Cylinder grinding method and grinding machine

Abstract

To simply grind a cylindrical surface of workpiece around a work center, even though the work center is decentered from a circle table center.SOLUTION: A cylinder grinding method includes: installing a disk-like workpiece 3 having first and second singular points 3a and 3b on a circular table 35 rotated around a table center 38; allowing an imaging machine 31 to acquire first and second singular point images 5a and 5b; determining an eccentric position q3 which is a coordinate of the work center 3c from the table center 38, on the basis of a position u2 of the first singular point 3a in the first singular point image 5a, a position u3 of the second singular point 3b in the second singular point image 5b, and a display magnification f; moving a main shaft 27 mounted with a rotary grinding wheel 1a; and cylindrically grinding the outer periphery of workpiece 3, on the basis of the eccentric position q3 and the rotation angle of the circular table 35.SELECTED DRAWING: Figure 6

Description

Technical Field

[0001] The present invention relates to a cylindrical grinding method and a grinding machine tool.

Background Art

[0002] A grinding center in which the functions of a grinding machine tool are integrated with a machining center as a base is known. Also, a method of cylindrically grinding the crank pin of a crankshaft with reference to the journal center is known (Japanese Patent Application Laid-Open No. 11-90799).

Summary of the Invention

Problems to be Solved by the Invention

[0003] The present invention provides a method for easily grinding the cylindrical surface of a workpiece around the workpiece center even when the workpiece center is eccentric from the center of a circular table by using a grinding center having a circular table.

Means for Solving the Problems

[0004] A first aspect of the present invention is placing a disk-shaped workpiece having a workpiece center, a first singular point, and a second singular point on a circular table that rotates about a table center, rotating the circular table to place the first singular point within the viewing angle of an imaging device, and the imaging device obtaining a first singular point image including the first singular point, rotating the circular table by a predetermined angle, and the imaging device obtaining a second singular point image including the second singular point, determining an eccentricity position, which is the coordinates of the workpiece center from the table center, based on the position of the first singular point in the first singular point image, the position of the second singular point in the second singular point image, and a display magnification that is the ratio of the dimensions in the real space to the displayed dimensions of the viewing angle, rotating the circular table and moving a tool spindle equipped with a rotary grinding wheel, and cylindrically grinding the outer periphery of the workpiece around the workpiece center based on the eccentricity position and the rotation angle of the circular table. It is a cylindrical grinding method.

[0005] The second aspect of the present invention is a grinding machine for grinding a workpiece, a gantry, a processing chamber, a measurement chamber having an imaging device for imaging the workpiece therein, a partition wall partitioning the processing chamber and the measurement chamber, an opening, a door for opening and closing the opening, a partition wall having the above, a gantry having the above, a circular table on which the workpiece is installed and is movably arranged in the front - rear direction on the gantry, and when the door is opened, at the moving end, at least a part of the workpiece can move into the measurement chamber through the opening, a tool spindle arranged in the processing chamber and movable in the left - right and up - down directions, a grinding machine having the above.

[0006] The workpiece is, for example, a ceramic wafer, an electrostatic chuck. The first singularity and the second singularity are singularities of a circuit or an electrode formed on the workpiece. The first singularity and the second singularity are alignment marks, electrode marks, or other reference marks. The first singularity and the second singularity are rectangular, circular, linear, semi - circular, or a combination thereof. For example, the first singularity and the second singularity are L - shaped. The reference mark may include a reference line. Preferably, the reference marks are arranged n - fold rotationally symmetric about the center of the workpiece.

[0007] For example, a chuck is arranged on the circular table. The chuck is, for example, a vacuum chuck. The workpiece is fixed to the circular table by the chuck. Preferably, the grinding machine is numerically controlled.

[0008] The measurement reference position, which is the coordinate from the center of the table of the measurement reference that moves together with the circular table, may be measured by a tool spindle equipped with a touch probe.

