JP2003300129A - Processing device and control method therefor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To restrain deterioration of processing precision due to inclination of a rotational shaft attached to a workpiece or a processing tool at low cost and high precision. <P>SOLUTION: This processing device 1 comprises a rotational shaft 10 rotatably supported by any one of mobile tables 2, 3 and 4; a shaft drive motor 15 rotating and driving the rotational shaft 10; a control device 60 giving position instruction signals Sx, Sy, Sz to the respective mobile tables 2, 3 and 4; a plurality of inclination sensors 55 and an angle calculation circuit 63 for detecting an angle α around an X axis, an angle ϕ around a Y axis, and an angle θ around a Z axis designating inclinations from an ideal rotational shaft of a central axis 10a of the rotational shaft 10; and a correction circuit 64 for generating position instruction signals Sx', Sy' and Sz' in such a manner that a real contact is consistent with a target contact between a workpiece WP and a processing tool T, using the detected angles α, ϕ, and θ. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a machining apparatus for machining a workpiece while bringing the workpiece and a tool into contact with each other at a target contact point and moving the both relatively.

[0002]

2. Description of the Related Art Conventionally, as a processing device capable of performing precise cutting or grinding, any one of three moving tables corresponding to the X-axis, Y-axis and Z-axis of a Cartesian coordinate system and one of the moving tables has been used. It is known to have a rotating shaft integrally rotatably supported. In such a processing apparatus, one of the workpiece and the processing tool is attached to the rotary shaft, and the other is attached to one of the other moving tables that do not support the rotary shaft. Then, this type of processing apparatus rotates the rotary shaft and moves each moving table while bringing the workpiece and the processing tool into contact with each other at the target contact point. As a result, the workpiece and the processing tool move relative to each other, and the workpiece is subjected to predetermined processing by the processing tool.

In the processing apparatus as described above, the central axis of the rotary shaft that is being driven to rotate is caused by an error in the dynamic balance of the rotary shaft, an imbalance in the magnetic characteristics of the motor that drives the rotary shaft, and the like. Ideal rotation axis (X axis, Y
The axis may be slightly tilted from an axis parallel to any one of the axis and the Z axis). Such an inclination of the rotating shaft causes a deviation between an actual contact point (processing point) between the workpiece and the processing tool and a target contact point that is predetermined in the XYZ orthogonal coordinate system during processing. Therefore, in order to perform precision machining, it is necessary to somehow correct the influence of the inclination of the rotary shaft during machining. As a processing apparatus provided with a means for correcting the deviation between the processing point and the target contact point, there is conventionally known one as shown in FIG.

A processing apparatus 101 shown in FIG. 7 is an X-axis moving table 102 which is movable in the X-axis direction of a rectangular coordinate system.
And a Y-axis movement table (not shown) movable in the Y-axis direction of the orthogonal coordinate system, and a Z-axis movement table 103 movable in the Z-axis direction of the orthogonal coordinate system. In this case, the X-axis moving table 102 is movably mounted on a Y-axis moving table (not shown). A fine movement table 104 is movably mounted on the X-axis movement table 102.
The fine movement table 104 is moved to Z
It can be moved back and forth with high accuracy in the axial direction. Micro table 10
A processing tool T for cutting or grinding the workpiece WP is attached on the workpiece 4.

Further, the processing apparatus 101 has a Z coordinate system.
It has a rotating shaft 105 extending in the axial direction. In the processing apparatus 101, the workpiece WP is attached to the tip of the rotary shaft 105 so as to face the processing tool T on the correction table 104. The rotating shaft 105 is rotatably supported by a bearing (not shown) arranged in the motor housing 106. Also, the rotating shaft 105
On the other hand, a rotor (not shown) is fixed, and on the other hand, in the housing 106, a stator that constitutes a shaft drive motor together with the rotor of the rotary shaft 105 is fixed.

Further, the processing apparatus 101 includes a laser interferometer 107 capable of emitting a laser beam L in the Z-axis direction in addition to a laser interferometer (not shown) for detecting the positions of the movable tables 102, 103 and the like. Have multiple. These laser interferometers 107 are arranged on a stationary surface plate (not shown) and are adjacent to each other in the X-axis direction. A reflection mirror 108 having a reflection surface parallel to the XY plane is provided on the rear end surface of the motor housing 106 supporting the rotation shaft 105.
Are fixed so as to face each laser interferometer 104. Each of the laser interferometers 107 is based on the emission timing of the laser light L, the incidence timing of the reflected light from the reflection mirror 108, etc.
The distance (movement distance of the Z-axis movement table 103) from the position 08 is measured.

In the processing apparatus 101 configured as described above, the Z-axis moving table 1 is moved by the laser interferometers 107.
The moving distance of 03 is measured at a plurality of positions in the X-axis direction, and the inclination of the central axis 105a of the rotating shaft 105 with respect to the ideal rotating axis is based on the difference (deviation) between the measured values of the laser interferometers 107. Asked for. Then, the fine movement table 104 holding the processing tool T is slightly moved in the Z-axis direction according to the obtained inclination. As a result, the deviation between the machining point and the target contact point caused by the inclination of the rotary shaft 105 is reduced.

