Alignment clamping tool for automatic tailor welding of automobile door rings and its weld alignment method

Abstract

The present invention relates to an alignment clamping tool for automatic welding of automobile door rings and a weld alignment method thereof. An alignment clamping tool for automatic welding of automobile door rings comprises a gripper unit and a clamping unit, wherein the gripper unit is connected to the working end of a robotic arm; the gripper unit comprises a gripper frame, and the bottom of the gripper frame is respectively equipped with a plurality of visual camera mechanisms and a plurality of suction cup mechanisms; the clamping unit comprises a clamping base, and the top of the clamping base is equipped with a plurality of first alignment mechanisms, wherein the first alignment mechanism is used to clamp a workpiece, and a light source is provided in a single first alignment mechanism, and the light source illuminates the workpiece from the back of the workpiece, thereby enabling the visual camera mechanism to locate the weld on the workpiece. It has high flexibility in use, can realize flexible automatic alignment and splicing of welds, has high equipment stability, and high equipment operation continuity; at the same time, it has high alignment accuracy and good splicing quality.

Description

Technical Field

[0001] The invention relates to the technical field of automobile manufacturing, in particular to an alignment clamping tool for automatic tailor welding of automobile door rings and a weld alignment method thereof. Background Art

[0002] Automobile door rings are made by welding together several door ring plates. Before laser welding, the door ring plates need to be positioned and aligned to facilitate the subsequent automated welding process using the laser welding machine. The positioning accuracy of the door ring plates before welding directly affects the subsequent welding quality of the automobile door ring.

[0003] In related technologies, Chinese patent CN114713983A discloses an automatic assembly fixture and operation method for laser-welded steel plates for automobile door rings. By setting a visual camera mechanism and a welding drive mechanism, the weld between two adjacent steel plates can be adjusted. After adjustment, the steel plates are positioned through an electromagnet assembly component to ensure the welding quality of the door ring.

[0004] However, the aforementioned automatic assembly fixture for laser-welded steel plates for automobile door rings has the following problems:

[0005] (1) All the mechanisms and components in the above-mentioned automatic assembly fixture are fixed on the base plate, resulting in the parts being placed too compactly. When assembling door rings with more than 4 welds, the steel plates cannot be placed properly, making it difficult to assemble all door ring types.

[0006] (2) With respect to the visual camera mechanism in the above-mentioned automatic assembly fixture, the visual camera is fixed on the rotary drive device, and the rotary drive device is fixed on the lifting drive device, that is, the visual camera adopts a cantilever support method. The longer the cantilever, the lower the fixed position accuracy, resulting in the visual camera's repeated positioning accuracy unable to reach 0.02mm, which ultimately leads to a decrease in the door ring assembly quality and a low yield rate. At the same time, the structures of the rotary drive device and the lifting drive device are complex and the failure rate is high, resulting in poor continuity of equipment operation.

[0007] (3) When the above-mentioned automatic assembly fixture is used to align the steel plates, it is usually necessary to set up an auxiliary light source next to the camera for lighting. The visual camera component in the visual camera mechanism is provided with an integrated light source, which illuminates the steel plate in a front projection manner. However, the surface of the steel plate used to make the door knocker is usually covered with various coatings, and the reflective conditions vary. The front projection lighting causes the edge of the steel plate to be blurred. At this time, it is necessary to frequently adjust the exposure parameters of the visual camera component, which is cumbersome to operate and also leads to a decrease in the quality of the assembly.

[0008] To sum up, the assembly method adopted by the above-mentioned automatic assembly fixture is to achieve the alignment of the welded steel plates by mechanical pushing and blocking, and then to the welding position for welding. Since the outer contour shape of each single piece of closed-loop welded parts such as door rings has a slight deviation, when they are assembled into a closed door ring, the tolerance will eventually be accumulated to the last seam, resulting in a gap at one end of the last seam, and ultimately unable to meet the requirements of the welding process; at the same time, in the above-mentioned automatic assembly fixture, the repeatability positioning accuracy of the rotation drive device and the lifting drive device is low, and the requirement of steel plate positioning accuracy of less than ±0.05mm cannot be achieved. The steel plates can only be forced close to each other, resulting in a gap at one end of the last seam. Summary of the Invention

[0009] In response to the shortcomings of the above-mentioned existing production technology, the applicant provides a positioning clamping tool for automatic welding of automobile door rings and a weld alignment method thereof. The tool has high flexibility in use, can realize flexible automatic positioning and splicing of welds, has high equipment stability and high equipment operation continuity; at the same time, it has high positioning accuracy and good splicing quality.

[0010] The technical solutions adopted in the present invention are as follows:

[0011] A positioning clamping tool for automatic tailor-welding of automobile door rings, comprising a gripper unit and a clamping unit, wherein the gripper unit is connected to the working end of a robotic arm;

[0012] The gripper unit includes a gripper frame, and the bottom of the gripper frame is respectively equipped with several visual camera mechanisms and several suction cup mechanisms. The gripper unit takes pictures of the welds on the workpiece through the visual camera mechanism, and the gripper unit sucks up the workpiece through the suction cup mechanism, thereby transporting the workpiece to the target working position of the clamp unit through the robotic arm;

[0013] The fixture unit includes a fixture base, and several first alignment mechanisms are installed on the top of the fixture base. The first alignment mechanisms are used to clamp the workpiece. A light source is provided in a single first alignment mechanism. The light source is arranged below the workpiece. The light source illuminates the workpiece from the back of the workpiece, so that the visual camera mechanism locates the weld on the workpiece.

[0014] As a further improvement of the above technical solution:

[0015] The structure of a single first alignment mechanism is as follows: it includes a first mounting base, at least one first switch magnetic base is fixed on the first mounting base, the first alignment mechanism is quickly connected to the fixture base through the first switch magnetic base, a connecting base is fixed on the top of the first mounting base, a telescopic cylinder is fixed on the connecting base, the output end of the telescopic cylinder is connected to a light source, a seat plate is fixed on the top of the connecting base, a strip-shaped through hole is opened on the end surface of the seat plate, and a plurality of electromagnets are installed on the top of the seat plate at intervals, forming a light-transmitting gap between adjacent two electromagnets, and the light-transmitting gap is arranged corresponding to the strip-shaped through hole;

[0016] The telescopic cylinder drives the light source to move linearly, so that the light source illuminates the workpiece from the back side through the light-transmitting gap.

