JPH10230448A - Method and apparatus for polishing free-form surface - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To efficiently and accurately polish an aspherical surface of a free-form surface having an asymmetrical rotation axis. SOLUTION: A tip of a tool 23A is set to a work 9 at a predetermined pressure.
In a method of polishing a free-form surface, the workpiece mounting table 18 on which the workpiece 9 is placed is controlled to move in an XY direction and an A direction around an axis parallel to the X axis while being pressed against the surface. , The work mounting table 18
Is further configured to be movable in a B direction around an axis parallel to the Y axis, and to control the four directions of the X, Y, A, and B directions based on machining data calculated in advance from a workpiece shape. Then, the tool 23A and the work 9 are relatively positioned, and the polishing is performed by making the rotation axis of the tool 23A or an arbitrary part of the tool surface coincide with the normal direction at each processing point of the work. It is characterized by the following.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polishing method and apparatus for polishing a free-form surface while imitating the surface with a tool, and more particularly, to a workpiece on which a workpiece is placed with a tool tip pressed against the workpiece surface at a predetermined pressure. Polishing a free-form surface while controlling the movement of the mounting table in the XY direction and the A direction around an axis parallel to the X axis, and further controlling the movement in the B direction around an axis parallel to the Y axis. Method and apparatus.

[0002]

2. Description of the Related Art Conventionally, a polishing method and apparatus for polishing a free-form surface while following a tool with a tool have been disclosed in Japanese Patent Application Laid-Open No. 53-140.
No. 694 (Prior Art 1) and Japanese Patent Publication No. 1-55946 (Prior Art 2).

[0003] In the prior art example 1, the tool and the surface of the workpiece are in point contact with each other, and a mark is formed on the surface of the workpiece, so that a high-precision surface roughness cannot be obtained. The tool is made of an elastic material, and the tool is deformed following the surface of the workpiece.

[0004] However, even if the tool is formed of an elastic body, if the polished surface of the workpiece does not coincide with the tool axis, the tool is in uneven contact with the surface of the workpiece, and the polished surface of the tool is not constant. There is a problem that the tool is unevenly worn and the pressing force of the tool on the surface of the workpiece is not constant, so that high-precision surface roughness cannot be obtained. Prior example 2 in which the surface and the tool axis coincide with each other is known.

In this prior art example 2, a work piece is mounted on a mounting table, and the mounting table is rotated, and the mounting table moves in a radial direction, and the surface of the work piece is polished spirally by a rotating tool. Is what you do. In order to polish an aspherical surface symmetrical with respect to the rotation center axis of the mounting table, the prior example 2 sets the rotation axis of the tool as the Z axis, and aligns the rotation center axis of the mounting table with the Z axis. In the Y-axis direction of the aspherical surface symmetrical on the rotation center axis, when the mounting table is moved so that the tool follows, since the mounting table is rotating, in one radial direction from the rotation center axis of the mounting table. By moving the mounting table, the aspheric surface can be polished only by the tool following the radial aspheric surface.

[0006]

However, FIG.
, The aspherical surfaces N of the workpieces 180A and 180B
1, N2 (a) or R1, R2 (b) are asymmetrical planes P1, P2 (a) or Q on the rotation center axis K of the mounting table.
1, Q2 (b), P1 and P2 or Q1 and Q2 which are equidistant from the rotation center axis K are not equidistant from the reference plane V in the direction of the arrow, but are lines L which form an aspheric surface. , Or on S.

Therefore, the prior art example 2 is asymmetric in that the mounting table is moved in one radial direction from the rotation center axis K of the rotating mounting table, and the tool only follows the aspheric surface in the radial direction. Cannot be polished, and it is necessary to perform correction following the line L or S.

In view of the above-mentioned circumstances, an object of the present invention is to provide a method and an apparatus capable of efficiently and accurately polishing an aspherical surface having a rotational axis asymmetric among free-form surfaces.

[0009]

According to a first aspect of the present invention, there is provided a work mounting table on which a work is placed with a tool tip pressed against a work surface at a predetermined pressure. In the method of polishing a free-form surface for polishing a work surface while controlling movement in an XY direction and an A direction around an axis parallel to the X axis, the work mounting table may further include a B direction about an axis parallel to the Y axis. And controllable movement based on the machining data calculated from the workpiece shape.
The tool and the work are relatively positioned by controlling the four directions of the X, Y, A and B directions, and the rotation axis of the tool or the tool surface is set in the normal direction at each processing point of the work. It is characterized in that polishing is performed by matching arbitrary parts.