[0008]

However, in the above-described conventional processing apparatus, the measurement of the inclination of the rotary shaft and the correction of the position of the processing tool using the same are performed in one direction (Z-axis direction, that is, in the orthogonal coordinate system). , Thrust direction). Therefore, the conventional processing equipment
The deviation between the processing point and the target contact point due to the inclination of the rotary shaft still exists, and it becomes difficult to further improve the processing accuracy. Further, in order to correct the deviation between the processing point and the target contact point in only one direction of the orthogonal coordinate system, a plurality of expensive exclusive laser interferometers are required, and further the structure and control are complicated. The requirement for an expensive fine movement table is problematic in terms of cost efficiency.

Therefore, an object of the present invention is to provide a processing apparatus and a control method therefor capable of reliably suppressing the deterioration of the processing accuracy due to the inclination of the rotary shaft on which the workpiece or the processing tool is attached at low cost.

[0010]

According to one aspect of the present invention, there is provided a processing apparatus capable of processing a workpiece while bringing the workpiece and a tool into contact with each other at a target contact point and moving the both relatively. Pertain. This processing apparatus is capable of moving in the X-axis direction of the Cartesian coordinate system, a Y-axis moving table capable of moving in the Y-axis direction of the Cartesian coordinate system, and movable in the Z-axis direction of the Cartesian coordinate system. A Z-axis moving table, a rotary shaft that can hold a workpiece or a processing tool, and is rotatably supported by any one of the moving tables; a shaft driving unit that rotationally drives the rotary shaft; Control means for giving a position command signal to the moving table, and inclination for detecting an angle α around the X axis, an angle φ around the Y axis, and an angle θ around the Z axis, which indicates the inclination of the central axis of the rotary shaft from the ideal rotation axis. Using the detection means and the angles α, φ and θ detected by the inclination detection means, a position command signal for each moving table so that the actual contact point and the target contact point between the workpiece and the processing tool coincide with each other. To correct And a positive means.

In this processing apparatus, one of the work piece and the processing tool is attached to a rotary shaft that is rotatably supported by any one of the moving tables, and the other one supports the rotary shaft. Not attached to one of the other moving tables. Then, when the rotary shaft is rotated and each movable table is moved to process the workpiece, the tilt detecting means detects the tilt of the rotary shaft by an angle α about the X axis, an angle φ about the Y axis, and The angle θ around the Z axis is detected.

Here, if the rotary shaft is tilted by an angle α around the X axis, an angle φ around the Y axis and an angle θ around the Z axis, the target contact point for contacting the workpiece and the working tool. If is not the coordinate with respect to the workpiece, the actual contact point and the target contact point will be misaligned. That is, in order to eliminate the deviation between the actual contact point and the target contact point when the rotating shaft is tilted, the UVW is a virtual coordinate system tilted by an angle α from the X axis, an angle φ from the Y axis, and an angle θ from the Z axis. Each moving table should be moved with reference to the Cartesian coordinate system. In view of this point, in this processing apparatus, the correction means causes an actual contact point (a contact point between the workpiece and the processing tool, which will be determined by each movement table moved according to the uncorrected position command signal from the control means). The position command signal sent from the control means to each moving table is corrected so that the processing point) is rotated by an angle α around the X axis, an angle φ around the Y axis, and an angle θ around the Z axis.

As a result, even if the rotary shaft is tilted when the target contact point is defined with reference to the XYZ coordinate system, the actual contact point between the workpiece and the tool is the original contact point on the workpiece. The target contact point is accurately matched, and the processing accuracy is further improved. Further, this processing apparatus does not require a dedicated moving table or range finder for correcting the deviation between the actual contact point and the target contact point due to the inclination of the rotary shaft, and thus suppresses the cost increase. be able to.

Another embodiment of the present invention also relates to a processing apparatus capable of processing a work piece while bringing the work piece and the work tool into contact with each other at a target contact point and relatively moving them. This processing apparatus is capable of moving in the X-axis direction of the Cartesian coordinate system, a Y-axis moving table capable of moving in the Y-axis direction of the Cartesian coordinate system, and movable in the Z-axis direction of the Cartesian coordinate system. Z
A shaft moving table, a rotating shaft capable of holding a workpiece or a processing tool, and rotatably supported by any one of the moving tables, a shaft driving means for rotationally driving the rotating shaft, and each moving The table position data stored in the storage means is provided with a control means for giving a position command signal to the table and a storage means for storing table position data for generating a position command signal given to each moving table from the control means. , The angle α around the X axis, the angle φ around the Y axis, and the angle θ around the Z axis, which indicate the inclination of the central axis of the rotating shaft from the ideal rotating axis, which is detected in advance according to the rotating speed of the rotating shaft. In addition, the actual contact point and the target contact point between the work piece and the processing tool are preliminarily corrected so as to coincide with each other.

