Passive flexible grinding head with three degrees of freedom

Abstract

The utility model discloses a passive compliant polishing head with three degrees of freedom, which comprises a fixed platform, the lower surface of the fixed platform is rotatably connected with a compliant mechanical arm, the compliant mechanical arm comprises a large arm and a small arm, the compliant mechanical arm is rotatably connected with the upper surface of a movable platform, and the corresponding ends of the large arm and the small arm are mutually hinged. The other end of the large arm is rotationally connected with the fixed platform, the lower end of the small arm is rotationally connected with the movable platform, a rotating shaft penetrates through the movable platform and is rotationally connected with the movable platform through a second bearing, an end cover is arranged at the position of the second bearing, and the end cover is fixedly connected to the lower side of the movable platform and used for bearing the borne axial force. The pneumatic rotating shaft comprises an air storage bin and a rotating shaft, and fan blades are evenly distributed on the circumference of the rotating shaft. The utility model relates to the technical field of polishing, in particular to a passive flexible polishing head with three degrees of freedom to meet the requirement of curved surface machining, compensate positioning errors and achieve passive flexible polishing.

Description

Technical Field

[0001] The utility model relates to the technical field of grinding, in particular to a passive compliant grinding head with three degrees of freedom. Background Art

[0002] At present, the shutter industry is developing rapidly, with wide applications and high demand, and is widely used in various high-rise buildings and large factories. Among them, the grinding quality of the blade surface affects the performance of the blade. Choosing a suitable grinding head is particularly important for the blade grinding quality. There are various grinding devices, including series-parallel polishing mechanical arms and various large polishing devices. Most of the execution ends of these grinding devices are rigidly connected to the grinding head. Due to the parameter setting problem of the operator, there will be some positioning errors at the execution end. For some blades with a certain curvature, they cannot be fully polished, thus affecting the polishing quality. Therefore, it is very important to study a grinding head that adapts to the curvature change of the curved surface.

[0003] The utility model with authorization announcement number CN214923241U discloses a passive compliant grinding tool for the end of an industrial robot, comprising a robot mounting plate, a guide floating device and a grinding wheel; the guide floating device comprises an outer shell sleeve, an upper cover plate, a lower cover plate, an air motor, a ball guide shaft, an air motor mounting plate and an air motor fixing plate; the upper cover plate and the lower cover plate are respectively arranged at the two end positions of the outer shell sleeve, the ball guide shaft is arranged between the upper cover plate and the lower cover plate, the air motor mounting plate and the air motor fixing plate are respectively penetrated on the ball guide shaft through a ball spline bearing, one end of the air motor is fixed on the air motor mounting plate, and the other end is penetrated on the air motor fixing plate;

[0004] Wang Yu, Sun Long, Wang Yuwei, and Ning Jun designed a SEA-like flexible grinding device in "Anti-disturbance Control of Grinding Force of Flexible End of Wind Turbine Blade Grinding Robot" (China Automotive Technology and Research Center Co., Ltd., Tianjin 300300). The principle is to use a mobile platform composed of three universal wheels to achieve the bottom-level flexibility of the robot, and use the flexible control of the grinding module to achieve the high-level flexibility of the robot joints.

[0005] The grinding head mentioned above has few degrees of freedom and is slightly lacking in adaptability to blades with a certain curvature, thereby affecting the adequacy of blade grinding and affecting the quality of blade grinding. Utility Model Content

[0006] The utility model provides a passive compliant grinding head with three degrees of freedom, which can meet the requirements of curved surface processing, compensate for positioning errors, and realize passive compliant grinding.

[0007] A passive compliant grinding head with three degrees of freedom comprises a fixed platform, the lower surface of the fixed platform is rotatably connected to a compliant mechanical arm, the compliant mechanical arm comprises a large arm and a small arm, the compliant mechanical arm is rotatably connected to the upper surface of a moving platform, the corresponding ends of the large arm and the small arm are hinged to each other, the other end of the large arm is rotatably connected to the fixed platform, the lower end of the small arm is rotatably connected to the moving platform, a rotating shaft passes through the moving platform, the rotating shaft is rotatably connected to the moving platform through a second bearing, an end cover is arranged at the bearing, the end cover is fixedly connected to the lower side of the moving platform for bearing the axial force, the pneumatic rotating shaft comprises an air storage bin and a rotating shaft, fan blades are evenly distributed on the lower circumferential surface of the rotating shaft, the rotating shaft is arranged in the cavity of the air storage bin, the fan blades fix the rotating shaft, the rotating shaft is rotatably connected to the air storage bin through a first bearing, and the grinding head is connected to the rotating shaft through a threaded connection;

