A precision polishing grinding head with controllable deformation in different zones

Abstract

The application discloses a precision polishing grinding head with controllable deformation in subareas, and belongs to the technical field of precision machining equipment. The precision polishing grinding head comprises a subarea base, a positioning block is arranged at the center below the subarea base, and no less than one set of connecting rod assemblies are arranged above the subarea base. A curvature adjusting head is connected to the top end of the connecting rod assemblies. A flexible polishing head is arranged above the curvature adjusting head. A protective shell is arranged outside the connecting rod assemblies. The flexible polishing head and the protective shell are connected through a grinding head frame. The device is provided with a driving circuit. The precision polishing grinding head with controllable deformation in subareas is used to control the curvature radius of the center and the edge of the flexible polishing head through the subarea base and independent shape memory alloy drivers, to optimize the edge pressure, bring stable contact stiffness and uniform pressure distribution, and realize more precise surface shape control. The shape memory alloy driver is a solid element, and can realize the required driving force and displacement in a relatively compact space by cooperating with a transverse amplification connecting rod.

Description

Technical Field

[0001] The invention relates to the technical field of precision machining equipment, in particular to a partitionable and controllably deformable precision polishing grinding head. Background Art

[0002] With the rapid development of modern optical manufacturing technology, optical components and mechanical parts are increasingly used in aerospace, defense, astronomical observation, laser systems, and other fields. Major national projects such as large astronomical telescopes, high-energy laser systems, and advanced military optical systems place stringent demands on the machining accuracy and surface quality of optical components and mechanical parts.

[0003] Polishing is a core process in the precision machining of optical components and mechanical parts. Its accuracy directly impacts the component's surface accuracy, surface roughness, and overall performance. In optical component machining, polishing determines the imaging quality and stability of the optical system; in mechanical component machining, polishing influences the wear resistance, corrosion resistance, and assembly accuracy of the part. Among numerous polishing techniques, computer-controlled polishing with small grinding heads has become a mainstream method in modern ultra-precision manufacturing due to its high controllability, flexibility, and process repeatability. During the polishing process, the radius of curvature of the grinding head is a key parameter affecting the polishing result, directly influencing the surface accuracy, surface roughness, and material removal efficiency. When machining workpiece edges with a fixed curvature grinding head, the increased contact linear velocity gradient can easily lead to over-removal. Furthermore, curvature mismatch reduces contact stiffness, easily inducing high-frequency chatter and worsening surface waviness. These issues not only impact the imaging quality of optical components, but also the surface quality and service life of mechanical parts. Therefore, the development of a polishing head with zoned and controllable deformation offers an ideal solution to these challenges. Summary of the Invention

[0004] The purpose of the present invention is to provide a precision polishing grinding head with partitionable and controllable deformation. Through a partitioned base and an independent shape memory alloy driver array, the curvature radius of the center and edge of the flexible polishing head can be independently controlled, the edge pressure distribution can be optimized, and a more stable contact stiffness and a more uniform pressure distribution can be achieved. The problem of excessive or insufficient edge removal caused by factors such as linear speed changes can be suppressed or compensated, the surface accuracy of the workpiece edge can be improved, and more precise and localized surface control can be achieved.

[0005] To achieve the above-mentioned objectives, the present invention provides a precision polishing grinding head with partitionable and controllable deformation, comprising a partition base, a positioning block is provided in the center below the partition base, and at least one group of connecting rod assemblies are provided above the partition base, the connecting rod assembly includes a shape memory alloy driver, a curvature adjustment head is connected to the top of the connecting rod assembly, a flexible polishing head is provided above the curvature adjustment head, a protective shell is provided on the outside of the connecting rod assembly, the flexible polishing head and the protective shell are connected through a grinding head frame, and the device as a whole is provided with a driving circuit, which controls the shape memory alloy driver to achieve partitioned and controllable deformation of the flexible polishing head.

[0006] Preferably, the partition base is provided with at least one partition unit, the partition units are evenly distributed on the surface of the partition base, the connecting rod assembly corresponds to the number and position of the partition units, and the connecting rod assembly is used to independently control the partitions of the flexible polishing head.

