Multi-point pressurization control device for plane machining of optical element

Abstract

The invention relates to a multi-point pressurization control device for optical element plane processing, which comprises a plurality of pressure blocks arranged according to certain rows and columns and positioned on the top surface of an optical element; a corresponding feedback piece is arranged on the top face of each pressing block, the multiple feedback pieces are electrically connected with the pressure control machine, and the pressure control machine conducts zoning control over machining pressure through the feedback pieces. The ballasting back plate selects the arrangement weight increment quantity and materials according to the maximum pressure applied in the machining process and is located at the top of the feedback piece; the workpiece disc is located at the top of the ballasting back plate and provides connection positions for the element clamps, and the bottoms of the element clamps clamp the side edges of the optical element; the workpiece shaft is located above the workpiece disc and connected with the machine tool spindle through the spindle connecting piece. The semi-automatic device convenient and fast to operate, capable of achieving multi-point pressurization and zone control has the remarkable technical effects on the aspects of improving the machining efficiency, enhancing the machining precision, reducing the operation difficulty, improving the safety and the like.

Description

Technical Field

[0001] The invention relates to the technical field of optical element manufacturing, and more particularly to a multi-point boost control device for plane processing of optical elements. Background Art

[0002] Large-diameter ultra-thin planar components are widely used in optical processing, mechanical processing and other fields. Since the diameter-to-thickness ratio of these components is very large (up to 60:1 or even larger, so they are called ultra-thin planar components), uneven pressure is prone to occur during the processing process, making surface shape control extremely difficult. In order to solve this problem, a pressurized backplane of equal size is usually placed on the upper surface of the component. However, in order to ensure that the component is evenly pressurized, a flexible pad needs to be bonded to the surface where the pressurized backplane contacts the component, so that the contact between the component and the pressurized backplane is flexible. This processing method can converge the surface shape of the component to a certain extent, but since the pressurization method is integral pressurization, a higher flatness requirement is placed on the pressurized backplane to ensure that the component is evenly pressurized. Usually, the flatness of the pressurized backplane needs to be controlled within 2μm, and it is difficult to obtain such a high flatness through mechanical processing. In addition, the pressurization process of the pressurized backplane is generally operated by processing personnel, and the fit between the component and the pressurized backplane cannot be accurately guaranteed. Poor fit can easily lead to asymmetric shapes such as warped corners or collapsed edges on the component surface, which is extremely unfavorable to the convergence of the component surface.

[0003] In summary, the existing pressurization methods for large-diameter ultra-thin planar components still have the following disadvantages: 1) Integral pressurization is extremely unfavorable for local control of component surface shape and cannot achieve local surface convergence of components; 2) Integral pressurization easily causes deformation of thin plate components and cannot effectively control component shape; 3) Integral pressurization may increase the local stress of components, which is not conducive to component processing; 4) In order to effectively achieve material removal, the weight of the pressurized backplane is usually large, and it is time-consuming and labor-intensive to operate solely by manpower and has certain safety hazards.

[0004] Therefore, how to provide a multi-point boost control device for planar processing of optical elements that solves the above-mentioned problems is an issue that technical personnel in this field urgently need to solve. Summary of the invention

[0005] To this end, the purpose of the present invention is to solve the technical problems in the prior art that the overall pressurization of optical elements is not conducive to the local control of the element surface shape and cannot achieve the local surface convergence of the element, and proposes a multi-point pressurization control device for planar processing of optical elements.

[0006] The technical solution of the present invention is a multi-point boost control device for plane processing of optical elements, comprising:

[0007] A plurality of pressure blocks are arranged in certain rows and columns and are located on the top surface of the optical element;

[0008] Feedback components, each of the pressure blocks has a corresponding feedback component on its top surface, and the plurality of feedback components are electrically connected to a pressure control machine, and the pressure control machine controls the processing pressure by zones through the feedback components;

[0009] A weight back plate, the weight quantity and material of which are selected according to the maximum pressure applied during the processing, and which is located on the top of the feedback member;

[0010] A workpiece plate, located on top of the weighted back plate, and providing connection locations for a plurality of component fixtures, wherein the bottom of the component fixtures is clamped from the side of the optical element;

[0011] and a workpiece shaft, which is located above the workpiece disk and connected to the machine tool spindle through a spindle connector.

