JP4208364B2 - Spherical surface generating device and spherical surface generating method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a spherical surface generating apparatus and a spherical surface generating method for generating a spherical surface with respect to a workpiece (hereinafter referred to as a workpiece) such as a small-diameter optical element.
[0002]
[Prior art]
7 and 8 show an apparatus disclosed in Japanese Patent Publication No. 7-35009 for creating a spherical surface on a work such as an optical element.
[0003]
As shown in FIG. 7, a control motor 55 that moves the lens holder 52 in parallel with the rotation shaft 52 a is provided on the opposite side of the lens holder 52 from the holding portion of the lens 51. The grindstone 53 to be processed is provided with a control motor 56 that moves the grindstone 53 in a direction perpendicular to the rotation shaft 53a. The grindstone 53 and the control motor 56 are mounted on a substantially fan-shaped base 57. The base 57 is rotatable by a control motor 58 around a rotation center 57a in the vicinity of the contact position between the lens 51 and the tip of the grindstone 53. Further, each of the control motors 55, 56, 58 is connected to a control device 59, and the control device 59 controls the relative angle and the moving direction of the grindstone 53 with respect to the lens 51 as appropriate.
[0004]
When a convex surface is formed on the lens 31 by the apparatus having this structure, as shown in FIG. 8, the lens holder that holds the lens 51 by positioning the tip of the grindstone 53 so as to abut on the rotating shaft 53 a. The convex surface 51 a is created by rotating the grindstone 53 while rotating the 52.
[0005]
[Problems to be solved by the invention]
In the spherical surface generating apparatus described above, the outer diameter of the work piece 51 and the outer diameter of the grindstone 53 need to be reduced as the radius of curvature of the spherical surface created on the work becomes smaller (for example, the outer diameter is 2 mm or less, particularly 1 mm or less). There is. For example, when creating a convex spherical surface having an outer diameter of 1 mm and a curvature radius of 1 mm, a grindstone having an outer diameter of about 0.7 mm is required. When processing is performed with a grindstone having a small grindstone diameter as described above, there is a problem that a desired spherical shape cannot be obtained because the grindstone 53 is bent during the processing.
[0006]
In addition, when processing is performed with a grindstone having a small grindstone diameter, the grindstone is quickly worn out. As a result, there is also a problem that the processing dimension of the workpiece is immediately changed and is not stable.
[0007]
The present invention has been made in consideration of such conventional problems, and a spherical surface generating device and a spherical surface generating device capable of processing a spherical surface with a small curvature radius on a small diameter workpiece with high accuracy with a single grindstone. It aims to provide a method.
[Means for Solving the Problems]
In order to achieve the above object, the spherical surface generating device of the invention of claim 1 is provided with a work holder for holding a work so as to be rotatable, and abutting on a work surface of the work held by the work holder for grinding. In a spherical surface generating device provided with a grindstone that is driven to rotate, a first moving mechanism unit that supports the work holder and moves parallel to the rotation axis, and supports the grindstone, and is perpendicular to the rotation axis. A second moving mechanism unit to be moved, a third moving mechanism unit to move the grindstone in the direction of its rotation axis, and a turn on which the grindstone, the second moving mechanism unit, and the third moving mechanism unit are placed. comprising a drive motor for turning the base about a contact position proximate the workpiece and the grinding wheel, the first, and a control unit for controlling the second and third moving mechanism and the drive motor of the grinding wheel, Wherein the serial to the outer peripheral surface to perform contact with a workpiece surface, and has a disk shape and a cylindrical portion is formed for performing curved surface portion and the finishing of the concave curved surface shape for performing roughing And
[0008]
In the present invention, rough processing close to the curved surface shape is performed on the workpiece by the curved surface shape portion of the disk-shaped grindstone, and finishing processing is performed by the cylindrical portion of the grindstone. Since the disc-shaped grindstone is used, it is not necessary to make the grindstone diameter minute, the bending of the grindstone can be reduced, and a highly accurate spherical surface creation process is possible. Also, since roughing is performed on the curved surface of the grinding wheel and then finishing is performed on the cylindrical portion, the finishing allowance during finishing is uniform, the load during processing is stable, and higher-precision processing is possible. .
