JP2021070126A - Creep feed grinding method and grinding device - Google Patents

Abstract

To grind a work-piece into an even thickness without being accompanied by complicated height-position control of grinding means.SOLUTION: A work-piece W is ground into an even thickness by executing a creep feed grinding method which comprises: a trial-grinding step of trial-grinding the work-piece W using a grinding stone 340; a thickness measuring step of measuring a thickness T1 at one end side and a thickness T2 at the other end side respectively of the work-piece W subjected to trial-grinding, using the thickness measuring means 7; a thickness difference calculating step of calculating a thickness difference D by subtracting the T1 from the T2 using the thickness difference calculating means 8; a holding surface inclining step of inclining a holding surface 20a by moving down one end 211 of a frame body 21 of a chuck table 2 in a -Z direction using an inclination adjustment mechanism 6, on the basis of the calculated thickness difference D; and a grinding step of grinding a new work-piece W using the grinding stone after inclining the holding surface 20a.SELECTED DRAWING: Figure 6

Description

The present invention relates to a creep feed grinding method and a grinding device.

By positioning the lower surface of the grinding wheel at a height below the upper surface of the workpiece held on the holding surface of the chuck table and moving the grinding wheel and the chuck table in the relatively horizontal Y-axis direction, the surface is covered. In creep feed grinding, in which a grinding wheel is moved from one end side to the other end side of the upper surface of the work piece to grind the work piece, the thickness of the work piece on one end side and the work piece on the other end side are processed due to the consumption of the grinding wheel. There is a difference in thickness with the thickness of the object.

Therefore, as disclosed in Patent Document 1, the amount of wear of the grinding wheel in relation to the position in the Y-axis direction is grasped, and the grinding wheel is worn while moving the workpiece with respect to the grinding wheel in the Y-axis direction. The grinding wheel is lowered by the amount to reduce the difference in thickness generated in the workpiece.

Japanese Unexamined Patent Publication No. 2016-002598

However, in the above grinding, the grinding wheel is lowered according to the position in the Y-axis direction while the workpiece and the grinding wheel are relatively moved in the Y-axis direction. There is a problem that control is difficult because a control unit for controlling the relative movement of the Y-axis and the Z-axis in the directions of the two axes is required.

In the present invention, the workpiece held on the holding surface and the rotating grinding wheel are relatively moved in the Y-axis direction parallel to the holding surface, and the workpiece is moved from one end side to the other end side. A creep-feed grinding method in which the upper surface of a work piece is ground using the grinding wheel, and the lower surface of the grinding wheel is positioned below the upper surface of the work piece held by the holding surface by a predetermined distance and processed. The trial grinding step of grinding the upper surface of the workpiece by relatively moving the object and the grinding wheel in the Y-axis direction, and the workpiece held on the holding surface ground in the trial grinding step are described. A thickness measuring step of moving in the Y-axis direction and measuring the thickness of the workpiece at least one end and the other end in the Y-axis direction using a thickness measuring means, and one end side of the workpiece measured in the thickness measuring step. The thickness difference calculation step of calculating the thickness difference between the thickness of the work piece and the thickness of the other end side of the work piece, and the one end side where the work piece thickness measured in the thickness measurement step is small is kept away from the lower surface of the grinding wheel. A holding surface tilting step of tilting the holding surface by moving the thickness difference downward and a predetermined distance below the upper surface of one end side of the workpiece newly held by the holding surface tilted in the holding surface tilting step. This is a creep feed grinding method comprising a grinding step of positioning the lower surface of the grinding wheel and grinding the upper surface of the workpiece by relatively moving the workpiece and the grinding wheel in the Y-axis direction.
In the trial grinding step, it is desirable to grind the workpiece held on the holding surface a plurality of times.
The present invention comprises a chuck table that holds a work piece on a holding surface, and a grinding means that grinds the work piece by rotating the grinding wheel around the center of a grinding wheel in which a grinding wheel is arranged in an annular shape on a base. A horizontal moving means for moving the chuck table and the grinding means relatively in the Y-axis direction parallel to the holding surface, and a vertical moving means for moving the grinding means in the Z-axis direction perpendicular to the holding surface. A grinding device that creep-feed grinds the upper surface of the workpiece from one end side to the other end side of the workpiece using the grinding wheel, and the workpiece held on the holding surface. A thickness measuring means for measuring the thickness, a thickness difference calculating means for calculating the thickness difference between the thickness on one end side and the thickness on the other end side of the workpiece measured by the thickness measuring means, and the Y-axis direction. The tilt adjusting mechanism for adjusting the tilt of the holding surface and the downward direction of the one end side or the other end side where the thickness of the workpiece measured by the thickness measuring means is smaller than the lower surface of the grinding wheel. It is a grinding device provided with a control means for controlling the tilt adjusting mechanism and tilting the holding surface so as to move the thickness difference.

