A multi-spindle machining tool head for high-steepness optical element machining

Abstract

The application discloses a multi-spindle machining tool head for high-steepness optical element machining, comprising a sensor device, a polishing component and a grinding machining component; the polishing component comprises a polishing spindle box shell, a first machining tool, a second machining tool, a torque motor, an angular contact ball bearing, a hydraulic expansion clamp and a double-end hollow spindle; the double-end hollow spindle extends out two ends from the polishing spindle box shell, the hydraulic expansion clamp is arranged on the two ends of the double-end hollow spindle and is used for fixing the first machining tool and the second machining tool; the grinding machining component comprises a grinding spindle used for clamping an optical element, a circular-arc grinding wheel used for grinding machining of the optical element and a belt pulley transmission device for providing power for the circular-arc grinding wheel; the double-end hollow spindle of the polishing component and the grinding spindle of the grinding machining component are vertically distributed. The application can flexibly replace machining tools according to machining process requirements, has a compact overall structure, effectively avoids machining interference and is suitable for machining large-aperture high-steepness optical elements.

Description

Technical Field

[0001] The present invention belongs to the field of ultra-precision machining, and in particular relates to a multi-spindle machining tool head for machining high-steepness and large-aperture aspheric optical elements. Background Art

[0002] At present, the traditional processing procedures for high-steepness and large-aperture aspheric optical elements are rough grinding-fine grinding-polishing. The demand for high-precision batch processing of high-steepness and large-aperture aspheric optical elements urgently requires improving the existing ultra-precision grinding, rapid polishing and on-site detection and related technical levels of high-steepness and large-aperture aspheric optical elements.

[0003] The current problem is that the existing machining process consists of rough grinding, fine grinding, and polishing. Changing the machining process requires a new machine. Moving the workpiece from one machine to the next also requires time and labor. Furthermore, due to the different clamping devices used to mount the workpiece, re-clamping can cause clamping errors. Reassembly between machines also introduces new assembly errors. Consequently, reassembly wastes a significant amount of manpower and resources. Furthermore, when working with steeply angled components, traditional grinding methods must consider the issue of machining interference.

[0004] Therefore, how to solve the problem of waste of manpower and material resources caused by reassembly of different processes, improve efficiency, and avoid errors caused by repeated clamping is one of the important technical problems that technical personnel in this field need to solve. In addition, in order to avoid interference problems during the processing of high-steepness optical components, it is also necessary to make the processing tool head structure compact, control the dimensions of the processing tool head and transmission parts, and improve the accuracy and degree of freedom of the processing tool head.

[0005] To this end, an invention patent with publication number CN116252211A discloses an integrated processing equipment for grinding, polishing and inspecting small-aperture aspheric optical elements, comprising a bed (100) and a grinding mechanism (200), a rough polishing mechanism (300), a fine polishing mechanism (400), a detection mechanism and a workpiece clamping and conveying mechanism (500) for clamping and conveying small-aperture aspheric optical elements, wherein the grinding mechanism (200) comprises a grinding spindle (201) for clamping the optical element, a grinding wheel (202) for grinding the optical element, a first X-axis motion mechanism for driving the grinding wheel (202) to move along the X-axis direction, and a second X-axis motion mechanism for driving the grinding wheel (202) to move along the X-axis direction. A first Z-axis motion mechanism for the wheel (202) to move along the Z-axis direction and a first B-axis rotation mechanism for driving the grinding wheel to rotate around the B-axis, the axis of the grinding spindle (201) being parallel to the Z-axis; the rough polishing mechanism (300) comprising a rough polishing spindle (301) for clamping the optical element, a rough polishing head (302) for rough polishing the optical element, a second X-axis motion mechanism for driving the rough polishing head (302) to move along the X-axis direction, a second Z-axis motion mechanism for driving the rough polishing head (302) to move along the Z-axis direction, and a second B-axis rotation mechanism for driving the rough polishing head (302) to rotate around the B-axis, the axis of the rough polishing spindle (301) being parallel to the Z-axis.

[0006] Another invention patent, with publication number CN111376142A, discloses a method and device for CNC milling, forming and polishing of large-aperture aspheric mirrors. The CNC machine tool spindle uses an annular grinding wheel tool with a diameter larger than the semi-diameter of the aspheric surface. When in use, the annular grinding wheel tool can be replaced with an annular polishing disk.

