JP2870964B2 - Curved surface processing equipment - Google Patents

Description

The present invention relates to a special lens or the like in which a toric surface, that is, a curvature in a direction orthogonal to a special lens or the like is different from each other, and a cross-sectional shape of each curvature is represented by an aspheric surface instead of a spherical surface. The present invention relates to a curved surface processing apparatus.

2. Description of the Related Art Conventionally, processing of a lens having a toric surface (hereinafter referred to as a toric lens) is performed by forming a square rod-shaped or spherical surface having an approximate radius of curvature on an outer periphery of a rotatable wheel 42 as shown in FIG. A pre-ground workpiece 41 is attached to the workpiece 41, and a female jig 43 made of iron, cast iron, stainless steel or the like having a concave toric surface formed on a processing surface on an outer periphery of the workpiece 41 is fixed to a predetermined surface. In this state, the wheel 42 is rotated, and an abrasive such as green silicon carbide abrasive grains # 600 to # 4000 is supplied between the female jig 43 and the processing surface. The female jig 43 is oscillated in a direction perpendicular to the rotation direction of the wheel 1 while lapping is performed by sequentially reducing the particle size of the abrasive grains. In the finishing step, the female jig 43 is made of polyurethane or the like. When you attach a polisher Moni, supplied cerium oxide abrasive grains 1μm about size, it had done polishing in the same operation.
The female jig 43 has an appropriate length, and is supported so as to be swingable in the width direction by engaging the tips of a pair of pressing needles 44 at both ends thereof, and Since the pressing needle 44 is fixed to both ends of a swinging rod 45 that can swing in the longitudinal direction of the female jig 43, it is swingably supported also in the longitudinal direction. The swinging rod 45 is urged toward the axis of the wheel 42 and is swingably attached to an operating arm 46 that can be reciprocated in the axial direction of the wheel 42.

Problems to be Solved by the Invention However, in such a lapping and polishing method, hand-made intuition and skilled skills are required for high-precision processing, so that productivity is extremely low, and not only costs are increased, but also the cost of the lens is increased. There is a problem that it is theoretically impossible to make the generatrix direction and the sagittal direction aspherical.

Means for Solving the Problems In order to achieve the above object, the present invention comprises a wheel that rotates by attaching a workpiece to an outer periphery, and a rotation detector that detects a rotation speed of the wheel, and an output of the rotation detector. A feed mechanism, in which a feed amount is set by a control unit that inputs a signal, is arranged in a direction perpendicular to the rotation axis of the wheel, and a turning table that turns on an axis perpendicular to the feed direction on the feed mechanism, The turning table is provided with a rotation detector, and a feed mechanism in which a feed amount is set by a control unit that inputs an output signal of the rotation detector is arranged on the turning table, and a processing tool that can be rotationally driven is provided on the feed mechanism. It is characterized by having.

Since the present invention has the above configuration, the distance between the center of rotation of the wheel and the processing point of the processing tool can be changed in one direction by rotating the wheel while rotating the processing tool and reciprocatingly turning the turning table. By moving the feed amount set in the control unit by the wheel rotation detector with the feed mechanism using the wheel rotation detector, the radius of curvature can be made non-uniform, that is, an aspheric surface.
Further, the distance between the turning axis of the turning table and the processing point of the processing tool is defined as a radius of curvature in a direction orthogonal to the one direction, and the feeding amount set in the control unit by the rotation detector of the turning table is further used by the feeding mechanism. By moving it, the radius of curvature can be made aspheric.

Embodiments Hereinafter, embodiments of the present invention will be described with reference to FIGS. 1 to 3. FIG. Reference numeral 1 denotes a workpiece to be processed into a toric lens, which is attached and fixed to an outer peripheral portion of a wheel 2 rotatably supported around a horizontal axis. The wheel 2
Is mounted on one end of a rotary spindle 5 rotatably supported by a support 4 installed on the base 3, and the other end of the rotary spindle 5 is driven by a drive motor 6 installed on the base 3. It is configured to be rotationally driven via a drive belt 7. Thus, wheel 2 is 10-200r.p.
It is driven to rotate at a rotation speed of about m. An outer peripheral portion of the wheel 2 is formed in a polygonal shape so that the bottom surfaces of the plurality of workpieces 1 are placed thereon, and a positioning flange 8 on one side of which a side surface of the workpiece 1 abuts is formed. On the other side, a fixing bolt 9 for pressing the other side surface of the workpiece 1 is provided.

