JP2002079451A - Grinder for non-complete round work piece - Google Patents

Abstract

PROBLEM TO BE SOLVED: To execute the grinding without the interference of a grinding face C adjacent to a grinding face B, and a wheel spindle stock 22 holding a small grinding wheel G2 by inclining a rotating axis of the small grinding wheel G2 to a main spindle axis, and to improve the grinding efficiency by executing the grinding by means of a large grinding wheel G1 and the small grinding wheel G2. SOLUTION: This grinder for a non-complete round work piece W having recessed parts on its outer peripheral face comprises the small grinding wheel G2 having a diameter capable of grinding the recessed parts, and the large grinding wheel G1 having a diameter larger than the small grinding wheel G2. The rotating axis of the small grinding wheel G2 is inclined to the main spindle axis supporting the non-complete round work piece W.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a non-circular workpiece grinding machine for processing a non-circular workpiece 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-circular workpiece such as a cam by controlling the feed of a grinding wheel in a direction intersecting with the axis of a spindle by a numerical controller in synchronization with the rotation of the spindle. . In recent years, the shape of the cam has become more complicated and more precise with the higher performance of the engine.
The demand for a cam W having a recess A as shown in FIG.

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

[0004]

However, as shown in FIG. 11, the outer peripheral surface Ga of the small-diameter grinding wheel is larger than the outer peripheral surface of the grinding wheel G on the main shaft side (front surface) of the grinding wheel base 1 which supports the grinding wheel G. When Ga is reduced to a diameter at which it retreats,
As shown in FIG. 11, when the cam W has a plurality of grinding points B and C, particularly where the maximum diameter of the non-round shape of the grinding points B and C is different on the circumference, the grinding points are determined. B
When grinding, the grinding wheel base interfered with the grinding location C, and it was difficult to grind a workpiece having the concave portion A.

[0005] Similarly, there is a possibility that the grinding wheel head 1 may interfere with the main spindle 2 supporting the non-circular workpiece W. Also,
In the grinding by the small-diameter grinding wheel G, the grinding efficiency was low because the peripheral speed of the grinding wheel was small, the grinding time was long, and the productivity was poor.

According to the present invention, when a cam having a concave portion A is ground by a grinding wheel G located at a position retracted from the front surface of the grinding wheel head 1, the grinding is performed without interfering with a grinding portion adjacent to the grinding wheel head 1. It is an object of the present invention to provide a non-circular workpiece grinding machine that can be used.

[0007]

According to a first aspect of the present invention, there is provided a spindle for supporting a non-circular workpiece having a concave portion on an outer peripheral surface, and a grinding wheel for grinding the outer peripheral surface. In a non-round work machine grinding machine equipped with control means for performing a generating motion based on profile data along the finished shape of the non-round work, the held wheel head and the wheel head and the spindle, The grindstone head comprises one grindstone wheel for holding a small-diameter grinding wheel having a diameter capable of grinding the concave portion, and the other grindstone wheel for holding a large-diameter grinding wheel having an outer diameter larger than that of the small-diameter grinding wheel. The grinding wheel shaft of the one grinding wheel stand is inclined with respect to the spindle axis.

Further, the invention of claim 2 provides a spindle supporting a non-circular workpiece having a concave portion on the outer peripheral surface, a grindstone table holding a grinding wheel for grinding the outer peripheral surface, the grindstone table and the spindle. In a non-round work grinding machine equipped with control means for performing a generating motion based on profile data along the finished shape of the non-round work, the grinding wheel base can grind the recess. A small-diameter grinding wheel having a large diameter and a large-diameter grinding wheel having an outer diameter larger than the small-diameter grinding wheel are provided, and a rotation axis of the small-diameter grinding wheel is inclined with respect to the main shaft axis.

[0009] The invention of claim 3 is based on claim 1 or 2.
Wherein the grinding surface of the small-diameter grinding wheel is formed in parallel with the outer peripheral surface of the non-round workpiece.

[0010] The invention of claim 4 is the first to third aspects of the present invention.
In the non-round workpiece grinding machine according to any one of the above, in causing the spindle and the grinding wheel head to perform a generating motion based on profile data along the finished shape of the non-round workpiece, the large diameter The grinding wheel performs rough grinding while leaving a margin for the finished shape, and the small-diameter grinding wheel performs finish grinding along the finished shape.