The inclination of the rotating shaft is caused by an error in the dynamic balance of the shaft, a force resulting from an imbalance in the magnetic characteristics of the motor that drives the rotating shaft, or the like acting on the rotating shaft. The force to tilt the shaft increases in proportion to the rotational speed of the rotating shaft. Therefore, instead of detecting the inclination of the rotating shaft during processing, angles α, Y around the X axis indicating the inclination of the central axis of the rotating shaft from the ideal rotation axis for a plurality of rotation speeds.
If the angle φ about the axis and the angle θ about the Z axis are detected in advance, it is possible to grasp (estimate) the characteristics of the inclination of the rotary shaft in the range of the rotation speed during processing. Then, in this processing device, the detected angles α, φ and θ,
That is, the table position data for generating the position command signal for each moving table is corrected in advance based on the grasped inclination characteristics.

As described above, even if each moving table is operated by using the table position data that is corrected in advance, the actual contact point between the workpiece and the processing tool is the original target contact point on the workpiece. With high accuracy, the processing accuracy is further improved. Furthermore, even in this processing apparatus, a dedicated moving table or range finder for correcting the deviation between the actual contact point and the target contact point due to the inclination of the rotating shaft is not required, and the cost increase associated therewith is suppressed. be able to.

Yet another aspect of the present invention relates to a method of controlling a processing apparatus. The processing apparatus that is the target of this method is an X-axis moving table that can move in the X-axis direction of the Cartesian coordinate system, a Y-axis moving table that can move in the Y-axis direction of the Cartesian coordinate system, and a Z-axis direction of the Cartesian coordinate system. A movable Z-axis moving table, a rotary shaft that can hold a workpiece or a processing tool, and is rotatably supported by any one of the moving tables, a shaft driving unit that rotationally drives the rotary shaft, and It has a control means for giving a position command signal to each moving table, and makes it possible to work the work piece while bringing the work piece and the work tool into contact with each other at a target contact point and relatively moving them. Further, in this method, when the rotary shaft is rotationally driven by the shaft driving means, an angle α around the X axis, an angle φ around the Y axis, and a Z axis indicating the inclination of the central axis of the rotary shaft from the ideal rotary axis. The surrounding angle θ is detected, and the detected angle α, φ, and θ are used to correct the position command signal for each moving table so that the actual contact point and the target contact point between the workpiece and the processing tool match. .

Another aspect of the present invention also relates to a method of controlling the processing apparatus. The processing apparatus that is the target of this method is an X-axis moving table that can move in the X-axis direction of the Cartesian coordinate system, a Y-axis moving table that can move in the Y-axis direction of the Cartesian coordinate system, and a Z-axis direction of the Cartesian coordinate system. A movable Z-axis moving table, a rotary shaft capable of holding a workpiece or a processing tool, and rotatably supported by any one of the moving tables;
It has a shaft driving means for rotationally driving the rotary shaft and a control means for giving a position command signal to each moving table. The workpiece and the tool are brought into contact with each other at a target contact point, and the workpiece and the tool are moved relative to each other. The processed body can be processed. In this method, while rotating the rotary shaft by the shaft driving means, an angle α around the X axis indicating an inclination of the central axis of the rotary shaft from the ideal rotation axis, an angle φ around the Y axis, and a angle around the Z axis. The angle θ is detected in advance according to the rotation speed of the rotating shaft, and the detected angle α,
Using φ and θ, the table position data for each moving table is corrected so that the actual contact point of the workpiece and the target contact point coincide with the target contact point, and each movement is performed using the corrected table position data. Make the table work.

[0019]

BEST MODE FOR CARRYING OUT THE INVENTION Preferred embodiments of a processing apparatus and a control method thereof according to the present invention will be described in detail below with reference to the drawings.

FIG. 1 is a perspective view showing an embodiment of a processing apparatus according to the present invention. The processing device 1 shown in FIG.
The workpiece WP and the processing tool T are brought into contact with each other at a target contact point, and the workpiece WP can be processed while relatively moving them. In order to relatively move the workpiece WP and the processing tool T, the processing apparatus 1 includes an X-axis moving table 2 that is movable in the X-axis direction of the XYZ orthogonal coordinate system, and a Y of the orthogonal coordinate system.
It has a Y-axis moving table 3 movable in the axial direction and a Z-axis moving table 4 movable in the Z-axis direction of the orthogonal coordinate system.

In this embodiment, the XY surface plate 6 is fixed on the surface plate 5, and the X-axis moving table 2 is movably supported on the XY surface plate 6. X-axis moving table 2
Are guided in the X-axis direction by the linear guide 7. X
A linear motor movable part 21 is fixed to both sides of the axis moving table 2 (only one side is shown in FIG. 1), and a corresponding linear motor movable part of the X axis moving table 2 is attached to the surface plate 5. A linear motor fixing portion 22 that constitutes the X-axis linear motor 20 is arranged together with the portion 21. By operating each X-axis linear motor 20, the X-axis moving table 2 can be reciprocated in the X-axis direction on the surface plate 5.

