Six-degree-of-freedom robot shape follow-up grinding device supported by follow-up variable stiffness

Abstract

The six-degree-of-freedom robot shape follow-up grinding device is used for robot grinding of large complex curved-surface thin-wall parts, grinding vibration suppression and deformation control are achieved, and the six-degree-of-freedom robot shape follow-up grinding device comprises a six-degree-of-freedom magneto-rheological grinding pose fine adjustment mechanism, a six-degree-of-freedom magneto-rheological grinding pose fine adjustment mechanism, a six-degree-of-freedom magneto-rheological grinding pose fine adjustment mechanism and a six-degree-of-freedom magneto-rheological grinding pose fine adjustment mechanism. The servo variable-rigidity supporting mechanism is arranged on the base. According to the main thought, a six-degree-of-freedom compliant shape follow-up grinding mechanism and a follow-up variable-rigidity supporting clamp are designed, the six-degree-of-freedom shape follow-up grinding mechanism can adjust the pose of a grinding head in a self-adaptive mode according to the shape of the curved surface, and it is guaranteed that the grinding head is tangent to the curved surface; the follow-up variable-rigidity supporting clamp can clamp the grinding area of the workpiece in real time, move along with the grinding head of the robot and continuously provide controllable air pressure for the other side of the grinding area, a supporting clamp occupying a large space does not need to be provided for the other side of the workpiece, deformation in the grinding process of the thin-wall workpiece is reduced, and grinding flutter is restrained.

Description

Technical Field

[0001] The present invention relates to the field of large thin-walled parts grinding, and in particular to a six-degree-of-freedom robot conformal grinding device with a dynamic variable stiffness support. Background Art

[0002] In modern industrial production, large thin-walled parts are increasingly used, such as large wing skins and spacecraft cabin shells in the aerospace field; body panels in the automotive manufacturing field; and large container shells in the mechanical manufacturing field. These parts play a key role in their respective systems, but due to their own characteristics, they face many challenges in grinding, such as conformal grinding of complex surfaces, grinding deformation, and grinding vibration. At present, grinding robots are mainly used for strong rigid components and components with regular shapes, and it is difficult to adapt to the grinding needs of large thin-walled parts with complex curved surfaces. Therefore, it is of great significance to develop a robot grinding device for large thin-walled parts. Summary of the invention

[0003] In order to solve the above problems, the present invention specifically proposes a six-degree-of-freedom robot conformal grinding device solution with a dynamic variable stiffness support.

[0004] The technical solution adopted by the present invention to solve the technical problem is: a follow-up variable stiffness support mechanism and a multi-degree-of-freedom grinding mechanism, which is characterized by comprising a six-degree-of-freedom magnetorheological grinding posture fine-tuning mechanism (28), a follow-up variable stiffness support mechanism (29), a pneumatic grinding device (27), and a force sensor device (30).

[0005] The six-degree-of-freedom magnetorheological grinding posture fine-tuning mechanism (28) comprises: an upper fixed plate (1), a first joint ball bearing (2), a second joint ball bearing (3), an electric cylinder connection block (4), a first electric cylinder (5), a first electric cylinder shaft (6), a universal joint (7), a magnetorheological damper (8), a connector (9), and a lower fixed plate (10). The universal joint (7) is connected to the lower surface of the upper fixed plate (1) by bolts; the first electric cylinder (5) is connected to the lower surface of the electric cylinder connection block (4) by bolts; the upper surface of the electric cylinder connection block (4) is provided with a first joint ball bearing (2); the end of the first electric cylinder shaft (6) is connected to the second joint ball bearing (3), thereby ensuring that the upper fixed plate (1) and the lower fixed plate (10) can both rotate freely around the ball bearing; the second joint ball bearing (3) is provided at the center position of the upper surface of the lower fixed plate (10); the universal joint (7) is connected to the lower fixed plate (10) by bolts. ) upper surface; the connector (9) is protrudingly connected to one end of the universal joint (7); the upper end of the magnetorheological damper (8) is connected to the universal joint (1) corresponding to the upper fixed plate (1), and the lower end is connected to the upper surface of the connector (9). A total of six magnetorheological dampers (8) are divided into three groups and arranged symmetrically in a circular pattern, so that the follow-up variable stiffness support mechanism has six degrees of freedom (29) and has sufficient flexibility to achieve position adjustment and posture control of the grinding head. At the same time, the magnetorheological damper (8) has a damping control function and can suppress the vibration of the workpiece and the spindle when the robot is grinding the workpiece.