[0007] In the above-mentioned prior art, although the prior art provides technical inspiration that the grinding wheel and the polishing head can be integrated into a unit, its structure is scattered and complicated, and several component modules are installed on the same machine without truly achieving integration, and its practicality is not strong. Summary of the Invention

[0008] A brief overview of embodiments of the present invention is provided below to provide a basic understanding of certain aspects of the present invention. It should be understood that the following overview is not an exhaustive overview of the present invention. It is not intended to identify key or important aspects of the present invention, nor is it intended to limit the scope of the present invention. Its purpose is simply to present certain concepts in a simplified form as a prelude to the more detailed description discussed later.

[0009] In order to solve the above-mentioned problems in the prior art, the present application provides a multi-spindle processing tool head with a compact structure and high degree of freedom, so as to more flexibly replace processing tools. At the same time, the polishing head is prone to processing interference when facing high-steepness optical elements. The present invention also improves the polishing head structure suitable for the processing tool head to address this problem, avoiding the processing interference problem caused by processing high-steepness optical elements and adapting to the processing needs of high-steepness large-aperture aspheric optical elements.

[0010] Specifically, the present application provides a multi-spindle machining tool head for machining high-steepness optical elements, which includes a sensor device, a polishing component, and a grinding component, wherein the polishing component is mounted on the upper portion of the grinding component, and the sensor device is mounted on the upper portion of the polishing component;

[0011] Wherein, the polishing component includes a polishing spindle box housing, a first processing tool, a second processing tool, a torque motor, an angular contact ball bearing, a hydraulic expansion clamp and a double-headed hollow spindle; the double-headed hollow spindle is a hollow component, which is installed in the polishing spindle box housing through two angular contact ball bearings separated from each other, and the double-headed hollow spindle can rotate but cannot move axially; the torque motor is arranged in the polishing spindle box housing, and is installed on the double-headed hollow spindle around the rotation axis of the tool to control the speed of the double-headed hollow spindle; the rotor of the torque motor is fixedly connected to the double-headed hollow spindle, and the stator of the torque motor concentrically surrounds the rotor and is fixed to the polishing spindle box housing to prevent them from rotating relative to each other; the double-headed hollow spindle extends outward from the polishing spindle box housing at both ends, and the hydraulic expansion clamp is arranged on both ends of the double-headed hollow spindle for fixing the shank ends of the first processing tool and the second processing tool;

[0012] The grinding components include a grinding spindle for clamping the optical element, a circular arc grinding wheel for grinding the optical element, and a pulley transmission device for providing power to the circular arc grinding wheel;

[0013] The double-headed hollow spindle of the polishing part and the grinding spindle of the grinding part are arranged vertically;

[0014] The rotation center of the multi-spindle machining tool head is located at the center of the three machining tools (the first machining tool T1, the second machining tool T2 and the arc grinding wheel at the bottom), so that the multi-spindle machining tool head rotates around the rotation center as a whole, thereby effectively reducing the travel waste and tool collision caused by switching tool heads, and has machining flexibility.

[0015] The polishing component can accommodate two processing tools (a first processing tool and a second processing tool) and a spindle (a double-headed hollow spindle), and the grinding processing component can accommodate a processing tool (arc grinding) wheel and a spindle (grinding spindle), wherein the double-headed hollow spindle and the grinding wheel tool spindle are vertically distributed in space.

[0016] The torque motor in the polishing unit consists of a stator and a rotor. The stator is fixed to the polishing spindle housing, while the rotor is fixed to the double-ended hollow spindle. The double-ended hollow spindle and the polishing spindle housing are secured via a pair of angular contact ball bearings. The two machining tools are secured to the double-ended hollow spindle via hydraulic expansion clamps. The torque motor is fixed in the center of the double-ended hollow spindle, which is also fixed in the center of the polishing spindle housing. The machining tools, double-ended hollow spindle, and torque motor are coaxial.

[0017] As an embodiment, the first and second machining tools are machining tool heads suitable for high-steepness aspheric optical components, and can be arc grinding wheels, cup grinding wheels, polishing heads, or long-handled cup grinding wheels. The machining tool heads can be interchanged with long-handled cup grinding wheels and arc grinding wheels to grind high-steepness optical components, while controlling the thickness of the arc grinding wheel transmission portion and the radius of the arc grinding wheel to avoid machining interference caused by the high steepness of the workpiece. For grinding the interior of high-steepness, large-aperture aspheric optical components, which have a high internal steepness, the long-handled cup grinding wheel can prevent machining interference while grinding. Furthermore, the double-headed hollow spindle can also be equipped with a short-handled cup grinding wheel and polishing head to grind and polish the surface of high-steepness, large-aperture aspheric optical components.

