Force-sensing grinding and polishing device supporting revolution and rotation motion

Abstract

The invention discloses a force-sensing polishing device supporting revolution and autorotation, which comprises a revolution part and an autorotation part, a spoke type force measuring seat of the autorotation part is fixedly connected with an eccentric seat of the revolution part through a guide screw, and the eccentricity adjustment of the autorotation part can be realized; the small servo motor driving assembly comprises a small servo motor, a mounting seat and a small gear, and is fixed on the outer shaft body through the mounting seat; the pinion is matched with the bull gear to decelerate and drive the autorotation part to form revolution motion of the device; autorotation motion is directly driven by a servo motor through a coupling; strain gauges are attached to spokes of the spoke type force measuring base, and real-time sensing of normal force in the grinding and polishing process can be achieved; the conductive slip ring ensures stable transmission of electric signals of the rotation part in a rotation state. The device is compact in overall structure, has high-frequency and high-precision force sensing capacity, and is widely applied to the field of precision machining of complex free-form surfaces.

Description

Technical Field

[0001] The present invention relates to the technical field of precision machining equipment, and particularly relates to a force-sensing grinding and polishing device that supports revolution and rotation movements. Background Art

[0002] With the continuous progress of modern industrial manufacturing technology, especially in high-precision fields such as aerospace, energy power, and semiconductors, the processing demand for large and complex curved surface parts is increasing day by day. These parts usually have a high degree of geometric complexity, and the requirements for surface quality, geometric accuracy, and force control during the processing are becoming more and more stringent. Especially in the high-precision grinding and polishing process of optical surfaces, how to accurately control the contact force and relative movement between the workpiece and the tool has become a technical difficulty. Traditional manual operations are difficult to meet these requirements, and industrial robots have been widely used as an alternative for the processing of such parts. However, since the geometric shape of complex curved surfaces is usually difficult to obtain completely accurately, this results in the robot processing path often deviating from the target surface, and factors such as the relatively poor repeat positioning accuracy of the robot itself, the clamping error of the workpiece, and the non-linear change of the grinding and polishing force make it impossible to effectively guarantee the processing accuracy and quality by relying solely on the position accuracy of the industrial robot. Therefore, it is urgently necessary to endow the robot with the ability of force perception and force control during the grinding and polishing process.

[0003] Currently, force-position hybrid control devices are mainly divided into two types: cylinder-driven and motor-driven. Cylinder-driven force-position hybrid control devices, such as products developed by companies like Ferrobotics in Austria and PushCorp in the United States, have been applied in some fields, with high force control accuracy and relatively mature technology. However, cylinder-driven systems usually have significant non-linear problems, mainly reflected in the fact that it is difficult to accurately model the non-linear relationship between the pressure and load of the cylinder, resulting in a large limitation on its force control accuracy. In addition, the dynamic response speed of the cylinder-driven system is slow and has hysteresis, which makes it difficult to meet the requirements of high-efficiency force control in the grinding and polishing process with high-precision and fast-response demands.

[0004] Compared with cylinder-driven devices, motor-driven force-position hybrid control devices usually use voice coil motors with high response performance. Voice coil motors can achieve fast and accurate displacement control through direct drive, and are particularly suitable for precision force control applications that require high-frequency response. Although voice coil motors have relatively significant advantages in fast dynamic response, the influence of the load at the mover end on the motor's response ability cannot be ignored when the dynamic load changes. Under high-load conditions, the dynamic accuracy of voice coil motors will be greatly affected, resulting in a decline in force control performance. This problem is particularly prominent in the application of the robot end effector, because the change in the robot end pose will cause the gravity load of the force control device to vary with time, thus affecting the force control accuracy and stability.

