Single-degree-of-freedom constant-force polishing and grinding device

Abstract

The invention relates to the field of polishing and grinding equipment, in particular to a single-degree-of-freedom constant-force polishing and grinding device which comprises a main support, a rotating motor is installed above the main support, a voice coil motor is installed on the bottom face of the main support, the output end of the rotating motor is coaxially connected with a spline shaft, and the spline shaft sequentially penetrates through the main support and the voice coil motor to be arranged. The lower portion of the spline shaft is sleeved with a spline sleeve, the spline sleeve slides in the axial direction relative to the spline shaft and is fixed in the circumferential direction, the spline sleeve is fixed in the axial direction relative to the output end of the voice coil motor and rotates in the circumferential direction, and a polishing and grinding head is installed on the lower portion of the spline sleeve. The polishing and grinding device is composed of main shaft rotating motion driven by the rotating motor and linear displacement motion driven by the voice coil motor along the main shaft, and has the advantages of being simple in control mode, high in response speed, high in displacement control precision and the like.

Description

Technical Field

[0001] The present invention relates to the field of polishing equipment, and specifically to a single-degree-of-freedom constant-force polishing device. Background Art

[0002] Existing polishing tools are mainly angle grinders, which use high-speed rotating thin grinding wheels, rubber grinding wheels, wire wheels and other processing tools to grind, cut and polish workpieces such as metals or stones. During the grinding and polishing operation, the processing tools are worn as they are used, resulting in surface position errors, causing changes in the contact force, and thus affecting the processing effect. Constant-force floating polishing is one form of polishing tools, which can achieve constant-force contact between the processing tool and the workpiece. However, during constant-force floating polishing, the polishing tool is prone to vibration, thus affecting the force control accuracy. How to quickly respond to vibration and achieve high-precision displacement control to realize high-precision operation is of great significance. Summary of the Invention

[0003] The purpose of the present invention is to provide a single-degree-of-freedom constant-force polishing device to solve the problems raised in the above background art.

[0004] To achieve the above purpose, the present invention provides the following technical solution: A single-degree-of-freedom constant-force polishing device, including a main bracket, a rotary motor is installed above the main bracket, a voice coil motor is installed on the bottom surface of the main bracket, the voice coil motor has an axial hole, the output end of the rotary motor is coaxially connected with a spline shaft, the spline shaft sequentially passes through the main bracket and the axial hole of the voice coil motor, a spline sleeve is sleeved on the lower part of the spline shaft, the spline sleeve axially slides relative to the spline shaft and is circumferentially fixed, and the spline sleeve is axially fixed and circumferentially rotatable relative to the output end of the voice coil motor, and a polishing head is installed on the lower part of the spline sleeve.

[0005] Optionally, it further includes a six-axis force sensor arranged between the main bracket and the flange at the end of the robotic arm. A main bracket side plate is provided on one side of the main bracket, an I-shaped adapter bracket is connected to the opposite side of the flange at the end of the robotic arm, the six-axis force sensor is installed between the adapter bracket and the main bracket side plate, the six-axis force sensor is electrically connected to a microcontroller, and the microcontroller is electrically connected to the rotary motor and the voice coil motor.

[0006] Optionally, a motor mounting seat is provided on the top surface of the main bracket, and the rotary motor is installed on the motor mounting seat.

[0007] Optionally, the spline shaft is a ball spline shaft, and the spline sleeve is a ball spline nut; a first bearing is installed between the upper part of the spline shaft and the main bracket.

[0008] Optionally, a lower connecting plate is provided below the main bracket. The output end of the voice coil motor is connected to the lower connecting plate. A bearing connecting member is connected to the bottom surface of the lower connecting plate. A ball spline coupling cylinder is fixedly sleeved on the spline sleeve. A second bearing is installed between the ball spline coupling cylinder and the bearing connecting member.

[0009] Optionally, a connecting shaft is connected to the lower end of the ball spline coupling cylinder. A tool holder assembly is connected to the lower end of the connecting shaft. The polishing head is installed at the lower end of the tool holder assembly.