[0017] The structure of a single first alignment mechanism is as follows: it includes a first mounting base, at least one first switch magnetic base is fixed on the first mounting base, the first alignment mechanism is quickly connected to the fixture base through the first switch magnetic base, a connecting base is fixed on the top of the first mounting base, a telescopic cylinder is fixed on the connecting base, the output end of the telescopic cylinder is connected to a light source, a seat plate is fixed on the top of the connecting base, a strip-shaped through hole is opened on the end surface of the seat plate, and a plurality of electromagnets are installed on the top of the seat plate at intervals, forming a light-transmitting gap between adjacent two electromagnets, and the light-transmitting gap is arranged corresponding to the strip-shaped through hole;

[0018] The telescopic cylinder drives the light source to move linearly, so that the light source illuminates the workpiece from the back side through the light-transmitting gap.

[0019] A fixing plate group is fixed to the bottom of the gripper frame, and the fixing plate group includes a plurality of first fixing plates and a plurality of second fixing plates, and each of the first fixing plates and the second fixing plates is cooperatively mounted with at least one suction cup mechanism;

[0020] For a single first fixing plate, at least one visual camera mechanism and a finger pressing mechanism arranged in one-to-one correspondence with the visual camera mechanism are also installed.

[0021] The structure of a single visual camera mechanism is as follows: it includes a camera mounting plate, a visual camera is fixed on the camera mounting plate, and several first quick locks are arranged on the camera mounting plates around the visual camera. The visual camera mechanism is quickly connected to the first fixing plate through the first quick locks, and a first fixing pin hole and a second fixing pin hole are respectively provided on the end surface of the camera mounting plate. The visual camera mechanism is positioned at the installation position on the first fixing plate through the first fixing pin hole and the second fixing pin hole.

[0022] The structure of a single finger pressing mechanism is as follows: it includes a finger pressing mounting base, on which a plurality of second quick lockers are fixed, and the finger pressing mechanism is quickly connected to the first fixing plate through the second quick lockers. A plurality of finger pressing cylinders are fixed to the bottom of the finger pressing mounting base, and the output end of each finger pressing cylinder is connected to a universal ball screw.

[0023] The finger-pressing cylinder drives the corresponding universal ball screw to extend, so that the universal ball of the corresponding universal ball screw presses against the workpiece.

[0024] The structure of a single suction cup mechanism is as follows: it includes a suction cup mounting seat, which is installed in cooperation with the fixed plate group through a rotating plunger, the bottom of the suction cup mounting seat is installed with a suction cup through a spring rod, and the top of the suction cup mounting seat is installed with a suction cup air pipe joint for connecting to an external air source, and the external air source drives the suction cup to suck up the workpiece through the suction cup air pipe joint.

[0025] The gripper unit is mounted in cooperation with the working end of the robotic arm through a gripper quick-change mechanism. The gripper quick-change mechanism comprises a quick-change mounting plate, the top end surface of which is provided with a planar quick-change mounting surface. The gripper quick-change mechanism is connected to the working end of the robotic arm through the quick-change mounting surface.

[0026] The bottom of the quick-change mounting plate is cooperatively mounted with a plurality of quick-change lockers and a plurality of quick-change positioning pins, and the gripper quick-change mechanism is locked and connected with the gripper frame through the quick-change lockers.

[0027] A positioning tool is fixed on the top of the clamp base, and the positioning tool is used to locate the layout position of the first alignment mechanism. The positioning tool includes a mounting bracket, and a positioning plate is fixed on the top of the mounting bracket. The edge of the positioning plate is provided with several positioning angles arranged at intervals, and the positioning angles correspond one-to-one to the first alignment mechanism.

[0028] The top of the clamp base is also equipped with several supporting mechanisms for supporting the workpiece. The structure of a single supporting mechanism is: it includes a second mounting base, at least one second switch magnetic base is fixed to the bottom of the second mounting base, the supporting mechanism is quickly connected to the clamp base through the second switch magnetic base, and several supporting columns are fixed on the top of the second mounting base, and a nylon plate is also installed on the top of the support column.

[0029] A weld alignment method based on the above-mentioned alignment clamping tool for automatic tailor-welding of automobile door rings comprises the following steps:

[0030] Step 1: Preparation: Use the robot to place the steel plates in the workpiece in place;

[0031] Step 2: The robotic arm drives the gripper unit to move to the top of the workpiece. The gripper unit uses the suction cup mechanism to hold the workpiece in place. The robotic arm then transfers the workpiece through the gripper unit.

[0032] When each weld seam on the workpiece corresponds to the light-transmitting gap in each first alignment mechanism, the robot arm moves the workpiece to the target working position of the fixture unit, and then the suction cup mechanism releases the workpiece;

[0033] Step 3: The robotic arm drives the gripper unit to a certain height, so that the distance between the visual camera lens in the visual camera mechanism and the upper surface of the workpiece is equal to the focal length of the visual camera. Then, the finger-pressing cylinders in the finger-pressing mechanism extend simultaneously, driving the corresponding universal ball screw to press against the upper surface of the workpiece.

[0034] Step 4: The telescopic cylinders in each first alignment mechanism extend simultaneously, driving the corresponding light source to move to face the light-transmitting gap, so that the light source illuminates the corresponding weld;

[0035] Step 5: Use a visual camera to take photos of the two ends of each weld and transmit the photo data to the industrial computer. The industrial computer calculates the gap of each weld based on the photo data and calculates the difference between the gaps of different welds;

[0036] Based on the gaps of each weld, the difference between the gaps of different welds, and the welding requirements, the industrial computer calculates the target position of each steel plate in the workpiece;

[0037] Step 6: The second alignment mechanism adjusts each steel plate in the workpiece to the target position. Subsequently, the visual camera takes photos of the two ends of each weld again. The industrial computer determines whether the alignment of each weld in the workpiece is completed based on the photo data taken by the visual camera again.

[0038] When the alignment of each weld seam in the workpiece is completed, each finger pressing mechanism releases the workpiece, and the light source in each first alignment mechanism retracts to the initial position;

[0039] When the alignment of the weld seams in the workpiece is not completed, repeat steps 5 and 6 until the alignment of the weld seams in the workpiece is completed.

