JP2008260091A - Polishing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve shape accuracy in a polishing object surface, by easily reducing uneven polishing of a polishing object, in a polishing device. <P>SOLUTION: This polishing device 100 comprises an upper shaft spindle 12 having a rotor 12a, an upper shaft motor 14, an upper shaft hairpin 6 switchable to a fixing state of fixing a work 3 and an unfixed state of tiltably supporting the work 3 to the rotational axis of the rotor 12a, an upper shaft chuck 10, a lower shaft spindle 13 having a rotor 13a, a lower shaft motor 15, a lower shaft hairpin 8 switchable to a fixing state of fixing a polishing pan 5 and an unfixed state of tiltably supporting the polishing pan 5 to the rotational axis of the rotor 13a, a lower shaft chuck 11, a rocking arm 25 relatively rockably holding the polishing pan 5 around the curvature center, and a control part for performing polishing work by switching a first holding mode and a second holding mode. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a polishing apparatus. For example, the present invention relates to a polishing apparatus that performs surface finish polishing of optical elements such as lenses, prisms, and mirrors made of glass which is a brittle material.

Conventionally, for example, in surface finishing of optical elements such as lenses, prisms, and mirrors, an object to be polished made of these optical elements, and a polishing dish made of an elastic tool for polishing such as pitch, polyurethane pads and polishers, etc. There is known a polishing apparatus that performs a polishing process by applying a sliding motion while pressing with a polishing abrasive grain interposed at an interface.
As such a polishing apparatus, for example, in Patent Document 1, an upper shaft whose axial load is adjusted by a balance weight fixed below is supported by a swing arm so as to be swingable. The support rod provided at the tip is pressed so as to be tilted by the workpiece holding portion that holds the polishing workpiece in contact with the polishing tool, and the swing motion of the upper shaft is transmitted to the workpiece holding portion via the support rod. A polishing machine is described. Although Patent Document 1 does not describe the support state of the polishing tool, in general, the polishing is performed by rotating the polishing tool around the central axis of the polishing surface.
For example, in Patent Document 2, a lens is supported by a holder that is held so as to be swingable and pressed by a shaft having a sphere at the tip, and is supported for rotation about a central axis of a polishing surface. A polishing apparatus is described in which a lens is polished by pressing a tool and swinging a shaft while rotating the tool.
JP-A-8-39425 Japanese Patent Application Laid-Open No. 2005-279983

However, the conventional polishing apparatus as described above has the following problems.
In the techniques described in Patent Documents 1 and 2, both of the objects to be polished are rocked and moved on a polishing tool (polishing dish) while being tiltably held. For this reason, the contact between the object to be polished and the polishing tool and the variation in the force acting between them are reduced to some extent. However, since the processing force due to the rotational peripheral speed of the polishing tool is the minimum at the center of rotation and the maximum at the periphery, uneven wear occurs when the periphery of the polishing tool hits the surface to be polished due to the swing of the workpiece. There is a problem that it is easy to do.
It is conceivable to reduce the rocking angle and prevent uneven wear by preventing the peripheral edge from coming into contact with the surface to be polished. In this case, however, the rocking angle is narrow, resulting in the rotational peripheral speed. Unevenness in processing force cannot be leveled.
Therefore, when performing high-precision polishing using a conventional polishing apparatus, the object to be polished and the polishing tool are appropriately selected according to the finished state of the surface to be polished in order to eliminate the peculiarities that occur on the surface to be polished. The polishing process is also repeated by reversing the arrangement. Such an operation not only requires time and effort to replace the object to be polished and the polishing tool, but also has a problem that it requires a high degree of skill because the placement error affects the polishing accuracy.

  The present invention has been made in view of the above problems, and provides a polishing apparatus that can easily reduce the bias of polishing with respect to an object to be polished and can improve the shape accuracy of a surface to be polished. The purpose is to do.

In order to solve the above problems, in the invention according to claim 1, the polishing dish having a polishing surface made of a convex or concave spherical surface and the surface to be polished of a workpiece are brought into contact with each other and pressurized, and the polishing dish A polishing apparatus for polishing the workpiece by relatively moving the workpiece and the workpiece, the first rotating means having a first rotating shaft portion for rotating the workpiece, and the first rotating shaft portion A fixed state in which the workpiece is fixed to the first rotating shaft portion and a non-fixed state in which the workpiece is tiltably supported with respect to the rotation center axis of the first rotating shaft portion. A first holding means that is possible; a second rotating means having a second rotating shaft part for rotating the polishing dish; and a second rotating shaft part provided on the second rotating shaft part. A fixed state of fixing to the rotating shaft portion of the second rotating shaft portion and the second rotating shaft portion of the polishing dish A second holding means that can be switched to a non-fixed state that is tiltably supported with respect to a rotation center axis, and the first and second rotation means can be relatively swung around the center of curvature of the polishing surface. The first holding means is in a non-fixed state of the first holding means, and the second holding means is in a fixed state of the second holding means. A holding mode; and a second holding mode in which the first holding means is in a fixed state of the first holding means and the second holding means is in an unfixed state of the second holding means. And a control means for performing polishing processing by switching.
According to this invention, in the first holding mode, the workpiece is unfixed by the first holding means, the polishing dish is fixed by the second holding means, and polishing is performed. In the second holding mode, Polishing can be performed with the workpiece held by the first holding means and the polishing dish unfixed by the second holding means. Therefore, in the polishing process in the first holding mode, by rotating the second rotating shaft and operating the swinging means, the polishing dish can be rotated and relatively swung with respect to the workpiece so that it can tilt. The held workpiece can be polished. Further, in the polishing process in the second holding mode, the workpiece is rotated and relatively oscillated with respect to the polishing dish held so as to be tiltable by rotating the first rotating shaft portion and operating the oscillating means. The workpiece can be polished.
As described above, by switching the side that can be tilted in each polishing process, the occurrence position and the degree of occurrence of uneven wear occurring on the workpiece can be changed.