[0010] Optionally, a displacement sensor is installed on the lower connecting plate; a plurality of linear bearing seats are installed along the circumference of the bottom surface of the main bracket. A linear guide shaft is provided in the linear bearing seat. The lower end of the linear guide shaft is connected to the lower connecting plate.

[0011] Optionally, the displacement sensor includes a cooperating magnetic grating scale and a magnetic grating reader head. A magnetic grating scale mounting plate is installed on the lower connecting plate. A magnetic grating scale is provided on the magnetic grating scale mounting plate. A magnetic grating reader head adjustment plate is installed on the bottom surface of the main bracket. A magnetic grating reader head is provided on the magnetic grating reader head adjustment plate. The magnetic grating reader head is electrically connected to the microcontroller.

[0012] Compared with the prior art, the present invention has the following beneficial effects: 1. The polishing device of the present invention consists of the rotational movement of the main shaft driven by a rotary motor and the linear displacement movement along the main shaft driven by a voice coil motor. The torque transmission is realized by the axial sliding and circumferential fixation of the spline sleeve and the spline shaft. The constant force floating control is realized by the axial fixation and circumferential rotation of the spline sleeve and the output end of the voice coil motor. It has the advantages of simple control method, fast response speed, and high displacement control accuracy. 2. The present invention installs a six-axis force sensor between the polishing device and the end flange of the robotic arm to obtain the contact force information at the end of the polishing head; a magnetic grating absolute displacement sensor is used to real-time detect the absolute linear displacement of the output end of the voice coil motor, and it can retain the position information without having to re-zero after power-off, which has the advantages of high reliability and high precision.

[0013] 3. The present invention adopts a ball spline shaft and a ball spline nut, which has the advantages of small friction, high efficiency, and smooth movement, and allows the polishing head to achieve high-speed and high-precision axial linear motion control with low energy consumption under load. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 is a schematic structural diagram of the present invention; Figure 2 is a half-sectional schematic diagram of the present invention.

[0015] In the figure: 1. Flange at the end of the robotic arm; 2. Adapter bracket; 3. Six-axis force sensor; 4. Main bracket; 401. Side plate of the main bracket; 5. Motor mounting base; 6. Rotary motor; 7. Voice coil motor; 701. Stator of the voice coil motor; 702. Moving coil of the voice coil motor; 8. Displacement sensor; 801. Adjusting plate for the magnetic head; 802. Magnetic head; 803. Mounting plate for the magnetic scale; 804. Magnetic scale; 9. Linear bearing housing; 10. Linear guide shaft; 11. Lower connecting plate; 12. Bearing connector; 13. Spline shaft; 14. Spline sleeve; 15. Ball spline coupling cylinder; 16. First bearing; 17. Second bearing; 18. Connecting shaft; 19. Tool sleeve assembly; 20. Polishing head. Detailed implementation manners

