JP4347374B2 - Lens processing equipment - Google Patents

Description

  The present invention relates to a lens processing apparatus that performs spherical processing or the like by performing a predetermined motion such as a swing motion while pressing a processing tool such as a grinding tool against a lens material to be processed.

  In a lens processing apparatus, for example, a lens grinding apparatus that performs curved surface processing on a lens, a grinding mechanism is swung with respect to a lens material to be processed using a cam mechanism. A spherical grinding device using a cam mechanism is disclosed in Patent Document 1.

The grinding device disclosed herein includes a reference cam having a cylindrical curved cam surface, two cam followers that move along the cylindrical curved surface of the reference cam, an oscillating body supported by the cam follower, and an oscillating body supported by the oscillating body. Equipped with a polishing dish. One drive-side cam follower is moved along the cam surface by the drive device, and the other cam follower is moved along the cam surface following the movement of the drive-side cam follower. The dish is swung along a swinging locus corresponding to the shape of the cam surface.
Japanese Examined Patent Publication No. 7-61606

  In a rocking mechanism using a cam, the rocking trajectory of the rocking body and the polishing dish is determined according to the shape of the cam surface. Therefore, the polishing dish is rocked along a rocking angle exceeding this locus or a different rocking locus. In order to achieve this, it is necessary to replace the cam. Such a grinding apparatus is suitable when processing a large amount of the same shape.

  However, since cams must be frequently exchanged when producing small lots and various types, the setup time is lost, and the operating efficiency of the processing apparatus is greatly reduced. In addition, in order to perform curved surface processing of various shapes, it is necessary to prepare a reference cam corresponding to each shape, which increases the manufacturing cost.

  In view of the above-described problems, an object of the present invention is to propose a lens processing apparatus that can perform various curved surface processing without performing parts replacement work such as cam replacement.

The lens processing apparatus of the present invention is
A first X-axis table and a second X-axis table that are movable along the X-axis direction while maintaining a constant interval in the Y-axis direction orthogonal to the X-axis;
A first Y-axis table mounted on the first X-axis table so as to be movable in a Y-axis direction orthogonal to the X-axis;
A second Y-axis table mounted on the second X-axis table so as to be movable in the Y-axis direction;
A first connecting portion that is connected to the first Y-axis table so as to be rotatable about a first central axis extending in a Z-axis direction orthogonal to the X-axis and the Y-axis; and the second Y-axis table A link table comprising a second connecting portion connected in a rotatable manner around a second central axis extending in the Z-axis direction with respect to
A tool spindle mounted on the link table in a state extending in a direction perpendicular to the Z axis;
Processing tools such as grinding tools attached to the tip of this tool spindle,
First driving means for moving the first X-axis table in the X-axis direction;
Second driving means for moving the first Y-axis table in the Y-axis direction;
And third driving means for moving one of the second X-axis table and the second Y-axis table in the X-axis or Y-axis direction, which is the direction in which the table can move. It is a feature.

  In the lens processing apparatus of the present invention, two sets of the X-axis table and the Y-axis table are arranged, and the Y-axis tables are connected to each other by the link table. Therefore, using the first to third driving means, each set of the X-axis table and the Y-axis table is moved in the X-axis and Y-axis directions so that one point on the link table is parallel to the X-axis and the Y-axis. It can be moved along an arbitrary curved locus on a simple plane. That is, the processing tool attached to the tool spindle facing the Z-axis direction mounted on the link table can be moved along an arbitrary curve on a plane parallel to the X-axis and the Y-axis. Therefore, it is possible to perform spherical processing of the lens by swinging the processing tool without using a cam mechanism. In addition, the movement trajectory of the processing tool can be changed by changing the movement amount and movement timing of each set of the X-axis table and the Y-axis table by each driving means. For example, the NC control method can set or change the movement trajectory corresponding to the final shape of the lens surface so that the processing tool draws, and performs cam replacement work as in the case of a swing mechanism using a cam mechanism. There is no need.