[0007] Preferably, the connecting rod assembly includes a base, which is connected to the partition base by bolts, and a fork rod and a driver support rod are arranged parallel to the top of the base, and the top of the driver support rod is connected to the shape memory alloy driver, and the shape memory alloy driver and the fork rod are movably connected through a transverse amplification connecting rod, and the tail end of the transverse amplification connecting rod is hinged to a first connecting rod, and the first connecting rod is hinged to a second connecting rod, and the second connecting rod is connected to the curvature adjustment head, and the second connecting rod is used to transmit the displacement of the shape memory alloy driver to the curvature adjustment head.

[0008] Preferably, the shape memory alloy driver is connected to the head end of the transverse amplification link, and the fork rod is connected to the middle section of the transverse amplification link.

[0009] Preferably, the outer contour of the curvature adjusting head is hemispherical, and the curvature adjusting head is provided with a gap, and the gap structure is used to generate controllable deformation when the curvature adjusting head is subjected to force.

[0010] Preferably, the flexible polishing head is in direct contact with the curvature adjusting head, and the flexible polishing head adjusts the curvature radius of the working surface through the curvature adjusting head.

[0011] Preferably, the driving circuit includes a main control system, which receives signal inputs from a processing path storage unit and a workpiece morphology measurement module, and the main control system inputs a control quantity to a shape memory alloy driver control module, and the shape memory alloy driver control module drives the connecting rod assembly to move and amplifies the displacement acting on the curvature adjustment head, and the curvature adjustment head controls the flexible polishing head to produce deformation and be used for workpiece processing, and the driving circuit is provided with a power supply module.

[0012] Therefore, the present invention adopts the above-mentioned partitionable and controllable deformation precision polishing grinding head, which has the following beneficial effects:

[0013] 1) Achieved "zone-controlled" deformation of the polishing head curvature: Traditional fixed-curvature grinding heads have curvature mismatch problems when polishing complex surfaces, especially edge areas, resulting in uneven contact stress and easily causing defects such as excessive edge removal, medium- and high-frequency surface errors and scratches. Some existing deformable grinding heads can only achieve uniform adjustment of the overall curvature and cannot specifically address the different polishing requirements of the center and edge areas.

[0014] Through flexible deformation and curvature adjustment, the present invention can match the local curvature of the workpiece in real time and significantly improve the contact state; through the partitioned base and independent shape memory alloy driver array, the curvature radius of the center and edge of the flexible polishing head can be independently controlled, the edge pressure distribution is optimized, and more stable contact stiffness and more uniform pressure distribution are brought about. It can suppress or compensate for the problem of excessive or insufficient edge removal caused by factors such as linear speed changes, improve the surface accuracy of the workpiece edge, and achieve more precise and localized surface control.

[0015] 2) Solid-state drive is adopted, and the structure is relatively compact: The shape memory alloy drive is a solid-state drive element, and combined with the lateral amplification connecting rod, it can achieve the required driving force and displacement in a relatively compact space, and is easy to integrate into existing polishing equipment or robotic systems.

[0016] 3) The present invention can be applied to the precision polishing of various complex curved surfaces, and is particularly suitable for the processing of high-precision optical elements, aerospace parts, precision medical equipment and other fields, and can significantly improve the surface quality and surface accuracy.

[0017] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 This is a schematic diagram of the internal structure of an embodiment of a precision polishing grinding head with partitionable and controllable deformation according to the present invention;

[0019] Figure 2 This is an appearance diagram of an embodiment of a precision polishing grinding head with partitionable and controllable deformation according to the present invention;

[0020] Figure 3 This is a structural diagram of a connecting rod assembly of an embodiment of a precision polishing grinding head with partitionable and controllable deformation according to the present invention;

[0021] Figure 4 This is a structural diagram of a curvature adjustment head of an embodiment of a precision polishing grinding head with partitionable and controllable deformation according to the present invention;

[0022] Figure 5is a center area curvature radius adjusting principle diagram of an embodiment of the precision polishing grinding head of the application;

[0023] Figure 6 is an edge area curvature radius adjusting principle diagram of an embodiment of the precision polishing grinding head of the application;

[0024] Figure 7 is a driving circuit control principle diagram of an embodiment of the precision polishing grinding head of the application.

