Self-adaptive track sanding device and method for complex curved surface

Abstract

The invention discloses a self-adaptive track sanding device and method for a complex curved surface. The device comprises a flange seat, a universal cross arranged at the front end of the flange seat, a motor body arranged in the universal cross, a brake ring and a polishing disc, wherein the brake ring and the polishing disc are arranged at the output end of the motor body; the universal cross is of a circular ring structure and is rotationally connected with the front end of the flange base through a first pin shaft, the upper portion of the motor body penetrates through the universal cross, and the motor body and the universal cross are rotationally connected through a second pin shaft. Connecting lines respectively formed by the first pin shaft and the second pin shaft are crossed, and the motor body realizes two-degree-of-freedom rotation through the first pin shaft and the second pin shaft. The motor body rotates through the universal cross to adjust the binding face between the grinding disc and the to-be-ground curved surface to achieve self-adaption to the to-be-ground curved surface, it can be guaranteed that the normal of the grinding disc coincides with the normal of the curved surface without precisely adjusting the posture and the positioning precision of a robot, and therefore the good grinding effect is obtained.

Description

Technical Field

[0001] The present invention belongs to the technical field of sanding equipment, and more specifically, relates to an adaptive orbital sanding device and method for complex curved surfaces. Background Art

[0002] Sanding machine is a kind of power tool widely used for surface grinding of workpieces. Orbital sanding machine is used to move the surface of sanded and polished objects with slight rotation or orbital motion to achieve fine surface grinding. At present, the sanding equipment used for robot grinding mostly uses manual disc grinding tools connected to force control tools through connecting flanges for grinding. The force control tools used for disc grinding tools generally use single-axis adaptive control of displacement and pressure. During the grinding process, it is necessary to ensure that the normal line of the grinding disc surface coincides with the normal line of the curved surface to obtain a more uniform grinding effect.

[0003] The Chinese patent with publication number CN106239319A discloses a sanding mechanism, which includes a connecting back plate, an upper plate, a lower plate, a motor and a sanding disc, wherein the upper plate is fixed on the connecting back plate, the upper plate and the lower plate are spaced apart and connected by a plurality of connecting rods, the upper end of the connecting rod is connected to the upper plate, and the lower end of the connecting rod is connected to the lower plate through a joint bearing; the motor is fixed on the upper end surface of the lower plate, and the output shaft of the motor passes through the lower plate and is fixedly connected to the sanding disc arranged below the lower plate. It has high flexibility, can not only polish flat surfaces but also sand surfaces with small curvatures, and also has the advantages of high production efficiency, good sanding quality, and effective protection of workpiece edges and corners.

[0004] However, the Chinese patent with publication number CN106239319A states that when the normal of the surface being polished does not coincide with the normal of the grinding disc, the contact point between the grinding disc and the surface is located at the edge of the grinding disc. The edge of the grinding disc transmits the downward force of the force control tool, and the linear speed of the edge of the grinding disc is relatively large. The surface after polishing is prone to depressions caused by over-polishing, and the surface as a whole is characterized by uneven polishing removal. Therefore, there is a need for an adaptive orbital sanding device and method for complex surfaces, which adds an adaptive surface mechanism to ensure that the normal of the grinding disc in the sanding equipment is adaptively aligned with the normal of the surface during the polishing of complex surfaces, thereby ensuring the uniformity of the polishing quality. Summary of the invention

[0005] In view of the above defects or improvement needs of the prior art, the present invention provides an adaptive orbital sanding device and method for complex surfaces, which enables the grinding disc to achieve universal rotation. Since the force points of the grinding disc are uneven or not in the center position, the motor body is rotated through the universal cross to adjust the fitting surface between the grinding disc and the surface to be polished to achieve adaptive grinding of the surface to be polished. There is no need to precisely adjust the robot posture and positioning accuracy to ensure that the normal line of the grinding disc coincides with the normal line of the surface, thereby obtaining a better grinding effect.

