JPH08243906A - Non-circular working grinder - Google Patents

Abstract

PURPOSE: To facilitate work of an untrue circular work by forming a grinding wheel as a small diameter grinding wheel capable of finishing grinding of a grinding surface, and forming a grinding wheel stand as an angular grinding wheel stand where one among plural non-circular grinding surfaces is set at a crossed axes angle of the grinding wheel axis and the main spindle axis of the grinding wheel noninterferening with the other grinding surface at grinding time. CONSTITUTION: A main spindle stand 13 and a tail stock 15 are placed on a work table 11, and an untrue circular work W is sandwiched by the center 16 of this tail stock 15 and the center 17 of a main spindle 13. A tool table 20 where an orthogonal grinding wheel stand 21 and an angular grinding wheel stand 22 are juxtaposed and guided, is arranged in the rear of a bed 10, and a large diameter grinding wheel G1 and a small diameter grinding wheel are supported with the respective grinding wheel stands 21 and 22. In this case, the axis GL of the small diameter grinding wheel is crossed with a perpendicular plane passing through the main spindle axis ZL, and the small diameter grinding wheel is brought into point contact with the small work W. The main spindle 13 and the angular grinding wheel stand 22 are controlled by a control means on the basis of profile data, and a profile is generated by the small grinding wheel.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a non-round work piece grinding machine for machining a non-round work piece such as a cam (hereinafter, also simply referred to as "cam").

[0002]

2. Description of the Related Art Conventionally, there has been known a method of grinding a non-round workpiece such as a cam by controlling the feed of a grinding wheel in a direction intersecting with a spindle axis by a numerical control device in synchronization with the spindle rotation. . In recent years, the shape of the cam has become complicated and highly accurate as the engine performance has been improved.
There is an increasing demand for a cam W having a recess A as shown in FIG.

When grinding a cam W having such a recess A, it is necessary to use a grinding wheel G having a small diameter capable of contacting the recess A.

[0004]

However, as shown in FIG. 11, the outer peripheral surface Ga of the small-diameter grinding wheel is closer to the outer peripheral surface of the grinding wheel G than the main spindle side surface (front surface) of the grinding wheel head 1 supporting the grinding wheel G. When the diameter becomes smaller so that Ga becomes the retracted position,
As shown in FIG. 11, the cam W has a plurality of grinding points B and C, and in particular, in the case where the positions of the non-round shape maximum diameters of the grinding points B and C are different on the circumference, B
The grinding wheel head interfered with the grinding point C when grinding the workpiece, and it was difficult to grind a workpiece having the recess A.

Further, similarly to this, there is a possibility that the grindstone base 1 interferes with the spindle 2 supporting the non-round work W. According to the present invention, the grinding wheel G located at the position retracted from the front surface of the grinding wheel head 1 grinds the cam having the recess A, but the grinding wheel head 1 can perform grinding without interfering with the adjacent grinding position. The object is to provide a circular work grinder.

[0006]

According to a first aspect of the invention for solving the above problems, the grinding wheel is a small diameter grinding wheel having a diameter capable of finishing grinding the grinding surface, and the grinding wheel head is provided with the plurality of grinding wheels. An angular grindstone base is provided in which one of the non-round-shaped grinding surfaces has an intersection angle between the grinding wheel axis of the grinding wheel and the spindle axis that does not interfere with another grinding surface during grinding.

According to a second aspect of the present invention, the outer peripheral surface of the small diameter grinding wheel has a circular shape, and the control means moves the small diameter grinding wheel and the non-round workpiece relative to each other in the axial direction of the spindle along with a generating motion. The traverse control means is provided. Further, in the invention of claim 3, a large-diameter grinding wheel having an outer diameter larger than that of the small-diameter grinding wheel held by the angular grinding wheel, and the large-diameter grinding wheel are rotatably held separately from the angular grinding wheel head. Rough grinding wheel head, a rough grinding control means for causing the spindle and the rough grinding wheel head to perform a generating motion based on profile data along a rough grinding shape of a non-round work, and the spindle and the angular wheel head. And a finishing control means for performing a creation motion based on the profile data along the finishing shape of the non-round work.

