JP2010280007A - Grinding method and grinding device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To carry out processing highly accurately without being influenced by a size of an outer diameter of an optical material. <P>SOLUTION: A tool shaft 13 is arranged tilting to a workpiece shaft 2 holding the optical material 1, and a plurality of cylindrical grindstones 11 are arranged at the same circumference at equal intervals around the rotation axis A of the tool shaft 13 through a plurality of wheel spindles 12. The rotation of the cylindrical grindstones 11 by the rotation of the respective wheel spindles 12 and the revolution of the plurality of the cylindrical grindstones 11 by the rotation of the tool shaft 13 are combined with each other. A recessed shape 1a is formed at the optical material 1 by the outer locus 23 of the grindstones that is the envelope of the outer side line 11a of the respective cylindrical grindstones 11. Even when the outer diameter of the optical material 1 is large, the plurality of cylindrical grindstones 11 with a small diameter are rotated at high speed without causing vibrations or the like so that the optical material is ground with high accuracy. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a grinding method and a grinding apparatus.

  For example, in the processing step of an optical element made of glass, ceramics, or the like, when a desired spherical shape is processed on an optical material, a grinding method using a curve generator (CG) is generally applied as shown in Patent Document 1. Has been.

  In the spherical roughing machine disclosed in Patent Document 1, an optical material is held by a chuck at the tip of a work shaft and rotated while contacting with a cup-type grinding wheel mounted on a tool shaft and rotating at high speed. A spherical surface is created by processing.

  In this case, the spherical surface of the optical material to be processed is formed by rotating the tool axis to provide an angle between the rotation axis of the cylindrical grinding wheel and the workpiece axis, and then processing the cylindrical grinding wheel at the center of the workpiece axis. Control is performed by moving the tool axis in a direction perpendicular to the tool axis direction so that the surfaces come into contact with each other.

The angle for turning the tool axis with respect to the workpiece axis is set by calculating from the target radius of curvature of the spherical surface and the diameter of the grinding wheel.
Also, as in Patent Document 2, a technique using two types of grindstones having different roughnesses has been proposed for the purpose of improving the accuracy of grinding.

  In Patent Document 2, two types of large and small cylindrical grindstones for roughing and finishing are arranged coaxially and doubly with the cylindrical grindstone on the outer peripheral side, and with the cylindrical grindstone on the inner peripheral side By performing the finishing process, the process from roughing to finishing can be performed in one step.

However, in the conventional technique using the cylindrical grindstone as described above, it is necessary to increase the diameter of the cylindrical grindstone in accordance with a lens having a large diameter.
As a result, when the diameter of the cylindrical grindstone is increased, the moment of inertia of the grindstone itself increases, and there is a technical problem such as a slight loss of the balance of the grindstone, an increase in machining vibration, and a decrease in grinding surface accuracy. .

  Also, in grinding processing, the grinding surface tends to become better as the number of revolutions of the grindstone increases. Therefore, machining at high speed is desirable, but in large cylindrical grindstones, vibration due to the increase in the moment of inertia described above is desirable. For this reason, there has been a technical problem that a good ground surface cannot be obtained when the grinding wheel is rotated at a rotational speed higher than a certain level.

JP-A-6-170710 Japanese Patent Publication No. 61-33665

  An object of the present invention is to provide a grinding technique capable of processing with high accuracy without being affected by the size of the outer diameter of a workpiece.

According to a first aspect of the present invention, a first shaft portion that rotatably supports an optical material,
A plurality of second shaft portions that support each of the plurality of grindstones so as to be capable of rotating;
A third shaft portion that supports the plurality of second shaft portions on the same circumference so that end surfaces of the plurality of grindstones facing the optical material are on the same plane, and revolves the plurality of second shaft portions. And an optical material grinding apparatus.
According to a second aspect of the present invention, there is provided an optical material grinding method in which a plurality of grindstones rotating and revolving are pressed against a rotating optical material to grind the optical material.

  ADVANTAGE OF THE INVENTION According to this invention, the grinding technique which can be processed with high precision can be provided, without being influenced by the magnitude | size of the outer diameter of a workpiece.