[0009]
A second aspect of the present invention is the first aspect of the present invention, wherein the grindstone is a grindstone material in which the curved surface portion and the cylindrical portion are different.
[0010]
In this invention, since the grindstone is composed of a combination of different grindstone materials, it is possible to use a grindstone material suited to the machining conditions, and it is possible to perform highly accurate machining with improved surface accuracy.
[0011]
According to a third aspect of the present invention, there is provided a spherical surface generating method in which a rotating grindstone is brought into contact with the work surface while the work held by the work holder is rotated to create a spherical surface on the work. Forming a concave curved surface shape portion for roughing in the direction of the rotation axis and a cylindrical portion for finishing , and a workpiece rotation axis held by a work holder and a rotation axis of the grindstone The workpiece and the grindstone are respectively rotated in a state of being orthogonal to each other, and the top of the workpiece on the rotation axis and the curved surface shape portion on the outer peripheral surface of the grindstone are brought into contact with each other to process the spherical shape by the curved shape portion on the top of the workpiece. Next, the workpiece and the grindstone are moved relative to each other and positioned so that the cylindrical portion of the grindstone faces the rotation axis of the workpiece, and the top portion of the workpiece on which the spherical shape is processed and the cylindrical portion of the grindstone are brought into contact with each other. This The grinding wheel pivots about a location near, characterized by creating a spherical surface part.
[0012]
In the present invention, as a first step, a curved surface portion of a grindstone having a disk shape is brought into contact with a workpiece, and rough machining is performed to a curved surface size close to a desired curved surface shape. As a second step, the cylindrical portion of the grindstone is brought into contact with the workpiece, and finish processing is performed into a desired curved surface shape. By using a disk-shaped grindstone in this way, it is not necessary to make the grindstone diameter minute, so that the bending of the grindstone can be reduced, and high-precision spherical surface creation processing becomes possible. Also, since roughing is performed on the curved surface of the grinding wheel and then finishing is performed on the cylindrical portion, the finishing allowance during finishing is uniform, the load during processing is stable, and higher-precision processing is possible. .
[0013]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be specifically described with reference to embodiments shown in the drawings. In each embodiment, the same elements are associated with the same reference numerals.
(Embodiment 1)
1 to 3 show a first embodiment of the present invention, FIG. 1 is a plan view of a spherical surface generating device, and FIGS. 2 and 3 are plan views in which a processed portion is enlarged.
[0014]
In this embodiment, the lens is created from a workpiece 1 made of an optical glass material. Before processing, the shape of the workpiece 1 is a columnar shape, and the outer diameter thereof is about 0.1 mm to 3 mm.
[0015]
1 and 2, the workpiece 1 is held in a recess formed in the workpiece holder 2 by adhesion (or suction). The work holder 2 is supported by the tip of the rotary spindle 4 attached to the first moving mechanism 3 that moves in the direction of the rotation axis 2a, and is rotatable. A pulley 5 is attached to the other end of the rotary spindle 4, and is connected to a motor 6 installed on a moving table 3 a constituting the first moving mechanism unit 3 via a pulley 7 and a belt 8. Thus, the rotation of the motor 6 can be transmitted to the rotating spindle 4.
[0016]
The first moving mechanism unit 3 is a mechanism for moving and positioning the rotating spindle 4 in a direction parallel to the rotating shaft 2 a of the work holder 2. The first moving mechanism unit 3 includes a moving table 3a to which a rotating spindle 4 is attached, a guide 3b for guiding the moving table 3a in the direction of the rotating shaft 2a, and a lower part of the moving table 3a. And a drive motor 3d that rotates the feed screw 3c.
[0017]
The grindstone 9 is formed in a disk shape. The grindstone 9 having a disc shape has a curved groove portion 9b and a cylindrical portion 9c as curved surface portions on the outer peripheral portion. The grindstone 9 is attached to the tip of a grindstone spindle 10 having a rotating shaft 9 a that rotates in a direction orthogonal to the rotating shaft 2 a of the work holder 2. The curved groove 9b of the grindstone 9 is formed to have a concave curved surface size close to a desired convex curved surface shape of the lens spherical surface to be created.
