera mounting plate (301), wherein a vision camera (302) is fixed on the camera mounting plate (301), a plurality of first quick locking devices (303) are disposed on the camera mounting plate (301) around the vision camera (302), the vision camera mechanism (3) is in quick-release connection to the first fixing plate by the first quick locking devices (303), a first fixing pin hole (305) and a second fixing pin hole (306) are formed in an end surface of each of the camera mounting plates (301), respectively, and the vision camera mechanism (3) is positioned at a mounting position on the first fixing plate by the first fixing pin hole (305) and the second fixing pin hole (306).
  5. The alignment clamping fixture for automatic tailor welding of an automotive door ring according to claim 3, wherein a structure of an individual pressing finger mechanism (5) comprises: a pressing finger mounting base (501), wherein a plurality of second quick locking devices (505) are fixed on the pressing finger mounting base (501), the pressing finger mechanism (5) is in quick-release connection to the first fixing plate by the second quick locking devices (505), a plurality of pressing finger air cylinders (502) are fixed at a bottom of the pressing finger mounting base (501), and an output end of an individual pressing finger air cylinder (502) is connected to a universal ball head screw (503); and the pressing finger air cylinder (502) drives a corresponding universal ball head screw (503) to extend, so that a universal ball corresponding to the universal ball head screw (503) leans against the workpiece (12).
  6. The alignment clamping fixture for automatic tailor welding of an automotive door ring according to claim 3, wherein a structure of an individual suction cup mechanism (6) comprises: a suction cup mounting base (601), wherein the suction cup mounting base (601) is mounted with the fixing plate group (4) in a fit manner by a rotary plunger (605), a suction cup (602) is mounted at a bottom of the suction cup mounting base (601) in a fit manner by a spring rod (603), a suction cup air pipe joint (604) for connecting an external air source is mounted at a top of the suction cup mounting base (601) in a fit manner, and the external air source drives the suction cup (602) by the suction cup air pipe joint (604) to suck up the workpiece (12).
  7. The alignment clamping fixture for automatic tailor welding of an automotive door ring according to claim 1, wherein the gripper unit is mounted with the working end of the robotic arm in a fit manner by a gripper quick-change mechanism (1), and a structure of the gripper quick-change mechanism (1) comprises: a quick-change mounting plate (101), wherein a planar quick-change mounting surface (102) is arranged on a top end surface of the quick-change mounting plate (101), and the gripper quick-change mechanism (1) is in fit connection to the working end of the robotic arm by the quick-change mounting surface (102); and a plurality of quick-change locking devices (104) and a plurality of quick-change locating pins (103) are mounted at a bottom of the quick-change mounting plate (101) in a fit manner, and the gripper quick-change mechanism (1) is in locking connection to the gripper frame (2) by the quick-change locking devices (104).
  8. The alignment clamping fixture for automatic tailor welding of an automotive door ring according to claim 1, wherein a positioning fixture (10) is fixed at the top of the clamp base (7), the positioning fixture (10) is configured to position arrangement positions of the first alignment mechanisms (8), the positioning fixture (10) comprises a mounting bracket (1002), a positioning plate (1001)is fixed at a top of the mounting bracket (1002), a plurality of spaced positioning notches (1003) are arranged at an edge of the positioning plate (1001), and the positioning notches (1003) are in one-to-one correspondence to the first alignment mechanisms (8).
  9. The alignment clamping fixture for automatic tailor welding of an automotive door ring according to claim 6, wherein a plurality of supporting mechanisms (11) for supporting the workpiece (12) are further mounted at the top of the clamp base (7) in a fit manner, and a structure of an individual supporting mechanism (11) comprises: a second mounting base (1101), wherein at least one second switch magnetic base (1102) is fixed at a bottom of the second mounting base (1101), the supporting mechanism (11) is in quick-release connection to the clamp base (7) by the second switch magnetic base (1102), a plurality of supporting columns (1103) are fixed at a top of the second mounting base (1101), and a nylon plate (1104) is mounted at tops of all the supporting columns (1103).