It is a sectional side view which shows an example of a structure of the grinding device which implements the grinding method which is one embodiment of this invention. It is a top view which shows an example of a structure of the grinding apparatus which implements the grinding method which is one embodiment of this invention. It is an enlarged plan view which shows an example of the effect | action at the time of the process of the concave shaped workpiece of the grinding apparatus which implements the grinding method which is one embodiment of this invention. It is an enlarged plan view which shows an example of the effect | action at the time of the process of the convex shaped workpiece of the grinding apparatus which implements the grinding method which is one embodiment of this invention. It is a front view which shows the example of arrangement | positioning of the grinding stone in the grinding apparatus which implements the grinding method which is one embodiment of this invention. It is a front view which shows the modification of arrangement | positioning of the grinding stone in the grinding apparatus M which is one embodiment of this invention. It is a front view which shows the modification of arrangement | positioning of the grinding stone in the grinding apparatus M which is one embodiment of this invention.

  In the present embodiment, the grinding wheel is fixed by providing a plurality of rotatable grinding wheel shafts on the tool shaft so that the plurality of grinding wheels can be arranged on the same circumference around the rotatable tool shaft.

  And the tool locus of the circular envelope which connected the outermost peripheral side to the tool axis of a plurality of grinding wheels arranged on the same circumference centering on the tool axis, and the circular envelope which can be formed by connecting the innermost peripheral side A workpiece having a concave or convex shape is processed by the tool trajectory.

  That is, in the first aspect of the present embodiment, a tool shaft that is rotatably held, a drive system that rotates the tool shaft, and a cylindrical grindstone that is disposed on the same circumference centered on the tool shaft. And a plurality of grinding wheel shafts that are adjusted so that the end faces of the grinding surfaces of the plurality of cylindrical grinding wheels are on the same plane and are rotatably held, and a drive system that rotates the plurality of grinding wheel shafts. An example of a grinding apparatus is shown.

  At the time of machining, a desired angle is provided on the tool axis with respect to the workpiece axis, and a plurality of rotating cylindrical grindstones arranged on the tool axis are pressed against the workpiece to grind optical materials and the like. Do.

  Further, in the second aspect of the present embodiment, in the grinding apparatus according to the first aspect described above, the tool of the cylindrical grindstone attached to each of a plurality of grindstone shafts arranged on the same circumference around the tool axis. The concave lens is ground by an imaginary circle tool trajectory of an envelope formed by connecting the ridges of the end surface of the outermost grinding surface from the shaft.

  In the third aspect of the present embodiment, in the grinding apparatus of the first aspect described above, the tool axis of the cylindrical grindstone attached to each of a plurality of grindstone axes arranged on the same circumference with the tool axis as the center is the first. The convex lens is ground by the tool trajectory of the virtual circle of the envelope formed by connecting the ridgelines of the inner grinding surface end face.

  According to each aspect of the present embodiment, for example, in the processing of an optical material having a large outer diameter, it is not necessary to increase the diameter of the cylindrical grindstone, and processing with a small diameter cylindrical grindstone is possible. Occurrence of vibration due to the rotation of the cylindrical grinding wheel is suppressed, and a highly accurate processed product can be obtained.

Similarly, since a small-diameter cylindrical grindstone can be used, the rotational speed of the cylindrical grindstone can be made larger than in the case of a large-diameter cylindrical grindstone without worrying about the occurrence of vibration. Can be processed.
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a side sectional view showing an example of the configuration of a grinding apparatus that performs a grinding method according to an embodiment of the present invention.
FIG. 2 is a plan view showing an example of a configuration of a grinding apparatus that performs a grinding method according to an embodiment of the present invention.
FIG. 3A is an enlarged plan view showing an example of an operation at the time of processing a concave workpiece of the grinding apparatus for performing the grinding method according to the embodiment of the present invention.

FIG. 3B is an enlarged plan view showing an example of an operation at the time of processing a convex workpiece of the grinding apparatus for performing the grinding method according to the embodiment of the present invention.
FIG. 4 is a front view showing an example of the arrangement of grinding wheels in a grinding apparatus that performs the grinding method according to one embodiment of the present invention.

  In the present embodiment, in FIG. 1, the left-right direction is described as the X direction, the up-down direction as the Z direction, and the direction perpendicular to the paper surface as the Y direction. As an example, the Z direction is the vertical direction, and the XY plane is the horizontal plane. The directions of the other figures are also as shown.