[0009] The eccentric position of the workpiece, the position of the first singularity point, and the position of the second singularity point are vector quantities in a plane perpendicular to the tool spindle. The eccentric position of the workpiece, the position of the first singularity point, and the position of the second singularity point have, for example, values in the left-right direction (X coordinate), the front-back direction (Y coordinate), and the C coordinate. The C coordinate is a rotational coordinate around the vertical axis of the table.

[0010] The circular table may be imaged by an imaging device to determine the reference position of the viewing angle from the center of the table.

[0011] The first table position when acquiring the measurement reference image may be obtained. Also, the second table position when acquiring the first singularity point image and the second singularity point image may be obtained.

[0012] Desirably, the viewing angle is adjusted to a rectangle. The circular table may be moved by a predetermined amount to determine the inclination with respect to the left-right direction and the front-back direction of the viewing angle. The circular table may be moved in the left-right direction to adjust the left-right direction of the viewing angle parallel to the moving direction of the circular table in the left-right direction. The arrangement direction of the pixels may be parallel or perpendicular to the moving direction of the circular table in the front-back direction or the left-right direction. When the viewing angle is inclined with respect to the circular table or the moving direction of the table, the coordinates and positions of the first singularity point image, the second singularity point image, and the reference image may be linearly transformed to determine the coordinates in the real space. The linear transformation is, for example, a coordinate rotation. At this time, the coordinates in the first singularity point image, the second singularity point image, and the reference image may be enlarged or reduced by the display magnification to determine the coordinates in the real space. Also, the circular table may be photographed. At this time, the reference position of the viewing angle may be determined from the coordinates of the circular table at the time of photographing and the position of the circular table within the viewing angle.

[0013] When the circular table is moved by a predetermined amount, the display magnification on the picture angle may be determined from the amount of movement of the circular table within the picture angle. Also, an object of a reference size arranged on the circular table may be imaged to determine the display magnification on the picture angle. The distance per pixel within the picture angle may be determined. Based on the distance per pixel and the display magnification, the coordinates of the photographed object may be determined. Coordinates may be read as position. Position may be read as coordinates.

[0014] The measurement reference is, for example, a reference part of the circular table or a reference pin arranged on the side of the circular table.

[0015] The machining of the work reference may be carried out after cylindrical grinding. The work reference is, for example, an orientation flat or a notch. The work reference may be machined by grinding or cutting. After the cylindrical grinding of the work, holes or grooves may be ground or cut in the work.

[0016] The grinding device may be fixed inside the measurement chamber and may have an imaging frame for fixing the imaging camera. The grinding machine may have a dressing tool table instead of a dressing spindle. A stationary dresser is mounted on the dressing tool table.

Advantages of the Invention

[0017] According to the present invention, even when the work center is eccentric from the center of the circular table, the cylindrical surface of the work can be easily ground around the work center by using a grinding center having a circular table.

Brief Description of the Drawings

[0018]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Figure 12

Mode for Carrying Out the Invention

[0019] <Embodiment 1> As shown in FIG. 1, the grinding machine 10 of the present embodiment includes a gantry 11, a column 23, a spindle head 25, a spindle 27, an X bellows 28, a table 19, a tool changer 29, a Y bellows 21, a door 17, a camera 31, an imaging frame 32, and a lighting fixture 33. When the grinding machine 10 is viewed from the front, the left - right direction is referred to as the X direction (X - axis). The front - rear direction is referred to as the Y direction (Y - axis). The up - down direction is referred to as the Z direction (Z - axis).

[0020] The gantry 11 includes a machining chamber 13, a measurement chamber 14, and a partition wall 15. The partition wall 15 has an opening 16. The partition wall 15 divides the inside of the gantry 11 into a machining chamber 13 and a measurement chamber 14. The door 17 is, for example, an up - down sliding door. The door 17 is disposed on the partition wall 15 and opens and closes the opening 16. When the door 17 is closed, the machining chamber 13 is substantially sealed. Substantially sealed means that the door covers 95% or more of the area of the opening 16.

