A three-wheel edging tool and an edging method thereof

Abstract

The application discloses a three-wheel rolling tool and a rolling method thereof, and relates to the field of automobile production and manufacturing. The three-wheel rolling tool comprises a first roller, a second roller and a third roller which are sequentially installed along a rolling path and are rotationally installed in an increasing angle between a working surface and a horizontal plane, a first roller mechanism for driving the first roller to vertically ascend or descend, and a third roller mechanism for driving the third roller to revolve around a vertical revolving rotation shaft which deviates from an axis of the third roller. The second roller is rotationally installed at a bottom end of an equipment mounting base. The three-wheel rolling tool integrates two pre-rolling processes and one final rolling process of a flanging process, and one-time realization of the three-wheel rolling tool not only simplifies a rolling process flow and improves a production rhythm, but also eliminates positioning errors caused by robot part grabbing and clamp switching among different processes in a one-time clamping production mode, is beneficial to improvement of product quality, and can meet the processing requirements of various radian edge contour shape body-in-white of non-small chord length types.

Description

Technical Field

[0001] This invention relates to the field of automobile manufacturing technology, and specifically to a hemming tool and hemming method for automobile body-in-white. Background Technology

[0002] A hemming tool is a device used to form the edge structure of an automotive body-in-white. In existing technologies, the hemming process includes pre-hemming and final hemming, with each hemming step involving rollers and related structures operating independently, sequentially completing the hemming process. This inevitably leads to numerous processing steps, long production cycles, and low production efficiency. Structurally, hemming tools rely on cushioning structures such as cylinders, airbags, and springs to ensure flexible contact between the rollers and the sheet metal for pre-hemming or final hemming. However, this structure limits the height of the rollers' flexibility, potentially requiring the robot to switch between different fixtures and frequently reposition itself between different processes, which can negatively impact product quality. Furthermore, fixture switching and repositioning further complicate the hemming process, extending the production cycle and reducing efficiency. In addition, existing technologies require a large number of robots and fixtures for the hemming process, resulting in high equipment costs and large space requirements.

[0003] Based on existing technology searches, the following known technical solutions exist: Prior art 1: Application number: CN201922482417.7, application date: 2019.12.31, publication (announcement) date: 2020.09.25.

[0004] Prior art 1 discloses a rolling mechanism for automotive sidewall wheel covers, including a sidewall assembly platform, a tire film assembly, a rolling head assembly, and a connecting assembly. The sidewall assembly platform includes a base plate, the tire film assembly includes a tire film and a wheel cover clamp for clamping the sidewall wheel cover, the tire film is fixed on the base plate, the wheel cover clamp is mounted on the tire film, the rolling head assembly includes rollers, one end of the connecting assembly is used to connect to a robot, and the other end of the connecting assembly is connected to the rolling head assembly. In the technical solution of this utility model, the rolling of the sidewall wheel cover and the welding of the sidewall assembly can be completed in one station, eliminating the need for a separate station for the tire film. For different vehicle models, the tire film and the sidewall assembly platform can be switched simultaneously, speeding up the production cycle.

[0005] Prior art 2: Application number: CN202120308515.3, application date: 2021.02.03, publication (announcement) date: 2021.11.30.

[0006] Prior art 2 relates to a robotic hemming tool, including a roller assembly and a hemming guide support mechanism for providing support and elasticity to the roller assembly. The roller assembly includes a roller seat and a hemming wheel disposed on the roller seat. The hemming guide support mechanism includes a sleeve, a hemming shaft disposed within the sleeve and movable along the sleeve's axial direction, and an elastic preload structure disposed between the hemming shaft and a hemming seat at the top of the sleeve. The elastic preload structure includes a guide shaft and a spring. The guide shaft is threadedly connected to the hemming shaft, and the spring is disposed between the ends of the hemming shaft and the guide shaft. The roller seat is connected to the lower end of the hemming shaft. This invention has a simple and compact structure, small size, and provides ample operating space for the robot to adjust its posture. The preload structure can adjust and control the initial pressure of the spring, ensuring the hemming pressure of the hemming tool during hemming, thereby ensuring the hemming quality and effect of the stamped parts.

