JP2003039282A - Free-form surface working device and free-form surface working method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a free-form surface working device and a free-form surface working method by which the shape of the worked three dimensional free-form surface can be measured accurately and in a short time without removing the work piece from the processing device and the correction of the worked three dimensional free-form surface can be executed accurately and in a short time, while the three dimensional free-from surface can be worked. SOLUTION: In the free-form surface working device, a feeding mechanism 2-8 for moving a working tool 9 with respect to a work piece 10 moves a shape measuring instrument 12 with respect to the work piece 10 so as to measure the free-form surface shape of the work piece 10. Therefore, the shape measuring instrument 12 is moved with respect to the work piece 10 by using the feeding mechanism 2-8 for a working tool without removing the work piece 10 from the working device 1, whereby the free-form surface shape of the worked surface of the work piece 10 can be measured accurately and in a short time. On the basis of the free-form surface shape accurately measured with the shape measuring instrument 12, correction working is executed again.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to, for example, a free-form surface processing apparatus and a free-form surface processing method for performing aspherical surface processing and free-form surface processing, and more particularly to an ultra-precision machine equipped with a non-contact three-dimensional shape measuring instrument. The present invention relates to a free-form surface processing device and a free-form surface processing method.

[0002]

2. Description of the Related Art In recent years, as a processing apparatus, an apparatus capable of processing with extremely high precision has been developed. In these processing devices, a fluid bearing is used for the rotating main shaft, a fluid bearing is also used for the blade feeding mechanism, or an extremely high precision rolling bearing is used, and a laser is used for measuring the feed amount of the feed system. It uses a long instrument.

As a result, it is not uncommon for these processing apparatuses to have an accuracy and resolution of the feed amount of about 0.01 micron. Using these processing devices, metal materials, glass, ceramics for molds, cemented carbides, etc. can be processed with submicron accuracy. Therefore, it becomes possible to directly grind or cut an optical element, which has conventionally been impossible to process without polishing.

Generally, these processing devices rotate a work piece fixed to a headstock and grind the work piece with a grindstone to form a spherical surface or an aspherical surface. In particular, in the case of a processing device that has a structure with a multi-axis feed shaft and is capable of grinding, not only the conventional rotationally symmetrical shape machining but also rotationally asymmetrical shape machining can be performed with high accuracy. It is possible to perform, and it is possible to perform processing of a shape (so-called free-form surface) that has not been considered in the past.

However, although these free-form curved surface processing devices can drive the processing main shaft and the feed shaft with extremely high accuracy, when the processing is performed by grinding, the grinding stone of the grinding wheel is removed along with the grinding processing. Wear is inevitable. Therefore, even if the grindstone is driven and controlled with high accuracy, the grindstone is worn out, and as a result, high-precision machining cannot be performed.

In the cutting process, the blades are still worn, and no matter how accurately the position of the feed carriage is controlled, the final positioning of the blades cannot be performed with high accuracy. Yes, after all, the final processed shape is
It does not reach the original accuracy of the feeding mechanism of the processing equipment.

In order to compensate for such a decrease in accuracy, conventionally, the work piece is removed from the processing device each time the work is performed, and the work piece is separately processed by a shape measuring device such as a high-precision three-dimensional measuring device. Was being measured. With this, the abrasion of the grindstone, the processing error caused by the positional deviation of the processing edge, etc. is obtained, and after estimating the processing amount required for the final processing shape, the workpiece is attached to the processing device again, The processing is repeated to obtain a desired processing accuracy of the work piece.

However, such a method requires more time for measurement, positioning, etc. than the actual machining time itself, leading to an increase in machining time and eventually machining cost.

[0009]

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to machine a three-dimensional free-form surface, and at the same time, to remove the shape of the machined three-dimensional free-form surface from the processing device. It is an object of the present invention to provide a free-form surface processing apparatus and a free-form surface processing method capable of accurately measuring in a short time and correcting a processed three-dimensional free-form surface accurately in a short time.

[0010]

In order to achieve the above object, a free-form surface machining apparatus of the present invention is a machine for machining a workpiece by moving a machining tool with respect to a workpiece by a feed mechanism. In the above, a shape measuring instrument for measuring the shape of the workpiece by moving the workpiece with the feed mechanism and measuring the distance between the workpiece and the workpiece is provided. Is characterized by.

According to the present invention, the feed mechanism for moving the processing tool with respect to the work piece moves the shape measuring instrument with respect to the work piece to measure the free curved surface shape of the work piece. Therefore, according to the present invention, by using the feed mechanism for the processing tool to move the shape measuring instrument with respect to the workpiece without removing the workpiece from the processing device,
The shape of the free curved surface of the work surface of the work piece can be accurately measured in a short time. Then, the correction processing can be performed again based on the free-form surface shape of the surface to be processed, which is accurately measured by this shape measuring instrument.

As described above, according to the present invention, it is not necessary to remove the workpiece from the processing apparatus, it is not necessary to measure the shape of the workpiece using a separately expensive measuring apparatus, and the workpiece is processed again by the processing apparatus. There is no need to attach a work piece and perform processing. Further, for that reason, a processing error due to an installation error can be eliminated in principle, and processing accuracy can be improved, shape measurement accuracy can be improved, measurement time can be shortened, and the cost of the processing apparatus can be reduced.

Further, the free-form surface processing apparatus of one embodiment is
The feed mechanism is an ultra-precision feed mechanism, and the position of the measuring instrument is corrected by the ultra-precision feed mechanism.

In this embodiment, since the feeding mechanism is an ultra-precision feeding mechanism, precise position correction of the measuring instrument can be performed with an accuracy of the order of submicron.

Further, the free-form surface processing apparatus of one embodiment is
The feed mechanism has at least the X-axis direction, the Y-axis direction orthogonal to the X-axis, the Z-axis direction orthogonal to the X-axis and the Y-axis, and the rotation direction around the X-axis. In a certain A direction and in the B direction which is the rotation direction around the Y axis,
The shape measuring device is controllable, and is a non-contact shape measuring device that measures the shape of the work without contacting the work, and the non-contact measuring device uses the feeding mechanism. Accordingly, the workpiece is moved with respect to the workpiece, the shape of the workpiece is measured, and the position is corrected by the feeding mechanism.

In this embodiment, the feed mechanism can control the feed direction in the X-axis, Y-axis, Z-axis, A-axis, and B-axis directions. Therefore, by controlling the feed direction of each axis when measuring the shape of the surface to be processed of the work piece, the non-contact shape measuring instrument can be placed in the most suitable posture for the most accurate measurement.

Further, in the free-form surface processing apparatus of one embodiment, when the feed mechanism uses the shape measuring instrument to measure the shape of the workpiece, the posture of the shape measuring instrument is changed to the workpiece. The angle of the shape measuring instrument is corrected so as to maintain a predetermined angle with the normal to the measurement site on the surface to be processed.

In this embodiment, when the shape measuring instrument measures the shape of the workpiece, the posture of the shape measuring instrument is set to be a predetermined line with the normal line of the measurement site of the workpiece surface of the workpiece. The feed mechanism corrects the angle of the shape measuring instrument so as to maintain the angle.

Thus, no matter what the free-form surface of the workpiece is, the angle of the shape measuring instrument is set so as to maintain a predetermined angle with the normal to the processing point of the workpiece. Corrections can be made. Therefore, it is possible to eliminate an error factor in shape measurement due to the inclination of the surface of the workpiece to be measured, and it is possible to perform highly accurate three-dimensional shape measurement.