According to a second aspect of the present invention, in the polishing apparatus according to the first aspect, the workpiece can be rotated about the rotation center axis of the first rotation shaft portion in a non-fixed state of the first holding means. The configuration is as follows.
According to this invention, since the workpiece is tiltably and rotatably held in the non-fixed state of the first holding means, the degree of freedom of the posture of the workpiece is increased in the polishing process in the first holding mode. Uneven wear of the workpiece can be reduced.

According to a third aspect of the present invention, in the polishing apparatus according to the first or second aspect, the polishing dish is moved around the rotation center axis of the second rotation shaft portion when the second holding means is not fixed. The structure is made rotatable.
According to this invention, since the polishing dish is tiltably and rotatably held in the non-fixed state of the second holding means, the degree of freedom of the posture of the polishing dish is increased in the polishing process in the second holding mode. Therefore, uneven wear of the polishing dish can be reduced.

According to a fourth aspect of the present invention, in the polishing apparatus according to the first aspect, the first holding means is a first member that locks the workpiece with respect to the rotation direction of the first rotation shaft portion. It is set as the structure provided with the stop means.
According to this invention, the work is locked by the first locking means in the non-fixed state of the first holding means, and rotates together with the first rotary shaft portion in a tiltable state. In the polishing process in the holding mode, the workpiece can be rotated in synchronization with the first rotating shaft portion. Therefore, it is possible to perform a polishing process that performs a stable relative motion between the workpiece and the polishing dish.

According to a fifth aspect of the present invention, in the polishing apparatus according to the first or fourth aspect, the second holding unit locks the polishing dish with respect to the rotation direction of the second rotation shaft portion. It is set as the structure provided with 2 latching means.
According to the present invention, the second holding means is non-fixed and the polishing plate is locked by the second locking means and is rotated together with the second rotating shaft portion in a tiltable state. In the polishing process in the second holding mode, the polishing dish can be rotated in synchronization with the second rotation shaft portion. Therefore, it is possible to perform a polishing process that performs a stable relative motion between the workpiece and the polishing dish.

According to a sixth aspect of the present invention, in the polishing apparatus according to any one of the first to fifth aspects, the first holding means is provided coaxially with the first rotating shaft portion, and the workpiece is covered with the workpiece. A first ridge that is pressed from the back surface side of the polishing surface and is rotatably and tiltably supported with respect to the rotation center axis of the first rotation shaft portion, and the workpiece is supported on the first rotation shaft portion. And a first chuck portion to be fixed.
According to this invention, since the first holding means has the first Kanzashi and the first chuck portion, the first chucking portion fixes the workpiece to the first rotating shaft portion by the first chuck portion, The fixed state of the holding means can be realized, and the non-fixed state can be realized by the first Kanzashi by releasing the fixing by the first chuck portion. Therefore, the fixed state and the non-fixed state of the first holding means can be switched by operating and releasing the operation of the first chuck portion.

According to a seventh aspect of the present invention, in the polishing apparatus according to any one of the first to sixth aspects, the second holding means is provided coaxially with the second rotating shaft, and the polishing dish is A second Kanzashi pressed from the back surface side of the polishing surface and supported so as to be rotatable and tiltable with respect to the rotation center axis of the second rotation shaft portion, and the polishing dish as the second rotation shaft portion The second chuck portion is fixed to the second chuck portion.
According to this invention, since the second holding means has the second kanzashi and the second chuck part, the second chucking unit fixes the polishing dish to the second rotating shaft part by the second chuck part. The fixed state of the holding means can be realized, and the non-fixed state can be realized by the second Kanzashi by releasing the fixation by the second chuck portion. Therefore, the fixed state and the non-fixed state of the second holding means can be switched by the operation and release of the operation of the second chuck portion.

  According to the polishing apparatus of the present invention, the work and the polishing dish are tiltably held by the first and second holding means, respectively, and the side that is tiltably held by the control means is switched, whereby the bias generated in the work is changed. Since the position and degree of occurrence of wear can be changed, it is possible to easily reduce the unevenness of polishing with respect to the object to be polished and to improve the shape accuracy of the surface to be polished.

  Embodiments of the present invention will be described below with reference to the accompanying drawings. In all the drawings, even if the embodiments are different, the same or corresponding members are denoted by the same reference numerals, and common description is omitted.

[First Embodiment]
A polishing apparatus according to a first embodiment of the present invention will be described.
FIG. 1 is a schematic front view showing a schematic configuration of a polishing apparatus according to a first embodiment of the present invention. FIG. 2 is a schematic front view showing a main part of the polishing apparatus according to the first embodiment of the present invention. FIG. 3 is a cross-sectional view showing an example of a workpiece of the polishing apparatus according to the first embodiment of the present invention. FIG. 4 is a partial cross-sectional view showing an example of a polishing dish of the polishing apparatus according to the first embodiment of the present invention.

