JP3787457B2 - Polishing tool - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a polishing tool used in a polishing apparatus for polishing an optical element such as a lens or a mirror, and more particularly to a polishing tool having a smaller diameter than a processing surface used when polishing an aspherical shape of an optical element. Is.
[0002]
[Prior art]
In polishing processing to precisely finish the surface of optical elements such as spherical and aspherical lenses and mirrors, the surface roughness of optical elements is improved and the performance of optical elements is significantly reduced. For the purpose of smoothing the swell (ripple) of the period, a polishing tool using a pitch as a material for a polisher is often used.
[0003]
A conventional polishing tool for polishing the aspherical shape of these optical elements is configured as shown in FIG. 20, and a polisher 102 using a pitch having a plurality of convex portions on the polishing surface is used as a tool base. It is directly affixed to an elastic body 103 such as rubber supported on a table (tool shank) 104. This elastic body 103 is for allowing the polisher 102 of the polishing tool 101 to follow any location of the aspherical shape, and smoothes the undulations (ripple) of the short period on the aspherical surface. As the polishing tool used for the purpose, a tool formed to have a smaller diameter than the processing surface of the workpiece is used.
[0004]
[Problems to be solved by the invention]
When polishing an optical element with a large amount of aspherical surface, the curvature of the surface to be processed varies greatly from place to place, so the required amount of deformation of the tool shape increases. However, in conventional polishing tools, the polisher is integrated with the elastic body. If the polisher is hard, the amount of deformation of the polisher is restricted and the elastic body cannot move freely, ensuring a large amount of deformation. It was difficult. That is, when the required amount of deformation increases, the tool is rigidly strong against the amount of deformation, and depending on the aspherical shape of the work surface, it cannot be deformed following the shape of the surface, and the contact state in the tool is It becomes non-uniform depending on the location, the pressure distribution in the tool varies depending on the location of the work surface, and there is a drawback that the shape after polishing is deteriorated.
[0005]
For this reason, in order to ensure that the polisher surface of the polishing tool conforms to the aspherical shape, the hardness of the elastic body such as rubber is lowered or the thickness of the elastic body is increased so that the deformation can be increased. There is a need to.
[0006]
However, there is a fact that the undulation of a short period on the surface to be processed becomes difficult to smooth as the hardness of the elastic body serving as a back-up for the polisher decreases. In other words, the phenomenon that the tool does not come into uniform contact with the smoothed waviness top occurs and the smoothing efficiency of waviness is poor. In order to follow the shape change of the aspherical surface, it is conceivable to reduce the tool diameter. However, the smaller the tool diameter, the lower the swell smoothing efficiency and the longer the polishing time. In addition to the disadvantages described above, the waviness cannot be smoothed depending on the smoothed waviness period. In other words, in order to smooth the swell efficiently, the tool diameter cannot be made too small.
[0007]
Further, a polisher made of pitch used in a conventional polishing tool has a disadvantage that it is brittle and easily cracks. In particular, in a configuration like the conventional polishing tool described above, the pitch polisher is rubber or the like. Therefore, there is a problem in that stress is applied to the pitch polisher due to deformation of the elastic body due to movement during polishing, and the polisher is destroyed during polishing. This phenomenon is particularly affected by the lateral movement (tool movement direction) during polishing, that is, the shearing direction stress.
[0008]
In order to reduce such deformation in the lateral direction, measures such as increasing the hardness of the elastic body or reducing the thickness of the elastic body to reduce deformation and distortion of the elastic body can be considered, In this case, as described above, since the amount of deformation of the elastic body is reduced, it is difficult to make the polisher follow the aspherical shape of the workpiece.
[0009]
Thus, when polishing an aspherical shape, the elastic body portion of the polishing tool must satisfy contradictory characteristics.
[0010]
Therefore, the present invention has been made in view of the unsolved problems of the prior art as described above, and without polishing or breaking the polisher when polishing an aspherical shape having a large curvature change, It is an object of the present invention to provide a polishing tool that can follow a change in curvature of a surface to be processed and can efficiently smooth a swell of a short period.
[0011]
[Means for Solving the Problems]
To achieve the above object, the polishing tool of the present invention is a polishing tool comprising a polisher, an elastic body that holds the polisher, and a cylindrical tool base to which the elastic body that holds the polisher is attached. Between the polisher and the elastic body, it has a rigidity that is deformable in a direction perpendicular to the surface but difficult to deform in the same direction as the surface. Lattice A plate-like member is interposed, the polisher is composed of a plurality of independent polisher pieces, and the elastic body is composed of a plurality of independent elastic pieces, and each of the polisher pieces and the elastic pieces are Said Lattice It is attached to each part facing each other with a plate-like member in between In addition, a fall prevention wall for preventing the fall in a direction perpendicular to the load direction is provided between the adjacent elastic parts. It is characterized by that.