The first invention, as shown in FIGS. 1 and 2, employs a work mounting table 18 on which a work is placed with the tip of a tool 23A pressed against the surface of the work with a predetermined pressure.
XY by the X-axis table 12 and the Y-axis table 13
This is a free-form surface polishing method for polishing the work surface while controlling the movement in the direction and in the direction A about an axis parallel to the X-axis by the A-axis positioning mechanism 17.

The work mounting table 18 is
Further, the B-axis positioning mechanism 15 is configured to be able to control the movement in the B-direction around an axis parallel to the Y-axis, and the four directions of the X, Y, A and B directions are determined based on the processing data calculated from the work shape. By controlling, the tool 23A and the work are relatively positioned, and the grinding process is performed such that the rotation axis of the tool 23A or an arbitrary part of the tool surface coincides with the normal direction at each processing point of the work. .

Therefore, the work mounting table 18 is
In addition to the conventional control in the X, Y, and A directions, the B-axis positioning mechanism 15 enables movement control in the B direction about an axis parallel to the Y axis. The positioning mechanism 15 can efficiently polish the aspherical surface having a rotational axis asymmetric among free-form surfaces.

According to a second aspect of the present invention, the work mounting table on which the work is placed is moved in the XY directions and the A direction around an axis parallel to the X axis while the tool tip is pressed against the work surface with a predetermined pressure. In the method of polishing a free-form surface for polishing a work surface while controlling movement, a spindle having means for attaching a tool to a shaft end and having a spindle which can be tilted and positioned with respect to a vertical axis, based on processing data calculated from a work shape, The X, Y, A and four directions of the tilting movement of the spindle are controlled to relatively position the tool and the work, and the rotation axis of the tool or the rotation axis of the tool in the normal direction at each processing point of the work. It is characterized in that an arbitrary part of the tool surface is made to match and polished.

The first and second aspects are the same in that the movement of the work mounting table is controlled in the XY directions and in the A direction around an axis parallel to the X axis. According to the first aspect, the work mounting table can be further controlled to move in a direction B around an axis parallel to the Y axis, while the second aspect is a means for mounting a tool to a shaft end. And a spindle shaft 9B (FIG. 3) capable of tilting and positioning with respect to the vertical axis, and controls four directions of X, Y, A and the tilting movement direction of the spindle.

Therefore, the work mounting table 18 is
In addition to the control in the X, Y, and A directions conventionally used, the spindle 23B having means for attaching the tool 23B to the shaft end can control the tilt position of the tool 23B with respect to the vertical axis. In addition, the spindle 22B can efficiently polish an aspherical surface having a rotational axis asymmetric among free-form surfaces.

Further, in the method for polishing a free-form surface according to the first and second aspects, the work mounting table may be mounted on an A positioning mechanism having an angle indexing function capable of moving in an A direction about an axis parallel to the X axis. It is also an effective means of the first or second invention that the apparatus is rotatably mounted and configured to perform polishing by rotating the work mounting table.

As described above, by further controlling the rotation of the work, the position control in five directions can be performed by adding the rotation of the work to the movement control in the X, Y, A and B directions of the first aspect. Further, in addition to the control of the inclination movement direction of X, Y, A and the spindle according to the second aspect, the rotation of the work can be added to control the position in five directions. Therefore, the aspherical surface having the rotational axis asymmetrical among the free-form surfaces can be more efficiently polished.

According to a third aspect of the present invention, the work mounting table on which the work is placed is moved in the XY directions and the A direction around an axis parallel to the X axis while the tool tip is pressed against the work surface with a predetermined pressure. An A-axis positioning mechanism with an angle indexing function that rotates and positions around an axis parallel to the X-axis, and a rotary positioning around an axis parallel to the Y-axis in a free-form surface polishing device that grinds the work surface while controlling the movement of the workpiece. A B-axis positioning mechanism having an angle indexing function to perform, and a work mounting table arranged on a positioning mechanism located at an upper part of the B-axis positioning mechanism and the A-axis positioning mechanism, and machining data calculated from a work shape. Based on
The X-axis positioning mechanism, the Y-axis positioning mechanism, the B
The tool and the work are relatively positioned by four means of an axis positioning mechanism and the A-axis positioning mechanism, and a rotation axis of the spindle or an arbitrary part of the tool surface is arranged in a normal direction at each processing point of the work. It is characterized by being polished by matching.