[0008] A bracket is provided on the upper surface of the moving platform, and the bracket is used to support the pneumatic rotating shaft and bear the axial force exerted on the bearing. The bracket is fixed on the upper side of the moving platform, and the bracket is rotatably connected to the pneumatic rotating shaft. The laser ranging sensor is arranged on the lower side of the moving platform and is fixedly connected to the lower side of the moving platform, and is used to measure the distance between the grinding head and the grinding workpiece.

[0009] As a further limitation of the present technical solution, an air inlet and an air outlet are provided on the side of the air storage bin.

[0010] As a further limitation of the technical solution, the centers of the upper arm and the lower arm are respectively rotatably connected with cylindrical pins, and the two cylindrical pins on the same side are connected by an elastic structure.

[0011] As a further limitation of the present technical solution, the elastic structure includes a spring and a telescopic cylinder, one end of the outer shell of the telescopic cylinder is fixed to the cylindrical pin connected to the middle part of the upper arm, the outer end of the telescopic rod of the telescopic cylinder is fixed to the cylindrical pin connected to the middle part of the lower arm, the spring ring is sleeved on the telescopic cylinder, and the two ends of the spring are respectively fixed to the two ends of the telescopic cylinder.

[0012] As a further limitation of the technical solution, a coating layer is provided on the lower surface of the grinding head, and the coating layer is made of polyurethane rubber.

[0013] As a further limitation of the present technical solution, the upper side of the gas storage bin is matched with a gas storage bin cover.

[0014] Compared with the prior art, the advantages and positive effects of the utility model are:

[0015] The passive compliant robotic arm is small in size, light in weight, and flexible in movement. The robotic arm is made of rigid material with high elastic modulus, high strength, and high hardness.

[0016] The passive compliant robot arm is connected to the moving platform and the fixed platform through a revolute pair, which can realize three-degree-of-freedom movement, effectively compensate for the positioning error of the parallel robot arm, realize passive compliant grinding, and make the grinding sufficient;

[0017] The grinding head is connected to the rotating shaft through a thread, and different grinding heads can be replaced according to the material of the shutter blades to be polished. There is a layer of polyurethane rubber on the grinding material of the grinding head, which makes it more flexible when contacting the polishing workpiece. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The drawings described herein are used to provide a further understanding of the present application and constitute a part of the present application. The illustrative embodiments of the present application and their descriptions are used to explain the present application and do not constitute an improper limitation on the present application. Obviously, the drawings described below are only some embodiments of the present utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work. In the drawings:

[0019] Figure 1 The utility model is a passive compliant grinding head with three degrees of freedom. Figure 1 .

[0020] Figure 2 The utility model is a schematic diagram of the internal structure of a pneumatic rotating shaft of a passive compliant grinding head with three degrees of freedom without the air storage bin cover.

[0021] Figure 3 The utility model is a schematic diagram of the connection between the pneumatic rotating shaft and the moving platform of a passive compliant grinding head with three degrees of freedom.

[0022] Figure 4 It is a half-section view of the connection mode between the pneumatic rotating shaft and the moving platform of a passive compliant grinding head with three degrees of freedom of the utility model.

[0023] Figure 5 The utility model is a passive compliant grinding head with three degrees of freedom. Figure 2 .

[0024] In the figure: 1. fixed platform; 2. rotating shaft; 3. upper arm; 4. lower arm; 5. grinding head; 6. moving platform; 7. bearing 1; 8. air storage chamber; 9. spring; 10. fan blade; 11. air inlet; 12. air storage chamber; 13. air outlet; 14. flexible robotic arm; 15. telescopic cylinder; 16. laser ranging sensor; 17. air storage chamber cover; 19. bracket; 20. coating layer; 21. bearing 2; 22. pneumatic rotating shaft; 23. cylindrical pin. DETAILED DESCRIPTION

[0025] The following is combined with Figure 1-Figure 5The utility model is further described with implementation modes.

