JPH01159146A - Work holding device - Google Patents

Abstract

PURPOSE:To maintain the stable polishing and high surface precision by reducing the turning moment around a bearing set between a work supporting housing and an intermediate flange which is due to the polishing resistance generated on the worked surface of a work. CONSTITUTION:The center O of curvature of a convex lens 17 is set so as to coincide with the revolution axis of a bearing 15, namely the axis line of a work holding shaft 18, and the revolution axis Z of the lens 17 passing through the spherical core O and the X-plane passing through the center of an O-ring 13 crosses at the point S, and the S point is set so as to be positioned under the lens 17. Further, the crossing point of the axis line of the supporting shaft 18 and the worked plane 17a of the lens 17, namely the horizontal plane h0 including the surface top of the lens 17 is set so as to coincide with the horizontal plane h1 including the center part of the bearing 15. Therefore, the generation of the turning moment around the bearing 15 which is caused by the polishing resistance formed on the worked surface 17a of the lens 17 during polishing work can be prevented, and the generation of vibration on the lens 17 during the polishing work can be prevented, and the stable polishing work is permitted.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a work holding device used in an optical element polishing machine.

[Prior Art] A conventional work holding device 1 is shown in FIG. The above-mentioned workpiece holding device consists of a stay 2 fixed to a processing machine (not shown).
A housing 6 is held at the lower end of the housing 6 via an elastic member. A workpiece support shaft 8, which holds a workpiece 7 at its tip end, is rotatably supported in the center of the housing 6 via a bearing 5.

Here, when the horizontal plane perpendicular to the workpiece rotation axis Z and including the intermediate part of the height of the bearing 5 is h+, and the horizontal plane including the intersection of the workpiece rotation axis Z and the workpiece machining surface 7a is If the distance H between the planes he and h+ is sufficiently small, the rotational moment about the bearing 5 caused by the polishing resistance force will be small, allowing stable polishing and a high degree of area.

[Problems to be Solved by the Invention] However, in the conventional workpiece holding device described above, when polishing a convex workpiece, a polishing tool (not shown) is required.
In order to avoid interference with the housing upper part 6a, it is impossible to set the distance H between the horizontal planes and h to a sufficiently small value. In other words, the bearing 5 of the workpiece support shaft 8 is connected to the workpiece machining surface 7.
Since it is not possible to get close enough to point a, the polishing resistance force generated on the workpiece processing surface 7a during polishing creates a moment with the bearing 5 as a fulcrum due to the backlash in the bearing 5, and the length of the workpiece support shaft 8 and the lens Vibrations that were magnified (increased) occurred in the workpiece 7 due to the distance H corresponding to the thickness, making it difficult to obtain stable and high surface accuracy.

Therefore, the present invention has been made with a focus on the above-mentioned problems, and it is possible to stably polish even a convex workpiece without receiving rotational moment due to polishing resistance force, and obtain high surface accuracy. It is an object of the present invention to provide a workpiece holding device for an optical element polishing machine that can perform the following steps.

[Step F for Solving the Problems] FIG. 1 is a conceptual diagram showing the configuration of a workpiece holding device 11 according to the present invention. As shown in the figure, the workpiece holding device 11 consists of a stay 1 fixed to the upper shaft (not shown) of the ball core polishing machine.
2, a flange I4 held at the lower end of the stay 12 via an elastic member 13 so as to be able to move slightly in the up-down direction, front-back direction, etc., and a bearing 15 at the end of the flange 14 opposite to the elastic member 13. The workpiece support shaft I8 is fixed to the center of the housing 16 and holds the workpiece 17 at its tip. The distance between the intersection point S of the tangent at P and the rotational axis Z of the workpiece 17 and the horizontal plane The horizontal plane including the intersection with the surface 17a and the horizontal plane h1 including the intermediate portion of the bearing 15 are brought close to each other (coinciding in the figure), and further so that the center of curvature 0 of the work 17 passes through the work rotation axis Z. It is configured.

[Function] In the above configuration, the horizontal surface including the bearing 15,
The distance H between the workpiece rotation axis Z and the horizontal plane including the intersection of the workpiece processing surface 17a can be matched, that is, the distance H can be made sufficiently small.

Therefore, by reducing the distance H, the rotational moment about the bearing 15 due to the machining (polishing) resistance force generated on the workpiece machining surface 17a can be made as small as possible, and the vibration of the workpiece 17 during machining (polishing) can be minimized. can be made smaller.

[Example] Hereinafter, an example of the present invention will be described in detail using the drawings.

(First Embodiment) FIG. 2 shows a first embodiment of the workpiece holding device 11 according to the present invention.

In the drawing, reference numeral 12 indicates a stay fixed to the upper shaft of the polishing machine (not shown), and a ring-shaped flange 14 is supported by bolts 19 at the lower end of the stay 12. A hole 20 with a diameter larger than that of the bolt 19 is bored in this flange 14, and the bolt 19 is loosely fitted into this hole 20, and the threaded portion 19a of the bolt 19 and the lower end of the stay 12 are screwed together. An O-ring (elastic member) 13 is interposed between the contact surfaces of the flange 12 and the flange 14, and the flange 14 can be slightly moved in the up-down direction, front-back direction, etc. with respect to the stay 12 via the O-ring 13. possible to be retained. A bearing 15 is held at the end of the inner ring side 14a of the ring-shaped flange 14 via a bearing stop 21, and the bearing stop 21 is fixed to the ring-shaped flange 14 with a screw 22. A cup-shaped housing 16 is fixed to the inner ring of the bearing 15 by a bearing retainer 23, and the housing 16 is rotatably held with respect to the flange 14. In the center of the housing 16, a workpiece support shaft (applied plate) 18, which has a convex lens (workpiece) 17, which is a workpiece, adhered to its tip end, is fixedly screwed. The center of curvature (spherical center) O of the convex lens I7 is set to coincide with the rotation axis of the bearing 15, that is, the axis of the workpiece support shaft 18. Further, the rotation axis Z of the convex lens 17 passing through the spherical core 0 and the X plane passing through the center of the O-ring 13 intersect at one point S, and these eight points are set to be located below the convex lens 17.