According to the third invention, as shown in FIGS. 1 and 2, a work mounting table 18 on which a work is placed with the tip of a tool 23A pressed against the work surface at a predetermined pressure.
XY by the X-axis table 12 and the Y-axis table 13
This is a free-form surface polishing apparatus for polishing the work surface while controlling the movement in the direction A and the direction A around an axis parallel to the X-axis by the A-axis positioning mechanism 17.

An A-axis positioning mechanism 17 having an angle indexing function for rotating and positioning around an axis parallel to the X-axis, and a B-axis positioning mechanism 15 having an angle indexing function for rotating and positioning around an axis parallel to the Y-axis. The mounting positions of the A-axis positioning mechanism 17 and the B-axis positioning mechanism 15 may be either up or down in the figure. That is, in FIG. 1, the A-axis positioning mechanism 17 is rotatably attached to the supporting part 16 erected on the B-axis positioning means 15. The B-axis positioning mechanism 15
May be attached.

Further, a work mounting table 18 is provided which is disposed on a positioning mechanism located at an upper part of the B-axis positioning mechanism 15 and the A-axis positioning mechanism. The X-axis positioning mechanism (X-axis table) 12, the Y-axis positioning mechanism (Y-axis table) 13, the B-axis positioning mechanism 15, and the A-axis positioning mechanism 17 are based on the processing data calculated from the workpiece shape. The tool 23A and the work are relatively positioned by the four mechanisms, and the spindle 22 is moved in the normal direction at each processing point of the work.
Polishing is performed by matching the rotation axis of A or an arbitrary portion on the tool surface.

Therefore, the work mounting table 18 is
In addition to the conventional control in the X, Y, and A directions, the B-axis positioning mechanism 15 allows movement control in the B direction about an axis parallel to the Y axis. The positioning mechanism 15 can efficiently polish the aspherical surface having a rotational axis asymmetric among free-form surfaces.

Further, since the rotation axis of the spindle 22A coincides with the normal direction at each processing point of the work for polishing, the predetermined lower surface of the tool coincides with the normal direction of the polished surface of the work. If the polished surface is constant and the predetermined surface has no corners or the like, preferably, if the surface is formed by an R surface, a curved surface, or the like, the tool is biased against the work surface of the work surface to generate a mark on the work surface. Nothing.

Also, even if the rotation axis of the spindle 22A does not coincide with the normal direction at each processing point of the work,
When any part of the tool surface is matched, the polished surface of the tool is constant in the same manner as described above, the predetermined surface has no corners, etc., preferably, if it is formed by an R surface, a curved surface, etc. The tool does not hit the work surface of the work surface unevenly to form a mark on the work surface.

According to a fourth aspect of the present invention, the work mounting table on which the work is placed is moved in the XY direction and the A direction around an axis parallel to the X axis while the tool tip is pressed against the work surface with a predetermined pressure. In a free-form surface polishing apparatus for polishing a work surface while controlling the movement of the workpiece, an A-axis positioning mechanism having an angle indexing function of rotating and positioning around an axis parallel to the X-axis, and an A-axis positioning mechanism arranged on the A-axis positioning mechanism, A work mounting table having an indexing function for controlling rotation, a means for mounting a tool to the shaft end, a spindle capable of tilting and positioning with respect to a vertical axis, and the X, Y based on machining data calculated from a work shape. , A
And controlling the four directions of the tilting movement direction of the spindle to relatively position the tool and the work, and any position of the rotation axis of the tool or the tool surface in the normal direction at each processing point of the work. It is characterized in that it is polished by matching the parts.

According to a fourth aspect of the present invention, there is provided an angle for generating a desired pressing force on a tool, controlling the movement in the Z direction, and rotating and positioning the work mounting table in the XY directions and about an axis parallel to the X axis. This is the same in that an A-axis positioning mechanism having an indexing function is provided and movement control is performed in the A direction.

A fourth aspect of the present invention provides a B-axis positioning mechanism having an angle indexing function for rotating and positioning the work mounting table about an axis parallel to the Y-axis.
In the shaft positioning mechanism, the work mounting table is disposed on the A-axis positioning mechanism to provide an angle indexing function. A spindle 22B (FIG. 3) that controls the rotation and has means for attaching a tool to the shaft end is provided.
The tilt position can be set with respect to the vertical axis.
Y, A, and four directions of the tilt movement direction of the spindle shaft are controlled.