Further, in the free-form surface processing apparatus of one embodiment, the feed mechanism is configured such that the attitude of the processing tool with respect to the surface to be processed of the workpiece is equal to the normal line of the processing portion of the surface to be processed during processing. The workpiece is machined by the machining tool while correcting the angle of the machining tool so as to maintain a predetermined angle, and at the time of shape measurement, the measurement posture of the shape measuring instrument with respect to the surface to be machined is the above-mentioned. The shape measuring instrument measures the machining point of the surface to be machined while the angle of the shape measuring machine is corrected so as to maintain a predetermined angle with the normal to the machining point on the surface to be machined.

In this embodiment, the feed mechanism is configured such that, during machining, the posture of the machining tool with respect to the surface of the workpiece to be machined maintains a predetermined angle with the normal to the machined portion of the machined surface. While performing the angle correction of the above processing tool,
The workpiece is processed by the processing tool. Also,
At the time of shape measurement, the shape measurement is performed while performing the angle correction of the shape measurement device so that the measurement posture of the shape measurement device with respect to the work surface maintains a predetermined angle with the normal line of the processing point of the work surface. The processing point of the surface to be processed is measured by a tool.

Therefore, in this embodiment, at the time of machining, the machining can be performed at one point (same position) of the machining tool, and at the time of measuring the shape, the angle of the shape measuring instrument is corrected and the measured object is measured. The shape measurement error factor due to the inclination of the surface can be eliminated.

Further, in the free-form curved surface machining apparatus of one embodiment, during the machining, the feed mechanism determines a machining posture of the machining tool with respect to a surface of the workpiece to be machined, and a normal line of a machining point of the surface to be machined. While the angle of the machining tool is being corrected so that the specified angle is maintained, the machining tool is sent while
At the time of shape measurement, the shape of the shape measuring instrument is corrected while the posture of the shape measuring instrument is maintained at a predetermined angle with respect to the surface to be processed of the workpiece and the normal to the measurement site. The shape measuring instrument is sent so that the measuring instrument traces a trajectory substantially the same as the machining trajectory of the workpiece by the machining tool.

In this embodiment, the feed mechanism feeds the shape measuring device so as to trace a locus approximately the same as the machining locus of the machining tool. Therefore, it can be seen that the distance data between the workpiece and the workpiece measured by this shape measuring instrument has a small variation and is substantially constant, and the portion having the variation in the distance data is the portion where the machining needs to be corrected. Therefore, the correction processing can be performed pinpoint only at the portion where the processing correction is required, and the processing time and the shape measurement time can be significantly reduced.

Further, in the free-form surface processing apparatus of one embodiment, the shape measuring instrument is a shape measuring instrument that measures the shape of the workpiece by using laser light.

In this embodiment, since the shape measuring instrument measures the shape of the work piece by using the laser beam, the free curved surface shape of the work piece can be obtained in a non-contact manner with respect to the work piece. It becomes possible to measure. In addition, the measurement posture (position) of the shape measuring instrument (sensor) with respect to the surface to be processed is measured while performing the angle correction of the shape measuring instrument so that the measurement posture (position) always maintains a predetermined angle with the normal to the processing point on the surface to be processed. By doing so, the measurement error factor due to the inclination of the surface to be processed can be eliminated, and highly accurate non-contact three-dimensional shape measurement can be performed.

Further, in the free-form curved surface machining apparatus of one embodiment, the feed mechanism includes a feed locus for moving the machining tool when the machining tool is machining the surface of the workpiece to be machined, and a machining trajectory during machining. On the basis of the information on the angle correction of the machining tool, the shape measuring instrument is moved to correct the angle of the shape measuring instrument.

In this embodiment, the movement and angle correction of the shape measuring instrument at the time of shape measurement are performed based on the feed trajectory for moving the processing tool and the information on the angle correction of the processing tool at the time of processing. The shape measuring instrument can be traced along the trajectory of the processing tool during processing, and the shape measuring time can be shortened.

Further, when the shape measuring instrument uses a laser beam, tracing is performed according to the locus of the processing tool at the time of processing, so that the focus deviation of the sensor portion becomes very small and the shape measuring time is shortened. it can.

Further, the free-form surface processing apparatus of one embodiment is
The feed mechanism, the feed is controlled by a program or data for numerical control, based on the data measured by the shape measuring instrument of the shape of the work surface of the workpiece, based on the data measured by the processing tool A program or numerical control data for controlling the feed of the processing tool when processing the surface to be processed is corrected.

In this embodiment, the machining when the machining tool processes the work surface of the work based on the data obtained by the shape measuring device measuring the shape of the work surface of the work. Correct the program that controls the tool feed or the data for numerical control. As a result, the surface to be processed of the workpiece can be easily and accurately corrected.

Further, the free-form surface processing apparatus of one embodiment is
The shape measuring instrument is mounted on a tool base that supports the machining tool.

In this embodiment, since the shape measuring instrument is mounted on the tool base that supports the machining tool,
It is possible to correct the angle of the shape measuring instrument during shape measurement based on the angle correction information of the processing tool during machining, and it is easy to move the shape measuring instrument along the trajectory of the machining tool during machining. The shape measurement time can be shortened.

Further, in the free-form curved surface processing apparatus of one embodiment, the shape measuring instrument is mounted on the tool stand facing 180 ° opposite to the processing tool.

In this embodiment, since the shape measuring instrument is mounted on the tool stand facing 180 ° opposite to the machining tool, the shape measuring instrument is ejected from the machining tool during machining. It is possible to prevent these from adhering to the shape measuring instrument, which is kept away from the processing dust scattered by cooling air, oil, etc.

The free-form surface processing method of one embodiment is
A free-form surface processing device that moves a processing tool with an ultra-precision feed mechanism to process a workpiece, and moves a non-contact three-dimensional shape measuring instrument with the ultra-precision feed mechanism to measure the shape of the workpiece. According to a machining program, the ultra-precision feed mechanism is characterized in that the X-axis, Y-axis, and Z-axis directions orthogonal to each other, the A-direction around the X-axis, and the B-direction around the Y-axis. The feed can be controlled in any direction, and when measuring the shape of the workpiece, the attitude of the non-contact three-dimensional shape measuring instrument is adjusted by the ultra-precision feed mechanism based on the machining program. The three-dimensional shape of the workpiece is moved by moving the non-contact three-dimensional shape measuring instrument while correcting the angle of the non-contact three-dimensional shape measuring instrument so as to maintain a predetermined angle with the normal line of the measurement site. Measurement is performed and based on this 3D shape measurement data There are, to modify the machining program, the ultra-precision feed mechanism, in accordance with the corrected machining program, by moving the machining tool, machining the workpiece.

In this embodiment, when measuring the shape of the work piece, the ultra-precision feed mechanism moves the non-contact three-dimensional shape measuring device based on the processing program to make the three-dimensional shape of the work piece. Take a measurement. This machining program is a feed control program that causes the ultra-precision feed mechanism to move the machining tool when machining the workpiece with the machining tool.

Therefore, according to this embodiment, the non-contact three-dimensional shape measuring instrument can be moved along the same trajectory as the trajectory of the machining tool during machining. Therefore,
From the three-dimensional shape measurement data of this non-contact three-dimensional shape measuring instrument, the amount (error) in which the actual machining shape deviates from the target shape by the above machining program can be immediately obtained. Then, based on the three-dimensional shape measurement data, the machining program is modified so as to compensate for the error.
As a result, it is possible to perform pinpoint correction processing only on a portion that requires processing correction, and it is possible to greatly reduce processing time and shape measurement time.