[0011] The invention of claim 5 provides the invention according to claims 1 to 3.
In the non-round workpiece grinding machine according to any one of the above, when grinding the outer periphery of the non-round workpiece, the small-diameter grinding wheel grinds only the concave portion.

[0012]

According to the first or second aspect of the present invention, the control means controls the main spindle and the grinding wheel head based on the profile data. At this time, the small-diameter grinding wheel comes into contact with the grinding surface of the non-round workpiece to be ground and performs the profile creation motion to perform the grinding, but the rotation axis of the small-diameter grinding wheel is inclined with respect to the main axis. Therefore, the wheel head holding the small-diameter grinding wheel does not interfere with other ground surfaces that are not currently ground. Therefore, a non-circular workpiece having a recess that can be ground only with a small-diameter grinding wheel without interfering with a grinding surface different from the grinding surface on which the grinding wheel head is currently grinding a non-circular workpiece. Can be performed. Further, the grinding process using the large-diameter grinding wheel and the small-diameter grinding wheel improves the grinding efficiency, the grinding time can be shortened, and the productivity is improved as compared with the grinding process using only the small-diameter grinding wheel.

According to the third aspect of the present invention, the grinding surface of the small-diameter grinding wheel is parallel to the outer peripheral surface of the non-circular workpiece to be ground, eliminating the need for traverse grinding, improving the grinding efficiency and shortening the grinding time. Can increase productivity.

According to the fourth aspect of the present invention, a large-diameter grinding wheel performs rough grinding while leaving a margin for the finished shape of a non-circular workpiece, and a small-diameter grinding wheel performs finish grinding along the finished shape. Therefore, the rough grinding of the large-diameter grinding wheel improves the grinding efficiency, shortens the grinding time, and improves the productivity.

According to the fifth aspect of the present invention, a portion other than the concave portion on the outer peripheral surface of the non-round workpiece is ground with a large-diameter grinding wheel, and the concave portion is ground with a small-diameter grinding wheel. Therefore, since only a concave portion of a non-circular workpiece is ground with a small-diameter grinding wheel having a low peripheral speed, the grinding efficiency is improved, the grinding time can be reduced, and the productivity is improved.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to specific embodiments. FIG. 1 is a configuration diagram showing a numerically controlled grinding machine.
Reference numeral 10 denotes a bed of a numerically controlled grinding machine, on which a work table 11 is slidably provided 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 parallel to the moving direction Z of the workpiece table 11, and the spindle 13 is rotated by the servomotor 14. .

A tailstock 15 is placed on the work table 11 at the right end thereof, and a center 16 of the tailstock 15 and the spindle 1 are mounted.
A non-circular workpiece W having grinding points B and C formed by a plurality of cams is sandwiched between the center 17 and the center W of the workpiece W. Is in agreement with the rotation phase of the main shaft 13.

Behind the bed 10, a work table 11 is provided.
The tool table 20 moving in parallel along is guided,
On this tool table 20, an orthogonal grinding wheel head 21 (coarse grinding wheel head) and an angular wheel head 22 that can advance and retreat along a tool feed axis (X axis) are guided in parallel. The tool table 20 is used for positioning the orthogonal grinding wheel table 21 and the angular grinding wheel table 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. It may not be necessary.

A large-diameter grinding wheel G1 and a small-diameter grinding wheel G2, which are rotationally driven by a motor 23 and a motor 24, respectively, are provided on the orthogonal wheel head 21 and the angular wheel head 22.
The orthogonal grinding wheel head 21 and the angular wheel head 22 are moved forward and backward by forward and reverse rotations of a servo motor 26 and a servo motor 27 via a feed screw 25. As shown in FIG. 1, the large-diameter grinding wheel G1 has a grinding wheel shaft 28 parallel to a spindle axis ZL connecting the spindle 13 and the tailstock 15.
Is supported by the orthogonal grinding wheel head 21 through the
1 is a large-diameter grindstone having an outer diameter protruding from the front surface 21a toward the workpiece.

Further, as shown in FIG. 1, the axis GL of the small-diameter grinding wheel G2 is a spindle axis Z connecting the spindle 13 and the tailstock 15.
The small-diameter grinding wheel G2 intersects the vertical plane passing through L, and is supported by a turntable 22a. The turntable 22a is rotatably mounted on the angular grindstone table 22, and is turned by a motor 22b. Further, as shown in FIG. 2, the small-diameter grinding wheel G2 is a small-diameter grinding wheel whose outer peripheral surface Ga is located rearward of an extension 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-circular workpiece W. In addition, small diameter grinding wheel G2
As shown in FIG. 2, the outer peripheral surface Ga is set closer to the non-circular workpiece W from the front surface 22c of the swivel base 22a in the X-axis direction due to the swivel of the swivel base 22a. On the other hand, the tool table 20 is connected to a servomotor 32 via a feed screw 31 and the workpiece table 11 is connected to the feed screw 3
6 is connected to the servomotor 34.