[0006] The variable stiffness follower support mechanism (29) comprises: a front roller support plate (11), a front first follower support rod (12), a front second follower support rod (13), a front follower support block (14), a front universal roller (15), and a front magnet (16); a rear roller support plate (17), a rear first follower support rod (18), a rear second follower support rod (19), a rear follower support block (20), a rear universal roller (21), a rear magnet (22), a second electric cylinder (23), a second electric cylinder shaft (24), a dome block (25), a thin-walled member (26), and an L-shaped plate (31); the front first follower support rod (12) is connected to the lower surface of the front roller support plate (11) by bolts; the front second follower support rod (13) is connected to the groove of the front first follower support rod (12), and the second follower support rod ( 13) can slide in the groove of the first follower support rod (12), and the second follower support rod (13) is provided with a notch, and an axle pin can be installed on the gap hole on the first follower support rod (12) to pass through the notch of the second follower support rod (13), so that the second follower support rod (13) can only slide up and down in the vertical direction; the front end follower support block (14) is connected to the lower surface of the front end second follower support rod (13) by bolts; the front end magnet (16) is connected to the lower surface of the front end follower support block (14) by bolts; the front end universal roller (15) is connected to the lower surface of the front end follower support block (14) by bolts, and the front end universal roller (15) maintains a distance of about 1 mm from the front end magnet (16) in the direction perpendicular to the contact surface of the workpiece, thereby achieving the purpose of only the front end universal roller (15) contacting the workpiece (26) during the processing. The first follower support rod (18) at the rear end is connected to the lower surface of the rear roller support plate (17) by bolts; the second follower support rod (19) at the rear end is connected to the groove of the first follower support rod (18) at the rear end; the follower support block (20) at the rear end is connected to the lower surface of the second follower support rod (19) at the rear end by bolts; the rear magnet (22) at the rear end is connected to the lower surface of the follower support block (20) at the rear end by bolts; the universal roller (21) at the rear end is connected to the follower support block (20) at the rear end by bolts. The lower surface of the support block (20); the thin-walled part (26) is clamped between the front universal roller (15) and the rear universal roller (21); the second electric cylinder (23) is connected to the rear roller support plate (17) by bolts, and the dome block (25) is connected to the top of the second electric cylinder shaft (24). Through the force sensor device (30), the first electric cylinder (5) and the second electric cylinder (23) can adjust the size of the air pressure during the grinding process, thereby reducing the deformation of the thin-walled part robot grinding position.

[0007] The force sensor device (30) is connected to the center of the lower surface of the front roller support plate (11), so that the data obtained by the force sensor device (30) is accurate; the pneumatic grinding device (27) is connected to the force sensor device (30) via an L-shaped plate (31).

[0008] Preferably, there are six magnetorheological dampers (8) which are circumferentially symmetrically arranged between the upper fixing plate (1) and the lower fixing plate (10).

[0009] Preferably, the front second follower support rod (13) and the rear second follower support rod (19) are provided with notches.

[0010] Preferably, the front universal roller (15) maintains a distance of about 1 mm from the front magnet (16) in a direction perpendicular to the contact surface of the workpiece, thereby achieving the purpose of only the front universal roller (15) being in contact with the workpiece (26) during the processing.

[0011] Preferably, the six magnetorheological dampers (8) have a damping control function, which can suppress the vibration of the workpiece and the spindle when the robot is grinding the workpiece.

[0012] Preferably, the follow-up variable stiffness support mechanism (29) is a force-controlled follow-up variable stiffness support mechanism, which can follow the movement of the grinding head, reduce deformation of thin-walled parts during grinding, and improve grinding accuracy.