  As illustrated in FIGS. 1 and 2, in the grinding apparatus M according to the present embodiment, a workpiece shaft column 4 that supports a workpiece shaft 2 (first shaft portion) on a common base 40, and a bottomed surface. A tool shaft column 16 that supports a cylindrical tool shaft 13 (third shaft portion) is disposed facing the X direction.

  The work shaft 2 of the work shaft column 4 is rotated and moved in the direction of the arrow X by a bearing 5 installed on the work shaft column 4, and the optical material 1 is disposed at the opposite end of the work shaft 2 to the tool shaft 13. It is held via a chuck 3 as a work holder.

A driven gear 8 and a bracket 10 are attached to the work shaft 2 inside the work shaft column 4.
The driven gear 8 is fixed to the work shaft 2 and meshes with the drive gear 7a of the shaft 7 connected to the rotary motor 6 provided outside, so that the rotational force of the rotary motor 6 is transmitted to the work shaft 2. It has become.

  As illustrated in FIG. 2, one end of the bracket 10 is fitted to the work shaft 2 so as to be idle, and a drive cylinder 9 is connected to the other end in parallel with the work shaft 2. Is transmitted to the work shaft 2.

  The work shaft 2 can be moved forward or backward in the direction indicated by the arrow X by the thrust of the drive cylinder 9 while being rotated, and the optical material 1 held at the tip is supported by the tool shaft 13 of the tool shaft column 16. It is possible to press against or separate from a plurality of cylindrical grindstones 11 (grindstones) described later.

  The drive cylinder 9 is provided with a displacement sensor (not shown) that monitors the amount of pushing of the work shaft 2 in the X direction.

  On the other hand, in the case of the present embodiment, in the tool axis column 16, a plurality of cylindrical grindstones 11 are provided on the closed end side of the bottomed cylindrical tool axis 13 with respect to the work axis 2, and the rotation axis of the tool axis 13 is It is supported on the same circumference centering on A via the grindstone shaft 12 (second shaft portion) at equal intervals in the circumferential direction.

In this case, as an example, two cylindrical grindstones 11 are arranged at equal intervals of 180 ° in the circumferential direction around the rotation center axis A.
Each cylindrical grindstone 11 has a cup shape, and is provided with a circular grindstone portion 11e that performs a grinding action on the open end.

The circular grindstone portions 11e at the tips of the plurality of cylindrical grindstones 11 are supported by the tool shaft 13 via the grindstone shaft 12 so as to be aligned at the same height in the axial direction (direction of the rotation center axis A). Yes.
A grindstone shaft bearing 30 is arranged in each insertion portion of the grindstone shaft 12 with respect to the tool shaft 13 so that the grindstone shaft 12 is smoothly rotated.

  In each grindstone shaft 12, a driven gear 29 a of a grindstone shaft gear box 29 provided inside the tool shaft 13 is fixed to the other end opposite to the cylindrical grindstone 11.

  The grindstone shaft gear box 29 is connected to a grindstone rotating shaft 34 that is coaxially inserted from the opening end side of the tool shaft 13, and a drive gear 29 b fixed to the tip of the grindstone rotating shaft 34 includes a plurality of grindstone shafts. 12 is engaged with a driven gear 29 a fixed to each of 12.

Thereby, the plurality of cylindrical grindstones 11 are simultaneously rotated (spinned) at the same speed by the rotation of the grindstone rotating shaft 34.
A grindstone driving motor 35 is attached to the other end of the grindstone rotating shaft 34. The grindstone drive motor 35 is mounted on the tool axis column 16 by a pedestal 36.

The grindstone rotating shaft 34 is held coaxially and idly on the tool shaft 13 by a pair of grindstone rotating shaft bearings 33 disposed at both ends.
Further, the tool shaft 13 that holds the grindstone rotating shaft 34 in an idle manner is rotatably held in the tool shaft housing 31 by a pair of tool shaft bearings 32 provided at both ends.

  A tool shaft housing 31 that holds the tool shaft 13 and the grindstone rotating shaft 34 coaxially is fixed to the tool shaft column 16.