[0018] The double-headed hollow spindle can be used to install processing tools, such as cup grinding wheels and polishing heads. Cup grinding wheels and polishing heads of different sizes are fixed to both ends of the double hollow spindle through hydraulic expansion clamps. The cup grinding wheel is used for precision grinding of the inner and outer surfaces of high-steepness optical components, and the polishing head is used for polishing high-steepness optical components. The bottom of the processing tool head has an arc grinding wheel for grinding high-steepness optical components.

[0019] As an embodiment, the machining parts (tool heads) of the first machining tool and the second machining tool are arranged angularly symmetrically relative to the central axis of the multi-spindle machining tool head, that is, the two are basically evenly angularly spaced from each other and are fixed to the double-headed hollow spindle with a hydraulic expansion clamp.

[0020] In one embodiment, the twin hollow spindles and torque motors are cylindrical. The inner diameter of the torque motor is equal to the outer diameter of the middle section of the twin hollow spindles. The middle section of the twin hollow spindles is longer than the length of the torque motors. The twin hollow spindles require high rigidity to meet high-speed grinding requirements. The twin hollow spindles are driven by the torque motors.

[0021] As an embodiment, the polishing head used in the polishing component is an airbag polishing head. The airbag polishing head has high material removal efficiency, good stability, high precision, and is suitable for high-steepness optical components.

[0022] In addition, the polishing head of the polishing component is prone to processing interference when facing high-steepness optical elements. The double-headed hollow spindle used in the present invention is combined with a hydraulic expansion clamp to clamp the long-handled polishing head, and when processing high-steepness optical elements, processing interference will not occur while meeting the processing conditions.

[0023] As an embodiment, the grinding processing component includes a grinding spindle box housing, an arc grinding wheel, a grinding spindle, a ball bearing, a sleeve, a grinding wheel front end flange, a grinding wheel rear end flange, a pulley transmission mechanism and a servo motor;

[0024] The arc grinding wheel is provided with rotational power through a pulley transmission mechanism; the front flange of the grinding wheel and the rear flange of the grinding wheel are connected by bolts to fix the arc grinding wheel;

[0025] The pulley transmission mechanism includes a large pulley, a small pulley and a belt, the large pulley is fixed on the motor shaft of the servo motor, the small pulley is fixed on the grinding spindle, the large pulley and the small pulley are connected by a belt, and the upper and lower surfaces are in the same plane; the servo motor is driven and connected to the grinding spindle through the large pulley, the small pulley and the belt;

[0026] The grinding spindle is fixed in the hole of the grinding spindle box housing through a flange and a pair of angular contact ball bearings. The outer diameter of the lower end of the flange is equal to the diameter of the hole, and is fixed to the grinding spindle box housing by bolts.

[0027] The servo motor is placed vertically and fixed on a plate-shaped clamping flange, and the plate-shaped clamping flange and the spindle box housing of the grinding processing part are connected through a supporting point;

[0028] The lower end of the ball bearing is against the sleeve, and below the sleeve is a small pulley. The pulley and the grinding spindle are connected by a key. The upper end of the bearing is a fixed sleeve, and above the fixed sleeve are the front end flange and the rear end flange of the grinding wheel. The grinding spindle is fixed by a locking nut.

[0029] Among them, the belt used for tensioning is a V-belt.

[0030] In the grinding processing parts, the arc grinding wheel transmission part provides rotational power through the pulley transmission mechanism. The grinding spindle is fixed in the spindle box hole through the flange and a pair of angular contact ball bearings. The outer diameter of the lower end of the flange is equal to the diameter of the hole. It is fixed to the spindle box by bolts. The lower end of the bearing is against the sleeve. Below the sleeve is a small pulley. The pulley and the grinding spindle are connected by a key. The upper end of the bearing is a fixed sleeve. Above the fixed sleeve are the front end flange and the rear end flange of the grinding wheel. The locking nut fixes the grinding spindle.

[0031] The sensor device is used to detect the surface quality of the processed workpiece.

[0032] The multi-spindle machining tool head realized by the above scheme has high degrees of freedom, so that machining tools can be replaced more flexibly and machining interference problems caused by machining high-steepness optical elements can be avoided, and the machining needs of high-steepness large-diameter aspherical optical elements can be met. The multi-spindle machining tool head has compact structure, the polishing component can accommodate two machining tools and one spindle, and the grinding machining component can accommodate one machining tool and one spindle, wherein the double-head hollow spindle and the grinding wheel tool spindle are vertically distributed in space.