In the present invention, since the inclination of the holding surface is adjusted before grinding, a complicated operation such as lowering the grinding wheel during the grinding process as in the conventional case becomes unnecessary.
Further, when the workpiece is finished to a desired thickness by creep feed grinding a plurality of times, the difference in thickness between one end and the other end is calculated after performing trial grinding for the number of times of the creep feed grinding. , One end of the holding surface is lowered by the amount corresponding to the difference. After that, by performing creep feed grinding of the workpiece, it is possible to finish it to a desired thickness in consideration of the consumption of the grinding wheel.

It is a perspective view which shows the whole grinding apparatus. (A) is a cross-sectional view of the work piece before trial grinding, and (b) is a cross-sectional view of the work piece during trial grinding. ) Is a cross-sectional view of the work piece at the end of trial grinding as seen from the side. (A) is a cross-sectional view showing how the height of the holding surface is measured by using the holding surface height measuring means, and (b) is a cross-sectional view showing how the height of the holding surface is measured by using the holding surface height measuring means. It is sectional drawing which shows the state of measuring the height, (c) is the sectional view which shows the state of measuring the height of the other end side of the upper surface of the work piece. It is sectional drawing which shows the state of tilting a holding surface. (A) is a cross-sectional view showing a state during grinding of the work piece, and (b) is a cross-sectional view showing a state after grinding of the work piece. (A) is a cross-sectional view showing the state after the first trial grinding, and (b) shows a state in which one end side of the chuck table is raised by using an inclination adjusting mechanism to make the upper surface of the work piece horizontal. It is a cross-sectional view. (A) is a cross-sectional view showing the state after the first grinding, and (b) shows the other end side of the chuck table using the tilt adjusting mechanism after rotating the chuck table 180 degrees by using the rotating means. It is sectional drawing which shows the state that the upper surface of the workpiece is made horizontal by lowering.

1 Grinding device The grinding device 1 shown in FIG. 1 is a grinding device that grinds the workpiece W held on the holding surface 20a. Hereinafter, the grinding device 1 will be described.
As shown in FIG. 1, the grinding device 1 includes a base 10 and a column 11 erected on the −X direction side of the base 10.

A chuck table 2 is arranged on the base 10. The chuck table 2 includes, for example, a rectangular suction portion 20 and a frame body 21 that supports the suction portion 20. The upper surface of the suction portion 20 is a holding surface 20a on which the workpiece W is held, and the holding surface 20a is formed flush with the upper surface 21a of the frame body 21.
Further, the frame body 21 of the chuck table 2 is supported by the rotating means 24. The rotating means 24 has a function of rotating the chuck table 2 about a rotating shaft 25 parallel to the Z axis.

On the + X direction side of the column 11, a vertical moving means 4 for moving the grinding means 3 in the Z-axis direction perpendicular to the holding surface 20a is arranged.
The grinding means 3 includes a spindle 30 having a rotating shaft 35 in the Z-axis direction, a housing 31 that rotatably supports the spindle 30, a spindle motor 32 that rotationally drives the spindle 30 around the rotating shaft 35, and a spindle 30. An annular mount 33 connected to the lower end of the mount 33 and a grinding wheel 34 detachably attached to the lower surface of the mount 33 are provided.
The grinding wheel 34 includes a wheel base 341 and a plurality of substantially rectangular grinding wheels 340 arranged in an annular shape on the lower surface of the wheel base 341, and the lower surface 340a of the grinding wheel 340 has a workpiece W. It is a grinding surface to be ground.