[0006] To achieve the above objectives, according to a first aspect of an embodiment of the present invention, there is provided an adaptive orbital sanding device for complex curved surfaces, comprising a flange seat, a universal cross disposed at the front end of the flange seat, a motor body disposed in the universal cross, and a brake ring and a grinding disc disposed at the output end of the motor body;

[0007] The universal cross is a circular ring structure, and is rotatably connected to the front end of the flange seat by a first pin shaft, and the upper part of the motor body passes through the universal cross, and the two are rotatably connected by a second pin shaft;

[0008] The connecting lines formed by the first pin shaft and the second pin shaft respectively cross each other, and the motor body can realize the rotation of two degrees of freedom through the two connecting lines.

[0009] Furthermore, the rear end of the flange seat is a cylinder with one end open, and the open end thereof is symmetrically provided with an extension portion as a mounting plate;

[0010] The universal cross is mounted on the front end of the mounting plate and rotates on the flange seat around the first pin shaft;

[0011] A fixing frame is arranged on the outer ring of the motor body, and the fixing frame is connected with the inner ring of the universal cross and rotates on the universal cross around the second pin shaft.

[0012] Furthermore, when the grinding disc contacts the surface to be polished, since the force points of the grinding disc are uneven or not in the center, the motor body is rotated through the universal cross to adjust the fitting surface between the grinding disc and the surface to be polished so that the normal line of the grinding disc coincides with the normal line of the surface to be polished.

[0013] Furthermore, the flange seat is also provided with a plurality of spring seats, which are evenly distributed on the end surface of the opening end of the flange seat and are located between the two mounting plates of the flange seat;

[0014] A spring is arranged between the spring seat and the fixing frame of the motor body. The multiple springs make the motor body evenly stressed. When not subjected to external force, under the action of the multiple springs, the motor body always keeps coincidence with the axis of the sanding device.

[0015] Furthermore, a dust cover is provided at the front end of the motor body, an air inlet is opened around the dust cover, and a plurality of guide plates are provided from the air inlet to the middle to form a guide plate array. A dust suction port is also provided on one side of the dust cover for connecting an external dust collector.

[0016] Furthermore, the motor body includes a motor housing, a rear end cover arranged at the rear end of the motor housing, a front end cover arranged at the front end of the motor housing, and a brushless motor arranged in the motor housing.

[0017] Furthermore, the motor housing is provided with holes evenly along the circumference, and a muffler is provided in the hole, and the rear end cover is provided with an air pipe joint for introducing compressed air, and a damping ring is provided between the motor housing and the rear end cover, and a plurality of small holes are provided on the damping ring as guide holes;

[0018] After compressed air is introduced into the air pipe joint, the airflow passes through the guide holes on the damping ring and enters the interior of the motor body, and then flows out from the muffler to dissipate the heat of the motor body. The compressed air is passed into the motor body to form a positive pressure in its internal space, preventing dust generated by the grinding disc at its front end from entering the interior.

[0019] Furthermore, an eccentric body is provided at the output end of the brushless motor, the center of the eccentric body is fixedly connected to the output shaft of the brushless motor, an eccentric block is provided at the front end away from the center, and a plurality of cooling fins are equidistantly provided along the end surface at the rear end to form a cooling fin array, and the cooling fin array is opposite to the guide plate array.

[0020] Furthermore, the grinding disc is installed in the eccentric block on the eccentric body through a connecting pin, and the connecting pin and the eccentric block are connected through a connecting bearing. The grinding disc and the eccentric body are always in an active state, and there is an eccentric distance between the grinding disc and the output shaft of the brushless motor.

[0021] According to a second aspect of an embodiment of the present invention, there is provided an adaptive orbital sanding method for a complex curved surface, which specifically comprises the following steps:

[0022] S100, connect the sanding device to the force control tool of the robot through the flange seat, and ensure that the motor body can achieve free rotation at multiple angles through the universal cross;

[0023] S200, adjusting the posture of the robot so that the grinding disc is roughly aligned with the position of the surface to be polished, starting the brushless motor, and the motor drives the grinding disc to rotate;

[0024] S300, when the grinding disc contacts the surface to be polished, because the force point of the grinding disc is uneven or not at the center, the motor body is adaptively adjusted in angle through the universal cross so that the normal line of the grinding disc coincides with the normal line of the surface to be polished;