  Here, in order to cause the processing tool attached to the tool spindle to swing over a predetermined angular range, the rotation axis of the tool spindle is the first central axis of the link table and the first spindle. What is necessary is just to mount in the said link table so that it may correspond to the perpendicular of the said line segment which passes along the midpoint of the line segment which connects a 2nd center axis line.

  When used as a spherical surface processing apparatus, the first to third driving means are driven and controlled so that the tool spindle swings about a point on the extension line of the rotation center line of the tool spindle as a swing center. A control means and a lens holder for pressing the lens material to be processed against the processing tool may be provided, and the swing center may be positioned on the rotation center line of the lens holder.

  The lens processing apparatus of the present invention employs a configuration in which two sets of an X-axis table and a Y-axis table are arranged, the Y-axis tables are connected to each other by a link table, and a tool spindle is mounted on the link table. By moving each table using the first to third driving means, the processing tool attached to the tool spindle mounted on the link table can be moved along an arbitrary movement locus.

  Therefore, according to the present invention, it is possible to change the movement trajectory of the processing tool without performing cam replacement work. In addition, since an arbitrary curved trajectory of the processing tool can be realized only by position control of the X-axis table and the Y-axis table, it is possible to quickly and easily respond to changes in the processing shape. Therefore, it is possible to realize a lens processing apparatus capable of producing a small lot and a variety of products without causing a decrease in operating efficiency.

  Furthermore, since a high-resolution gear type reduction mechanism as in the case of using a cam mechanism is not required, the configuration of the apparatus can be made simple and inexpensive.

  Furthermore, since conical surface processing, aspherical surface processing, and the like can be performed, a highly versatile lens processing apparatus that can be used as a curve generator can be realized.

  Embodiments of a lens processing apparatus to which the present invention is applied will be described below with reference to the drawings.

(overall structure)
FIG. 1 is a schematic configuration diagram showing a main part of a spherical grinding apparatus for grinding an optical spherical lens to which the present invention is applied. The spherical grinding device 1 has a lens holder 2 for holding a lens material W to be processed, and this lens holder 2 is attached downward to the lower end of a lens shaft 3 arranged vertically. ing. The lens shaft 3 is held by a liftable lens shaft arm 4 in a rotatable state.

  Below the lens holder 2, a grinding tool 5 for performing spherical grinding on the lens material W held by the lens holder 2 is arranged in an upward state. The grinding tool 5 has a concave spherical grinding surface 5 a, and this grinding tool 5 is attached to the upper end of the tool spindle 6. The tool spindle 6 is rotationally driven by a machining shaft motor 7. Further, the tool spindle 6 is swung within a predetermined angular range about a swing center positioned on an extension line of the lens rotation center line 2a of the lens holder 2 by a swing mechanism 10 described below. . Further, the rocking motion of the tool spindle 6 by the rocking mechanism 10 and, therefore, the rocking motion of the grinding tool 5 attached to the tip thereof is controlled by the NC control panel 50.

(Swing mechanism)
The swing mechanism 10 includes a first X-axis table 13 and a second X-axis table 14 that are slidably mounted in the X-axis direction via a pair of upper and lower X-axis linear guide mechanisms 11 and 12 on a vertical surface of a device frame (not shown). It has. The X axis is a horizontal axis in this example, and the first and second X axis tables 13 and 14 are arranged in parallel on the left and right. The first and second X-axis tables 13 and 14 have the same shape and are rectangular plates that are long in the vertical direction and have a certain thickness. The X-axis linear guide mechanisms 11 and 12 are known ones including a guide rail and a slider that slides along the guide rail.

  A first Y-axis table 16 is attached to the vertical surface 13a of the first X-axis table 13 via a Y-axis linear guide mechanism 15 extending in the vertical direction so as to be slidable in the Y-axis direction. Similarly, a second Y-axis table 18 is slidably attached to the vertical surface 14a of the second X-axis table 14 via a Y-axis linear guide mechanism 17 extending in the vertical direction. The first and second Y-axis tables 16 and 18 have the same shape and are rectangular plates that are long in the vertical direction and have a constant thickness. The Y-axis linear guide mechanisms 15 and 17 can also use known mechanisms.