As shown in FIG. 1, the polishing apparatus 100 of this embodiment performs surface finishing of optical elements such as lenses, prisms, and mirrors having a convex spherical surface or a concave spherical surface, and a workpiece on which a convex spherical surface or a concave spherical surface is formed. In contrast, a polishing dish having a corresponding concave spherical surface or convex spherical surface is brought into contact with the surface to be polished and pressed, and the polishing dish and the work are moved relative to each other to polish the work. This is a ball center polishing apparatus.
Below, it demonstrates centering around the structure and operation | movement of the relative motion mechanism of the workpiece | work and the grinding | polishing dish in the grinding | polishing apparatus 100. FIG. In addition, illustration and description of a well-known mechanism that is naturally provided for performing such polishing processing, such as a polishing liquid supply mechanism, are omitted.

The apparatus main body 20 of the polishing apparatus 100 includes an apparatus main body upper part 20B supported on the apparatus main body lower part 20A, and a processing chamber part 21 for performing polishing is provided at an intermediate part thereof.
In the lower part 20A of the apparatus body, the lower shaft unit 2 provided with the polishing dish 5 in a detachable manner is centered on a point P that coincides with the center of curvature of the polishing surface 5d of the polishing dish 5 in a plane parallel to the drawing sheet. It is provided so as to be able to swing.
As an example of the swinging means for swinging the lower shaft unit 2, a configuration including a swing arm 25 and a servomotor 27 is employed in the present embodiment.
The swing arm 25 is a substantially fan-shaped member that is swingably supported by a rotation shaft (not shown) that passes through the point P and extends in a direction perpendicular to the paper surface. An oscillating gear 25a is formed on an arcuate end surface centered on the rotating shaft.
The servo motor 27 is provided with a pinion gear 26 engaged with the swing gear 25a of the swing arm 25 at the tip of the motor shaft, and rotates the pinion gear 26 so as to be able to rotate forward and backward.
The rotation of the servo motor 27 is controlled by a control unit 16 (see FIG. 2), which will be described later, electrically connected to each other.
An upper shaft unit 1 to which the workpiece 3 is detachably attached via the workpiece holder 4 is provided on the apparatus main body upper portion 20B so as to be movable up and down along an axis A that is a vertical axis passing through the point P.

  The mechanism for moving the upper shaft unit 1 up and down includes a slide guide 22 that extends in the vertical axis direction in the apparatus main body upper portion 20B, and a slider 23 that can be reciprocated on the slide guide 22 by a servo motor 24. . The upper shaft unit 1 is fixed on the slider 23 via the upper shaft spindle 12.

As shown in FIGS. 1 and 2, the upper shaft unit 1 includes a rotor 12a (first rotating shaft) including an upper shaft body 6 (first body) and an upper shaft chuck 10 (first chuck section) at the tip. Part), an upper shaft spindle 12 that rotatably supports the rotor 12a with the axis A as a rotation center axis, and an upper shaft motor 14 that rotationally drives the rotor 12a.
Here, the upper shaft assembly 6 and the upper shaft chuck 10 constitute a first holding means, and the upper shaft spindle 12 and the upper shaft motor 14 constitute a first rotating means.

The upper shaft body 6 is a shaft-like member provided coaxially with the shaft A, and includes a spherical core portion 6a that forms an attachment portion of the work holder 4 at the shaft tip portion, and the shaft base end portion is built in the rotor 12a. The upper shaft cylinder 7 is supported in a state in which it can be urged toward the shaft tip side (downward in the figure).
The mechanism for generating the pressing force is not particularly limited as long as the upper shaft cylinder 7 is a mechanism capable of urging the pressing force whose size is controlled in the axial direction. For example, an appropriate mechanism using a mechanical pressing force using a pressure spring or the like, electromagnetic force, fluid force, or the like can be employed. In the present embodiment, pneumatic type urging means that receives supply of compressed air from a pneumatic supply device (not shown) is employed.

In the present embodiment, the work 3 is a glass member for forming a concave flat lens having a concave lens surface having a lens diameter φD ₁ , a radius of curvature r, and a lens half angle θ ₁ as shown in FIG. The case where the concave lens surface is the polished surface 3a and the flat surface is the holding surface 3b will be described. Reference numeral 3c indicates a central axis of the workpiece 3 which is an optical axis of the lens.
The lens half angle θ ₁ is an angle formed by a straight line connecting the center of curvature O ₁ of the lens and the outer peripheral portion (outer peripheral portion) of the surface 3a to be polished and the central axis 3c, and is also referred to as “depth” of the lens. Is done.
As shown in FIG. 2, the work holder 4 includes a kanzashi receiving portion 4 a having a slightly larger concave spherical surface than the hemisphere in which the spherical core portion 6 a of the upper shaft kanshi 6 is rotatably fitted, and a concave spherical surface of the kanzashi receiving portion 4 a. A cylindrical held portion 4b extending coaxially with an axis passing through the center, and a concave workpiece holding portion holding the holding surface 3b of the workpiece 3 with a plane perpendicular to the central axis of the held portion 4b as a fixed surface 4c.
The workpiece 3 is fitted and held or bonded and held with respect to the workpiece holding portion 4c in a state where the central axis 3c of the workpiece 3 passes through the center of the Kanzashi receiving portion 4a.
The concave spherical surface of the Kanzashi receiving portion 4a is formed such that a portion below the hemisphere is formed on the inner side of the held portion 4b, and the other concave spherical portion is detachable from the axial end surface of the held portion 4b. Is formed by a retaining member (not shown) of the spherical core portion 6a provided on the workpiece holder 4, and the workpiece holder 4 can be exchanged with respect to the spherical core portion 6a by attaching and detaching the retaining member.
In the state where the retaining member is attached, the work holder 4 is supported by the spherical core portion 6a of the upper shaft body 6 so as not to be detached.

