JP2004237437A - Lap tool and method of manufacturing lap tool and method of polishing optical part - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a lap tool, which has flexibility following the shape of a surface to be polished and precisely and efficiently flattens the surface to be polished even though irregularities caused by a pre-processing remain, when polishing optical parts such as large-diameter aspheric glass lenses. <P>SOLUTION: The lap tool 1 is provided with a dome-like elastic body 2, a lap layer 3 having polishing property over an adhesive 3b formed on one surface of the elastic body 2 and a lap material 3a and a crack 8 extending from the surface of the lap layer 3 to one surface of the elastic body 2 for allowing the lap layer 3 to have flexibility. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

  The present invention relates to a lap tool used for smoothing or mirroring an optical component such as an optical lens, a method for manufacturing the lap tool, and a method for polishing an optical component.

  In the industrial field, optical components such as camera lenses, telescope lenses, microscope lenses, condenser lenses for steppers, eyeglass lenses, as well as prisms, cover glasses, optical filters, etc. And the like. Among these, a camera lens is used in combination with several types of spherical glass lenses and aspherical glass lenses. However, aspherical glass lenses are difficult to process and those with high precision are very expensive. The background art will be described with the aspherical glass lens as a representative example.

  Conventionally, a method of polishing an aspherical glass lens is to form a slurry in which abrasive grains are dispersed in a processing liquid by using several types of spherical sanding dishes on the surface of the aspherical glass lens roughly cut into a predetermined shape. While supplying, the whole shape is adjusted by partially sanding, and mirror finishing is performed while partially polishing using a spherical polishing dish in the same manner.

  In recent years, a method of performing mirror finishing with a polisher having a configuration in which a polishing member is attached to a polishing plate made of an elastic body as shown in Patent Document 1 (hereinafter referred to as an elastic polisher) has also been partially implemented. ing.

JP-A-8-206952

  However, when an elastic polisher as shown in Patent Document 1 is used, there are the following problems.

  In other words, when the aspherical glass lens is ground with high precision to improve the roughness of the ground surface, and polished with an elastic polisher without sanding, if the ground surface has undulation, it will be polished in the same shape and continued I cannot get a mirror surface.

  The present invention has been made in view of the above circumstances, and when polishing an optical component typified by an aspherical glass lens or the like, efficiently removes the undulation of the ground surface of the optical component, and also finishes the mirror surface. It is an object of the present invention to provide a lapping tool, a method of manufacturing the lapping tool, and a method of polishing an optical component.

  The lapping tool of the present invention provides a dome-shaped elastic body, a lapping layer having an abrasive property including an adhesive formed on one surface of the elastic body and a wrapping material, and imparting flexibility to the lapping layer. And a crack extending from the surface of the wrap layer to one surface of the elastic body.

  According to this configuration, a crack is formed in the wrap layer having less elasticity than the elastic body, and the wrap layer is divided into fine portions that hold the wrap material, so that the wrap layer flexibly follows the bending of the elastic body. Becomes possible.

  In this case, the adhesive is an adhesive made of a thermosetting resin material, and the wrapping material is preferably a wrapping material pulverized to an average particle size of 1 mm or less. The wrapping material referred to here is a generally known, porous fine particle having a large number of pores that can be obtained by crushing a crystal of a mineral substance and holding an abrasive, such as cast iron and diamond. , Alumina and the like, but are not limited thereto. In addition, those in which the porous fine particles are contained in a resin such as foamed polyurethane are also included in the wrapping material. These wrapping materials are pulverized to an average particle size of 1 mm or less, so that the surface of the wrapping layer is easily smoothed. Therefore, sufficient polishing can be obtained without damaging the surface of the workpiece during polishing.

  According to this configuration, by using the adhesive made of the thermosetting resin material, even if a crack is formed in the adhesive, the adhesive with the elastic body can be maintained while holding the wrapping material. In addition, the grinding ability of the lapping tool can be improved by using a lapping material having an average particle diameter of 1 mm or less having grindability.