Therefore, the work mounting table 18 is
In addition to the control in the X, Y, and A directions conventionally used, the spindle 23B having means for attaching the tool 23B to the shaft end can control the tilt position of the tool 23B with respect to the vertical axis. In addition, the spindle 22B can efficiently polish an aspherical surface having a rotational axis asymmetric among free-form surfaces.

In the apparatus for polishing a free-form surface according to claims 4 and 5, the work mounting table is mounted on an A positioning mechanism having an angle indexing function capable of moving in an A direction about an axis parallel to the X axis. It is also an effective means of the third or fourth aspect of the present invention that the work is rotatably mounted and configured to carry out polishing by rotating the work mounting table.

As described above, by further controlling the rotation of the work, the position of the work can be controlled in five directions by adding the rotation of the work to the movement control in the X, Y, A and B directions. Further, in addition to the control of the inclination movement direction of X, Y, A and the spindle according to the fifth aspect, the rotation of the work can be added to control the position in five directions. Therefore, the aspherical surface having the rotational axis asymmetrical among the free-form surfaces can be more efficiently polished.

[0031]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to an embodiment shown in the drawings. However, the dimensions, materials, shapes, relative arrangements, and the like of the components described in this embodiment are not intended to limit the scope of the invention thereto, but are merely illustrative examples unless otherwise specified. Not just.

FIG. 1 is a front view of a polishing apparatus according to an embodiment of the present invention, and FIG. 2 is a side view of FIG. In these figures, the polishing machine 1 includes a tool control unit 31 provided on a column 11 standing upright at a rear end of a base 10 and a base 1.
The work control unit 32 is provided with the work control unit 32.

The work control unit 32 includes a Y-axis table 13 that can reciprocate in the Y-axis direction on the base 10,
An X-axis table 12 that can reciprocate in the X direction on an axis table 13 and an angle index that is provided on a support portion 14 that stands upright on the rear end of the X-axis table 12 and that rotates and positions around an axis parallel to the Y axis. B-axis positioning mechanism 1 with function
5 and an A-axis positioning mechanism 1 provided on a support 16 standing upright at one end of the B-axis positioning mechanism 15 and having an angle indexing function for rotating and positioning around an axis parallel to the X-axis.
7 and a work mounting table 18 mounted on the A-axis positioning mechanism 17.

The tool control unit 31 is provided with a Z-axis positioning mechanism 19 which is vertically movable with respect to the column 11 in the Z direction (vertically), and a support unit integrally mounted on the Z-axis positioning mechanism 19. A motor 20 for driving the Z-axis positioning mechanism 19 is provided above the column 11.
Is installed. A pneumatic cylinder 25 is mounted on the support portion 30, and a piston rod 24 connected to a piston 25A projects through the support portion 30 and is connected to a spindle 22A described later.

A spindle support 21A is mounted on the side of the Z-axis positioning mechanism 19, and a spindle 22A is disposed in the spindle support 21A in parallel with the Z-axis. Are linked. The spindle 22A is rotatably mounted on the spindle support 21A, but is configured so that rotation is not transmitted to the piston rod 24. And Z
The spindle 22A is rotated by the motor 4 attached to the side of the shaft positioning means 19. This spindle 2
The tool 23A is configured to be mounted on the lower end of 2A.

Further, a piston position detector 2 is provided at an outer intermediate portion of the air cylinder 25. When the piston 25A descends and comes close to the detector, the signal is transmitted to a control circuit described later. Is sent as a start signal. The air cylinder 25 is connected to an air pressure source via a pressure control valve (not shown), and a constant air pressure set by the pressure control valve is applied to the upper chamber of the piston 25a.

Next, the components constituting the work control section 32 will be described in more detail. Y of work control unit 32
The axis table 13 has a built-in Y-axis control motor 8 and an encoder 13 for detecting the rotation angle of the motor 8.
1 is provided, is reciprocally movable on the base 10 in the Y-axis direction, and its movement amount is detected. X axis table 1
2, an X-axis control motor 7 is built in, and an encoder 121 for detecting the rotation angle of the motor 7 is provided. The encoder 121 can reciprocate in the X-axis direction on the Y-axis table. Is detected.