The free-form surface processing method of one embodiment is
A free-form surface machining method using a free-form surface machining device having an ultra-precision feed mechanism, wherein the machining tool traces a locus that is substantially the same as the locus when the workpiece is machined. By moving the measuring instrument and measuring the shape of the workpiece with the shape measuring instrument, the wear amount of the processing tool during the processing is measured, and based on the measured wear amount, the ultraprecision A machining program for controlling the feed of the machining tool by the feed mechanism or a numerical control data for controlling the feed of the machining tool by the ultra-precision feed mechanism is corrected.

In this embodiment, the above-mentioned shape measuring instrument is moved by the ultra-precision feed mechanism so that the machining tool traces a locus that is substantially the same as the locus when the workpiece is machined.
The shape measuring device measures the shape of the workpiece. Based on the measured shape (data), the wear amount of the working tool during the working is measured. Then, the measured wear amount can be immediately reflected in the wear correction program (numerical control data) of the machining program. Therefore, it is possible to easily correct the feed by the feed mechanism in response to the wear of the machining tool which is a factor of the machining shape error.

[0041]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will now be described in detail based on the illustrated embodiments.

FIG. 1 shows a side view of a free-form surface processing apparatus 1 according to an embodiment of the present invention.

This free-form surface processing apparatus 1 is provided with a Z stage 3, an X stage 5, a B stage 6, a Y stage 7 and a tool base 8 on a base 2, which are of nano-order necessary for processing and measurement. Ultra-precision feed is possible.

The Z stage 3 is movable along the upper surface of the base 2 in a substantially horizontal Z direction (left and right directions in the drawing), and a headstock 4 is mounted on the Z stage 3. ing. The headstock 4 has a main shaft 4a whose center axis is the Z-direction axis, and the main shaft 4a is rotated about the center axis as a rotation center axis. Also, this spindle 4a
Is the chucking of the headstock 4 and the workpiece 10
Is fixed. For example, when processing a rotationally symmetrical shape on the workpiece 10, the main shaft 4a is rotated to perform the processing. Further, when the workpiece 10 is processed to have a rotationally asymmetric shape, the processing is performed without rotating the spindle 4a.

On the other hand, the X stage 5 is placed on the base 2 at a predetermined distance from the Z stage 3 in the Z direction.
Is installed. The X stage 5 is movable in a direction orthogonal to the Z direction and in an X direction substantially parallel to the upper surface of the base 2. The B stage 6 is mounted on the X stage 5. The B stage 6 is rotatable in the B direction with the central axis in the Y direction perpendicular to both the Z direction and the X direction as the central axis of rotation.

A Y stage 7 movable in the Y direction is mounted on the B stage 6.

The Y stage 7 also has a tool base 8
Is attached. The tool base 8 is rotatable with respect to the Y stage 7 in the A direction around the rotation axis extending in the X direction from the point P in the drawing.

The Z stage 3, the main shaft 4a, the X stage 5, the B stage, the Y stage 7 and the tool base 8 constitute an ultra-precision feed mechanism, and use a rolling bearing or a static pressure bearing, and are of the order of 0.01 μm. The movement accuracy is secured.

The tool base 8 is provided with a tool portion 11 having a grindstone 9 for processing the workpiece 10 and a sensor portion 12 for measuring the workpiece 10. This tool part 11
Can rotate the rotating shaft 11a to rotate the grindstone 9.

The tool base 8 is rotated in the A direction around the rotation axis passing through the P point, whereby the sensor unit 12 is rotated.
Can be positioned at a shape measuring position facing the workpiece 10. The sensor unit 12 has an objective lens 13, and the objective lens 13 collects a laser beam on the workpiece 10 and measures the distance between the workpiece 10 and the workpiece 10 to perform shape measurement. To do.

The X stage 5, Y stage 7, Z stage 3, B stage 6, and tool base 8 mounted on the base 2 are driven by their own servo motors, and each servo motor is computer controlled. It is controlled by the control signal of the control device. In this free-form surface processing device 1, these X, Y, Z, B
By the movement operation of the stage and the tool base 8, the rotation of the spindle 4a, and the rotation of the grindstone 9, the workpiece 10 can be processed into a free curved surface shape.

Next, a method of processing the surface of the workpiece 10 into a free curved surface by the free curved surface processing apparatus of this embodiment will be described.

FIG. 2 shows a desired free-form surface 1
An example of a workpiece 10 having 0a is shown. The surface 10a of the workpiece 10 has an aspherical shape, and the aspherical shape in the X-direction section and the aspherical shape in the Y-direction section in FIG. 2 have different shapes.

When machining the rotationally asymmetric surface 10a of the workpiece 10 as described above, by driving the Z stage 3 and the X stage 5 without rotating the main shaft,
By moving the grindstone 9 relative to the workpiece 10 from the end of the workpiece 10 to an aspherical shape in the X direction, the workpiece 1
Then, the Y stage 7 is moved by one step in the Y-axis direction, and similarly, the grindstone 9 is moved in the aspherical shape in the X direction relative to the workpiece 10. Grind. By repeating this, as shown in FIG. 2, it is possible to obtain the workpiece 10 in which the surface 10a is processed into a free curved surface shape.

Next, the angle correction of the grindstone 9 in this embodiment will be described with reference to FIG.

FIG. 3 shows a state in which the workpiece 10 processed into a free-form surface is viewed in the Y direction. The rotating shaft 11a of the tool portion 11 is rotated to rotate the grindstone 9 attached to the rotating shaft 11a. While rotating around the axis 11a, a state is shown in which the grindstone 9 is working from the end of the workpiece 10 into an aspherical shape in the X direction. In FIG. 3, the state drawn by the broken line shows the posture of the grindstone 9 in the state where the processing has progressed from the state drawn by the solid line.

As shown in FIG. 3, first, by driving the Z stage 3 and the X stage 5 from the end of the workpiece 10, the grindstone 9 is moved along the aspherical locus in the X direction. The workpiece 10 is moved relative to the workpiece 10, and the workpiece 10 is ground. As the grindstone 9 is driven by the processing in the X direction, the normal line of the surface at the processing point where the grindstone 9 processes the workpiece 10 sequentially changes. In order to keep the grindstone 9 at a constant angle with respect to this normal, the B stage 6
By driving (rotating) the B stage 6 in the B direction, the angle (posture) of the grindstone 9 with respect to the workpiece 10
Correction control. As a result, the workpiece 10 is always processed with only one point of the grindstone 9.

Here, the free-form surface processing apparatus 1 is previously provided, for example, inside the drive system of the super-feed mechanism in advance.
Since the final machining shape of the workpiece 10 is held as program data, when the grindstone 9 moves to a certain machining point, the correction amount of the angle (posture) of the grindstone 9 at the machining point is the above program. It is immediately determined based on the data, and here, the moving amount of the B stage 6 in the B direction is determined.

Then, the Y stage 6 is moved in the Y axis direction by one step, and the grindstone 9 is moved from the end of the workpiece 10 along the aspherical locus in the X direction in the same manner as described above. The workpiece 10 is moved relative to the workpiece 10 to grind the workpiece 10. With the movement of one step in the Y-axis direction, the normal line of the processing point of the grindstone 9 changes by one step in the A direction.

The tool base 8 is driven to adjust the position of the grindstone 9 in the B direction so that a constant angle is always maintained with respect to the normal line after moving by one step in the A direction. , The position of the B stage 6 in the B direction is adjusted so that the grindstone 9 always keeps a constant angle with respect to the normal line of the machining point, which changes sequentially with the machining in the X direction. By controlling, the processing is always performed with only one point of the grindstone 9.