  The method of manufacturing a lapping tool according to the present invention includes a step of fixing the dome-shaped elastic body to the fixing member, and roughening one surface of the elastic body to increase the adhesion between the surface of the elastic body and the adhesive. A step of applying an adhesive to one surface, a step of bonding a wrapping material to the entire surface of the adhesive, a step of drying the adhesive, and an adhesive for imparting flexibility to the adhesive. Forming a crack extending from the surface of the elastic member to one surface of the elastic body.

  According to the method of manufacturing a lapping tool, the surface of the elastic body is roughened to improve the adhesiveness with the adhesive, and the adhesive holding the wrapping material is cracked, and the flexibility of the elastic body is improved. , A lapping tool configured so that the lapping material and the adhesive flex flexibly can be efficiently manufactured.

  In this case, the step of applying the adhesive preferably includes a step of applying an adhesive made of a thermosetting resin material, and the step of adhering the wrapping material includes a lapping material pulverized to an average particle size of 1 mm or less. Is preferable.

  Further, the step of forming a crack preferably includes a molding rubbing step of pressing a molding tool having a curved surface shape to the lap layer while supplying a polishing liquid to the rotating lap layer, and the molding rubbing step is further included. And a rubbing step using a forming tool having a radius of curvature substantially equal to or smaller than the radius of curvature of the wrap layer.

  According to these configurations, the adhesive can be easily cracked in the adhesive of the wrap layer by pressing the forming tool against the wrap layer and rubbing the elastic body and the wrap layer while forming them. At the same time, in the bonded state, the wrapping materials of the wrapping layers whose heights from the elastic body surface are different from each other can be shaped to approximately the same height so as to follow the shape of the elastic body. This makes it possible to smooth the surface of the lap layer, so that when polishing the workpiece, the surface can be polished without being damaged by the lap layer. Furthermore, by making the radius of curvature of the forming tool substantially equal to or smaller than the radius of curvature of the wrap layer, the wrap layer can be bent in a wavy manner, and cracks can be effectively formed.

  The polishing method for an optical component of the present invention is to polish a surface to be polished of an optical component to a lap layer while supplying a processing liquid containing abrasive grains to a lap layer of a rotating lap tool. Polishing step.

  According to this configuration, the lapping layer is polished to the surface to be polished of the optical component in such a manner that the lapping layer is in close contact with the lapping layer. it can.

  Hereinafter, the lap tool of the present invention will be described with reference to the drawings, but the present invention is not limited to the following embodiments.

  FIG. 1A is a sectional view showing an embodiment of the lapping tool of the present invention. The lapping tool 1 includes a dome-shaped elastic body 2, a wrap layer 3 formed on a convex surface which is one surface of the elastic body 2, a fixing member 10 for fixing the elastic body 2, and the other of the elastic body 2. And a pressurized fluid 6 filled in the hollow structure 7 formed by the surface and the fixing member 10. The fixing member 10 includes a rotating shaft 11 that transmits a rotating force to the lap tool 1, a disk-shaped plate 12 integrated with the rotating shaft 11, an elastic stopper 13 that fixes the elastic body 2 to the plate 12, and a hollow member. It comprises a pressure fluid inflow path 4 for allowing the pressure fluid 6 to flow into the structure 7, and a one-way throttle valve 5 provided in the pressure fluid inflow path 4.

  In the lapping tool 1 having this configuration, the plate 12, the elastic stopper 13, the elastic body 2, and the lapping layer 3 are integrally formed by obtaining rotational force from a device to which the lapping tool 1 is attached via a rotating shaft 11. Rotate. A pressure fluid 6 is sealed in the hollow structure portion 7, and the internal pressure of the pressure fluid 6 can be adjusted to freely change the elastic force of the elastic body 2 on which the wrap layer 3 is formed. The pressure of the pressure fluid 6 is adjusted by the one-way throttle valve 5. The one-way throttle valve 5 can seal the pressurized fluid at a constant pressure from the pressurized fluid inflow path 4 into the hollow structure portion 7, and can adjust and maintain the internal pressure of the pressurized fluid 6 at a constant pressure.