[0025] S400, starting the external dust collector, the suction force generated by the dust collector enables the dust generated during the grinding process to be effectively sucked and collected;

[0026] S500, the rotation of the motor and the rotational motion of the eccentric force couple are combined into the rotational motion of the grinding disc through the eccentric body, and the friction between the brake ring and the grinding disc makes the motion trajectory of the sandpaper grains on the grinding disc a random cycloid motion;

[0027] S600, for the edge of the surface to be polished, use a single-acting cylinder to lock the normal direction of the polishing disc to prevent excessive deflection of the polishing disc during edge polishing, resulting in excessive polishing of the edge of the surface;

[0028] S700, when the sandpaper life is reached, the robot moves the sander to the automatic sandpaper tearing mechanism, and starts the single-acting cylinder to lock the normal direction of the sanding disc to prevent the sanding disc from swinging during the sandpaper tearing process, thereby improving the success rate of sandpaper replacement;

[0029] S800, after finishing the grinding, stop the brushless motor, brake the grinding disc quickly through the brake ring, and end the grinding operation.

[0030] In general, the above technical solutions conceived by the present invention can achieve the following beneficial effects compared with the prior art:

[0031] 1. In the sanding device of the present invention, the connecting line of the first pin shaft and the connecting lines of the second pin shafts at both ends cross each other, and the motor body realizes two degrees of freedom of rotation through the first pin shaft and the second pin shaft, so that the grinding disc can realize universal rotation. Since the force points of the grinding disc are uneven or not in the center position, the motor body is rotated through the universal cross to adjust the fitting surface between the grinding disc and the surface to be polished to realize adaptive grinding of the surface to be polished. It is not necessary to accurately adjust the robot posture and positioning accuracy to ensure that the normal line of the grinding disc coincides with the normal line of the surface, thereby obtaining a better grinding effect.

[0032] 2. In the sanding device of the present invention, multiple springs make the motor body evenly stressed. When not subject to external force, under the action of multiple springs, it always keeps coincidence with the axis of the sanding device. When the sanding device does not contact the surface to be polished, the gravity of the sanding device and the swing caused by external interference force are balanced to prevent accidental contact before friction when the sanding device contacts the surface to be polished, resulting in damage to the surface to be polished or local over-polishing.

[0033] 3. In the sanding device of the present invention, a sliding friction pair is formed between the brake ring and the grinding disc. During the grinding process, the friction resistance of the brake ring to the grinding disc makes the movement trajectory of the sandpaper sand grains on the grinding disc a random cycloidal motion, so that the surface quality obtained after grinding is more uniform, and during the shutdown process, the brake ring can quickly brake the grinding disc.

[0034] 4. In the sanding device of the present invention, the suction force generated by the external dust collector allows the outside air to enter the dust cover through the air inlet, and then flow on the heat dissipation fin array to drive the heat therein to achieve heat dissipation of the sanding device. At the same time, under the action of high-speed centrifugation, the dust particles escape from the edges of the heat dissipation fins and are finally sucked into the dust collector through the dust suction port, effectively preventing dust from entering the inside of the motor body or the bearing.

[0035] 5. In the sanding device of the present invention, the rotational motion of the grinding disc is a synthesis of the rotational motion of the motor and the rotational motion of the eccentric force couple generated by the rotational motion of the eccentric body on the grinding disc. During the grinding process, the movement trajectory of each sand grain on the sandpaper bonded on the grinding disc is a random orbit. The random movement of the sand grains during the grinding process can obtain a more uniform and uniform grinding quality.

[0036] 6. The sanding device of the present invention, when it is necessary to lock the normal direction of the sanding device, the piston rod of the single-acting cylinder acts on the concave circle on the motor body, and the sanding device will not be able to swing, thereby playing a locking role. When grinding the edge of a curved surface, the sanding device is locked to prevent the sanding device from swinging excessively and causing excessive grinding of the edge.