[0013] The beneficial effects of the present invention are:

[0014] The six-degree-of-freedom magnetorheological grinding posture fine-tuning mechanism (28) of the present invention can adaptively adjust the posture of the grinding head according to the shape of the curved surface, thereby ensuring that the grinding head is tangent to the curved surface;

[0015] The six magnetorheological dampers (8) of the present invention have a damping control function and can suppress the vibration of the workpiece and the spindle when the robot is grinding the workpiece, thereby obtaining better grinding accuracy.

[0016] The follow-up variable stiffness support mechanism (28) of the present invention can clamp the grinding area of ​​the workpiece in real time during robot grinding, follow the movement of the robot grinding head, and continuously provide controllable air pressure to the other side of the grinding area, without providing a support fixture or auxiliary support robot that occupies a large space on the other side of the workpiece, thereby reducing the work area occupied, reducing deformation during the grinding process of thin-walled parts, suppressing grinding vibration, and obtaining better grinding accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 The present invention is a schematic diagram of a grinding process of a dynamic variable stiffness support mechanism and a multi-degree-of-freedom grinding mechanism.

[0018] Figure 2It is a schematic diagram of the overall structure of a dynamic variable stiffness support mechanism and a multi-degree-of-freedom grinding mechanism of the present invention.

[0019] Figure 3 It is a schematic diagram of a six-degree-of-freedom grinding posture fine-tuning mechanism of a dynamic variable-rigidity support mechanism and a multi-degree-of-freedom grinding mechanism of the present invention.

[0020] Figure 4 It is a schematic diagram of a servo-variable-rigidity support mechanism of a servo-variable-rigidity support mechanism and a multi-degree-of-freedom grinding mechanism of the present invention.

[0021] Figure 5 It is a partial view of a front end follow-up support rod and a universal roller of a follow-up variable stiffness support mechanism and a multi-degree-of-freedom grinding mechanism of the present invention.

[0022] The reference numerals in the figures are as follows:

[0023] 1. Fixing plate; 2. First joint ball bearing; 3. Second joint ball bearing; 4. Electric cylinder connection block; 5. First electric cylinder; 6. First electric cylinder shaft; 7. Universal joint; 8. Magnetorheological damper; 9. Connector; 10. Lower fixing plate; 11. End roller support plate; 12. Front first follower support rod; 13. Front second follower support rod; 14. Front follower support block; 15. Front universal roller; 16. Front magnet; 17. Rear roller support plate; 1 8. The first follower support rod at the rear end; 19. The second follower support rod at the rear end; 20. The follower support block at the rear end; 21. The universal roller at the rear end; 22. The magnet at the rear end; 23. The second electric cylinder; 24. The second electric cylinder shaft; 25. The dome block; 26. The workpiece; 31. The L-shaped plate; 28. The six-degree-of-freedom magnetorheological grinding posture fine-tuning mechanism; 29. ​​The follower variable stiffness support mechanism; 27. The pneumatic grinding device; 30. The force sensor device; 32. The industrial robot; 33. The vise; DETAILED DESCRIPTION

[0024] The present invention is further described below in conjunction with the accompanying drawings and embodiments. It will be understood that the specific embodiments described herein are only used to explain the present invention rather than to limit the present invention. It should also be noted that, for ease of description, only parts related to the present invention rather than all structures are shown in the accompanying drawings.

[0025] In the description of the present invention, unless otherwise clearly stipulated and limited, the terms "connected", "connected" and "fixed" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integrated connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements; for ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0026] In the present invention, unless otherwise clearly stipulated and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them; furthermore, a first feature being "above", "above" and "above" the second feature includes the first feature being directly above and diagonally above the second feature, or simply means that the first feature is higher in level than the second feature; a first feature being "below", "below" and "below" the second feature includes the first feature being directly below and diagonally below the second feature, or simply means that the first feature is lower in level than the second feature.