The X-axis moving table 2 is mounted on the surface plate 5.
X-axis position sensors 23 including a laser interferometer are arranged so as to be located on both sides of the. Each X-axis position sensor 23
Emits the laser beam Lx in the X-axis direction to the corresponding reflection mirror 24 attached to the side portion of the X-axis moving table 2, and the distance between the light incident / exiting portion and the reflection mirror 24 (X-axis movement). The moving distance of the table 2 with respect to the surface plate 5 is measured.

The X-axis moving table 2 has a linear guide 25 extending in the Y-axis direction.
A Y-axis moving table 3 is slidably arranged on the upper side. A linear motor moving part 31 is fixed to both sides of the Y-axis moving table 3, and a Y-axis linear moving part 31 is fixed on the X-axis moving table 2 together with a corresponding linear motor moving part 31 of the Y-axis moving table 3. The linear motor fixing portions 32 forming the motor 30 are arranged in parallel with each other. By operating each Y-axis linear motor 30, the Y-axis moving table 3 can be reciprocated in the Y-axis direction on the X-axis moving table 2.

On the X-axis moving table 2, Y-axis position sensors 33 including a laser interferometer are arranged so as to be located on both sides of the Y-axis moving table 3. Each Y-axis position sensor 33 emits a laser beam Ly in the Y-axis direction to a corresponding reflection mirror 34 attached to the side of the Y-axis moving table 3 so that the laser beam Ly is emitted between the light input / output unit and the reflection mirror 34. (The moving distance of the Y-axis moving table 3 with respect to the X-axis moving table 2) is measured. And in this embodiment,
The processing tool T is mounted on a support base 35 fixed on the Y-axis moving table 3.

Further, a Z-axis table guide 8 is erected on the surface plate 5, and the Z-axis table guide 8 allows Z
The axis moving table 4 is supported slidably in the Z-axis direction. The linear motor movable part 41 is fixed to both sides of the Z-axis moving table 4, and the Z-axis table guide 8 is provided.
The linear motor fixing portions 42 that configure the Z-axis linear motor 40 together with the corresponding linear motor movable portions 41 of the Z-axis moving table 4 are arranged in parallel with each other. By operating each Y-axis linear motor 40, the Z-axis moving table 4 can be reciprocated in the Z-axis direction with respect to the surface plate 5.

The Z-axis moving table 4 is mounted on the surface plate 5.
A Z-axis position sensor 43 including a laser interferometer is arranged so as to correspond to both sides of the. Each Z-axis position sensor 4
3 emits the laser beam Lz in the Z-axis direction to the corresponding reflection mirror 44 attached to the side portion of the Z-axis moving table 4, and the distance (Z
The moving distance of the axis moving table 3 with respect to the surface plate 5 is measured. In the present embodiment, the rotary shaft 1 for mounting the workpiece WP by the Z-axis moving table 4.
0 is rotatably supported.

As shown in FIG. 2, the rotary shaft 10 is rotatably supported by a hydrostatic bearing 50 supported by the Z-axis moving table 4 while extending in the Y-axis direction. The hydrostatic bearing 50 is supported in a motor housing 45 fixed to the Z-axis moving table 4. A fixing member 11 for attaching the workpiece WP is fixed to one end of the rotating shaft 10, and a rotor 12 is fixed to the other end of the rotating shaft 10.
On the other hand, at the end of the motor housing 45, the stator 12 that constitutes the shaft drive motor 15 that rotationally drives the shaft 10 is arranged together with the rotor 12. By supplying electric power to the stator 14, the rotating shaft 10
Can be rotated forward or backward around the Y axis.

The hydrodynamic bearing 50, as shown in FIG.
The main body 51 includes a plurality of (two in the present embodiment) radial pads 52 and thrust pads 53, each of which is provided in the main body 51. Also, the rotating shaft 1
0 includes a flange portion 10f substantially at the center between the fixed member 11 and the rotor 12. In the present embodiment, the rotating shaft 10
One radial pad 5 on each side of the flange part 10f
2 are arranged. Further, on both sides of the flange portion 10f of the rotary shaft 10, one thrust pad 53 is arranged so as to face each end surface extending in the radial direction of the flange portion 10f.