Also in this case, the free curved surface processing apparatus 1
Program data representing a machining shape is held in advance inside, and the control amount (correction amount) of the angle of the grindstone 9 is immediately determined by the program data.

By repeating the control of the angle (posture) of the grindstone 9 as described above, the work piece 10 can be machined with only one point of the grindstone 9 at all times, and the wear of the grindstone 9 is compensated. It will be easier.

As described above, not only when the grindstone 9 is rotated for machining, but also when cutting with a cutting tool or the like as a working tool, the cutting tool or the like is used to cut the work surface of the workpiece 10. In order to maintain a constant angle with respect to the normal of the machining point on the machining surface, the five axes (Z, X, Y,
While correcting the tool angle by (B, A direction) control,
It can be cut.

Next, the shape measurement in the free-form surface processing apparatus 1 will be described.

After the processing of the workpiece 10 is completed based on the above processing procedure, the shape of the workpiece 10 is measured using the sensor section 12. This shape measurement is performed on the processed surface 10a of the processed object 10 formed by the above-described processing.
This is performed in order to measure the amount (error) of the shape deviated from the target shape.

No matter how precisely the rotary spindle 4a, the driven X stage 5, Y stage 7, Z stage 3, B stage 6 and tool base 11 are controlled, the grindstone 9
It is impossible to completely eliminate the error in the machined shape due to wear of the tool, feed error, etc.

FIG. 4 shows how the shape of the workpiece 10 is measured. A sensor unit 12 installed on the tool base 8 in order to measure the three-dimensional shape of the surface of the workpiece 10 that has been ground into a free-form surface by the rotation of the grindstone 9 without contact.
To use. This sensor unit 12 is, as shown in FIG.
Since the tool base 8 is located on the opposite side of the rotation about the rotation axis passing through the point P by about 180 °, the sensor unit 12 is rotated by about 180 ° around the rotation axis (direction A). Can be located at the shape measuring position.

The sensor section 12 is a laser displacement meter, and the objective lens 13 focuses the laser light on the workpiece 10 to detect the focal position of the laser light reflected from the workpiece 10. The shape of the workpiece 10 is measured by measuring the distance to the workpiece 10.

The principle of the laser displacement meter is that a pinhole is provided near the light receiving element, and when the workpiece 10 is at the focus position, the laser light reflected at the focus position reaches the light receiving element through the pinhole. However, when the workpiece 10 is not at the focal position, the reflected laser light can hardly pass through the pinhole and does not reach the light receiving element.

The sensor section 12 uses a laser focus displacement meter to which this principle is applied. Alternatively, the sensor unit 12 uses a CCD as a light receiving element, and the laser light reflected at the focal position is condensed at one point of the CCD.
Since the reflected laser light is not focused on one point of the CCD at a position other than the focus position, the focusing lens is moved to obtain the focusing position, and the distance from the moving distance of the focusing lens to the workpiece 10 is calculated. The measurement principle may be applied to perform highly accurate measurement.

As described above, when the sensor section 12 for measuring the distance using the laser beam is used, the sensor section 12 can be made compact and the sensor section 12 can be easily mounted on the tool base 8.

However, in the case of the measuring method in which the distance is measured by the laser as described above, when the normal line of the measuring surface of the workpiece 10 is inclined with respect to the optical axis of the laser, the laser from the measuring surface is measured. However, there is a drawback that the reflected light of does not correctly pass through the optical axis of the optical system. Further, when the inclination of the measurement surface changes (changes) within the range of the focused beam diameter, the measurement error becomes large and it becomes impossible to perform ultraprecision measurement on the order of nanometers.

Therefore, in this embodiment, the sensor is driven by driving the tool base 8 in the direction A so that the reflected light from the measurement surface of the workpiece 10 always passes correctly on the optical axis of the optical system. The angle of the part 12 is controlled. That is, while correcting the angle of the sensor unit 12 with respect to the measurement surface of the workpiece 10 so that the measurement posture (optical axis) of the sensor unit 12 always maintains a constant angle with the normal line of the measurement point of the workpiece surface 10a,
The distance between the workpiece 10 and the surface 10a to be processed is measured. For this angle correction, X stage 5, Y stage 7, Z
The ultra-precision feed mechanism including the stage 3, the B stage 6 and the tool base 8 is drive-controlled. In this way, by driving the ultra-precision feeding mechanism so that the optical axis of the sensor unit 12 to be measured and the normal line of the processing surface of the workpiece 10 are kept at a constant angle, the distance can be increased by the laser. The error in the measurement of can be kept extremely small.

For example, FIG. 2 shows a workpiece 10 having a surface 10a to be processed into a free-form surface shape, and in FIG. 2, a cross section in the X-Z plane including the X-axis and the Z-axis is shown. The aspherical shape is different from the Y-direction cross section. The X-direction cross section is a cross section obtained by cutting the workpiece 10 along the XZ plane including the X axis and the Z axis, and the Y direction cross section is the YZ including the Y axis and the Z axis. The work piece 10 in a plane
It is the cross section cut.

The workpiece 10 having such a rotationally asymmetrical shape
When measuring the shape of the surface 10a to be processed, the sensor unit 12 is made to have an aspherical shape in the X direction from the end of the object 10 relative to the object 10 as in the case of processing. It is moved and the shape of the surface 10a to be processed is measured.

Next, the Y stage 7 is moved in the Y axis direction by one step, and then the sensor unit 12 is moved to the aspherical shape in the X direction relative to the workpiece 10. The shape of the work surface 10a is measured. By repeating this, the shape of the processed surface 10a of the processed object 10 processed into the free curved surface shape is measured.

Next, the angle correction of the sensor section 12 will be described with reference to FIG.

FIG. 4 shows a state in which the workpiece 10 in which the surface 10a to be processed is processed into a free-form surface is viewed from the Y direction. In FIG. 4, the X stage 5 is driven so that the sensor unit 1 is changed from the end of the workpiece 10 to the aspherical shape in the X direction.
2 shows a state in which 2 is moved to measure the aspherical shape in the X direction of the processed surface 10a of the processed object 10.

In FIG. 4, the sensor section 1 drawn by the broken line
2 shows the position and orientation of the sensor unit 12 in a state where the shape measurement has proceeded from the position of the sensor unit 12 drawn by the solid line. The posture (angle) with respect to the workpiece 10 of the sensor unit 12 in this state is corrected.

First, the sensor portion 12 is relatively moved from the end portion of the workpiece 10 to the aspherical shape in the X direction, and the shape of the workpiece surface 10a of the workpiece 10 is measured. Along with this shape measurement in the X direction, the normal line of the measurement point on the surface to be processed 10a changes sequentially. For this normal, the sensor unit 1
The B stage 6 is driven so that the optical axis from 2 always maintains a constant angle, the attitude of the sensor unit 12 is adjusted in the B direction, and the optical axis from the sensor unit 12 is angularly controlled in the B direction. .

As a result, the laser light emitted from the sensor section 12 and the reflected light reflected at the measuring point on the surface 10a to be processed always make the optical axis of the optical system correct.

Next, the Y stage 7 is moved in the Y axis direction by one step, and the sensor unit 12 is moved in the same manner as described above.
Is relatively moved from the end of the workpiece 10 to the aspherical shape in the X direction, and the shape of the surface 10a to be processed is measured. With the movement of the sensor unit 12 in the Y-axis direction by one step, the normal line of the processing point on the surface to be processed 10a changes by one step in the A direction.