[0012]
[Action]
According to the polishing tool of the present invention, when polishing a work surface such as an aspherical surface having a large curvature change, the polished surface of the polisher has a smooth shape even if the work surface has a large change in curvature. Thus, the entire polished surface of the polisher uniformly hits the surface to be processed, and the entire surface to be processed can be uniformly polished without causing shape deterioration. Furthermore, the polished surface of the polisher can efficiently smooth the undulation without following the irregular shape of the undulation of a short period, and can polish the aspherical shape of an optical element such as a lens or a mirror with high accuracy. it can. In particular, by setting the tool diameter to at least twice the waviness period, it is possible to smooth the waviness easily and more efficiently.
[0013]
Also, the polisher is composed of a plurality of independent polisher pieces and the elastic body is also composed of a plurality of independent elastic pieces, which can be easily deformed in the direction perpendicular to the surface, but in the same direction as the surface Has rigidity that is difficult to deform Lattice By attaching to the plate-like member, it is possible to increase the amount of deformation of the polished surface of the polisher, and to quickly and smoothly follow a large shape change of the work surface. For this reason, since the polished surface of the polisher deforms following the shape of the surface to be processed, the entire surface can be uniformly contacted with the surface to be processed, and uniform polishing can be performed. The swell can also be smoothed efficiently.
[0014]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described with reference to the drawings.
[0015]
1 is a cross-sectional view of a polishing tool of a first reference example, FIG. 2 is a plan view of a leaf spring portion used in the polishing tool of the first reference example, and FIG. 3 is a polishing tool of the first reference example. It is sectional drawing which shows this modification.
[0016]
As shown in FIG. 1, the polishing tool 1 of the present reference example includes a polisher 2, a thin plate member 3, an elastic body 4, and a tool base (tool shank) 5. The tool base 5 is made of metal or the like. Thus, it is formed in a cylindrical shape having a sufficiently small diameter with respect to the work surface of the work piece, and the tool diameter is set to φ20 mm. On the surface of the tool base 5 facing the workpiece, an elastic body 4 made of polychloroprene rubber having a thickness of 2 mm, and a leaf spring-like metal having a thickness of about 0.05 mm as a thin plate member A plate (hereinafter, also simply referred to as a leaf spring) 3 and a polisher 2 formed with a pitch of 0.5 mm in thickness are sequentially attached.
[0017]
As shown in FIG. 2, the leaf spring 3 as a thin plate member is formed of a central segment 3a and six peripheral segments 3b surrounding the central segment 3a, and the central segment 3a and the six peripheral segments 3b are thin. The six peripheral segments 3b are connected by a strip 3d in the circumferential direction, and adjacent peripheral segments are connected by a thin strip 3d in the circumferential direction. The central segment 3a and the peripheral segment 3b, and the radial strip 3c and the circumferential strip 3d are produced by etching a thin plate having a diameter of 20 mm. With this shape, the leaf spring 3 can be easily deformed in the vertical direction (perpendicular to the leaf spring surface) and torsion, but in the lateral direction (the same direction as the leaf spring surface) and in the circumferential direction. Is difficult to deform. Moreover, as a material of the leaf | plate spring 3, SUS, spring steel, phosphor bronze, etc. can be used, The thickness is desirably about 0.03-0.2 mm.
[0018]
The pitch of the polisher 2 is a polisher having a shape pattern composed of a plurality of convex portions, and a transfer plate corresponding to the convex pattern is sandwiched between the transfer mold and the tool, and the pitch is adjusted to the tool base to which the pitch is attached. Is heated to its softening temperature, and the pitch is transferred to the tool base 5 side. At this time, an elastic body 4 such as rubber is baked in advance on the tool base 5 side, and a leaf spring 3 having a shape as shown in FIG. 2 is stuck on the elastic body 4 with an adhesive. ing. In order to further improve the reliability of bonding, a liquid pitch previously dissolved in a solvent may be uniformly applied to the pitch forming surface of the leaf spring 3, and the pitch may be transferred and molded thereon.
[0019]
The polishing tool 1 of this reference example is configured as described above, and is flexible between the polisher 2 and the elastic body 4 in the axial direction (direction in which the tool is pressed against the surface to be polished) and in the lateral direction (polishing). By interposing a leaf spring (metal plate) 3 as a thin plate member having strength (rigidity) in the direction of movement of the pitch, there is no fear that the pitch polisher is destroyed by shearing force during polishing, and the curvature is Even when polishing an aspherical surface that varies greatly, the polisher can be brought into uniform contact with the surface to be processed.
[0020]
That is, as shown in FIGS. 4A and 4B, the surface L to be processed is an aspherical surface, and the surface L to be processed whose curvature is partially changed at the place to be polished is used. When polishing using the polishing tool 1 of the reference example, since the leaf spring 3 has almost no rigidity in the axial direction, the elastic body 4 plays a sufficient role as it is when the polisher is directly formed on the elastic body. Even a light load deforms along the shape of the work surface. As a result, the polished surface can smoothly follow the shape of the processed surface L even if the processed surface L has a variable curvature, and the entire polished surface of the polished surface uniformly hits the processed surface L so that the entire surface is covered. Uniform polishing is possible. Thereby, even if a surface whose curvature of the surface to be processed L varies depending on the location, the shape accuracy after polishing can be finished with high accuracy. Also, as shown in FIG. 4C, the polisher 2 is a plate spring as a plate-like member for undulation (ripple) having a period (pitch) P that is ½ or less of the tool diameter D. By the action of 3 and the elastic body 4, the undulation can be smoothed without following the irregular shape of the undulation.
