JPH09323252A - Profile polishing method and device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve in the accuracy of finishing as well as to aim at the promotion of a decrease in cost. SOLUTION: A pressing direction of an abrasive tool 52 is accorded with the normal of a work surface 34A through this nearly spherical abrasive tool 52 while a turning shaft 51A of this abrasive tool 52 is scanned on the work surface 34A as maintaining a specified angle to the normal of this work surface 34A and thereby polishing work is made so as to be done. Successively, in time of polishing, at least a rotational speed in the abrasive tool 52, or pressing force of this abrasive tool is made so as to be controlled according to a polishing position of the abrasive tool 52.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is intended for polishing optical elements such as lenses and mirrors having a curved surface, in particular, an aspherical shape having no axis of rotational symmetry, and a molding die for injection molding these. Regarding a curved surface polishing method and a curved surface polishing apparatus,
In particular, the present invention relates to a curved surface polishing method and a curved surface polishing apparatus that improve the processing accuracy and reduce the cost.

[0002]

2. Description of the Related Art A conventional curved surface polishing apparatus for polishing optical elements such as lenses and mirrors having a curved surface shape, particularly an aspherical shape having no axis of rotational symmetry, and a molding die for injection molding these. For example, there is one disclosed in JP-A-5-57606.

FIG. 8 shows the curved surface polishing apparatus. This curved surface polishing apparatus measures a horizontal drive unit 1A that causes a workpiece 3 to perform a predetermined horizontal motion on a surface plate 2, and a surface shape of a processed surface 3A of the workpiece 3 that has been moved by the horizontal drive unit 1A. The shape measuring unit 1B and a polishing processing unit for performing a polishing process on the processing surface 3A of the workpiece 3 moved by the horizontal driving unit 1A based on the surface shape data of the processing surface 3A obtained by the measurement of the shape measuring unit 1B. 1C.

[0004] The horizontal drive unit 1A is provided on a surface plate 2 so as to be movable in the Y-axis direction, and is disposed along the Y-axis direction. A nut (not shown) of the Y-axis table 4 is provided. The ball screw 5 screwed with the
A motor 6 for moving the axis table 4 in the Y-axis direction, an X-axis table 7 movably provided in the X-axis direction on the Y-axis table 4, and an X-axis table 7 A ball screw 8 screwed to a nut (not shown), a motor 9 for rotating the ball screw 8 to move the X-axis table 7 in the X-axis direction, and arranged on the X-axis table 7 and rotated by a motor (not shown) It has a θ table 10.

[0005] The polishing portion 1C is provided with an L
V-shaped polishing frames 11A, 11B and 11C, a Z tilting device 13 attached to the tips of the polishing frames 11A, 11B and 11C via a mounting plate 12, and a polishing head attached to the bottom of the Z tilting device 13. 1
Four.

FIG. 9 shows the structure of the Z tilting device 13. The Z tilting device 13 includes a triangular mounting plate 1 in which three corners 15a are fixed to the mounting plate 12, respectively.
5, shafts 16A to 16C (16C not shown) fixed parallel to each side on the triangular mounting plate 15;
A pair of inner portions extending in the Z-axis direction are slidably engaged with a pair of side portions extending in the Z-axis direction of the blocks 17A to 17C rotatably attached to the blocks A to 16C, respectively. The polishing arms 18A to 18C each having a rectangular shape, each extending in the Z-axis direction, being supported by the polishing arms 18A to 18C,
Ball screws 19A to 19C screwed into nuts (not shown) of 7A to 17C, motors 20A to 20C for rotating the ball screws 19A to 19C to move the polishing arms 18A to 18C in the Z-axis direction, and the polishing arms 18A to 18C. 18C
Has a triangular polishing head attachment plate 22 attached to the lower end of the head via universal joints 21A to 21C.

FIG. 10 shows the configuration of the polishing head 14. The polishing head 14 applies a pressing force to the polishing tool 23 via a load shaft 25, a cylindrical polishing tool 23 that polishes the processed surface 3A of the workpiece 3, a polishing tool holding device 24 that holds the polishing tool 23, and a load shaft 25. And a rocking device 27 that reciprocates the polishing tool 23 in the direction of arrow D.

The constant pressure device 26 is constructed so as to always maintain a pressing force set by a voice coil motor attached to the load shaft 25, a leaf spring, and a load sensor (none of which is shown). A displacement sensor (not shown) that detects the amount of axial displacement of the load shaft 25 is attached to the load shaft 25.

The oscillating device 27 includes a rotating shaft 28 of a motor 28.
A, a connecting rod 30 for converting the rotational motion of the crank 29 into a reciprocating motion, a constant pressure device 2
6 and has a slider 32 that slides on a slide shaft 31 by inputting a reciprocating motion from a connecting rod 30.

In the above-described configuration, when the workpiece 3 is polished, first, an abrasive is applied to the processing surface 3A of the workpiece 3, and the polishing head 13 is lowered by the Z tilting device 14 to polish the workpiece. The tool 23 is brought into contact with the processing surface 3A. Next, the rocking device 27 reciprocates the polishing tool 23 in the direction of the arrow D, and a constant pressure device 26 applies a predetermined pressing force to the polishing tool 23 to polish the polishing surface of the polishing tool 23 and the processed surface 3A of the workpiece 3. Use and to rub. At this time, the scanning pattern, and the pressing direction of the polishing tool 23 and the normal direction of the processing surface 3A always match, and the displacement amount of the load shaft 25 measured by the displacement sensor becomes constant. The Y-axis table 4, the X-axis table 7, the θ table 10, and the Z tilting device 14 are synchronously controlled in accordance with a scanning velocity distribution described later, whereby the polishing head 13 performs scanning in accordance with the shape of the processing surface 3A to perform processing. Surface 3
A polishing is performed. Here, the polishing amount is determined by the polishing tool 23.
Proportional to the pressing force of, the relative speed with the work piece, the residence time,
The residence time distribution for bringing the shape of the processing surface 3A closer to the target surface shape, that is, the scanning speed distribution of the polishing tool 23 is determined by the polishing tool 23 when the pressing force and relative speed of the polishing tool 23 are kept constant. It is obtained from the unit removal shape for removing 3A per unit time, and the difference between the shape of the processed surface 3A measured by the shape measuring unit 1B and the target surface shape.