[0083] In this free-form surface machining apparatus, a control system for controlling the driving of the ultra-precision feed mechanism, or to process previously to any free curved surface of the workpiece 10 has a program called. Therefore, in the control system, if the program (machining data) and the machining position (position of the grindstone 9 (or blade)) are known as the machining position moves, the normal direction of the surface to be machined at the machining position can be determined. Whether such a value will be calculated immediately.

Therefore, according to the control system, with respect to the normal line at the measurement point (laser arrival point) of the workpiece 10 after the sensor section 12 has moved one step in the Y direction,
The tool base 8 can be driven to move the sensor unit 12 in the A direction so that the optical axis of the laser light from the sensor unit 12 always maintains a constant angle.

Further, with the shape measurement in the X direction,
By driving the B stage 6 and moving the sensor unit 12 in the B direction with respect to the normal line of the measurement point that changes sequentially, the optical axis of the sensor unit 12 is always at a constant angle with respect to the normal line. The posture (angle) of the sensor unit 12 can be controlled so that At this time, if the Z stage 3 is driven to move the workpiece 10 forward, the distance between the workpiece 10 and the objective lens 13 can be kept constant as shown in FIG.

As a result, the reflected light, which is the laser light from the sensor section 12 reflected at the measurement point, can always pass correctly on the optical axis of the optical system.

By repeating the above-described operation, the distance measurement by the laser beam from the sensor section 12 is continued while keeping the state where the reflected light from the measurement point of the workpiece 10 correctly passes on the optical axis of the optical system. It becomes possible. Then, the error due to the incident angle of the light ray as described above can be made extremely small, and high-precision measurement on the order of nanometers becomes possible.

Strictly speaking, since the inclination of the machined surface is not the shape of the final object during the machining of the workpiece 10, it is calculated from the data representing the machined shape held by this machining apparatus. The angle is different from the tilt angle. However, in the machining process targeted by this embodiment, the machining amount (removal amount) of the workpiece 10 itself is a submicron-order machining process, and in this case, the deviation of the surface inclination from the final shape is extremely small. Therefore, the sensor unit 12, which is a shape measuring instrument, does not reach an amount enough to cause an error, and accurate measurement can be performed.

Here, when processing the free-form surface, the tool portion 11 is always maintained at a constant angle with respect to the normal line of the processing point. Therefore, this processing device
The normal direction is calculated beforehand during processing, and the tool part 1
It has a function of correcting the angle of 1 (grinding stone 9). Therefore, when measuring the shape of the free-form surface so that the sensor unit 12 always maintains a constant angle with respect to the normal line of the measurement point, the angle correction information of the tool unit 11 at the time of machining is used as a basis. Thus, the angle of the sensor unit 12 can be corrected when measuring the shape. In this case, it is not necessary to newly calculate angle correction data at the time of measuring the shape, and the measurement efficiency is significantly improved. In addition, it is possible to shorten the measurement time of the three-dimensional shape.

By the way, in order to correct the angle of the sensor unit 12 at the time of shape measurement based on the angle correction information of the tool unit 11 at the time of processing, first, the tool unit 11 and the sensor unit 12
It is necessary that the position relationship with is clear. this is,
In the case of a measuring instrument using light, the measurement dynamic range of the sensor unit 12 is approximately several tens to several hundreds of microns, and it is necessary to perform shape measurement within this dynamic range, and This is because the optical axis and the direction of the grindstone 9 may not always match.

Therefore, according to this embodiment, the grindstone 9 is brought into contact with the work piece 10 when the work piece is processed, and the work piece 1 is processed.
Add a tool mark to 0. At this time, the position and orientation data of the ultra-precision feed mechanism including the tool base 8 is stored in the control system, for example.

Next, the ultra-precision feeding mechanism is driven to make the objective lens 13 of the sensor section 12 face the workpiece 10, and the position and orientation of the sensor section 12 are set as follows.
The laser light from the sensor unit 12 is adjusted to the tool mark by the objective lens 13 by adjusting the ultra-precision feeding mechanism.
Focus with and focus on this tool mark. Furthermore, so that the reflected light of the laser light at the location of this tool mark passes correctly through the center of the optical axis of the optical system,
The position and orientation of the sensor unit 12 are adjusted by the above ultra-precision feeding mechanism. Then, the position and orientation data of the ultra-precision feed mechanism at this time is stored in the control system. The difference between the above two sets of position and orientation data represents the positional relationship between the tool unit 11 and the sensor unit 12.

Further, the whetstone 9 which is the processing tool of the free-form surface processing apparatus 1 and the sensor section 12 which is the shape measuring instrument thereof can be calibrated by the following method.

First, the calibration for the shape measurement of the sensor section 12 is performed. In this, the sample (workpiece) is processed into a spherical shape by the grindstone 9, and the shape is measured by the sensor unit 12. Next, the spherical shape of this actually processed sample is
The sensor unit 12, which is a shape measuring instrument, is calibrated so that the shape measured by the optical interferometer and the shape measured by the sensor unit 12 coincide with each other.

In this embodiment, since processing and shape measurement are performed on the same stage having nanometer position control accuracy, there is substantially no error in processing and shape measurement due to the accuracy of each stage.

Next, the position of the sensor unit 12, which is the shape measuring instrument, with respect to the position of the grindstone 9, which is the processing tool, is calibrated. That is, as described above, the grindstone 9 is brought into contact with the workpiece 10 and moved in the X and Y directions, and the laser light from the sensor 12 is collected by the objective lens 13 at the intersection of the generated tool marks. Make it illuminate and focus at the intersection of the tool marks. Then, the ultra-precision feeding device is adjusted so that the reflected light of the laser light can correctly pass through the optical axis center of the optical system.

Then, the machine coordinates of the ultra-precision feeding device, which represents the intersection point position of the tool mark at the time of machining, and the machine coordinates of the intersection point position of the tool mark measured by the sensor unit 12, are set, for example, in the control system. Ask by. Then, using these two machine coordinates as offset values, the machine coordinates of the ultra-precision feeding device are corrected between the time of processing and the time of shape measurement. With this correction, the machine coordinates of the ultra-precision feed device can be calibrated so that the locus of the machining point of the grindstone 9 that is moved during machining matches the locus of the measurement point of the sensor unit 12 that is moved during measurement. .

As described above, according to this embodiment, since the position of the sensor portion 12 with respect to the grindstone 9 can be calibrated by the processing apparatus itself, it is possible to eliminate an error due to a change with time of the processing apparatus. Moreover, the rotation mechanism of the tool base 8 can be made into a simple structure.

By calibrating the sensor portion 12 as the shape measuring device as described above, the surface of the workpiece 10a of the workpiece 10 is measured based on the data measured by the sensor portion 12, and the surface of the workpiece 10 is processed. It is possible to feed back the processing correction information for executing the correction processing for making the target processing shape of 10a to a preset target processing shape to the ultra-precision feeding device.

In this embodiment, regarding the positional relationship between the tool section 11 and the sensor section 12, the tool section 11 and the sensor section 12 are arranged on the same tool base 8. If the positional relationship between the tool unit 11 and the sensor unit 12 is clear, the movement of each stage (each axis) at the time of measurement is based on the movement information of each stage (each axis) of the ultra-precision feed mechanism during processing. By correcting the information, each stage of the ultra-precision feeding mechanism can be controlled so that the measurement point of the sensor unit 12 moves along the locus of the processing point processed by the tool unit 11. Therefore, by disposing the tool unit 11 and the sensor unit 12 on the same tool base 8, it becomes easy to correct the movement information of each stage (each axis).

Also, in this embodiment, the sensor unit 12
With respect to the rotation center point P in the A direction,
It was placed on the opposite side of 80 °. As a result, at the time of processing with the grindstone 9, the heat generated by the processing is cooled by air, oil, or the like, and when the processing waste is being discharged, the processing waste can be prevented from adhering to the sensor unit 12.