[0021]
During actual polishing, the polishing tool was swung by a rocking mechanism (not shown), and the entire surface to be processed L was scanned by a scanning locus as shown in FIG. . Here, the same result was obtained for the revolving motion of the polishing tool. Further, it is possible to perform polishing in combination with the revolution and rotation of the polishing tool so that the polishing rate of the entire contact surface of the polisher is constant.
[0022]
When polishing is performed in this way, a relative speed is generated between the work surface L and the polisher (pitch), and a shearing force is generated accordingly, and the elastic body made of the polychloroprene rubber is caused by the shearing force. 3 is greatly deformed in the lateral direction. However, a leaf spring 3 is interposed at a boundary portion between the polisher 2 and the elastic body 4 having a pitch, and the leaf spring 3 holds a force for deforming the polisher 2. For this reason, the polisher 2 is not greatly deformed, and cracking of the polisher (pitch) 2 can be prevented.
[0023]
Moreover, it replaces with the leaf | plate spring 3 as a thin plate-shaped member in the reference example mentioned above, As shown in FIG. 3, the polyurethane foam sheet 3x about 0.2 mm-1 mm in thickness can also be used. The transverse shear force generated during the polishing process is received by the tensile strength of the polyurethane foam sheet 3x.
[0024]
Also in the case of this modification, the elastic body 4 such as rubber is baked in advance on the tool base 5 side, and a polyurethane foam sheet 3x having a diameter of 20 mm and a thickness of 0.5 mm is stuck on the elastic body 4 with an adhesive. Then, the polisher 2 is formed similarly to the reference example described above.
[0025]
The plate-like member 3x interposed between the polisher 2 and the elastic body 4 is not limited to a polyurethane foam sheet, and has characteristics corresponding to it (tensile strength, flexibility, adhesive, pitch, and the like). Others may be used as long as they have compatibility with each other.
[0026]
As described above, in the reference examples shown in FIGS. 1 and 3, the pitch between the polishing tool and the elastic body is flexible in the axial direction (direction in which the tool is pressed against the surface to be polished) and in the lateral direction (polishing). (Direction of motion) is a structure that sandwiches a leaf spring or sheet with strength (rigidity), so there is no fear that the polisher will be destroyed by shearing force during polishing, and the curvature will change locally Even when polishing an aspherical workpiece, the workpiece can smoothly follow the aspherical shape of the workpiece surface as described above, and the workpiece surface can be uniformly polished. Furthermore, for a waviness having a period (pitch) of ½ or less of the tool diameter, the polished surface can smooth the waviness without following the irregular shape of the waviness.
[0027]
next, Second of reference An example polishing tool will be described with reference to FIGS.
[0028]
(A) in FIG. Second of reference It is sectional drawing of the polishing tool of an example, The same (b) is an end elevation of the polisher in the polishing tool, (a) And (b) of FIG. 2 of reference It is a top view of the plate-shaped member which can be used for the polishing tool of an example, (a) of FIG. 2 of reference It is sectional drawing which shows the modification of the polishing tool of an example, The same (b) is an end elevation of the polisher of the polishing tool.
[0029]
In (a) and (b) of FIG. reference An example polishing tool 11 includes a polisher 12, a thin plate member (metal plate such as a leaf spring) 13, an elastic body 14, and a tool base (tool shank) 15. The tool base 15 is made of a magnetic material such as metal. It is preferable that the body is formed in a cylindrical shape having a sufficiently small diameter with respect to the work surface of the work piece, and further has a diameter that is twice or more the period (pitch) of the removed swell on the work surface. (See FIG. 9 (c)) For example, when the waviness period is 10 mm, the tool diameter is set to φ20 mm or more.
[0030]
Book reference For the polisher 12 used in the polishing tool of the example, a pitch formed with a thickness of 0.5 mm to 1 mm is used. As shown in FIG. The plurality of independent polisher pieces 12a, that is, the polisher pieces 12a divided into six pieces corresponding to a shape separated by a plurality of lines extending radially from the central portion. The elastic body 14 made of polychloroprene rubber having a thickness of 3 mm is also formed on six elastic pieces 14 a (not shown) that are divided and arranged similarly to the polisher 12.
[0031]
As the plate spring 13 as a plate member sandwiched between the polisher 12 and the elastic body 14, a SUS plate spring having a thickness of about 0.05 mm is used. The plurality of divided pieces of the polisher 12a and the elastic piece 14a are not moved completely independently by the leaf spring 13, but are configured so that the polisher is integrated, that is, acts as one tool. is doing.
[0032]
Book configured as above reference In the example, by dividing the polisher 12 and the elastic body 14 into a plurality of parts, the amount of deformation can be increased as compared with a conventional polishing tool, and as shown in FIGS. 9A and 9B, Even if the polished surface has a different curvature, the polished surface can smoothly follow the shape of the processed surface. Then, by connecting the plurality of polisher pieces 12a and the elastic part pieces 14a with the leaf spring 13, the plurality of polisher pieces 12a do not move independently of each other, and the plurality of polisher pieces 12a are integrated. Act. For this reason, as shown in FIG. 9 (c), the polisher 12 acts on the undulation integrally with the undulation having a period (pitch) P of 1/2 or less of the tool diameter D. The waviness can be smoothed without reducing the smoothing efficiency of the waviness as compared with the conventional example in which the polisher 12 is integrated. In this way, even when a surface having a large aspheric amount and a curvature of the surface to be processed that varies greatly depending on the location is polished, the shape does not change and the waviness can be smoothed.