A B-axis control motor 6 is built in a support 14 standing upright at the rear end of the X-axis table 12.
An encoder 151 for detecting the rotation angle of the motor 6 is provided. Rotation positioning is possible around an axis parallel to the Y axis, and the amount of movement is detected. B axis positioning mechanism 15
The A-axis control motor 5 is disposed on the support 16 standing upright at one end of the frame, and an encoder 171 for detecting the rotation angle of the motor 5 is provided. The encoder 171 can be rotated and positioned around an axis parallel to the X-axis. , The amount of movement is detected.

Next, an electrical block diagram of the polishing apparatus for controlling various mechanisms of the above-described polishing apparatus will be described. FIG.
FIG. 1 is a basic configuration diagram showing an electrical block configuration according to the present embodiment. The CPU 100 includes a workpiece shape storage unit 98, a tool path data storage unit 90 for moving a polishing tool according to the surface shape of the workpiece, and a control program for the polishing apparatus to grind the workpiece surface. The stored control program storage means 89 is connected.

The CPU 100 has an interface 1
The control circuit 120 is connected to the control circuit 120 via the control unit 10 so as to calculate data from the various storage units and data received from the control circuit 120 and transmit a command signal to the control circuit 120.

The control circuit 120 includes tool control means 97A,
The work control means 96A is connected. Among these control means, the tool control means 97A activates the Z-axis positioning means 94 in response to a start signal 124 from the control circuit 120, and further outputs a detection signal from the position detector 2. The drive signal is transmitted thereafter, and the Z-axis positioning means 94 is stopped, the tool rotation is started, and an operation signal is transmitted to the work control means. Then, a signal is sent to the motor 20 via the Z-axis positioning means 94 by a forced stop signal 125 or a stop signal sent from the control circuit 120 in synchronization with the end of the operation of the work control means 96A, and the motor 20 is rotated in the reverse direction. Then, the Z-axis positioning mechanism 19 is returned to the initial position, and the tool rotation motor 4 is stopped. The work rotation control means 88 is connected and configured as needed, and contributes to the polishing operation of the workpiece surface in an embodiment described later, and will be described in detail later.

As shown in FIG. 7, the tool control means 97A
The motor 20 is used for positioning the tool, returning the Z-axis positioning mechanism 19 to the initial position, and driving the tool to rotate. The motor 20 rotates by the start signal 124 and drives the Z-axis positioning mechanism 19. Tool 23A
When the piston 25A retreats to the intermediate position after contacting the workpiece 9, a detection signal is sent out, and the position detector 2 (FIG. 2) for stopping the motor 20 is provided. The Z-axis positioning means 94 for returning the Z-axis positioning mechanism 19 to the initial position by reversing the motor 20 in response to a stop signal sent upon completion of the driving of the means 96A, and starts operation by a signal from the control circuit 120. The control circuit 120 is configured to send a drive signal to the work control means 96A when the rotation signal to the motor 4 reaches a constant speed.

As shown in FIG. 8, the work control means 96A
Are connected to the CPU 100 via the control circuit 120, and have control means for controlling the movement of the work mounting table 18 in the X, Y, A, and B axis directions. The A-axis control means 93 is a control means for controlling the movement of the work around an axis parallel to the X-axis. The A-axis control means 93 is connected to the A-axis control motor 5 and the encoder 171, and the rotation amount of the motor 5 from the encoder 171. Is detected, and the rotation of the motor 5 is controlled.

The B-axis control means 92 is a control means for controlling the movement of the work around an axis parallel to the Y-axis.
It is connected to the shaft control motor 6 and the encoder 151 so as to detect the amount of rotation of the motor 6 from the encoder 151 and to control the rotation of the motor 6.

The X-axis control means 91 is a control means for controlling the movement of the work in the X-axis direction. The X-axis control means 91 is connected to the X-axis control motor 7 and the encoder 121, and
The rotation amount of the motor 7 is detected from 21 and the rotation of the motor 7 is controlled.

The Y-axis control means 90 is a control means for controlling the movement of the work in the Y-axis direction.
The rotation amount of the motor 8 is detected from 31 and the rotation of the motor 8 is controlled.