[0040] The beneficial effects of the present invention are as follows:

[0041] The alignment clamping tooling for automatic welding of automobile door knockers of the present invention has a compact and reasonable structure and is easy to operate. By providing a gripper unit, the positional uniqueness of each mechanism therein can be ensured, the overall working stability of the equipment can be increased, and the positioning accuracy of the visual camera can be improved. For door knockers of different versions, the corresponding gripper unit can be quickly and directly replaced through the gripper quick-release mechanism, which facilitates layout, reduces design difficulty, simplifies the focusing operation of the visual camera, and improves work efficiency.

[0042] The positioning clamping tool for automatic welding of automobile door knockers of the present invention has a unique arrangement of the gripper frame and the fixed plate group on the gripper frame in the gripper unit, which can improve the accuracy and stability of the visual camera. Its structure is stable and reliable, with a low failure rate, and can effectively improve the repeatability of the visual camera. At the same time, the visual camera mechanism, the finger pressing mechanism, and the suction cup mechanism in the gripper unit are universal and highly interchangeable. When processing door knockers of other types, only the gripper frame and the fixed plate group can be replaced, and the visual camera mechanism, the finger pressing mechanism, and the suction cup mechanism can be reused, thereby reducing production costs.

[0043] The alignment clamping tooling for automatic welding of automobile door knockers of the present invention can realize rapid assembly and disassembly of the visual camera mechanism, the finger pressing mechanism, the suction cup mechanism, the first alignment mechanism and the supporting mechanism, thereby realizing flexible switching for door knockers of different versions, having high flexibility of use and good compatibility.

[0044] The positioning clamping tool for automatic welding of automobile door rings of the present invention has a visual camera mechanism with a pixel of not less than 20 million pixels. By illuminating the light source in the first positioning mechanism from the back of the workpiece, the influence of the workpiece coating on the visual camera can be avoided, so that the workpiece with any coating can have a clear edge line, so that the recognition accuracy of the visual camera reaches 0.02mm. By cooperating with the second positioning mechanism, the positioning accuracy of each steel plate in the workpiece can reach ≤±0.05mm, and finally the tolerance between the welds in the workpiece is evenly distributed to each weld, so that the gap tolerance between each weld is maintained within 0.1mm, meeting the high-precision welding process requirements.

[0045] The weld alignment method of the present invention can calculate the target position of each steel plate in the workpiece by setting a visual camera mechanism and an industrial computer, thereby evenly distributing the deviations between different welds to each weld, reducing the requirements of high-quality door rings on sheet materials, improving the yield rate, and improving welding accuracy; at the same time, by detecting the gaps in the welds through the visual camera mechanism, it can prevent defective products from flowing into the welding process, avoid wasting sheet materials, and improve the yield rate. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] Figure 1 It is a structural schematic diagram of the present invention.

[0047] Figure 2 for Figure 1 Top view of .

[0048] Figure 3 It is a structural diagram of the gripper quick-change mechanism in the present invention.

[0049] Figure 4Schematic diagram of the structure of the gripper unit in the present invention (the gripper quick-change mechanism is omitted).

[0050] Figure 5 Schematic diagram of the installation structure of the fixed plate group in the present invention.

[0051] Figure 6 Schematic diagram of the structure of the visual camera mechanism in the present invention.

[0052] Figure 7 It is a structural diagram of the finger pressing mechanism in the present invention.

[0053] Figure 8 It is a structural schematic diagram of the suction cup mechanism in the present invention.

[0054] Figure 9 Schematic diagram of the structure of the clamp unit in the present invention.

[0055] Figure 10 It is a structural schematic diagram of the first alignment mechanism in the present invention.

[0056] Figure 11 This is an exploded view of the first alignment mechanism in the present invention.

[0057] Figure 12 A schematic diagram of the structure of the second alignment mechanism in the present invention

[0058] Figure 13 This is a schematic diagram of the structure of the positioning tool in the present invention

[0059] Figure 14 Schematic diagram of the structure of the support mechanism in the present invention

[0060] Figure 15 Schematic diagram of the structure of the workpiece in the present invention

[0061] Among them: 1. Gripper quick-change mechanism; 2. Gripper frame; 3. Vision camera mechanism; 4. Fixed plate assembly; 5. Pressing finger mechanism; 6. Suction cup mechanism; 7. Clamp base; 8. First alignment mechanism; 9. Second alignment mechanism; 10. Positioning fixture; 11. Support mechanism; 12. Workpiece; 13. Gripper pin sleeve; 14. Gripper locking pin

[0062] 101. Quick-change mounting plate; 102. Quick-change mounting surface; 103. Quick-change positioning pin; 104. Quick-change locking device;

[0063] 301, camera mounting plate; 302, visual camera; 303, first quick lock; 304, protective cover; 305, first fixing pin hole; 306, second fixing pin hole;

[0064] 501, finger pressure mounting base; 502, finger pressure cylinder; 503, universal ball screw; 504, finger pressure air pipe connector; 505, second quick lock;

[0065] 601, suction cup mounting base; 602, suction cup; 603, spring rod; 604, suction cup air pipe connector; 605, rotary plunger;

[0066] 801, first mounting base; 802, first switch magnetic base; 803, light source; 804, connecting base; 805, telescopic cylinder; 806, electromagnet; 807, seat plate; 808, limit plate; 809, light-transmitting gap; 810, V-shaped groove; 811, positioning surface;

[0067] 901, pneumatic magnetic chuck; 902, chuck mounting plate; 903, first drive device; 904, second drive device; 905, rotating device;

[0068] 1001, positioning plate; 1002, mounting bracket; 1003, positioning angle;

[0069] 1101. Second mounting base; 1102. Second switch magnetic base; 1103. Support column; 1104. Nylon plate. DETAILED DESCRIPTION

[0070] The specific embodiments of the present invention will be described below with reference to the accompanying drawings.