[0012] According to the technical solution of the present invention, a soft pad made of flexible material is adhered to the lower surface of the pressure block.

[0013] According to the technical solution of the present invention, the workpiece disc is connected to the weight back plate via a guide rod to adjust the distance between the weight back plate and the workpiece disc.

[0014] According to the technical solution of the present invention, the guide rod adjusts the distance between the weight back plate and the workpiece disk to a range of ≥200 mm.

[0015] According to the technical solution of the present invention, the feedback element is piezoelectric ceramic.

[0016] According to the technical solution of the present invention, the feedback member and the weight back plate are connected via a plurality of supporting members.

[0017] According to the technical solution of the present invention, a plurality of support blocks are installed on the top of the workpiece disk, a support plate is installed on the top of the support block, the pressure control machine and its power supply are installed on the top of the support plate, and the bottom of the workpiece shaft passes through the support plate and is connected to the workpiece disk.

[0018] According to the technical solution of the present invention, a pressure display is also installed on the support plate, and the pressure display is electrically connected to the host computer.

[0019] According to the technical solution of the present invention, the weighted back plate provides a maximum pressure value ≥ 10kgf.

[0020] According to the technical solution of the present invention, the maximum applied pressure of each of the pressure blocks is ≥100N.

[0021] It can be seen from the above technical solution that, compared with the prior art, the technical effects of the present invention are as follows:

[0022] The present invention provides a semi-automatic device which is easy to operate, can apply pressure at multiple points and can be controlled by partitioning. The pressure in each region can be adjusted according to the existing shape of the component, and the processing pressure in each region can be individually controlled according to the actual shape of the component, so that the surface shape of the component can be directionally converged. On the premise that the pressure partitioning is controllable, the surface shape convergence speed is accelerated, and the problem of local overpressure or underpressure that may occur in the traditional integral pressurization method is avoided, thereby significantly improving the processing efficiency. This is of great significance for the rapid processing of ultra-thin components.

[0023] Moreover, this device can be directly fixed on the spindle box of the machine tool. The processing personnel only need to set the processing pressure in the program and transmit it to the pressure block to complete the pressurization process of the component, which saves time and effort and is convenient to operate.

[0024] The lower surface of the pressure block in the present invention is pasted with a soft pad made of a flexible material, which helps to achieve flexible contact between the pressure block and the optical element, reducing damage and deformation that may be caused by hard contact. At the same time, the use of feedback elements (such as piezoelectric ceramics) makes pressure control more precise and accurate, further improving processing accuracy.

[0025] The present invention designs a semi-automatic device, which realizes automatic zoning control of processing pressure through the cooperation of a pressure control machine and a feedback member. This design simplifies the operation process, reduces the difficulty of operation, and enables operators to perform processing operations more conveniently.

[0026] The electrical connection between the pressure display of the present invention and the host computer enables the operator to monitor the pressure changes during the processing in real time, timely discover and deal with potential safety hazards, and improve safety. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying creative work.

[0028] Figure 1 A schematic diagram of the structure of a multi-point boost control device for plane processing of optical elements provided by the present invention;

[0029] Figure 2 A side view of the present invention is shown;

[0030] Figure 3 The schematic diagram of the structure of the present invention when viewed from a bottom-up perspective is shown;

[0031] Figure 4A schematic diagram showing the connection between a feedback member, a weighted back plate and multiple support members is shown. DETAILED DESCRIPTION

[0032] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present invention, and should not be construed as limiting the present invention.