By rotating the spindle 30 around the rotating shaft 35 using the spindle motor 32, the mount 33 connected to the spindle 30 and the grinding wheel 34 mounted on the mount 33 are integrally centered on the rotating shaft 35. Will rotate.

The vertical moving means 4 has a ball screw 40 having a rotating shaft 45 in the Z-axis direction, a pair of guide rails 41 arranged parallel to the ball screw 40, and a Z that rotates the ball screw 40 around the rotating shaft 45. It includes a shaft motor 42, an elevating plate 43 in which an internal nut is screwed into a ball screw 40 and a side portion is in sliding contact with a guide rail 41, and a holder 44 which is connected to the elevating plate 43 and supports the grinding means 3.

When the ball screw 40 is driven by the Z-axis motor 42 and the ball screw 40 rotates about the rotation shaft 45, the elevating plate 43 is guided by the guide rail 41 and moves up and down in the Z-axis direction. The grinding means 3 held in the holder 44 moves in the Z-axis direction.

An internal base 12 is arranged inside the base 10. A horizontal moving means 5 for horizontally moving the chuck table 2 in the Y-axis direction is arranged on the internal base 12.
The horizontal moving means 5 includes a ball screw 50 having a rotation axis 55 in the Y-axis direction, a Y-axis motor 52 that rotates the ball screw 50 around the rotation axis 55, and a pair of balls arranged in parallel with the ball screw 50. It includes a guide rail 51 and a movable plate 53 whose inner nut is screwed into a ball screw 50 and whose bottom is in sliding contact with the guide rail 51.

By driving the ball screw 50 using the Y-axis motor 52, when the ball screw 50 rotates about the rotation shaft 55, the movable plate 53 moves horizontally in the Y-axis direction while being guided by the guide rail 51.

An inclination adjusting mechanism 6 is arranged on the movable plate 53. The tilt adjusting mechanism 6 includes a support plate 62 that supports the rotating means 24, a support roller 60 that extends in the X-axis direction arranged on the + Y direction side of the bottom surface of the support plate 62, and-of the bottom surface of the support plate 62. It is provided with an elevating shaft 61 arranged on the Y direction side.
By moving the elevating shaft 61 up and down in the Z-axis direction and adjusting the inclination of the support plate 62 with the support roller 60 as a fulcrum, the holding surface 20a of the chuck table 2 supported by the support plate 62 via the rotating means 24 The inclination in the Y-axis direction can be adjusted.
The elevating shaft 61 may be, for example, a laminated piezoelectric element that expands and contracts according to an applied voltage.
Further, the support roller 60 may be changed to a support column.

A cover 28 is arranged around the chuck table 2, and a bellows 29 is stretchably connected to the cover 28. For example, when the chuck table 2 is moved in the Y-axis direction by the horizontal moving means 5, the cover 28 moves in the Y-axis direction together with the chuck table 2 and the bellows 29 expands and contracts.

The thickness measuring means 7 is arranged on the −X direction side of the moving path of the chuck table 2 on the base 10. The thickness measuring means 7 includes a top surface height measuring means 71, a holding surface height measuring means 72, and a calculation unit 73.
The upper surface height measuring means 71 includes a first contactor 710 that comes into contact with the upper surface Wa of the workpiece W, and a first scale 711 that recognizes the height position of the first contactor 710. The holding surface height measuring means 72 includes a second contact 720 that contacts the upper surface 21a of the frame body 21 and a second scale 721 that recognizes the height position of the second contact 720.
The height of the upper surface Wa of the workpiece W is increased by bringing the first contact 710 of the upper surface height measuring means 71 into contact with the upper surface Wa of the workpiece W while the workpiece W is held on the holding surface 20a. Can be measured. Further, by bringing the second contact 720 of the holding surface height measuring means 72 into contact with the upper surface 21a of the frame body 21, the height of the holding surface 20a flush with the upper surface 21a of the frame body 21 can be measured. ..
In the calculation unit 73, the height of the holding surface 20a is subtracted from the measured height of the upper surface Wa of the workpiece W, and the thickness of the workpiece W is measured.