  The first and second Y axis tables 16 and 18 are connected to each other by a link table 19. The link table 19 is a substantially pentagonal plate with a constant thickness, and the first Y-axis table 16 and the first Y-axis table 16 via the first link shaft 23 and the second link shaft 24, respectively, at symmetrical positions on both sides of the symmetry axis. The second Y axis table 18 is connected. The first and second link shafts 23 and 24 are fixed perpendicularly to the vertical surfaces 16a and 18a of the first and second Y-axis tables 16 and 18, and their shaft ends are connected via bearings 25 and 26, respectively. It is connected to the link table 19 in a rotatable state. Center axis lines 23a and 24a of the first link shaft 23 and the second link shaft 24 extend in the Z-axis direction orthogonal to the X-axis and the Y-axis. Accordingly, the link table 19 rotates around the central axes 23a and 24a via the first link shaft 23, the first connecting portion 23A including the bearing 25, and the second link shaft 24 and the second connecting portion 24A including the bearing 26. It is connected to the first and second Y-axis tables 16 and 18 in a free state.

  A spindle holding case 27 is attached to the vertical surface 19a of the link table 19, and the tool spindle 6 is held by the spindle holding case 27 in a rotatable state. Further, the machining shaft motor 7 is attached to the side surface of the spindle holding case 27. In this example, the rotation axis 6a of the tool spindle 6 has a line segment that passes through the midpoint O of the line segment L that connects the center axis line 23a of the first connecting portion 23A and the center axis line 24a of the second connecting portion 24A. It is attached to match the perpendicular.

  Here, the X-axis linear guide mechanisms 11 and 12 of the first and second X-axis tables 13 and 14 are provided with a single X-axis motor 31 for moving the second X-axis table 14 in the X-axis direction. . On the other hand, the Y-axis linear guides 15 and 17 of the first Y-axis table 16 and the second Y-axis table 18 are provided with Y-axis motors 32 and 33 for individually moving in the Y-axis direction.

  FIG. 1 shows the position of the swing mechanism 10 in the neutral state. In the neutral state, the first and second X-axis tables 13 and 14 on the left and right sides are arranged at symmetrical positions at regular intervals across the vertical lens rotation center line 2a. The left and right first and second Y-axis tables 16 and 18 are arranged at the same height, and the rotation center line 6a of the tool spindle 6 mounted on the link table 19 connecting them is vertical. It extends (extends in the Y-axis direction) and coincides with the lens rotation center line 2a.

  As described below, the X-axis motor 31 and the Y-axis motors 32 and 33 are driven by the NC control panel 50 to move the second X-axis table 14 in the X-axis direction, and the first and second Y-axis tables 16, By individually moving 18 in the Y direction, the tool spindle 6 can be oscillated about the oscillating center, whereby the spherical grinding surface 5a of the grinding tool 5 attached to the upper end of the tool spindle 6 can be moved. The lens material W can be subjected to spherical grinding by swinging motion.

(Operation of swing mechanism)
FIG. 2 and FIG. 3 are explanatory views when the grinding tool 5 is caused to swing on the vertical plane parallel to the X axis and the Y axis by the swing mechanism 10.

  First, referring to FIG. 2, P0 and P2 are points indicating the positions of the central axis 24 a of the second link shaft 24 and the central axis 23 a of the first link shaft 23 of the link table 19. A symbol T is a swing locus of these points P0 and P2. The rocking center of the rocking locus T is P, and the rocking radius is R. As described above, the rotation center line 6a of the tool spindle 6 is orthogonal to the line segment L connecting P0 and P2, and coincides with the straight line OP passing through the midpoint O of the line segment L. 2A is a distance between the central axes 23a and 24a, and the length B of the straight line OP, that is, the position of the swing center P is set according to the shape of the processed curved surface.