[0008]

According to the invention of claim 1, the control means controls the spindle and the angular grindstone based on the profile data, and the angular grindstone does not interfere with another grinding surface which is not currently being ground, and the angular grindstone does not interfere. A small-diameter grinding wheel mounted on the wheel head comes into contact with the grinding surface of the non-round work piece to be ground, and performs profile creation motion to perform grinding processing. In the invention of claim 2, the contact of the non-round work of the small diameter grinding wheel with the grinding surface becomes a point contact, and in this point contact state, the control means controls the spindle and the angular grindstone based on the profile data. , Small-diameter grinding wheel performs profile creation movement.

Along with this, the traverse control means relatively moves the angular grindstone head and the non-round work,
Profile creation and traverse grinding are performed simultaneously. According to the invention of claim 3, the rough grinding control means controls the spindle and the rough grinding wheel head based on the profile data of the rough grinding to perform the rough grinding of the non-round work. After that, the finish control means controls the spindle and the angular grindstone based on the finish profile data to perform finish grinding of the non-round work piece.

[0010]

EXAMPLES The present invention will be described below based on specific examples. FIG. 1 is a configuration diagram showing a numerical control grinding machine.
Reference numeral 10 denotes a bed of a numerically controlled grinding machine, on which a work table 11 is arranged slidably in the Z-axis direction. A headstock 12 on which a spindle 13 is mounted is arranged on the workpiece table 11, the axis ZL of the spindle is made parallel to the moving direction Z of the workpiece table 11, and the spindle 13 is rotated by a servomotor 14. .

A tailstock 15 is placed at the right end on the work table 11, and the center 16 of the tailstock 15 and the spindle 1 are mounted.
The non-round work W having the grinding points B and C composed of a plurality of cams is clamped by the center 17 of the three cams, and the work W is fitted to the positioning pin 18 projecting from the spindle 13, and the work W The rotation phase of is in agreement with the rotation phase of the main shaft 13.

A work table 11 is provided behind the bed 10.
A tool table 20 that moves in parallel along is guided,
An orthogonal grindstone head 21 (rough grinding grindstone head) and an angular grindstone head 22 capable of advancing and retreating along a tool feed axis (X axis) are guided in parallel to the tool table 20. The tool table 20 is used to position the orthogonal grindstone base 21 and the angular grindstone base 22 at the grinding position of the workpiece W. This positioning is performed by moving the workpiece table 11, and the tool table 20 is provided. You may not.

A large-diameter grinding wheel G1 and a small-diameter grinding wheel G2, which are rotatably driven by a motor 23 and a motor 24, are provided on the orthogonal grinding wheel base 21 and the angular grinding wheel base 22, respectively.
The orthogonal grindstone base 21 and the angular grindstone base 22 are moved forward and backward by the forward and reverse rotations of the servomotor 26 and the servomotor 27 via the feed screw 25. As shown in FIG. 1, the large-diameter grinding wheel G1 is parallel to the spindle axis ZL connecting the spindle 13 and the tailstock 15, and is parallel to the spindle 28 of the grinding wheel.
Is supported by the orthogonal grindstone base 21 through the
It is a large diameter grindstone having an outer diameter protruding from the front surface 21a of No. 1 toward the workpiece.

The axis line GL of the small-diameter grinding wheel G2 is a spindle axis line Z connecting the spindle 13 and the tailstock 15 as shown in FIG.
The small-diameter grinding wheel G2 intersects with the vertical plane passing through L, and is rotatably mounted on the swivel base 22a. The swivel base 22a is rotatably mounted on the angular grindstone base 22 and swung by the motor 22b. Further, as shown in FIG. 2, the small-diameter grinding wheel G2 is a small-diameter grinding stone whose outer peripheral surface Ga is located rearward of the extension line of the front surface 22c of the swivel base 22a, and the outer peripheral surface Ga has a radius R. It is formed in a circular shape.

As a result, the small diameter grinding wheel G2 comes into point contact with the non-round work W. In addition, small diameter grinding wheel G2
The outer peripheral surface Ga is set to be closer to the non-round work W as shown in FIG. 2 from the front surface 22c of the swivel base 22a in the X-axis direction by swiveling of the swivel base 22a. On the other hand, the tool table 20 is connected to the servomotor 32 via the feed screw 31, and the workpiece table 11 is connected to the feed screw 3.
It is coupled to the servomotor 34 via 6.