The grinding device 1 includes a thickness difference calculating means 8. The thickness difference calculating means 8 can calculate the difference D between the thickness on one end side and the thickness on the other end side of the workpiece W.

The grinding device 1 includes a control means 9 for controlling the operation of various mechanisms provided in the grinding device 1. The control means 9 is a tilt adjusting mechanism 6 that moves the side where the thickness of the workpiece W measured by the thickness measuring means 7 is small away from the lower surface 340a of the grinding wheel 340 in the downward direction calculated by the thickness difference calculating means 8. Has a function of tilting the holding surface 20a by controlling the above.

2 Grinding method (1) First embodiment (trial grinding process)
A method of grinding the workpiece W using the above-mentioned grinding device 1 will be described. First, as shown in FIG. 2A, the workpiece W is placed on the holding surface 20a of the chuck table 2 and a suction source or the like (not shown) is operated to transmit the suction force to the holding surface 20a. As a result, the workpiece W is sucked and held on the holding surface 20a.

Next, the spindle 30 of the grinding means 3 is rotated around the rotating shaft 35. As a result, the grinding wheel 340 rotates around the rotating shaft 35.
In a state where the grinding wheel 340 is rotating about the rotating shaft 35, the grinding means 3 is lowered in the −Z direction by using the vertical moving means 4, and the workpiece W held on the holding surface 20a is The lower surface 340a of the grinding wheel 340 is positioned below the height position of the upper surface Wa by a predetermined distance.
Then, the chuck table 2 is moved in the −Y direction by using the horizontal moving means 5.

As a result, as shown in FIG. 2B, the workpiece W and the grinding wheel 340 come into contact with each other. At this time, the −Y direction side of the grinding wheel 340 is positioned at a lower height than the + Y direction side, and the −Y direction side of the grinding wheel 340 comes into contact with the workpiece W.
As shown in FIG. 2C, the chuck table 2 is further moved in the −Y direction in a state where the workpiece W and the grinding wheel 340 are in contact with each other. As a result, the upper surface Wa side of the workpiece W is creep-fed grounded by the grinding wheel 340.

Since the grinding wheel 340 is consumed by grinding the work piece W, the thickness of the work piece W after grinding is not uniform as shown in FIG. 2C, and the work piece W is in the −Y direction. The thickness on the side is smaller than the thickness on the + Y direction side.

(Thickness calculation process)
Next, the grinding means 3 is moved in the + Z direction by using the vertical moving means 4, and the grinding wheel 340 is separated from the workpiece W.
Then, as shown in FIG. 3A, the second contact 720 of the holding surface height measuring means 72 is brought into contact with the other end 212 of the frame 21 of the chuck table 2 to read the value of the second scale 721. The height of the other end 212 of the frame 21 is measured. Further, the chuck table 2 is moved in the + Y direction, the second contactor 720 is brought into contact with one end 211 of the frame body 21 as shown by the alternate long and short dash line in FIG. 3A, and the value of the second scale 721 is read. The height of one end 211 of the frame 21 is measured.

Further, as shown in FIG. 3B, the first contact 710 is brought into contact with the other end E2 of the upper surface Wa of the workpiece W to read the value of the first scale 711, and the upper surface Wa of the workpiece W is read. Measure the height of the other end E2. Then, the height T2 on the other end side of the work piece W is measured by subtracting the height of the other end 212 of the frame body 21 from the height of the other end E2 of the upper surface Wa of the work piece W.