[0033]
Further, as the material of the polisher 12, foamed urethane rubber or silicon rubber can be used in addition to the pitch, and as the elastic body, sponge-like rubber can be used in addition to polychloroprene rubber and silicon rubber.
[0034]
Further, as the material of the plate spring 13 as the plate-like member, SUS, spring steel, phosphor bronze, or the like can be used, and as shown in FIG. It is also possible to make the shape sufficiently changeable.
[0035]
That is, the leaf spring 13 is divided into six segments 13a so as to correspond to a plurality of separated pieces of polisher 12a, as shown in FIGS. 7A and 7B, and these segments 13a. Is divided into a through hole 13b provided in the center and a plurality of slits 13c extending radially from the through hole 13b into a portion corresponding to a portion where the polisher small piece or the elastic piece is not located, as shown in FIG. Each segment 13a of the leaf spring 13 shown in FIG. 5 is connected around the through hole 13b in the center and at the outer periphery located at the end of the slit 13c, and each of the leaf springs 13 shown in FIG. The segments 13a are formed so as to be connected to each other at a part of the intermediate portion of the slit 13c formed radially from the through hole 13b in the central portion. By adopting such a shape, the leaf spring 13 can be easily deformed in the vertical direction (perpendicular to the leaf spring surface) but deformed in the lateral direction (the same direction as the leaf spring surface). It becomes a difficult structure, and it is possible to quickly and smoothly follow large changes in the shape of the work surface.
[0036]
The shape of the polisher can also be configured as shown in FIGS. 8A and 8B. That is, it can be separated in the circumferential direction as well as in the radial direction, and the number of independent polisher pieces 12xa can be increased to more smoothly follow a large shape change of the aspherical surface. At this time, the size of the polisher 12x was set to a diameter of about twice the waviness period as in the above-described example, and was set to φ20 mm. The elastic body 14x can also be separated into the same shape as the polisher piece 12xa, and the leaf spring 13x can also be divided into segments similar to the polisher piece 12xa of the polisher 12x.
[0037]
In actual polishing using the polishing tool configured as described above, as shown in FIG. 5, the polishing tool scans the entire surface to be processed while swinging by a swing mechanism (not shown). The uniform removal was performed.
[0038]
As described above, the book illustrated in FIGS. reference The polishing tool of the example has elastic bodies 14 and 14x each having a smaller diameter than a work surface such as a mirror or a lens, and a plurality of independent elastic pieces on a cylindrical tool base 15. The elastic body Polishers comprising plate springs 13 and 13x as disk-like plate members on 14 and 14x, and a plurality of independent polisher pieces 12a and 12xa corresponding to the positions of the elastic bodies 14 and 14x on the plate springs 13 and 13x. 12, 12x. For this reason, when polishing the work surface with the polishing tool 11, the polisher polished surface follows the shape of the work surface even when polishing the work surface with a large amount of aspheric surface and a large curvature change depending on the location. Deform. As a result, the entire surface of the workpiece can be uniformly hit, and uniform polishing can be performed, and shape change due to polishing does not occur. Furthermore, the waviness of 1/2 or less of the target tool diameter can be smoothed by a tool having a diameter of twice or more the period of the removed waviness on the work surface. Ie book reference According to the example polishing tool, it becomes possible to polish an optical element such as an aspheric lens with high accuracy.
[0039]
Next, the first of the present invention 1 With reference to FIGS. 10 to 15, the polishing tool of the embodiment of FIG. Along with reference examples explain.
[0040]
(A) in FIG. Third of reference It is sectional drawing of the example polishing tool, The same (b) is a bottom view of the polishing tool.
[0041]
In (a) and (b) of FIG. reference The polishing tool 21 of the example includes a polisher 22 composed of a plurality of independent polisher pieces 22a, a plurality of holding portions 23a that respectively hold the plurality of polisher pieces 22a, and a grid-like connection that connects these holding portions 23a vertically and horizontally. It comprises a plate-like member 23 made up of a portion 23b, an elastic body 24 made up of a plurality of independent elastic pieces 24a, and a tool base (tool shank) 25. The tool base 25 is preferably made of a magnetic material such as a metal, and is formed in a cylindrical shape having a sufficiently small diameter with respect to the surface to be processed of the workpiece, and the tool diameter is φ30 mm.
[0042]
Book reference As the polisher small piece 22a constituting the polisher 22 in the polishing tool of the example, a pitch formed in a cylindrical shape having a diameter of φ4 mm and a thickness of 0.5 mm to 1 mm is used. Are attached to the holding portions 23a and aligned in a grid pattern. In addition to the pitch, polyurethane foam or the like can be used as the material of the polisher piece 22a constituting the polisher 22.