DSPX1 and DSPX2 are a first X-axis digital signal processor and a second X-axis digital signal processor for driving the servomotor 26 and the servomotor 27. 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 the digital servo unit 38 as shown in FIG.

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

The digital servo unit 29 receives a position command signal from the numerical controller 30 and transmits the input position command signal to a digital signal processor of a servomotor to be driven by the command signal, for example, a first X-axis digital signal processor DSPX1. Outputs the position command signal. When a position command signal is input to the first X-axis digital signal processor DSPX1, the first X-axis digital signal processor DSPX1 controls the servo motor 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. 26 is performed.

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

The numerical controller 30 mainly analyzes the machining cycle data and analyzes the orthogonal grinding wheel head 21 and the angular wheel head 2
2. A device that numerically controls the positions of the tool table 20, the work table 11 and the rotation of the main shaft 13 to control the grinding of the work W. The numerical controller 30 reads a content of a recording medium such as a magnetic disk, a magnetic tape, or a paper tape which stores ideal profile data and processing cycle data, and inputs 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 the like and a CRT display device 44 for displaying various information are connected.

As shown in FIG. 1, the numerical controller 30 includes a main CPU 37 for controlling the grinding machine, a ROM 33 for storing a control program, and an RA for storing input data and the like.
It is mainly composed of M39 and 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, and a workpiece mode setting area 32
5. A spark-out mode setting area 326 is provided.

Next, the operation will be described. FIG.
NC data including the processing cycle data shown in FIG. 3 is stored, and when a start button (not shown) on the keyboard 43 is pressed, the processing cycle data is started. 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 the NC data is read, and in the next step 102, it is determined whether or not the data is end. In the case of a data end, this program ends. If not, step 10
The process proceeds to 4 or less, and the code of the instruction word is determined. If it is determined in step 104 that the instruction word is a G code, a more detailed instruction code is determined.
The process of U37 proceeds to step 106. Step 1
In steps 06 to 120, the mode is set according to the instruction code. If it is determined in step 106 that the code is the G00 code, a flag is set in the fast forward mode area 323 in step 108, and the fast forward mode is set. If it is determined in step 110 that the code is the G01 code, 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.

If it is determined in step 114 that the code is the G04 code, 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. Step 1
If it is determined at step 18 that the code is a G51 code, step 12
At 0, a flag is set in the workpiece mode setting area 325, and the workpiece mode is set to the cam mode.

When the above mode setting is completed, the CPU 3
The process of No. 7 shifts to step 122, where the process described later is performed according to the NC data and the mode set in steps 106 to 120 described above. In step 122, it is determined whether the mode setting is the fast forward mode. If it is determined that the mode is the fast-forward mode, the process proceeds to step 124, where the movement code following the instruction code (in this embodiment,
The X1 code for moving the orthogonal wheel head 21, the X2 code for moving the angular wheel head 22, the Y code for moving the tool table 20, and the Z code for moving the work table 20). 22, the tool table 20, and the workpiece table 11 are moved.

If it is determined in step 122 that the current 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. If it is determined that there is an X code, the process proceeds to step 130, where the cam mode and the grinding feed mode (hereinafter referred to as "cam / grinding mode") are performed. ) Is determined.

At this time, in the cam / grinding mode and at step 126, it is determined that there is an X code, and when the X code is the movement code X1 for moving the orthogonal grinding wheel head 21,
In step 134, a pulse distribution for creating a cam is performed on the orthogonal grinding wheel head 21. In the cam / grinding mode and in step 133, it is determined that there is an X code.
Movement code X whose code moves on angular wheel head 22
If the number is 2, the pulse distribution for generating the cam is performed on the angular wheel head 22 in step 134.