[0037] 7. In the sanding device of the present invention, after the life of the sandpaper is reached, when the robot moves the sanding machine to the automatic sandpaper tearing mechanism, the single-acting cylinder is started to lock the normal direction of the sanding disc to prevent the sanding disc from swinging during the sandpaper tearing process, thereby improving the success rate of sandpaper replacement. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 An exploded view of the structure of an adaptive orbital sanding device for complex curved surfaces according to an embodiment of the present invention;

[0039] Figure 2 It is a schematic structural diagram of an adaptive orbital sanding device for complex curved surfaces according to an embodiment of the present invention;

[0040] Figure 3 A schematic diagram of the positional relationship between the grinding disc and the surface to be ground in a traditional solution;

[0041] Figure 4 Schematic diagram of the positional relationship between the grinding disc and the surface to be ground in the solution of embodiment 1 of the present invention;

[0042] Figure 5 This is a schematic diagram of the structure of a motor body of an adaptive orbital sanding device for complex curved surfaces according to an embodiment of the present invention;

[0043] Figure 6 This is a schematic diagram of the installation of an eccentric body of an adaptive orbital sanding device for complex curved surfaces according to an embodiment of the present invention;

[0044] Figure 7 This is a schematic diagram of the installation of a single-acting cylinder of an adaptive orbital sanding device for complex curved surfaces according to an embodiment of the present invention;

[0045] Figure 8 Schematic diagram of the positional relationship between the grinding disc and the surface to be ground in the solution of embodiment 2 of the present invention;

[0046] Fig. 9The figure is a schematic flow chart of an adaptive orbital sanding method for complex curved surfaces according to an embodiment of the present invention.

[0047] In all the drawings, the same reference numerals represent the same technical features, specifically: 1-flange seat, 2-single-acting cylinder, 3-first pin shaft, 4-first oil-free bearing, 5-spring seat, 6-spring, 7-universal cross, 8-second pin shaft, 9-second oil-free bearing, 10-motor body, 11-dust cover, 12-brake ring, 13-grinding disc, 1001-trachea joint, 1002-concave ring, 1003-rear end cover, 1004-damping ring, 1005-motor housing, 1006-muffler, 1007-brushless motor, 1008-front end cover, 1009-eccentric body, 1010-connecting bearing, 1011-connecting shaft. DETAILED DESCRIPTION

[0048] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention. In addition, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0049] Example 1

[0050] like Figure 1 , 2 As shown, an embodiment of the present invention provides an adaptive orbital sanding device for complex curved surfaces, comprising a flange seat 1, a universal cross 7 arranged at the front end of the flange seat 1, a motor body 10 arranged in the universal cross 7, and a brake ring 12 and a grinding disc 13 arranged at the output end of the motor body 10. The universal cross 7 is a circular ring structure, connected to the front end of the flange seat 1 by a first pin 3 along a diameter, and the upper part of the motor body 10 passes through the universal cross 7, leaving a certain gap between the two, and the two are also connected along a diameter by a second pin 8. The connecting line of the first pin 3 and the connecting lines of the second pins 8 at both ends cross, and the motor body 10 realizes two degrees of freedom of rotation through the first pin 3 and the second pin 8, so that the grinding disc 13 can realize universal rotation, realize adaptive curved surface to be polished, and ensure that the normal line of the grinding disc coincides with the normal line of the curved surface without accurately adjusting the robot posture and positioning accuracy, thereby obtaining a better polishing effect.

[0051] The rear end of the flange seat 1 is a cylindrical body with one end open, and a plurality of mounting holes are opened at the bottom thereof. An extension portion is symmetrically provided from the open end to the front end as a mounting plate. The universal cross 7 is installed on the front end of the mounting plate through the first pin shaft 3, and rotates on the flange seat 1 around the first pin shaft 3. A fixing frame is provided on the outer ring of the motor body 10, and the fixing frame is rotationally connected to the inner ring of the universal cross 7 through the second pin shaft 8. When the grinding disc 13 contacts the curved surface to be polished, since the force point of the grinding disc 13 is uneven or not in the center position, the motor body 10 is rotated through the universal cross 7 to adjust the fitting surface between the grinding disc 13 and the curved surface to be polished, so that the normal line of the grinding disc 13 coincides with the normal line of the curved surface to be polished.