DSPX1 and DSPX2 are a first X-axis digital signal processor for driving the servo motor 26 and the servo motor 27, and a second X-axis digital signal processor. The first X-axis digital signal processor DSPX1 and the second X-axis digital signal processor DSPX2. Is connected to the numerical controller 30 via a digital servo unit 38 as shown in FIG.

Further, the Y-axis digital signal processors DSPY and Z are respectively provided to the servomotors 32, 34 and 35.
The rotation is controlled by the axis digital signal processor DSPZ and the main axis digital signal processor DSPC. The Z axis digital signal processor DSPZ and the main axis digital signal processor DSPC are connected to the numerical controller 30 via the digital servo unit 28, and the Y axis digital signal processor. The DSPY is connected to the numerical controller 30 via the digital servo unit 29.

The digital servo unit 29 inputs a position command signal from the numerical controller 30 and inputs the position command signal to a digital signal processor of the servomotor, for example, the first X-axis digital signal processor DSPX1 to be driven by the command signal. Outputs a position command signal. When the position command signal is input to the first X-axis digital signal processor DSPX1, the first X-axis digital signal processor DSPX1 causes the servo motor to operate based on the deviation between the position command signal and the feedback signal of the current position of the orthogonal grinding wheel head 21 from the encoder. The rotation control of 26 is performed.

The digital servo unit 29 and the second X-axis digital signal processor, Y-axis digital signal processor DSPY, Z-axis digital signal processor DSPZ, main-axis digital signal processor DS.
For PC, digital servo unit 38 and 1X
Since the function is the same as that of the axis digital signal processor DSPX1, the description is omitted.

The numerical control device 30 mainly analyzes the machining cycle data to analyze the orthogonal grinding wheel head 21 and the angular wheel head 2
2, a device for numerically controlling the positions of the tool table 20, the work table 11 and the rotation of the spindle 13 to control the grinding of the work W. This numerical control device 30 inputs a reading device 42 for reading the contents of a recording medium such as a magnetic disk, a magnetic tape, or a paper tape storing ideal profile data and processing cycle data, and data such as ideal profile data and processing cycle data. Also, a keyboard 43 for issuing a start command such as start of grinding and a CRT display device 44 for displaying various information are connected.

As shown in FIG. 1, the numerical controller 30 has a main CPU 37 for controlling the grinding machine, a ROM 33 storing a control program, and an RA storing input data and the like.
It is mainly composed of the M39 and the input / output interfaces 35 and 36. On the RAM 39, an NC data area 321 for storing NC data and an execution profile data area 322 for storing execution profile data determined from the finished shape of the workpiece W are provided. In addition, a rapid feed mode setting area 323 for setting various modes, a grinding feed mode setting area 324, a workpiece mode setting area 32
5. A spark-out mode setting area 326 is provided.

Next, the operation will be described. The RAM 39 is shown in FIG.
NC data including the machining cycle data shown in is stored, and the machining cycle data is activated when an unillustrated activation button of the keyboard 43 is pressed. These NC data are decoded by the CPU 31 according to the procedure shown in the flowchart of FIG.

In step 100, one block of NC data is read out, and in the next step 102, it is judged whether or not it is a data end. In case of data end, this program is terminated. If it is not the data end, step 10
After shifting to 4 or less, the code determination of the instruction word is performed. If it is determined in step 104 that the instruction word is a G code, CP is used to determine a more detailed instruction code.
The process of U37 proceeds to step 106. Step 1
At 06 to 120, mode setting is performed according to the instruction code. When it is determined to be the G00 code in step 106, the flag is set in the fast-forward mode area 323 in step 108, and the feed mode is set to the fast-forward mode. When it is determined to be the G01 code in step 110, a flag is set in the grinding feed mode setting area 324 in step 112, and the feed mode is set to the grinding feed mode.

When it is determined that the code is the G04 code in step 114, a flag is set in the spark-out mode setting area 326 in step 116, and the feed mode is set to the spark-out mode. Similarly, step 1
If it is determined to be G51 code in step 18, step 12
At 0, a flag is set in the work mode setting area 325, and the work mode is set to the cam mode.