[0043]
The plate-like member 23 that holds the polisher piece 22a is formed of a plate spring such as SUS, spring steel, or phosphor bronze having a thickness of 0.05 mm, and a plurality of holding portions 23a that respectively hold the plurality of polisher pieces 22a and these The holding portion 23a includes a mesh-like connecting portion 23b that connects the holding portion 23a vertically and horizontally, and is formed in a lattice shape.
[0044]
The plurality of elastic pieces 24a constituting the elastic body 24 are made of polychloroprene rubber, silicon rubber, sponge rubber, or the like having a thickness of 3 mm, and have the same shape as the polisher small piece 22a and a diameter of about φ4 mm. Then, they are respectively attached at positions corresponding to the polisher pieces 22a with the plate-like member 23 interposed therebetween, and are respectively attached to the tool base 25.
[0045]
Thus, the polisher 22 consisting of a plurality of polisher pieces 22a and the elastic body 24 consisting of a plurality of elastic pieces 24a are respectively attached to the grid-like plate-like member 23 sandwiched between them. It is attached to the tool base 25. Accordingly, the plurality of polisher pieces 22a do not move completely independently of each other, and the plurality of polisher pieces 22a are configured so as to act as an integral polisher, that is, as a single φ30 mm tool. ing.
[0046]
Book configured as above reference In the polishing tool 21 of the example, by dividing the polisher 22 and the elastic body 23 into a plurality of parts, the amount of deformation can be increased compared to the conventional polishing tool, and the polished surface of the polisher is as shown in FIG. Even if it is a work surface L having greatly different curvatures, the shape of the work surface L can be smoothly followed. In other words, even when polishing a surface with a large amount of aspherical surface and the curvature of the workpiece surface varies greatly depending on the location, the polisher polishing surface uniformly strikes the entire processing surface and the pressure distribution in the polishing surface is uniform. Therefore, the shape change after polishing is small and polishing can be performed with high accuracy. Then, by connecting the plurality of polisher pieces 22a and the elastic part pieces 23a by the lattice-like plate-like member 23, the plurality of polisher pieces 22a do not move independently, and the plurality of polisher pieces 22a are integrated. Therefore, for the undulation having a period (pitch) of 1/2 or less of the tool diameter, that is, 15 mm or less, the polisher 22 acts on the undulation integrally. However, even if it is compared with the conventional polishing tool with which waviness is integrated, waviness can be smoothed efficiently without lowering the smoothing efficiency of waviness.
[0047]
Book reference In actual polishing using the polishing tool in the example, as shown in FIG. 5, uniform removal is performed by scanning the entire surface of the workpiece while the polishing tool is swung by a swing mechanism (not shown). Went.
[0048]
The first of the present invention Example of Polishing tools In FIG. Show. The polishing tool of this example is The fall prevention wall 26 is provided between the adjacent elastic parts 24a so that the plurality of elastic parts 24a constituting the elastic body 24 move only in the polishing load direction, that is, in order to restrict lateral movement. Provided on stand 25 Have The Other configurations are shown in FIG. Third reference It is the same as that of an example, and the same code | symbol is attached | subjected to the same member.
[0049]
These fall prevention walls 26 restrict the movement of the elastic piece 24a in the direction perpendicular to the load direction. Thereby, the polishing pressure at the time of the polishing process is not released in the lateral direction, and the polishing pressure can be efficiently applied to the surface to be processed.
[0050]
Furthermore, as illustrated in FIG. 13, a coil spring 24 x can be used as a plurality of elastic pieces constituting the elastic body 24. In this example, a coil spring 24x having a length of 3 mm in a steady state is used. Other configurations are shown in FIG. Third reference It is the same as that of an example, and the same code | symbol is attached | subjected to the same member.
[0051]
Furthermore, as a modification of the elastic body, cylinder means as shown in FIG. 14 may be used. That is, in the tool shank 25x, pressure chambers 28 communicating with a plurality of cylinder holes 27 formed on the surface thereof are formed, and movable bodies 29 that can be moved independently are inserted into the plurality of cylinder holes 27, respectively. The movable body 29 is pressurized downward in the figure by introducing pressurized air into the pressure chamber 28. These movable bodies 29 are arranged corresponding to the lattice-like plate-like members 23 and the polisher pieces 22a arranged in the same manner as in the above-described embodiment, and each movable body 29 is elastic in the above-described embodiment. It performs the same function as the pieces 24a and 24x.
[0052]
As a modification of the plate-like member 23, as shown in FIG. 15, a lattice-like shape in which the holding portion 23xa holding the polisher piece 22a constituting the polisher 22 is made thicker than the other connecting portions 23xb. It can be a plate-like member 23x. For example, the thickness of the holding portion 23xa of the polisher piece 22a is 0.1 mm, and the thickness of the other connecting portion 23xb is 0.05 mm. Thus, by making the holding portion 23xa for holding the polisher piece 22a thicker than the other portions 23xb, the rigidity of the individual polisher piece 22a can be increased, and smoothing such as swell can be facilitated. Become. In addition, since the other connecting portions 23xb are thin, it goes without saying that a large aspherical shape can be copied smoothly.