The upper shaft chuck 10 is a plurality of movable gripping members that can be switched between a state of gripping the outer peripheral side surface of the held portion 4b of the work holder 4 and a state of releasing the gripping. In the present embodiment, the rotor 12a A plurality of U-shaped arms extending from the side surface toward the work holder 4 are provided so as to open and close in the radial direction.
Although the opening / closing mechanism of the upper shaft chuck 10 is not particularly illustrated, for example, an electromagnetic opening / closing mechanism, a fluid opening / closing mechanism such as air pressure, and the like can be appropriately employed. The operation of these opening / closing mechanisms is controlled by the control unit 16.

According to such a configuration, when the held portion 4b of the work holder 4 is gripped by the upper chuck 10, the work 3 is aligned with the rotor 12a so that the center axis 3c is coaxially aligned with the axis A via the work holder 4. Fixed. In this fixed state, when the rotor 12a rotates, the workpiece 3 is coaxially rotated integrally with the rotor 12a.
Further, when the grip of the held portion 4b of the work holder 4 is released by the upper shaft chuck 10, the work holder 4 can be rotated with respect to the kanzashi receiving portion 4a, so that the tilt with respect to the axis A and the rotation around the axis A are performed. And can be tilted and rotated with respect to the upper shaft body 6. In this non-fixed state, even if the rotor 12 a rotates, the spherical core portion 6 a and the Kanzashi receiving portion 4 a slip, so that the rotational force of the rotor 12 a is not substantially transmitted to the work holder 4.

As shown in FIGS. 1 and 2, the lower shaft unit 2 includes a rotor 13 a (second rotating shaft) including a lower shaft body 8 (second body) and a lower shaft chuck 11 (second chuck portion) at the tip. Part), a lower shaft spindle 13 fixed to the swing arm 25 and rotatably supporting the rotor 13a about the axis B as a rotation center axis, and a lower shaft motor 15 for rotating the rotor 13a.
The axis B is set so as to pass through the point P and become the central axis of the swingable range of the swing arm 25.
Here, the lower shaft body 8 and the lower shaft chuck 11 constitute second holding means, and the lower shaft spindle 13 and the lower shaft motor 15 constitute second rotating means.

The lower shaft body 8 is a shaft-like member provided coaxially with the shaft B, and includes a spherical core portion 8a that forms a mounting portion of the polishing dish 5 at the shaft tip portion, and the shaft base end portion is built in the rotor 13a. The lower shaft cylinder 9 is supported so as to be urged toward the shaft tip side.
The lower shaft cylinder 9 employs the same configuration as the upper shaft cylinder 7.

The polishing dish 5 is for polishing the surface 3a to be polished by co-rubbing the workpiece 3, and has a configuration in which, for example, a polishing surface is formed by attaching an elastic material to a metal holding jig. That is, as shown in FIG. 4, the outer shape of the polishing dish 5 has a dish diameter φD ₂ (D ₂ > D ₁ ) and a radius of curvature r corresponding to the shape of the polished surface 3 a of the workpiece 3 on one surface. A convex spherical polishing surface 5d having a polishing dish half angle θ ₂ (θ ₂ > θ ₁ ) is formed of an appropriate elastic material, and on the back side thereof, a cylindrical covered surface coaxial with the central axis 5c of the polishing surface 5d. A holding portion 5b is formed.
Here, to the polisher half angle theta ₂ larger set than the lens half angle theta ₂ is the area of the polished surface 5d is set to be larger than the polished surface 3a, relatively reduce the wear of the polishing surface 5d Because. In the case of co-rubbing as performed in the polishing apparatus 100, the polished surface 5d is worn along with the polishing of the polished surface 3a, but the polished surface is reduced by reducing the wear of the polished surface 5d compared to the polished surface 3a. The shape accuracy of 3a can be further improved.
The end face of the held portion 5b, with the center of curvature O ₂ concentric with polished surface 5d, the hairpin receiving portion 5a having a slightly larger concave spherical than hemisphere rotatably fitted Tamashin portion 8a of the lower shaft hairpin 8 Is provided.
The concave spherical surface of the Kanzashi receiving portion 5a is detachable from the spherical core portion 8a in the same manner as the Kanzashi receiving portion 4a, and depends on the shape of the workpiece 3, the type of polishing process, the wear state of the polishing surface 5d, and the like. The polishing dish 5 can be changed as appropriate.
When the retaining member (not shown) for the spherical core portion 8a is attached, the polishing dish 5 is supported by the spherical core portion 8a of the lower shaft body 8 so as not to come off.

The lower shaft chuck 11 is a plurality of movable gripping members that can be switched between a state of gripping the outer peripheral side surface of the held portion 5b of the polishing dish 5 and a state of releasing the gripping. Similar to the chuck 10, a plurality of U-shaped arms extending from the side surface of the rotor 13a toward the polishing dish 5 are provided so as to open and close in the radial direction.
The opening / closing mechanism of the lower shaft chuck 11 is an opening / closing mechanism similar to that of the upper shaft chuck 10, and the opening / closing operation is controlled by the control unit 16.