  A pulley 37 is attached to the other end of the tool shaft 13 opposite to the cylindrical grindstone 11, and a belt 38 is stretched between the tool shaft drive motor 39 installed on the tool shaft column 16, The rotational force of the shaft drive motor 39 is transmitted to the tool shaft 13.

  That is, in the case of the present embodiment, a plurality of cylindrical grindstones 11 are arranged on the same circumference around the rotation center axis A on the tool shaft 13, and each cylindrical grindstone 11 is rotated by the rotation of the tool shaft 13. It is configured to revolve around the rotation center axis A and to rotate by being rotated by the grindstone rotation shaft 34 via the grindstone shaft 12.

  The tool axis column 16 is installed on a turning base 18 that rotates about a turning center O located at a base 40 between the work axis column 4 and the tool axis column 16.

  When the turning base 18 has a spherical center to be processed into the optical material 1 as the turning center O, the rotation center axis A in the direction of arrow S in FIG. 2 by the servo motor 17 (first position adjusting means) with the turning center O as an axis. And in the first plane (in the XY plane) including the rotation center axis B, it is attached so as to be rotatable.

  A rotary encoder 26 is attached to the servo motor 17, and the relative relative angle θ between the rotation center axis A of the tool shaft 13 and the rotation center axis B of the work shaft 2 is set by turning the turning base 18. It can be carried out.

  Further, on the swivel base 18, the tool axis column 16 is installed so as to be slidable in the direction of the arrow y perpendicular to the tool axis 13, and is screwed into the feed screw 19 and the feed screw 19 to It can be moved by a nut 20 fixed to the side.

As illustrated in FIG. 2, a motor shaft 22 a of a servo motor 22 (second position adjusting means) is coaxially coupled to the feed screw 19 via a coupling 21.
A laser displacement sensor 27 for monitoring the amount of movement of the tool axis column 16 in the arrow y direction is attached to the outer surface of the tool axis column 16.

  The rotary encoder 26 of the swivel base 18, the laser displacement sensor 27 of the tool axis column 16, and the displacement sensor (not shown) for monitoring the pushing amount of the work shaft 2 are connected to a control box (not shown).

  A control box (not shown) is connected to the servo motor 17, the servo motor 22, the drive cylinder 9, and the like for wiring to send and control the control signal.

  The rotary encoder 26 reads the relative angle θ formed by the rotation center axis A of the tool shaft 13 and the rotation center axis B of the work shaft 2, and the laser displacement sensor 27 reads the coordinates in the arrow y direction, and inputs them to the control box. Here, the laser displacement sensor 27 may be a position sensor such as an eddy type displacement sensor.

A control box (not shown) controls the operation of the rotary motor 6 that drives the work shaft 2, the grindstone rotary shaft 34, the grindstone drive motor 35 that drives the grindstone shaft 12, and the tool shaft drive motor 39 that drives the tool shaft 13. .
Hereinafter, an example of the grinding method by the grinding apparatus M of the present embodiment will be described.

  In the grinding apparatus M according to the present embodiment, the optical material 1 is ground by pressing the rotating and revolving cylindrical grindstone 11 against the rotating optical material 1.

  When the optical material 1 to be processed has a concave shape as shown in FIG. 3A, the rotation center axis A is determined from the diameter of the optical material 1 and the target radius of curvature of the concave shape 1a after processing as shown in FIG. In a plurality of cylindrical grindstones 11 that revolve as centers, a grindstone that is a revolution trajectory (envelope of a rotation trajectory of the cylindrical grindstone 11) of the outer line portion 11a that contacts the tool shaft 13 of the circular grindstone portion 11e at the tip. The diameter D1 of the outer locus 23 (tool locus) is determined.

  The diameter D1 of the wheel outer locus 23 is set by selecting the diameter D0 of the plurality of cylindrical grindstones 11, and the relative angle θ between the rotation center axis A of the tool shaft 13 and the rotation center axis B of the work shaft 2 is calculated. .

  Next, the servo motor 17 is driven to turn the turning base 18 by the relative angle θ so that the rotation center axis A of the tool shaft 13 turns about the turning center O shown in FIG.