The radial pads 52 and the thrust pads 53 are connected to a compressed fluid supply unit (not shown). Compressed fluid such as high-pressure air supplied from the compressed fluid supply unit is jetted from each radial pad 52 onto the axial surface of the rotary shaft 10. Further, from each thrust pad 53, compressed fluid such as high-pressure air supplied by the compressed fluid supply unit is jetted to each end surface of the flange portion 10f. As a result, the rotary shaft 10 is supported (restricted) in the radial direction (radial direction of the rotary shaft 10) by the compressed fluid film of each radial pad 52, and the thrust direction (in FIG. 2) by the compressed fluid film of each thrust pad 53. It will be supported (restricted) in the Y-axis direction. Each pad 52,
53, the surface of the rotary shaft 10 and the flange portion 10f
The distance from the end face of the is maintained at about several μm to 10 μm.

Further, as shown in FIG. 2, a plurality of capacitance type inclination sensors 55 (in this embodiment, a total of six bodies) are arranged in the motor housing 45. As shown in FIG. 3, in the present embodiment, three tilt sensors 55 are radially arranged on both sides of the flange portion 10f so as to face the rotary shaft 10 with a predetermined gap. The three inclination sensors 55 on one side of the flange portion 10f are arranged at 120 ° intervals in a plane parallel to the XZ plane. Each tilt sensor 55 can detect the distance from the shaft surface of the rotary shaft 10 with high accuracy.

FIG. 4 is a control block diagram of the processing apparatus 1 according to the present invention. As shown in the figure, the processing apparatus 1 includes a control device 60 that controls the operations of the moving tables 2, 3 and 4 and the rotary shaft 10 described above. The control device 60 has an MPU, a ROM, a RAM, an input / output interface, and the like.
The storage device 61 is connected to the (input / output interface). The storage device 61 stores each table 2 so that the workpiece WP is processed by the processing tool T as desired.
The position data (coordinate data based on the XYZ orthogonal coordinate system) of each moving table 2, 3 and 4 for moving 3 and 4 and rotating the rotary shaft 10 and rotation speed information of the rotary shaft 10 are stored. ing.

A motor driver 62 for driving the rotary shaft 10 is connected to the controller 60 (input / output interface). The control device 60 controls the shaft drive motor 15 via the motor driver 62 based on the rotation speed information stored in the storage device 61. Further, the control device 60 (input / output interface) has an X-axis position sensor 23, a Y-axis position sensor 33 and a Z-axis position sensor 23 for detecting the positions of the respective moving tables 2, 3 and 4.
The shaft position sensor 43 is connected. Each position sensor 2
3, 33 and 43 send the current position information of each moving table 2, 3 and 4 to the control device 60.

The controller 60 controls the position sensors 23 and 33.
And the respective moving tables 2, 3 and 4 sent from 43
Based on the table position data of the moving tables 2, 3 and 4 stored in the storage device 61 and the current position information of the X-axis linear motor 20 and the Y-axis linear motor 30.
And a position command signal S for the Z-axis linear motor 40
Generate x, Sy and Sz. That is, the control device 6
0 is a target that the workpiece WP and the processing tool T correspond to when the rotating shaft 10 is rotating around the ideal rotation axis by using a predetermined program stored in the storage device 61. Each moving table 2, so that they come in contact with each other
Position command signals Sx, S for moving 3 and 4
Generate y and Sz.

Further, the processing apparatus 1 includes a rotary shaft 10
In order to reduce the effect of the inclination of the angle calculation circuit 63, the angle calculation circuit 63 to which each of the inclination sensors 55 described above is connected, and the correction circuit 64 connected to the angle calculation circuit 63 and the control device 60.
Is provided. The angle calculation circuit 63 determines, based on a signal from each inclination sensor 55, during rotation of the rotary shaft 10 from the ideal rotation axis of the central axis 10a of the rotary shaft 10 (in a state parallel to the Y axis). An angle α around the X axis indicating an inclination, an angle φ around the Y axis, and an angle θ around the Z axis are calculated, and a signal Sα indicating the angle α, a signal Sφ indicating the angle φ, and a signal Sθ indicating the angle θ are corrected. To 64. That is, in the present embodiment, the plurality of tilt sensors 5
5 and the angle calculation circuit 63 function as inclination detecting means for detecting an angle α around the X axis, an angle φ around the Y axis, and an angle θ around the Z axis, which indicate the inclination of the rotary shaft 10 from the ideal rotation axis.

Then, as shown in FIG. 4, the position command signals Sx, Sy and Sz generated by the controller 60 are once sent to the correction circuit 64. Correction circuit 64
Using the angles α, φ and θ indicated by the signals Sα, Sφ and Sθ sent from the angle calculation circuit 63, the actual contact point and the target contact point between the workpiece WP and the processing tool T coincide with each other. Position command signals Sx, Sy and Sz are corrected as
The corrected position command signals Sx ', Sy' and Sz 'are sent to the respective movement tables 2, 3 and 4.

Next, the correction procedure of the position command signal in the correction circuit 64 will be specifically described.