[0007] The above search results show that the above technical solutions do not affect the novelty of the present invention; and the combination of the above prior art does not destroy the inventiveness of the present invention. Summary of the Invention

[0008] To avoid the shortcomings of the prior art, the present invention provides a three-wheeled hemming tool and a hemming method thereof.

[0009] The present invention adopts the following technical solution to solve the technical problem: a three-wheeled edge rolling tool for forming tire film edge rolling, including an equipment mounting base as the frame of the edge rolling tool, wherein the equipment mounting base is mounted and connected to a robot via a robot connecting base provided at its top. It also includes a first roller mechanism, a third roller mechanism, a first roller, a second roller, and a third roller; When the equipment mounting base is in a standing position, the first roller, the second roller, and the third roller are arranged sequentially along the rolling edge path, and the angle between the working surfaces of the three rollers and the horizontal plane increases progressively; the angle between the rotation axis of the first roller and the projection of the tangent of the fetal membrane onto the horizontal plane does not exceed 15°. The first roller is rotatably connected to the output end of the first roller mechanism that is fixed to the device mounting base, and a rotating pair that supports the first roller to rotate around its own axis is formed between the two. The output end of the first roller mechanism outputs a motion that drives the first roller to move vertically upward or downward. The second roller is rotatably mounted to the bottom of the equipment mounting base, forming a rotating pair between them that supports the second roller to rotate around its own axis; The third roller is rotatably connected to the output end of the third roller mechanism, which is fixed to the mounting base of the equipment. The two form a rotating pair that supports the third roller to rotate around its own axis. The output end of the third roller mechanism outputs motion that drives the third roller to revolve around a vertical rotary axis that deviates from its own axis.

[0010] Furthermore, the first roller adjustment mechanism includes a first roller electric cylinder and a movable arm; The first roller electric cylinder is mounted and fixed on the equipment mounting base, and its output end is mounted and connected to the front end of the movable arm. The end of the movable arm serves as the output end of the first roller adjustment mechanism and is rotatably mounted and connected to the first roller.

[0011] Furthermore, the first roller adjustment mechanism is also equipped with a connecting block and a pressure sensor; The output end of the first roller electric cylinder is connected to the front end of the movable arm via a connecting block. The connecting block is fixed to the output end of the first roller electric cylinder and embedded in the front end of the movable arm. A pressure sensor is provided at the connection between the connecting block and the movable arm.

[0012] Furthermore, either the movable arm or the equipment mounting base is provided with a first roller slider, and the other is provided with a corresponding first roller slide rail. The first roller slider and the first roller slide rail are slidably connected, so that a linear sliding pair supporting the vertical relative sliding of the movable arm and the equipment mounting base is formed.

[0013] Furthermore, the third roller mechanism also includes a servo motor and a rotary arm; The servo motor is mounted and fixed on the equipment mounting base, and its output end is mounted and connected to the front end of the rotary arm. The end of the rotary arm serves as the output end of the third roller mechanism and is rotatably mounted and connected to the third roller.

[0014] Furthermore, the third roller mechanism also includes a coupling and a torque sensor disposed between the servo motor and the rotary arm; The output end of the servo motor is connected and fixed to the input end of the torque sensor via the coupling, and the output end of the torque sensor is connected and fixed to the front end of the rotary arm via the coupling.

[0015] Furthermore, the third roller mechanism also includes a scale; The graduated scale is located at the end of the rotary arm and is fixed to the equipment mounting base. It is used to calibrate the revolution angle of the rotary arm.