[0053]
As described above, in the embodiment shown in FIGS. 10 and 12 to 15 and the modifications thereof, the surface to be processed such as a mirror or a lens is polished using a polishing tool having a smaller diameter than the surface to be processed. In particular, when polishing a shape having a large amount of aspherical surface and a large curvature change depending on the location, it is composed of an elastic body composed of a plurality of independent elastic pieces and a plurality of independent polisher pieces on a disk-shaped tool base. Even when a workpiece having a large aspheric surface is polished with a tool having a polisher and a lattice plate member interposed between the elastic piece and the small piece of polisher. Since the surface is deformed following the shape of the surface, the entire surface of the polishing tool hits the surface to be processed uniformly, and uniform polishing can be performed without causing a shape change due to the polishing.
[0054]
In addition, by setting the polishing tool to a tool diameter that is at least twice the period of the removed waviness on the aspherical surface, even if the amount of aspherical surface is large, it is possible to follow the shape, thereby smoothing the waviness efficiently. Can be That is, according to the polishing tool of the present embodiment, it is possible to accurately polish an optical element such as an aspheric lens.
[0055]
Next 4 The polishing tool of the reference example will be described with reference to FIGS. 16 and 17.
[0056]
In FIG. 16, the polishing tool 31 of this reference example is composed of a pitch 32 as a polisher, a ring-shaped elastic body 34 and a tool base 35, and the tool base 35 is against the workpiece surface of the workpiece. A cylindrical shape having a small diameter, preferably made of a magnetic material such as metal, and the tool diameter is 20 mm. A protrusion 36 having a diameter of 10 mm and a height of 2 mm is provided at the center of the surface of the tool base 35 facing the workpiece, which is concentric with the outer diameter of the tool base 35. The ring-shaped elastic body 34 is attached so as to be fitted to the protruding portion 36 of the tool base 35, is at least 1 mm thicker than the protruding amount of the protruding portion 36, has a thickness of about 3 mm, and has a JIS hardness of 15 to 30 A (pitch) polisher 32 having a thickness of 0.5 mm to 1 mm is formed on the elastic body 34.
[0057]
The polisher 32 has, for example, a shape pattern composed of a plurality of convex portions, and a transfer plate corresponding to the convex pattern is sandwiched between the transfer mold and the tool, and the pitch is adjusted to the tool base 35 to which the pitch is attached. Is heated to its softening temperature, and the pitch is transferred to the tool base 35 side to be molded. At this time, an elastic body 34 such as rubber is baked in advance on the tool base 35 side.
[0058]
The polishing tool 31 of the present reference example configured as described above can be easily obtained by interposing a ring-shaped elastic body 34 having low hardness in the pressing direction of the tool (perpendicular to the polishing surface). In the lateral direction (the horizontal direction with respect to the polishing surface, that is, the polishing movement direction), the deformation of the ring-shaped elastic body 34 is restricted by the protrusion 36 at the center of the tool base 35. Therefore, it is difficult to deform and the amount of lateral deformation is small.
[0059]
Therefore, when polishing a workpiece whose shape of the workpiece surface is aspheric and partially changes in curvature at the location to be polished, the polishing surface of the polisher 32 is made of an elastic body 34 having a low hardness. Since it plays a sufficient role and deforms along the aspherical shape of the work surface even with a light load, the entire polishing surface of the polisher 32 uniformly hits the work surface, and the work surface can be uniformly polished. Thereby, even if it grind | polishes the surface where the curvature of a to-be-processed surface changes with places, the shape precision after grinding | polishing can be finished with high precision. In addition, by polishing, a relative speed is generated between the work surface and the (pitch) polisher polishing surface, and due to the shearing force generated therewith, a lateral force is exerted on the polisher 32 and the elastic body 34. Works. However, a concentric projecting portion 36 is provided at the center of the tool base 35, and this projecting portion 36 serves as a core of the ring-shaped elastic body 34, so that the elastic body 34 is laterally moved (direction of polishing movement). The deformation of is suppressed little. That is, the lateral deformation of the (pitch) polisher 32 affixed to the elastic body 34 is similarly suppressed by the protrusion 36. Thereby, the crack and destruction of the pitch which comprise a polisher can be prevented. In addition, when pressing the pitch against the surface to be processed, an elastic body such as rubber or resin having low hardness is used, so the rigidity in the pressing direction of the tool is low, and the curvature is locally as described above. Even when a changing workpiece is polished, the workpiece is smoothly deformed along the aspherical shape of the surface to be polished.
[0060]
Next, a modification of this reference example is shown in FIG. In this modification, as a member for restricting deformation of the elastic body, a concentric annular protrusion 37 is provided integrally with the tool base 35x along the outer peripheral portion instead of the center portion of the tool base 35x. The annular base 37 is baked on the tool base 34x so as to fit an elastic body 34x such as a disc-like rubber, and a (pitch) polisher 32x having a thickness of 0.5 to 1 mm is formed thereon. Yes. With the configuration in which the annular projecting portion 37 of the tool base 35x surrounds the elastic body 34x, the deformation of the elastic body 34x due to the lateral shearing force generated by polishing is regulated.
[0061]
Also in this modified example, the first shown in FIG. 4 The same effects as those of the reference example can be obtained.