[0071] The structure and function of the present invention are as follows:

[0072] like Figures 1-15 As shown, the alignment clamping tooling for automatic welding of automobile door rings in this embodiment includes a gripper unit and a fixture unit, and the gripper unit is connected to the working end of the robotic arm; the gripper unit includes a gripper frame 2, and the bottom of the gripper frame 2 is respectively installed with several visual camera mechanisms 3 and several suction cup mechanisms 6, the gripper unit takes pictures of the weld on the workpiece 12 through the visual camera mechanism 3, and the gripper unit sucks up the workpiece 12 through the suction cup mechanism 6, thereby transporting the workpiece 12 to the target working position of the fixture unit through the robotic arm; the fixture unit includes a fixture base 7, and the top of the fixture base 7 is installed with several first alignment mechanisms 8, the first alignment mechanism 8 is used to clamp the workpiece 12, and a light source 803 is provided in a single first alignment mechanism 8, and the light source 803 is arranged below the workpiece 12, and the light source 803 illuminates the workpiece 12 from the back of the workpiece 12, so that the visual camera mechanism 3 locates the weld on the workpiece 12.

[0073] The alignment clamping tooling for automatic tailor-welding of automobile door rings of this embodiment includes a gripper unit and a fixture unit. The gripper unit includes a gripper quick-change mechanism 1, a gripper frame 2, a visual camera mechanism 3, a fixed plate assembly 4, a finger pressing mechanism 5, and a suction cup mechanism 6. The fixture unit includes a fixture base 7, a first alignment mechanism 8, a second alignment mechanism 9, a positioning tooling 10, and a support mechanism 11.

[0074] like Figure 1-Figure 2 、 Figure 4 As shown, the gripper frame 2 is the mounting frame of the entire gripper unit, which is installed in conjunction with the visual camera mechanism 3, the finger pressing mechanism 5, and the suction cup mechanism 6 through the fixing plate group 4; in addition, several gripper pin sleeves 13 and several gripper locking pins 14 are also provided on the top of the gripper unit 1, and the gripper pin sleeves 13 and the gripper locking pins 14 are used to cooperate with the gripper quick change mechanism 1 for installation.

[0075] like Figure 15 As shown, in this embodiment, the workpiece 12 is a car door knocker of different types, which is spliced together by multiple steel plates.

[0076] The gripper unit is installed in conjunction with the working end of the robot arm through the gripper quick change mechanism 1. Figure 2-Figure 3 As shown, the structure of the gripper quick-change mechanism 1 is: it includes a quick-change mounting plate 101, the top end face of the quick-change mounting plate 101 is provided with a flat quick-change mounting surface 102, and the gripper quick-change mechanism 1 is connected to the working end of the robot arm through the quick-change mounting surface 102; the bottom of the quick-change mounting plate 101 is cooperated with and installed with several quick-change lockers 104 and several quick-change positioning pins 103, and the gripper quick-change mechanism 1 is locked and connected to the gripper frame 2 through the quick-change locker 104. The gripper quick-change mechanism 1 realizes a reliable connection between the gripper unit and the working end of the robotic arm through the quick-change mounting surface 102; in the gripper quick-change mechanism 1, the quick-change locker 104 corresponds one-to-one with the gripper locking pin 14 on the gripper frame 2, the quick-change positioning pin 103 corresponds one-to-one with the gripper pin sleeve 13, and the quick-change locker 104 is connected to the corresponding gripper locking pin 14 through an electrical control switch, thereby realizing a quick-release connection between the robotic arm and the gripper frame 2; the quick-change positioning pin 103 and the gripper pin sleeve 13 cooperate closely, which can prevent the gripper frame 2 from shifting and moving during the movement of the gripper unit driven by the robotic arm, and can ensure a reliable connection between the gripper unit and the robotic arm after repeated replacement. By setting up the gripper quick-change mechanism 1, it is convenient to quickly replace the entire gripper unit on the robotic arm when targeting door rings of different versions, thereby improving replacement efficiency.

[0077] In this embodiment, the robotic arm is used to drive the gripper unit to move, including but not limited to a multi-axis joint robot and a truss robot.

[0078] like Figure 1-Figure 2 、 Figure 4-Figure 5As shown, a fixing plate group 4 is fixed to the bottom of the gripper frame 2. The fixing plate group 4 includes several first fixing plates and several second fixing plates. Each first fixing plate and second fixing plate is equipped with at least one suction cup mechanism 6. For each first fixing plate, at least one visual camera mechanism 3 and a finger pressing mechanism 5 arranged in a one-to-one correspondence with the visual camera mechanism 3 are also equipped. That is, as Figure 4 As shown, the visual camera mechanism 3 is installed in cooperation with the gripper frame 2 through the first fixed plate 401, the finger pressing mechanism 2 is installed in cooperation with the gripper frame 2 through the first fixed plate 401, and the suction cup mechanism 6 is installed in cooperation with the first fixed plate 401 and the second fixed plate 402.

[0079] The arrangement position of the first fixing plate 401 on the gripper frame 2 is determined according to the position of the weld on the workpiece 12 , and the arrangement position of the second fixing plate 402 on the gripper frame 2 is determined according to the overall shape of the workpiece 12 .

[0080] In addition, in order to facilitate the installation of the visual camera mechanism 3 , a plurality of camera fixing pins are provided on the first fixing plate 401 .

[0081] like Figure 6 As shown, the structure of a single visual camera mechanism 3 is as follows: it includes a camera mounting plate 301, a visual camera 302 is fixed on the camera mounting plate 301, and several first quick locks 303 are arranged on the camera mounting plate 301 around the visual camera 302. The visual camera mechanism 3 is quickly connected to the first fixing plate through the first quick locks 303, and a first fixing pin hole 305 and a second fixing pin hole 306 are respectively provided on the end surface of the camera mounting plate 301. The visual camera mechanism 3 is positioned at the installation position on the first fixing plate through the first fixing pin hole 305 and the second fixing pin hole 306. The visual camera 302 is fixed to the camera mounting plate 301 by screws. In this embodiment, the pixel of the visual camera 302 is not less than 20 million. The outside of the visual camera 302 is also equipped with a protective cover 304 made of silicone material to protect the visual camera 302; the first quick lock 303 is manual, and by manually pressing the button on the upper end of the first quick lock 303, the visual camera mechanism 3 can be quickly disassembled and assembled as a whole from the first fixing plate 401; in this embodiment, the first fixing pin hole 305 is a circular hole, and the second fixing pin hole 306 is an elliptical hole. The first fixing pin hole 305 and the second fixing pin hole 306 respectively correspond to the two camera fixing pins on the first fixing plate 401, and can repeatedly and accurately position the visual camera mechanism 3, thereby improving the subsequent welding accuracy.