[0016] A method for using a three-wheeled hemming tool to control the hemming of an automotive body-in-white by the three-wheeled hemming tool includes the following steps: The first step is to generate offline trajectory data. Using the second roller as the reference position, and based on the digital model of the plate to be rolled, the robot offline simulation technology is used to output the offline trajectory data and node information of the second roller in the rolling method. The second step is initial node calibration. 1) The robot moves, causing the three-wheeled hemming tool, which is its end effector, to move closer to the diaphragm of the plate to be hemmed, so that the reference position coincides with the initial node of the offline trajectory. 2) The staff observes the working status of the second roller, uses the six-axis degrees of freedom of the robot to adjust the position of the second roller so that the working surface of the second roller contacts the flange of the plate to be rolled, and at the same time ensures that the working surface of the second roller completely covers the flange, and that at least 1 mm of the second roller extends out to the outside of the flange edge. At this point, when the staff manually rolls the second roller, they should feel a sliding friction between the second roller and the flange. 3) Maintain the contact state between the working surface of the second roller and the flange. Utilize the linear motion of the first roller driven by the electric cylinder of the first roller, the revolution of the third roller driven by the servo motor, and the coordinated action of the robot's six-axis degrees of freedom to adjust the overall rotation of the three-wheeled edge rolling tool around the axis of the second roller, so that the working surfaces of the first roller and the third roller completely cover the flange, with at least 1mm of the portion extending to the outside of the flange edge. At this time, when the staff manually rolls the first roller and the third roller, they should feel the sliding friction between the first roller and the third roller and the flange. 4) The program records various parameters at this time, including the spatial coordinates of the reference position, the spatial coordinates and posture of the robot, the magnitude of the force output by the first roller electric cylinder, and the magnitude of the torque output by the servo motor; 5) Use the calibrated parameters obtained in step 4 as the parameter information of the initial node, and adjust the working posture of the robot and the three-wheeled hemming tool at the initial node position according to the parameter information in repetitive production. The third step is subsequent node calibration. The robot moves the three-wheeled hemming tool to the reference position to coincide with the next node. Then, the parameters of the node after calibration are obtained according to the methods in steps 2) to 4) of the second step. These parameters are used as the parameter information of the node. In repetitive production, the working posture of the robot and the three-wheeled hemming tool at the node position is adjusted according to the parameter information until all nodes are calibrated. Step 4, Production By referring to the initial node parameter information and subsequent node parameter information in steps three and four, the work is repeated to achieve one-time rolling edge forming of workpiece flanging in batches.

[0017] Furthermore, when performing the first-time edge forming of the workpiece by the method in step four, if the difference between the magnitude of the force output by the first roller electric cylinder and the magnitude of the torque output by the servo motor obtained by real-time monitoring and the magnitude of the force output by the first roller electric cylinder and the magnitude of the torque output by the servo motor obtained in step two or three exceeds a preset allowable value, the edge forming tool will stop.

[0018] Furthermore, in the second and third steps, when the program records various parameters, the staff records the rotation angle of the slewing arm using a graduated ruler.

[0019] This invention provides a three-wheeled hemming tool and its hemming method, which has the following beneficial effects: 1. This invention integrates the two pre-rolling processes and one final rolling process of flanging into a single process using a three-wheel rolling tool. This not only simplifies the rolling process and improves the production cycle, but also eliminates the positioning errors caused by robot gripping and fixture switching between different processes, which is beneficial to improving product quality.

[0020] 2. This invention achieves flexible adjustment of the first, second, and third rollers through the six-axis degrees of freedom provided by the robot and the seventh and eighth-axis degrees of freedom provided by the first and third roller mechanisms, which can meet the processing requirements of white body with various arc edge contour shapes that are not of small chord length. 3. The equipment of this invention has a high degree of integration and occupies a small area, which is conducive to the control of production costs, including equipment costs and site costs.

[0021] 4. This invention combines economy, safety, good operability and reliability, and meets the needs of actual production. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the structure of the present invention; Figure 2 This is a schematic diagram of the main structure of the present invention; Figure 3 This is a schematic diagram of the left-side structure of the present invention; Figure 4 This is a bottom-view structural diagram of the present invention.