  Next, as shown in FIG. 3A, the feed screw 19 is driven by the servo motor 22 so that the grinding wheel outer locus 23 of the plurality of cylindrical grinding wheels 11 coincides (intersects) with the rotation center axis B of the workpiece shaft 2. Then, the tool axis column 16 is adjusted by moving it in the direction of the arrow y in FIG.

  At this time, as illustrated in FIG. 3B, when the target processing shape of the optical material 1 is the convex shape 1b, the inner line portion corresponding to the inner side with respect to the tool shaft 13 of each cylindrical grindstone 11 from FIG. The diameter D2 of the grindstone inner trajectory 24 (tool trajectory), which is an envelope connecting the revolution trajectories of 11b, is set by selecting the diameter D0 of the plurality of cylindrical grindstones 11.

  Then, the feed screw 19 is driven by the servo motor 22 in the same manner as in the case of the concave shape 1a in FIG. 3A described above so that the inner locus 24 of the grindstone and the rotation center axis B of the work shaft 2 coincide (intersect). Then, the tool axis column 16 is adjusted by moving it in the direction of the arrow y in FIG.

Next, in order to finish the optical material 1 to a desired medium thickness (thickness dimension at the optical axis (rotation center axis B)), the feed amount of the workpiece axis 2 during processing is set. The feed amount of the work shaft 2 is adjusted by the pushing amount of the drive cylinder 9.
Whether the push-out amount has reached the set value is recognized by a sensor (not shown).

  In the grinding process, the grindstone driving motor 35 is driven to rotate (rotate) each of the plurality of cylindrical grindstones 11 through the grindstone rotating shaft 34 and the grindstone shaft gearbox 29.

  Further, the tool shaft drive motor 39 is driven, the tool shaft 13 is rotated via the belt 38 and the pulley 37, and a plurality of high-speed rotating cylindrical grindstones 11 supported by the tool shaft 13 are replaced with the tool shaft 13. Is rotated (revolved) about the rotation center axis A of the wheel to form a wheel outer locus 23.

  Then, after rotating the optical material 1 supported by the work shaft 2 at a desired number of rotations by the rotary motor 6, the optical material 1 is pushed out toward the cylindrical grindstone 11 by the drive cylinder 9 to rotate and revolve the rotating optical material 1. Grinding is performed in contact with a plurality of cylindrical grindstones 11.

  Here, the rotation speed of each axis is, for example, 15000 rpm for the rotation speed of the grindstone axis 12, 80 rpm for the revolution speed by the tool axis 13, and 21 rpm for the work axis 2 so that the rotation speed of the workpiece axis 2 is 21 rpm. Set up.

  Further, the rotation speeds of the tool shaft 13 and the work shaft 2 are equal to each other when the rotation cycles of the two shafts are matched. Set so that it does not become a multiple relationship.

  When the above-described grinding process is performed and the concave shape 1a (or convex shape 1b) having a desired curvature radius can be formed on the optical material 1 as shown in FIG. 3A and the desired intermediate thickness is approached (for example, the desired intermediate thickness) +50 μm), the rotational speed of the tool shaft 13 or the work shaft 2 is increased, and the grinding residue (in this case, 50 μm) is removed by grinding to improve the accuracy of the processed surface of the concave shape 1a (or convex shape 1b). Finish the finishing process.

  At this time as well, the relationship between the rotational speeds of the tool axis 13 and the work axis 2 is set to a numerical value (for example, 160 rpm and 33 rpm) that does not have an odd-numbered or even-numbered combination or multiple relation as described above.

  A concave shape 1a (or convex shape 1b) having a desired curvature can be formed on the optical material 1, and after reaching a desired medium thickness, the work shaft 2 is retracted by retreating the drive cylinder 9, and each axis is rotated. Stop and remove the optical material 1 from the workpiece axis 2 to finish the machining.

  Thus, according to the grinding apparatus M of the present embodiment, for example, even when the outer diameter of the optical material 1 to be processed is relatively large, a plurality of small-diameter cylindrical grindstones 11 are used and individual cylinders are used. Since the optical material 1 can be ground by rotating the shaped grindstone 11 at a high speed, it is possible to prevent deterioration of surface accuracy due to vibration at high speed generated due to poor balance when using a large diameter grindstone. A processed product such as an optical element in a good state can be obtained.