[0033] The present application utilizes machining tools (cup-shaped grinding wheel, polishing head) to perform precision grinding of the inner surface and the outer surface of high-steepness large-diameter aspherical optical elements, and torque motor is used to provide power. When the torque motor is started, the stator is stationary, and the rotor drives the double-head hollow spindle to rotate. The double-head hollow spindle clamps the machining tool to rotate at a constant speed, and can clamp machining tools of different sizes, such as short-shank cup-shaped grinding wheel, long-shank cup-shaped grinding wheel and polishing head. The short-shank cup-shaped grinding wheel is used for precision grinding of the outer surface of the aspherical large-diameter optical element, the long-shank cup-shaped grinding wheel is used for precision grinding of the inner surface of the aspherical large-diameter optical element, and the polishing head can be used for precision polishing after grinding.

[0034] The present application utilizes a circular-arc grinding wheel to perform grinding of the inner surface of high-steepness large-diameter aspherical optical elements. A servo motor is used to provide power. After the servo motor is started, the motor shaft drives the large pulley to rotate, the large pulley drives the small pulley to rotate through the belt, the small pulley and the grinding spindle end are connected through the key, and the grinding spindle is driven to rotate, so that the circular-arc grinding wheel rotates to perform grinding, and the surface quality of the machined element is improved.

[0035] The grinding machining component of the multi-spindle machining tool head adopts vertical-axis grinding process for high-steepness optical elements, that is, the workpiece spindle and the tool spindle are perpendicular to each other, and a circular-arc grinding wheel is usually used. According to the grinding feed direction, parallel grinding method is adopted, that is, the linear speed of the grinding point of the circular-arc grinding wheel is parallel to the linear speed of the workpiece surface. In the grinding forming principle, it belongs to the grinding of the profile trajectory envelope of the grinding wheel, that is, in the process of grinding spherical surface / aspherical surface by using parallel grinding method, a section of profile on the cross section profile of the grinding wheel participates in grinding. This method improves the effective working area of the grinding wheel, and makes the grinding wheel wear distributed in a wider ring, which is beneficial to weaken the influence of grinding wheel wear on the surface shape error of the grinding surface.

[0036] The multi-spindle machining tool head has machining tools of circular-arc grinding wheel, cup-shaped grinding wheel and polishing head. The function of the circular-arc grinding wheel is rough grinding, which is suitable for concave surface grinding with a depth-width ratio less than 0.5. In order to avoid machining interference, the radius of the circular-arc grinding wheel and the thickness of the transmission part of the circular-arc grinding wheel need to be controlled. The larger the radius, the thinner the thickness, and the less likely the machining interference occurs.

[0037] In order to avoid machining interference during the machining process, the multi-spindle machining tool head adopts the oblique axis grinding method during the grinding process of the long-handled cup grinding wheel. That is, the tool spindle is tilted at a certain angle relative to the workpiece spindle to achieve a larger depth-to-width ratio aspheric grinding. This method is simple to dress and has a variety of feed modes to choose from.

[0038] Compared with the prior art, the technical solution of the present invention has the following beneficial effects:

[0039] 1. The multi-spindle machining tool head of the present invention adopts a modular design, and the machining tools can be flexibly replaced according to the machining process requirements, saving equipment costs.

[0040] 2. The multi-spindle machining tool head of the present invention has a compact structure and high precision. By controlling the size of the machining tool head and the transmission part, the machining interference problem caused by machining high-steepness optical elements can be effectively avoided.

[0041] 3. The rotation center of the machining system of the present invention is located at the center of the three machining tool heads, which can effectively reduce the travel waste and tool collision caused by switching tool heads.

[0042] 4. The processing system of the present invention is a grinding and polishing machine, and grinding and polishing are performed on one machine, which saves the manpower and material costs generated by transporting processing materials, avoids the installation errors caused by secondary clamping, and improves the surface accuracy of optical components to a certain extent.

[0043] In summary, the present invention adopts the above-mentioned scheme, the design of the double-headed hollow spindle, the integrated design of the polishing part and the grinding processing part, and the installation of the processing tool above the pulley transmission mechanism, so that the overall multi-spindle processing tool head is compact in structure, small in size, and has good practicality; and the overall structural design effectively avoids processing interference and is suitable for processing high-steepness optical elements. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] The present invention may be better understood by referring to the following description taken in conjunction with the accompanying drawings, in which the same or similar reference numerals are used throughout the drawings to represent the same or similar components. The accompanying drawings, together with the following detailed description, are incorporated in and form a part of this specification and are used to further illustrate preferred embodiments of the present invention and to explain the principles and advantages of the present invention. In the drawings:

[0045] Figure 1 It is a schematic diagram of the three-dimensional structure of the present invention;

[0046] Figure 2 It is a schematic cross-sectional view of the spindle box of the polishing component;

[0047] Figure 3 It is a schematic diagram of the three-dimensional structure of the spindle box for grinding parts;

[0048] Figure 4 Schematic diagram of the cross section of the arc grinding wheel;

[0049] Figure 5 This is a cross-sectional diagram of the spindle box (motor side) of the grinding component;

[0050] Figure 6 This is a schematic cross-sectional view of the spindle box (pulley device side) of the grinding component;

[0051] Figure 7 This is a schematic diagram of the structure of the polishing head of the present invention;

[0052] Figure 8 Schematic diagram of the parabola at the bottom vertex of the grinding process;

[0053] Figure 9 Schematic diagram of the parabola on the inner surface of the processing component;

[0054] Description of the drawings: 1 sensor device, 2 polishing component spindle box, 3 double-headed hollow spindle, 4 grinding component spindle box, 5 arc grinding wheel, 6 base, 7 bottom cover, 8 grinding component spindle box housing, 9 servo motor shaft, 10 hydraulic expansion clamp, 11 angular contact ball bearing, 12 torque motor, 13 torque motor rotor, 14 torque motor stator, 15 silent polishing spindle box housing, 16 grinding spindle, 17 locking anti-loosening nut, 18 balancing block, 19 grinding wheel front end flange, 20 grinding wheel rear end flange, 21 fixing sleeve, 22 angular contact ball bearing, 23 flange, 24 sleeve, 25 small pulley, 26 belt, 27 pulley transmission mechanism, 28 matching screw, 29 bending groove, 30 support point, 31 joining member, 32 servo motor, 33 plate-shaped clamping flange, 34 base housing, 35 large pulley, T1 first processing tool, T2 second processing tool. DETAILED DESCRIPTION

[0055] Embodiments of the present invention will be described below with reference to the accompanying drawings. Elements and features described in one drawing or one embodiment of the present invention may be combined with elements and features shown in one or more other drawings or embodiments. It should be noted that for the sake of clarity, the drawings and descriptions omit the representation and description of components and processes that are not relevant to the present invention and are known to those of ordinary skill in the art.

[0056] In the description of the present invention, it should be understood that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "back," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," and the like, indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings and are intended solely to facilitate description and simplify the description of the present invention. They are not intended to indicate or imply that the devices or components referred to must have a specific orientation, be constructed, or operate in a specific orientation. Therefore, they should not be construed as limiting the present invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0057] In the description of the present invention, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood in a broad sense. For example, they may refer to fixed, detachable, or integral connections; mechanical or electrical connections; direct or indirect connections through an intermediate medium; and internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on the specific circumstances.

[0058] The multi-spindle machining tool head of the present application is suitable for machining high-steepness and large-aperture aspheric optical elements. The multi-spindle machining tool head has the function of composite grinding, including a polishing part and a grinding part, and the polishing part is installed on the upper end of the grinding part. The multi-spindle machining tool head adopts a modular design, and can flexibly replace machining tools according to the requirements of the machining process. It is suitable for different machining process requirements, and can realize grinding and polishing on one machine, avoiding errors caused by repeated assembly and disassembly. The multi-spindle machining tool head has a compact structure and a small size. The spindles are vertically distributed in space, that is, the polishing part machining tool spindle and the grinding part machining tool spindle are vertically distributed, which can effectively avoid machining interference in the face of high-steepness optical elements. The rotation center designed for the multi-spindle machining system is located at the center of the three machining tool heads and can rotate around the rotation center, effectively reducing the travel waste and tool collision caused by switching tool heads, and has machining flexibility. The multi-spindle machining tool head can flexibly replace machining tools of different sizes, including but not limited to cup grinding wheels, arc grinding wheels and polishing heads, and is suitable for machining high-steepness and large-aperture aspheric optical components of different sizes.

[0059] As a specific example, see Figure 1 As shown, the multi-spindle machining tool head comprises three parts: a polishing component spindle box 2, a grinding component spindle box 4, and a sensor device 1. The sensor device is a surface quality detection sensor.

[0060] like Figure 1As shown, the sensor device 1 for detecting the surface quality of the workpiece after processing is installed on the bottom cover 7.

[0061] like Figure 2 As shown, the polishing component spindle box 2 includes a spindle box housing 15, processing tools T1T2, a torque motor 12, an angular contact ball bearing 11, a hydraulic expansion clamp 10 and a double-headed hollow spindle 3.