[0021] The grinding machine 10 has a Y guide (not shown) and a Y drive device (not shown). The Y guide and the Y drive device extend in the Y direction. The Y guide and the Y drive device are arranged on the gantry 11. The table 19 is arranged on the Y guide. The table 19 reciprocates in the Y direction by the Y drive device. The Y bellows 21 covers the Y guide and the Y drive device.

[0022] The grinding machine 10 has an X guide (not shown) and an X drive device (not shown). The column 23 is in a portal shape. The column 23 is fixed to the machining chamber 13. The X guide and the X drive device extend in the X direction. The X guide and the X drive device are arranged at the upper part of the column 23. The spindle head 25 is arranged on the X guide. The spindle head 25 reciprocates in the X direction by the X drive device. The X bellows 28 covers the X guide and the X drive device.

[0023] The spindle head 25 moves in the vertical, horizontal, and lateral directions. The spindle head 25 rotatably supports a spindle (tool spindle) 27. The spindle head 25 and the spindle 27 extend in the Z direction. The spindle 27 rotates around the Z axis.

[0024] The tool changer 29 is arranged, for example, below the column 23. The tool changer 29 holds a plurality of tools 1. The tools 1 are, for example, a rotary grinding wheel 1a, a touch probe 1b, and a cutting tool 1c. The tool changer 29 exchanges the tool 1 attached to the spindle 27.

[0025] The imaging frame 32 is, for example, in a portal shape. The imaging frame 32 is arranged in the measurement chamber 14. The camera 31 is fixed to the imaging frame 32. The camera 31 has an angle of view 5 (see FIG. 4). The camera 31 acquires a measurement reference image 5c (see FIG. 4), a first singular point image 5a (see FIG. 5), and a second singular point image 5b (see FIG. 6). The camera 31 is arranged above the workpiece. The lighting fixture 33 is fixed to the gantry 11. The lighting fixture 33 is arranged inside the measurement chamber 14. When the workpiece is transparent or translucent, the lighting fixture 33 may be arranged on the lower surface of the workpiece 3. When the camera 31 photographs the workpiece 3 (see FIG. 5), the lighting fixture 33 illuminates the workpiece 3.

[0026] As shown in FIG. 2, the table 19 has a circular table 35, a chuck 37, a measurement reference 39, an optical tool measuring instrument 41, and a dresser spindle 43. The circular table 35 rotates about the table center 38. The chuck 37 is, for example, a vacuum chuck or an electrostatic chuck. The chuck 37 is arranged coaxially with the circular table 35. The chuck 37 supports the workpiece 3 on the circular table 35. The measurement reference 39 is a straight circular cylinder having the reference center 40 as the central axis. The dresser spindle 43 rotates at high speed. A rotary dresser (rotary grinding wheel) 6 shown in FIG. 9 is attached to the dresser spindle 43. The optical tool measuring instrument 41 has an optical axis 42. Note that the measurement reference 39 may be arranged on the circular table 35. The measurement reference 39 may be rectangular or semi-circular.

[0027] As shown in FIGS. 5 and 6, the workpiece 3 has a first singular point 3a, a second singular point 3b, and a workpiece center 3c. The workpiece 3 is, for example, disk-shaped. The first singular point 3a has a center 3a1 and a reference line 3a2. The center 3a1 is, for example, the centroid of the first singular point 3a or the geometric center of the first singular point 3a. The reference line 3a2 is a straight line serving as a reference for the first singular point 3a. For example, when the first singular point 3a is rectangular, the side of the first singular point 3a extending in the circumferential direction of the workpiece 3 is taken as the reference line 3a2.

[0028] The second singular point 3b is arranged symmetrically with respect to the workpiece center 3c and the first singular point 3a in a two-fold rotational symmetry. The second singular point 3b has a center 3b1. Note that when the singular point is rotationally symmetric by n times, the calculation methods of the phase and the eccentricity position q3 (see FIG. 6) can be appropriately modified and executed according to n.