[0052] like Figure 3 , 4 As shown, the force control tool used in the conventional robot grinding and sanding equipment is only axially adaptive. When the normal line of the surface being ground does not coincide with the normal line of the grinding disc, the contact point between the grinding disc and the surface is located at the edge of the grinding disc. The edge of the grinding disc transmits the downward pressure of the force control tool, and the linear velocity of the edge of the grinding disc is relatively large. The surface after grinding is prone to depressions caused by over-grinding, and the surface as a whole is characterized by uneven grinding removal. In the present invention, the first pin 3, the universal cross 7, and the second pin 8 together form a ball and pin pair, through which two swinging degrees of freedom in the direction of the normal line of the grinding disc are released. During the grinding process, the grinding disc is adjusted by the surface itself, so that the grinding disc 13 of the sanding device can better fit the surface to be ground during the grinding process, ensuring that the grinding disc normal and the surface normal in the sanding equipment are adaptively fitted during the grinding of complex surfaces, thereby ensuring the uniformity of the grinding quality.

[0053] In order to ensure the flexibility of the ball-pin pair and reduce rotational wear, a first oil-free bearing 4 is installed at the connection between the first pin shaft 3 and the flange seat 1, and a second oil-free bearing 9 is installed at the connection between the motor body 10 and the universal cross 7. The universal cross has one degree of rotational freedom relative to the flange seat 1, and the motor body 10 has one degree of rotational freedom relative to the universal cross 7. During the grinding process, the sanding device passively adapts to the curved surface.

[0054] The flange seat 1 is also provided with a plurality of spring seats 5, which are evenly distributed on the open end surface of the flange seat 1 and are located between the two mounting plates of the flange seat 1. A spring 6 is provided between the spring seat 5 and the fixing frame of the motor body 10, and the plurality of springs 6 make the motor body 10 evenly stressed. When not subject to external force, under the action of the plurality of springs 6, it always keeps coincidence with the axis of the sanding device. When the sanding device does not contact the surface to be polished, the gravity of the sanding device and the swing caused by the external interference force are balanced to prevent accidental contact before friction when it contacts the surface to be polished, resulting in damage to the surface to be polished or partial over-polishing.

[0055] A dust cover 11 is also provided at the front end of the motor body 10. An air inlet is opened around the dust cover 11. A plurality of guide plates are provided from the air inlet to the middle to form a guide plate array. A dust suction port is also provided on one side of the dust cover 11 for connecting an external dust collector. During the grinding process, the dust collector generates suction, and air enters the dust cover 11 from the air inlet along the guide plate array, driving the dust generated by grinding to be sucked into the dust collector from the dust suction port to achieve the purpose of dust removal.

[0056] The brake ring 12 is a rubber ring, which forms a sliding friction pair with the grinding disc 13. During the grinding process, the friction resistance of the brake ring 12 on the grinding disc 13 makes the movement trajectory of the sandpaper sand grains on the grinding disc 13 a random cycloidal motion, so that the surface quality obtained after grinding is more uniform, and during the shutdown process, the brake ring 12 can quickly brake the grinding disc 13.

[0057] like Figure 5 , 6 As shown, the motor body 10 includes a motor housing 1005, a rear end cover 1003 disposed at the rear end of the motor housing 1005, a front end cover 1008 disposed at the front end of the motor housing 1005, and a brushless motor 1007 disposed in the motor housing 1005. The motor housing 1005 is also provided with holes uniformly opened along the circumference, and a muffler 1006 is provided in the hole. The rear end cover 1003 is also provided with an air pipe joint 1001 for passing compressed air. A damping ring 1004 is also provided between the motor housing 1005 and the rear end cover 1003, and a plurality of small holes are opened on the damping ring 1004 as guide holes. After the compressed air is passed into the air pipe joint 1001, the airflow passes through the guide holes on the damping ring 1004 and then enters the motor body 10, and then flows out from the muffler 1006, so as to dissipate heat for the motor body 10, and prevent the grinding effect from being affected by excessive temperature during operation. The compressed air is passed into the motor body 10 to form a positive pressure in the inner space thereof, thereby preventing dust generated by the grinding disc 13 at the front end from entering the inner space and damaging its parts, thereby extending the service life of the sanding device.