[0027] like Figure 1 As shown, the follow-up variable stiffness support mechanism and the multi-degree-of-freedom grinding mechanism are installed at the end of the industrial robot (32), and the thin-walled workpiece (26) is fixed on the vise (33). Through the magnetic attraction function of the follow-up variable stiffness support mechanism (29), the workpiece to be processed is stably clamped in the middle, and the grinding of the workpiece (26) can be achieved by controlling the industrial robot to run according to a predetermined trajectory.

[0028] like Figure 2 As shown, a follow-up variable stiffness support mechanism and a multi-degree-of-freedom grinding mechanism include a six-degree-of-freedom magnetorheological grinding posture fine-tuning mechanism (28), a follow-up variable stiffness support mechanism (29), a pneumatic grinding device (27), and a force sensor device (30).

[0029] like Figure 3As shown, the six-degree-of-freedom magnetorheological grinding posture fine-tuning mechanism (28) includes: an upper fixed plate (1), a first joint ball bearing (2), a second joint ball bearing (3), an electric cylinder connection block (4), a first electric cylinder (5), a first electric cylinder shaft (6), a universal joint (7), a magnetorheological damper (8), a connector (9), and a lower fixed plate (10). The universal joint (7) is connected to the lower surface of the upper fixed plate (1) by bolts; the first electric cylinder (5) is connected to the lower surface of the electric cylinder connection block (4) by bolts; the upper surface of the electric cylinder connection block (4) is provided with a first joint ball bearing (2); the end of the first electric cylinder shaft (6) is connected to the second joint ball bearing (3), thereby ensuring that the upper fixed plate (1) and the lower fixed plate (10) can both rotate freely around the ball bearing; the second joint ball bearing (3) is provided at the center position of the upper surface of the lower fixed plate (10); the universal joint (7) is connected to the lower fixed plate (10) by bolts. ) upper surface; the connector (9) is protrudingly connected to one end of the universal joint (7); the upper end of the magnetorheological damper (8) is connected to the universal joint (1) corresponding to the upper fixed plate (1), and the lower end is connected to the upper surface of the connector (9). A total of six magnetorheological dampers (8) are divided into three groups and arranged symmetrically in a circular pattern, so that the follow-up variable stiffness support mechanism has six degrees of freedom (29) and has sufficient flexibility to achieve position adjustment and posture control of the grinding head. At the same time, the magnetorheological damper (8) has a damping control function and can suppress the vibration of the workpiece and the spindle when the robot is grinding the workpiece.

[0030] like Figure 4As shown, the follow-up variable stiffness support mechanism (29) comprises a front roller support plate (11), a front first follow-up support rod (12), a front second follow-up support rod (13), a front follow-up support block (14), a front universal roller (15), and a front magnet (16); a rear roller support plate (17), a rear first follow-up support rod (18), a rear second follow-up support rod (19), a rear follow-up support block (20), a rear universal roller (21), a rear magnet (22), a second electric cylinder (23), a second electric cylinder shaft (24), a dome block (25), a thin-walled member (26), and an L-shaped plate (31); the front first follow-up support rod (12) is connected to the lower surface of the front roller support plate (11) by bolts; the front second follow-up support rod (13) is connected to the groove of the front first follow-up support rod (12), and the second follow-up support rod (13) can slide in the groove of the first follower support rod (12), and the second follower support rod (13) is provided with a notch, and an axle pin can be installed on the gap hole on the first follower support rod (12) to pass through the notch of the second follower support rod (13), so that the second follower support rod (13) can only slide up and down in the vertical direction; the front end follower support block (14) is connected to the lower surface of the front end second follower support rod (13) by bolts; the front end magnet (16) is connected to the lower surface of the front end follower support block (14) by bolts; the front end universal roller (15) is connected to the lower surface of the front end follower support block (14) by bolts, and the front end universal roller (15) maintains a distance of about 1 mm from the front end magnet (16) in a direction perpendicular to the contact surface of the workpiece, thereby achieving the purpose of only the front end universal roller (15) contacting the workpiece (26) during the processing. The first follower support rod (18) at the rear end is connected to the lower surface of the rear roller support plate (17) by bolts; the second follower support rod (19) at the rear end is connected to the groove of the first follower support rod (18) at the rear end; the follower support block (20) at the rear end is connected to the lower surface of the second follower support rod (19) at the rear end by bolts; the rear magnet (22) at the rear end is connected to the lower surface of the follower support block (20) at the rear end by bolts; the universal roller (21) at the rear end is connected to the follower support block (20) at the rear end by bolts. The lower surface of the support block (20); the thin-walled part (26) is clamped between the front universal roller (15) and the rear universal roller (21); the second electric cylinder (23) is connected to the rear roller support plate (17) by bolts, and the dome block (25) is connected to the top of the second electric cylinder shaft (24). Through the force sensor device (30), the first electric cylinder (5) and the second electric cylinder (23) can adjust the size of the air pressure during the grinding process, thereby reducing the deformation of the thin-walled part robot grinding position. The six-degree-of-freedom magnetorheological grinding posture fine-tuning mechanism (28) can adaptively adjust the posture of the grinding head according to the shape of the curved surface to ensure that the grinding head is tangent to the curved surface;