According to such a configuration, when the held portion 5b of the polishing plate 5 is gripped by the lower shaft chuck 11, the polishing plate 5 is fixed to the rotor 13a with the center shaft 5c aligned with the axis B. In this fixed state, when the rotor 13a rotates, the polishing dish 5 is also coaxially rotated integrally with the rotor 13a.
Further, when the holding of the held portion 5b is released by the lower shaft chuck 11, since the polishing dish 5 is rotatable with respect to the Kanzashi receiving portion 5a, tilting with respect to the axis B and rotation around the axis B are possible. It is supported so as to be tiltable and rotatable with respect to the lower shaft body 8. In this non-fixed state, even if the rotor 13 a rotates, the spherical core portion 8 a and the Kanzashi receiving portion 6 a slip, so that the rotational force of the rotor 13 a is not substantially transmitted to the polishing dish 5.

The control unit 16 is electrically connected to the servo motors 24 and 27, the upper shaft motor 14, the upper shaft cylinder 7, the upper shaft chuck 10, the lower shaft motor 15, the lower shaft cylinder 9, and the lower shaft chuck 11, respectively. Each operation is controlled.
In this embodiment, the control unit 16 is composed of a computer and other hardware configured by a CPU, a memory, an input / output unit, an external storage device, and the like. Operation control is realized by running on a computer.

Next, a polishing operation using the polishing apparatus 100 will be described.
FIG. 5A is a schematic explanatory view showing the state of the polishing process in the first holding mode of the polishing apparatus according to the first embodiment of the present invention. FIG. 5B is a schematic explanatory view showing the state of the polishing process in the second holding mode of the polishing apparatus according to the first embodiment of the present invention. FIG. 6 is a schematic explanatory view showing a preferable positional relationship in the second holding mode of the polishing apparatus according to the first embodiment of the present invention.

The polishing apparatus 100 according to this embodiment includes two polishing modes, and the control unit 16 can switch the polishing modes as appropriate to repeat the polishing of the workpiece 3.
First, in the first polishing mode, as shown in FIG. 5A, the upper shaft chuck 10 is opened to bring the work holder 4 into an unfixed state, and the lower shaft chuck 11 is closed to hold the held portion 5b. Then, the first holding mode (first holding state) in which the polishing dish 5 is held in a fixed state is set. In this state, the slider 23 is moved so that the surface 3a to be polished of the workpiece 3 and the polishing surface 5d of the polishing dish 5 are brought into contact with each other.
At this time, by setting the rotation amount of the servo motor 27 suitably, an axis B which is the rotational center axis of the rotor 13a, to the axis A which is the rotation center axis of the rotor 12a, it is inclined by an angle phi _1.
In this state, the upper shaft body 6 is urged by the upper shaft cylinder 7 to press the surface to be polished 3a against the polishing surface 5d. As a result, in the cross section including the axis A, B, in contact with the polished surface 3a periphery of the polishing surface 5d is at point Q _1, the peripheral portion of the polished surface 3a is brought into contact with the polishing surface 5d at point S.

At this time, the angle ∠ SPQ ₁ expected by the arc SQ ₁ is expressed by the following equation.
∠SPQ ₁ = θ ₁ + θ ₂ −φ ₁ (1)
Further, the angle TPQ ₁ that the arc TQ _{1 of the} portion where the polishing surface 5d does not contact on the surface to be polished 3a is expressed by the following equation.
∠TPQ ₁ = θ ₁ −θ ₂ + φ ₁ (2)

Then, the lower shaft motor 15 is rotated and the rotor 13a is rotated in the direction of the arrow in the state where the polishing liquid is supplied continuously between the surface to be polished 3a and the polishing surface 5d by a polishing liquid supply mechanism (not shown). On the other hand, the rotation of the upper shaft motor 14 is stopped.
At the same time, the servo motor 27 is rotated forward and backward in a predetermined cycle to swing the swing arm 25 so that the axis B swings in the range of (φ ₁ ± Δφ ₁ ).
At this time, Δφ ₁ is set so that the polishing surface 5d always comes into contact with the surface to be polished 3a within the swing range of the axis B. That is, from the condition that Δφ ₁ ≧ ∠TPQ ₁ , the following equation is set.
Δφ ₁ ≧ θ ₁ −θ ₂ + φ ₁ (3)

By such an operation, the surface 3a to be polished is rocked and polished by the polishing surface 5d. At this time, since the workpiece 3 is rotatable about the axis A with respect to the upper shaft kanzashi 6, the workpiece 3 can be rotated in response to the rotational force transmitted from the polishing surface 5 d.
Therefore, the polishing processing force is generally governed by the processing force generated by the rotation of the polishing dish 5, and increases on the peripheral side of the polishing dish 5 having a high rotation speed. For example, the maximum in FIG. 5 points to _{Q 1} (a). The peripheral side of the polishing dish 5 having such a large processing force moves within a certain range of the surface 3a to be polished of the workpiece 3 by swinging. And since the workpiece | work 3 is tiltably supported by the spherical core part 6a, when the peripheral part of the grinding | polishing dish 5 moves to the peripheral part (for example, point T) of the workpiece 3, the opposing peripheral side (for example, point S) ), The workpiece 3 tilts in the clockwise direction in the figure and tends to escape from the polishing dish 5 at the point T. Therefore, in the vicinity of the point T, the machining force acting on the peripheral side of the workpiece 3 is reduced.