[0018]
The grindstone spindle 10 can be rotated at high speed (10,000 rpm to 70,000 rpm) by a driving means (not shown). The grindstone spindle 10 is installed on a moving table 11 a constituting the second moving mechanism unit 11.
[0019]
The second moving mechanism 11 is a mechanism that moves and positions the grindstone spindle 10 in a direction perpendicular to the rotation axis 9 a of the grindstone 9. The second moving mechanism unit 11 is moved by being screwed to the moving table 11a, a moving table 11a to which the grindstone spindle 10 is attached, a guide 11b for guiding the moving table 11a in a direction perpendicular to the rotating shaft 9a. The feed screw 11c feeds the table 11a and a drive motor 11d that rotates the feed screw 11c.
[0020]
The grindstone spindle 10 can be moved and positioned in the direction of the rotating shaft 9a of the grindstone 9 by a third movement mechanism (not shown) provided between the grindstone spindle 10 and the movement table 11a of the second movement mechanism 11. It is configured. In the illustrated embodiment, the third moving mechanism section is hidden by the grindstone spindle 10 and cannot be seen. However, the third moving mechanism is moved forward and backward by the drive motor along a guide extending in pairs in the direction of the rotating shaft 9a. It is a mechanism to be moved, and has the same configuration as the second moving mechanism unit 11.
[0021]
The second moving mechanism unit 11 is fixed on a swivel base 12 having a substantially rectangular plate shape. The swivel base 12 is driven by a drive motor 13 (shown by a dotted circle in the figure) provided at the lower part of the plate shape, so that the rotation center 12a (the center of curvature of the spherical surface of the work 1 and the center of curvature of the work 1) Rotating motion is possible around the matching position).
[0022]
Each of the drive motors 3d, 11d, 13 and the first to third moving mechanism units described above is connected to the control device 14 so that the position and speed of each moving mechanism unit can be set by the control of the control device 14. It has become.
[0023]
In the spherical surface generating device having such a configuration, first, the cylindrical workpiece 1 is held by the workpiece holder 2, the driving motor 3 d of the first moving mechanism unit 3 is driven by the control device 14, and the workpiece 1 is moved to the grindstone 9. Move to a predetermined position on the side. At this time, the curved groove 9 b of the grindstone 9 is located at a position facing the workpiece 1.
[0024]
Next, the workpiece 1 and the grindstone 9 are rotated, and as a first step, the drive motor 11d of the second moving mechanism portion 11 is driven to bring the curved groove portion 9b of the grindstone 9 into contact with the workpiece 1 to obtain a desired value. Rough processing is performed to a convex curved surface dimension close to the curved surface shape (see FIG. 2).
[0025]
Thereafter, the drive motor 11d of the second moving mechanism unit 11 is driven to once separate the grindstone 9 from the work 1, and the third moving mechanism unit moves the grindstone 9 in the direction of the rotation axis 9a. 9c is opposed to the workpiece 1.
[0026]
As a second step, the driving motor 11 d of the second moving mechanism unit 11 is driven to bring the grindstone 9 into contact with the top of the convex workpiece 1. In this embodiment, since the distance curved surface R (see FIG. 3) between the processing point of the workpiece 1 and the grindstone 9 and the rotation center 12a of the swivel base 12 is the radius of curvature, this distance R is the desired radius of curvature. The top part of the workpiece is processed while moving the grindstone 9 as described above.
[0027]
Next, when the desired distance R is reached, the position of the workpiece 1 and the grindstone 9 is fixed, and the turning base 12 is rotated to a predetermined angle θ at a predetermined speed by the drive motor 13 (that is, the rotation center 12a is moved). A spherical surface is created by moving (turning) the grindstone 9 by an angle θ with respect to the rotation shaft 2a as the center.
[0028]
According to such an embodiment, since processing is performed using the disk-shaped grindstone 9, it is not necessary to reduce the diameter of the grindstone 9, the bending of the grindstone 9 can be reduced, and a highly accurate spherical surface is created. Processing becomes possible. Further, since roughing is performed with the curved groove portion 9b of the grindstone 9 and then finishing is performed with the cylindrical portion 9c, the finishing allowance during finishing is uniform, and the load during processing is reduced, creating a spherical surface by the grindstone 9 Is stable and more accurate machining is possible.