[0029] As shown in FIG. 1, the grinding machine 10 has a control device 12. The control device 12 includes a storage device and an arithmetic unit. The control device 12 has a numerical control function. The storage device stores, for example, various images, coordinates, information on the workpiece 3, and control parameters. The arithmetic unit has, for example, an image processing function, an eccentricity position calculation function, and a numerical control function. The control device 12 numerically controls the spindle head 25, the spindle 27, the table 19, the circular table 35, the dressing spindle 43, and the tool changer 29. As shown in FIGS. 4 to 8, the control device 12 acquires the XYZC coordinates of the spindle 27 and the circular table 35 with respect to the machine origin 49 (see FIG. 5) and the table center 38. The coordinate value px (x is a subscript) based on the machine origin 49 is called the machine coordinate. The coordinate value qx (x is a subscript) based on the table center 38 is called the table coordinate. The control device 12 can acquire the coordinates of each part in the imaging angle 5 from the imaging angle reference 5d.

[0030] Further, the control device 12 can extract the contour of the shape of the object shown in the captured image. The control device 12 calculates the coordinates of the object captured in the imaging angle 5 in the real space from the coordinates within the imaging angle 5. The control device 12 may calculate the coordinates of the object or the contour from the extracted contour. The coordinate value ux (x is a subscript) based on the imaging angle reference 5d on the imaging angle 5 is called the imaging angle coordinate. The coordinate value rx (x is a subscript) based on the position of the imaging angle reference 5d in the real space is called the real imaging angle coordinate. The coordinate values px, qx, rx, and ux are represented by vectors (bold italic).

[0031] As shown in FIG. 3, the grinding method of this embodiment has the following steps. First, in step S1, an operator or a transporter (not shown) installs the workpiece 3 on the circular table 35. Then, the chuck 37 clamps the workpiece 3. In step S2, the table 19 moves. In step S3, the angle of view 5 (see FIG. 4) is adjusted. In step S4, the table 19 is moved. In step S5, the eccentric position q3 of the workpiece 3 is measured. In step S6, the table 19 is moved and the table 19 is put into the processing chamber 13. In step S7, the door 17 is closed. In step S8, the outer cylindrical surface of the workpiece 3 and the workpiece reference are ground by the main shaft 27 equipped with the rotary grinding wheel 1a. In step S9, the workpiece 3 is cut by the main shaft 27 equipped with the cutting tool 1c. In step S10, the door 17 is opened. In step S11, the table 19 is moved in the direction (-Y direction) of the measurement chamber 14. Finally, in step S12, the chuck 37 unclamps the workpiece 3. The operator or the transporter (not shown) removes the workpiece 3 from the circular table 35.

[0032] Preferably, steps S2 and S3 are executed every time. Steps S2 and S3 may be performed only once every several times. Steps S2 and S3 may be executed once every time a certain period of time has elapsed. Step S9 may be omitted.

[0033] As shown in FIG. 4, in step S2, the control device 12 moves the table 19 so as to accommodate the measurement reference 39 within the angle of view 5. At this time, a part of the table 19 moves into the measurement chamber 14 beyond the partition wall 15. Most of the table 19 may remain in the processing chamber 13.

[0034] Referring to FIG. 4, step S3 will be described. FIG. 4 shows a plan view of a state in which the measurement reference 39 is accommodated within the angle of view 5 of the camera 31. The angle of view 5 has an angle-of-view reference 5d, a side 5e, and a side 5f. The control device 12 adjusts so that the shape of the viewing angle 5 becomes rectangular. The control device 12 can adjust so that the side 5f becomes perpendicular to the side 5e. The control device 12 images the video of the viewing angle 5 and obtains the measurement reference image 5c. Then, as represented by the arrows 51 and 52, the circular table 35 is moved along the Y-axis. As represented by the arrows 53 and 54, in the viewing angle 5, the measurement reference 39 moves to the two-dot chain lines 39a and 39b. The control device 12 adjusts the viewing angle 5 so that the movement locus of the measurement reference 39 follows the side 5e of the viewing angle 5 or the pixel array. The angle of the viewing angle 5 may be adjusted on software by image conversion. The angle of the viewing angle 5 may be adjusted mechanically. The display magnification f is a scalar quantity. When the actual movement amount is s2 and the movement amount on the viewing angle 5 is s3, the display magnification f is obtained by f = s2 / s3. Note that in step S3, the workpiece 3 may be fixed to the circular table 35. Also, when the circular table 35 can move in the X direction, the control device 12 may move the circular table 35 and adjust the inclination of the side 5f so that the movement locus of the measurement reference 39 becomes parallel to the X direction.