As a result, when the first polishing mode is continued, the polishing amount in the vicinity of the concentric circle passing through the point Q ₁ is relatively large, the polishing amount on the peripheral side of the workpiece 3 is relatively small, and the workpiece 3 is covered. The polished surface 3a is qualitatively polished with respect to the target spherical surface, for example, a surface having irregularities as shown in a conceptual diagram indicated by reference numeral 30 in FIG.
Therefore, in order to eliminate such irregularities, the polishing apparatus 100 can stop the polishing process after continuing the process in the first polishing mode for a predetermined time and perform the polishing process in the second polishing mode. ing.

In the second polishing mode, after processing in the first polishing mode, as shown in FIG. 5B, the lower shaft chuck 11 is opened to release the held portion 5b, and the polishing dish 5 is not fixed. In addition, the upper chuck 10 is closed, the held portion 4b is gripped, and the second holding mode (second holding state) in which the workpiece 3 is held in a fixed state is set.
At this time, by setting the rotation amount of the servo motor 27 suitably, an axis B which is the rotational center axis of the rotor 13a, to the axis A which is the rotation center axis of the rotor 12a, it is inclined by an angle phi _2.
In this state, the lower shaft body 8 is urged by the lower shaft cylinder 9, and the polishing surface 5d is pressed against the surface to be polished 3a. As a result, in the cross section including the axis A, B, in contact with the polished surface 3a periphery of the polishing surface 5d is at point Q _2, the peripheral portion of the polished surface 3a is brought into contact with the polishing surface 5d at point S.
At this time, the following equation holds as in the case of the first polishing mode.
∠SPQ ₂ = θ ₁ + θ ₂ −φ ₂ (4)
∠TPQ ₂ = θ ₁ −θ ₂ + φ ₂ (5)

Then, with the polishing liquid supply mechanism (not shown), the upper shaft motor 14 is rotated and the rotor 12a is rotated in the direction of the arrow in the state where the polishing liquid is continuously supplied between the polished surface 3a and the polishing surface 5d. On the other hand, the rotation of the lower shaft motor 15 is stopped.
At the same time, the servo motor 27 is rotated forward and backward at a predetermined cycle to swing the swing arm 25 so that the axis B swings in the range of (φ ₂ ± Δφ ₂ ).
At this time, Δφ ₂ is set so that the polishing surface 5d always comes into contact with the surface to be polished 3a within the swing range of the axis B. That is, from the condition that Δφ ₂ ≧ ∠TPQ ₂ , the following equation is set.
Δφ ₂ ≧ θ ₁ −θ ₂ + φ ₂ (6)

By such an operation, the surface 3a to be polished is rocked and polished by the polishing surface 5d. FIG. 5B shows a case where φ ₂ = φ ₁ so that the correspondence with the first polishing mode can be easily seen.
At this time, since the polishing dish 5 can rotate about the axis B with respect to the lower shaft body 8, it can rotate by receiving the rotational force transmitted from the surface to be polished 3a.
Therefore, the polishing processing force is generally governed by the processing force generated by the rotation of the workpiece 3 and increases on the peripheral side of the workpiece 3 having a large rotation speed. For example, it becomes maximum at the point S in FIG. The peripheral edge side of the workpiece 3 having such a large processing force moves within a certain range of the polishing surface 5d of the polishing plate 5 by relative swinging. And since it reciprocates in the vicinity of the axis B, even if the polishing dish 5 is supported by the spherical core portion 8a so as to be tiltable, the pressing force urged in the direction of the axis B via the lower shaft body 8 is reduced. There is not much. On the other hand, at the peripheral portion (for example, point Q ₂ ) where the rotational speed is relatively large and the polishing force from the polishing plate 5 is increased, the polishing plate 5 is tilted counterclockwise in the drawing and escapes. Processing force is reduced.

As described above, in the second holding mode, the holding relationship and the biasing state of the workpiece and the polishing dish are reversed with respect to the first holding mode, and the convex lens having the shape of the polishing dish 5 is assumed to be the workpiece 3 as a polishing dish. It is in a state of polishing.
Therefore, the distribution of polishing force becomes distributed as substantially reversing the distribution of the first polishing mode, continuing the second polishing mode, polishing amount in the vicinity of concentric circles passing through the point Q ₂ is relatively The polishing amount on the peripheral side of the work 3 is small and the polishing surface 3a of the work 3 is qualitatively compared to the target spherical surface, for example, reference numeral 31 in FIG. Polished to a surface having irregularities as shown in the conceptual diagram.

  Therefore, the amount of polishing with respect to the surface to be polished 3a is balanced by performing the second polishing mode following the first polishing mode or by performing polishing while switching between these modes. And the polishing accuracy of the surface to be polished 3a can be improved.

Note that the angle φ ₂ of the second holding mode is not necessarily the same as the angle φ ₁ of the first holding mode.
The polishing force is governed by the polishing dish 5 side in the first polishing mode and by the workpiece 3 side in the second polishing mode. Therefore, in the first polishing mode, it is preferable in terms of processing efficiency that the angle φ ₁ is set so that the peripheral edge of the polishing dish 5 moves on the surface to be polished 3a in the widest possible range. In the second polishing mode, as the peripheral portion of the workpiece 3 as much as possible contact on the polishing surface 5d, setting the angle phi ₂ is the working efficiency preferably.
Therefore, [Delta] [phi ₁ determines the oscillation _range, depending on the setting of the [Delta] [phi _2, the first holding mode, as shown in FIG. 5 (a), the point to Q ₁ periphery of the polishing dish 5, a work The angle φ ₁ is preferably set so as to be located between the point T of the peripheral edge 3 and the center U of the surface 3a to be polished. In the second holding mode, as shown in FIG. ₂ is preferably set so that the angle φ ₂ is positioned closer to the point T than the first holding mode. That is, it is preferable to set the relationship such that φ ₁ > φ ₂ .
The angle φ ₁ is more preferably set so that the point Q ₁ is located approximately in the middle between the point T and the center U, and the angle φ ₂ is set so that the point Q ₂ is substantially coincident with the point T. More preferably.