[0058] The output end of the brushless motor 1007 is provided with an eccentric body 1009, the center of which is fixedly connected to the output shaft of the brushless motor 1007, an eccentric block is provided at the front end away from the center, and a plurality of heat dissipation fins are equidistantly provided on the rear end along the end surface to form a heat dissipation fin array, which is opposite to the guide plate array. The suction force generated by the external dust collector allows the outside air to enter the dust cover 11 through the air inlet, and then flow on the heat dissipation fin array to drive the heat therein to achieve heat dissipation of the sanding device. At the same time, under the action of high-speed centrifugation, dust particles escape from the edge of the heat dissipation fins and are finally sucked into the dust collector through the dust suction port, effectively preventing dust from entering the motor body 10 or the bearing.

[0059] The grinding disc 13 is installed in the eccentric block on the eccentric body 1009 through the connecting pin 1011, and the connecting pin 1011 and the eccentric block are connected by the connecting bearing 1010, ensuring that there is no circumferential constraint between the connecting pin 1011 and the eccentric body 1009, that is, the grinding disc 13 and the eccentric body 1009 are always in an active state. The center of the pin 1011 and the center of the eccentric body 1009 are designed as an eccentric structure, that is, there is an eccentric distance between the grinding disc 13 and the output shaft of the brushless motor 1007. The rotational motion of the grinding disc 13 is a synthesis of the rotational motion of the motor and the eccentric force couple generated by the rotational motion of the eccentric body 1009 on the self-rotational motion of the grinding disc. During the grinding process, the motion trajectory of each sand grain on the bonded sandpaper on the grinding disc 13 is a random orbit, so that the random motion of the sand grains during the grinding process can obtain a more uniform and uniform grinding quality.

[0060] like Figure 7 As shown, the rear end cover 1003 is also provided with a concave ring 1002, which is embedded in the center of the rear end face of the rear end cover 1003, and the surface is a concave concave structure. The inner bottom of the flange seat 1 is also provided with a single-acting cylinder 2, and when the piston rod of the single-acting cylinder 2 is extended, it just abuts against the concave ring 1002. When it is necessary to lock the normal direction of the sanding device, the piston rod of the single-acting cylinder acts on the concave ring 1002 on the motor body 10, and the sanding device will not be able to swing, which plays a locking role. When grinding the edge of the curved surface, the sanding device is locked to prevent the sanding device from excessively swinging at the edge of the sanding edge, resulting in excessive grinding of the edge. And after the life of the sandpaper is reached, when the robot moves the sanding machine to the automatic sandpaper tearing mechanism, the single-acting cylinder is started to lock the normal direction of the sanding disc to prevent the sanding disc from swinging during the sandpaper tearing process, thereby improving the success rate of sandpaper replacement.

[0061] The flange seat 1 is also connected to a force control tool at the end of the robot through a flange, and the movement of the sanding device is controlled by the force control tool at the end of the robot.

[0062] Example 2

[0063] like Figure 8As shown, the embodiment of the present invention provides another adaptive orbital sanding device for complex curved surfaces. In this embodiment, other contents are the same as those in embodiment 1, except that: the ball-pin pair is arranged between the robot flange and the force control tool.