[0005] In the above two types of force-position hybrid control devices, the force control of the polishing head and the position control of the robot are usually separated and independently controlled in different physical controllers. It is difficult for the robot controller to know the displacement deviation of the polishing head caused by force control. Without the help of additional sensors, it is also difficult for the polishing head to obtain the pose of the robot in real time. At the same time, traditionally, the robot polishing head generally only has the function of self-rotation and cannot meet the requirements of complex polishing processes. Therefore, a force-sensing polishing head that supports the combined motion of revolution and rotation and can be used for the unified control of the robot and the polishing head is needed. Summary of the Invention

[0006] Aiming at the problems of the existing robot end polishing device, such as single structure, insufficient force control accuracy, and poor trajectory adjustment ability, the present invention provides a high-precision force-sensing polishing device for robot polishing processing that supports revolution and rotation motions. Its purpose is to achieve high-precision polishing on the surfaces of complex curved surfaces, free curves, etc. by constructing a composite mechanism with trajectory regulation ability and force sensing function, thereby significantly improving the surface quality and profile accuracy.

[0007] To achieve the above object, the present invention provides a force-sensing polishing device that supports revolution and rotation motions, and the device includes a self-rotation part and a revolution part.

[0008] The self-rotation part of the present invention includes a servo motor, a motor base, a coupling, a spoke-type force-measuring seat, a spindle shaft body, an upper small bearing, a lower small bearing, a C-ring, a bearing gland, a mandrel, and a polishing disc. The servo motor is installed on the motor base. The motor base is fixedly connected to the spindle shaft body. The upper and lower ends of the spindle shaft body are provided with coaxial upper and lower small bearings for supporting the mandrel. The bearing gland and the C-ring are used for axial pressing and positioning of the upper and lower small bearings. The motor shaft of the servo motor is connected to the mandrel through a coupling. The polishing disc is installed at the end of the mandrel.

[0009] The self-rotation part of the present invention can realize the rotational motion of the polishing disc through the drive of the servo motor, and the rotational speed is continuously adjustable.

[0010] The revolution part of the present invention includes a small servo motor drive assembly, a large gear, an inner shaft body, an outer shaft body, an eccentric plate, a guide screw, an upper large bearing, a lower large bearing, and a conductive slip ring. The upper and lower ends of the outer shaft body are provided with upper and lower large bearings for supporting the inner shaft body to realize the coaxial rotational freedom between the inner shaft body and the outer shaft body. A set of small servo motor drive assemblies are respectively installed on both sides of the upper end of the outer shaft body. The fixed end of the conductive slip ring is installed at the lower end of the outer shaft body, and the rotating end of the conductive slip ring is fixedly connected to the inner shaft body. The large gear is fixed to the upper end of the inner shaft body, and the eccentric plate is fixedly connected to the upper end of the large gear through bolts.

[0011] The revolution part of the present invention is used to drive the rotational motion of the rotation part, and the rotational speed is continuously adjustable.

[0012] The rotation part of the present invention is fixed on the eccentric plate by a spoke-type force measuring seat using a guiding screw. By adjusting the position of the spoke-type force measuring seat on the eccentric plate guide rail, the eccentricity of the revolution motion can be changed to meet the requirements of the grinding and polishing process.

[0013] Furthermore, the spoke-type force measuring seat of the present invention adopts a resistance strain gauge type force measuring structure. Multiple strain gauges are evenly attached to the spoke area of the force measuring seat in a bridge or half-bridge arrangement, forming a high-sensitivity force measuring system capable of real-time sensing of minute force changes in the direction of the normal force, and having high resolution and linear response characteristics.

[0014] Furthermore, the mounting seat at the top of the outer shaft body of the present invention is used to reliably fix the device to the end flange interface of the robot, serving as the assembly basis for all motion and measurement and control components. The mounting seat has precisely machined positioning holes and circumferentially distributed screw holes, and cooperates with the large circular hole inside the mounting seat to achieve high-repeatability precision assembly docking;

[0015] Furthermore, the small servo motor drive assembly of the present invention includes a small servo motor, a mounting seat, and a small gear, and is fixed on the outer shaft body through the mounting seat. The small servo motor is fixed on the mounting seat, is directly connected to the small gear, and drives the motion of the small gear. The small gear meshes with the large gear of the rotation part to drive the entire rotation part at a reduced speed, and finally forms a composite motion trajectory of the revolution and rotation superposition of the grinding and polishing disc.