[0082] A finger-pressing mechanism 5 is installed next to each visual camera mechanism 3. The distribution principle of the finger-pressing mechanism 5 and the corresponding visual camera mechanism 3 is the head and tail end points of the corresponding weld on the workpiece 12, that is, each weld on the workpiece 12 is equipped with two visual camera mechanisms 3 and two finger-pressing mechanisms 5.

[0083] The finger pressing mechanism 5 is used to press against the workpiece 12 to prevent the corners of the workpiece 12 from tilting up when the visual camera 302 takes pictures, thereby affecting the picture taking results and ensuring the accuracy of the pictures.

[0084] like Figure 7 As shown, the structure of a single finger-pressing mechanism 5 is: it includes a finger-pressing mounting seat 501, on which several second quick locks 505 are fixed, and the finger-pressing mechanism 5 is quickly connected to the first fixed plate through the second quick locks 505, and several finger-pressing cylinders 502 are fixed at the bottom of the finger-pressing mounting seat 501, and the output end of a single finger-pressing cylinder 502 is connected to the universal ball screw 503; the finger-pressing cylinder 502 drives the corresponding universal ball screw 503 to extend, so that the universal ball of the corresponding universal ball screw 503 presses against the workpiece 12. In this embodiment, the finger-pressing cylinder 502 adopts a single-acting cylinder, which is used to drive the universal ball screw 503 to move linearly. The top of the finger-pressing mounting seat 501 is equipped with a finger-pressing air pipe connector 504, which is used to supply air to the finger-pressing cylinder 502; the working end of the universal ball screw 503 is provided with a universal ball, and the universal ball screw 503 contacts the workpiece 12 through the universal ball, which can reduce the movement resistance of the workpiece 12 during the subsequent weld alignment process; the second quick locker 505 is also manual, which is used for the quick disassembly and assembly of the finger-pressing mechanism 5 from the first fixed plate 401.

[0085] The suction cup mechanism 6 is used to absorb the workpiece 12, such as Figure 8 As shown, the structure of a single suction cup mechanism 6 is as follows: it includes a suction cup mounting base 601, which is mounted in conjunction with the fixed plate assembly 4 via a rotating plunger 605. The bottom of the suction cup mounting base 601 is mounted with a suction cup 602 via a spring rod 603. The top of the suction cup mounting base 601 is mounted with a suction cup air pipe connector 604 for connecting to an external air source. The external air source drives the suction cup 602 through the suction cup air pipe connector 604 to suck up the workpiece 12. The spring rod 603 acts as a buffer when the suction cup 602 contacts the workpiece 12; the rotating plunger 605 is used to cooperate with the fixed plate assembly 4, enabling rapid disassembly and assembly between the suction cup mechanism 6 and the fixed plate assembly 4; and the suction cup air pipe connector 604 is used to supply air to the suction cup 602.

[0086] In this embodiment, each gripper unit is designed for a door ring of a specific type. When the clamping tooling is used to process door rings of different types, the gripper unit (including the gripper frame 2, the visual camera mechanism 3, the fixed plate group 4, the finger pressing mechanism 5, and the suction cup mechanism 6) at the working end of the robot arm is quickly replaced through the gripper quick-change unit 1 to match the door ring type and improve the welding accuracy.

[0087] like Figure 9 As shown, the clamp base 7 is the mounting carrier of the entire gripper unit, which is fixed on the bracket or cooperates with the movable slide; the first alignment mechanism 8, the second alignment mechanism 9, the positioning tooling 10, and the support mechanism 11 are all installed on the top of the clamp base 7.

[0088] like Figure 10-11 As shown, the structure of a single first alignment mechanism 8 is as follows: it includes a first mounting base 801, on which at least one first switch magnetic base 802 is fixed, the first alignment mechanism 8 is quickly connected to the fixture base 7 through the first switch magnetic base 802, a connecting base 804 is fixed on the top of the first mounting base 801, a telescopic cylinder 805 is fixed on the connecting base 804, the output end of the telescopic cylinder 805 is connected to the light source 803, a seat plate 807 is fixed on the top of the connecting base 804, a strip-shaped through hole is opened on the end face of the seat plate 807, and a plurality of electromagnets 806 are installed at intervals on the top of the seat plate 807, and a light-transmitting gap 809 is formed between two adjacent electromagnets 806, and the light-transmitting gap 809 is arranged corresponding to the strip-shaped through hole; the telescopic cylinder 805 drives the light source 803 to move linearly, so that the light source 803 illuminates the workpiece 12 from the back of the workpiece 12 through the light-transmitting gap 809. The first alignment mechanism 8 is used to support the workpiece 12 and perform polishing during weld alignment. In addition, after weld alignment is completed, the workpiece 12 can be attracted and fixed by the electromagnet 806.

[0089] The first alignment mechanism 8 is used to achieve quick disassembly and assembly with the clamp base 7 through the first switch magnetic seat 802; the first switch magnetic seat 802 is a manual knob type. When the first alignment mechanism 8 is working normally, the first switch magnetic seat 802 is adsorbed and fixed on the top of the clamp base 7; when the door knocker version is changed, the position of the first alignment mechanism 8 needs to be moved. At this time, the knob on the first switch magnetic seat 802 is manually rotated to demagnetize it. After moving to the new position, the button is manually rotated again to make it adsorbed on the clamp base 7;

[0090] Electromagnets 806 are fixed to a base plate 807. Two electromagnets 806 are spaced apart, forming a light-transmitting gap 809 between them. The width of light-transmitting gap 809 is 10 mm to 16 mm. The two electromagnets 806 are connected and limited by a limit plate 808. A V-shaped groove 810 is formed on the top of the limit plate 808. The V-shaped groove 810 positions the two electromagnets 806, thereby ensuring the width of the light-transmitting gap 809.