Next, the operation of the present embodiment configured as described above will be described. When a switch on a control panel (not shown) is turned on, a start signal 124 enters the motor 20 via the control circuit 120, and the motor 20 is driven to start lowering the Z positioning mechanism 19. At the same time, the work mounting table 18 is positioned so that a predetermined position of the work comes to a preset processing start point.

Although the Z-axis positioning mechanism 19 continues to descend, the piston rod 24 and the piston 25A connected to the spindle 22A in FIG. 2 are stopped at the position where they contact the work surface. When the position 25A is moved to the intermediate position by ascending, the position detector 2 is turned on, the motor 20 is turned off by this signal, the Z-axis positioning mechanism 19 is stopped, and the motor 4 is turned on by the signal from the control circuit 120. Turn ON to start tool rotation. And when this rotation reaches a certain number of rotations,
A drive signal is sent from the control circuit 120 in FIG.

Upon receipt of this drive signal, processing is started. That is, since the tool is brought into contact with the machining start position of the workpiece at a constant pressure in advance, the X, Y, X, Y, The A and B axis control means are operated, and the work position is controlled such that the tool tip is always in normal contact with the work processing point, so that processing is performed.
From the polishing start point to the polishing end point, N
Interpolation is performed using a linear interpolation function or an arc interpolation function in C control, and polishing is continuously performed.

7 and 10 when the stop signal 125 (FIGS. 6 and 9) is forcibly input to the control circuit 120 during the polishing operation, or when a predetermined polishing operation is completed.
As shown in (2), the control circuit 120 sends a stop signal to the Z-axis positioning means 94. The Z-axis positioning means 94 stops the tool rotation motor 4 and reverses the motor 20 to raise the Z-axis positioning mechanism 19. And return to the initial position.

Since the present embodiment is configured as described above, the work mounting table on which the work is placed is moved in the X and Y directions while the tip of the tool is pressed against the work surface at a predetermined constant pressure. While controlling the movement in the direction A around the axis parallel to the axis, the work mounting table is further moved.
Since the movement can be controlled in the B direction around the axis parallel to the Y axis, the four directions of the X, Y, A and B directions are controlled based on machining data calculated in advance from the work shape, The tool 23A and the work are relatively positioned, and the tool 23A is positioned in the normal direction at each processing point of the work.
Polishing is performed with the rotation axis of A aligned.

Therefore, the work mounting table 18 is
In addition to the conventional control in the X, Y, and A directions, the B-axis positioning mechanism 15 enables movement control in the B direction about an axis parallel to the Y axis. The positioning mechanism 15 can efficiently polish the aspherical surface having a rotational axis asymmetric among free-form surfaces.

Next, a second embodiment shown in FIG. 3 will be described. The difference from the first embodiment described above is that, in the first embodiment, the work mounting table 18 can be adjusted by providing a B-axis control unit 92 that can rotate around an axis parallel to the Y-axis. On the other hand, in the second embodiment,
Instead of the B-axis control means 92, the spindle which holds the tool in the same direction as the B-axis control direction is configured to be tilt-controlled. Mechanically, as shown in FIG.
The A-axis positioning mechanism 17 is directly connected to the X-axis table
B, a tool tilting motor 27 is provided, and the tool 27 is configured to be tiltable by the motor 27. Other than that, the configuration of the tool control unit and the work control unit is different as described later.

As shown in FIG. 10, the tool control means 97B in the second embodiment is different from the tool control means 97A in the first embodiment shown in FIG.
7 is attached.

The tool spindle inclination control means 87 in the second embodiment is provided in place of the above-described B-axis control means 92, and has a similar function. Therefore, as shown in FIG. , Tool spindle tilt control means 8
Numeral 7 denotes a spindle 22B which is connected to the piston rod side in the axial direction, is mounted on the spindle support 21B, and can be tilted and positioned with respect to the vertical axis by a motor 27 (with an encoder).

Then, the same operation as the B axis control means in the first embodiment shown in FIG. 8 is performed, and the surface contact of the workpiece to be polished in conjunction with the control of the other X, Y, and A axes is brought into contact with the tool. Polishing is performed while controlling the state so as to always face the normal direction.

Therefore, the work mounting table 18 is
In addition to the control in the X, Y, and A directions conventionally used, the spindle 23B having means for attaching the tool 23B to the shaft end can control the tilt position of the tool 23B with respect to the vertical axis. In addition, as in the case of the B-axis control described above, the spindle 22B can efficiently polish an aspherical surface having a rotational axis asymmetric among free-form surfaces.