[0064] Example 3

[0065] like Fig. 9 As shown, an embodiment of the present invention provides an adaptive orbital sanding method for complex curved surfaces, which specifically includes the following steps:

[0066] S100, connecting the sanding device to the force control tool of the robot through the flange seat, and ensuring that the motor body 10 can achieve multi-angle free rotation through the universal cross 7;

[0067] S200, adjusting the robot posture so that the grinding disc 13 is roughly aligned with the position of the surface to be polished, and starting the brushless motor 1007, so that the motor drives the grinding disc 13 to rotate;

[0068] S300, when the grinding disc 13 contacts the surface to be polished, since the force point of the grinding disc 13 is uneven or not at the center, the motor body 10 is adaptively adjusted in angle through the universal cross 7 so that the normal line of the grinding disc 13 coincides with the normal line of the surface to be polished;

[0069] S400, starting the external dust collector, the suction force generated by the dust collector enables the dust generated during the grinding process to be effectively sucked and collected;

[0070] S500, the motor rotation and the eccentric force couple rotation motion are combined into the rotation motion of the grinding disc through the eccentric body 1009, and the friction between the brake ring 12 and the grinding disc 13 makes the motion trajectory of the sandpaper sand grains on the grinding disc a random cycloid motion;

[0071] S600: For the edge of the curved surface to be polished, use the single-acting cylinder 2 to lock the normal direction of the polishing disc 13 to prevent the excessive deflection of the polishing disc 13 during edge polishing, resulting in excessive polishing of the edge of the curved surface;

[0072] S700, after the life of the sandpaper is reached, when the robot moves the sander to the automatic sandpaper tearing mechanism, the single-acting cylinder 2 is started to lock the normal direction of the sanding disc 13 to prevent the sanding disc from swinging during the sandpaper tearing process, thereby improving the success rate of sandpaper replacement;

[0073] S800, after the grinding is completed, the brushless motor 1007 is stopped, and the grinding disc 13 is quickly braked by the brake ring 12 to end the grinding operation.

[0074] It will be easily understood by those skilled in the art that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. An adaptive orbital sanding device for complex curved surfaces, characterized in that: It comprises a flange seat (1), a universal cross (7) arranged at the front end of the flange seat (1), a motor body (10) arranged in the universal cross (7), and a brake ring (12) and a grinding disc (13) arranged at the output end of the motor body (10); The universal cross (7) is a circular ring structure, and is rotatably connected to the front end of the flange seat (1) via a first pin shaft (3); the upper part of the motor body (10) passes through the universal cross (7), and the two are rotatably connected via a second pin shaft (8); The connecting lines respectively formed by the first pin shaft (3) and the second pin shaft (8) cross each other, and the motor body (10) realizes rotation with two degrees of freedom through the two.

2. An adaptive orbital sanding device for complex curved surfaces according to claim 1, characterized in that: The rear end of the flange seat (1) is a cylinder with one end open, and the open end is symmetrically provided with an extension portion serving as a mounting plate; The universal cross (7) is mounted on the front end of the mounting plate and rotates on the flange seat (1) around the first pin shaft (3); A fixing frame is provided on the outer ring of the motor body (10), and the fixing frame is connected to the inner ring of the universal cross (7) and rotates on the universal cross (7) around the second pin shaft (8).

3. An adaptive orbital sanding device for complex curved surfaces according to claim 2, characterized in that: When the grinding disc (13) contacts the curved surface to be polished, since the force point of the grinding disc (13) is uneven or not at the center, the motor body (10) is rotated through the universal cross (7) to adjust the contact surface between the grinding disc (13) and the curved surface to be polished, so that the normal line of the grinding disc (13) coincides with the normal line of the curved surface to be polished.

4. An adaptive orbital sanding device for complex curved surfaces according to any one of claims 1 to 3, characterized in that: The flange seat (1) is also provided with a plurality of spring seats (5), the spring seats (5) being evenly distributed on the open end surface of the flange seat (1) and being located between the two mounting plates of the flange seat (1); A spring (6) is provided between the spring seat (5) and the fixing frame of the motor body (10). The plurality of springs (6) allow the motor body (10) to be uniformly stressed. When no external force is applied, the motor body (10) always keeps coincidence with the axis of the sanding device under the action of the plurality of springs (6).

5. An adaptive orbital sanding device for complex curved surfaces according to any one of claims 1 to 3, characterized in that: A dust cover (11) is also provided at the front end of the motor body (10), an air inlet is opened around the dust cover (11), and a plurality of guide plates are provided from the air inlet to the middle to form a guide plate array. A dust suction port is also provided on one side of the dust cover (11) for connecting to an external dust collector.