[0025] Reference signs

[0026] 1, partition base; 2, positioning block; 3, connecting rod assembly; 31, base; 32, bolt; 33, fork rod; 34, driver support rod; 35, shape memory alloy driver; 36, transverse amplification connecting rod; 37, first connecting rod; 38, second connecting rod; 4, curvature adjusting head; 5, grinding head frame; 6, flexible polishing head; 7, protective shell. DETAILED DESCRIPTION

[0027] The technical solutions of the application are further described below by means of the accompanying drawings and embodiments.

[0028] Unless otherwise defined, technical or scientific terms used in the present application shall have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. Unless otherwise defined, the terms "first", "second", and the like, used in the present application do not necessarily have any order or sequence, and are used to distinguish different components. The terms "comprise", "comprising", "include", "including", and the like, mean encompassing, containing, or providing, and the like, the elements or objects listed after such terms, and equivalents thereof, and do not exclude other elements or objects. The terms "connect", "connected", and the like, do not necessarily mean a physical or mechanical connection, but can include an electrical connection, whether direct or indirect. The terms "upper", "lower", "left", "right", and the like, are used only to indicate relative positional relationships, and when the absolute positions of the described objects change, the relative positional relationships may also change accordingly.

[0029] Embodiment one

[0030] The application provides a precision polishing grinding head with controllable deformation in different zones, as shown in Figure 1 and Figure 2As shown, it includes a partition base 1, a positioning block 2 is provided at the center below the partition base 1, and at least one set of connecting rod assemblies 3 are provided above the partition base 1. The partition base 1 is provided with at least one partition unit, and the partition units are evenly distributed on the surface of the partition base 1. The connecting rod assemblies 3 correspond to the number and position of the partition units. The partition base 1 can realize the partitioned control of the curvature radius of the working surface of the polishing grinding head. The partition base 1 includes multiple independent partition units, each of which can independently adjust its corresponding curvature radius to adapt to optical elements with complex curved surfaces. The polishing grinding head described in this embodiment has six connecting rod assemblies 3 and six partition units, which are evenly distributed on the upper surface of the partition base 1.

[0031] Connecting rod assembly 3 Figure 3 As shown, the structure comprises a base 31, which is connected to the partition base 1 via bolts 32. A fork rod 33 and a driver support rod 34 are arranged parallel to the base 31. A shape memory alloy driver 35 is connected to the top of the driver support rod 34. The shape memory alloy driver 35 and the fork rod 33 are movably connected via a transverse amplification link 36. The tail end of the transverse amplification link 36 is hinged to a first link 37, which is hinged to a second link 38. The shape memory alloy driver 35 is connected to the head end of the transverse amplification link 36, and the fork rod 33 is connected to the middle section of the transverse amplification link 36. The shape memory alloy driver 35 deforms when stimulated by an electric current to achieve precise control of the curvature radius of the working surface of the flexible polishing head 6. The core function of the connecting rod assembly 3 is to achieve precise amplification of force and displacement and transmit them to the curvature adjustment head 4 by adjusting the proportional relationship between the fulcrum position and the lever arm length. In this embodiment, the shape memory alloy driver 35 is made of nickel-titanium alloy, which has excellent shape memory effect and fatigue resistance.

[0032] The top of the connecting rod assembly 3 is connected to a curvature adjustment head 4. Figure 4 As shown, the outer contour is hemispherical, and the curvature adjustment head 4 is provided with multiple layers of gaps. A flexible polishing head 6 is positioned above the curvature adjustment head 4 and in direct contact with the curvature adjustment head 4. The flexible polishing head 6 adjusts the curvature radius of the working surface through the curvature adjustment head 4. The flexible polishing head 6 directly contacts the surface of the optical component to perform precision polishing on the optical component. The flexible polishing head 6 is required to be made of a flexible material with a high elastic modulus and wear resistance to ensure that it can adapt to the varying curvatures of the optical component surface during the polishing process.

[0033] The curvature adjustment head 4 utilizes a multi-layered, stacked structure with precisely calculated gaps between each layer, enabling controlled deformation when subjected to the forces of the connecting rod assembly 3. This multi-layered, gap-filled design not only enhances the flexibility of the curvature adjustment head 4 but also enables smoother and more continuous curvature adjustment, avoiding the discontinuous deformation that can occur during adjustment with traditional single-layer structures. In this embodiment, the curvature adjustment head 4 is made of a titanium alloy with an elastic modulus of 80-120 GPa, exhibiting excellent elastic recovery and long-term stability.