  When the link table 19 is rotated by an angle δ around the swing center P from the state where the positions of the link shafts 24 and 23 are at the positions P0 and P2, the link shafts 24 and 25 move to P1 and P3. As described above, the link table 19 is moved so that the link shafts 24 and 23 move on the swinging trajectory T having the radius R centered on P, thereby having the arc-shaped cam surface having the radius R which has been conventionally used. In a grinding apparatus using a reference cam, a swing member having the same shape as the link table 19 is installed on the cam surface, and two cam followers attached at the same position as the link shafts 24 and 23 are disposed along the cam surface. It is possible to cause the link table 19 to perform the same movement as when moving.

Here, with reference to FIG. 3, when the link table 19 is rotated about the swing center P by the angle δ, the movement amounts of the link shafts 24 and 23 are obtained by rotating the XY coordinates by the angle δ. This corresponds to coordinate conversion to x′y ′ coordinates. The converted x′y ′ coordinates are as shown in the following equations (1) and (2).
x ′ = x cos δ + ysin δ (1)
y ′ = − xsin δ + y cos δ (2)

When the variables shown in FIG. 2 are applied to these equations, the coordinates (x1, y1) of P1 are as shown by the following equations (3) and (4).
x1 = A cos δ−B sin δ (3)
y1 = −Asinδ−Bcosδ (4)

Similarly, the coordinates (x2, y2) of P3 are as shown by the following expressions (5) and (6).
x2 = −A cos δ−B sin δ (5)
y2 = Asinδ−Bcosδ (6)

Therefore, the movement amount (Δx1, Δy1) of the link shaft 24 in the X-axis direction and the Y-axis direction when the link table 19 is swung so as to move the link shafts 24, 23 from P0 and P2 to P1 and P3. Is as shown in the following equations (7) and (8).
Δx1 = −A + A cos δ−B sin δ (7)
Δy1 = B−Asinδ−Bcosδ (8)

Similarly, the amount of movement (Δx2, Δy2) of the link shaft 23 in the X-axis direction and the Y-axis direction is as shown in the following equations (9) and (10).
Δx2 = −A + A cos δ−B sin δ (9)
Δy2 = B−Asinδ−Bcosδ (10)

  Here, the second Y-axis table 18 and the first Y-axis table 16 are connected to the link shafts 24 and 23, respectively. When the rotation about the swing center P of the link table 19 is performed based on the drive control of the second and first Y-axis tables 18 and 16, first, the link shaft 24 on the second Y-axis table 18 side is set to P0. The second Y-axis table 18 is moved by the X-axis motor 31 and the Y-axis motor 33 in the X-axis and Y-axis directions. On the other hand, in order to move the link shaft 23 on the first Y-axis table 16 side from P2 to P3, the first Y-axis table 16 is moved in the Y-axis direction by the Y-axis motor 32, and the center Y of the link shaft 23 is moved. Coordinates are made to coincide with y2 shown by the equation (6). The X coordinate of the center of the link shaft 23 is determined by the follower of the first X axis table 13.

  The point where the X coordinate of the center of the link shaft 23 is determined by the follow will be described in more detail. First, when the Y coordinate of the center of the link shaft 23 of the first Y axis table 16 is moved to y2, the distance in the Y axis direction of the first and second Y axis tables 16, 18 (the Y axis direction of the link shafts 24, 23) With respect to the distance D), the relationships shown by the following expressions (11) and (12) are established based on the above expressions (4) and (6).