[0031] The force sensor device (30) is connected to the center of the lower surface of the front roller support plate (11), so that the data obtained by the force sensor device (30) is accurate; the pneumatic grinding device (27) is connected to the force sensor device (30) via an L-shaped plate (31).

[0032] like Figure 1 As shown, there are six magnetorheological dampers (8) which are symmetrically arranged between the upper fixing plate (1) and the lower fixing plate (10) to evenly bear the force transmitted from the lower fixing plate (10).

[0033] like Figure 5 As shown, the front second follower support rod (13) and the rear second follower support rod (19) are provided with slots, and screws are passed through the slots to constrain the movement direction of the support rods.

[0034] like Figure 5 As shown, the front universal roller (15) maintains a distance of about 1 mm from the front magnet (16) in the direction perpendicular to the contact surface of the workpiece, so that only the front universal roller (15) is in contact with the workpiece (26) during the processing.

[0035] like Figure 3 As shown, the six magnetorheological dampers (8) have a damping control function and can suppress the vibration of the workpiece and the spindle when the robot is grinding the workpiece.

[0036] like Figure 4 As shown, the follow-up variable stiffness support mechanism (29) is a force-controlled follow-up variable stiffness support mechanism, which can follow the movement of the grinding head, reduce the deformation of thin-walled parts during grinding, and improve the grinding accuracy.

[0037] The follow-up variable stiffness support mechanism (28) can clamp the grinding area of ​​the workpiece in real time during robot grinding, follow the movement of the robot grinding head, and continuously provide controllable air pressure to the other side of the grinding area, without providing a support fixture or auxiliary support robot that occupies a large space on the other side of the workpiece, thereby reducing the work area occupied, reducing the deformation of thin-walled parts during grinding, suppressing grinding vibration, and obtaining better grinding accuracy.