[0062]
Thus, the second 4 According to the polishing tool of the reference example, a concentric protrusion is provided at the center of the tool base, and the protrusion is used as a core of a rubber or resin elastic body having a low ring-shaped hardness, or By providing a concentric annular protrusion around the periphery of the tool base and surrounding the disk-like elastic body having a low hardness with this annular protrusion, deformation in the elastic body lateral direction (polishing motion direction) is reduced. can do. That is, since the structure is flexible in the axial direction (direction in which the tool is pressed against the surface to be polished) and strong in the lateral direction (direction of polishing movement), the polisher is destroyed by the shearing force generated during polishing. Even when polishing an aspherical surface or the like that has no fear and changes in curvature, the polisher can be uniformly brought into contact with the surface to be processed.
[0063]
Next 5 The polishing tool of the reference example will be described with reference to FIGS. 18 (a) and 18 (b).
[0064]
18 (a) and 18 (b), the polishing tool 41 of the present reference example can be easily adapted to the shape of a work surface having an arbitrary curvature with a small polishing load. It is composed of a polisher 42 made of pitch material, an elastic body 44, and a tool base (tool shank) 45. The tool base 45 is preferably a cylindrical shape having a sufficiently small diameter with respect to the work surface of the work piece. The tool diameter is 20 mm. A disc-like elastic body 44 made of polychloroprene rubber having a thickness of 2 mm and a JIS hardness of about 30 is attached to the surface of the tool base 45 facing the workpiece. A pitch polisher 42 of 5 mm to 1 mm is formed. The pitch polisher 42 is formed along the outer peripheral portion of the elastic body 44 into a ring shape having a width of about 1/5 to 1/20 of the tool diameter and a thickness of 0.5 to 1 mm. Specifically, as shown in FIG. 18B, a plurality of strip-shaped convex pieces 42 a having a width of 1 to 2 mm and a thickness of about 1 mm are arranged at intervals on the outer peripheral portion of the elastic body 44. A polisher having a shaped pattern is used. In forming the pitch, for example, a transfer plate corresponding to such a convex pattern is sandwiched between the transfer mold and the tool, and the pitch is adjusted to the tool base 45 to which the pitch is attached, and the pitch is heated to its softening temperature to be the tool base 45. Molded by transferring the pitch to the side. At this time, an elastic body 44 such as rubber is baked in advance on the tool base 45 side.
[0065]
The polishing tool 41 of the present reference example is configured as described above, and only the plurality of convex portion pieces 42a act as a polisher at the time of polishing, and easily even if the pressing force of the tool is small. Even when polishing a workpiece that is deformable and whose workpiece surface has an aspherical shape and the curvature of the workpiece is partially changed at the location to be polished, the workpiece hits the workpiece surface in a form that is substantially close to line contact. Therefore, compared to a tool that makes contact with the surface, the partial change of the polished surface of the pitch polisher can be much smaller, and it is not necessary to lower the hardness of the elastic body of the polishing tool. The surface is deformed along the shape of the surface, the polished surface of the polisher hits the surface to be processed uniformly, and the entire surface can be polished uniformly. As a result, even if the surface of the surface to be processed has a different curvature depending on the location, the shape accuracy after polishing can be finished with high accuracy.
[0066]
Thus, according to the polishing tool of the present reference example, the polishing surface can be pressed against the processing surface with a low polishing load even when the elastic body has high hardness as described above. The pitch polisher is not damaged and is advantageous for smoothing the swell.
[0067]
A modification of this reference example is shown in FIG. In this modification, instead of using the pitch, (foamed) polyurethane having a thickness of about 0.5 to 1 mm is formed in a ring shape, and this ring-shaped polisher 42x is attached to the tool base. Also, instead of (foamed) polyurethane, tetrafluoroethylene resin (Teflon) or the like can be used, and any other material may be used as long as it can be used as a polisher. Absent.
[0068]
In this way, when (polyurethane) polyurethane, tetrafluoroethylene resin (Teflon), etc. are used as a polisher, there is no disadvantage that it is brittle like a pitch and easily cracks, and it has some elasticity per se. Therefore, an elastic body as a backup is not particularly required, and it can be used by directly sticking to the tool base surface.
[0069]
According to the polishing tool of this reference example, even when polishing an aspherical surface or the like whose curvature changes, the polisher polishing surface comes into contact with the processing surface uniformly in a line contact manner with a small polishing load. Therefore, since the amount of deformation of the polisher can be reduced, there is no problem that the pitch polisher is destroyed during polishing. Further, it is not necessary to reduce the hardness of the elastic body as a backup for the pitch polisher. As described above, since a tool having high hardness can be used as a polisher and polishing can be performed with a light load, the efficiency of smoothing the undulation can be increased.
[0070]
【The invention's effect】
As described above, according to the present invention, when polishing a processed surface such as an aspherical surface having a large curvature change, the polisher polished surface is a processed surface even if the polished surface has a large change in curvature. Smoothly follow the shape. Therefore, the entire polished surface of the polisher uniformly hits the surface to be processed, and the entire surface to be processed can be uniformly polished without causing a change in shape. Furthermore, the polished surface of the polisher can smoothly smooth the waviness without following the irregular shape of ripples in a short period, and aspherical shapes of optical elements such as lenses and mirrors can be polished with high accuracy. can do.