[0062] like Figure 2 As shown, the double-ended hollow spindle 3 within the polishing unit's spindle housing 2 can be mounted with corresponding machining tools T1 and T2, such as a cup grinding wheel and a polishing head. The double-ended hollow spindle 3 is a hollow member mounted within the polishing spindle housing 15 via two spaced-apart angular contact ball bearings 11. It is rotatable but immovable axially.

[0063] like Figure 2 As shown, the torque motor 12 in the polishing component spindle box 2 is installed on the double-headed hollow spindle 3 around the rotation axis of the tool to control the speed of the double-headed hollow spindle 3. The rotor 13 of the torque motor 12 is fixedly connected to the double-headed hollow spindle 3, and the stator 14 of the torque motor concentrically around the rotor 13 is fixed on the polishing spindle box housing 15 to prevent them from rotating relative to each other.

[0064] like Figure 2 As shown, hydraulic expansion clamps 10 are provided at both ends of the double-ended hollow spindle 3 to fix the shank ends of the processing tools T1T2 in appropriate positions.

[0065] like Figure 2 As shown, the double-headed hollow spindle 3 fixes the processing tool head T1T2. The processing tool head can be a long-handled cup-shaped grinding wheel for grinding the inside of high-steepness and large-aperture aspheric optical elements. The inside of high-steepness and large-aperture aspheric optical elements has a large steepness, and the long-handled cup-shaped grinding wheel can prevent processing interference while grinding; in addition, the double-headed hollow spindle 3 can also be installed with a short-handled cup-shaped grinding wheel and a polishing head to grind and polish the surface of high-steepness and large-aperture aspheric optical elements.

[0066] like Figures 3 to 6 As shown, the spindle box part of the grinding processing component includes a spindle box housing 6, an arc grinding wheel 5, a locking nut 17, a grinding wheel front end flange 19, a grinding wheel rear end flange 20, a balancing block 18, a grinding spindle 16, a fixing sleeve 22, a flange 23, an angular contact ball bearing 22, a pulley transmission mechanism 27 and a servo motor 32.

[0067] like Figure 3 As shown, the grinding component spindle box 4 and the base part 6 are connected by bolts, and the base part 6 and the bottom cover 7 are connected by bolts.

[0068] like Figure 4As shown, the base portion 6 has a hole at the bottom, and the flange 23 is mounted on the base portion 6 by a threaded connection. The grinding spindle 16 is mounted in the flange 23 through two angular contact ball bearings 22 spaced apart from each other, so that the grinding spindle 16 can rotate but cannot move axially.

[0069] A retaining sleeve 21 is mounted on the top of flange 23 of the grinding spindle 16 to secure the angular contact ball bearing 22, allowing rotation without axial movement. A threaded connection is established between the front and rear flanges 19 and 20 of the grinding wheel. Locknut 17 secures the circular grinding wheel 5 to the grinding spindle 16, preventing axial movement.

[0070] like Figure 4 and Figure 6 As shown, the pulley drive mechanism 27 provides power for the arc grinding wheel 5. The pulley drive mechanism 27 includes a servo motor 32, a large pulley 35, a small pulley 25, and a belt 26. The servo motor 32 provides power to the large pulley 35, causing the large pulley 35 to drive the belt 26 to rotate, thereby driving the small pulley 25 to rotate, achieving speed increase and torque reduction. The belt drive device 27 is parallel to the grinding spindle 16 and is keyed to the end of the grinding spindle 16 through the belt 26 and the small pulley 25 to rotate the arc grinding wheel 5.

[0071] like Figure 4 As shown, the belt drive device 27 is arranged parallel to the grinding spindle 16 and is driven and connected to the grinding spindle 16 via the belt 26, so as to be used for the grinding spindle 16 to drive the circular arc grinding wheel 5 to rotate. The belt 26 and the small pulley 25 that cooperates with the belt 26 are fixed to the end of the grinding spindle 16 through a key connection. The grinding spindle 16 passes through the grinding processing component spindle box housing 8 and the flange 23 to be connected to the circular arc grinding wheel 5. The belt 26 and the small pulley 25 cooperate. The pulley 25 is mounted on the motor shaft 9 of the servo motor, and the servo motor shaft 9 is fixed in the circular arc grinding spindle housing 8.