[0035] As shown in FIG. 5, in step S4, the control device 12 moves the table 19 in the Y direction so that the first singular point 3a is within the viewing angle 5. At this time, the table 19 may be moved so that the outer periphery of the workpiece 3 is within the viewing angle 5. Preferably, the control device 12 rotates the circular table 35 so that the first singular point 3a is at the center of the viewing angle 5. The control device 12 may rotate the circular table 35 so that the reference line 3a2 is the same as the side 5f. Let the C-axis coordinate of the machine coordinate p2 of the circular table 35 at this time be c1.

[0036] Referring to FIGS. 5 and 6, step S5 will be described. The camera 31 captures the viewing angle 5 and obtains the first singular point image 5a. The control device 12 determines the first singular point position u2, which is the coordinate of the center 3a1 in the first singular point image 5a. For example, the control device 12 extracts the four sides of the first singular point 3a and sets the coordinate of the intersection point of the two straight lines connecting the intersection points of the diagonals of the four sides as the first singular point position u2. The control device 12 multiplies the first singular point position u2 by the display magnification f to obtain the first singular point position r2 in the real space. The control device 12 determines the first singular point position q1, which is the table coordinate of the first singular point 3a, according to the following formula.

[0037] TIFF2025092101000002.tif12156 Here, q1: Table coordinate (first singular point position) of the center 3a1 of the first singular point 3a q5: Table coordinate (reference position) of the viewing angle reference 5d r2: Position of the center 3a1 with respect to the viewing angle reference 5d in the real space f: Display magnification u2: Position of the center 3a1 with respect to the viewing angle reference 5d in the first singular point image 5a That is.

[0038] Subsequently, the control device 12 rotates the circular table 35 by 180 degrees. Then, the camera 31 captures the viewing angle 5 and obtains the second singular point image 5b. The control device 12 determines the second singular point position q2 and the eccentricity position q3 according to the following formula. The method for determining the second singular point position q2 is substantially the same as the method for determining the first singular point position q1. The eccentricity position q3 is the table coordinate of the workpiece center 3c.

[0039] TIFF2025092101000003.tif33168 Here, q2: Table coordinate (second singular point position) of the center 3b1 of the second singular point 3b r3: Position of the center 3b1 with respect to the viewing angle reference 5d in the real space u3: Position of the center 3b1 with respect to the viewing angle reference 5d in the second singular point image 5b q3: Table coordinate (eccentricity position) of the workpiece center 3c That is.

[0040] In step S6, the control device 12 moves the table 19 so that the table 19 is completely received in the processing chamber 13. After step S7, the measurement chamber 14 is substantially blocked from the processing chamber 13.

[0041] Referring to FIG. 7, step S8 will be described. The tool changer 29 attaches the rotary grinder 1a to the spindle 27. Next, the spindle 27 rotates. Based on the eccentric position q3, the control device 12 rotates the circular table 35 and cylindrically grinds the workpiece 3 with the rotary grinder 1a around the workpiece center 3c. Specifically, with the table center 38 as the origin, the position of the rotary grinder 1a is expressed as follows.

[0042] TIFF2025092101000004.tif19134 Here, Kx: Finishing radius of the workpiece 3 + radius of the grinder 1a R: Length of the vector q3 (eccentric amount) θ: Rotation angle of the circular table 35 from the position where the center of the grinder 1a, the workpiece center 3c, and the table center 38 are in a straight line Δr: Grinding allowance (radius) n: Number of rotations of the workpiece 3 while removing the grinding allowance Δr That is. To determine the grinding allowance Δr, a touch probe 1b may be attached to the spindle 27, and the outer diameter of the workpiece 3 before grinding may be measured by the spindle 27.