  10. A welded seam alignment method based on the alignment clamping fixture for automatic tailor welding of an automotive door ring according to claim 1, comprising the following steps: first step: preparation: placing each steel plate in the workpiece (12) in place by a robot; second step: driving, by the robotic arm, the gripper unit to move to a position above the workpiece (12) placed in place, sucking, by the gripper unit, the workpiece (12) placed in place by the suction cup mechanism (6), and then transferring, by the robotic arm, the workpiece (12) by the gripper unit, wherein when each of the welded seams on the workpiece (12) corresponds to the light-transmitting gap (809) in each of the first alignment mechanisms (8), it indicates that the robotic arm transfers the workpiece (12) to the target work station of the clamp unit, and then the suction cup mechanism (6) releases the workpiece (12); third step: driving, by the robotic arm, the gripper unit to lift to a height, so that a distance between a lens of the vision camera (302) in the vision camera mechanism (3) and an upper surface of the workpiece (12) is equal to a focal distance of the vision camera (302), and then extending each of the pressing finger air cylinders (502) in the pressing finger mechanism (5) simultaneously to drive the corresponding universal ball head screw (503) to lean against the upper surface of the workpiece (12); fourth step: extending the telescopic air cylinder (805) in each of the first alignment mechanisms (8) simultaneously to drive the corresponding light source (803) to move to a position directly facing the light-transmitting gap (809), so that the light source (803) illuminates the corresponding welded seam; fifth step: taking, by the vision camera (302), photos at both ends of each of the welded seams and transferring photo data to an industrial personal computer, and calculating, by the industrial personal computer, a gap of each of the welded seams according to the photo data and calculating differences among gaps of different welded seams; and calculating, by the industrial personal computer, a target position of each of the steel plates in the workpiece (12) according to the gap of each of the welded seams, the differences among the gaps of different welded seams, and a welding requirement; and sixth step: adjusting, by the second alignment mechanism (9), each of the steel plates in the workpiece (12) to the target position, then taking, by the vision camera (302), photos at both ends of each of the welded seams again, and determining, by the industrial personal computer, whether each of the welded seams in the workpiece (12) is aligned according to the photo data taken by the vision camera (302) again, wherein when each of the welded seams in the workpiece (12) is aligned, each of the pressing finger mechanisms (5) releases the workpiece (12), and the light source (803) in each of the first alignment mechanisms (8) retracts to an initial position; and when each of the welded seams in the workpiece (12) is not aligned, the fifth step and the sixth step are repeated until each of the welded seams in the workpiece (12) is aligned.

Description

TECHNICAL FIELD The present disclosure relates to the technical field of automobile manufacturing, and in particular, to an alignment clamping fixture for automatic tailor welding of an automotive door ring and a welded seam alignment method therefor. BACKGROUND An automotive door ring is formed by assembling and welding a plurality of door ring plates. Before laser welding, the door ring plates need to be placed in place and positioned, which facilitates subsequent automatic welding by a laser welding machine. The positioning accuracy of the door ring plates before welding directly affects the subsequent welding quality of the automotive door ring. In the related art, a Chinese Patent CN114713983A discloses an automatic assembly fixture for a laser welded steel plate of an automotive door ring and an operation method. A vision camera mechanism and a welding driving mechanism are disposed, so that a welded seam between two adjacent steel plates can be adjusted. After the welded seam is adjusted to be in place, the steel plates are positioned by using an electromagnetic assembling component, thereby ensuring the welding quality of the door ring. However, the foregoing automatic assembly fixture for a laser welded steel plate of an automotive door ring has the following problems: (1) All mechanisms and components in the foregoing automatic assembly fixture are fixed on a base plate, causing that parts are placed too compactly. When a door ring with four or more welded seams is assembled, a problem that the steel plates cannot be placed is caused. Therefore, the automatic assembly fixture is difficult to apply to the assembly of all door ring types.(2) For the vision camera mechanism in the foregoing automatic assembly fixture, the vision camera is fixed on a rotary driving device. The rotary driving device is fixed on a lift driving device. That is, the vision camera is supported by a cantilever. The longer the cantilever is, the lower the fixed position accuracy is, resulting in that repeated positioning accuracy of the vision camera cannot reach 0.02 mm. Finally, the door ring assembling quality is reduced and the rate of finished products is low. In addition, the structures of the rotary driving device and the lift driving device are complex, and high in failure rate, causing poor equipment operation continuity.(3) When the foregoing automatic assembly fixture aligns the steel panels, an auxiliary light source usually needs to be disposed beside the camera for illustration, and an integrated light source is disposed on a vision camera component in a vision camera mechanism to directly projects light onto the steel plates. However, the surfaces of the steel plates used for making the door ring are usually covered with various coatings, and thus reflection conditions are different. When light is projected directly, side lines of the steel plates are blurred. In this case, it is needed to frequently adjust exposure parameters of the vision camera component, so that the operation is tedious, and the assembling quality is reduced. To sum up, in an assembling mode used by the foregoing automatic assembly fixture, a mechanical pushing method is used to implement alignment of the welded steel plates. Then welding is performed at a welding position. Because the outer contour shape of each single piece of a closed-loop welded component such as the door ring slightly deviates, when a closed door ring is spliced, a tolerance is finally accumulated to a last welded seam, resulting in a gap left at one end of the last welded seam, and finally cannot satisfy a requirement of a welding process.*** Moreover, in the foregoing automatic assembly fixture, the repeated positioning accuracy of the rotary driving device and the life driving device is low. Similarly, a requirement that the positioning accuracy of the steel plates is less than ±0.05 mm cannot be met. Therefore, the steel plates can only be forcibly close to each other, causing a condition in which the gap is left at one end of the last welded seam. SUMMARY Technical Problems In view of the foregoing disadvantages in the existing production technology, this applicant provides an alignment clamping fixture for automatic tailor welding of an automotive door ring and a welded seam alignment method therefor. The alignment clamping fixture for automatic tailor welding of an automotive door ring features high use flexibility, can realize flexible and automatic alignment and assembling of the welded seams, is high in stability and operation continuity, and is high in alignment accuracy and good in assembling quality. Technical Solutions The present disclosure adopts the following technical solution: An alignment clamping fixture for automatic tailor welding of an automotive door ring includes a gripper unit and a clamp unit, where the gripper unit is connected to a working end of a robotic arm;the gripper unit includes a gripper frame, a plurality of vision camera mechani