[0011]

However, the conventional curved surface polishing apparatus has the following problems. (1) Since the polishing tool has a columnar shape, the contact area with the processing surface is large, and if the curvature of the processing surface with which the polishing tool contacts changes as the polishing head scans, the pressing force of the polishing tool is kept constant. However, the pressing force distribution under the polishing tool will change. Also, at a position where the approximate radius of curvature is small, the direction of the normal to the processing surface with which the polishing tool contacts changes significantly with the scanning of the polishing head, and the contact point of the polishing tool changes, and the relative velocity distribution and pressing under the polishing tool The force distribution changes. Therefore, the unit removal shape, which is the product of the pressing force, the relative speed, and the residence time, changes depending on the position, and the processing accuracy decreases. (2) Since the scanning of the polishing head is performed by the 6-axis driving mechanism, the structure is complicated and the cost is increased. (3) Since the polishing head scans according to the shape of the processed surface, a large number of control data are required for the drive control of the polishing head at a short scanning distance, and the scanning speed of the polishing head is increased due to the increase in calculation time. It will be late. Therefore, the scanning speed of the polishing head cannot be controlled to adjust the polishing amount, and the processing accuracy is reduced. (4) Since the scanning of the polishing head is controlled by synchronously controlling each drive axis over the entire surface to be machined, the amount of control data becomes enormous and the cost increases due to an increase in the memory capacity of the drive control unit.

Therefore, the object of the present invention is to improve the machining accuracy,
Another object of the present invention is to provide a curved surface polishing method and a curved surface polishing apparatus that can reduce the cost.

[0013]

In view of the above problems, the present invention prepares a substantially spherical polishing tool having elasticity and changes it depending on the surface shape in order to improve the processing accuracy and reduce the cost. Match the normal of the work surface of the work with the pressing direction of the polishing tool, press the polishing tool against the work surface with a predetermined pressing force, rotate the polishing tool around a predetermined rotation axis, and The present invention provides a curved surface polishing method for polishing a machined surface by scanning the machined surface with the abrasive tool while maintaining the angle between the machine tool and a predetermined rotation axis of the machine tool at a predetermined angle.

The polishing tool is preferably prepared by providing a polisher on the surface of a substantially spherical elastic body having a diameter of 50 mm or less and an elastic modulus of 1 kgf / mm ² or less.

The polishing tool is preferably prepared by supplying a fluid to a bag-shaped member made of an elastic material having a polisher on its surface to expand it into a spherical shape having a predetermined size.

The matching of the pressing direction of the polishing tool with respect to the normal line and the maintenance of the predetermined angle of the predetermined rotation axis of the polishing tool with respect to the normal line are orthogonal to each other on the horizontal plane with respect to the polishing tool held in the predetermined posture. It is desirable to do this by rotating the workpiece about two axes.

The polishing of the processed surface preferably includes rough polishing performed by setting a predetermined angle to an angle greater than 0 and finish polishing performed by setting a predetermined angle to 0.

It is desirable that the above-mentioned workpiece has a toy which is a portion to be discarded around the processed surface, and the polishing of the processed surface is preferably performed according to a plurality of scanning patterns divided on the toy.

Further, in the above-mentioned curved surface polishing method, at the time of polishing the processed surface, at least one of the rotation speed of the polishing tool and the pressing force of the polishing tool may be controlled according to the scanning position of the polishing tool.

Further, the present invention achieves the above object,
A substantially spherical polishing tool having elasticity, a pressing means for pressing the polishing tool against a processing surface of a workpiece in a predetermined pressing direction with a predetermined pressing force, and a rotating means for rotating the polishing tool on a predetermined rotation axis. , Horizontal displacement means for displacing the relative position of the work piece and the polishing tool in the horizontal direction, and changing the relative angle between the normal line of the work surface of the work piece, the predetermined rotation axis of the polishing tool, and the predetermined pressing direction Controlling the angle changing means and the horizontal displacing means to cause the polishing tool to scan the processing surface, and controlling the angle changing means to match the normal line with the pressing direction of the polishing tool, and A curved surface polishing apparatus provided with a control means for polishing a machined surface while maintaining an angle with a predetermined rotation axis of a polishing tool at a predetermined angle.

It is desirable that the polishing tool comprises a substantially spherical elastic body having a diameter of 50 mm or less and an elastic modulus of 1 kgf / mm ² or less, and a polisher provided on the surface thereof.

The polishing tool has a bag-shaped member made of an elastic material and a polisher provided on the surface of the bag-shaped member, and supplies a fluid to the bag-shaped member to form a substantially spherical shape of a predetermined size. It is desirable that it is inflated.

The angle changing means is preferably constituted by a work piece rotating means for rotating the work piece about two axes orthogonal to each other on a horizontal plane.

It is preferable that the rotating means has a structure in which the predetermined angle is set to an angle larger than 0 in the rough polishing step, and the predetermined angle is set to 0 in the finish polishing step.