Further, as shown in FIG. 3C, after the chuck table 2 is moved in the + Y direction by using the horizontal moving means 5, the first contact 710 of the upper surface height measuring means 71 is moved to the upper surface of the workpiece W. One end of Wa is brought into contact with E1 to read the value of the first scale 711, and the height of one end E1 of the workpiece W is measured. Then, the height T1 on one end side of the work piece W is measured by subtracting the height of one end 211 of the frame body 21 from the height of one end E1 of the upper surface Wa of the work piece W.

For example, while measuring the height of the upper surface Wa of the workpiece W using the upper surface height measuring means 71, the height of the upper surface 21a of the frame body 21 is measured using the holding surface height measuring means 72. May be good.

(Thickness difference calculation process)
The values of the thickness T1 on one end side of the workpiece W and the thickness T2 on the other end side of the workpiece W measured by the thickness measuring means 7 as described above are shown in FIG. It is sent to the thickness difference calculating means 8 shown. Then, in the thickness difference calculating means 8, the thickness T1 on one end side of the workpiece W and the thickness T2 on the other end side of the workpiece W are subtracted, and the thickness T1 on one end side of the workpiece W and others are subtracted. The thickness difference D from the thickness T2 on the end side is calculated.

(Holding surface tilting process)
Next, the one end E1 side where the thickness of the work piece W that has been trial-ground is small is moved downward (-Z direction) by the amount of the thickness difference D calculated by the thickness difference calculating means 8 from the lower surface 340a of the grinding wheel 340. And tilt the holding surface 20a.
Specifically, the tilt adjusting mechanism 6 is controlled by the control means 9 shown in FIG. 4, and the elevating shaft 61 is lowered by the amount of the thickness difference D in the −Z direction. When one end 211 of the frame body 21 of the chuck table 2 is lowered in the −Z direction by the amount of the thickness difference D, the −Y direction side of the holding surface 20a of the chuck table 2 is tilted downward with the support roller 60 as the axis. Then, one end E1 of the upper surface Wa of the workpiece W held by the chuck table 2 is lowered by the amount of the thickness difference D in the −Z direction.

(Grinding process)
After tilting the holding surface 20a as described above, the workpiece W is ground. First, as shown in FIG. 4, a new workpiece W is held on the holding surface 20a, and then the grinding wheel 340 is lowered in the −Z direction using the vertical moving means 4, and one end of the workpiece W is The lower surface 340a of the grinding wheel 340 is positioned below the upper surface Wa on the E1 side by a predetermined distance. Next, by using the horizontal moving means 5 to move the chuck table 2 in the −Y direction as shown in FIG. 5A, the grinding wheel 340 comes into contact with the workpiece W and creeps the workpiece W. Feed grinding is started. Then, as shown in FIG. 5B, when the workpiece W moves in the −Y direction side with respect to the grinding wheel 340, the upper surface Wa side of the workpiece W is creep-fed ground. Since the holding surface 20a of the chuck table 2 is tilted in advance according to the wear of the grinding wheel 340 by creep feed grinding, the surface to be ground Wb formed by grinding becomes a surface parallel to the upper surface Wa before grinding and is covered. The thickness of the work piece W becomes uniform. By tilting the holding surface 20a before grinding, it is not necessary to perform difficult control of changing the height position of the grinding wheel 340 in the Z-axis direction during grinding.

In the grinding process, the load on the grinding wheel 340 in the horizontal direction is larger than that in the trial grinding. Therefore, in consideration of the larger wear of the grinding wheel 340, the holding surface 20a is slightly larger than the thickness difference D. It may be moved downward (-Z direction).

(2) Second Embodiment In the first embodiment, the case where the creep feed grinding is performed only once for one workpiece is described, but the creep feed grinding may be performed a plurality of times for one workpiece. In that case, since the grinding wheel 340 is worn even in the second and subsequent creep feed grindings, the plurality of times of grinding is performed also in the trial grinding process. For example, when creep feed grinding is performed twice, the following method is used.