[0016] Furthermore, the slip ring of the present invention integrates multiple independent brushes and conductive ring channels, and can continuously supply power and transmit signals to components such as the servo motor of the rotation part and the strain gauges on the spoke-type force measuring seat under the compound rotation conditions of revolution and rotation, realizing multi-channel parallelism of power, control, and communication.

[0017] Furthermore, the servo motor of the present invention is an integrated direct drive type brushless servo motor, internally configured with a high-precision encoder, capable of real-time detecting the output shaft angle and rotational speed, and its signal constructs a closed-loop feedback system through the controller to precisely control the speed of the grinding and polishing disc and adapt to constructing a stable removal function.

[0018] Furthermore, the upper small bearing and lower small bearing of the rotation part of the present invention, as well as the upper large bearing and lower large bearing of the revolution part, are preferably crossed roller bearings or angular contact bearings, having high stiffness, anti-overturning moment ability, and excellent rotational precision. The bearing end cover is provided with a dust-proof seal and lubricating oil injection structure to extend the service life.

[0019] Generally speaking, through the technical solution proposed by the present invention, compared with the prior art, it mainly has the following technical advantages:

[0020] 1. The high-precision force-sensing lapping and polishing device provided by the present invention integrates the capabilities of revolution, rotation, and eccentric regulation, and can generate various removal function forms including the Gaussian removal function, significantly improving the adaptability of the lapping and polishing process.

[0021] 2. The spoke-type three-dimensional force-measuring seat adopted in the present invention has a hollow structure. Compared with the integrated force sensor solution of the integrator, the measuring surface can be closer to the lapping and polishing surface. While maintaining high sensitivity and wide range, it can improve the system rigidity at the lapping and polishing surface, realize real-time acquisition of tiny contact forces, form a force control closed-loop in combination with the robot controller, and ensure the stability of the pressure output during the processing.

[0022] 3. The present invention uses a high-precision conductive slip ring to provide continuous power supply and data link in the rotating state, providing stable power supply and signal feedback for the integrated motor, encoder, and sensor, and realizing systematic intelligent control.

[0023] 4. The structure in the present invention adopts a modular design, which is convenient for device disassembly, maintenance, and overall rapid replacement, and supports the deployment of industrial robot flexible manufacturing systems.

[0024] 5. The overall structure of the device of the present invention is compact and has high dynamic rigidity. It is suitable for lapping and polishing scenarios with small space, high precision, and complex curved surfaces, and has broad industrial application value. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 is the front view of the force-sensing lapping and polishing head supporting revolution and rotation movements of the present invention.

[0026] Figure 2 is Figure 1 the sectional view taken along the A-A direction of

[0027] Figure 3 is the sectional view of the small servo motor drive assembly of the lapping and polishing head.

[0028] Figure 4 is the top view of the lapping and polishing head.

[0029] Figure 5 is the three-dimensional projection schematic diagram of the lapping and polishing head.

[0030] In the figure: 1. Servo motor, 2. Coupling, 3. C-ring, 4. Spoke-type force-measuring seat, 5. Large gear, 6. Upper large bearing, 7. Inner shaft body, 8. Outer shaft body, 9. Conductive slip ring, 10. Lower large bearing, 11. Main shaft body, 12. Bearing gland, 13. Lapping and polishing disc, 14. Mandrel, 15. Lower small bearing, 16. Upper small bearing, 17. Small servo motor drive assembly, 18. Eccentric plate, 19. Guide screw, 20. Motor base, 21. Small servo motor, 22. Mounting seat, 23. Small gear. DETAILED DESCRIPTION OF THE INVENTION

[0031] In order to make the objectives, technical solutions and advantages of the present invention more clear and understandable, the present invention will be 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 used 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.