The work piece has a tool to be a part to be discarded around the work surface, and the control means causes the work surface of the polishing tool to be polished in accordance with a plurality of scanning patterns divided on the tool. Is desirable.

The pressing means preferably has a pressing force applying means for applying a predetermined pressing force regardless of the vertical position of the polishing tool.

It is desirable that the pressing force applying means is a weight balance mechanism that generates a predetermined pressing force based on the difference between the weight of the polishing tool and the weight of the support that supports the polishing tool.

It is desirable that the pressing force applying means is a cylinder mechanism that generates an internal pressure according to the reaction force that the polishing tool receives from the processing surface.

Further, in the above curved surface polishing apparatus, the control means controls at least one of the rotation speed of the polishing tool or the pressing force of the polishing tool according to the scanning position of the polishing tool when polishing the work surface. May be. In that case, it is desirable that the pressing force applying means is a cylinder mechanism that generates an internal pressure according to the reaction force that the polishing tool receives from the processing surface.

[0030]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a curved surface polishing method and a curved surface polishing apparatus according to the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 shows the structure of a curved surface polishing apparatus according to the first embodiment of the present invention. This curved surface polishing apparatus is provided on a support surface plate 33, and has a table drive drive unit 35 for causing the work piece 34 to perform a predetermined motion, and the work piece 3.
No. 4, which is located on the processing surface 34A, and which polishes the processing surface 34A, supports the polishing head 36 at an arbitrary position in the X-axis direction, and holds the surface 34 to be processed.
A support mechanism section 37 for vertically moving the polishing head 36 according to the shape of A, and a drive control section 3 for synchronously controlling each drive mechanism section.
It is configured with 3A.

The table mechanism portion 35 is provided on the Y-axis mechanism portion 38 for causing the workpiece 34 to horizontally move in the Y-axis direction, and the table mechanism portion 35 has an axis parallel to the X-axis for the workpiece 34. An α-axis mechanism unit 39 that performs rotational movement in a circular arc direction (hereinafter, referred to as an α-axis direction) and an α-axis mechanism unit 51 that are provided on the workpiece 34 with an axis parallel to the Y-axis as the center. It is configured to have a β-axis mechanism portion 40 that performs a rotational motion in an arc direction (hereinafter, β-axis direction), and a fixing jig 41 that positions and fixes the workpiece 34 on the β-axis mechanism portion 40.

The Y-axis mechanism section 38 includes two parallel guides 42A and 4A arranged on the support surface plate 33 and extending in the Y-axis direction.
2B, a Y-axis table 43 slidably engaged with the guides 42A and 42B, and a ball screw that is arranged in parallel between the guides 42A and 42B and is screwed with a nut (a screw shown in the drawing) provided on the Y-axis table 43. 44, and one end of a ball screw 44 connected to the output shaft, and a servo motor 45 for rotating the ball screw 44 to move the Y-axis table 43 in the Y-axis direction and stopping and positioning the Y-axis table 43 at a predetermined position. There is.

The α-axis mechanism section 39 is provided on the Y-axis table 43, and has an arc guide 46 having a concave arc surface 46A whose center of curvature is an axis parallel to the X axis, and an axis parallel to the X axis. A convex convex arc surface 47A with the center of curvature as the center of curvature is formed, and the α-axis table 47 engaged with the arc guide 46 so as to be rotatable in the α-axis direction and the nut (provided on the α-axis table 47 ( A ball screw (not shown) screwed together with one end of the ball screw is connected to the output shaft, the ball screw is rotated to rotate the α-axis table 47 in the Y-axis direction, and at a predetermined position. It is composed of a servo motor (not shown) for stopping and positioning.

The β-axis mechanism section 40 is provided on the α-axis table 47, and has an arc guide 48 having a concave arc surface 48A whose center of curvature is an axis parallel to the Y axis, and an axis parallel to the Y axis. A convex arc surface 49A having a center of curvature is formed, and a β-axis table 49 engaged with the arc guide 48 so as to be rotatable in the α-axis direction and a nut (not shown) provided on the β-axis table 49. ) Ball screw (not shown)
And one end of a ball screw is connected to the output shaft, the ball screw is rotated to rotate the β-axis table 49 in the X-axis direction,
In addition, it is composed of a servo motor 50 that stops and positions at a predetermined position.

The polishing head 37 is attached to the spindle 51 that generates a rotational torque by being driven by a driver (not shown) and the tip of the rotary shaft 51A of the spindle 51. It is composed of a polishing tool 52 for polishing 34A.

The support mechanism portion 37 includes an X-axis mechanism portion 53 that causes the polishing head 37 to move horizontally in the X-axis direction and a vertical mechanism portion 54 that moves the polishing head 36 up and down according to the shape of the surface 34A to be processed. It is equipped with.

The X-axis mechanism section 53 includes columns 55A and 55B provided on the support surface plate 33, and guides 56 supported by the columns 55A and 55B so as to be arranged along the X-axis direction.
An X-axis slider 57 slidably engaged with the guide 56, a ball screw (not shown) screwed with a nut (not shown) provided on the X-axis slider 57, and one end of the ball screw on the output shaft. Connected and rotate the ball screw X
A servo motor (not shown) that moves the shaft slider 55 in the X-axis direction and stops at a predetermined position for positioning.
Is configured.