[0033] Since the diameter-to-thickness ratio of existing large-diameter ultra-thin planar components is very large (can reach 60:1, or even larger, so they are called ultra-thin planar components), uneven pressure is prone to occur during processing, making surface shape control extremely difficult. In order to solve this problem, a pressure backing plate of equal size is usually placed on the upper surface of the component to achieve manual integral pressure application, but integral pressure application is extremely unfavorable for local control of the component surface shape and cannot achieve local surface shape convergence of the component; integral pressure application is prone to deformation of thin plate components and cannot effectively control the shape of the component; integral pressure application may increase the stress on the local component, which is not conducive to component processing; in order to effectively achieve material removal, the weight of the pressure backing plate is usually large, and manual operation alone is time-consuming and labor-intensive and has certain safety hazards.

[0034] In view of this, the technical solution of the present invention provides a multi-point boost control device for plane processing of optical elements, see the attached Figure 1-3 ,include:

[0035] The pressure blocks 9 are in multiple numbers and arranged in certain rows and columns and are located on the top surface of the optical element 16;

[0036] Feedback member 8, each of the pressure blocks 9 has a corresponding feedback member 8 on its top surface, and the plurality of feedback members 8 are electrically connected to a pressure control machine 11, and the pressure control machine 11 controls the processing pressure by zones through the feedback members 8;

[0037] The weight back plate 5 is selected and arranged with the weight increase quantity and material according to the maximum pressure applied during the processing, and is located on the top of the feedback member 8;

[0038] A workpiece plate 4 is located on top of the weighted back plate 5 and provides connection positions for a plurality of component fixtures 6, wherein the bottom of the component fixtures 6 is clamped from the side of the optical element 16;

[0039] The workpiece shaft 12 is located above the workpiece disk 4 and is connected to the machine tool spindle through the spindle connecting member 1. The lower end of the spindle connecting member 1 can be connected to the workpiece shaft 12 by screws, and the upper end surface of the spindle connecting member 1 can be connected to the machine tool spindle and evenly distributed with screw holes, and the size and spacing of the screw holes can be fixed according to actual conditions.

[0040] The above scheme operates a convenient, multi-point pressurization, and zone-controlled semi-automatic device. The pressure of each area can be adjusted according to the existing shape of the component, and the processing pressure of each area can be individually controlled according to the actual shape of the component, so that the surface shape of the component can be directionally converged. Under the premise of making the pressure zone controllable, the surface shape convergence speed is accelerated, and the local overpressure or underpressure problems that may occur in the traditional integral pressurization method are avoided, thereby significantly improving the processing efficiency. This is of great significance for the rapid processing of ultra-thin components. In addition, this device can be directly fixed on the machine tool spindle box. The processing personnel only need to set the processing pressure in the program and transmit it to the pressure block to complete the pressurization process of the component, which saves time and effort and is convenient to operate.

[0041] The pressure blocks 9 of the present invention can be arranged in 4×4 or 5×5 equal spacings. The size of the pressure blocks is determined by the size of the component and the number of partitions. The pressure blocks are evenly distributed on the upper surface of the component, so that the overall processing pressure of the component can be controlled in partitions.

[0042] On the basis of the above solution, a soft pad made of flexible material is attached to the lower surface of the pressure block 9, which is beneficial to further reduce the damage and deformation of the optical element caused by hard contact after the partial pressure control.

[0043] Among them, if the maximum applied pressure of the weight back plate 5 is 30kgf, each weight back plate can provide 10kgf, then three weight back plates are needed. The material is selected according to the needs.

[0044] In addition, the bottom of the component fixture 6 of the present invention can adopt a clean stopper 7 of polytetrafluoroethylene or the like to ensure that no new pollution source is introduced during the component clamping process.

[0045] In the description of the present invention, it is necessary to understand that the orientations or positional relationships indicated by the terms "upper", "lower", "top", "bottom", "inside", "outside", etc. are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0046] Advantageously, the workpiece disk 4 is connected to the weighted back plate 5 through a guide rod 15 to adjust the distance between the weighted back plate 5 and the workpiece disk 4. The bottom of the guide rod 15 can be fixed to the weighted back plate 5, and the top can be detachably connected to the workpiece disk 4. The studs are connected with nuts to facilitate the adjustment of the distance between the weighted back plate 5 and the workpiece disk 4 to meet the processing requirements of workpieces of different thicknesses.