[0032] As Figures 1 to 5 shown, the present invention provides a force-sensing grinding and polishing device that supports revolution and rotation movements, including: a rotation part and a revolution part.

[0033] The rotation part of the present invention includes a servo motor 1, a motor base 20, a coupling 2, a spoke-type force measuring seat 4, a spindle shaft body 11, an upper small bearing 16, a lower small bearing 15, a C-ring 3, a bearing gland 12, a mandrel 14, and a grinding and polishing disc 13. By driving with a servo motor, the rotational movement of the grinding and polishing disc can be achieved, and the rotational speed is continuously adjustable.

[0034] The revolution part of the present invention includes a small servo motor drive assembly, a large gear 5, an inner shaft body 7, an outer shaft body 8, an eccentric plate 18, a guiding screw 19, an upper large bearing 6, a lower large bearing 10, and a conductive slip ring 9. The revolution part is used to drive the rotational movement of the rotation part, and the rotational speed is continuously adjustable.

[0035] The rotation part of the present invention is fixed on the eccentric plate 18 by the spoke-type force measuring seat 4 using the guiding screw 19. By adjusting the position of the spoke-type force measuring seat 4 on the eccentric plate guide rail, the eccentricity of the revolution movement can be changed to meet the requirements of the grinding and polishing process.

[0036] The servo motor of the present invention is installed on the motor base 20. The motor base 20 is fixedly connected to the spindle shaft body 11. The upper and lower ends of the spindle shaft body 11 are equipped with coaxial upper small bearing 16 and lower small bearing 15 for supporting the mandrel 14. The bearing gland 12 and the C-ring 3 are used for axial compression positioning of the upper small bearing 16 and the lower small bearing 15. The motor shaft of the servo motor 1 is connected to the mandrel 14 through the coupling 2. The grinding and polishing disc 13 is installed at the end of the mandrel 14.

[0037] The spoke-type force measuring seat 4 of the present invention adopts a resistance strain gauge type force measuring structure. A plurality of strain gauges are evenly attached to the spoke area of the force measuring seat in a bridge or half-bridge arrangement, forming a high-sensitivity force measuring system that can sense minute force changes in the direction of the normal force in real time, and has high resolution and linear response characteristics.

[0038] At both ends of the outer shaft body 8 of the present invention, upper large bearings 6 are installed. The lower large bearing 6 is used to support the inner shaft body 7, realizing the coaxial rotational freedom between the inner shaft body 7 and the outer shaft body 8. On both sides of the upper end of the outer shaft body 8, a set of small servo motor drive assemblies are installed respectively. At the lower end of the outer shaft body 8, the fixed end of a conductive slip ring 9 is installed, and the rotating end of the conductive slip ring 9 is fixedly connected to the inner shaft body 7. At the upper end of the inner shaft body 7, a large gear 5 is fixed, and an eccentric plate 18 is fixed to the upper end of the large gear 5 by bolt connection.

[0039] The mounting seat 22 at the top of the outer shaft body 8 of the present invention is used to reliably fix the device to the flange interface at the end of the robot, serving as the assembly basis for all motion and measurement and control components. The mounting seat 22 has precisely machined positioning holes and circumferentially distributed screw holes, and together with the large circular hole inside the mounting seat 22, it realizes the assembly docking with high repeatability accuracy.

[0040] Figure 3 It is a cross-sectional view of the small servo motor drive assembly for the polishing head, as Figure 4 shown. The small servo motor drive assembly 17 of the present invention includes a small servo motor 21, a mounting seat 22, and a small gear 23, which is fixed on the outer shaft body 8 through the mounting seat 22. The small servo motor 21 is fixed on the mounting seat 22, directly connected to the small gear 23, and drives the movement of the small gear 23. The small gear 23 meshes with the large gear 5 of the rotation part, driving the entire rotation part at a reduced speed, and finally forming a composite motion trajectory of the superposition of the revolution and rotation of the polishing disc.