In addition, the axis of the workpiece support shaft 18 and the machining surface 1 of the convex lens 17
The intersection point 7a, that is, the horizontal plane that includes the top of the surface of the convex lens 17, is set to coincide with the horizontal plane h+ that includes the center portion of the bearing 15.

According to the above configuration, generation of a rotational moment about the bearing 15 due to the polishing resistance force generated on the processed surface 17a of the convex lens 17 during polishing can be prevented. As a result, the convex lens 17 during polishing does not vibrate, and stable polishing can be performed.

(Second Embodiment) FIG. 3 shows a second embodiment of the workpiece holding device 25 according to the present invention. This embodiment is constructed by replacing the workpiece 17 shown in the first embodiment with a concave lens 26. Hereinafter, the same components as those in the first embodiment will be given the same numbers and their explanation will be omitted. do.

The center of curvature (spherical center) 0 of the concave lens (workpiece) 26 is set to coincide with the rotation axis of the bearing 15, that is, the axis of the workpiece support shaft 18.

Further, the rotation axis Z of the concave lens 26 passing through the spherical center 0 and the X plane passing through the center of the O ring (elastic member) 13 intersect at a point S, and this point S is set to be located above the concave lens 26. It is.

Further, the intersection of the axis of the workpiece support shaft 18 and the processed surface 26H of the concave lens 26, that is, the horizontal plane h@ including the top of the surface of the concave lens 26, is set to coincide with the horizontal plane including the center of the bearing 15. be.

According to the above configuration, similarly to the first embodiment, the concave lens 2
It is possible to prevent generation of a rotational moment about the bearing 15 due to the polishing resistance force generated on the machined surface 26a of the bearing 15. As a result, stable polishing can be performed without vibration of the concave lens 26 during polishing.

(Third Embodiment) FIG. 4 shows a third embodiment of the workpiece holding device 30 according to the present invention.

The workpiece holding device 30 of this embodiment is configured such that the horizontal planes h- and h+ are brought close to each other, instead of making the horizontal planes h- and h- coincide with each other as in the first and second embodiments. In the figure, only the workpiece 31 is shown, and other stays, flanges, housings, workpiece support shafts, etc. are omitted because they have the same structure as the first and second embodiments. That is, in this embodiment, the workpiece holding device 30 is arranged so that the intersection point S between a tangent at a point P on the outer periphery of the workpiece 31 and the rotational axis Z of the workpiece 31, a horizontal plane including the point P, and the workpiece rotational axis. A horizontal plane including the center of the bearing (see 15 in Fig. 1) is set within a distance l from the intersection S with 2, and a horizontal plane including the top of the surface of the workpiece 31 is set at the above distance! It is configured to be set at an intermediate position.

According to the above configuration, even if the horizontal planes ha and h cannot be made to coincide due to design considerations of the workpiece holding device, the bearing due to the polishing resistance force generated on the machined surface 31a of the workpiece 31 during the polishing process can be prevented. Since the generation of rotational moment around the center can be sufficiently reduced, the same effects as in the first and second embodiments can be obtained.

[Effects of the Invention] According to the present invention, a flat lens, a nearly flat lens, a convex lens,
Capable of holding concave lenses and other workpieces accurately, suppressing vibrations of the workpiece due to processing resistance, enabling stable processing and processing of optical elements with high surface accuracy. .

[Brief explanation of the drawing]

FIG. 1 is a conceptual diagram of a work holding device according to the present invention, and FIG.
3 is a partial sectional view showing a second embodiment of the work holding device according to the present invention, and FIG. 4 is a partial sectional view showing the first embodiment of the work holding device according to the present invention. FIG. 5 is an explanatory diagram showing the third embodiment of the work holding device according to the invention.
FIG. 2 is an explanatory diagram of a prior art. 11... Work holding device 12... Stay 13... Elastic member 14... Flange 15... Bearing 16... Housing 17... Work 17a... Work machining surface 18... Work Support axis, h,...Horizontal plane P...1 point S...Intersection point X...Horizontal plane Z...Work rotation axis ■8...Work Bunkari Tsukuda No. 2 Figure Figure 4

Claims (1)

[Claims] (1) A stay fixed to a processing machine, a flange held at the lower end of the stay via an elastic body, and a housing held at the opposite end of the elastic body in contact with the flange via a bearing. , a workpiece support shaft provided in the center of the housing, and a central portion of an elastic body provided at the intersection of a tangent at one point on the outer periphery of the workpiece and the rotational axis of the workpiece and the lower end of the stay. The distance between the bearing and the horizontal plane including the intermediate portion of the bearing is set close to or coincident with each other, and the distance between the intersection of the workpiece rotation axis and the workpiece machined surface and the horizontal plane including the intermediate portion of the bearing is set close to or coincident with each other. Work holding device.