[0043] As shown in FIG. 8, in step S8, after the workpiece 3 is cylindrically ground, an orientation flat 3d may be ground on the workpiece 3. The circular table 35 is indexed to C = c1. Then, the reference line 3a2 of the first singularity 3a becomes parallel to the X axis. In this state, while reciprocating the rotary grinder 1a in the X direction, a cut is made in the Y direction until the distance in the Y direction from the workpiece center 3c becomes 3e.

[0044] In step S9, a cutting tool 1c such as a drill is attached to the main spindle 27. Then, the main spindle 27 is rotated, and grinding or cutting is performed on the workpiece 3 using the cutting tool 1c.

[0045] In step S11, the control device 12 moves the table 19 to the workpiece installation position (not shown). The workpiece installation position is, for example, the -Y direction end of the stroke of the table 19. At the workpiece installation position, a part of the circular table 35 and the workpiece 3 is inside the measurement chamber 14.

[0046] In step S1 or step S11, the workpiece 3 may be transferred between a transporter (not shown) and the circular table 35. An operator or the transporter may install the workpiece 3 on the circular table 35 in a specific position and posture. The transporter is, for example, an articulated robot, an automated guided vehicle, or a mobile robot.

[0047] Note that instead of step S3, the control device 12 may calculate the vectors r2 and r3 in the real space by linearly transforming the vectors u2 and u3 on the drawing angle 5.

[0048] Referring to FIG. 9, a method for truing or dressing the rotary grinding wheel 1a will be described. In advance, the rotary grinding wheel 1a is attached to the tool spindle 27. The operator attaches the dresser 6 to the dressing spindle 43. The control device 12 rotates the dressing spindle 43 and the tool spindle 27. The control device 12 brings the rotary grinding wheel 1a into contact with the dresser 6 to perform truing or dressing.

[0049] Referring to FIG. 10, a method for measuring the tool diameter of the rotary grinding wheel 1a will be described. In advance, the rotary grinding wheel 1a is mounted on the tool spindle 27. The control device 12 rotates the tool spindle 27. The control device 12 moves the tool spindle 27 so that the optical axis 42 of the optical tool measuring instrument 41 is blocked by the rotary grinding wheel 1a. The control device 12 moves the rotary grinding wheel 1a in the direction perpendicular to the optical axis 42 (the X direction in FIG. 10) to obtain the coordinates of the tool spindle 27 when the rotary grinding wheel 1a no longer blocks the optical axis 42. The control device 12 calculates the distance from the optical axis 42 to the center of the spindle 27 to obtain the tool diameter of the rotary grinding wheel 1a.

[0050] According to the present embodiment, after the workpiece 3 is placed on the circular table 35, the eccentric position q3 of the workpiece center 3c is determined based on the positions of the first singular point 3a and the second singular point 3b of the workpiece 3. Then, based on the eccentric position q3, the outer circumference of the workpiece 3 can be cylindrical ground. Therefore, the workpiece 3 can be accurately ground regardless of the positioning accuracy of the installation of the workpiece 3.

[0051] According to the present embodiment, in order to determine the eccentric position q3 of the workpiece 3, when photographing the workpiece 3, a part of the workpiece 3 is placed in the measurement chamber 14. Then, the camera 31 installed in the measurement chamber 14 photographs the workpiece 3. After that, the entire workpiece 3 is placed in the processing chamber 13, and after the processing chamber 13 is blocked by the door 17, the workpiece 3 is ground. When the workpiece 3 is being ground and coolant and grinding chips scatter, the opening 16 is closed by the door 17. Therefore, the camera 31 and the lighting fixture 33 are prevented from being contaminated by the coolant and the grinding chips.