[0034] The adjustment of the curvature radius of the working surface of the flexible polishing head 6 is as follows: when the flexible polishing head 6 is pushed or pulled by the curvature adjustment head 4, it can undergo precise and controllable shape change. The curvature adjustment head 4 is acted upon by the force of the connecting rod assembly 3. This allows the flexible polishing head 6 to accurately adjust the curvature radius of its working surface in real time when polishing different positions of the workpiece to adapt to the workpiece surface with different curvatures. By controlling the axial (up and down) movement of the curvature adjustment head 4, the curvature radius of the central area of ​​the flexible polishing head 6 can be changed, such as Figure 5 By controlling the curvature adjustment head 4 angle swing (tilt), the radius of curvature of the flexible polishing head 6 edge area can be adjusted, such as Figure 6 As shown; this design improves the accuracy and adaptability of the polishing process.

[0035] A protective shell 7 is provided on the outside of the connecting rod assembly 3. The flexible polishing head 6 and the protective shell 7 are connected through the grinding head frame 5. The entire device is provided with a driving circuit. The driving circuit is used to output an excitation current to the shape memory alloy driver 35, triggering the austenite phase transformation of the shape memory alloy through the Joule heating effect, thereby generating deformation. The control principle is as follows: Figure 7As shown in the figure, the drive circuit includes a main control system that receives signal inputs from the machining path storage unit and the workpiece topography measurement module. The main control system inputs control variables to the shape memory alloy driver control module, which drives the linkage assembly to move and amplify the displacement acting on the curvature adjustment head. The curvature adjustment head controls the deformation of the flexible polishing head for workpiece machining. The drive circuit is equipped with a power supply module to provide power for the entire system. Specifically, the drive circuit applies a specific control current to each shape memory alloy driver 35. The heat generated by the current triggers a phase change in the shape memory alloy material, causing it to elongate or shorten, resulting in precisely controllable micro-displacement. This displacement is then amplified by the transverse amplification link 36. The amplified force or displacement directly drives the curvature adjustment head 4, causing it to produce corresponding axial displacement or angular swing. Each partition of the partition base 1 is equipped with an independent shape memory alloy driver 35. The drive circuit controls the entire device, enabling coordinated regulation of the extension and contraction of the shape memory alloy drivers 35 in different partitions, thereby precisely controlling the tilt angle and posture of the curvature adjustment head 4. Ultimately, independent and precise control of the curvature radius of different regions of the flexible polishing head 6 is achieved.

[0036] When the polishing grinding head described in this embodiment is used, the specific working process is as follows:

[0037] S1. Install the workpiece to be processed in a special fixture to ensure that the workpiece surface is completely immersed in the polishing liquid medium. For optical components, fixation is generally achieved through a vacuum adsorption system; for mechanical parts, mechanical fixtures or electromagnetic adsorption systems can be selected for fixation based on the material properties and shape of the workpiece.

[0038] S2. Install the polishing head described in this embodiment on the polishing equipment through the positioning block 2, control the polishing head to approach the workpiece surface, and gently contact the polishing head with the workpiece surface to complete the tool setting. The system automatically records the current position as the processing reference surface.

[0039] S3. Start the rotating mechanism to rotate the workpiece at high speed. The polishing head polishes the workpiece according to the shape of the workpiece and the processing requirements according to the pre-set polishing path. During the polishing process, the polishing head can automatically adjust the curvature radius of the working surface according to the curvature of the polishing area to meet the processing requirements of complex curved surfaces.

[0040] S4. The drive circuit outputs a programmable excitation current to the shape memory alloy driver 35, triggering the austenite phase transformation of the shape memory alloy through the Joule heating effect, resulting in a controllable deformation. This deformation is transmitted to the flexible polishing head 6 via the connecting rod assembly 3, enabling dynamic adjustment of the curvature radius of the working surface. The partitioned base 1 utilizes an array of independent control units, allowing each partition to be individually excited to achieve localized correction of the working surface curvature. For optical components, this adjustment can significantly improve surface roughness and surface accuracy; for mechanical parts, this adjustment can optimize surface quality and material removal efficiency.