In the above embodiment, the following method is available as a method for acquiring the shape measurement data. In this method, the sensor unit 12 is moved along the same locus as the locus of the grindstone 9 according to the program data for machining the target free-form surface, and the shape of the work surface 10a is measured. From the amount of change in the value measured by this shape measurement, it is possible to determine how much the actually processed free-form surface has an error with respect to the target free-form surface. If this error information is measured for all tool trajectories during processing, the surface 10a to be processed can be measured with extremely high precision in a three-dimensional shape.

Actually, by measuring the above-mentioned error information with respect to the tool locus every several steps during machining,
The shape can be measured with sufficiently high accuracy.

Originally, the X stage 5, the Y stage 7, the Z stage 3, the B stage 6, and the tool base 8 which compose the above-mentioned ultra-precision feed mechanism are ensured to have nanometer precision. Work surface 1 based on the mechanism
By measuring the shape of 0a, the shape can be measured extremely accurately, and it is not necessary to separately prepare a measuring device.

The above-mentioned first shape measuring method is a method in which the scanning locus of the sensor unit 12 is made to coincide with the machining locus of the grindstone 9 as a machining tool, and the distance measurement amount by the sensor unit 12 at that time is read. . With this method, the distance measurement amount by the sensor unit 12 matches the deviation amount from the target machining shape, and the amount of deviation from the target machining shape is determined by the data (distance measurement amount) from the sensor unit 12. It has the advantage of being immediately noticeable. Further, since the control system for driving the sensor unit 12 can be the same as the control system for performing the machining, there is an advantage that the control mechanism and the control method are simple.

Further, in the above embodiment, the following second method can be considered as a procedure for measuring the shape. The second shape measuring method is a method of scanning the sensor unit 12 so that the distance measurement amount by the sensor unit 12 is always zero.

Specifically, in this shape measuring method, the sensor section 12 is arranged so that the measurement point of the sensor section 12 is located on the contour of the target processed shape. At this time, if the distance measurement amount output by the sensor unit 12 is zero, the target processed shape and the actual processed shape match at this measurement point. On the other hand, if the distance measurement amount is positive, the actual machined shape is farther than the target machined shape in the direction normal to the measuring point, that is, over-grinding. On the contrary, if the distance measurement amount is negative, the actual machined shape is closer to the target machined shape in the normal direction of the measurement point, that is, the grinding is insufficient.

A zero point at which the output (distance measurement amount) of the sensor unit 12 becomes zero when the sensor unit 12 itself is moved by the ultra-precision feeding mechanism when the distance measurement amount is positive or negative. Are always matched with the actual surface of the workpiece 10. The shape of the workpiece surface 10a of the workpiece 10 can be obtained from the movement amount of the ultra-precision feed mechanism at each measurement point. According to this shape measuring method, the control system for driving the sensor unit 12 becomes complicated, while the sensor unit 12 always operates near the zero point of its output.
There is an advantage that the linearity with respect to the measurement amount of the sensor unit 12 is unnecessary. That is, with this shape measuring method, it is only necessary to determine whether the distance measurement amount output by the sensor unit 12 is zero, positive, or negative. This means that when the sensor unit 12 as the shape measuring instrument is mounted on the feeding mechanism of the processing apparatus as in this embodiment,
This is a huge advantage. Because the sensor unit 12
This is because it is sufficient to determine whether the output value is zero, positive or negative, and the sensor unit 12 can be obtained at low cost. In addition, the sensor unit 12 itself is moved by the ultra-precision feed mechanism that moves the tool unit 11 as a processing tool to measure the shape of the surface 10a to be processed of the workpiece 10, so equipment for measuring the shape is provided. Almost no investment required.

According to this second shape measuring method,
The amount of error with respect to the target machining shape specified by the machining program becomes the shape error represented by the amount of movement by the ultra-precision feed mechanism. From the shape error represented by the amount of movement by the ultra-precision feed mechanism, the machining program can be modified, and only the location of the workpiece 10 that requires machining modification can be pinpointed. Therefore, the tool unit 11
Can be quickly moved to a correction processing point by the ultra-precision feed mechanism, and the processing time can be greatly shortened.

Further, according to the free-form surface processing apparatus of this embodiment, it is possible to dynamically track the wear amount of the processing tool (grinding stone 9). That is, the error of the actually processed shape with respect to the target processed shape designated by the processing program, that is, the shape error mainly occurs due to the abrasion of the grindstone 9. Therefore, the shape error tends to gradually increase with the processing. Therefore, the grindstone 9 during this processing
The wear amount of the grindstone 9 can be grasped by tracing the same locus as that of No. 2 by the sensor unit 12 and sequentially tracing the amount of shape error. Then, by correcting the feed of the grindstone 9 according to the amount of wear, it becomes possible to form a free-form surface with few shape errors. Further, this also makes it possible to accurately predict the wear amount of the processing tool (grinding stone 9).
It is also possible to incorporate the predicted wear amount in advance and perform the machining while correcting the feed by the predicted wear amount of the working tool.

As another method for correcting the position of the sensor portion 12, a block which has been precisely processed in advance is installed inside the free curved surface processing apparatus 1 and the shape of the workpiece 10 is measured prior to the measurement. The shape of each side of this block is measured. The position of the sensor unit 12 and the measurement sensitivity can be calibrated based on the measured value. The block may have any shape as long as it can reflect the focused laser beam, and the block itself can be processed by the processing machine of this embodiment and placed inside.

In the above embodiment, an example in which an optical sensor is used as the sensor unit 12 has been described. However, the sensor unit 12 is not limited to the optical type, and a conventional three-dimensional measuring device is used. You may use the contact-type sensor mounted in. In this case, the tip shape of the contact probe is made spherical with a curvature close to the shape of the processed portion of the grindstone 9 so that the scanning locus of the sensor matches the working locus of the grindstone 9 as a machining tool. Is desirable. As a result, when measuring the shape of the free-form surface, the contact probe always keeps a constant angle with respect to the normal line of the measurement point, and the measurement is performed with high accuracy on the order of nanometers. Is possible. Further, when the contact type probe is used, unlike the optical type, there is an advantage that the measurement is not influenced by the reflectance of the workpiece.

Further, in the above embodiment, an example of cutting and grinding was described as the processing method, but the processing method is not limited to this, and other processing methods can be used.

For example, a processing method using plasma CVM, which is drawing attention as a new processing method that replaces the conventional mechanical processing, can be used. This plasma CVM
The processing principle is that a neutral radical molecule generated by locally generating high-pressure plasma is caused to act on a workpiece to perform processing, which is a chemical processing method suitable for ultra-precision processing. However, in the past, as with other cutting and grinding processes, the processing and measurement processes were separated, and no matter how precise the processing could be performed, it had to be removed from the processing device after each measurement. There is. Therefore, if a machining tool using the principle of CVM machining is adopted as the machining technique of the machining tool of the present invention, the conventional defects can be improved.

Further, as a machining method other than the above, the machining apparatus of the present invention is applied to the formation of a free-form surface by electric discharge machining and laser machining of YAG (yttrium-aluminum-garnet), excimer, etc. be able to. That is, the processing apparatus of the present invention is equipped with a shape measuring instrument, and by measuring the three-dimensional shape of the workpiece on this apparatus, it is possible to increase the position without damaging the positional relationship between the surface to be processed and the processing tool. Can measure accurate three-dimensional shapes. Then, as a result of this measurement, in the portion where the shape error is generated, it is possible to perform pinpoint correction processing on the workpiece, and it is possible to greatly reduce the processing time and the measurement time.