[0016] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0017] Please refer to Figure 1 and Figure 2As shown in the figure, this embodiment provides a single-degree-of-freedom constant-force polishing device, which includes a main bracket 4. A main bracket side plate 401 is provided on the left side of the main bracket 4. The main bracket side plate 401 and the main bracket 4 are combined to form a T-shaped structure, and the main bracket side plate 401 is used to connect with the flange at the end of the robotic arm 1. Specifically, an I-shaped adapter bracket 2 is connected to the right side of the flange at the end of the robotic arm 1. A six-axis force sensor 3 is installed between the adapter bracket 2 and the main bracket side plate 401. In this embodiment, the six-axis force sensor of the Yuli brand M3813D is selected. The six-axis force sensor 3 is electrically connected to a microcontroller to collect and transmit the force data received at the end of the robotic arm to the microcontroller. A motor mounting seat 5 is fixedly connected to the top surface of the main bracket 4. A rotary motor 6 is installed on the motor mounting seat 5. The rotary motor 6 uses a servo motor. A voice coil motor 7 with an axial hole is installed on the bottom surface of the main bracket 4. The voice coil motor 7 includes a voice coil motor stator 701 and a voice coil motor moving coil 702. The voice coil motor stator 701 is fixedly connected to the bottom surface of the main bracket 4. The voice coil motor moving coil 702 is arranged downward and fixedly connected to a lower connecting plate 11. A bearing connecting piece 12 is fixedly connected to the bottom surface of the lower connecting plate 11. The output end of the rotary motor 6 is coaxially connected to a spline shaft 13 through a coupling. The spline shaft 13 sequentially passes through the main bracket 4, the axial hole of the voice coil motor 7, and the lower connecting plate 11. A spline sleeve 14 is sleeved on the lower part of the spline shaft 13. The spline sleeve 14 is axially slidable and circumferentially fixed relative to the spline shaft 13 to transmit torque and perform floating constant-force adjustment. A ball spline connecting cylinder 15 is fixedly sleeved on the lower part of the spline sleeve 14. The length of the ball spline connecting cylinder 15 is longer than that of the spline sleeve 14 to extend the axial length of the spline sleeve 14, that is, to continue to transmit rotational motion outward while not hindering the axial movement of the spline shaft 13. A second bearing 17 is installed between the ball spline connecting cylinder 15 and the bearing connecting piece 12 to axially control the position of the spline sleeve 14 under the condition that the voice coil motor 7 is not rotated by the spline sleeve 14. The lower end of the ball spline connecting cylinder 15 is connected to a connecting shaft 18. The lower end of the connecting shaft 18 is connected to a tool holder assembly 19. A polishing head 20 is installed at the lower end of the tool holder assembly 19.

[0018] It should be noted that the spline shaft 13 is preferably a ball spline shaft, and the spline sleeve 14 is preferably a ball spline nut. Compared with the traditional sliding spline, the ball spline has the advantages of small friction, high efficiency, and smooth movement. This design allows for high-speed and high-precision linear motion with low energy consumption under load. At the same time, the above-mentioned second bearing 17 is selected as a double-row angular contact ball bearing. To improve the stability of the axial transmission of the spline shaft 13, a first bearing 16 is installed between the upper part of the spline shaft 13 and the main bracket 4. The first bearing 16 is selected as a deep groove ball bearing.

[0019] On the basis of the above embodiments, a displacement sensor 8 is installed on the lower connecting plate 11. Three linear bearing seats 9 are fixedly connected to the bottom surface of the main bracket 4 along the circumferential direction. A linear guide shaft 10 is slidably arranged in the linear bearing seat 9, and the lower end of the linear guide shaft 10 is connected to the lower connecting plate 11. The displacement sensor 8 is used to detect the absolute linear displacement of the output end of the voice coil motor 7 in real time, that is, the absolute linear displacement of the voice coil motor moving coil 702. The linear guide shaft 10 is used for the linear guidance of the vertical movement of the lower connecting plate 11 and increases the structural rigidity at the same time.

[0020] On the basis of the above embodiments, the displacement sensor 8 in this embodiment selects a magnetic grating scale 804 and a magnetic grating head 802 used in cooperation. An L-shaped magnetic grating scale mounting plate 803 is installed on the lower connecting plate 11, and a magnetic grating scale 804 is arranged on the magnetic grating scale mounting plate 803. An L-shaped magnetic grating head adjustment plate 801 is installed on the bottom surface of the main bracket 4, and a magnetic grating head 802 is installed on the magnetic grating head adjustment plate 801. The magnetic grating head 802 is electrically connected to the microcontroller. The microcontroller is electrically connected to the voice coil motor 7 through a TMZP series driver, and at the same time, the microcontroller is electrically connected to the rotary motor 6 through a servo motor driver. In this embodiment, the current of the voice coil motor 7 is adjusted in real time based on the absolute displacement information obtained by the magnetic grating head 802 and the force information obtained by the six-axis force sensor 3, so as to realize the acceleration, deceleration, and stop control of the movement of the voice coil motor moving coil 702. The control method is relatively simple, and the rotational motion control and the linear motion control are separately controlled, which is convenient for control.