[0029]
(Embodiment 2)
4 to 6 are enlarged plan views showing the second embodiment in the processing order. The grindstone 9 in this embodiment is formed by a grindstone material in which the curved groove portion 9b and the cylindrical portion 9c are different. For example, the curved groove portion 9b is a roughing grindstone material in which abrasive grains having a grain size of # 400 (about 50 μ) are bonded by metal bond, and the cylindrical portion 9c is softly bonded to finer abrasive grains than the curved groove portion 9b. For example, a finishing grindstone material made of an agent and having, for example, abrasive grains having an abrasive grain size of # 800 (about 20 μm) bonded with a resin bond is used.
[0030]
In this embodiment, the shape of the work holder 2 of the first embodiment is changed, and the outer diameter of the work holder 2 is larger than the outer diameter of the work 1 with respect to the outer diameter of the contact portion between the work holder 2 and the work 1. The shape is made smaller.
[0031]
In the spherical surface generating apparatus of this embodiment, first, the work 1 is held on the work holder 2 with an adhesive, and the drive motor 3d of the first moving mechanism unit 3 is driven by the control device 14 so that the work 1 is moved to the grindstone 9 side. To a predetermined position. At this time, the curved groove portion 9b of the grindstone 9 is located at a position facing the workpiece 1 (that is, the curved surface center of the curved groove portion 9b of the grindstone 9 coincides with the rotation axis of the workpiece 1). )
[0032]
Next, the work 1 and the grindstone 9 are rotated, and as a first step, the drive motor 11d of the second moving mechanism 11 is driven to bring the curved groove 9b of the grindstone 9 into contact with the work 1, 1 is subjected to rough machining with a curved surface size close to a desired curved surface shape (see FIG. 4).
[0033]
Next, the driving motor 11d of the second moving mechanism 11 is driven to once separate the grindstone 9 from the workpiece 1, and the third moving mechanism portion (not shown) moves the grindstone 9 in the direction of the rotation axis 9a. The cylindrical portion 9c is opposed to the workpiece 1 (that is, the cylindrical portion 9c of the grindstone 9 is positioned on the rotation axis of the workpiece 1).
[0034]
Thereafter, as a second step, the drive motor 11d of the second moving mechanism 11 is driven to bring the grindstone 9 into contact with the workpiece 1 and the workpiece 1 is processed. In this embodiment, since the distance R (see FIG. 5) between the processing point of the workpiece 1 and the grindstone 9 and the rotation center 12a of the turning base 12 becomes the curvature radius, this distance R becomes the desired curvature radius. Thus, the grindstone 9 is moved. This movement is performed while the workpiece 1 is being processed by being guided by the guide 11b in a direction perpendicular to the rotation shaft 9a by driving the drive motor 11d.
[0035]
When the desired distance R is reached, the turning base 12 is rotated to a predetermined angle θ at a predetermined speed by the drive motor 13 with the positions of the workpiece 1 and the grindstone 9 fixed (as shown in FIG. 5). The grindstone 9 is moved by an angle θ indicated by a two-dot chain line), and finishing spherical surface creation is performed. In this processing, the surface of the workpiece 1 is previously formed in a convex shape in the first step, and the processing amount in the second step is small, so that a desired spherical surface can be created by one rotation (movement) of the grindstone 9.
[0036]
After the spherical surface generating process, the grindstone 9 is once separated from the surface of the work 1, and then the position where the rotation shaft 2a of the work holder 2 and the rotation shaft 9a of the grindstone 9 are parallel (the grindstone 9 is orthogonal to the rotation shaft 2a in FIG. 6). The drive motor 13 is driven to the position indicated by the solid line) to turn the turning base 12.
[0037]
Next, the drive motor 11d of the second moving mechanism unit 11 is driven to bring the cylindrical portion 9c of the grindstone 9 into contact with the contact-side outer peripheral portion of the workpiece 1, and then the drive motor 11d makes contact with the outer peripheral portion of the workpiece 1. By feeding the grindstone 9 and grinding the outer peripheral portion of the workpiece 1 and driving the drive motor 3d of the first moving mechanism portion 3 to move the workpiece 1 in parallel with the rotating shaft 2a of the workpiece holder 2, the workpiece 1 is moved. Is processed (see FIG. 6).