  As shown in FIG. 1 (b), the wrap layer 3, which is a main part of the present invention, is formed by forming a layer of an adhesive 3b on the surface of an elastic body 2 and bonding the wrap material 3a to the adhesive 3b. is there. The wrap layer 3 has fine cracks 8 extending from the surface of the adhesive 3b, which is the surface of the wrap layer 3, to the elastic body 2, and the wrap layer 3 flexes freely according to the flexibility of the elastic body 2. It has a configuration that allows for flexibility. That is, each part of the adhesive 3 b divided by the crack 8 can individually follow the bending of the elastic body 2 while holding the wrapping material 3 a. Accordingly, by providing the lap layer 3 with fine cracks 8 extending to the elastic body 2, the lap layer 3 has improved followability to flexibly follow the curved surface shape of the workpiece polished by the lap layer 3. .

  The wrap layer 3 may include a brightener, a lubricant, and the like in addition to the adhesive 3b and the wrap material 3a. In addition to such a configuration of the wrap layer 3, an adhesive having flexibility corresponding to the adhesive 3b provided with flexibility by the formation of the cracks 8 may be used. A configuration in which an elastic pad having an adhesive layer to which is adhered is attached to the elastic body 2.

The elastic body 2 has a dome shape obtained by cutting out a part of a sphere having a predetermined radius of curvature. The elastic material has a thickness of 0.1 to 10 mm and a JIS A hardness (type A durometer) of 10 mm. A nitrile rubber having physical properties in a range of from 100 to 100, a Young's modulus of 10 ² to 10 ³ N · cm ⁻² , and a heat resistance temperature of 100 ° C. is desirable. Other than these, natural rubber, styrene rubber, butadiene rubber, silicon rubber, fluorine rubber, and other materials may be used as long as they exhibit the above physical properties. In the examples, nitrile rubber having a JIS A hardness (type A durometer) of 90 was used. FIG. 1 illustrates the elastic body 2 having a shape obtained by cutting out a part of a sphere having a predetermined radius of curvature. However, a hollow structure 7 is also formed of an elastic material according to the shape and material of the work. Elastic bodies can also be selected.

  As the adhesive 3b used for the wrap layer 3, a bond E set manufactured by Konishi Co., Ltd., which is a two-component curable thermosetting resin adhesive, is used. As the wrap material 3a, the average particle diameter of FC20 gray cast iron is 1 mm or less. Among these, those more preferably pulverized to 0.01 mm were used. Further, examples of the pressure fluid supplied or sealed to the hollow structure portion include air, water, and the like.

  Next, a method of manufacturing the lapping tool 1 in the case where cast iron powder is used for the lapping material 3a of the lapping layer 3 will be described. First, a lap tool in which the dome-shaped elastic body 2 is fixed to the fixing member 10 shown in FIG. Hereinafter, as shown in the flow chart of forming the wrap layer in FIG. 3, the surface treatment of the elastic body 2, cleaning, drying, application of the adhesive 3b, bonding and drying of the wrap material 3a, shaping of the surface of the wrap layer 3, and cleaning. , And the lapping tool 1 is completed. Hereinafter, each step will be described with reference to the drawings.

(Elastic surface treatment / washing / drying)
As shown in FIG. 4A, the surface treatment of the elastic body 2 is performed by sandblasting, in which fine sand is blown onto the convex surface 2a of the elastic body 2, to make the surface 2a of the elastic body 2 rough. . By making the surface 2a of the elastic body 2 rough, the adhesive strength with the adhesive 3b applied in a later step can be increased. The processing conditions for sandblasting are as follows: the particle size of the sand is 80 μm, and the pressure of the air for blowing the sand is 0.5 MPa. After the sandblasting, cleaning is performed, and the cleaning is performed by cleaning the sandblasted surface with compressed air having a pressure of 0.5 Mpa. Next, water is poured and washed with a brush or the like to remove all foreign matters and dirt. After washing with water, it is dried with hot air at 60 ° C. The method of making the surface rough is not limited to sand blasting, and the same effect can be obtained by a method such as rubbing with sand paper or polishing with a rough whetstone.

(Adhesive application)
As shown in FIG. 4B, the adhesive 3a is applied uniformly and thinly to the surface 2a of the elastic body 2 to apply the adhesive 3a to the dried surface 2a of the elastic body 2. Since the adhesive 3b has viscosity and is difficult to apply as it is, it is desirable to apply the adhesive 3b while heating to reduce the viscosity and maintaining a constant temperature.