First, in the processing apparatus 1, the rotary shaft 10
In some cases, not only the force in the rotating direction but also the force in the other direction may be generated on the rotating shaft 10 due to the error of the dynamic balance of the above, the imbalance of the magnetic characteristics of the motor 15 that drives the rotating shaft 10, and the like. . Then, when a force other than the rotational direction increases due to the high speed rotation of the rotary shaft 10 and the compressed fluid film of the fluid bearing 50 is further compressed, the center axis 10a of the rotary shaft 10 that is rotationally driven causes the supporting force of the fluid bearing 50 to increase. In order to maintain the balance with (rigidity), as shown by the chain double-dashed line in FIG. 5, within the range of the bearing clearance from the ideal rotation axis of the original XYZ orthogonal coordinate system (in the present embodiment, extending parallel to the Y axis). It will tilt slightly.

When the rotary shaft 10 is tilted from the ideal rotary shaft, the workpiece WP fixed to the rotary shaft 10 via the fixed member 11 is tilted together with the rotary shaft 10 and is shown by a chain double-dashed line in FIG. Take a posture like WP '. In this case, when the arbitrary target contact point Pw between the workpiece WP and the processing tool T, which is determined by the table position data stored in the storage device 61 in advance, is viewed with the XYZ orthogonal coordinate system as a reference, By tilting, it moves to the position Pw '. Therefore, simply using the position command signals Sx, Sy, and Sz generated under the assumption that the rotary shaft 10 is rotating around the ideal rotation axis, the workpiece can be processed depending on the inclination of the rotary shaft 10. The actual contact point (processing point) between the body WP and the processing tool T will deviate from the original target contact point (the target contact point when the rotating shaft 10 is not inclined). Note that FIG.
Shows an example in which the rotary shaft 10 is tilted around the Z axis by an angle θ. Further, although the inclination of the rotary shaft 10 is shown large in FIG. 1 for simplicity, the actual inclination amount is about 2 μrad.

Here, if the rotary shaft is inclined by the angle α around the X axis, the angle φ around the Y axis, and the angle θ around the Z axis, the workpiece WP and the processing tool T are brought into contact with each other. If the target contact does not have coordinates with the workpiece WP as a reference, the actual contact and the target contact will deviate. That is, in order to eliminate the deviation between the actual contact point and the target contact point when the rotating shaft 10 is tilted, the virtual coordinate system is tilted by an angle α from the X axis, an angle φ from the Y axis, and an angle θ from the Z axis. U
Each movement table 2, 3 and 4 should be moved with reference to the VW Cartesian coordinate system. In view of this, in the calculation processing in the correction circuit 64, with the central axis 10a ′ of the tilted rotary shaft 10 as the V axis, from the XYZ orthogonal coordinate system, the angle α around the X axis, the angle φ around the Y axis, and A Cartesian coordinate system UVW that is a virtual Cartesian coordinate system that is tilted around the Z axis by an angle θ is set.

Then, in the arithmetic processing in the correction circuit 64,

[0041]

[Equation 1]

Then,

[0043]

[Equation 2]

The coordinate conversion formula (1) is used.

In this case, (u, v,
w) is each position command signal Sx, S from the control device 60.
The X, Y, and Z coordinate data shown in y and Sz are substituted. Further, the angles α, φ and θ sent from the angle calculation circuit 63 to the correction circuit 64 are substituted into the coordinate conversion formula (1). Then, the correction circuit 64 causes the position command signal Sx ′ indicating x of the coordinates (x, y, z) obtained from the coordinate conversion formula (1), the position command signal Sy ′ indicating y, and the position command indicating z. The signal Sz 'is generated.

As a result, from the correction circuit 64, the X-axis linear motor 20 for driving each of the moving tables 2, 3 and 4,
In the Y-axis linear motor 30 and the Z-axis linear motor 30,
When the position command signals Sx ′, Sy ′ and Sz ′ are sent, the actual contact points (processing points) between the workpiece WP and the processing tool T are moved from the control device 60 by the respective moving tables 2, 3 and 4. Uncorrected position command signals Sx, Sz and Sx
The actual contact points between the workpiece WP and the processing tool T, which will be defined by the respective moving tables 2, 3 and 4, which have been moved in accordance with the above, are the angle α around the X axis, the angle φ around the Y axis, and the Z axis. It will be set at a position rotated by the angle θ.

As described above, in the processing apparatus 1, the tilt angles of the rotary shaft 10 around the X, Y and Z axes are measured,
The influence of the inclination of the rotating shaft 10 is corrected not only in the thrust direction (Y-axis direction) but also in the radial direction (around the X-axis and around the Z-axis). Therefore, the target contact is XYZ
Even if the rotary shaft 10 is tilted when the coordinate system is set as a reference, the actual contact point between the workpiece WP and the processing tool T accurately matches the original target contact point on the workpiece WP. Therefore, the processing accuracy is further improved.