When the above mode setting is completed, the CPU 3
The process of 7 shifts to step 122, and the process described later is performed according to the NC data and the mode set in steps 106 to 120 above. In step 122, it is determined whether or not the mode setting is the fast-forward mode. Then, when it is determined that the fast-forward mode is set, the process proceeds to step 124, and a movement code (in this embodiment, following the instruction code)
The X1 code for moving the orthogonal grinding wheel head 21, the X2 code for moving the angular grinding wheel head 22, the Y code for moving the tool table 20, and the Z code for moving the workpiece table) 22, the tool table 20, and the workpiece table 11 are moved.

If it is determined in step 122 that the mode is not the fast-forward mode, the process proceeds to step 126. In step 126, it is determined whether or not there is an X code in the read block, and if it is determined that there is an X code, the process proceeds to step 130 and the cam mode and the grinding feed mode (hereinafter referred to as "cam / grinding mode"). ) Or not is determined.

At this time, in the cam / grinding mode and when it is determined in step 126 that the X code is present, and the X code is the movement code X1 for moving the orthogonal grinding wheel base 21,
In step 134, pulse distribution for cam creation is performed on the orthogonal grinding wheel head 21. Further, in the cam / grinding mode, it is determined in step 133 that the X code is present, and the X
Movement code X where the code moves on the angular whetstone base 22
If it is 2, pulse distribution for cam creation is performed on the angular grindstone base 22 in step 134.

On the other hand, when the cam / grinding mode is not set, in step 132, pulse distribution not synchronized with normal rotation of the spindle 13 is performed. If it is determined in step 126 that there is no X code, the process proceeds to step 128 and it is determined whether the spark-out mode is set. If the spark-out mode is set here, the spark-out pulse is distributed in step 136, and if the spark-out mode is not set, step 10 is performed.
Return to 0.

The cam creation is executed according to the flowchart of FIG. First, in step 200, the read address I
The initial value of is set to 1. Next, in step 202, a pulse distribution completion signal is input from the drive CPU 36 to determine whether or not the pulse distribution in the previous cycle is completed. If it is determined to be complete, the process proceeds to step 204 and the execution profile data D ( I) is read and step 206
Then, it is determined whether or not the cutting per one rotation of the spindle has been completed. This judgment is made by the numerical data designated by the F code. In this case, the determination is made based on whether or not a cut of 0.1 mm has been made. When the cutting per spindle revolution has not been completed, the amount of cutting per unit angle is added to the read execution profile data D (I) in step 208 to generate movement amount data, and in step 212 the Positioning data, which is a combination of movement data and speed data, is output. When the cutting per revolution of the spindle has been completed, the execution profile data D (I) is used as the movement amount data as it is in step 210.

Next, at step 214, it is judged if the read address I is not less than the end address Imax of the execution profile data. When I ≧ Imax, step 218
Then, the read address I is set to the initial value 1 in order to return it to the head of the table and the process proceeds to step 220. If not, the read address I is updated by 1 in step 216 and the process returns to step 202.

At step 220, it is judged whether or not there is a Z code for moving the Z axis. If there is a Z code,
After shifting to step 222, the orthogonal grindstone head 21 or the angular grindstone head 22 is described behind the Z code up to the + direction (to the right in FIG. 1) by the movement amount indicated by the Z code while performing the cam generating motion. The workpiece table 11 is fed on the basis of the R code (indicating the feed rate) which is being given, and similarly, in step 223, the orthogonal grindstone head 21 or the angular grindstone head 22 is indicated by the Z code while performing the cam generating motion. Only by the amount of movement, the work table 11 is fed in the negative direction (leftward in FIG. 1) and traverse grinding is performed.

When there is no Z code in step 220, the process directly goes to step 224 and it is determined whether or not all the cuts have been completed. This determination is made based on numerical data designated by the X code. When all the cuts have not been completed, the process proceeds to step 202 and proceeds to the next control cycle. On the other hand, when all the cuts have been completed, the cam grinding process is completed.

Here, control of the grinding machine according to the machining cycle data shown in FIG. 6 will be described with reference to the flowcharts of FIGS. First, one cycle of machining cycle data is decoded. Then, G0 of block NO10
The feed mode is set to the fast feed mode by the 0 code,
Orthogonal grinding wheel head 2 by the Y code of this block NO10
1 is positioned at the grinding position. Then, the workpiece mode is set to the cam mode by the G51 code described in block NO20, and the execution profile data to be used is designated by the number P1234.