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

The cam generation is executed according to the flowchart of FIG. First, in step 200, the read address I
Is set to 1. Next, in step 202, a pulse distribution completion signal is input from the drive CPU 36 to determine whether the pulse distribution in the previous cycle has been completed. If it is determined that the pulse distribution has been completed, the process proceeds to step 204, where the execution profile data D ( I) is read and step 206
It is determined whether or not the cut per spindle rotation has been completed. This determination is made based on numerical data specified 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. If the cutting per spindle rotation is not completed, in step 208, the cutting amount per unit angle is added to the read execution profile data D (I) to generate moving amount data. Positioning data, which is a combination of movement data and speed data, is output. If the cut per spindle rotation has been completed, in step 210, the execution profile data D (I) is directly used as the movement amount data.

Next, at step 214, it is determined whether or not the read address I is equal to or more than the end address Imax of the execution profile data. If I ≧ Imax, step 218
Then, the read address I is set to the initial value 1 to return to the top of the table, and the process proceeds to step 220. Otherwise, the read address I is updated by 1 in step 216 and the process returns to step 202.

At step 220, it is determined whether or not there is a Z code for moving the Z axis.
In step 222, the orthogonal grinding wheel head 21 or the angular grinding wheel head 22 is described behind the Z code by the movement amount indicated by the Z code to the + direction (right direction in FIG. 1) while performing the cam generating motion. The workpiece table 11 is fed on the basis of the R code (indicating the feed speed). Similarly, in step 223, the orthogonal grinding wheel head 21 or the angular wheel head 22 performs the cam generating motion and is indicated by the Z code. The work table 11 is fed in the minus direction (the left direction in FIG. 1) by the movement amount, and traverse grinding is performed.

If there is no Z code in step 220, the flow directly goes to step 224 to determine whether or not all cutting has been completed. This determination is made based on numerical data designated by the X code. If 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, the control of the grinding machine according to the processing cycle data shown in FIG. 6 will be described with reference to the flowcharts of FIGS. First, one cycle of the processing cycle data is decoded. Then, G0 of block NO10
The feed mode is set to the fast forward mode by the 0 code,
The orthogonal whetstone 2
1 will be positioned at the grinding position. The work mode is set to the cam mode by the G51 code described in the 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.
This is a rough grinding shape that leaves a margin for the finished shape of the non-circular workpiece W (corresponding to the alternate long and short dash line K in FIG. 7). The shape of the dashed line K in FIG. 7 is ground with 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 due to the presence of the X1 code. The F code indicates the grinding amount per one rotation of the spindle, and the R code indicates the grinding speed per one rotation of the spindle. The S code represents the spindle speed. In the NC data in FIG. 6, since the designated numerical values of the F code and the R code are equal, it is specified that the cutting is continuously performed at a constant speed with respect to the rotation of the main shaft.

Further, since a Z code is described in the block NO30, the feed speed described in the subsequent R code is written by the Z code every time the work table 11 rotates once by 20 (mm). To perform traverse grinding. Next, G04 of block NO40
The spark-out processing is performed by the dwell code of the cord according to the procedure shown in FIG. This flowchart roughly corresponds to the flowchart of FIG. 4, and is different in that the cut is not performed and the dwell process is stopped when the spindle is rotated a specified number of times.

Next, the mode is set to the rapid traverse mode by G00 of block NO50, and the orthogonal grinding wheel head 21 is returned by rapid traverse while performing a cam generating motion. Then, the angular grindstone base 22 is positioned at the grinding position by the Y code in the G00 code of the next block NO50. The workpiece mode is set to the cam mode by the G51 code of block NO60,
The execution profile data to be 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 table 22 performs cutting while performing a generating motion with respect to the rotation of the spindle. At this time, in the small-diameter grinding wheel G2, the axis GL intersects the main axis ZL, and the outer peripheral surface thereof is closer to the non-circular workpiece W than the front surface 22a of the angular grindstone table 22, as shown in FIG. Even if the small diameter grinding wheel G2 for grinding the concave portion of the cam W is used, the grinding can be performed without interfering with the adjacent grinding surface C.

Since a Z code is described in the block NO 70, traverse grinding is performed. Next, spark-out processing is performed in accordance with the procedure shown in FIG. 5 using the dwell code of the G04 code in block NO80. On the other hand, apart from this NC program, small diameter grinding wheel G
In order to change the contact point of the tip of No. 2, the motor 22b is controlled to rotate the grindstone head as needed.