The vertical mechanism 54 has a slider 58A to which the spindle 51 is fixed and which can move up and down.
6 is slid on a slide mechanism portion 58 that holds the polishing head 36 in a fixed posture by guiding the up and down movement of the polishing head 36, and pulleys 59A and 59B. A slider 58A is provided at one end and a weight 60 is provided at the other end.
Are connected to the wire 61. The weight of the weight 58 is smaller than the total weight of the slider 58A, the spindle 51, and the polishing tool 52 by a predetermined weight, and when the polishing tool 52 descends according to the shape of the processing surface 34A, the weight 58 depends on its displacement amount. When the weight 60 rises by a certain distance and the polishing tool 52 rises in accordance with the shape of the processing surface 34A, the weight 59 lowers by a distance corresponding to the amount of displacement of the weight 60 and the polishing tool 52 slides. 58A, spindle 51, and polishing tool 52
The force of the weight 60 minus the force of the weight 60 is pressed against the polishing surface 34A.

The drive control unit 33A has a Y-axis mechanism unit 38, which is a horizontal drive shaft, an X-axis mechanism unit 53, and an α-axis mechanism unit, which is a tilt drive shaft, based on drive data calculated by a drive calculation unit (not shown). 39 and β-axis mechanism unit 40 in total 4
The drive of the shaft is synchronously controlled so that the polishing head 36 moves the machining surface 34
In order to always maintain a constant posture with respect to A, that is, the pressing direction of the polishing tool 52 matches the normal line of the processing surface 34A,
Further, the polishing tool 52 is caused to scan so that the rotary shaft 51A maintains a predetermined angle with respect to the normal line of the processing surface 34A.

Here, the drive control of the horizontal drive shaft and the tilt drive shaft will be described.

FIG. 2 shows the work surface 3 with which the polishing tool 52 contacts.
4 shows a scanning pattern L when the position of 4A is moved based on a predetermined scanning speed. The scanning pattern L is formed by repeating a scanning line extending in a predetermined direction and a scanning line changing in a direction orthogonal to the predetermined direction and then extending in a direction opposite to the predetermined direction. The drive calculation unit scan pattern L
The angle data of the tilt drive unit for leveling the tilt of the machining surface 34A at the above points P ₁ , P ₂ , ...
The position data of the horizontal drive unit for matching the positions of ₁ , P ₂ , ..., With the position where the polishing tool 52 contacts, and the speed for moving between the points P ₁ , P ₂ ,. Calculate the data. The drive control unit 33A, based on the drive data (angle data, position data, and speed data) calculated by the drive calculation unit, the Y-axis mechanism unit 38, the X-axis mechanism unit 53, the α-axis mechanism unit 39, and the β-axis. Synchronous control of driving of a total of four axes of the mechanical unit 40 is performed.

FIG. 3 shows a sectional structure of the polishing head 36. The spindle 51 is fixed by a servo motor 62 whose rotational speed is controlled by a driver (not shown), a rotary shaft 51A connected to the output shaft of the servo motor 62 via a coupling 63, and housings 64A and 64B. Bearing 65 supporting 51A
It is composed of A and 65B. On the other hand, the polishing tool 52
Is detachably attached to the rotary shaft 51A via a fixing pin 66 so that the center of rotation is the same as that of the rotary shaft 51A, and the tool shaft center 67 and the tool shaft 67 are exchanged according to the material and size of the workpiece 34. A spherical body having a diameter of 50 mm or less is formed around the spherical portion 67A at the tip of the shaft 67, and an elastic body 68 made of a soft material having an elastic modulus of 1 kgf / mm ² or less such as silicone rubber is formed on the surface of the elastic body 68. The polishing machine 69 is configured by a polisher 69 that holds an abrasive and performs polishing.

A curved surface polishing method using the curved surface polishing apparatus will be described below.

First, an abrasive is applied to the processed surface 34A of the workpiece 34, and the load of the weight 60 is adjusted to adjust the polishing tool 5
2 is pressed against the processed surface 34A with a small force. And
The motor 62 of the spindle 51 is driven to rotate the polishing tool 52 to polish the processing surface 34A of the workpiece 34. At the same time, the drive control unit 33A causes the servo motor 45, based on the drive data previously calculated by the drive calculation unit.
A predetermined control signal is output to each driver of the servo motor of the X-axis mechanism unit 53, the servo motor of the α-axis mechanism unit 39, and the servo motor 50 to set the horizontal position of the Y-axis table 43 and the X-axis slider 57. By controlling the rotational positions of the α-axis table 47 and the β-axis table 49, the polishing head 36 always faces a fixed direction with respect to the processing surface 34A, that is, the pressing direction of the polishing tool 52 is the processing surface 34.
It coincides with the normal line of A, and the rotary shaft 51A has a processed surface 34A.
Polishing tool 5 to maintain a predetermined angle with respect to the normal
The machining surface 34A is scanned at 2. At this time, the polishing tool 52 is moved by the points P ₁ , P ₂ , ... Of the scanning pattern L.
Although the height at which is pressed varies, the slide mechanism 58
Since the polishing tool 52 moves up and down according to the height of the slider 58A when the slider 58A moves up and down,
The polishing process can be performed with a constant pressing force obtained by subtracting the force due to the load of the weight 59 from the force due to the total weight of the spindle 51 and the polishing tool 52.

As described above, in the first embodiment, the polishing tool 52 having a substantially spherical shape and elasticity is
The pressing direction coincides with the normal line of the processed surface 34A, and
The rotating shaft 51A is scanned and polished so as to maintain a predetermined angle with respect to the normal line of the processing surface 34A. In such a polishing method, even if the curvature of the processing surface 34A changes due to the scanning of the polishing tool, the portion of the polishing tool 52 other than the contact portion with the processing surface 34A is hard to contact the processing surface 34A, and does not contact the processing surface 34A. However, since the elastic body 68 absorbs the shape change of the processing surface 34A, the contact area of the polishing tool 52 and the distribution of the pressing force can be kept constant. Further, even when the curvature of the machined surface 34A is different depending on the direction, the pressing force distribution can be kept uniform for the same reason.