Here, the execution profile data indicated by the number P1234 is for grinding the shape shown by the solid line J in FIG. 7, and the shape shown by this solid line J is
It is a rough grinding shape with a machining allowance left with respect to the finished shape of the non-round work W (corresponding to the one-dot chain line K in FIG. 7). The shape of the alternate long and short dash line K in FIG. 7 is ground by the execution profile data indicated by the number P5678.

The grinding feed mode is set by the G01 code of the next block NO30, and the cam grinding process is performed by X-0.1 by the existence of the X1 code. The F code is the grinding amount per one rotation of the spindle, and the R code is the grinding speed per one rotation of the spindle. The S code represents the spindle rotation speed. In the NC data of FIG. 6, since the designated values of the F code and the R code are the same, it is designated to continuously cut at a constant speed with respect to the rotation of the spindle.

Further, since the Z code is written in this block NO30, the feed rate written in the R code that follows each time the work table 11 rotates by 20 (mm) by this Z code. Is reciprocated and traverse grinding is performed. Next, G04 of block NO40
Spark out processing is performed by the procedure shown in FIG. 5 by the dwell code of the code. This flowchart is substantially the same as the flowchart in FIG. 4, and is different in that the cutting is not performed and the dwell process is stopped when the main shaft rotates a designated number of times.

Next, the fast-forward mode is set by G00 of block NO50, and the orthogonal grinding wheel head 21 is returned by fast-forward while performing the cam generating motion. Then, the angular grindstone base 22 is positioned at the grinding position by the G00 code and the Y code of the next block NO50. Then, the workpiece mode is set to the cam mode by the G51 code of block NO60, and
The execution profile data used is designated by the number P5678.

In block NO70, the grinding feed mode is set by the G01 code, and it is specified that the angular grindstone base 22 makes a cut while making a generating motion with respect to the rotation of the spindle. At this time, the axis GL of the small-diameter grinding wheel G2 intersects the spindle axis ZL, and the outer peripheral surface of the small-diameter grinding wheel G2 is closer to the non-round work W than the front surface 22a of the angular grindstone base 22. Therefore, as shown in FIG. Even if a small diameter grinding wheel G2 with a small diameter that grinds the concave portion of the cam W is used, grinding can be performed without interfering with the adjacent grinding surface C.

Further, since the Z code is written in this block NO70, traverse grinding is performed. Next, spark-out processing is processed by the procedure shown in FIG. 5 by the dwell code of the G04 code of block NO80. On the other hand, in addition to this NC program, small diameter grinding wheel G
In order to change the hitting point of the tip of No. 2, the motor 22b is controlled to rotate the grindstone as needed.

As described above, the grinding wheel of the orthogonal grinding wheel head has a large diameter, and the grinding wheel shaft of the angular grinding wheel head has a small diameter corresponding to the shape of the recess of the cam for grinding the small diameter grinding wheel G2 of the angular grinding wheel head 22. By inclining with respect to the main axis, the recess can be ground without interfering with the grinding surface C of the adjacent cam. In addition, the large-diameter grinding wheel G1 of the orthogonal grinding wheel base 21 forms a rough cam shape, and the small-diameter grinding wheel G2 of the angular grinding wheel base 22 forms a finishing shape including recesses so that the two grinding wheels form a cam. By performing the grinding process, the processing time can be shortened.

If it is not necessary to consider the processing time,
Grinding may be performed only with a small diameter grinding wheel G2 having a small diameter that matches the shape of the recess, and in this case, it is not necessary to provide the orthogonal grinding wheel base 21. Alternatively, the parts other than the concave part of the cam may be formed by the orthogonal grinding wheel base 21 using a grinding wheel having a large diameter, and only the shape of the concave part may be partially ground.

Further, the shape of the small diameter grinding wheel G2 may be formed such that the grinding surface Ga is parallel to the cam surface as shown in FIG.
In this case, it is not necessary to perform traverse grinding,
When the intersecting angle between the spindle axis and the grindstone axis becomes small (a sharp angle), the difference between the outer diameters of both ends of the small diameter grinding wheel G2 becomes large, so that the cam surface at the time of grinding becomes tapered. For this reason, when the taper of the cam surface after this grinding exceeds the machining tolerance, the machining program of FIG. 6 is performed so that the cam surface has the shape of the maximum outer diameter of the grinding wheel, The taper can be eliminated.