As described above, according to the free-form surface processing apparatus of this embodiment, the workpiece 10 is processed by mounting the sensor section 12 as a non-contact three-dimensional shape measuring instrument on the ultra-precision feeding mechanism. It is possible to measure the three-dimensional shape with high accuracy without removing it from the device 1. In addition, correction processing can be performed based on this measurement data.

Therefore, according to the above-described embodiment, the shape of the workpiece is measured by using a separately expensive measuring device,
It is not necessary to attach it to the processing machine again to perform processing. Therefore, a processing error due to a mounting error can be eliminated in principle. Therefore,
According to this embodiment, the processing measurement accuracy and the shape measurement accuracy can be improved, the processing and measurement time can be shortened, and the cost of the processing apparatus can be reduced.

Further, in the above embodiment, when the shape of the free curved surface of the workpiece 10 is measured, even if the surface to be measured of the workpiece 10 has an inclination, the reflected light from the surface to be measured is correctly reflected by the optical system. The inclination of the sensor unit 12, which is the shape measuring instrument, is corrected for the surface to be measured so that the surface to be measured passes through the optical axis. Therefore, the three-dimensional shape of the workpiece 10 can be measured with high accuracy, and it can be applied to any processing apparatus that processes a three-dimensional shape.

In the above embodiment, the laser beam is used for measuring the three-dimensional shape. However, any type of shape measuring instrument can be used as long as the three-dimensional shape can be measured in a non-contact manner. Good. By performing shape measurement while sequentially correcting the angle of the sensor unit so that the sensor unit of this shape measuring instrument always maintains a constant angle with respect to the normal line of the shape measuring point, a measurement error factor due to the inclination of the surface to be processed Therefore, it becomes possible to perform highly accurate shape measurement.

[0120]

As is apparent from the above, in the free-form surface machining apparatus of the present invention, the feed mechanism for moving the machining tool with respect to the work piece moves the shape measuring instrument with respect to the work piece. , Measure the free-form surface shape of the work piece. Therefore, according to the present invention, the shape measuring instrument is moved with respect to the work piece by using the feed mechanism for the working tool without removing the work piece from the processing device, thereby processing the work piece. The shape of the free-form surface can be measured accurately in a short time. Then, the correction processing can be performed again based on the free-form surface shape of the surface to be processed, which is accurately measured by this shape measuring instrument.

As described above, according to the present invention, it is not necessary to remove the workpiece from the processing apparatus, it is not necessary to measure the shape of the workpiece using a separately expensive measuring apparatus, and the processing apparatus can be processed again. There is no need to attach a work piece and perform processing. Further, for that reason, a processing error due to an installation error can be eliminated in principle, and processing accuracy can be improved, shape measurement accuracy can be improved, measurement time can be shortened, and the cost of the processing apparatus can be reduced.

In addition, in one embodiment, since the feeding mechanism is an ultra-precision feeding mechanism, precise position correction of the measuring instrument can be performed with an accuracy of the submicron order.

Further, in one embodiment, the feeding mechanism is
The feed direction can be controlled in the X-axis, Y-axis, Z-axis, A-axis, and B-axis directions. Therefore, by controlling the feed direction of each axis when measuring the shape of the surface to be processed of the work piece, the non-contact shape measuring instrument can be placed in the most suitable posture for the most accurate measurement.

Further, in one embodiment, when the shape measuring instrument measures the shape of the workpiece, the posture of the shape measuring instrument is determined by the normal line of the measurement site of the processed surface of the workpiece. The feed mechanism corrects the angle of the shape measuring instrument so as to maintain a predetermined angle. Thus, the angle of the shape measuring instrument is corrected so as to maintain a predetermined angle with the normal line of the processing point of the surface to be processed, whatever the shape of the surface to be processed of the workpiece. be able to. Therefore,
It is possible to eliminate an error factor of shape measurement due to the inclination of the surface of the workpiece to be measured, and it is possible to perform highly accurate three-dimensional shape measurement.

[0125] In one embodiment, the feeding mechanism is
At the time of processing, while performing the angle correction of the processing tool such that the posture of the processing tool with respect to the surface of the workpiece to be processed maintains a predetermined angle with the normal to the processing portion of the surface to be processed, The above-mentioned work piece is processed by a tool. Further, at the time of shape measurement, while performing the angle correction of the shape measuring instrument such that the measurement posture of the shape measuring instrument with respect to the surface to be processed maintains a predetermined angle with the normal line of the processing point of the surface to be processed, A processing point on the surface to be processed is measured by a shape measuring instrument.

Therefore, in this embodiment, at the time of machining, machining can be performed at one point (same position) of the machining tool, and at the time of measuring the shape, the angle of the shape measuring instrument is corrected to measure the object to be measured. The shape measurement error factor due to the inclination of the surface can be eliminated.

Further, in one embodiment, the feed mechanism feeds the shape measuring device so as to trace a locus approximately the same as the machining locus of the machining tool. Therefore, it can be seen that the distance data between the workpiece and the workpiece measured by this shape measuring instrument has a small variation and is substantially constant, and the portion having the variation in the distance data is the portion where the machining needs to be corrected. Therefore, the correction processing can be performed pinpoint only at the portion where the processing correction is required, and the processing time and the shape measurement time can be significantly reduced.

Further, in one embodiment, since the shape measuring instrument measures the shape of the work piece using the laser beam, the free-form surface of the work piece is non-contacted with the work piece. It is possible to measure the shape. In addition, measurement is performed while correcting the angle of the shape measuring instrument so that the measurement posture (position) of the shape measuring instrument with respect to the processing surface always maintains a predetermined angle with the normal line of the processing point of the processing surface. Thus, the factor of measurement error due to the inclination of the surface to be processed can be eliminated, and highly accurate non-contact three-dimensional shape measurement can be performed.

In one embodiment, the movement and the angle correction of the shape measuring instrument at the time of shape measurement are performed based on the feed trajectory for moving the processing tool and the information of the angle correction of the processing tool at the time of processing. Since it is done, it is possible to trace the shape measuring instrument according to the trajectory of the machining tool during machining,
The shape measurement time can be shortened. Further, in the case where the shape measuring instrument uses laser light, by tracing the trajectory of the processing tool during processing, the focus shift of the sensor unit becomes very small, and the shape measuring time can be shortened.

[0130] In one embodiment, when the shape measuring device measures the shape of the work surface of the work piece based on the data obtained by measuring the shape of the work surface of the work piece, The program for controlling the feed of the machining tool or the data for numerical control is corrected. As a result, the surface to be processed of the workpiece can be easily and accurately corrected.

Further, in one embodiment, since the shape measuring instrument is mounted on the tool base that supports the machining tool, the shape at the time of measuring the shape is measured based on the angle correction information of the machining tool at the time of machining. The angle of the measuring instrument can be corrected, the shape measuring instrument can be easily moved according to the trajectory of the machining tool during machining, and the shape measuring time can be shortened.

Further, in one embodiment, since the shape measuring instrument is mounted on the tool stand facing 180 ° opposite to the machining tool, the shape measuring instrument is mounted on the machining tool during machining. It is kept away from the processing dust that is scattered by the discharged cooling air, oil, etc., and prevents these from adhering to the shape measuring instrument.

Further, in one embodiment, when measuring the shape of the workpiece, the ultra-precision feed mechanism moves the non-contact three-dimensional shape measuring instrument based on the machining program to move the tertiary shape of the workpiece. Perform original shape measurement. This machining program is a feed control program that causes the ultra-precision feed mechanism to move the machining tool when machining the workpiece with the machining tool.