[0041] S5. During the polishing process, the workpiece morphology measurement module monitors the surface shape of the workpiece in real time and feeds the measurement data back to the main control system. The main control system calculates the curvature adjustment required for each partition based on the preset surface accuracy requirements, and adjusts the excitation current of each shape memory alloy driver control module accordingly, forming a closed-loop control system to ensure the accuracy and stability during the polishing process.

[0042] Therefore, the present invention adopts the above-mentioned partitionable and controllable deformation precision polishing grinding head. Through the partition base and the independent shape memory alloy driver array, it can independently control the curvature radius of the center and edge of the flexible polishing head, optimize the edge pressure distribution, bring more stable contact stiffness and more uniform pressure distribution, suppress or compensate for the problem of excessive or insufficient edge removal caused by factors such as linear speed changes, improve the surface accuracy of the workpiece edge, and achieve finer and more localized surface control; at the same time, the shape memory alloy driver is a solid-state driving element, and with the lateral amplification connecting rod, it can achieve the required driving force and displacement in a relatively compact space, and is easy to integrate into existing polishing equipment or robot systems.

[0043] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit the same. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that they can still modify or replace the technical solutions of the present invention with equivalents, and these modifications or equivalent replacements cannot cause the modified technical solutions to deviate from the spirit and scope of the technical solutions of the present invention.

Claims

1. A precision polishing grinding head with partitionable and controllable deformation, characterized by: It includes a partition base, a positioning block is provided at the center below the partition base, and at least one group of connecting rod assemblies are provided above the partition base, the connecting rod assembly includes a shape memory alloy driver, and the top of the connecting rod assembly is connected to a curvature adjusting head, the outer contour of the curvature adjusting head is hemispherical and adopts a multi-layer stacked structure, with gaps between each layer, and the gap structure is used to generate controllable deformation when the curvature adjusting head is subjected to force; a flexible polishing head is provided above the curvature adjusting head, and a protective shell is provided on the outside of the connecting rod assembly, and the flexible polishing head and the protective shell are connected through a grinding head frame, and the device as a whole is provided with a driving circuit, and the driving circuit controls the shape memory alloy driver to realize partitioned controllable deformation of the flexible polishing head.

2. The precision polishing grinding head with partitionable and controllable deformation according to claim 1, characterized in that: The partition base is provided with at least one partition unit, and the partition units are evenly distributed on the surface of the partition base. The connecting rod assembly corresponds to the number and position of the partition units, and the connecting rod assembly is used to independently control the partitions of the flexible polishing head.

3. The precision polishing grinding head with partitionable and controllable deformation according to claim 1, characterized in that: The connecting rod assembly includes a base, which is connected to the partition base by bolts, a fork rod and a driver support rod are arranged parallel to the top of the base, the top of the driver support rod is connected to the shape memory alloy driver, the shape memory alloy driver and the fork rod are movably connected through a transverse amplification connecting rod, the tail end of the transverse amplification connecting rod is hinged to a first connecting rod, the first connecting rod is hinged to a second connecting rod, the second connecting rod is connected to the curvature adjustment head, and the second connecting rod is used to transmit the displacement of the shape memory alloy driver to the curvature adjustment head.

4. The precision polishing grinding head with partitionable and controllable deformation according to claim 3, characterized in that: The shape memory alloy driver is connected to the head end of the transverse amplification connecting rod, and the fork rod is connected to the middle section of the transverse amplification connecting rod.

5. The precision polishing grinding head with partitionable and controllable deformation according to claim 1, characterized in that: The flexible polishing head is in direct contact with the curvature adjusting head, and the flexible polishing head adjusts the curvature radius of the working surface through the curvature adjusting head.

6. The precision polishing grinding head with partitionable and controllable deformation according to claim 3, characterized in that: The driving circuit includes a main control system, which receives signal inputs from a processing path storage unit and a workpiece shape measurement module. The main control system inputs a control quantity to a shape memory alloy driver control module. The shape memory alloy driver control module drives the connecting rod assembly to move and amplifies the displacement acting on the curvature adjustment head. The curvature adjustment head controls the flexible polishing head to generate deformation and is used for workpiece processing. The driving circuit is provided with a power supply module.

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