(Wrapping and drying)
Next, the wrapping material 3a is bonded onto the adhesive 3b. A cast iron powder, which is a wrapping material 3a, is sprinkled on the surface of the adhesive 3b so as to cover the entire surface of the adhesive 3b, and the wrapping material 3a that is not adhered is blown off. Thus, as shown in FIG. 4C, the wrapping material 3a is uniformly adhered to the surface of the adhesive 3b. When the adhesive 3b is dried, the adhesive 3b hardens, and the wrapping material 3a is integrated with the elastic body 2 via the adhesive 3b.

(Shaping and cleaning of the wrap layer surface)
Then, in order to form a crack in the adhesive 3b, the surface of the wrap layer 3 is molded and rubbed. FIG. 5D is a diagram showing a molding rubbing step, in which the fixing member 10 moves in the forward rotation 36 and the reverse rotation 37, the wrap layer 3 attached to the fixing member 10, and the wrap layer 3 is pressed. A forming tool 30 made of cast iron applied thereto; a hairpin 32 for moving the forming tool 30 along an elliptical trajectory 35 while adjusting a pressure 34 on the forming tool 30 via a pivot 31 of the forming tool 30; 3 and the polishing liquid 33 supplied to the forming tool 30, the forming is rubbed.

  In this state, the fixing member 10 is mounted on a polishing machine having a spherical polishing mechanism, and rotates in both forward and reverse directions. At this time, as already described with reference to FIG. 1A, the hollow structure 7 of the fixing member 10 is filled with the compressed air via the pressure fluid inflow path 4 and the one-way throttle valve 5. By operating the one-way throttle valve 5 to adjust the pressure of the compressed air and seal the compressed air, the elastic body 2 can maintain a predetermined elastic force. Next, the forming tool 30 is pressed against the wrap layer 3 to rub the convex wrap layer 3 against the concave surface of the forming tool 30. The forming tool 30 is pressed against the wrap layer 3 by the hairpin 32, and the pressing 34 on the wrap layer 3 is adjusted by the vertical movement of the hairpin 32. Furthermore, the hairpin 32 moves the forming tool 30 so as to draw an elliptical trajectory with respect to the rotation axis of the fixed member 10. By these actions, the forming tool 30 evenly rubs the entire surface of the wrap layer 3. After the processing, the processing liquid 33 and residual powder generated by rubbing during molding are removed by washing.

  Due to the molding rubbing, a fine crack 8 as shown in the cross-sectional view of FIG. 5E is generated in the layer of the adhesive 3b of the wrap layer 3 that rubs with the molding tool, and the layer of the cured adhesive 3b is divided. You. The layer of the adhesive 3b is divided into a large number of minute portions each holding the wrapping material 3a even in a plane. Each of the divided layers of the adhesive 3b is adhered and fixed at a portion in contact with the elastic body 2, and can flexibly follow the elastic body 2 without separating from the elastic body 2 in response to the deformation of the elastic body 2. . That is, the lap tool 1 has the lap layer 3 having elasticity.

  In the forming rubbing step, the surface of the wrapping material 3a of the wrapping layer 3 is polished by the forming tool 30 and the polishing liquid 33 to become a fine smooth surface of fine cast iron powder. Therefore, the lapping layer 3 is not only polished and mirror-polished the workpiece, but also has a grindability made of cast iron, so that swelling and the like can be removed and mirror-polished.

  The curved surface that rubs with the lap layer 3 of the forming tool 30 has a radius of curvature substantially equal to or smaller than the radius of curvature of the curved surface of the wrap layer 3. Can be formed, which is preferable. As the polishing liquid 33 for rubbing the molding tool 30 and the lap layer 3, a slurry of emery, alumina oxide, cerium oxide or the like in water was used.

  By using this lapping tool 1, when polishing an optical component such as a large-diameter aspherical glass lens as a workpiece, even if the polished surface of the optical component has irregularities due to pre-processing, it is highly accurate and efficient. The surface to be polished can be smoothed to obtain a desired smooth surface or mirror surface.