FIG. 4 shows a third embodiment in which a work rotation drive mechanism 26 incorporating a work rotation motor 28 is interposed between the A-axis positioning mechanism 17 and the work mounting table 18 in the first embodiment. It shows. As shown in FIG. 6, the work rotation drive mechanism 26 includes a control circuit 1
20 and the work rotation motor 28
The work rotation drive mechanism 26 and the work rotation motor 2 are connected to an encoder 128 so as to rotate the motor 28 and also to feed back a signal of the motor movement amount from the encoder 128.
8 and encoder 128 to work rotation control means 88
Is composed.

FIG. 5 shows a fourth embodiment in which a work rotation drive mechanism 26 incorporating a work rotation motor 28 is interposed between the A-axis positioning mechanism 17 and the work mounting table 18 in the second embodiment. It shows. As shown in FIG. 9, the work rotation drive mechanism 26 includes a control circuit 1
20 and the work rotation motor 28
The work rotation drive mechanism 26 and the work rotation motor 2 are connected to an encoder 128 so as to rotate the motor 28 and also to feed back a signal of the motor movement amount from the encoder 128.
8 and encoder 128 to work rotation control means 88
Is composed.

In the third and fourth embodiments, the work mounting table is mounted on the workpiece mounting table around an axis parallel to the X axis.
It is configured to be rotatably mounted on an A positioning mechanism having an angle indexing function capable of moving in the direction, and to be polished by rotation of the work mounting table. By controlling
Position control in five directions can be performed by adding the rotation of the work to the movement control in the X, Y, A and B directions. X, Y,
Position control in five directions can be performed by adding the rotation of the work to the tilt movement direction control of the A and the spindle. Therefore,
An aspherical surface having a rotational axis asymmetric among free-form surfaces can be more efficiently polished.

As described in detail above, in the present embodiment, the polishing is performed by making the rotation axis of the spindle coincide with the normal line direction at each processing point of the work. Since it coincides with the line direction, the polished surface of the tool is constant, and the predetermined surface has no corners or the like.
If the surface is formed of a surface, a curved surface, or the like, the tool does not hit the machined surface of the work surface to form a mark on the work surface.

Even if the rotation axis of the spindle does not coincide with the normal direction at each machining point of the work, if the arbitrary part of the tool surface is matched, the polished surface of the tool becomes constant as described above. However, if the predetermined surface has no corners or the like, and is desirably formed of an R surface, a curved surface, or the like, the tool does not hit the machined surface of the work surface to form a mark on the work surface.

Although the positioning mechanism in each axial direction is shown as a cantilever in the supporting portion for the sake of explanation, it is needless to say that both ends support and other practically preferable changes are within the scope of the present embodiment. It is. FIG. 7 shows an example in which a signal from the position detector 2 is used as a drive signal to the work control means. In FIG. 7, a signal from the position detector 2 is input to the tool rotation motor 4. After starting rotation from, after detecting that the tool spindle has reached the predetermined rotation speed and reached the constant speed rotation, the drive signal is sent to the work control means. It is possible.

[0064]

As described above, the present invention can provide a method and an apparatus capable of efficiently and accurately polishing an aspherical surface having a rotational axis asymmetric among free-form surfaces.

[Brief description of the drawings]

FIG. 1 is a front view of a polishing apparatus according to a first embodiment of the present invention.

FIG. 2 is a side view of FIG.

FIG. 3 is a front view of a polishing apparatus according to a second embodiment of the present invention.

FIG. 4 is a view showing a main part of a polishing apparatus according to a third embodiment of the present invention.

FIG. 5 is a view showing a main part of a polishing apparatus according to a fourth embodiment of the present invention.

FIG. 6 is an electrical block diagram according to the first and third embodiments.

FIG. 7 is a diagram showing a block configuration in a tool control unit in FIG. 6;

FIG. 8 is a diagram showing a block configuration in a work control unit in FIG. 6;

FIG. 9 is an electrical block diagram according to the second and fourth embodiments.

FIG. 10 is a diagram showing a block configuration in a tool control unit in FIG. 9;

11 is a diagram illustrating a block configuration in a work control unit in FIG. 9;

FIG. 12 is an explanatory diagram of polishing of an aspherical surface having an asymmetric rotation axis.