4 (a) and 4 (b) show the results of measuring the relationship between the average polishing depth and the change in the curvature of the machined surface, and (a) shows the diameter 1
The result when polishing was performed using a 0 mm cylindrical polishing tool, and (b) shows the result when polishing was performed using a spherical polishing tool having a diameter of 40 mm. The measurement conditions were as follows: the pressing force of the polishing tool was 2N, the rotation speed of the polishing tool was 600 rpm, and the moving speed of the polishing tool was 200 mm /
min and the scanning pattern pitch are unified to 0.2 mm. The machined surface is a cylindrical machined surface having different curvatures, and each machined surface is measured. The axis of rotation of the polishing tool is always aligned with the normal to the machined surface, and the number of machining is 0 m-1
The average polishing depth at the time of (planar) is adjusted to be 3 μm. As can be seen from this result, in (a), when the curvature of the machined surface changes, the average polishing depth also changes and uniform polishing depth cannot be obtained, but in (b), it is almost constant regardless of the curvature of the machined surface. The average polishing depth is obtained. As a result, it can be seen that even a workpiece having an aspherical shape without a rotational symmetry axis can be kept constant in the unit removal shape, and polishing processing can be performed with good shape accuracy.

FIG. 5 shows the structure of a polishing head 36 as a curved surface polishing apparatus according to the second embodiment of the present invention. In the form of this embodiment, the other structure is the same as that of the first embodiment, and therefore its explanation is omitted. The spindle 51 has a through hole 51B at the center, and a polishing tool 52
A rotary shaft 51A to which an air pump is connected via a joint 70 at an end portion on the opposite side to the housing 71A, 71
Bearings 72A and 72B that are fixed by B and 71C and support the rotating shaft 51A, a servo motor 73 whose rotation speed is controlled by a driver (not shown), an output shaft 73A of the servo motor 73, and the rotating shaft 51A. Drive belt 74. On the other hand, the polishing tool 52 is fixed to the tip of the rotary shaft 51A via a ring 75, and is made up of a bag-shaped member 77 made of an elastic material having a polisher 76 on the outer surface thereof. When the air is sent from the air pump through the through hole 51B, the air is expanded.

Even with such a configuration, since the bag-shaped member 77 absorbs the change in the curvature of the processed surface 34A of the workpiece 34,
The contact area of the polishing tool 52 and the pressing force distribution can be kept constant. Therefore, the unit removal shape can be kept constant even for a workpiece having an aspherical shape without a rotational symmetry axis, and polishing processing can be performed with good shape accuracy.

FIG. 6 shows the structure of a curved surface polishing apparatus according to the third embodiment of the present invention. In this figure
Since the same reference numerals and signs have been used for the same parts as
Duplicate description will be omitted. In this curved surface polishing apparatus, in the first embodiment, the vertical mechanism unit 54 is attached to the X-axis slider 5.
The cylinder portion 7 is fixed to the cylinder portion 7 by controlling the air pressure by an electropneumatic conversion regulator and a driver (not shown).
It is composed of an air cylinder mechanism 79 for raising and lowering 8A, and an arc guide 79 which is supported on the cylinder portion 78 so that the spindle 51 can be rotated about the center of the polishing tool 52 in the arrow γ direction.

The arc guide 79 is provided on the spindle 5 in the normal direction to the machining surface 34A with which the polishing tool 52 comes into contact.
In the rough polishing process in which the angle of the rotary shaft 51A of No. 1 is manually adjustable, and a polishing amount is required, there is an angle between the rotary shaft 51A and the normal to the machining surface 34A with which the polishing tool 52 contacts. In the final polishing step for improving the surface roughness, the posture of the spindle 51 can be changed so that the rotation axis 51A and the normal line direction of the processing surface 34A coincide with each other.

The drive control unit 33A, based on the drive data calculated by the drive calculation unit, the Y-axis mechanism unit 38, which is the horizontal drive axis, the X-axis mechanism unit 53, and the tilt drive axis α.
The drive of the four shafts of the shaft mechanism 39 and the β shaft mechanism 40 is synchronously controlled, and the air pressure of the air cylinder mechanism 78 is controlled.
That is, the pressing force of the polishing tool 52 is controlled. On the other hand, the drive calculation unit calculates the pressing force control data so as to be a value obtained by weighting the reference pressing force value in accordance with the polishing processing amount for bringing the processing surface 34A closer to the target shape for each position. I do.

A curved surface polishing method using the curved surface polishing apparatus according to the third embodiment of the present invention will be described below.