As described above, the grinding wheel of the angular grinding wheel head has a large diameter, and the grinding wheel shaft of the angular grinding wheel head has a small diameter adapted to the shape of the concave portion of the cam for grinding the small diameter grinding wheel G2 of the angular grinding wheel head 22. Can be ground without interfering with the grinding surface C of the adjacent cam. Also, a rough cam shape is formed by the large-diameter grinding wheel G1 of the orthogonal grinding wheel head 21, and the cam is formed by two grinding wheels so as to form a finished shape including the concave portion by the small-diameter grinding wheel G2 of the angular grinding wheel head 22. By performing the grinding, the processing time can be reduced.

If it is not necessary to consider the processing time,
The grinding may be performed only with the small-diameter grinding wheel G2 having a small diameter corresponding to the shape of the concave portion. In this case, the orthogonal grinding wheel head 21 need not be provided. Alternatively, the portion other than the concave portion of the cam may be performed by the orthogonal wheelhead 21 using a grinding wheel having a large diameter, and only the shape of the concave portion may be partially ground.

Further, as shown in FIG. 8, the shape of the small-diameter grinding wheel G2 may be formed such that the grinding surface Ga is parallel to the cam surface.
In this case, there is no need to perform traverse grinding,
When the intersection angle between the main shaft axis and the grinding wheel axis becomes small (a sharp angle), the difference between the outer diameters at both ends of the small-diameter grinding wheel G2 becomes large, so that the cam surface when grinding is tapered. For this reason, when the taper of the cam surface at the time of this grinding becomes equal to or larger than the machining tolerance, the machining surface shown in FIG. 6 is used, and the cam surface becomes the maximum diameter of the outer diameter of the grinding wheel. The taper can be eliminated.

In addition, the grinding surface as shown in FIG. 9 may be formed in two steps to be used for roughing and finishing.

[Brief description of the 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 illustrating a processing procedure of a CPU.

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

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

FIG. 6 shows NC data for grinding a non-circular workpiece.

FIG. 7 is a diagram illustrating a grinding state of a non-circular workpiece;

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

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

FIG. 10 is an explanatory diagram of a grinding situation of a non-round workpiece having a concave portion.

FIG. 11 is an explanatory view of a conventional non-round workpiece grinding state.

[Explanation of symbols]

 Reference Signs List 10 Bed 11 Workpiece table 12 Spindlehead 13 Spindle 15 Tailstock 20 Grindstone table 21 Orthogonal grindstone table (coarse grinding wheelstone table) 22 Angular wheelstone table 30 Numerical control device G1 Large diameter grinding wheel G2 Small diameter grinding wheel W Workpiece

Claims (5)

[Claims] 1. A spindle for supporting a non-circular workpiece having a concave portion on an outer peripheral surface, a grindstone table holding a grinding wheel for grinding the outer peripheral surface, and a grindstone table and the main spindle are connected to the non-circular workpiece. In a non-circular workpiece grinding machine provided with a control means for performing a generating motion based on profile data along a finished shape of a workpiece, the grinding wheel table holds a small-diameter grinding wheel having a diameter capable of grinding the concave portion. One of the grinding wheels and the other grinding wheel holding a large-diameter grinding wheel having an outer diameter larger than that of the small-diameter grinding wheel, wherein the grinding wheel axis of the one of the grinding wheels is tilted with respect to the axis of the main spindle. Non-circular workpiece grinding machine characterized by the following. 2. A spindle for supporting a non-circular workpiece having a concave portion on an outer peripheral surface, a grindstone table holding a grinding wheel for grinding the outer peripheral surface, and a grindstone table and the main spindle are connected to the non-circular workpiece. In a non-circular workpiece grinding machine provided with control means for performing a generating motion based on profile data along the finished shape of the workpiece, the grinding wheel base has a small-diameter grinding wheel having a diameter capable of grinding the concave portion. A large diameter grinding wheel having an outer diameter larger than that of the small diameter grinding wheel, wherein a rotation axis of the small diameter grinding wheel is inclined with respect to the main axis. 3. The non-round work grinding machine according to claim 1, wherein a grinding surface of the small-diameter grinding wheel is formed in parallel with an outer peripheral surface of the non-round work. 4. The large-diameter grinding wheel has an allowance for the finished shape in causing the main spindle and the grinding wheel head to perform a generating motion based on profile data along the finished shape of the non-round workpiece. The non-round workpiece grinding machine according to any one of claims 1 to 3, wherein rough grinding is performed while leaving a small diameter, and finish grinding along the finished shape is performed in the small-diameter grinding wheel. 5. The non-round workpiece according to claim 1, wherein the small-diameter grinding wheel grinds only the recess when grinding the outer periphery of the non-round workpiece. Grinder.