Therefore, according to this embodiment, the non-contact three-dimensional shape measuring instrument can be moved along the same trajectory as the machining tool. Therefore,
From the three-dimensional shape measurement data of this non-contact three-dimensional shape measuring instrument, the amount (error) in which the actual machining shape deviates from the target shape by the above machining program can be immediately obtained. Then, based on the three-dimensional shape measurement data, the machining program is modified so as to compensate for the error.
As a result, it is possible to perform pinpoint correction processing only on a portion that requires processing correction, and it is possible to greatly reduce processing time and shape measurement time.

Further, in one embodiment, the shape measuring instrument is moved by the ultra-precision feeding mechanism so that the machining tool traces the same trajectory as when the workpiece is machined, and the shape measurement is performed. The shape of the workpiece is measured with a measuring instrument.
Based on the measured shape (data), the wear amount of the working tool during the working is measured. Then, this measured amount of wear is immediately used for the wear correction program of the machining program.
(Data for numerical control) can be reflected. Therefore, it is possible to easily correct the feed by the feed mechanism in response to the wear of the machining tool which is a factor of the machining shape error.

[Brief description of drawings]

FIG. 1 is a front view showing a first embodiment of a free-form surface processing apparatus of the present invention.

FIG. 2 is a perspective view of a workpiece to be processed in the first embodiment.

FIG. 3 is a detailed view showing a state where a workpiece is being processed in the first embodiment.

FIG. 4 is a detailed view showing how the shape of the workpiece is being measured in the first embodiment.

[Explanation of symbols]

1 ... Free curved surface processing device, 2 ... Base, 3 ... Z stage,
4 ... Headstock, 5 ... X stage, 6 ... B stage, 7 ... Y
Stage, 8 ... Tool stand, 9 ... Whetstone, 10 ... Workpiece,
10a ... Work surface, 11 ... Tool part, 12 ... Sensor part, 13 ... Objective lens.

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Claims (13)

[Claims] 1. A processing machine for processing a workpiece by moving a machining tool with respect to the workpiece by a feed mechanism, wherein the machining tool is moved with respect to the workpiece by the feed mechanism, A free-form surface processing apparatus comprising a shape measuring instrument for measuring the shape of the workpiece by measuring the distance to the workpiece. 2. The free-form surface processing apparatus according to claim 1, wherein the feed mechanism is an ultra-precision feed mechanism, and the position of the measuring instrument is corrected by the ultra-precision feed mechanism. Processing equipment. 3. The free-form surface processing apparatus according to claim 1, wherein the feed mechanism has at least a feed direction in the X-axis direction, a Y-axis direction orthogonal to the X-axis, and the X-axis. And a Z-axis direction orthogonal to the Y-axis, an A-direction which is a rotation direction around the X-axis, and a B-direction which is a rotation direction around the Y-axis. A non-contact shape measuring instrument for measuring the shape of the work piece without contacting the work piece, the non-contact shape measuring instrument being moved with respect to the work piece by the feed mechanism. A free-form surface processing apparatus which measures the shape of the workpiece and is position-corrected by the feed mechanism. 4. The free-form surface processing apparatus according to claim 1, wherein the feed mechanism has the posture of the shape measuring instrument when the shape measuring instrument measures the shape of the workpiece. An apparatus for processing a free-form surface, wherein the angle of the shape measuring instrument is corrected so as to maintain a predetermined angle with a normal to a measurement site on the surface of the workpiece. 5. The free-form surface processing apparatus according to claim 1, wherein the feed mechanism is configured such that a posture of the processing tool with respect to a surface to be processed of the workpiece is a processing portion of the surface to be processed during processing. While performing the angle correction of the processing tool so as to maintain a predetermined angle with the normal line, the workpiece is processed by the processing tool. Measure the machining point of the work surface by the shape measuring instrument while correcting the angle of the shape measuring instrument so that the measurement posture maintains a predetermined angle with the normal to the machining point of the work surface. Free-form surface processing device characterized by: 6. The free-form curved surface machining apparatus according to claim 1, wherein the feed mechanism is configured such that a machining attitude of the machining tool with respect to a surface of the workpiece to be machined is such that the machining surface of the workpiece is machined. While sending the processing tool while correcting the angle of the processing tool so as to maintain a predetermined angle with the normal line of the point, the posture of the shape measuring instrument is set to the work surface of the workpiece during shape measurement. While the angle of the shape measuring instrument is corrected so as to maintain a predetermined angle with respect to the normal line of the measurement site, the shape measuring instrument causes the locus to be substantially the same as the machining locus of the workpiece by the machining tool. A free-form surface processing device characterized by sending the above-mentioned shape measuring device so as to trace the. 7. The free curved surface processing apparatus according to claim 1, wherein the shape measuring instrument is a shape measuring instrument that measures a shape of a workpiece by using a laser beam. A free-form surface processing device characterized in that 8. The free-form surface machining apparatus according to claim 1, wherein the feed mechanism is configured to operate the machining tool when the machining tool processes a machining surface of the workpiece. A free-form surface processing apparatus, characterized in that the shape measuring instrument is moved and the angle of the shape measuring instrument is corrected based on a feed trajectory to be moved and information on the angle correction of the processing tool during processing. 9. The free-form surface machining apparatus according to claim 1, wherein the feed mechanism controls the feed by a program or data for numerical control, and the shape measuring instrument is the workpiece. Correct the program or numerical control data that controls the feed of the processing tool when processing the processing surface of the workpiece with the processing tool, based on the data obtained by measuring the shape of the processing surface of the processing object. A free-form surface processing device characterized in that 10. The free-form surface processing apparatus according to claim 1, wherein the shape measuring instrument is mounted on a tool base that supports the processing tool. Processing equipment. 11. The free-form surface machining apparatus according to claim 10, wherein the shape measuring instrument is mounted on the tool base facing 180 ° opposite to the machining tool. Curved surface processing equipment. 12. The shape of the workpiece is measured by moving the processing tool with the ultra-precision feed mechanism to process the workpiece, and moving the non-contact three-dimensional shape measuring instrument with the ultra-precision feed mechanism. A free-form surface processing method using a free-form surface processing apparatus, wherein the ultra-precision feed mechanism is based on a processing program, and the X-axis, Y-axis, Z-axis directions orthogonal to each other and the A-direction around the X-axis, Feed control is possible in the B direction around the Y-axis, and when measuring the shape of the workpiece, the attitude of the non-contact three-dimensional shape measuring instrument is based on the machining program by the ultra-precision feeding mechanism. The non-contact three-dimensional shape measuring instrument is moved while performing the angle correction of the non-contact three-dimensional shape measuring instrument so as to maintain a predetermined angle with the normal line of the measured part of the workpiece, The 3D shape of the object is measured, Based on the shape measurement data, the machining program is modified, and the ultra-precision feed mechanism moves the machining tool according to the modified machining program to machine the workpiece. Curved surface processing method. 13. A free-form surface machining method using a free-form surface machining apparatus having an ultra-precision feed mechanism, wherein the machining tool traces a locus substantially the same as a locus when a workpiece is machined. With the feed mechanism, the shape measuring instrument is moved, and the shape measuring instrument measures the shape of the workpiece to measure the amount of wear of the processing tool during the machining, and based on the measured amount of wear. And a free-form surface machining that corrects a machining program for controlling the feed of the machining tool by the ultra-precision feed mechanism or numerical control data for controlling the feed of the machining tool by the ultra-precision feed mechanism. Method.