[0047] Specifically, because the size of the existing component fixture is usually fixed, and the thickness of different workpieces can be different, in order to safely clamp the workpiece, the end of the component fixture is usually placed as close as possible to the end of the component in the vertical direction. At this time, the position of the component fixture needs to be adjusted in the vertical direction. When the machine tool spindle moves upward or downward along the Z direction, the guide rod 15 plays the role of adjusting the distance. Therefore, the above design can meet the processing needs of workpieces of different thicknesses.

[0048] The guide rod 15 adjusts the distance between the weight back plate 5 and the workpiece disk 4 to a range of ≥200 mm.

[0049] In one embodiment of the present invention, the feedback element 8 is preferably a piezoelectric ceramic, and the pressure resolution of the piezoelectric ceramic is ≤1 N. Feedback elements such as piezoelectric crystals may also be used.

[0050] In other embodiments of the present invention, the feedback member 8 and the weight back plate 5 are connected by a plurality of support members 17, wherein the support members 17 may be screws. Figure 4 .

[0051] A plurality of support blocks 10 are installed on the top of the workpiece disk 4, a support plate 3 is installed on the top of the support block 10, the pressure control machine 11 and its power supply 14 are installed on the top of the support plate 3, and the bottom of the workpiece shaft 12 passes through the support plate 3 and is connected to the workpiece disk 4. The plurality of support blocks 10 connect the workpiece disk 4 and the support plate 3, and the contact portion between the top of the support block 10 and the support plate 3 is fixed by screw holes and fixing screws.

[0052] The lower end of the workpiece shaft 12 and the workpiece disk 4 may be connected via screws.

[0053] In an embodiment of the present invention, a pressure display 2 is also installed on the support plate 3, and the pressure display 2 is electrically connected to the host computer 13. The electrical connection between the pressure display and the host computer enables the operator to monitor the pressure changes during the processing process in real time, promptly discover and deal with potential safety hazards, and improve safety.

[0054] The host computer 13 has dedicated prior art software that can monitor and control the processing pressure of the component in real time, so as to quickly converge the surface shape of the component.

[0055] In the above embodiments of the present invention, the maximum pressure value provided by the weighted back plate 5 is ≥10kgf. The maximum applied pressure of each of the pressure blocks 9 is ≥100N.

[0056] During operation, the operator uses screws to connect the spindle connection component 1 to the machine tool spindle to complete the assembly of the device. The optical element 16 to be processed is placed on the polishing disk, and the pressure block 9 is controlled by the machine tool CNC system to approach the upper surface of the optical element 16 until it is fitted and aligned, so that the pressure block 9 completely covers the upper surface of the element 16. The polytetrafluoroethylene block 7 at the bottom of the element fixture 6 is close to the four sides of the optical element 16 and tightened, and the screws pre-placed on the top of the element fixture 6 are locked to complete the clamping preparation of the element 16. The operator sets and pressurizes the processing pressure of each area on the host computer 13 according to the actual shape of the actual optical element 16.

[0057] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral 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.

[0058] Before applying pressure, the present invention needs to determine the value of the pressure applied in each area. Assume that the highest point in the component surface is H and the target surface is H t The highest point of each pressurized area is H i , then the surface shape of each area to be converged △H=H i -H t Chemical mechanical polishing usually follows the Preston formula, namely: MRR = KPV. Among them, K is a constant related to the process, P is the processing pressure, and V is the processing speed. The surface convergence amount is the part of the component to be removed, so the removal efficiency MRR is proportional to the surface convergence amount △H, △H = a×MRR, that is, H i -H t =a×K×V×P i , i=1, 2, 3….

[0059] Assuming that the processing speed V remains unchanged, then a×K×V is a constant, set to m, then H i -H t =m×P i , the staff needs to obtain the value of the constant m based on experiments, and then determine the pressure applied to each area based on the existing surface shape and the target surface shape.