[0023] In the picture: 1. Equipment mounting base; 2. Robot connecting base; 3. First roller mechanism; 31. First roller electric cylinder; 32. Connecting block; 33. Movable arm; 4. Third roller mechanism; 41. Servo motor; 42. Rotary arm; 43. Scale; 5. First roller; 6. Second roller; 7. Third roller. Detailed Implementation

[0024] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0025] like Figures 1-4 As shown, this three-wheeled hemming tool is used for hemming sheet metal parts, and is particularly suitable for hemming four-door and two-cover parts of automobiles, namely the hood, trunk lid, and four doors. Its structural relationship is as follows: A three-wheeled hemming tool for forming tire film hemming includes an equipment mounting base 1 serving as the hemming tool frame. The equipment mounting base 1 is connected to a robot via a robot connecting base 2 located at its top. In actual setup, the robot can be selected as KR360-R2830; It also includes a first roller mechanism 3, a third roller mechanism 4, a first roller 5, a second roller 6, and a third roller 7; When the equipment mounting base 1 is in a standing position, the first roller 5, the second roller 6 and the third roller 7 are arranged sequentially along the rolling edge path, and the angle between the working surface of the three rollers, i.e. the contact point between the roller and the tire membrane and the horizontal plane increases progressively; the angle formed by the rotation axis of the first roller 5 and the second roller 6 and the projection of the tangent of the tire membrane onto the horizontal plane does not exceed 15°. In specific settings, the included angle is preferably no more than 5°; The first roller 5 is rotatably connected to the output end of the first roller mechanism 3, which is fixed to the equipment mounting base 1. The two form a rotating pair that supports the first roller 5 to rotate around its own axis. The output end of the first roller mechanism 3 outputs the motion of the first roller 5 to move vertically upward or downward. The second roller 6 is rotatably mounted to the bottom of the equipment mounting base 1, and a rotating pair is formed between the two to support the second roller 6 to rotate around its own axis; The third roller 7 is rotatably connected to the output end of the third roller mechanism 4, which is fixed to the equipment mounting base 1. The two form a rotating pair that supports the third roller 7 to rotate around its own axis. The output end of the third roller mechanism 4 outputs the motion that drives the third roller 7 to revolve around a vertical rotary axis that deviates from its own axis.

[0026] Preferably, the first roller adjustment mechanism 3 includes a first roller electric cylinder 31 and a movable arm 33; The first roller electric cylinder 31 is installed and fixed on the equipment mounting base 1, and its output end is installed and connected to the front end of the movable arm 33. The end of the movable arm 33 serves as the output end of the first roller adjustment mechanism 3 and is rotatably installed and connected to the first roller 5.

[0027] Preferably, the first roller adjustment mechanism 3 is further provided with a connecting block 32 and a pressure sensor; The output end of the first roller electric cylinder 31 is connected to the front end of the movable arm 33 via a connecting block 32. The connecting block 32 is fixedly installed to the output end of the first roller electric cylinder 31 and embedded in the front end of the movable arm 33. A pressure sensor is provided at the connection between the connecting block 32 and the movable arm 33. This pressure sensor is used to detect the magnitude of the force output by the first roller electric cylinder 31.

[0028] Preferably, either the movable arm 33 or the equipment mounting base 1 is provided with a first roller slider, and the other is provided with a corresponding first roller slide rail. The first roller slider and the first roller slide rail are slidably connected, so that the movable arm 33 and the equipment mounting base 1 form a linear sliding pair that supports the two sliding relative to each other in the vertical direction.

[0029] This sliding pair serves as a guide and limiter, which helps improve the stability of the first roller 5 during its upward and downward movements.

[0030] Preferably, the third roller mechanism 4 further includes a servo motor 41 and a rotary arm 42; In actual setup, a servo motor 41 with deceleration function can be selected as needed, or a speed reducer can be installed. The servo motor 42 is mounted and fixed on the equipment mounting base 1. Its output end is mounted and connected to the front end of the rotary arm 42. The end of the rotary arm 42 serves as the output end of the third roller mechanism 4 and is rotatably mounted and connected to the third roller 7.

[0031] Preferably, the third roller mechanism 4 also includes a coupling and a torque sensor disposed between the servo motor 41 and the rotary arm 42; The output end of the servo motor 42 is connected and fixed to the input end of the torque sensor via a coupling, and the output end of the torque sensor is connected and fixed to the front end of the rotary arm 42 via a coupling. The torque sensor is used to monitor the magnitude of the output torque of the servo motor 41.