Claims

1. A six-degree-of-freedom robot conformal grinding device with a variable stiffness support, characterized in that: The invention comprises a six-degree-of-freedom magnetorheological grinding posture fine-tuning mechanism (28), a follow-up variable stiffness support mechanism (29), a pneumatic grinding device (27), and a force sensor device (30). The six-degree-of-freedom grinding posture fine-tuning mechanism (28) comprises: an upper fixing plate (1), a first joint ball bearing (2), a second joint ball bearing (3), an electric cylinder connecting block (4), a first electric cylinder (5), a first electric cylinder shaft (6), a universal joint (7), a magnetorheological damper (8), a connecting head (9), and a lower fixing plate (10). The universal joint (7) is connected to the lower surface of the upper fixed plate (1) by bolts; the first electric cylinder (5) is connected to the lower surface of the electric cylinder connecting block (4) by bolts; the upper surface of the electric cylinder connecting block (4) is provided with a first joint ball bearing (2); the end of the first electric cylinder shaft (6) is connected to the second joint ball bearing (3); the second joint ball bearing (3) is arranged at the center position of the upper surface of the lower fixed plate (10); the universal joint (7) is connected to the upper surface of the lower fixed plate (10) by bolts; the connector (9) is protrudingly connected to one end of the universal joint (7); the upper end of the magnetorheological damper (8) is connected to the universal joint (1) corresponding to the upper fixed plate (1), and the lower end is connected to the upper surface of the connector (9); The variable stiffness follower support mechanism (29) comprises: a front roller support plate (11), a front first follower support rod (12), a front second follower support rod (13), a front follower support block (14), a front universal roller (15), and a front magnet (16); a rear roller support plate (17), a rear first follower support rod (18), a rear second follower support rod (19), a rear follower support block (20), a rear universal roller (21), a rear magnet (22), a second electric cylinder (23), a second electric cylinder shaft (24), a dome block (25), a thin-walled member (26), and an L-shaped plate (31); the front first follower support rod (12) is connected to the lower surface of the front roller support plate (11) by bolts; the front second follower support rod (13) is connected to the groove of the front first follower support rod (12); the front follower support block (14) is connected to the lower surface of the front second follower support rod (13) by bolts; the front magnet ( 16) is connected to the lower surface of the front follower support block (14) by bolts; the front universal roller (15) is connected to the lower surface of the front follower support block (14) by bolts; the rear first follower support rod (18) is connected to the lower surface of the rear roller support plate (17) by bolts; the rear second follower support rod (19) is connected to the groove of the rear first follower support rod (18); the rear follower support block (20) is connected to the rear second follower support rod ( 19) lower surface; the rear end magnet (22) is connected to the lower surface of the rear end follower support block (20) by bolts; the rear end universal roller (21) is connected to the lower surface of the rear end follower support block (20) by bolts; the thin-walled member (26) is sandwiched between the front end universal roller (15) and the rear end universal roller (21); the second electric cylinder (23) is connected to the rear end roller support plate (17) by bolts, and the dome block (25) is connected to the top end of the second electric cylinder shaft (24); The force sensor device (30) is connected to the center of the lower surface of the front roller support plate (11); and the pneumatic grinding device (27) is connected to the force sensor device (30) via an L-shaped plate (31).

2. The six-degree-of-freedom robot conformal grinding device with a variable stiffness support according to claim 1, characterized in that: There are six magnetorheological dampers (8) which are circumferentially symmetrically arranged between the upper fixing plate (1) and the lower fixing plate (10).

3. The six-degree-of-freedom robot conformal grinding device with a variable stiffness support according to claim 1, characterized in that: The front second follower support rod (13) and the rear second follower support rod (19) are provided with slots.

4. The six-degree-of-freedom robot conformal grinding device with a variable stiffness support according to claim 1, characterized in that: The front universal roller (15) maintains a distance of about 1 mm from the front magnet (16) in a direction perpendicular to the contact surface of the workpiece, thereby achieving the purpose of only the front universal roller (15) being in contact with the workpiece (26) during the processing.

5. The six-degree-of-freedom robot conformal grinding device with a variable stiffness support according to claim 1, characterized in that: The front second follower support rod (13) and the rear second follower support rod (19) can move up and down along with the fluctuation of the shape of the workpiece (26) during the grinding process.

6. The six-degree-of-freedom robot conformal grinding device with a variable stiffness support according to claim 1, characterized in that: The pneumatic grinding device (27) and the force sensor device (30) as well as the axial center lines of the first electric cylinder (5) and the second electric cylinder (23) coincide with each other.

7. The six-degree-of-freedom robot conformal grinding device with a variable stiffness support according to claim 1, characterized in that: The six magnetorheological dampers (8) have a damping control function.

8. The six-degree-of-freedom robot conformal grinding device with a variable stiffness support according to claim 1, characterized in that: The follow-up variable rigidity support mechanism (29) is a force-controlled follow-up variable rigidity support mechanism, which can follow the movement of the grinding head, reduce the deformation of the thin-walled workpiece during grinding, and improve the grinding accuracy.

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