[0071]
The polisher is composed of a plurality of independent polisher pieces and the elastic body is also composed of a plurality of independent elastic parts, which can be easily deformed in the vertical direction but deformed in the lateral direction. Hateful Lattice Mount on plate Between the adjacent elastic parts, a fall prevention wall is provided for preventing the fall in a direction perpendicular to the load direction. As a result, the amount of deformation of the polished surface of the polisher can be increased. As a result, it can quickly and smoothly follow large changes in the shape of the work surface, and the polished surface of the polisher deforms following the shape of the work surface. Make it work on the work surface efficiently without releasing the polishing pressure. Uniform polishing is possible The further Without causing shape deterioration due to polishing, small Periodic waviness can also be smoothed efficiently.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of a polishing tool of a first reference example.
FIG. 2 is a plan view of a plate-like member used for the polishing tool of the first reference example.
FIG. 3 is a sectional view showing a modification of the polishing tool of the first reference example.
FIGS. 4A and 4B are diagrams showing an aspect of polishing an aspheric surface of a workpiece by the polishing tool of the first reference example, and FIG. 4C is a ripple of the workpiece by the polishing tool. It is a figure which shows the aspect which grinds and removes.
FIG. 5 is a diagram showing a polishing scanning locus with respect to a processing surface of the polishing tool of the first reference example.
[Fig. 6] (a) Second of reference It is sectional drawing of the polishing tool of an example, (b) is an end view of the polisher in the polishing tool.
FIG. 7 (a) and (b) Second of reference It is a top view of the plate-shaped member which can be used for the polishing tool of an example.
[Figure 8] (a) Second of reference It is sectional drawing which shows the modification of the example polishing tool, (b) is an end view of the polisher in the modification of the polishing tool.
FIG. 9 (a) and (b) Second of reference It is a figure which shows the aspect which grind | polishes the aspherical surface of the workpiece by the polishing tool of an example, (c) is a figure which shows the aspect which grinds and removes the ripple of the workpiece by the polishing tool.
FIG. 10 (a) Third of reference It is sectional drawing of the polishing tool of an example, (b) is a bottom view of the polishing tool.
FIG. 11 Third of reference It is a figure which shows the aspect which grind | polishes the aspherical surface of the workpiece by the grinding tool of an example.
FIG. 12 shows the first of the present invention. 1 Examples of polishing tools The It is sectional drawing shown.
FIG. 13 shows the first of the present invention. 1 Examples of polishing tools one It is sectional drawing which shows a modification.
FIG. 14 shows the first of the present invention. 1 It is sectional drawing which shows the other modification of the polishing tool of the Example.
FIG. 15 shows the first of the present invention. 1 It is sectional drawing which shows the other modification of the polishing tool of the Example.
FIG. 16 4 It is sectional drawing of the polishing tool of the reference example.
FIG. 17 4 It is sectional drawing which shows the modification of the polishing tool of the reference example.
FIG. 18 (a) is the first 5 It is sectional drawing of the grinding | polishing tool of the reference example, (b) is a top view of the polisher in the grinding tool.
FIG. 19 shows the first of the present invention. 5 It is a top view of the other polisher in the polishing tool of the reference example.
FIG. 20 is a cross-sectional view illustrating an example of a conventional polishing tool.
[Explanation of symbols]
1 Polishing tool
2 Polishers
3 Plate-shaped member (leaf spring)
3a Central segment
3b Peripheral segment
3x polyurethane foam sheet
4 Elastic body
5 Tool base
11 Polishing tool
12,12x Polisher
12a, 12xa Polisher piece
13, 13x Plate member (leaf spring)
13a segment
13b Through hole
13c slit
14 Elastic body
15 Tool base
21 Abrasive tools
22 Polisher
22a Polisher piece
23,23x Plate member (leaf spring)
23a, 23xa holding part
23b, 23xb connecting part
24 Elastic body
24a Elastic part
24x coil spring
25,25x Tool base
26 Fall prevention wall
27 Cylinder hole
28 Pressure chamber
29 Movable body
31,31x polishing tool
32, 32x polisher
34, 34x elastic body
35,35x Tool base
36 Projection
37 (annular) protrusion
41 Polishing tool
42 Polisher
42a Convex part
42x ring polisher
44 Elastic body
45 Tool base

Claims (1)

In a polishing tool comprising a polisher, an elastic body that holds the polisher, and a cylindrical tool base to which the elastic body that holds the polisher is attached,
Between the polisher and the elastic body is interposed a lattice-like plate-like member having rigidity that is deformable in a direction perpendicular to the surface but difficult to deform in the same direction as the surface,
The polisher is composed of a plurality of independent polisher pieces and the elastic body is composed of a plurality of independent elastic pieces;
Each of the polisher pieces and each of the elastic pieces are respectively attached to opposing portions with the lattice-like plate-like member interposed therebetween, and the adjacent elastic pieces are perpendicular to the load direction. A polishing tool, characterized in that a fall prevention wall for preventing fall is provided in a direction.

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