Then, in the processing apparatus 1, such correction is performed by moving the respective moving tables 2, 3 and 4 which are essential for the processing operation. Therefore, a dedicated moving table and a position sensor (ranging meter) for correcting the deviation between the actual contact point and the target contact point due to the inclination of the rotating shaft 10 are not required, and the cost increase associated therewith is suppressed. You can Also, the rotating shaft 10
Is tilted within the bearing clearance of the fluid bearing 50,
The tilt sensor 5 has a small dynamic range and is inexpensive as compared with a laser length measuring device and includes an electrostatic capacitance sensor or the like.
Even if the value is 5, the inclination of the rotary shaft 10 can be measured accurately.

FIG. 6 is a perspective view showing another embodiment of the processing apparatus according to the present invention. Processing device 1A shown in FIG.
Then, the workpiece WP is mounted and fixed on the Y-axis moving table 3, and the processing tool T is attached to the rotary shaft 10 together with the counterweight 16. In the processing apparatus 1A shown in FIG. 6, in addition to the error of the dynamic balance of the shaft 10, the imbalance of the magnetic characteristics of the motor 15 that drives the rotating shaft 10, and the like, the processing tool T and the counterweight 1 are used.
The rotary shaft 10 may be tilted due to the mounting error of 6 or the like. However, even in such a processing apparatus 1A, if the influence of the tilt of the shaft 10 is corrected according to the above-described procedure, the workpiece will be processed. It is possible to accurately match the actual contact point between the body WP and the processing tool T with the original target contact point on the workpiece WP.

It should be noted that, in the above-described processing devices 1 and 1A, during rotation of the rotary shaft 10, an angle α around the X axis, an angle φ around the Y axis, and an angle θ around the Z axis, which indicate the inclination of the rotary shaft 10, are provided. Was detected and the detected angle α, φ and θ was used to correct the position command signal for each of the moving tables 2, 3 and 4, but the present invention is not limited to this.

That is, the inclination of the rotating shaft 10 is caused by an error in the dynamic balance of the shaft 10 and the rotating shaft 10.
A force resulting from an imbalance in the magnetic characteristics of the motor 15 that drives the rotary shaft 10 acts on the rotary shaft 10, and the force that tilts the rotary shaft 10 is basically the rotational speed of the rotary shaft 10. Increases in proportion to. Therefore, instead of detecting the inclination of the rotating shaft 10 during machining, the rotating shaft 10 is not detected for multiple rotation speeds.
If the angle α around the X axis, the angle φ around the Y axis, and the angle θ around the Z axis, which indicate the inclination of the central axis 10a from the ideal rotation axis, are detected in advance, the rotation is performed within the range of the rotation speed during processing. The inclination characteristic of the shaft 10 can be grasped (estimated).

Then, the angle α detected according to the number of revolutions,
If the inclination characteristic of the rotary shaft 10 is grasped from φ and θ, a table for generating the position command signals Sx, Sy and Sz for the respective movement tables 2, 3 and 4 by the grasped inclination characteristic of the rotary shaft 10. The position data can be corrected in advance so as to cancel the influence of the tilt of the rotary shaft 10. The table position data corrected in advance is stored in the storage device 61 and is used when operating the processing device 1.

Even if such a structure is adopted, the workpiece W is processed.
The actual contact point between P and the processing tool T coincides with the original target contact point on the workpiece WP with high accuracy, and the processing accuracy is further improved. Also in this case, a dedicated moving table and a position sensor for correcting the deviation between the actual contact point and the target contact point due to the inclination of the rotary shaft 10 are not necessary, and the cost increase associated therewith is suppressed. You can also The tilt of the rotary shaft 10 can be detected by using a plurality of tilt sensors attached to the rotary shaft 10 instead of the workpiece WP and the processing tool T.

[0054]

As described above, according to the present invention, it is possible to surely suppress the deterioration of the processing accuracy due to the inclination of the rotary shaft on which the workpiece or the processing tool is attached at low cost.

[Brief description of drawings]

FIG. 1 is a perspective view showing a processing apparatus according to the present invention.

FIG. 2 is a schematic configuration diagram showing a main part of the processing apparatus of FIG.

FIG. 3 is a perspective view schematically showing the arrangement of a tilt sensor.

FIG. 4 is a control block diagram of the processing apparatus of FIG.

FIG. 5 is a schematic diagram for explaining a procedure for correcting the influence of the inclination of the rotating shaft in the present invention.

FIG. 6 is a perspective view showing another embodiment of the processing apparatus according to the present invention.

FIG. 7 is a schematic configuration diagram showing a conventional processing apparatus.