[0026] The specific embodiments of the present utility model are:

[0027] A passive compliant grinding head with three degrees of freedom comprises a fixed platform 1, the lower surface of the fixed platform 1 is rotatably connected to a compliant mechanical arm 14, the compliant mechanical arm 14 comprises a large arm 3 and a small arm 4, the compliant mechanical arm is rotatably connected to the upper surface of a moving platform 6, the corresponding ends of the large arm 3 and the small arm 4 are hinged to each other, the other end of the large arm 3 is rotatably connected to the fixed platform 1, the lower end of the small arm 4 is rotatably connected to the moving platform 6, a rotating shaft 2 passes through the moving platform 6, and the rotating shaft 2 is connected to the moving platform 6 by a bearing 21 The movable platform 6 is rotatably connected, and an end cover 18 is arranged at the bearing 21. The end cover 18 is fixedly connected to the lower side of the movable platform 6 to bear the axial force. The pneumatic shaft 22 includes an air storage bin 8 and a shaft 2. The fan blades 10 are evenly distributed on the lower circumferential surface of the shaft 2. The shaft 2 is arranged in the cavity of the air storage bin 8. The fan blades 10 fix the shaft 2. The shaft 2 is rotatably connected to the air storage bin 8 through a bearing 7. The grinding head 5 is connected to the shaft 2 through a thread.

[0028] A bracket 19 is provided on the upper surface of the moving platform 6, and the bracket 19 is used to support the pneumatic rotating shaft 22 and bear the axial force of the bearing. The bracket 19 is fixed on the upper side of the moving platform 6, and the bracket 19 is rotatably connected to the pneumatic rotating shaft 22. The laser ranging sensor 16 is arranged on the lower side of the moving platform 6 and is fixedly connected to the lower side of the moving platform 6, and is used to measure the distance between the grinding head 5 and the grinding workpiece.

[0029] As a further limitation of the present technical solution, an air inlet 11 and an air outlet 13 are provided on the side of the air storage bin 8 .

[0030] As a further limitation of the technical solution, the centers of the upper arm 3 and the lower arm are respectively rotatably connected to the cylindrical pins 23, and the two cylindrical pins 23 on the same side are connected by an elastic structure.

[0031] As a further limitation of the present technical solution, the elastic structure includes a spring 9 and a telescopic cylinder 15, one end of the outer shell of the telescopic cylinder 15 is fixed to the cylindrical pin 23 connected to the middle part of the upper arm 3, the outer end of the telescopic rod of the telescopic cylinder 15 is fixed to the cylindrical pin 23 connected to the middle part of the lower arm 4, the spring 9 is looped around the telescopic cylinder 15, and the two ends of the spring 9 are respectively fixed to the two ends of the telescopic cylinder 15.

[0032] As a further limitation of the present technical solution, a coating layer 20 is provided on the lower surface of the grinding head 5 , and the material of the coating layer is polyurethane rubber.

[0033] As a further limitation of the present technical solution, the upper side of the gas storage bin 8 is matched with a gas storage bin cover 17 .

[0034] The working principle of this embodiment is:

[0035] High-pressure gas enters the air storage chamber 12 through the air inlet and is output through the air outlet 13, forming a pressure difference to blow the fan blade 10 to rotate, and the rotation of the fan blade drives the rotating shaft 2 to rotate, and the rotating shaft drives the grinding head 5 to rotate. When the blade to be ground by the grinding head has a certain curvature, due to the rotation connection of the upper arm 3 and the lower arm 4, the flexible mechanical arm 14 realizes the movement along the X-axis and Y-axis and the rotation along the Z-axis (such as Figure 1 For the main view, the main viewing direction is the Z-axis direction, the side viewing direction is the X-axis direction, and the top viewing direction is the Y-axis direction, and the same applies below). It can compensate for the positioning error caused by insufficient positioning of the grinding device, automatically compensate for the positioning error, realize passive grinding, and improve the grinding accuracy and sufficiency. The laser ranging sensor 16 is installed on the lower side of the moving platform 6 to monitor the distance between the grinding head 5 and the grinding workpiece in real time to ensure the accuracy during the grinding process. The grinding head is connected to the rotating shaft through a thread, and different grinding heads can be replaced according to the material of the shutter blades. There is a layer of polyurethane rubber on the grinding material of the grinding head, which makes it more flexible when contacting the grinding workpiece.