[Explanation of symbols]

 Reference Signs List 1 Polisher 9 Work 12 X-axis table (X-axis positioning mechanism) 13 Y-axis table (Y-axis positioning mechanism) 15 B-axis positioning mechanism 17 A-axis positioning mechanism 18 Work mounting table 19 Z-axis positioning mechanism 21 Spindle support (21A) , 21B) 22 spindle (22A, 22B) 23 tool (23A, 23B) 26 work rotation drive mechanism 87 tool spindle inclination control means 88 work rotation control means 90 Y-axis control means 91 X-axis control means 92 B-axis control means 93 A Axis control unit 94 Z-axis positioning unit 96 Work control unit (96A, 96B) 97 Tool control unit (97A, 97B) 120 Control circuit

Claims (6)

[Claims] 1. A work mounting table on which a work is placed is placed in a state where a tool tip is pressed against a work surface with a predetermined pressure.
In the method of polishing a free-form surface for polishing a work surface while controlling movement in an XY direction and an A direction around an axis parallel to the X axis, the work mounting table may be further polished in a B direction around an axis parallel to the Y axis. Is configured to be able to control the movement, and based on the processing data calculated from the work shape, the X,
The tool and the work are relatively positioned by controlling four directions of Y, A, and B directions, and the rotation axis of the tool or an arbitrary position of the tool surface in the normal direction at each processing point of the work. A method of polishing a free-form surface, wherein the polishing is performed by matching the parts. 2. A work mounting table on which a work is placed, with the tool tip pressed against the surface of the work with a predetermined pressure.
In a free-form surface polishing method for polishing a work surface while controlling movement in an XY direction and an A direction around an axis parallel to the X axis, a method for attaching a tool to a shaft end is provided, and tilting positioning with respect to a vertical axis is possible. A spindle, based on the machining data calculated from the workpiece shape,
The tool and the work are relatively positioned by controlling four directions of Y, A and a tilting movement direction of the spindle, and the rotation axis of the tool or the tool surface is set in a normal direction at each processing point of the work. A free-form surface polishing method, wherein the polishing is performed by matching an arbitrary part of the surface. 3. The work mounting table is rotatably mounted on an A positioning mechanism having an angle indexing function capable of moving in an A direction about an axis parallel to the X-axis. 3. The method for polishing a free-form surface according to claim 1, wherein the polishing is performed. 4. A work mounting table on which a work is placed, with the tool tip pressed against the work surface at a predetermined pressure,
In a free-form surface polishing apparatus for polishing a work surface while controlling movement in an XY direction and an A direction around an axis parallel to the X axis, an A axis having an angle indexing function for rotating and positioning around an axis parallel to the X axis. A positioning mechanism, a B-axis positioning mechanism having an angle indexing function of rotating and positioning about an axis parallel to the Y-axis, and a B-axis positioning mechanism and an A-axis positioning mechanism, which are disposed on a positioning mechanism located at an upper position. A work mounting table, and based on machining data calculated from a work shape, the tool and the work are formed by four mechanisms of the X-axis positioning mechanism, the Y-axis positioning mechanism, the B-axis positioning mechanism, and the A-axis positioning mechanism. Relative to each other, and in the normal direction at each processing point of the workpiece, the rotation axis of the spindle or any part of the tool surface Polishing machine with free-form surface for matching and polishing. 5. A work mounting table on which a work is placed, with the tool tip pressed against the work surface at a predetermined pressure,
In a free-form surface polishing apparatus for polishing a work surface while controlling movement in an XY direction and an A direction around an axis parallel to the X axis, an A axis having an angle indexing function for rotating and positioning around an axis parallel to the X axis. A positioning mechanism, a work mounting table arranged on the A-axis positioning mechanism, having an angle indexing function and controlling the rotation, and a spindle having means for mounting a tool to the shaft end and capable of tilting and positioning with respect to a vertical axis; Based on the processing data calculated from the work shape, the X,
The tool and the work are relatively positioned by controlling four directions of Y, A and a tilting movement direction of the spindle, and the rotation axis of the tool or the tool surface is set in a normal direction at each processing point of the work. A free-form surface polishing apparatus characterized in that polishing is performed by matching an arbitrary part of the surface. 6. The work mounting table is rotatably mounted on an A positioning mechanism having an angle indexing function capable of moving in an A direction about an axis parallel to the X axis. The free-form surface polishing apparatus according to claim 4, wherein the polishing is performed.