6. An adaptive orbital sanding device for complex curved surfaces according to any one of claims 1 to 3, characterized in that: The motor body (10) comprises a motor housing (1005), a rear end cover (1003) arranged at the rear end of the motor housing (1005), a front end cover (1008) arranged at the front end of the motor housing (1005), and a brushless motor (1007) arranged in the motor housing (1005).

7. An adaptive orbital sanding device for complex curved surfaces according to claim 6, characterized in that: The motor housing (1005) is also provided with holes evenly distributed along the circumference, and a muffler (1006) is provided in each of the holes; the rear end cover (1003) is also provided with an air pipe joint (1001) for introducing compressed air; a damping ring (1004) is also provided between the motor housing (1005) and the rear end cover (1003), and the damping ring (1004) is provided with a plurality of small holes serving as guide holes; After compressed air is introduced into the air pipe joint (1001), the airflow passes through the guide holes on the damping ring (1004) and enters the interior of the motor body (10), and then flows out from the muffler (1006) to dissipate heat for the motor body (10). The compressed air is introduced into the motor body (10) to form a positive pressure in its internal space, thereby preventing dust generated by the grinding disc (13) at its front end from entering the interior thereof during grinding.

8. An adaptive orbital sanding device for complex curved surfaces according to claim 7, characterized in that: An eccentric body (1009) is provided at the output end of the brushless motor (1007), the center of which is fixedly connected to the output shaft of the brushless motor (1007), an eccentric block is provided at the front end away from the center, and a plurality of cooling fins are equidistantly provided along the end surface at the rear end to form a cooling fin array, the cooling fin array being opposite to the guide plate array.

9. An adaptive orbital sanding device for complex curved surfaces according to claim 8, characterized in that: The grinding disc (13) is installed in the eccentric block on the eccentric body (1009) via a connecting pin (1011), and the connecting pin (1011) and the eccentric block are connected via a connecting bearing (1010). The grinding disc (13) and the eccentric body (1009) are always in an active state, and there is an eccentric distance between the grinding disc (13) and the output shaft of the brushless motor (1007).

10. An adaptive orbital sanding method for complex curved surfaces, implemented by using an adaptive orbital sanding device for complex curved surfaces as claimed in any one of claims 1 to 9, characterized in that: The specific steps include: S100, connecting the sanding device to the force control tool of the robot through the flange seat, and ensuring that the motor body (10) can achieve free rotation at multiple angles through the universal cross (7); S200, adjusting the posture of the robot so that the grinding disc (13) is roughly aligned with the position of the surface to be polished, and starting the brushless motor (1007), so that the motor drives the grinding disc (13) to rotate; S300, when the grinding disc (13) contacts the surface to be ground, because the force point of the grinding disc (13) is uneven or not at the center, the motor body (10) is adaptively adjusted in angle through the universal cross (7) so that the normal line of the grinding disc (13) coincides with the normal line of the surface to be ground; S400, starting the external dust collector, the suction force generated by the dust collector enables the dust generated during the grinding process to be effectively sucked and collected; S500, the rotation of the motor and the rotational motion of the eccentric force couple are combined into the rotational motion of the grinding disc through the eccentric body (1009), and friction is generated between the brake ring (12) and the grinding disc (13) so that the motion trajectory of the sandpaper grains on the grinding disc is a random cycloidal motion; S600, for the edge of the curved surface to be polished, use a single-acting cylinder (2) to lock the normal direction of the polishing disc (13) to prevent the excessive swing of the polishing disc (13) during edge polishing, resulting in excessive polishing of the edge of the curved surface; S700, when the life of the sandpaper is reached, the robot moves the sanding machine to the automatic sandpaper tearing mechanism, and starts the single-acting cylinder (2) to lock the normal direction of the sanding disc (13) to prevent the sanding disc from swinging during the sandpaper tearing process, thereby improving the success rate of sandpaper replacement; S800, after the grinding is completed, the brushless motor (1007) is stopped, and the grinding disc (13) is quickly braked by the brake ring (12), thereby ending the grinding operation.

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