First, in order to perform the rough polishing step of the workpiece 34.
And apply the polishing agent evenly on the processed surface 34A of the processed object 34.
And manually move the spindle 51 along the arc guide 79.
However, the polishing head 36 is attached to the rotary shaft 51A and the polishing tool 5
Between the normal to the machined surface 34A where 2 contacts
Position it so that it has a certain angle. And drive control
By controlling the driver of the air cylinder mechanism 78 of the portion 33A.
The air pressure of the air cylinder mechanism 78 is controlled to
The binder 78A descends, and the polishing tool 52 receives the drive data.
It is pressed on the processing surface 34A by the force based on it. After this, drive
The dynamic control unit 33A controls the servo motor of the spindle 51.
Then, the polishing tool 52 is rotated to move the processing surface 34 of the workpiece 34.
The rough polishing of A is performed. At the same time, the drive control unit 33A
On the basis of the drive data.
45, X-axis mechanism 53 servo motor, α-axis mechanism 3
9 servomotor and β-axis mechanism 40 servomotor
By controlling each driver of 50, the Y-axis table 43, and
The horizontal position of the X-axis slider 57 and the α-axis table 4
7 and the rotation position of the β-axis table 49 are adjusted respectively.
As a result, the polishing head 36 is moved toward the processed surface 34A.
Always point in a certain direction, that is, push the polishing tool 52.
The mounting direction matches the normal to the machined surface 34A, and the rotation axis
51A maintains a predetermined angle with respect to the normal to the machined surface 34A
The processing surface 34A is scanned by the polishing tool 52 as described above. This
, Each point P of the scanning pattern L ₁, P_Two, ...
The height of the machined surface 34A fluctuates due to the drive control unit.
33A of the air cylinder mechanism 78 based on the drive data.
The driver is controlled to raise and lower the cylinder portion 78A.
Therefore, press the polishing tool 52 with a force according to the drive data.
Can be. Next, a finish polishing step for the workpiece 34 is performed.
In order to manually move the spindle 51 along the arc guide 79,
The rotary head 51A with the rotary shaft 51A.
It coincides with the normal line of the processing surface 34A with which the tool 52 contacts.
Take a posture like this. Then, in the same procedure as the rough polishing step
Finish polishing of the work surface 34A is performed. This allows
Rotational motion of the rotating polishing tool 52 on the processing surface 34A
Can be set in all directions, providing a smooth surface with no directivity.
Can be raised.

In the above-described third embodiment of the present invention,
Similar to the first embodiment, the contact area of the polishing tool 52 and the pressing force distribution can be kept constant regardless of the curvature of the processing surface 34A of the workpiece 34, and the workpiece having an aspherical shape can be formed with good shape accuracy. It can be polished. Further, since the polishing amount can be adjusted by adjusting the inclination posture of the spindle 51, the polishing process can be efficiently performed. Furthermore, even if the scanning speed is constant at a low speed, the pressing force of the polishing tool 52 is controlled at each scanning position to adjust the polishing amount, so that it is possible to prevent a reduction in processing accuracy. The same effect can be obtained by controlling the rotation speed of the polishing tool 52 instead of controlling the pressing force of the polishing tool 52.

FIG. 7 shows a scanning pattern of the curved surface polishing apparatus according to the fourth embodiment of the present invention. This curved surface polishing apparatus is configured to perform scanning on the processing surface 34A of the polishing head 32 according to the six divided scanning patterns L _{1 to} L _{6 in the first} embodiment. Around the workpiece 34, the toys 80A to 8A to be discarded
0D is attached, and the polishing start point P _{s with} low processing accuracy is
The polishing end point P _e and the turning point P _r are
It is located on B and 80D. Further, since the processing accuracy tends to be low at both ends of the processed surface 34A, the scanning pattern L ₁ ,
A part of L ₆ is adapted to cover the toy 80A and 80C. The drive control unit 33A and the drive calculation unit sequentially execute the scanning patterns L _{1 to} L ₆ to connect the polishing surfaces.

In the above-described fourth embodiment of the present invention,
Since the scanning pattern of the processed surface 34A is divided, the amount of drive data output at one time from the drive calculation unit is reduced, the memory capacity of the drive control unit can be reduced, and the cost can be reduced.

[0058]

As described above, according to the curved surface polishing method and the curved surface polishing apparatus of the present invention, the pressing direction of the polishing tool is made to coincide with the normal line of the machined surface with a substantially spherical polishing tool having elasticity. Since the polishing surface is scanned and polished while maintaining the rotation axis of the polishing tool at a predetermined angle with respect to the normal to the processing surface, it is possible to improve the processing accuracy of the aspherical workpiece.

Further, the polishing tool can be pressed against the work surface with a constant pressing force irrespective of the position of the polishing tool in the vertical direction, and the drive control in the vertical direction at the time of polishing scanning is not required, so that the structure is simplified. Therefore, the cost can be reduced.

Furthermore, at the time of polishing the machined surface, at least one of the rotation speed of the polishing tool or the pressing force of the polishing tool is synchronously controlled according to the scanning position of the polishing tool.
It is possible to prevent a reduction in processing accuracy due to the scanning speed.

Furthermore, if a tool to be abandoned is attached around the machined surface of the workpiece and the machined surface is polished in accordance with a plurality of divided scanning patterns on the machine, the memory of the drive controller will be described. The capacity can be reduced and the cost can be reduced.

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing a first embodiment of the present invention.

FIG. 2 is an explanatory diagram showing a scanning pattern according to the first embodiment.

FIG. 3 is a cross-sectional view showing the polishing head according to the first embodiment.

FIG. 4 is a graph showing the results of measuring the relationship between the average polishing depth and the change in curvature of the processed surface.

FIG. 5 is a sectional view showing a polishing head according to a second embodiment of the present invention.

FIG. 6 is an explanatory view showing a third embodiment of the present invention.

FIG. 7 is an explanatory view showing a fourth embodiment of the present invention.

FIG. 8 is an explanatory view showing a configuration of a conventional curved surface polishing apparatus.

FIG. 9 is an explanatory view showing a Z tilting device according to a conventional curved surface polishing device.

FIG. 10 is an explanatory view showing a polishing head according to a conventional curved surface polishing apparatus.