In addition to this, two grinding surfaces as shown in FIG. 9 may be used for roughing and finishing.

[0044]

As described above, according to the first aspect of the invention, the grinding wheel is a small diameter grinding wheel having a diameter capable of finishing grinding the grinding surface, and the grinding wheel head is composed of the plurality of non-round grinding surfaces. One of them is an angular grindstone that has a crossing angle between the grindstone axis of the grinding wheel and the spindle axis that does not interfere with the other grinding surface during grinding. It is possible to process a non-round work piece having a concave portion that can be ground only by a small diameter grinding wheel without interfering with a grinding surface different from the grinding surface being processed.

According to a second aspect of the present invention, the outer peripheral surface of the small diameter grinding wheel is made circular, and the control means makes the small diameter grinding wheel and the non-round work relative to each other in the axial direction of the spindle. If the traverse control means for moving is provided, the contact point between the grinding surface of the non-round workpiece and the outer peripheral surface of the small diameter grinding wheel is 1
It becomes a point, and it is possible to perform grinding without changing the outer diameter at both ends of the grinding surface of the non-round work.

In addition to the above-mentioned angular grinding table, a rough grinding wheel table in which a large-diameter wheel having an outer diameter larger than that of the small wheel held in the angular wheel table is rotatably held is used. By performing rough grinding with the grinding wheel head and performing the finishing motion by causing the angular wheel head to perform the creation motion according to the finish shape of the non-round work piece, the grinding efficiency can be improved and the grinding time can be shortened. it can.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a numerically controlled grinding machine according to an embodiment of the present invention.

FIG. 2 is an enlarged view of a portion related to the gist of the present invention.

FIG. 3 is a flowchart showing a processing procedure of a CPU.

FIG. 4 is a flowchart showing a processing procedure of a CPU.

FIG. 5 is a flowchart showing a processing procedure of a CPU.

FIG. 6 is NC data for grinding a non-round work piece.

FIG. 7 is a diagram illustrating a grinding state of a non-round work piece.

FIG. 8 is a view showing the shape of a grinding wheel according to another embodiment.

FIG. 9 is a view showing the shape of a grinding wheel according to another embodiment.

FIG. 10 is an explanatory diagram of a grinding state of a non-round work having a recess.

FIG. 11 is an explanatory diagram of a grinding situation of a conventional non-round work piece.

[Explanation of symbols]

 10 bed 11 work table 12 spindle head 13 spindle 15 tailstock 20 grindstone table 21 orthogonal grindstone (coarse grinding stone head) 22 angular grindstone 30 numerical control device G1 large diameter grinding wheel G2 small diameter grinding wheel W workpiece

Claims (3)

[Claims] 1. A spindle for supporting a non-round work having a plurality of non-round grinding surfaces, a wheel head for holding a grinding wheel,
In the non-round workpiece grinder equipped with a control means for causing the spindle and the grinding wheel head to perform a generating motion based on the profile data along the finishing shape of the non-round workpiece, in the non-round workpiece grinding machine, the grinding wheel finishes the grinding surface. As a small diameter grinding wheel with a diameter that can be ground,
One of the plurality of non-round grinding surfaces
A non-round work grinder, characterized in that it is an angular grindstone having a crossing angle between a grindstone axis of the grinding wheel and the spindle axis which does not interfere with another grinding surface during grinding. 2. The outer peripheral surface of the small-diameter grinding wheel has a circular shape, and the control means is provided with traverse control means for relatively moving the small-diameter grinding wheel and the non-round work together in the spindle axis direction with the creation motion. The non-round workpiece grinder according to claim 1. 3. A large-diameter grinding wheel having an outer diameter larger than that of a small-diameter grinding wheel held by the angular grinding wheel head, separately from the angular grinding wheel head, and a rough grinding wheel having the large-diameter grinding wheel rotatably held. A rough grinding control means for causing the table, the spindle and the rough grinding wheel head to perform a generating motion based on profile data along a rough grinding shape of a non-circular workpiece, and the spindle and the angular wheel head are non-true. The non-round work grinding machine according to claim 1 or 2, further comprising: finish control means for performing a generating motion based on profile data along a finish shape of the circular work.