[Explanation of symbols]

1,1A processing equipment 2 X-axis movement table 3 Y-axis moving table 4 Z-axis movement table 5 surface plate 6 XY surface plate 10 rotating shaft 10f Flange part 10a central axis 12 rotor 14 Stator 15 Shaft drive motor 16 counter weight 20 X-axis linear motor 23 X-axis position sensor 24, 34, 44 Reflective mirror 30 Y-axis linear motor 33 Y-axis position sensor 40 Z-axis linear motor 43 Z-axis position sensor 45 motor housing 50 fluid bearing 52 radial pad 53 Thrust pad 55 Tilt sensor 60 control device 61 storage device 63 Angle calculation circuit 64 correction circuit T processing tool W Workpiece

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) B23Q 1/00 Z F term (reference) 3C001 KA08 KB10 TA01 TB01 TC05 TD01 3C029 AA29 AA40 3C048 AA01 BB01 BC02 BC03 BC06 CC04 CC07 DD10 DD13 DD26 EE00 5H269 AB01 BB01 BB03 EE03 FF06 JJ01 MM05

Claims (4)

[Claims] 1. A processing apparatus capable of processing a workpiece while bringing the workpiece and a processing tool into contact with each other at a target contact point and moving them relative to each other, which is movable in the X-axis direction of a Cartesian coordinate system. An X-axis movement table, a Y-axis movement table that can move in the Y-axis direction of the Cartesian coordinate system, a Z-axis movement table that can move in the Z-axis direction of the Cartesian coordinate system, and the workpiece or the processing tool. A rotating shaft that can be held and is rotatably supported by any one of the moving tables, a shaft driving unit that rotationally drives the rotating shafts, and a control unit that gives a position command signal to each moving table. And an inclination detecting means for detecting an angle α around the X axis, an angle φ around the Y axis, and an angle θ around the Z axis, which indicate the inclination of the central axis of the rotating shaft from the ideal rotation axis, and the inclination detecting means. Using the angles α, φ and θ detected by the above, the position command signal for each moving table is corrected so that the actual contact point and the target contact point between the workpiece and the processing tool match. A processing apparatus comprising: a correction unit. 2. A processing apparatus capable of processing a workpiece while bringing the workpiece and a processing tool into contact with each other at a target contact point and relatively moving the both, and the workpiece can be moved in the X-axis direction of a rectangular coordinate system. An X-axis movement table, a Y-axis movement table that can move in the Y-axis direction of the Cartesian coordinate system, a Z-axis movement table that can move in the Z-axis direction of the Cartesian coordinate system, and the workpiece or the processing tool. A rotating shaft that can be held and is rotatably supported by any one of the moving tables, a shaft driving unit that rotationally drives the rotating shafts, and a control unit that gives a position command signal to each moving table. And a storage unit for storing table position data for generating a position command signal given to each of the movement tables from the control unit, and the table stored in the storage unit. The position data includes an angle α around the X axis, an angle φ around the Y axis, and an angle around the Z axis, which indicates the inclination of the central axis of the rotary shaft from the ideal rotation axis, which is detected in advance according to the rotational speed of the rotary shaft. A machining apparatus characterized in that the actual contact point and the target contact point between the workpiece and the processing tool are preliminarily corrected by utilizing θ. 3. An X-axis movement table movable in the X-axis direction of the Cartesian coordinate system, a Y-axis movement table movable in the Y-axis direction of the Cartesian coordinate system, and a Z-axis movable in the Z-axis direction of the Cartesian coordinate system. A moving table, a rotating shaft capable of holding the work piece or the processing tool, and rotatably supported by any one of the moving tables; a shaft driving means for rotationally driving the rotating shaft; A control means for giving a position command signal to each of the moving tables is provided, the workpiece and the processing tool are brought into contact with each other at a target contact point, and a processing apparatus capable of processing the workpiece while relatively moving the two is controlled. A method, wherein when the rotary shaft is rotationally driven by the shaft driving means, an angle α around the X axis indicating an inclination of a central axis of the rotary shaft from an ideal rotary axis, and an angle around the Y axis. The angle θ around φ and the Z axis is detected, and the detected angle α,
Using φ and θ, the position command signal for each moving table is corrected so that the actual contact point and the target contact point between the workpiece and the processing tool match. Control method. 4. An X-axis movement table movable in the X-axis direction of the Cartesian coordinate system, a Y-axis movement table movable in the Y-axis direction of the Cartesian coordinate system, and a Z-axis movable in the Z-axis direction of the Cartesian coordinate system. A moving table, a rotating shaft capable of holding the work piece or the processing tool, and rotatably supported by any one of the moving tables; a shaft driving means for rotationally driving the rotating shaft; A control means for giving a position command signal to each of the moving tables is provided, the workpiece and the processing tool are brought into contact with each other at a target contact point, and a processing apparatus capable of processing the workpiece while relatively moving the two is controlled. A method for rotating the rotary shaft by the shaft driving means, wherein an angle α around the X axis indicating an inclination of a central axis of the rotary shaft from an ideal rotation axis, an angle φ around the Y axis, and The angle θ around the Z axis is detected in advance according to the rotation speed of the rotary shaft, and the detected angles α, φ, and θ are used to make an actual contact point between the workpiece and the processing tool and a target. A method for controlling a processing apparatus, wherein table position data for each of the moving tables is corrected so that the contact points coincide with each other, and each of the moving tables is operated using the corrected table position data.