[0038]
By driving the drive motor 3d in this manner, the outer diameter of the long lens can be formed. If the length of the cylindrical portion 9c of the grindstone 9 is sufficient with respect to the length of the lens outer peripheral surface, it is not necessary to move the workpiece 1 by the drive motor 3d.
[0039]
According to such an embodiment, since the curved groove portion 9b of the grindstone 9 is a roughing grindstone and the cylindrical portion 9c is a finishing grindstone, the surface roughness is improved more efficiently and with higher accuracy. Processing can be performed. Further, in this embodiment, not only spherical surface generation processing but also outer diameter processing can be performed on one apparatus.
[0040]
【The invention's effect】
According to the first aspect of the present invention, since the disc-shaped grindstone is used, it is not necessary to make the grindstone diameter minute, the wobbling of the grindstone can be reduced, and high-precision spherical surface creation processing is possible. Since rough machining is performed on the curved surface shape portion and finishing processing is performed on the cylindrical portion, the finishing allowance during finishing is uniform, the load during machining is stable, and higher-precision machining is possible.
[0041]
According to invention of Claim 2, the grindstone material matched with the process conditions can be used, and the highly accurate process which the surface precision improved can be performed.
[0042]
According to the invention of claim 3, it is possible to reduce the bending of the grindstone, to enable high-precision spherical surface creation processing, to make the finishing allowance uniform during finishing processing, and to stabilize the load during processing. High-precision processing is possible.
[Brief description of the drawings]
FIG. 1 is a plan view showing the entirety of a first embodiment of the present invention.
FIG. 2 is a plan view showing a first step of the first embodiment.
FIG. 3 is a plan view showing a second step of the first embodiment.
4 is a plan view showing a first step of the second embodiment. FIG.
FIG. 5 is a plan view showing a second step of the second embodiment.
FIG. 6 is a plan view showing a final step in the second embodiment.
FIG. 7 is a plan view of a conventional spherical surface generating device.
FIG. 8 is an enlarged plan view of a processed portion by a conventional spherical surface generating device.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Work 2 Work holder 3 1st moving mechanism part 9 Grinding wheel 11 2nd moving mechanism part

Claims (3)

In a spherical surface generating device provided with a grindstone that is rotatably provided so as to rotate a work holder in contact with the work surface of the work held by the work holder, and a work holder that holds the work.
A first moving mechanism for supporting the work holder and moving the work holder in parallel with the rotation axis;
A second moving mechanism for supporting the grindstone and moving it at a right angle to its rotational axis;
A third moving mechanism for moving the grindstone in the direction of its rotational axis;
A drive motor for turning a turning base on which the grindstone, the second moving mechanism part and the third moving mechanism part are placed around a contact position of the workpiece and the grindstone;
A controller for controlling the first, second and third moving mechanism units and the drive motor;
The grinding wheel, the an outer peripheral surface to perform contact with a workpiece surface, so the cylindrical portion for performing curved surface portion and the finishing of the concave curved surface shape for performing roughing a disc shape is formed A spherical surface generating device characterized by having   2. The spherical surface generating device according to claim 1, wherein the grindstone is a grindstone material in which the curved surface shape portion and the cylindrical portion are different. In the spherical surface creation method of creating a spherical surface on the workpiece by rotating the workpiece held by the workpiece holder and bringing the rotating grindstone into contact with the workpiece surface,
Forming a concave curved surface shape portion for roughing in the direction of the rotation axis on the outer peripheral surface of the grindstone and a cylindrical portion for performing finishing , the work rotation shaft held by a work holder and the grindstone The workpiece and the grindstone are rotated in a state where the rotation axis of the workpiece is orthogonal to each other, the top of the workpiece on the rotation axis and the curved surface shape portion on the outer peripheral surface of the grindstone are brought into contact with each other, and the spherical surface formed by the curved shape portion on the top of the workpiece The shape is processed, and then the workpiece and the grindstone are moved relative to each other so that the cylindrical portion of the grindstone faces the rotation axis of the workpiece. And creating a spherical surface on the workpiece by turning the grindstone around the vicinity of the contact position.

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