[Second Embodiment]
A polishing apparatus according to a second embodiment of the present invention will be described.
FIG. 7 is a schematic front view showing the main part of the polishing apparatus according to the second embodiment of the present invention. FIGS. 8A and 8B are partially enlarged views of C view and D view of FIG. 7, respectively.

As shown in FIGS. 1 and 7, the polishing apparatus 110 according to the present embodiment includes a work holder 4 </ b> A and a polishing dish 5 </ b> A in place of the work holder 4 and the polishing dish 5, respectively, in the polishing apparatus 100 according to the first embodiment. In addition, a slide pin 17 (first locking means) and a slide pin 18 (second locking means) are provided for the upper shaft body 6 and the lower shaft body body 8, respectively. FIG. 7 illustrates the holding state in the second holding mode.
Hereinafter, a description will be given centering on differences from the first embodiment.

As shown in FIGS. 7 and 8 (a), the work holder 4A is formed by extending the held portion 4b of the work holder 4 in a cylindrical shape toward the rotor 12a, and on the outer peripheral side surface of the cylindrical held portion 4b. A slide groove 4d made of a parallel groove or a U-shaped groove extending in the direction of the central axis of the cylinder is formed.
The slide pin 17 of the upper shaft body 6 is configured to extend in the radial direction on the side surface of the upper shaft body 6 and to be slidably fitted in the slide groove 4d of the work holder 4A in the axial direction.

As shown in FIGS. 7 and 8B, the polishing dish 5A is formed by extending the held portion 5b of the polishing dish 5 in a cylindrical shape toward the rotor 13a, and the inner peripheral surface of the cylindrical held portion 5b. On the side, a slide groove 5e made of a concave parallel groove or a U-shaped groove extending in the direction of the central axis of the cylinder is formed.
The slide pin 18 of the lower shaft body 8 is configured to extend radially on the side surface of the lower shaft body 8 and engage with the slide groove 5e of the polishing dish 5A so as to be slidable in the axial direction.

According to such a polishing apparatus 100A, the work holder 4A and the upper shaft body 6, and the polishing plate 5A and the lower shaft body 8 are engaged around the axes A and B by the slide pins 17 and 18, respectively. Further, as the slide pins 17 and 18 slide in the axial direction in the slide grooves 4d and 5e, a plane including the groove width center line of the slide groove 4d and the axis A, and a groove width center line of the slide groove 5e, respectively. On the plane including the axis B, the work holder 4A and the polishing dish 5A are each held so as to be tiltable.
That is, in this embodiment, the upper shaft chuck 10 and the lower shaft chuck 11 are held in a state in which only tilting is possible when the work holder 4A and the polishing dish 5A are set in an unfixed state, respectively. is there.

In this embodiment, in the first and second polishing modes, the lower shaft motor 15 and the upper shaft motor 14 in the non-fixed state are rotated together with the upper shaft motor 14 and the lower shaft motor 15 in the fixed state. That is, in the first holding mode, the work holder 4A can rotate synchronously with the rotor 12a about the axis A. Further, in the second holding mode, the polishing dish 5A can rotate synchronously with the rotor 13a around the axis B.
For this reason, in the first and second polishing modes, the polishing process is performed in a state where the relative rotation of the surface to be polished 3a and the polishing surface 5d around the axes A and B is synchronized with the rotation of the rotors 12a and 13a. Can do.
For example, in the polishing apparatus 100 according to the first embodiment, when the lens half angle θ ₁ of the workpiece 3 is significantly smaller than the polishing dish half angle θ ₂ of the polishing dish 5A, the contact area is small, and thus the fixed state is established. In some cases, the rotational force of rotation is not sufficiently transmitted from the rotated side to the non-fixed side. In this case, since the surface to be polished 3a and the polishing surface 5d are moving relative to each other, the polishing proceeds but the polishing efficiency is inferior. Further, since the polishing surface 5d does not rotate around the axis B, uneven wear tends to occur on the polishing surface 5d.
According to the present embodiment, since the workpiece 3 and the polishing dish 5 can be rotated about the axis A or the axis B even in the non-fixed state, the lens half angle θ ₁ of the workpiece 3 is the polishing dish half angle θ ₂ of the polishing dish 5A. Even when it is significantly smaller than the above, the progress of polishing can be stabilized and the accuracy of the polished surface can be improved.

In the above description, the example in which the workpiece 3 is a single lens has been described. However, a plurality of workpieces may be processed at the same time using a bonding jig for arranging a plurality of workpieces as the workpiece holder 4. .
FIG. 9 is a schematic cross-sectional view showing an example of a sticking jig when a plurality of workpieces are processed in the polishing apparatus according to the first and second embodiments of the present invention.

As shown in FIG. 9, the affixing jig 19 has a held portion 19b that can be held in the same manner as the single workpiece 3 with respect to the concave workpiece holding portion 4c, and the facing surface side of the held portion 19b. Further, an attaching portion 19a for attaching a plurality of workpieces 3A is formed. Then, the work 3A is attached to each attaching portion 19a so that each surface to be polished 3a is aligned on a spherical surface having a radius r.
A plurality of workpieces 3 </ b> A can be simultaneously polished by attaching the attaching jig 19 to the workpiece holder 4 of the first and second embodiments instead of the workpiece 3.