[0021] Although the embodiments of the present invention have been shown and described, it will be understood by those of ordinary skill in the art that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of the present invention. The scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A single-degree-of-freedom constant-force polishing device, comprising a main support (4), a rotating motor (6) being installed above the main support (4), characterized in that: A voice coil motor (7) is installed on the bottom surface of the main bracket (4), and the voice coil motor (7) has an axial center hole. The output end of the rotating motor (6) is coaxially connected with a spline shaft (13), and the spline shaft (13) passes through the axial center holes of the main bracket (4) and the voice coil motor (7) in sequence. A spline sleeve (14) is sleeved on the lower part of the spline shaft (13), and the spline sleeve (14) is axially slidable and circumferentially fixed relative to the spline shaft (13), and the spline sleeve (14) is axially fixed and circumferentially rotated relative to the output end of the voice coil motor (7), and a polishing head (20) is installed on the lower part of the spline sleeve (14).

2. A single-degree-of-freedom constant-force polishing device according to claim 1, characterized in that: The invention also comprises a six-dimensional force sensor (3) arranged between a main support (4) and a flange (1) at the end of the robot arm, wherein a main support side plate (401) is arranged on one side of the main support (4), and an I-shaped adapter support (2) is connected to the opposite side of the flange (1) at the end of the robot arm, and the six-dimensional force sensor (3) is installed between the adapter support (2) and the side plate (401) of the main support, and the six-dimensional force sensor (3) is electrically connected to a microcontroller, and the microcontroller is electrically connected to a rotating motor (6) and a voice coil motor (7).

3. A single-degree-of-freedom constant-force polishing device according to claim 1, characterized in that: A motor mounting seat (5) is provided on the top surface of the main bracket (4), and the rotating motor (6) is mounted on the motor mounting seat (5).

4. A single-degree-of-freedom constant-force polishing device according to claim 1, characterized in that: The spline shaft (13) is a ball spline shaft, and the spline sleeve (14) is a ball spline nut; a first bearing (16) is installed between the upper part of the spline shaft (13) and the main bracket (4).

5. A single-degree-of-freedom constant-force polishing device according to claim 2, characterized in that: A lower end connecting plate (11) is arranged below the main bracket (4), the output end of the voice coil motor (7) is connected to the lower end connecting plate (11), the bottom surface of the lower end connecting plate (11) is connected to a bearing connecting piece (12), a ball spline connecting tube (15) is fixedly sleeved on the spline sleeve (14), and a second bearing (17) is installed between the ball spline connecting tube (15) and the bearing connecting piece (12).

6. A single-degree-of-freedom constant-force polishing device according to claim 5, characterized in that: The lower end of the ball spline connection cylinder (15) is connected to a connecting shaft (18), the lower end of the connecting shaft (18) is connected to a tool sleeve assembly (19), and the lower end of the tool sleeve assembly (19) is equipped with the polishing head (20).

7. A single-degree-of-freedom constant-force polishing device according to claim 5, characterized in that: A displacement sensor (8) is installed on the lower end connecting plate (11); a plurality of linear bearing seats (9) are installed on the bottom surface of the main bracket (4) along the circumferential direction, a linear guide shaft (10) is arranged inside the linear bearing seat (9), and the lower end of the linear guide shaft (10) is connected to the lower end connecting plate (11).

8. A single-degree-of-freedom constant-force polishing device according to claim 7, characterized in that: The displacement sensor (8) comprises a magnetic scale (804) and a magnetic scale reader (802) which cooperate with each other; a magnetic scale mounting plate (803) is mounted on the lower end connecting plate (11); a magnetic scale (804) is arranged on the magnetic scale mounting plate (803); a magnetic scale reader adjustment plate (801) is mounted on the bottom surface of the main bracket (4); a magnetic scale reader (802) is arranged on the magnetic scale reader adjustment plate (801); and the magnetic scale reader (802) is electrically connected to the microcontroller.

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