[0032] Preferably, the third roller mechanism 4 further includes an indexing scale 43; The scale 43 is located at the end of the rotary arm 42 and is fixed to the equipment mounting base 1. It is used to measure the revolution angle of the rotary arm 42.

[0033] When the slewing arm 42 is in its initial position, it should correspond to the zero mark on the scale 43.

[0034] A method for using a three-wheeled hemming tool to control the hemming of an automotive body-in-white by the three-wheeled hemming tool includes the following steps: The first step is to generate offline trajectory data. Using the second roller 6 as the reference position, and based on the digital model of the plate to be rolled, the robot offline simulation technology is used to output the offline trajectory data and node information of the second roller 6 in the rolling method. An offline trajectory is an approximation of a circular arc obtained by connecting multiple straight lines end to end. The more nodes there are, the smoother the offline trajectory becomes, i.e., the closer it is to a circular arc. In actual processing, offline trajectory data and node information can be obtained using the VC module output of PDPS; The second step is initial node calibration. 1) The robot moves, causing the three-wheeled hemming tool, which is its end effector, to move closer to the diaphragm of the plate to be hemmed, so that the reference position coincides with the initial node of the offline trajectory. 2) The staff observes the working status of the second roller 6, uses the six-axis freedom of the robot to adjust the position of the second roller 6 so that the working surface of the second roller 6 contacts the flange of the plate to be rolled, and at the same time ensures that the working surface of the second roller 6 completely covers the flange, and that at least 1mm of it extends out to the outside of the flange edge. The flange is a reserved part at the edge of the plate to be rolled for rolling and folding. The working surface of the second roller 4 extends at least 1mm beyond the outer edge of the flange to avoid the defect of the flange forming indentation. At this point, when the staff manually rolls the second roller 6, they should feel the sliding friction between the second roller 6 and the flange. There is a sticking sensation when manually moving the second roller 6; the 1mm length of the second roller 6 extending beyond the flange can be measured and ensured using a measuring tool such as a feeler gauge, as needed. 3) Maintain the contact state between the working surface of the second roller 6 and the flange. Utilize the linear motion of the first roller 5 driven by the first roller electric cylinder 31, the revolution of the third roller 7 driven by the servo motor 41, and the coordinated action of the robot's six-axis degrees of freedom to adjust the position of the first roller 5 and the third roller 7 by rotating the three-wheeled edge-rolling tool around the axis of the second roller 6. This ensures that the working surfaces of the first roller 5 and the third roller 7 completely cover the flange, with at least 1mm of the surface extending beyond the edge of the flange. At this time, when the staff manually rolls the first roller 5 and the third roller 7, they should feel the sliding friction between the first roller 5 and the third roller 7 and the flange. There is a sticking sensation when manually moving the first roller 5 and the third roller 7; the 1mm length of the first roller 5 and the third roller 7 extending beyond the flange can be measured and ensured using a measuring tool such as a feeler gauge, as needed. 4) The program records various parameters at this time, including the spatial coordinates of the reference position, the spatial coordinates and posture of the robot, the magnitude of the force output by the first roller electric cylinder 31, and the magnitude of the torque output by the servo motor 41. 5) Use the calibrated parameters obtained in step 4 as the parameter information of the initial node, and adjust the working posture of the robot and the three-wheeled hemming tool at the initial node position according to the parameter information in repetitive production. The third step is subsequent node calibration. The robot moves the three-wheeled hemming tool to the reference position to coincide with the next node. Then, the parameters of the node after calibration are obtained according to the methods in steps 2) to 4) of the second step. These parameters are used as the parameter information of the node. In repetitive production, the working posture of the robot and the three-wheeled hemming tool at the node position is adjusted according to the parameter information until all nodes are calibrated.

[0035] Step 4, Production By referring to the initial node parameter information and subsequent node parameter information in steps three and four, the work is repeated to achieve one-time rolling edge forming of workpiece flanging in batches.