That is, the concave shape 1a and the convex shape 1b of the optical material 1 can be processed with high accuracy without being affected by the size of the outer diameter of the optical material 1.
In addition, there is an advantage that improvement in surface accuracy can be pursued without worrying about the occurrence of vibrations by high-speed rotation of the plurality of small cylindrical grindstones 11.

5 and 6 are front views showing modifications of the arrangement of the grinding wheels in the grinding apparatus M of the present embodiment.
In the case of FIG. 5, the number of grindstone shafts 12 provided on the tool shaft 13, that is, the number of cylindrical grindstones 11 is increased to three, and the circumferential direction is on the same circumference around the rotation center axis A of the tool shaft 13. In the example shown in FIG.

Accordingly, the configuration of the tool shaft 13 and the grindstone shaft gear box 29 is different from the case of FIG. 4 described above.
Similarly, in the case of FIG. 6, the number of grindstone shafts 12 provided on the tool shaft 13, that is, the number of cylindrical grindstones 11 is increased to four, and on the same circumference around the rotation center axis A of the tool shaft 13. An example is shown in which they are arranged at equal intervals of 90 ° in the circumferential direction.

Accordingly, the configuration of the tool shaft 13 and the grindstone shaft gear box 29 is different from the case of FIG. 4 described above.
Also in the modified examples of FIGS. 5 and 6, the processing method is the same as that in the embodiment of FIG. 4 described above.

  According to the grinding apparatus M of the present modification illustrated in FIGS. 5 and 6, the same effect as that of the above-described embodiment can be obtained, and the number of the cylindrical grindstones 11 can be increased. In the case where the rotational speeds of the respective axes and the like are set to be the same as those in the embodiment, the surface accuracy of the concave shape 1a and the convex shape 1b of the optical material 1 can be further improved.

  On the contrary, when the machining conditions are set with the same surface accuracy as in the above-described embodiment, the machining speed can be expected to be improved, and the time required for machining can be shortened and the throughput can be improved. As a result, the productivity of the grinding process of the optical material 1 is improved.

Further, by increasing the number of cylindrical grindstones 11, the load on each cylindrical grindstone 11 is reduced, and the life can be improved. As a result, the productivity of the grinding process can be improved by reducing the cost.
Needless to say, the present invention is not limited to the configuration exemplified in the above-described embodiment, and various modifications can be made without departing from the spirit of the present invention.

  For example, the revolution radius of the cylindrical grindstone 11 (distance from the rotation center axis A to the grindstone shaft 12) is made variable, and by adjusting the revolution radius, the diameter D0 of the cylindrical grindstone 11 is not changed, and the outside of the grindstone is outside. The diameter D1 of the trajectory 23 and the diameter D2 of the grindstone inner trajectory 24 may be set.

Further, the diameter D2 of the grinding wheel inner locus 24 may be set by a combination of the revolution radius of the cylindrical grinding stone 11 and the diameter D0 of the cylindrical grinding stone 11.
Further, the workpiece is not limited to the optical material 1 and can be applied to processing of arbitrary parts and the like.
The grinding wheel is not limited to a cylindrical shape, and may be a cylindrical shape.

[Appendix 1]
In an optical material grinding apparatus and method for creating a spherical surface by pressing a tool shaft that rotatably supports a tool against a work shaft that rotatably supports a workpiece,
A tool axis supported rotatably,
A cylindrical grindstone that is arranged on a concentric circle around the tool axis,
A grinding wheel shaft that rotatably supports the cylindrical grinding wheel, and that has an end surface that is a grinding surface of the cylindrical grinding wheel on the same plane,
An optical material grinding apparatus and method characterized by comprising:

[Appendix 2]
In the grinding apparatus and method for an optical material according to appendix 1,
Processing an optical material by a locus of a circle formed by connecting the circumferential portions of a plurality of cylindrical grindstones arranged on a circle on the tool axis;
An optical material grinding apparatus and method characterized by the above.

[Appendix 3]
In the optical material grinding apparatus and method according to appendix 1 or appendix 2,
Processing concave optical materials by a circular trajectory that connects the outermost side to the tool axis of the grinding wheel surface,
An optical material grinding apparatus and method characterized by the above.