[0091] Two adjacent outer side walls of one electromagnet 806 form a positioning surface 811, and the positioning surface 811 corresponds to the positioning angle 1003 in the positioning fixture 10, so that the installation position of the first alignment mechanism 8 on the fixture base 7 can be determined by the positioning fixture 10;

[0092] The two electromagnets 806 in the first alignment mechanism 8 respectively absorb or support the welding edges of the two steel plates in the workpiece 12, and make the joint weld of the two steel plates fall between the light-transmitting gap 809;

[0093] The light source 803 is driven to move to the light-transmitting gap 809 by the telescopic cylinder 805, thereby lighting from below the workpiece 12; when lighting is not needed, the telescopic cylinder 805 is retracted, so that the light source 803 is moved away from the light-transmitting gap 809, thereby preventing welding slag from splashing from the light-transmitting gap 809 and damaging the light source 803 during subsequent welding;

[0094] The light source 803 is in the shape of a long strip and is used to illuminate the workpiece 12 from bottom to top. At this time, to the visual camera 302, the background and the weld are bright and the workpiece 12 is dark, which can improve the camera capture accuracy and thus improve the weld alignment accuracy.

[0095] In this embodiment, the top of the fixture base 7 is also equipped with several second alignment mechanisms 9, which are used to fine-tune the position of each steel plate in the workpiece 12 to align the weld seam; Figure 12 As shown, a single second alignment mechanism 9 includes a first drive device 903, a working end of the first drive device 903 is connected to a second drive device 904, a working end of the second drive device 904 is connected to a rotating device 905, a working end of the rotating device 905 is connected to a suction cup mounting plate 902, and a plurality of pneumatic magnetic suction cups 901 are fixed on the top of the suction cup mounting plate 902; the pneumatic magnetic suction cups 901 are used to absorb the end surface of the corresponding steel plate in the workpiece 12, and are driven by the first drive device 903 to perform linear motion along the horizontal X direction, driven by the second drive device 904 to perform linear motion along the horizontal Y direction, and driven by the rotating device 905 to perform rotational motion along the circumferential direction, thereby adjusting the position of the steel plate;

[0096] In the second alignment mechanism 9, the first drive device 903 and the second drive device 904 both adopt a structure in which a drive member cooperates with a slider and a slide rail. The drive member can be a cylinder or a motor. When the drive member adopts a rotary motor, a screw feed mechanism can be equipped for transmission.

[0097] The rotating device 905 adopts a structure in which a motor is matched with a slewing bearing.

[0098] A positioning tool 10 is fixed on the top of the fixture base 7. Figure 13 As shown, the positioning fixture 10 is used to determine the layout position of the first alignment mechanism 8. The positioning fixture 10 includes a mounting bracket 1002, a positioning plate 1001 is fixed to the top of the mounting bracket 1002, and the edge of the positioning plate 1001 is provided with a plurality of spaced positioning angles 1003, and the positioning angles 1003 correspond one-to-one with the first alignment mechanism 8. Because the light-transmitting gaps 809 in the first alignment mechanism 8 need to correspond one-to-one with the welds on the workpiece 12, different shapes of positioning plates 1001 are used for different door ring types, thereby flexibly adjusting the layout position of the first alignment mechanism 8 on the fixture base 7.

[0099] The top of the fixture base 7 is also equipped with several supporting mechanisms 11 for supporting the workpiece 12, such as Figure 14 As shown, the structure of a single support mechanism 11 is as follows: it includes a second mounting base 1101, at least one second switch magnetic base 1102 fixed to the bottom of the second mounting base 1101, and the support mechanism 11 is quickly connected to the fixture base 7 via the second switch magnetic base 1102. Several support columns 1103 are fixed to the top of the second mounting base 1101, and nylon plates 1104 are also installed on the top of the support columns 1103. The support mechanism 11 is used to provide auxiliary support for the workpiece 12 to prevent the steel plate in the workpiece 12 from overturning. Similarly, the support mechanism 11 is quickly disassembled and assembled with the fixture base 7 via the second switch magnetic base 1102, so that the installation position of the support mechanism 11 on the fixture base 7 can be quickly and flexibly moved to match different door knocker styles.

[0100] A weld alignment method based on the above-mentioned alignment clamping tool for automatic tailor-welding of automobile door rings comprises the following steps:

[0101] Step 1: Preparation: Use a robot to place the steel plates in the workpiece 12 in place. In this embodiment, the robot places the steel plates into a door ring structure with a placement accuracy of 2 mm.

[0102] Step 2: The robot arm drives the gripper unit to move to the top of the workpiece 12 placed in place. The gripper unit sucks the workpiece 12 placed in place through the suction cup mechanism 6, and then the robot arm transfers the workpiece 12 through the gripper unit;

[0103] When each weld seam on the workpiece 12 corresponds to each light-transmitting gap 809 in the first alignment mechanism 8, it indicates that the robot arm has transferred the workpiece 12 to the target working position of the fixture unit, and then the suction cup mechanism 6 releases the workpiece 12;

[0104] Step 3: The gripper unit is lifted to a certain height by the robotic arm, so that the distance between the lens of the visual camera 302 in the visual camera mechanism 3 and the upper surface of the workpiece 12 is equal to the focal length of the visual camera 302. Subsequently, the finger-pressing cylinders 502 in the finger-pressing mechanism 5 are extended simultaneously, driving the corresponding universal ball screws 503 to press against the upper surface of the workpiece 12.

[0105] Step 4: The telescopic cylinders 805 in each first alignment mechanism 8 are extended simultaneously, driving the corresponding light source 803 to move to face the light-transmitting gap 809, so that the light source 803 illuminates the corresponding weld;

[0106] Step 5: Use the visual camera 302 to take photos of the two ends of each weld and transmit the photo data to the industrial computer. The industrial computer calculates the gap of each weld based on the photo data and calculates the difference between the gaps of different welds.

[0107] Based on the gaps of each weld, the differences between the gaps of different welds, and the welding requirements, the industrial computer calculates the target positions of each steel plate in the workpiece 12;

[0108] Step 6: The second alignment mechanism 9 adjusts each steel plate in the workpiece 12 to the target position. Subsequently, the visual camera 302 takes photos of the positions at both ends of each weld seam. The industrial computer determines whether the alignment of each weld seam in the workpiece 12 is completed based on the photo data taken by the visual camera 302.

[0109] When the alignment of each weld seam in the workpiece 12 is completed, each finger pressing mechanism 5 releases the workpiece 12, and the light source 803 in each first alignment mechanism 8 retracts to the initial position;

[0110] When the alignment of the weld seams in the workpiece 12 is not completed, the fifth and sixth steps are repeated until the alignment of the weld seams in the workpiece 12 is completed.