[0036] Preferably, when performing the workpiece flanging and one-time edge forming according to the method in step four, if the difference between the magnitude of the force output by the first roller electric cylinder 31 and the magnitude of the torque output by the servo motor 41 obtained by real-time monitoring and the magnitude of the force output by the first roller electric cylinder 31 and the magnitude of the torque output by the servo motor 41 obtained in step two or three exceeds the preset allowable value, the edge forming tool stops.

[0037] This setting is used to ensure the safety of the hemming tool during operation. At this time, staff should be arranged to check the condition of the hemming tool on site in a timely manner and eliminate any possible malfunctions.

[0038] Preferably, in the second and third steps, when the program records various parameters, the staff records the rotation angle of the rotary arm 42 through the scale 43 to assist in observing and calibrating the posture of the three-wheeled hemming tool.

[0039] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0040] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A three-wheeled edge-rolling tool for edge-rolling forming of sheet metal, comprising a device mounting base (1) serving as a frame for the edge-rolling tool, the device mounting base (1) being mounted to a robot via a robot connecting base (2) disposed at its top, characterized in that: It also includes a first roller mechanism (3), a third roller mechanism (4), a first roller (5), a second roller (6) and a third roller (7); When the equipment mounting base (1) is in a standing position, the first roller (5), the second roller (6) and the third roller (7) are arranged sequentially along the rolling edge path, and the angle between the working surface of the three rollers and the horizontal plane increases progressively; the angle between the rotation axis of the first roller (5) and the projection of the tangent of the fetal membrane onto the horizontal plane does not exceed 15°. The first roller (5) is rotatably connected to the output end of the first roller mechanism (3) fixed to the equipment mounting base (1), and a rotating pair is formed between them to support the first roller (5) to rotate around its own axis. The output end of the first roller mechanism (3) outputs the movement that drives the first roller (5) to rise or fall in the vertical direction. The second roller (6) is rotatably mounted to the bottom end of the equipment mounting base (1), and a rotating pair is formed between the two to support the second roller (6) to rotate around its own axis; The third roller (7) is rotatably connected to the output end of the third roller mechanism (4) fixed to the equipment mounting base (1), and the two form a rotating pair that supports the third roller (7) to rotate around its own axis. The output end of the third roller mechanism (4) outputs a motion that drives the third roller (7) to revolve around a vertical rotary axis that deviates from its own axis.

2. The three-wheeled hemming tool according to claim 1, characterized in that: The first roller adjustment mechanism (3) includes a first roller electric cylinder (31) and a movable arm (33); The first roller electric cylinder (31) is installed and fixed on the equipment mounting base (1), and its output end is installed and connected to the front end of the movable arm (33). The end of the movable arm (33) serves as the output end of the first roller adjustment mechanism (3) and is rotatably installed and connected to the first roller (5).

3. A three-wheeled hemming tool according to claim 2, characterized in that: The first roller adjustment mechanism (3) is also provided with a connecting block (32) and a pressure sensor; The output end of the first roller electric cylinder (31) is connected to the front end of the movable arm (33) via a connecting block (32). The connecting block (32) is fixed to the output end of the first roller electric cylinder (31) and embedded in the front end of the movable arm (33). A pressure sensor is provided at the connection between the connecting block (32) and the movable arm (33).

4. A three-wheeled hemming tool according to claim 2 or 3, characterized in that: The movable arm (33) and the equipment mounting base (1) are provided with a first roller slider, and the other is provided with a first roller slide rail. The first roller slider and the first roller slide rail are slidably connected, so that the movable arm (33) and the equipment mounting base (1) form a linear sliding pair that supports the two sliding relative to each other in the vertical direction.

5. A three-wheeled hemming tool according to claim 1, characterized in that: The third roller mechanism (4) also includes a servo motor (41) and a rotary arm (42). The servo motor (42) is mounted and fixed on the equipment mounting base (1), and its output end is mounted and connected to the front end of the rotary arm (42). The end of the rotary arm (42) serves as the output end of the third roller mechanism (4) and is rotatably mounted and connected to the third roller (7).