  In the above description, the swinging means is described as an example in which the polishing dish side is swung. It may be provided and swung.

  In the above description of the second embodiment, the first and second holding means are provided with the first and second locking means, respectively. However, either one is required as necessary. It is good also as a structure which provided the latching means.

  In the above description, the example in which the first and second holding means are used as the first and second holding means has been described. If there is, it is not limited to such a configuration. For example, the structure which implement | achieves a fixed state may be sufficient by a to-be-held part and a holding means fitting a recessed part and a convex part.

1 is a schematic front view showing a schematic configuration of a polishing apparatus according to a first embodiment of the present invention. It is a typical front view showing the principal part of the polish device concerning a 1st embodiment of the present invention. It is sectional drawing which shows an example of the workpiece | work of the grinding | polishing apparatus which concerns on the 1st Embodiment of this invention. It is a fragmentary sectional view showing an example of a polish plate of a polish device concerning a 1st embodiment of the present invention. It is a schematic explanatory drawing which shows the mode of the grinding | polishing process in the 1st and 2nd holding | maintenance modes of the grinding | polishing apparatus which concerns on the 1st Embodiment of this invention. It is a schematic explanatory view showing a preferred positional relationship in the second holding mode of the polishing apparatus according to the first embodiment of the present invention. It is a typical front view which shows the principal part of the grinding | polishing apparatus which concerns on the 2nd Embodiment of this invention. It is the elements on larger scale of C view and D view of FIG. In the polish device concerning the 1st and 2nd embodiment of the present invention, it is a typical sectional view showing an example of a pasting jig in the case of processing a plurality of works.

Explanation of symbols

100, 100A Polishing apparatus 3, 3A Workpiece 3a Polished surface 4, 4A Work holder 4a Kanzashi receiving part 4b Holding part 4c Work holding part 4d, 5e Slide groove 5, 5A Polishing dish 5a Kanzashi receiving part 5b Holding part 5d Polishing Surface 6 Upper shaft Kanzashi (first Kanzashi)
6a Sphere core part 7 Upper shaft cylinder 8 Lower shaft Kanzashi (second Kanzashi)
9 Lower shaft cylinder 10 Upper shaft chuck (first chuck)
11 Lower shaft chuck (second chuck)
12 Upper spindle (first rotating means)
12a Rotor (first rotating shaft)
13 Lower shaft spindle (second rotating means)
13a Rotor (second rotating shaft)
14 Upper shaft motor (first rotating means)
15 Lower shaft motor (second rotating means)
16 Control unit 17 Slide pin (first locking means)
18 Slide pin (second locking means)
20 Device body 25 Swing arm 25a Swing gear 27 Servo motor

Claims (7)

A polishing apparatus that polishes the workpiece by moving the polishing plate and the workpiece relative to each other by pressing a polishing plate having a convex or concave spherical polishing surface and a surface to be polished of the workpiece in contact with each other. There,
First rotating means having a first rotating shaft for rotating the workpiece;
A fixed state provided on the first rotating shaft portion and fixing the work to the first rotating shaft portion, and supporting the work so as to be tiltable with respect to a rotation center axis of the first rotating shaft portion. First holding means that can be switched to an unfixed state,
Second rotating means having a second rotating shaft for rotating the polishing dish;
A fixed state that is provided on the second rotation shaft portion and fixes the polishing dish to the second rotation shaft portion, and the polishing dish can be tilted with respect to the rotation center axis of the second rotation shaft portion. Second holding means switchable to an unfixed state supported by
Rocking means for holding the first and second rotating means so as to be relatively rockable about the center of curvature of the polishing surface;
A first holding mode in which the first holding means is in a non-fixed state of the first holding means, and the second holding means is in a fixed state of the second holding means; Control means for performing polishing by switching between a second holding mode in which the holding means is in the fixed state of the first holding means and the second holding means is in the non-fixed state of the second holding means. A polishing apparatus comprising:   2. The polishing apparatus according to claim 1, wherein the workpiece is held so as to be rotatable around a rotation center axis of the first rotation shaft portion in a non-fixed state of the first holding means.   3. The polishing apparatus according to claim 1, wherein the polishing dish is held rotatably around a rotation center axis of the second rotation shaft portion in a non-fixed state of the second holding means.   The polishing apparatus according to claim 1, wherein the first holding unit includes a first locking unit that locks the workpiece with respect to a rotation direction of the first rotating shaft portion.   The said 2nd holding means was equipped with the 2nd latching means which latches the said polishing dish with respect to the rotation direction of a said 2nd rotating shaft part, The Claim 1 or 4 characterized by the above-mentioned. Polishing equipment. The first holding means includes
Provided coaxially with the first rotating shaft portion, press the workpiece from the back side of the surface to be polished, and support the workpiece so as to be rotatable and tiltable with respect to the rotation center axis of the first rotating shaft portion. With the first Kanzashi,
The polishing apparatus according to claim 1, further comprising: a first chuck portion that fixes the workpiece to the first rotating shaft portion. The second holding means is
Provided coaxially with the second rotation shaft portion, press the polishing dish from the back surface side of the polishing surface, and support the rotation plate so as to be rotatable and tiltable with respect to the rotation center axis of the second rotation shaft portion. The second Kanzashi,
The polishing apparatus according to claim 1, further comprising a second chuck portion that fixes the polishing dish to the second rotating shaft portion.

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