[0041] The conductive slip ring of the present invention integrates multiple independent brushes and conductive ring channels, and can continuously supply power and transmit signals to components such as the servo motor of the rotation part and the strain gauges on the spoke type force measuring seat under the compound rotation conditions of revolution and rotation, realizing the multi-channel parallel operation of power, control, and communication.

[0042] The servo motor of the present invention is an integrated direct drive brushless servo motor, internally configured with a high-precision encoder, which can real-time detect the angle and speed of the output shaft. Its signal constructs a closed-loop feedback system through the controller to precisely control the speed of the polishing disc and adapt to the construction of a stable removal function.

[0043] The upper small bearing 16 and lower small bearing 15 of the rotation part of the present invention, as well as the upper large bearing 6 and lower large bearing 10 of the revolution part, are preferably crossed roller bearings or angular contact bearings, with high stiffness, anti-overturning moment ability, and excellent rotation accuracy. The bearing end covers are provided with dust-proof seals and lubricating oil injection structures to extend the service life.

[0044] Figure 1 It is the front view of the force-sensing polishing head that supports the revolution and rotation movements of the present invention, showing the overall appearance and main structure on the front of the polishing head, reflecting its dimensions and component layout in the length and height directions.

[0045] Figure 2 This is a cross-sectional view of the grinding and polishing head. By cutting the grinding and polishing head, the assembly relationship of the internal components is clearly presented, including the specific positions and mutual connection methods of key components such as motors and transmission components.

[0046] Figure 4 This is a top view of the polishing head, which shows the contour shape of the polishing head on the horizontal plane, the distribution of components, and the plane size relationship of each part from a vertical perspective above.

[0047] Figure 5 This is a projected 3D diagram of the polishing head, showcasing its overall appearance in an intuitive, three-dimensional format. The spatial position and general shape of each component of the polishing head can be clearly seen, including the motor structure at the top, the auxiliary devices on both sides, and the main base at the bottom, helping to understand the overall spatial structure of the polishing head and the relative positions of its components.

[0048] The following combination Figure 2 The working principle of the device structure of the present invention is further explained: when the robot end drives the device to operate, the small servo motor of the revolving part drives the small gear to rotate, and through the engagement with the large gear, drives the inner shaft and the rotating part to complete the revolving motion around the axis of the outer shaft; at the same time, the servo motor of the rotating part drives the spindle and drives the polishing disk to rotate around its own center. Under the superposition of revolution and rotation, a spiral or cycloid-like trajectory is formed to meet different removal functions and residence time requirements.

[0049] During operation, strain gauges in the spoke-type force mount sense the normal contact force between the polishing disc and the workpiece surface in real time, feeding it back to the control system. Based on the deviation between the feedback force and the set target force, the system adjusts the robot's position increments to achieve force-controlled constant pressure, effectively ensuring surface quality.

[0050] The grinding and polishing device described in the present invention is particularly suitable for automated grinding and polishing of metal, ceramic, glass and other parts with high requirements for high finish, complex morphology and curved surface profile, and is widely used in aerospace, precision molds, optical mirrors, semiconductor equipment and other fields.

[0051] It should be noted that those skilled in the art may make equivalent improvements or adjustments to the structure, connection mode, control logic, etc. of the device without departing from the concept of the present invention, and all of these should fall within the scope of protection of the present invention.