[Explanation of symbols]

 1A Shape Measuring Section 1B Polishing Section 2 Surface Plate 3 Workpiece 4 Y-Axis Table 5 Ball Screw 6 Motor 7 X-Axis Table 8 Ball Screw 9 Motor 10 θ Table 11A, 11B, 11C Polishing Frame 12 Mounting Plate 13 Z Tilting Device 14 Polishing Head 15 Triangle mounting plate 16A, 16B Shaft 17A, 17B, 17C Block 18A, 18B, 18C Polishing arm 19A, 19B, 19C Ball screw 20A, 20B, 20C Motor 21A, 21B, 21C Universal joint 22 Polishing head mounting plate 23 Polishing tool 24 Polishing tool holding device 25 Load shaft 26 Constant pressure device 27 Oscillating device 28 Motor 28A Output shaft 29 Crank 30 Connecting rod 31 Slide shaft 32 Slider 33 Support surface plate 33A Drive controller 34 Workpiece 34A Work surface 35 Cable drive unit 36 polishing head 37 support mechanism unit 38 Y-axis mechanism unit 39 α-axis mechanism unit 40 β-axis mechanism unit 41 fixing jig 42A, 42B guide 43 Y-axis table 44 ball screw 45 servo motor 46 arc guide 46A arc surface 47 α Axis table 47A Arc surface 48 Arc guide 48A Arc surface 49 β Axis table 49A Arc surface 50 Servo motor 51 Spindle 51A Rotating shaft 52 Polishing tool 53 X axis mechanism 54 Vertical mechanism 55A, 55B Strut 56 Guide 57 X axis slider 58 Slide Mechanism part 58A Slider 59A, 59B Pulley 60 Weight 61 Wire 62 Servo motor 63 Coupling 64A, 64B Housing 65A, 65B Bearing 66 Fixing pin 67 Tool shaft center 67A Spherical part 68 Elastic body 69 Polisher 70 Yointo 71A, 71B, 71C housing 72A, 72B bearings 73 servo motor 73A output shaft 74 drive belt 75 ring 76 polisher 77 bag-like member 78 an air cylinder mechanism 78A cylinder 79 arc guide 80A~80D lens holder unit

Continued front page (72) Inventor Takaaki Sakakibara 2274 Hongo, Ebina City, Kanagawa Prefecture Fuji Xerox Co., Ltd.Ebina Business Office (72) Inventor, Hisasa Fujisawa 430, Nakai-cho, Ashigagami-gun, Kanagawa Prefecture Green Tech Nakai Fuji Xerox Co., Ltd.

Claims (29)