[0072] like Figure 5 and Figure 6 As shown, a servo motor 32 is arranged to be rotatable relative to the grinding spindle 16 for tensioning the belt 26. The servo motor 32 is bolted to a plate-shaped clamping flange 33, which is arranged on the side of the base part 6 facing away from the bottom cover 7. The plate-shaped clamping flange 33 is arranged to be rotatable relative to the base part 6 about a support point 30 on the base part 6. The plate-shaped clamping flange 33 can also be rotated by means of a curved groove 29 and a mating screw 28 fixed to the base part 6. In this case, the servo motor shaft 9 passes through a large cutout in the base part 6, so that a large pulley 35 and the servo motor shaft 9 can be connected by a key, with the large pulley 35 resting on the base part 6.

[0073] likeFigure 5 As shown, the coupling member 31 is laterally coupled to the plate-shaped clamping flange 33 between the servo motor shaft 9 and the support point 30. The coupling member 31 can be axially adjusted relative to the base by a handle, and the handle is threadedly connected relative to the base along the axial axis of the base. Through the axial adjustment of the coupling member, the plate-shaped clamping flange 33 can be rotated around the support point 30, thereby tensioning the belt 26.

[0074] The present invention is applicable to aspheric optical elements with high steepness. Affected by the radius of the grinding wheel 5 and the vertical thickness of the base 6, the base 6 and the bottom cover 7 may collide with the optical element during the grinding of the high steepness optical element by the grinding wheel, resulting in processing interference. Therefore, in order to prevent processing interference, within a reasonable processing range, the larger the radius of the grinding wheel 5, the better, and the smaller the thickness of the base 6, the better.

[0075] The size parameters of the high-steepness aspheric optical element applicable to the present invention are a thickness of 120 mm and an aperture of 450 mm.

[0076] The radius of the grinding wheel 5 of the present invention is 75 mm, and the thickness of the base 6 is 34 mm. A parabola is drawn with the bottom grinding point of the grinding wheel 4 and the vertex of the bottom cover 7.

[0077] like Figure 7 As shown, the grinding point of the grinding wheel 5 is taken as the origin B, the coordinate is (0, 0), the coordinate value of the vertex A of the bottom cover 7 is (-55, 55), and the general equation of the parabola with the opening facing upward is as follows:

[0078] X 2 =2py(p>0) (1)

[0079] Formula (1) can be transformed into:

[0080]

[0081] Substituting the coordinates of point A and point B into equation (2), the resulting parabola equation is:

[0082] Right now That is, the focal coordinates are

[0083] like Figure 8 As shown in the figure, the vertex N of the parabola of the processing surface of the high-steepness optical element is taken as the zero point of the coordinate axis, and the coordinate value of the vertex M is (200,95). The equation of the parabola of the processing surface of the optical element can be obtained as follows:

[0084]

[0085] The formula for calculating curvature is:

[0086]

[0087] The formula for the radius of curvature is

[0088]

[0089] According to the calculation, the curvature radius of formula (3) is:

[0090]

[0091] According to the calculation, the curvature radius of formula (4) is:

[0092]

[0093] To prevent machining interference, equations (3) and (4) are made tangent. Equation (3) is always above equation (4) as it moves from the bottom zero point to the vertex of equation (4), and has only one tangent point of contact with equation (4). Calculations show that the radius of curvature of the parabola formed by the grinding wheel grinding point and the vertex of the bottom cover is smaller than the minimum radius of curvature of all points and directions on the inner surface of the aspheric surface.

[0094] The operating method of the multi-spindle machining tool head of the present invention is as follows:

[0095] The present invention is suitable for processing aspheric optical elements of different sizes, high steepness, and large aperture. When in use, the cup-shaped grinding wheel is first installed on both ends of the double hollow spindle using a hydraulic expansion clamp. When processing the surface of the original workpiece, the servo motor is started, and the motor shaft drives the large pulley to rotate. The large pulley rotates the small pulley through the belt. The small pulley is connected to the end of the grinding spindle by a key, driving the grinding spindle to rotate, thereby rotating the arc grinding wheel for grinding. After processing is completed, the processing tool head is rotated, and the end with the cup-shaped grinding wheel is aligned with the processing element for fine grinding. During fine grinding, the torque motor is started, wherein the torque motor stator is stationary, and the rotor drives the double hollow spindle to rotate, thereby driving the processing tool to rotate the outer surface of the grinding element. After grinding is completed, the cup-shaped grinding wheel can be removed from both ends of the double hollow spindle and replaced with a polishing head to polish the surface of the processing original workpiece.

[0096] It should be emphasized that the term "include / comprises" when used herein refers to the existence of features, elements, steps or components, but does not exclude the existence or addition of one or more other features, elements, steps or components.