[0111] The following is a specific embodiment:

[0112] In this embodiment, Figure 15 As shown, the workpiece 12 adopts a five-seam door ring, and the workpiece 12 includes steel plate A, steel plate B, steel plate C, steel plate D, and steel plate E, five steel plates, and five welds;

[0113] Arrange 10 visual camera mechanisms 3, 10 finger pressing mechanisms 5, no less than 15 suction cup mechanisms 6, 5 first alignment mechanisms 8, and 5 second alignment mechanisms 9; among them, the 10 visual camera mechanisms 3 correspond to Figure 15 The symbols ①-⑩ in the figure;

[0114] When performing weld alignment, visual camera mechanism ①-visual camera mechanism 10 respectively photographs the four corners of the welding edge of steel plate A-steel plate E, wherein visual camera mechanism ①, visual camera mechanism ②, visual camera mechanism ③, and visual camera mechanism ④ locate the four corners of steel plate A; visual camera mechanism ③, visual camera mechanism ④, visual camera mechanism ⑤, and visual camera mechanism ⑥ locate the four corners of steel plate B; visual camera mechanism ⑤, visual camera mechanism ⑥, visual camera mechanism ⑦, and visual camera mechanism ⑧ locate the four corners of steel plate C; visual camera mechanism ⑦, visual camera mechanism ⑧, visual camera mechanism ⑨, and visual camera mechanism 10 locate the four corners of steel plate D; visual camera mechanism ⑨, visual camera mechanism 10, visual camera mechanism ①, and visual camera mechanism ② locate the four corners of steel plate E;

[0115] Vision camera mechanism ① and vision camera mechanism ② correspond to the weld between steel plate A and steel plate E, vision camera mechanism ③ and vision camera mechanism ④ correspond to the weld between steel plate A and steel plate B, vision camera mechanism ⑤ and vision camera mechanism ⑥ correspond to the weld between steel plate B and steel plate C, vision camera mechanism ⑦ and vision camera mechanism ⑧ correspond to the weld between steel plate C and steel plate D, and vision camera mechanism ⑨ and vision camera mechanism ⑩ correspond to the weld between steel plate D and steel plate E;

[0116] After steel plates A-E are placed on the fixture unit, visual camera mechanisms ①-⑩ take photos of the corresponding weld end points. The industrial computer measures the gap of each weld and the difference between the gaps of different welds, thereby simulating and calculating the target position of steel plates A-E under welding conditions.

[0117] The second alignment mechanism 9 adjusts the corresponding steel plates and continuously feeds back the position information of steel plates A-E to the industrial computer through the visual camera mechanism ①-visual camera mechanism ⑩, thereby adjusting steel plates A-E to the target positions respectively;

[0118] Then, the visual camera mechanism ①-visual camera mechanism ⑩ is used to confirm whether each weld meets the tolerance requirements in the welding requirements. In this embodiment, the tolerance requirements are within ±0.05mm. If the tolerance requirements are met, the weld alignment is completed; if not, the position of the corresponding steel plate is fine-tuned again through the second alignment mechanism 9, and the visual camera mechanism ①-visual camera mechanism ⑩ continuously feeds back the position information of the industrial computer steel plate A-steel plate E until each weld meets the tolerance requirements.

[0119] The present invention can be applied to the welding of skylights or single and double door rings with 3 to 10 seams, and can realize flexible and automatic splicing of welds.

[0120] The above description is an explanation of the present invention, not a limitation of the present invention. The scope of the present invention is defined in the claims. Any modifications may be made within the scope of protection of the present invention.

Claims

1. A positioning clamping tool for automatic welding of automobile door rings, characterized by: It includes a gripper unit and a clamp unit, wherein the gripper unit is connected to the working end of the robot arm; The gripper unit comprises a gripper frame (2), and the bottom of the gripper frame (2) is respectively equipped with a plurality of visual camera mechanisms (3) and a plurality of suction cup mechanisms (6). The gripper unit takes a picture of the weld on the workpiece (12) through the visual camera mechanism (3), and the gripper unit sucks up the workpiece (12) through the suction cup mechanism (6), thereby transporting the workpiece (12) to the target working position of the gripper unit through the robot arm; The fixture unit includes a fixture base (7), a plurality of first alignment mechanisms (8) are mounted on the top of the fixture base (7), the first alignment mechanisms (8) are used to clamp the workpiece (12), a light source (803) is provided in a single first alignment mechanism (8), the light source (803) is arranged below the workpiece (12), and the light source (803) illuminates the workpiece (12) from the back side of the workpiece (12), thereby enabling the visual camera mechanism (3) to locate the weld on the workpiece (12); The structure of a single first alignment mechanism (8) is as follows: it includes a first mounting base (801), at least one first switch magnetic base (802) is fixed on the first mounting base (801), the first alignment mechanism (8) is quickly disassembled and connected to the clamp base (7) through the first switch magnetic base (802), a connecting base (804) is fixed on the top of the first mounting base (801), a telescopic cylinder (805) is fixed on the connecting base (804), the output end of the telescopic cylinder (805) is connected to the light source (803), a seat plate (807) is fixed on the top of the connecting base (804), a strip-shaped through hole is opened on the end surface of the seat plate (807), a plurality of electromagnets (806) are installed at intervals on the top of the seat plate (807), a light-transmitting gap (809) is formed between two adjacent electromagnets (806), and the light-transmitting gap (809) is arranged corresponding to the strip-shaped through hole; The telescopic cylinder (805) drives the light source (803) to move linearly, thereby allowing the light source (803) to illuminate the workpiece (12) from the back side of the workpiece (12) through the light-transmitting gap (809).

2. The alignment clamping tool for automatic tailor welding of automobile door rings according to claim 1, characterized in that: A fixing plate group (4) is fixed to the bottom of the gripper frame (2), and the fixing plate group (4) includes a plurality of first fixing plates and a plurality of second fixing plates, and each of the first fixing plates and the second fixing plates is cooperatively mounted with at least one suction cup mechanism (6); The single first fixed plate is also cooperatively mounted with at least one visual camera mechanism (3) and a finger pressing mechanism (5) arranged in a one-to-one correspondence with the visual camera mechanism (3).