A guide rail 10 is provided on the base 3 at a position below the wheel 2 in a direction perpendicular to the rotation axis thereof. The guide rail 10 is movably supported along the guide rail 10 and has a drive motor. A slide table 13 that can be driven by 11 and a drive screw 12 is provided. A turning table 14 is provided on the slide table 13 such that a turning center is located on a center line in a direction perpendicular to a rotation axis of the wheel 2. It is configured to be able to turn back and forth. A guide rail 18 extending in the direction of the perspective of the rotation axis of the wheel 2 is disposed on the turntable 14. The guide rail 18 is movably supported along the guide rail 18, and is driven by a drive motor 19. A movable base 21 that can be driven by screws 20 is provided. And this mobile platform 21
In addition, a processing tool 22 that can be driven to rotate about an axis parallel to the turning axis of the turning table 14, that is, an axis parallel to the axis perpendicular to the rotation axis of the wheel 2 is provided. I have.
The processing tool 22 is attached to one end of a spindle of a driving device 23 capable of rotating at a high speed of about 30,000 rpm.

A wheel rotation detector 24 is attached to the rotary spindle 5, and a rotation detection signal of the wheel 2 obtained from the wheel rotation detector 24 is taken into a feed amount controller 25, and a position control signal is given to the drive motor 11. A rotation table rotation detector 26 is attached to the drive motor 17 of the rotation table 14, and a rotation detection signal obtained from the rotation table is taken into the feed amount control unit 27, and the position control signal is sent to the drive motor 19. give.

In the above configuration, the wheel 12 is rotated by the drive motor 6, and the drive motor 17 is rotated forward and reverse to reciprocate the turning table 14 within a predetermined angle range, and
Is rotated at high speed by the driving device 23. At this time, wheel 2
The workpiece 1 on the outer periphery of the workpiece 2 has a radius of curvature R corresponding to the distance between the rotation center 0 of the wheel 2 and the processing point, and the rotation center P of the rotation table 14 and the It is processed into a curved surface having a radius of curvature r corresponding to the distance from the processing point. Further, a feed amount control unit 25 numerically controls the drive motor 11 in accordance with the indexing angle of the wheel 2 by a wheel rotation detector 24 attached to the rotary spindle 5, and a processing point between the processing tool 22 and the workpiece 1. Is changed so that the radius of curvature is not constant R, that is, R is made aspherical. In a direction orthogonal to this, a rotation detector 26 of the turning table attached to the driving motor 17 of the turning table is provided.
Thus, the feed amount control unit numerically controls the drive motor 19 in accordance with the indexing angle of the turning table, changes the processing point between the processing tool 22 and the workpiece 1, and makes the curvature radius r aspherical. it can.

According to the free-form surface processing apparatus of the present invention, the wheel is rotated while the processing tool is rotated as described above, the turning table is reciprocated, and the processing point is moved according to each rotation angle. Accordingly, it is possible to process a curvature having a curved surface represented by a formula of two orthogonal aspheric surfaces.

[Brief description of the drawings]

1 is a configuration diagram of a curved surface processing apparatus according to an embodiment of the present invention, FIG. 2 is a plan view of the same, FIG.
4B is a plan view of the main part, FIG. 4A is a cross-sectional view of the main part of a conventional processing apparatus, and FIG. 4B is a front view of the same. 1 Workpiece, 2 Wheel, 13 Slide table, 14 Rotating table, 21 Moving table, 22 Processing tool, 24 Rotation detector, 25 Feed amount control unit , 26 ...
... Rotation detector, 27 ... Sending amount control unit.

Claims (1)

(57) [Claims] 1. A wheel which rotates by attaching a workpiece to an outer periphery, and a rotation detector for detecting a rotation speed of the wheel, and a feed amount is controlled by a control unit which inputs an output signal of the rotation detector. A feed mechanism is disposed in a direction perpendicular to the rotation axis of the wheel, and a turntable that turns on the feed mechanism about an axis perpendicular to the feed direction, and a turn detector is provided on the turn table. Characterized in that a feed mechanism whose feed amount is controlled by a control unit for inputting an output signal is arranged on a swivel table, and a processing tool is rotatably arranged on the feed mechanism. .