[0052] According to this embodiment, only a part of the workpiece 3 is placed inside the measurement chamber 14, and the workpiece 3 is rotated so that the camera 31 images the first singular point 3a and the second singular point 3b. Then, the eccentricity position q3 is determined from the obtained first singular point image 5a and second singular point image 5b. If the camera 31 images the first singular point 3a and the second singular point 3b without rotating the workpiece 3 by the circular table 35, it is necessary to accommodate the entire workpiece 3 inside the measurement chamber 14. In this embodiment, since it is not necessary to photograph both ends or the entire outer periphery of the workpiece, the measurement chamber 14 can be downsized. Then, the installation area of the grinding machine 10 can be reduced.

[0053] According to this embodiment, after grinding the outer periphery of the workpiece 3, the tool 1 attached to the spindle 27 can be appropriately replaced to perform grinding of the reference position of the workpiece 3, drilling of the workpiece 3, and grooving. During this time, the workpiece 3 is fixed to the circular table 35 by the chuck 37. Without removing or attaching the workpiece 3, a plurality of processing steps of the workpiece 3 can be completed. Since the grinding machine 10 can process the workpiece 3 based on the eccentricity position q3, the workpiece 3 can be processed with high precision. Also, compared to the case where the workpiece 3 is processed by a plurality of machines, the time for removing, attaching, and centering the workpiece 3 can be shortened.

[0054] <Embodiment 2> The workpiece 4 of this embodiment has a first singular point 4a, a second singular point 4b, and a workpiece center 4c. The first singular point 4a and the second singular point 4b are circular.

[0055] The grinding method of this embodiment will be described. The first singular point 4a of this embodiment does not have a reference line. Therefore, in step S3, the inclination of the reference line of the first singular point 4a is not adjusted. The method for determining the first singular point position q1 and the second singular point position q2 is substantially the same as that of the first embodiment.

[0056] A method for grinding the orientation flat 4d of the workpiece 4 will be described. FIG. 11 shows a situation where the first singular point position q1, the second singular point position q2, and the eccentric position q3 are determined at the C-axis coordinate C = c1 + 180 degrees. Here, the vector v1 (reference line) from the workpiece center 4c to the center 4b1 of the second singular point 4b is obtained by the following equation. TIFF2025092101000005.tif12136

[0057] Next, when the angle between the vector v1 and the Y-axis is c2 degrees, as shown in FIG. 12, the circular table 35 is positioned at the C-axis coordinate C3. Here, C3 = c1 - c2. Furthermore, the rotary grinding wheel 1a is applied to the workpiece 3 to grind it so as to create a plane separated by a distance 3e from the position of the workpiece center 3c at this time. The position of the workpiece center 3c is obtained by linearly transforming the eccentric position q3.

[0058] According to the present embodiment, even when the first singular point 4a and the second singular point 4b do not have a reference line, the phase of the workpiece 4 can be positioned parallel to the coordinate axes, and the orientation flat 4d can be machined.

[0059] The present invention is not limited to the above-described embodiments, and various modifications are possible without departing from the gist of the present invention. All technical matters included in the technical idea described in the claims are the subject of the present invention. The above embodiments show preferred examples, but those skilled in the art can realize various alternative examples, correction examples, modification examples, or improvement examples from the content disclosed in this specification, and these are included in the technical scope described in the appended claims.

Explanation of Reference Numerals

[0060] 1a Rotary grinding wheel 3, 4 Workpiece 3a, 4a First singular point 3b, 4b Second singular point 3c, 4c Workpiece center 5 Scanning angle 5a First singular point image 5b Second singular point image 10 Grinding machine 27 Tool spindle 31 Camera (imaging device) 35 Circular table 38 Table center q1 First singular point position q2 Second singular point position q3 Eccentric position u2 Position of the first singular point at the drawing angle u3 Position of the second singular point at the drawing angle

Claims

1. A disk-shaped workpiece having a workpiece center, a first singularity, and a second singularity is placed on a circular table that rotates about the table center, the circular table is rotated to place the first singularity within the imaging angle of the camera, and the camera acquires a first singularity image including the first singularity, the circular table is rotated by a predetermined angle, and the camera acquires a second singularity image including the second singularity, based on the position of the first singularity in the first singularity image, the position of the second singularity in the second singularity image, and the display magnification that is the ratio of the dimension in the real space to the display dimension of the imaging angle, an eccentricity position that is the coordinates of the workpiece center from the table center is determined, the circular table is rotated, and a tool spindle equipped with a rotary grinding wheel is moved to cylindrically grind the outer periphery of the workpiece about the workpiece center based on the eccentricity position and the rotation angle of the circular table, A cylindrical grinding method.