Claims

1. A force-sensing grinding and polishing device that supports revolution and rotation movements, characterized in that It consists of two parts: revolution and rotation, which work together. The rotating part includes a servo motor, a motor base, a coupling, a spoke-type dynamometer base, a spindle shaft, an upper small bearing, a lower small bearing, a C-shaped ring, a bearing cover, a spindle, and a grinding and polishing disc; the servo motor is mounted on the motor base; the motor base is fixedly connected to the spindle shaft; the upper small bearing and the lower small bearing are coaxially mounted at the upper and lower ends of the spindle shaft to support the spindle; the bearing cover and the C-shaped ring are used for axial compression and positioning of the upper and lower small bearings; the motor shaft of the servo motor is connected to the spindle through a coupling; the grinding and polishing disc is mounted at the end of the spindle; the grinding and polishing disc is driven by the servo motor to realize the rotational motion of the grinding and polishing disc, and the speed is continuously adjustable; The revolution part includes a small servo motor drive assembly, a large gear, an inner shaft, an outer shaft, an eccentric plate, a lead screw, an upper large bearing, a lower large bearing and a conductive slip ring; the upper large bearing and the lower large bearing are installed at both ends of the outer shaft to support the inner shaft and realize the coaxial rotation freedom between the inner shaft and the outer shaft; a set of small servo motor drive assemblies are installed on both sides of the upper end of the outer shaft; the fixed end of the conductive slip ring is installed at the lower end of the outer shaft, and the rotating end of the conductive slip ring is fixed to the inner shaft; the large gear is fixed at the upper end of the inner shaft, and the eccentric plate is fixed to the upper end of the large gear through bolts; the revolution part is used to drive the rotational motion of the rotation part, and the speed is continuously adjustable.

2. The force-sensing grinding and polishing device supporting revolution and rotation movement according to claim 1, wherein: The spoke-type force measuring seat adopts a resistance strain gauge force measuring structure. Multiple strain gauges are evenly attached to the spoke area of the force measuring seat in a bridge or half-bridge arrangement, forming a highly sensitive force measuring system that can sense tiny force changes in the normal force direction in real time, with high resolution and linear response characteristics.

3. The force-sensing grinding and polishing device supporting revolution and rotation movement according to claim 1, characterized in that: The mounting base at the top of the outer shaft is used to securely fix the device to the flange interface at the end of the robot. As the assembly basis for all motion and measurement and control components, the mounting base has precisely machined positioning holes and circumferentially distributed screw holes, which, together with the large circular hole inside the mounting base, achieve assembly and docking with high repeatability and precision.

4. The force-sensing grinding and polishing device supporting revolution and rotation movements according to claim 1, characterized in that: The small servo motor drive assembly includes a small servo motor, a mounting base, and a small gear, which is fixed to the outer shaft through the mounting base; the small servo motor is fixed to the mounting base, directly connected to the small gear, and drives the movement of the small gear; the small gear engages with the large gear of the rotating part, reduces speed and drives the entire rotating part, and finally forms a composite motion trajectory in which the revolution and rotation of the polishing disc are superimposed.

5. The force-sensing grinding and polishing device supporting revolution and rotation movement according to claim 1, wherein: The conductive slip ring integrates multiple independent brushes and conductive ring channels. Under the combined rotation conditions of revolution and rotation, it continuously supplies power and transmits signals to the servo motor of the rotating part and the strain gauge on the spoke-type force measuring seat, realizing multi-channel parallel operation of power, control and communication.

6. The force-sensing grinding and polishing device supporting revolution and rotation movement according to claim 1, wherein: The servo motor is an integrated direct-drive brushless servo motor with an internal high-precision encoder to detect the output shaft angle and speed in real time. The signal is passed through the controller to build a closed-loop feedback system to precisely control the grinding and polishing disc speed.

7. The force-sensing grinding and polishing device supporting revolution and rotation movements according to claim 1, characterized in that: The small upper bearing and the small lower bearing of the rotating part and the large upper bearing and the large lower bearing of the revolving part are cross roller bearings or angular contact bearings, and the bearing end covers are provided with dustproof seals and lubrication oil injection structures.

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