  Further, as an example using the lapping tool 1 of the present invention, a case will be described in which, in an optical glass lens, the concave side of the optical glass lens is ground into a desired curved shape and then polished to a smooth surface using the lapping tool 1. I do.

  As shown in FIG. 2, the configuration for performing the polishing process is illustrated with a lap tool 1 including a fixing member 10 and an elastic body 2 having a lap layer 3 formed on a surface thereof, and mounting the lap tool 1 thereon. A polishing machine, a pressure fluid 6 sealed in a hollow structure 7, a work holder 21 for mounting an optical glass lens (hereinafter referred to as a work 20), and pressing the work 20 onto the lap layer 3 of the lap tool 1. It comprises a mechanism for applying a lap pressure 22 to be applied and a working fluid supply unit 24 for supplying a working fluid 23 containing abrasive grains between the work 20 and the lap layer 3.

  Before polishing the work 20 with the lapping tool 1, the convex side of the work 20 is finished with a spherical grinder and a spherical grinder, and then the convex side is attached to the work holder 21, and subsequently, the shape is shaped by a grinding stone or the like. In the shape creation step of creating, the concave surface of the work 20 is cut into a desired curved surface shape. In this embodiment, the concave surface of the work 20 is formed into a curved surface having a radius of curvature of about 100 mm by grinding.

  Under these configurations, the workpiece 20 is rotated at 50 rpm and the rotating shaft 11 of the lapping tool 1 is rotated at 100 rpm while supplying the machining liquid 23. At this time, a cam follower with an eccentricity of 1.5 mm is attached to the elastic body 2 and the rotating shaft 11 to which the elastic body 2 is attached, so that the rotational torque is not directly transmitted. The lapping layer 3 and the work 20 were relatively swung, and polishing was performed for about 5 minutes. The lap pressure 22 was 3 kgf.

  The concave surface of the work 20 created on the curved surface by the grinding in the shape creation process is almost finished to a predetermined shape, but is slightly ground due to being ground by a grinding wheel having a grinding power. There is. The swell cannot be removed by simply processing the surface to a smooth or mirror surface with the existing elastic polisher as it is, but the mirror surface is finished in the undulation shape. When the lapping tool 1 is used in place of the elastic polisher, the workpiece 20 and the lapping layer 3 of the lapping tool 1 are both rotated in opposite directions, and the lapping layer 3 side eccentrically swings and rubs against each other. Polishing 20 is performed. During this polishing, the undulating shape is removed by the grinding force of the cast iron powder of the wrapping material 3a, and at the same time, it is possible to finish the mirror surface by the abrasive grains in the working liquid 23.

  Here, the radius of curvature of the work 20 is larger than the radius of curvature of the wrap layer 3, and the wrap layer 3 is partially in contact with the concave surface of the work 20, and the portion in contact with the work 20 is polished. Furthermore, since the work 20 and the wrap layer 3 are rotating and swinging with each other, the portions in contact with each other move uniformly over the entire surface of the work 20, and the entire concave surface of the work 20 is processed smoothly. The area of the parts in contact with each other can be optimally set by adjusting the wrap pressure 22 and the pressure of the pressure fluid 6. As described above, the lapping tool 1 of the present invention has a grinding property by cast iron powder in addition to a finishing property such as an elastic polisher, and after finishing a slight undulation, is further finished to a smooth surface and a mirror surface. A tool that can do it.

  The elastic body 2 used here was formed by cutting a part of a sphere having a radius of curvature of 45 mm, and was made of nitrile rubber having a thickness of 1 mm and a JIS A hardness (type A durometer) of 90. The hollow structure 7 formed by the elastic body 2 and the fixed member 10 was filled with compressed air of 0.03 Mpa as the pressure fluid 6 and used while maintaining the internal pressure at a constant pressure by the one-way throttle valve 5. . Further, a working liquid 23 in which abrasive grains were dispersed was supplied between the work 20 and the wrap layer 3 by a working liquid supply unit 24. Optical emery FO3000 # for precision lapping having an average particle size of 3.6 μm was used as polishing abrasive grains.