[Appendix 4]
In the optical material grinding apparatus and method according to appendix 1 or appendix 2,
Processing a convex optical material by a locus of a circle formed by connecting the innermost side to the tool axis of the grinding wheel grinding surface of a plurality of cylindrical grinding wheels arranged on the circle on the tool axis;
An optical material grinding apparatus and method characterized by the above.

DESCRIPTION OF SYMBOLS 1 Optical material 1a Concave shape 1b Convex shape 2 Work shaft 3 Chuck 4 Work shaft column 5 Bearing 6 Rotating motor 7 Shaft 7a Drive gear 8 Driven gear 9 Drive cylinder 10 Bracket 11 Cylindrical grindstone 11a Outer wire portion 11b Inner wire portion 11e Circular grinding wheel portion 12 Grinding wheel shaft 13 Tool shaft 16 Tool shaft column 17 Servo motor 18 Turning base 19 Feed screw 20 Nut 21 Coupling 22 Servo motor 22a Motor shaft 23 Grinding wheel outer track 24 Grinding wheel inner track 26 Rotary encoder 27 Laser displacement sensor 29 Grinding wheel shaft gear box 29a Driven gear 29b Gear 30 Grinding wheel shaft bearing 31 Tool shaft housing 32 Tool shaft bearing 33 Grinding wheel rotation shaft bearing 34 Grinding wheel rotation shaft 35 Grinding wheel drive motor 36 Base 37 Pulley 38 Belt 39 Tool shaft driving motor 40 Base A Tool shaft 13 Rotation center axis B Rotation center axis D0 of the work shaft 2 Diameter D1 of the cylindrical grindstone 11 Diameter D2 of the grinding wheel outer locus 23 Diameter of the grinding wheel inner locus 24 O Turning center θ of the tool shaft 13 Rotation center axis A and rotation center axis B Relative angle M Grinding device

Claims (10)

A first shaft portion that rotatably supports the optical material;
A plurality of second shaft portions that support each of the plurality of grindstones so as to be capable of rotating;
A third shaft portion that supports the plurality of second shaft portions on the same circumference so that end surfaces of the plurality of grindstones facing the optical material are on the same plane, and revolves the plurality of second shaft portions. And an optical material grinding apparatus. In the grinding device of the optical material according to claim 1,
The grindstone is a cylindrical grindstone,
The third shaft portion revolves the plurality of cylindrical grindstones, and is an optical material grinding apparatus. In the grinding device of the optical material according to claim 2,
And a first position adjusting means for turning the third shaft portion in a first plane including the central axis of the third shaft portion and the central axis of the first shaft portion;
An optical material grinding apparatus comprising: second position adjusting means for linearly moving the third shaft portion in a direction orthogonal to the third shaft portion within the first plane. In the grinding device of the optical material according to claim 3,
The third shaft portion is positioned by the first position adjusting means and the second position adjusting means so that the revolution trajectories of the plurality of cylindrical grindstones intersect the central axis of the first shaft portion. Optical material grinding equipment. In the grinding device of the optical material according to claim 4,
The optical material is ground in a concave shape by positioning the third axis so that the revolution trajectory outside the plurality of cylindrical grindstones intersects the central axis of the first shaft part. Material grinding equipment. In the grinding device of the optical material according to claim 4,
An optical system comprising: positioning the third shaft portion so that a revolution trajectory inside the plurality of cylindrical grindstones intersects a central axis of the first shaft portion, and grinding the optical material into a convex shape. Material grinding equipment.   A method of grinding an optical material, comprising pressing a plurality of rotating and revolving grindstones against a rotating optical material to grind the optical material. In the grinding method of the optical material according to claim 7,
The grindstone is a cylindrical grindstone,
A grinding method for an optical material, wherein the optical material is ground using a revolution trajectory of the plurality of cylindrical grindstones as a tool trajectory. In the grinding method of the optical material according to claim 8,
A method of grinding an optical material, wherein the optical material is ground into a concave shape using the revolution trajectory outside the plurality of cylindrical grindstones as a tool trajectory. In the grinding method of the optical material according to claim 8,
A method of grinding an optical material, wherein the optical material is ground into a convex shape using the revolution trajectory inside the plurality of cylindrical grindstones as a tool trajectory.