[Claims] 1. A substantially spherical polishing tool having elasticity is prepared, and a normal line of a processing surface of a workpiece which changes according to a surface shape and a pressing direction of the polishing tool are matched to each other with a predetermined pressing force. While pressing the polishing tool against the working surface, the polishing tool is rotated about a predetermined rotation axis, and the angle between the normal and the predetermined rotation axis of the polishing tool is maintained at a predetermined angle. Meanwhile, the curved surface polishing method is characterized in that the processing surface is scanned by the polishing tool to polish the processing surface. 2. The polishing tool is prepared by providing a polisher on the surface of a substantially spherical elastic body having a diameter of 50 mm or less and an elastic modulus of 1 kgf / mm ² or less.
The curved surface polishing method described. 3. The curved surface polishing method according to claim 1, wherein the polishing tool is prepared by supplying a fluid to a bag-shaped member made of an elastic material having a polisher on its surface to expand the bag into a spherical shape having a predetermined size. . 4. Matching of the pressing direction of the polishing tool with respect to the normal line and maintaining a predetermined angle of the predetermined rotation axis of the polishing tool with respect to the normal line are maintained in a predetermined posture. 2 orthogonal to the tool on the horizontal plane
The curved surface polishing method according to claim 1, which is performed by rotating the workpiece around an axis. 5. The polishing of the processed surface includes rough polishing performed by setting the predetermined angle to an angle larger than 0 and finish polishing performed by setting the predetermined angle to 0. Curved surface polishing method. 6. The work piece has a tool to be a processing waste portion around the work surface, and the work surface is polished according to a plurality of scanning patterns divided on the tool. The curved surface polishing method described. 7. A substantially spherical polishing tool having elasticity is prepared, and the pressing line of the polishing tool is aligned with the normal of the processing surface of the workpiece that changes according to the surface shape, and a predetermined pressing force is applied to the polishing tool. While pressing the polishing tool against the working surface, the polishing tool is rotated about a predetermined rotation axis, and the angle between the normal and the predetermined rotation axis of the polishing tool is maintained at a predetermined angle. While polishing the processing surface by scanning the processing surface with the polishing tool, during polishing of the processing surface, the rotation speed of the polishing tool or the pressing force of the polishing tool according to the polishing position of the polishing tool A curved surface polishing method, characterized in that at least one of the above is controlled. 8. The polishing tool is prepared by providing a polisher on the surface of a substantially spherical elastic body having a diameter of 50 mm or less and an elastic modulus of 1 kgf / mm ² or less.
The curved surface polishing method described. 9. The method of polishing a curved surface according to claim 7, wherein the polishing tool is prepared by supplying a fluid to a bag-shaped member made of an elastic material having a polisher on its surface to expand the bag into a spherical shape having a predetermined size. . 10. Matching of the pressing direction of the polishing tool with respect to the normal line, and maintaining a predetermined angle of the predetermined rotation axis of the polishing tool with respect to the normal line, the polishing held in a predetermined posture The curved surface polishing method according to claim 7, which is performed by rotating the workpiece around two axes orthogonal to each other on a horizontal plane with respect to the tool. 11. The polishing of the machined surface includes rough polishing performed by setting the predetermined angle to an angle larger than 0 and finish polishing performed by setting the predetermined angle to 0. Curved surface polishing method. 12. The work piece has a tool to be a part to be processed around the work surface, and the work surface is polished according to a plurality of scanning patterns divided on the tool. The curved surface polishing method described. 13. A substantially spherical polishing tool having elasticity, pressing means for pressing the polishing tool against a work surface of a workpiece in a predetermined pressing direction with a predetermined pressing force, and rotating the polishing tool in a predetermined rotation. Rotating means for rotating about an axis; horizontal displacing means for displacing the relative position of the workpiece and the polishing tool in the horizontal direction; a normal line of the processing surface of the workpiece and the predetermined rotation of the polishing tool. An axis, an angle changing means for changing the relative angle of the predetermined pressing direction, and the horizontal displacing means to cause the polishing tool to scan the machining surface and to control the angle changing means. Control means for polishing the machined surface by making the normal line coincide with the pressing direction of the polishing tool and maintaining the angle between the normal line and the predetermined rotation axis of the polishing tool at a predetermined angle. Equipped with It curved polishing apparatus according to claim. 14. The curved surface polishing apparatus according to claim 13, wherein the polishing tool comprises a substantially spherical elastic body having a diameter of 50 mm or less and an elastic modulus of 1 kgf / mm ² or less, and a polisher provided on the surface thereof. . 15. The polishing tool has a bag-shaped member made of an elastic material and a polisher provided on the surface of the bag-shaped member, and supplies a fluid to the bag-shaped member to form a substantially spherical ball of a predetermined size. 14. The curved surface polishing apparatus according to claim 13, wherein the curved surface polishing apparatus is formed by inflating into a shape. 16. The curved surface polishing apparatus according to claim 13, wherein the angle changing means is constituted by a workpiece rotating means for rotating the workpiece around two axes orthogonal to each other on a horizontal plane. 17. The rotating means is configured to set the predetermined angle to an angle larger than 0 in a rough polishing step and set the predetermined angle to 0 in a final polishing step. 13. The curved surface polishing apparatus described in 13. 18. The work piece has a tool to be a processing waste portion around the work surface, and the control means polishes the work surface of the polishing tool.
14. The curved surface polishing apparatus according to claim 13, wherein the curved surface polishing apparatus is performed according to a plurality of scanning patterns divided on the toy. 19. The curved surface polishing apparatus according to claim 13, wherein the pressing means has a pressing force applying means for applying the predetermined pressing force regardless of the vertical position of the polishing tool. 20. The pressing force applying means is a weight balance mechanism that generates the predetermined pressing force based on a difference between the weight of the polishing tool and the weight of the support that supports the polishing tool. 19. The curved surface polishing apparatus described in 19. 21. The curved surface polishing apparatus according to claim 19, wherein the pressing force applying means is a cylinder mechanism that generates an internal pressure according to a reaction force that the polishing tool receives from the processing surface. 22. A substantially spherical polishing tool having elasticity, a pressing means for pressing the polishing tool against a processing surface of a workpiece with a predetermined pressing force in a predetermined pressing direction, and rotating the polishing tool in a predetermined rotation. Rotating means for rotating about an axis; horizontal displacing means for displacing the relative position of the workpiece and the polishing tool in the horizontal direction; a normal line of the processing surface of the workpiece and the predetermined rotation of the polishing tool. An axis, an angle changing means for changing the relative angle of the predetermined pressing direction, and the horizontal displacing means to cause the polishing tool to scan the machining surface and to control the angle changing means. Match the pressing direction of the polishing tool with the normal,
And, comprising a control means for polishing the processing surface by maintaining an angle between the normal line and the predetermined rotation axis of the polishing tool at a predetermined angle, the control means, when polishing the processing surface, A curved surface polishing apparatus, wherein at least one of a rotation speed of the polishing tool and a pressing force of the polishing tool is controlled according to a polishing position of the polishing tool. 23. The curved surface polishing apparatus according to claim 22, wherein the polishing tool comprises a substantially spherical elastic body having a diameter of 50 mm or less and an elastic modulus of 1 kgf / mm ² or less, and a polisher provided on the surface thereof. . 24. The polishing tool has a bag-shaped member made of an elastic material and a polisher provided on the surface of the bag-shaped member, and supplies a fluid to the bag-shaped member to form a substantially spherical ball of a predetermined size. The curved surface polishing apparatus according to claim 22, wherein the curved surface polishing apparatus is formed by inflating the shape. 25. The curved surface polishing apparatus according to claim 22, wherein the angle changing means is constituted by a workpiece rotating means for rotating the workpiece around two axes orthogonal to each other on a horizontal plane. 26. The rotating means is configured to set the predetermined angle to an angle larger than 0 in a rough polishing step and set the predetermined angle to 0 in a final polishing step. 22. The curved surface polishing apparatus described in 22. 27. The workpiece has a tool to be a processing waste portion around the processing surface, and the control means polishes the processing surface of the polishing tool.
23. The curved surface polishing apparatus according to claim 22, wherein the curved surface polishing is performed according to a plurality of scanning patterns divided on the unit. 28. The curved surface polishing apparatus according to claim 22, wherein the pressing means has a pressing force applying means for applying a predetermined pressing force regardless of the vertical position of the polishing tool. 29. The curved surface polishing apparatus according to claim 28, wherein the pressing force applying means is a cylinder mechanism that generates an internal pressure according to a reaction force that the polishing tool receives from the processing surface.