  As described above, according to the lapping tool 1 of the present invention, the lapping layer 3 serving as a polishing portion of the lapping tool 1 is provided with flexibility, so that the shape of the workpiece can be reliably followed and followed. The polishing accuracy of the free-form surface of the workpiece can be improved. The flexibility of the wrap layer 3 is maintained by the flexibility of the elastic body 2 on which the wrap layer 3 is formed, the fine cracks 8 of the wrap layer 3, and the hollow structure 7 between the elastic body 2 and the fixing member 10. And the pressure fluid 6 being applied. In particular, it is effective to give the wrap layer 3 fine cracks 8. Examples of the workpiece include not only optical glass lenses having a curved surface but also dies for various parts.

  Further, according to the method for manufacturing the lapping tool 1 of the present invention, the lapping layer 3 applied to the elastic body 2 and dried and cured is rubbed with the lapping layer 3 with a molding tool made of cast iron having an approximate shape. By forming fine cracks, the wrap layer 3 having high flexibility can be formed. This is a manufacturing method that can easily and surely form the fine cracks 8 without requiring special tools and processes. The lapping tool 1 having the lapping layer 3 can perform polishing corresponding to any free-form surface of the workpiece.

  Further, according to the method for polishing an optical component of the present invention, the lapping tool 1 is used to polish an optical glass lens or the like, thereby easily and reliably removing the undulation generated during the grinding process. Since mirror finishing is also performed at the same time, optical parts having a free-form surface shape can be stably processed with high quality.

(A) Sectional drawing which shows one Embodiment of the lap tool of this invention. (B) Sectional drawing which shows the structure of a wrap layer. BRIEF DESCRIPTION OF THE DRAWINGS Schematic which shows one Embodiment of the grinding method using the lap tool of this invention. FIG. 4 is a flowchart of forming a wrap layer. (A) (b) (c) Sectional drawing which shows the formation process of a wrap layer. (D) Schematic diagram showing a forming rubbing step. (E) Sectional drawing which shows the formation state of the crack of a wrap layer.

Explanation of reference numerals

1. Wrap tool 2. Elastic body 3. Wrap layer 3a. Wrap material 3b. Adhesive 8. Crack 10 Fixing member 20. Work 23. Processing fluid 30. Molding tools.

Claims (9)

A dome-shaped elastic body,
A lap layer having abrasiveness including an adhesive and a wrap material formed on one surface of the elastic body,
A crack extending from the surface of the wrap layer to the one surface of the elastic body, in order to impart flexibility to the wrap layer,
A wrap tool comprising:   The lap tool according to claim 1, wherein the adhesive is an adhesive made of a thermosetting resin material.   The lapping tool according to claim 1, wherein the lapping material is a lapping material crushed to an average particle size of 1 mm or less. Fixing the dome-shaped elastic body to the fixing member;
A step of roughening one surface of the elastic body to increase the adhesion between the surface of the elastic body and the adhesive,
Applying the adhesive to the one surface,
Bonding a wrap material to the entire surface of the adhesive,
Drying the adhesive,
A step of forming a crack extending from the surface of the adhesive to the one surface of the elastic body, so that the adhesive has flexibility;
A method for manufacturing a lapping tool, comprising: The step of applying the adhesive,
A step of applying an adhesive made of a thermosetting resin material,
The method for manufacturing a lap tool according to claim 4, comprising: The step of bonding the wrap material,
A step of bonding a lap material pulverized to an average particle size of 1 mm or less,
The method for manufacturing a lap tool according to claim 4, comprising: The step of forming the crack includes:
A forming rubbing step of pressing a forming tool having a curved surface shape on the wrap layer while supplying a polishing liquid to the rotating wrap layer,
The method for manufacturing a lap tool according to claim 4, comprising: The molding rubbing step,
A rubbing step using the forming tool having a radius of curvature substantially equal to or smaller than the radius of curvature of the wrap layer;
The method for manufacturing a lap tool according to claim 7, comprising: A polishing method for an optical component using the lap tool according to any one of claims 1 to 3,
A polishing step of polishing the surface to be polished by pressing the surface to be polished of the optical component against the lap layer while supplying a processing liquid containing abrasive grains to the lap layer of the rotating lap tool,
A polishing method for an optical component, comprising:

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