6. A three-wheeled hemming tool according to claim 5, characterized in that: The third roller mechanism (4) also includes a coupling and a torque sensor located between the servo motor (41) and the rotary arm (42); The output end of the servo motor (42) is connected and fixed to the input end of the torque sensor through the coupling, and the output end of the torque sensor is connected and fixed to the front end of the rotary arm (42) through the coupling.

7. A three-wheeled hemming tool according to claim 5 or 6, characterized in that: The third roller mechanism (4) also includes a scale (43); The scale (43) is located at the end of the rotary arm (42) and is fixed to the equipment mounting base (1) to mark the revolution angle of the rotary arm (42).

8. A method for using a three-wheeled hemming tool, for controlling the three-wheeled hemming tool as described in any one of claims 1 to 3 to perform hemming forming on an automotive body-in-white, characterized in that, Includes the following steps: The first step is to generate offline trajectory data. Using the second roller (6) as the reference position, and based on the digital model of the plate to be rolled, the robot offline simulation technology is used to output the offline trajectory data and node information of the second roller (6) in the rolling process; The second step is initial node calibration. 1) The robot moves, causing the three-wheeled hemming tool, which is its end effector, to move closer to the diaphragm of the plate to be hemmed, so that the reference position coincides with the initial node of the offline trajectory. 2) The staff observes the working state of the second roller (6), uses the six-axis freedom of the robot to adjust the position of the second roller (6) so that the working surface of the second roller (6) contacts the flange of the plate to be rolled, and at the same time ensures that the working surface of the second roller (6) completely covers the flange, and that at least 1 mm of the part extends out to the outside of the flange edge. At this time, when the staff manually rolls the second roller (6), they should feel the sliding friction between the second roller (6) and the flange; 3) Maintain the contact state between the working surface of the second roller (6) and the flange. Utilize the linear motion of the first roller (5) driven by the first roller electric cylinder (31), the revolution of the third roller (7) driven by the servo motor (41), and the coordinated action of the robot's six-axis degrees of freedom to adjust the position of the first roller (5) and the third roller (7) by the overall rotation of the three-wheeled edge rolling tool around the axis of the second roller (6), so that the working surfaces of the first roller (5) and the third roller (7) completely cover the flange, with at least 1 mm of the portion extending to the outside of the flange edge. At this time, when the staff manually rolls the first roller (5) and the third roller (7), they should feel the sliding friction between the first roller (5) and the third roller (7) and the flange; 4) The program records various parameters at this time, including the spatial coordinates of the reference position, the spatial coordinates and posture of the robot, the magnitude of the force output by the first roller electric cylinder (31) and the magnitude of the torque output by the servo motor (41); 5) Use the calibrated parameters obtained in step 4 as the parameter information of the initial node, and adjust the working posture of the robot and the three-wheeled hemming tool at the initial node position according to the parameter information in repetitive production. The third step is subsequent node calibration. The robot moves the three-wheeled hemming tool to the reference position to coincide with the next node. Then, the parameters of the node after calibration are obtained according to the methods in steps 2) to 4) of the second step. These parameters are used as the parameter information of the node. In repetitive production, the working posture of the robot and the three-wheeled hemming tool at the node position is adjusted according to the parameter information until all nodes are calibrated. Step 4, Production By referring to the initial node parameter information and subsequent node parameter information in steps three and four, the work is repeated to achieve one-time rolling edge forming of workpiece flanging in batches.

9. The hemming method of a three-wheeled hemming tool according to claim 8, characterized in that: When performing the first-time edge forming of the workpiece according to the method of step four, if the difference between the magnitude of the force output by the first roller electric cylinder (31) and the magnitude of the torque output by the servo motor (41) obtained by real-time monitoring and the magnitude of the force output by the first roller electric cylinder (31) and the magnitude of the torque output by the servo motor (41) obtained in the second or third step exceeds the preset allowable value, the edge forming tool will stop.

10. The hemming method of a three-wheel hemming tool according to claim 8, characterized in that: In the second and third steps, when the program records various parameters, the staff records the rotation angle of the slewing arm (42) using the scale (43).

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