[0036] The working process is: the pneumatic device connects the high-pressure gas to the gas storage bin 8, and adjusts the rotation speed of the fan blade 10 by controlling the air intake and air outlet, thereby controlling the rotation speed of the grinding head 5 and adjusting the flexible robotic arm: when grinding the workpiece, due to the existence of the flexible robotic arm, the grinding head can follow the movement of the flexible robotic arm along the X-axis and Y-axis and the rotation of the Z-axis to make up for the positioning error caused by insufficient positioning of the grinding device, automatically compensate for the positioning error, and realize the grinding head 5 to adapt to the curved shape of the grinding position, so that the grinding head 5 can fit the surface of the workpiece to realize passive grinding, and monitor the distance between the grinding head and the workpiece in real time through the feedback of the laser ranging sensor 16. If necessary, adjust the rotation speed of the pneumatic shaft 22 or the position of the flexible robotic arm 14 to ensure the grinding quality.

[0037] The above description is only an embodiment of the present invention, and does not limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made by using the contents of the specification and drawings of the present invention, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A passive compliant grinding head with three degrees of freedom, characterized by: The invention comprises a fixed platform (1), the lower surface of the fixed platform (1) is rotatably connected to a compliant mechanical arm, the compliant mechanical arm comprises a large arm (3) and a small arm (4), the compliant mechanical arm is rotatably connected to the upper surface of a moving platform (6), the corresponding ends of the large arm (3) and the small arm (4) are hinged to each other, the other end of the large arm (3) is rotatably connected to the fixed platform (1), the lower end of the small arm (4) is rotatably connected to the moving platform (6), a rotating shaft (2) passes through the moving platform (6), and the rotating shaft (2) is rotatably connected to the moving platform (6) via a second bearing (21). The bearing 2 (21) is provided with an end cover, which is fixedly connected to the lower side of the moving platform (6) for bearing the axial force. The pneumatic shaft (22) includes an air storage bin (8) and the shaft (2). The lower circumferential surface of the shaft (2) is evenly distributed with blades (10). The shaft (2) is arranged in the cavity of the air storage bin (8). The blades (10) fix the shaft (2). The shaft (2) is rotatably connected to the air storage bin (8) via a bearing 1 (7). The grinding head (5) is connected to the shaft (2) via a thread. A bracket (19) is provided on the upper surface of the moving platform (6), and the bracket (19) is used to support the pneumatic rotating shaft (22) and bear the axial force. The bracket (19) is fixed on the upper side of the moving platform (6), and the bracket (19) is rotatably connected to the pneumatic rotating shaft (22). A laser distance measuring sensor (16) is provided on the lower side of the moving platform (6) and is fixedly connected to the lower side of the moving platform (6), and is used to measure the distance between the grinding head (5) and the grinding workpiece.

2. A passive compliant grinding head with three degrees of freedom according to claim 1, characterized in that: An air inlet (11) and an air outlet (13) are arranged on the side of the air storage bin (8).

3. A passive compliant grinding head with three degrees of freedom according to claim 2, characterized in that: The centers of the upper arm (3) and the lower arm (4) are respectively rotatably connected to cylindrical pins (23), and the two cylindrical pins (23) on the same side are connected via an elastic structure.

4. A passive compliant grinding head with three degrees of freedom according to claim 3, characterized in that: The elastic structure comprises a spring (9) and a telescopic cylinder (15); one end of the outer shell of the telescopic cylinder (15) is fixed to the cylindrical pin (23) connected to the middle of the upper arm (3); the outer end of the telescopic rod of the telescopic cylinder (15) is fixed to the cylindrical pin (23) connected to the middle of the lower arm (4); the spring (9) is sleeved around the telescopic cylinder (15); and the two ends of the spring (9) are respectively fixed to the two ends of the telescopic cylinder (15).

5. A passive compliant grinding head with three degrees of freedom according to claim 4, characterized in that: The lower surface of the grinding head (5) is provided with a coating layer (20), and the coating layer (20) is made of polyurethane rubber.

6. A passive compliant grinding head with three degrees of freedom according to claim 5, characterized in that: The upper side of the gas storage bin (8) is matched with a gas storage bin cover (17).

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