[0060] Furthermore, on the basis of the above formula, the processing pressure of each area is set by the program of the host computer, so as to effectively control the directional convergence of the component surface shape while ensuring the processing efficiency.

[0061] After the pressurization process of the above-mentioned components is completed, the operator starts the machine tool processing program and starts processing the optical component 16. During the processing of the optical component 16, the operator can monitor the processing pressure in real time through the display panel of the pressure display 2. If there is a sudden change in pressure, the upper computer 13 can adjust and control the pressure in real time at any time.

[0062] Since the present invention adopts a multi-point partitioned pressurization method, it has a directional convergence effect on the shape of the optical element 16, so that the element can be processed quickly and the surface shape of the optical element 16 can be accurately controlled, and the processing process is more deterministic.

[0063] In summary, the semi-automatic device provided by the present invention, which is convenient to operate, has multi-point pressurization, and partition control, has significant technical effects in improving processing efficiency, enhancing processing accuracy, reducing operating difficulty, and improving safety. This has important reference significance and application value for the rapid processing of ultra-thin components.

[0064] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine different embodiments or examples described in this specification.

[0065] Although the embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations of the present invention. A person skilled in the art may change, modify, replace and vary the above embodiments within the scope of the present invention.

Claims

1. A multi-point boost control device for plane processing of optical elements, characterized in that: include: A plurality of pressure blocks (9) are arranged in rows and columns and are located on the top surface of the optical element (16); Feedback components (8), each of the pressure blocks (9) has a corresponding feedback component (8) on its top surface, and the plurality of feedback components (8) are electrically connected to a pressure control machine (11), and the pressure control machine (11) controls the processing pressure by zones through the feedback components (8); A weighted back plate (5), the weighted quantity and material of which are selected according to the maximum pressure applied during the processing, and which is located on the top of the feedback member (8); A workpiece plate (4) is located on top of the weighted back plate (5) and provides connection positions for a plurality of element fixtures (6), wherein the bottom of the element fixtures (6) is clamped from the side of the optical element (16); and a workpiece shaft (12), which is located above the workpiece disk (4) and is connected to the machine tool spindle via a spindle connector (1).

2. The multi-point boost control device for plane processing of optical elements according to claim 1, characterized in that: A soft pad made of flexible material is adhered to the lower surface of the pressure block (9).

3. The multi-point boost control device for plane processing of optical elements according to claim 1, characterized in that: The workpiece plate (4) is connected to the weighted back plate (5) via a guide rod (15) for adjusting the distance between the weighted back plate (5) and the workpiece plate (4).

4. The optical element plane processing multi-point boost control device according to claim 3, characterized in that: The guide rod (15) adjusts the distance between the weight back plate (5) and the workpiece plate (4) to a range of ≥200 mm.

5. The optical element plane processing multi-point boost control device according to claim 1, characterized in that: The feedback element (8) is piezoelectric ceramic.

6. The optical element plane processing multi-point boost control device according to claim 1, characterized in that: The feedback member (8) and the weighted back plate (5) are connected via a plurality of supporting members.

7. The optical element plane processing multi-point boost control device according to claim 1, characterized in that: A plurality of support blocks (10) are installed on the top of the workpiece disk (4), a support plate (3) is installed on the top of the support block (10), the pressure control machine (11) and its power supply (14) are installed on the top of the support plate (3), and the bottom of the workpiece shaft (12) passes through the support plate (3) and is connected to the workpiece disk (4).

8. The optical element plane processing multi-point boost control device according to claim 7, characterized in that: A pressure display (2) is also installed on the support plate (3), and the pressure display (2) is electrically connected to the host computer (13).

9. The multi-point boost control device for plane processing of optical elements according to any one of claims 1 to 8, characterized in that: The weighted back plate (5) provides a maximum pressure value of ≥10 kgf.

10. The optical element plane processing multi-point boost control device according to any one of claims 1 to 8, characterized in that: The maximum applied pressure of each of the pressure blocks (9) is ≥100N.

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