3. The positioning clamping tool for automatic tailor welding of automobile door rings according to claim 2, characterized in that: The structure of a single visual camera mechanism (3) is as follows: it includes a camera mounting plate (301), a visual camera (302) is fixed on the camera mounting plate (301), a plurality of first quick locks (303) are arranged on the camera mounting plate (301) around the visual camera (302), the visual camera mechanism (3) is quickly connected to the first fixing plate through the first quick locks (303), a first fixing pin hole (305) and a second fixing pin hole (306) are respectively opened on the end surface of the camera mounting plate (301), and the visual camera mechanism (3) is positioned at an installation position on the first fixing plate through the first fixing pin hole (305) and the second fixing pin hole (306).

4. The alignment clamping tool for automatic tailor welding of automobile door rings according to claim 3, characterized in that: The structure of a single finger pressing mechanism (5) is as follows: it includes a finger pressing mounting seat (501), a plurality of second quick lockers (505) are fixed on the finger pressing mounting seat (501), the finger pressing mechanism (5) is quickly connected to the first fixing plate via the second quick lockers (505), a plurality of finger pressing cylinders (502) are fixed at the bottom of the finger pressing mounting seat (501), and the output end of a single finger pressing cylinder (502) is connected to a universal ball screw (503); The finger-pressing cylinder (502) drives the corresponding universal ball screw (503) to extend, thereby causing the universal ball of the corresponding universal ball screw (503) to press against the workpiece (12).

5. The alignment clamping tool for automatic tailor welding of automobile door rings according to claim 4, characterized in that: The structure of a single suction cup mechanism (6) is as follows: it comprises a suction cup mounting seat (601), the suction cup mounting seat (601) is mounted in cooperation with the fixed plate group (4) via a rotating plunger (605), a suction cup (602) is mounted in cooperation with the bottom of the suction cup mounting seat (601) via a spring rod (603), and a suction cup air pipe connector (604) for connecting to an external air source is mounted in cooperation with the top of the suction cup mounting seat (601), and the external air source drives the suction cup (602) via the suction cup air pipe connector (604) to suck up the workpiece (12).

6. The alignment clamping tool for automatic tailor welding of automobile door rings according to claim 5, characterized in that: The gripper unit is mounted in cooperation with the working end of the robotic arm via a gripper quick-change mechanism (1), the gripper quick-change mechanism (1) comprising a quick-change mounting plate (101), the top end surface of the quick-change mounting plate (101) being provided with a planar quick-change mounting surface (102), and the gripper quick-change mechanism (1) is connected in cooperation with the working end of the robotic arm via the quick-change mounting surface (102); The bottom of the quick-change mounting plate (101) is cooperatively mounted with a plurality of quick-change lockers (104) and a plurality of quick-change positioning pins (103). The gripper quick-change mechanism (1) is locked and connected to the gripper frame (2) via the quick-change lockers (104).

7. The alignment clamping tool for automatic tailor welding of automobile door rings according to claim 6, characterized in that: A positioning tool (10) is fixed on the top of the clamp base (7), and the positioning tool (10) is used to locate the layout position of the first alignment mechanism (8). The positioning tool (10) includes a mounting bracket (1002), and a positioning plate (1001) is fixed on the top of the mounting bracket (1002). The edge of the positioning plate (1001) is provided with a plurality of positioning angles (1003) arranged at intervals, and the positioning angles (1003) correspond one-to-one to the first alignment mechanism (8).

8. The alignment clamping tool for automatic tailor welding of automobile door rings according to claim 7, characterized in that: The top of the clamp base (7) is also equipped with several support mechanisms (11) for supporting the workpiece (12). The structure of a single support mechanism (11) is as follows: it includes a second mounting base (1101), at least one second switch magnetic base (1102) is fixed to the bottom of the second mounting base (1101), the support mechanism (11) is quickly connected to the clamp base (7) through the second switch magnetic base (1102), and several support columns (1103) are fixed to the top of the second mounting base (1101), and a nylon plate (1104) is also installed on the top of the support column (1103).

9. A weld alignment method based on the alignment clamping tool for automatic tailor welding of automobile door rings according to claim 8, characterized in that: The steps include: Step 1: Preparation: Using a robot to pre-place the various steel plates in the workpiece (12); Step 2: The gripper unit is driven by the robotic arm to move to the top of the workpiece (12) that is in place, the gripper unit sucks the workpiece (12) that is in place through the suction cup mechanism (6), and then the robotic arm transfers the workpiece (12) through the gripper unit; When each weld seam on the workpiece (12) corresponds to the light-transmitting gap (809) in each first alignment mechanism (8), it indicates that the robot arm transfers the workpiece (12) to the target working position of the fixture unit, and then the suction cup mechanism (6) releases the workpiece (12); Step 3: The gripper unit is lifted to a certain height by the robotic arm, so that the distance between the lens of the visual camera (302) in the visual camera mechanism (3) and the upper surface of the workpiece (12) is equal to the focal length of the visual camera (302), and then each finger-pressing cylinder (502) in the finger-pressing mechanism (5) is extended at the same time to drive the corresponding universal ball screw (503) to press against the upper surface of the workpiece (12); Step 4: The telescopic cylinders (805) in each first alignment mechanism (8) are extended simultaneously, driving the corresponding light source (803) to move to face the light-transmitting gap (809), so that the light source (803) illuminates the corresponding weld; Step 5: Using a visual camera (302), take photos of the two ends of each weld, and transmit the photo data to an industrial computer. The industrial computer calculates the gap of each weld based on the photo data, and calculates the difference between the gaps of different welds. According to the gaps of each weld, the difference between the gaps of different welds, and the welding requirements, the industrial computer calculates the target position of each steel plate in the workpiece (12); Step 6: Adjust each steel plate in the workpiece (12) to the target position by the second alignment mechanism (9), and then take photos of the positions at both ends of each weld again by the visual camera (302). The industrial computer determines whether the alignment of each weld in the workpiece (12) is completed based on the photo data taken again by the visual camera (302); When the alignment of each weld seam in the workpiece (12) is completed, each finger pressing mechanism (5) releases the workpiece (12), and the light source (803) in each first alignment mechanism (8) retracts to an initial position; When the alignment of the weld seams in the workpiece (12) is not completed, the fifth and sixth steps are repeated until the alignment of the weld seams in the workpiece (12) is completed.

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