[0097] Although the present invention has been disclosed above through the description of specific embodiments of the present invention, it should be understood that all the above embodiments and examples are illustrative rather than restrictive. Those skilled in the art may devise various modifications, improvements, or equivalents of the present invention within the spirit and scope of the appended claims. Such modifications, improvements, or equivalents should also be considered to be within the scope of protection of the present invention.

Claims

1. A multi-spindle machining tool head for machining high-steepness optical components, characterized by: The sensor device comprises a sensor device, a polishing component and a grinding component, wherein the polishing component is mounted on the upper part of the grinding component, and the sensor device is mounted on the upper part of the polishing component; Wherein, the polishing component includes a polishing spindle box housing, a first processing tool, a second processing tool, a torque motor, an angular contact ball bearing, a hydraulic expansion clamp and a double-headed hollow spindle; the double-headed hollow spindle is a hollow component, which is installed in the polishing spindle box housing through two angular contact ball bearings separated from each other, and the double-headed hollow spindle can rotate but cannot move axially; the torque motor is arranged in the polishing spindle box housing, and is installed on the double-headed hollow spindle around the rotation axis of the tool to control the speed of the double-headed hollow spindle; the rotor of the torque motor is fixedly connected to the double-headed hollow spindle, and the stator of the torque motor concentrically surrounds the rotor and is fixed to the polishing spindle box housing to prevent them from rotating relative to each other; the double-headed hollow spindle extends outward from the polishing spindle box housing at both ends, and the hydraulic expansion clamp is arranged on both ends of the double-headed hollow spindle for fixing the shank ends of the first processing tool and the second processing tool; The grinding components include a grinding spindle for clamping the optical element, a circular arc grinding wheel for grinding the optical element, and a pulley transmission device for providing power to the circular arc grinding wheel; The double-headed hollow spindle of the polishing part and the grinding spindle of the grinding part are arranged vertically; The rotation center of the multi-spindle machining tool head is located at the center of the first machining tool, the second machining tool and the arc grinding wheel, so that the multi-spindle machining tool head rotates around the rotation center as a whole.

2. The multi-spindle machining tool head for machining high-steepness optical components according to claim 1, characterized in that: The first processing tool and the second processing tool are arc grinding wheels, cup grinding wheels, polishing heads or long-handled cup grinding wheels.

3. The multi-spindle machining tool head for machining high-steepness optical components according to claim 1, characterized in that: The first machining tool and the second machining tool are arranged in angular symmetry with respect to a central axis of the multi-spindle machining tool head.

4. The multi-spindle machining tool head for machining high-steepness optical components according to claim 1, characterized in that: The double-headed hollow main shaft and the torque motor are cylindrical, the inner diameter of the torque motor is equal to the outer diameter of the middle part of the double-headed hollow main shaft, and the length of the middle part of the double-headed hollow main shaft should be longer than the length of the torque motor.

5. The multi-spindle machining tool head for machining high-steepness optical components according to claim 1, characterized in that: The grinding processing components include a grinding spindle box housing, an arc grinding wheel, a grinding spindle, a ball bearing, a sleeve, a grinding wheel front end flange, a grinding wheel rear end flange, a pulley transmission mechanism and a motor; The arc grinding wheel is provided with rotational power through a pulley transmission mechanism; the front flange of the grinding wheel and the rear flange of the grinding wheel are connected by bolts to fix the arc grinding wheel; The pulley transmission mechanism includes a servo motor, a large pulley, a small pulley and a belt, the large pulley is fixed on the motor shaft of the servo motor, the small pulley is fixed on the grinding spindle, the large pulley and the small pulley are connected by a belt, and the upper and lower surfaces are in the same plane; the servo motor is driven and connected to the grinding spindle through the large pulley, the small pulley and the belt; The grinding spindle is fixed in the hole of the grinding spindle box housing through a flange and a pair of angular contact ball bearings. The outer diameter of the lower end of the flange is equal to the diameter of the hole, and is fixed to the grinding spindle box housing by bolts. The motor is placed vertically and fixed on the plate-shaped clamping flange, and the plate-shaped clamping flange and the spindle box housing of the grinding part are connected through supporting points; The lower end of the ball bearing is against the sleeve, and below the sleeve is a small pulley. The pulley and the grinding spindle are connected by a key. The upper end of the bearing is a fixed sleeve, and above the fixed sleeve are the front end flange and the rear end flange of the grinding wheel. The grinding spindle is fixed by a locking nut.

6. The multi-spindle machining tool head for machining high-steepness optical components according to claim 5, characterized in that: The belt used is a V-belt.

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