2. Furthermore, the circular table is moved to place a measurement reference arranged on the circular table within the imaging angle, and a reference image including the measurement reference is acquired, the circular table is moved in the front-rear direction or the left-right direction to align the orientation of the imaging angle in the front-rear direction or the left-right direction, The cylindrical grinding method according to Claim 1.

3. Furthermore, open a door that partitions the processing chamber and the measurement chamber, move the circular table, and move at least a part of the workpiece through the opened door into the measurement chamber, acquire the first singularity image and the second singularity image in the measurement chamber, move the circular table to move all of the workpiece into the processing chamber and then close the door, cylindrically grind the workpiece with the door closed, The cylindrical grinding method according to Claim 1 or 2.

4. Furthermore, process a workpiece reference on the workpiece based on the eccentricity position, The cylindrical grinding method according to Claim 1 or 2.

5. process a workpiece reference on the workpiece based on the angle between a reference straight line connecting the workpiece center and the first singularity or the second singularity and the eccentricity position, The cylindrical grinding method according to Claim 1 or 2.

6. A grinding machine for grinding a workpiece, a pedestal, a processing chamber, a measurement chamber having a camera for imaging the workpiece inside, a partition wall that partitions the processing chamber and the measurement chamber, an opening, a door for opening and closing the opening, a partition wall having the same, a pedestal having the same, A circular table on which the workpiece is placed and which is arranged on the gantry so as to be movable in the front-rear direction, wherein when the door is opened, at the moving end, the circular table is movable such that at least a part of the workpiece enters the measurement chamber through the opening. A tool spindle arranged in the machining chamber so as to be movable in the left-right and up-down directions. A grinding machine having the above.

7. The circular table has a table center, and the workpiece having a first singular point, a second singular point, and a workpiece center is placed thereon. A control device. A storage device. The first singular point image and the second singular point image captured by the imaging device. The position of the first singular point in the first singular point image. The position of the second singular point in the second singular point image. The eccentricity position which is the position of the workpiece center from the table center. The display magnification which is the ratio of the dimension in the real space to the display dimension of the angle of view. A storage device that stores the above. An arithmetic unit. An image processing function that extracts the shape of the first singular point from the first singular point image and calculates the position of the first singular point, and extracts the shape of the second singular point from the second singular point image and calculates the position of the second singular point. A center calculation function that calculates the eccentricity position of the workpiece center with respect to the table center based on the position of the first singular point, the position of the second singular point, and the display magnification. A numerical control function that rotates the circular table based on the eccentricity position and performs cylindrical grinding on the outer periphery of the workpiece with the workpiece center as the center based on the eccentricity position. An arithmetic unit having the above. Further having a control device having the above. The grinding machine according to claim 6.

8. Further having a table on which the circular table is placed and which is arranged on the gantry so as to be movable in the front-rear direction. The table is a measurement reference that enters the measurement chamber through the opening when the door is opened and is within the angle of view of the imaging device. The grinding machine according to claim 6 or 7.

9. Further having illumination arranged in the measurement chamber for illuminating the workpiece. The imaging device is arranged above the workpiece. The grinding machine according to claim 6 or 7.

10. Further having a tool changer that stores a plurality of tools including a cylindrical grinding tool and a touch probe and exchanges the tools attached to the tool spindle. The grinding machine according to claim 6 or 7.

11. The table is a dressing spindle that is rotatably arranged and has a dressing spindle to which a grinding wheel used for truing or dressing is attached. The grinding machine according to claim 8.

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