D = Asinδ−Bcosδ − (− Asinδ−Bcosδ) (11)
sin δ = D / 2A (12)

Here, referring to FIGS. 2 and (12), the distance 2A is a distance between the link shafts 24 and 23 and is a predetermined value. Further, by moving the coordinates of the first Y-axis table 16 to y2, the line segment L connecting the link shafts 24 and 23 is rotated by an angle δ. As a result, for the distance in the X-axis direction of the second and first Y-axis tables 18 and 16 (distance C in the X-axis direction of the link shafts 24 and 23), the relationship expressed by the following equation (13) is established. That is, the X coordinate of the first Y-axis table 16 is uniquely determined. In addition, the value of this (13) formula corresponds with the value of C at the time of calculating using said (3) Formula and (5) Formula.
C = 2A cos δ (13)

  Thus, the first Y-axis table 16 only needs to be independently driven only in the Y-axis direction, and the coordinates in the X-axis direction are uniquely determined based on other coordinates, member dimensions, and the like.

(Other embodiments)
In the above embodiment, one X-axis motor 31 and two Y-axis motors 32 and 33 for independently moving the first and second Y-axis tables 16 and 18 are provided. Instead of this, two X-axis tables that move the first and second X-axis tables 13 and 14 independently and one Y-axis table that moves one of the first and second Y-axis tables 16 and 18 are used. You may arrange.

  In the above embodiment, the present invention is applied to a lens spherical surface processing apparatus. The present invention can also be applied to a lens processing apparatus for processing a curved surface other than a spherical surface. For example, the lens material W can be conical processed by moving the processing tool along the conical surface. Further, as with the curve generator, aspherical processing can be performed.

It is a schematic block diagram of the lens grinding apparatus to which this invention is applied. It is explanatory drawing which shows operation | movement of the rocking | fluctuation mechanism of the lens grinding apparatus of FIG. It is explanatory drawing which shows operation | movement of the rocking | fluctuation mechanism of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Spherical grinding apparatus 2 Lens holder 2a Lens rotation center line 3 Lens axis 4 Lens axis arm 5 Grinding tool 6 Tool spindle 6a Rotation center line 7 Processing axis motor 10 Oscillation mechanism 11, 12 X-axis linear guide mechanism 13 1st X-axis Table 14 2nd X-axis table 15, 17 Y-axis linear guide mechanism 16 1st Y-axis table 18 2nd Y-axis table 19 Link table 23 1st link shaft 24 2nd link shaft 23A 1st connection part 24A 2nd connection part 23a, 24a Center axis 25, 26 Bearing 27 Spindle holding case 31 X-axis motor 32, 33 Y-axis motor 50 NC control panel P Oscillation center W Lens material

Claims (3)

A first X-axis table and a second X-axis table movable in the X-axis direction;
A first Y-axis table mounted on the first X-axis table so as to be movable in a Y-axis direction orthogonal to the X-axis;
A second Y-axis table mounted on the second X-axis table so as to be movable in the Y-axis direction;
A first connecting portion that is connected to the first Y-axis table so as to be rotatable about a first central axis extending in a Z-axis direction orthogonal to the X-axis and the Y-axis; and the second Y-axis table A link table comprising a second connecting portion connected in a rotatable manner around a second central axis extending in the Z-axis direction with respect to
A tool spindle mounted on the link table in a state extending in a direction perpendicular to the Z axis;
Processing tools such as grinding tools attached to the tip of this tool spindle,
First driving means for moving the first X-axis table in the X-axis direction;
Second driving means for moving the first Y-axis table in the Y-axis direction;
And third driving means for moving one of the second X-axis table and the second Y-axis table in the X-axis or Y-axis direction, which is the direction in which the table can move. A lens processing device. The lens processing apparatus according to claim 1,
The lens processing characterized in that a rotation center line of the tool spindle coincides with a perpendicular line of the line segment passing through a midpoint of a line segment connecting the first center axis line and the second center axis line in the link table. apparatus. The lens processing apparatus according to claim 2,
Control means for driving and controlling the first to third driving means to swing the tool spindle about a point on an extension line of the rotation center line of the tool spindle as a swing center;
A lens holder for pressing the lens material to be processed against the processing tool,
A lens processing apparatus, wherein the swing center is located on a rotation center line of the lens holder.

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