As shown in FIG. 6A, the grinding wheel 340 is brought into contact with the upper surface Wa side of the workpiece W in a state where the holding surface 20a is horizontal with respect to the Y-axis direction, as in FIG. 2, and the chuck table 2 Is moved in the −Y direction to perform the first trial grinding. The thickness of the workpiece W after grinding is not uniform, and the thickness of the workpiece W on the −Y direction side is smaller than the thickness on the + Y direction side (first trial grinding step).

Next, the thickness calculation step and the thickness difference calculation step are carried out in the same manner as in the first embodiment, and the thickness difference D1 between the thickness on one end side and the thickness on the other end side of the workpiece W is calculated. Then, the holding surface tilting step is performed, and as shown in FIG. 6B, the holding surface 20a is tilted by moving one end E1 side having a small thickness closer to the lower surface 340a of the grinding wheel 340 by the thickness difference D1 in the + Z direction. .. As a result, the surface Wb to be ground of the workpiece W after trial grinding becomes horizontal with respect to the Y-axis direction.

In this way, the second trial grinding step is performed with the surface Wb to be ground horizontal with respect to the Y-axis direction. Then, the thickness calculation step and the thickness difference calculation step are carried out in the same manner as after the first trial grinding step, and the thickness on one end side and the thickness on the other end side of the workpiece W after the second trial grinding step are obtained. The thickness difference D2 (not shown) is calculated.

When the thickness differences D1 and D2 are calculated in this way, creep feed grinding is performed twice in the grinding process. In the first creep feed grinding, the holding surface 20a is tilted by moving one end E1 side away from the lower surface 340a of the grinding wheel 340 by the thickness difference D1 from the horizontal state, and the holding surface 20a is tilted in that state. Grind. Next, in the second creep feed grinding, the holding surface 20a is tilted by moving one end E1 side further away from the lower surface 340a of the grinding wheel 340 by the thickness difference D2 in the −Z direction, and creep feed grinding is performed in that state.

In this way, when the creep feed grinding is performed a plurality of times, the trial grinding step, the thickness calculation step, the thickness difference calculation step, and the holding surface tilting step are also performed a plurality of times to perform the creep feed grinding a plurality of times. The thickness of the work piece can be made uniform.

As shown in FIG. 7A, in a configuration in which the chuck table 2 can rotate about the rotating shaft 25 with respect to the movable plate 53, the following method can be adopted.

That is, first, as in FIG. 6A, the chuck table 2 is moved in the −Y direction while the grinding wheel 340 is in contact with the upper surface Wa side of the workpiece W to perform the first trial grinding. I do. The thickness of the workpiece W after grinding is not uniform, and the thickness of the workpiece W on the −Y direction side is smaller than the thickness on the + Y direction side (first trial grinding step). Then, the thickness calculation step and the thickness difference calculation step are carried out to calculate the thickness difference D1 between the thickness on one end side and the thickness on the other end side of the workpiece W.

Next, the chuck table 2 is rotated 180 degrees around the rotation shaft 25. Then, the direction of the workpiece W in the Y-axis direction is reversed, and the thicker one is on the −Y direction side and the thinner one is on the + Y direction side. Then, by moving the grinding wheel 340 away from the lower surface 340a by the thickness difference D1 in the −Z direction and tilting the holding surface 20a, the surface Wb to be ground becomes the Y-axis direction as shown in FIG. 7B. It becomes horizontal.

In this way, the direction of the workpiece W in the Y-axis direction is reversed, the surface Wb to be ground is made horizontal with respect to the Y-axis direction, and then the second trial grinding step is performed. In this step, grinding is performed from the thicker side to the smaller side, so that the work piece after the completion of this step is in a state where the thickness is close to uniform. Then, the thickness calculation step and the thickness difference calculation step are carried out in the same manner as after the first trial grinding step, and the thickness on one end side and the thickness on the other end side of the workpiece W after the second trial grinding step are obtained. The thickness difference D2 (not shown) is calculated.

When the thickness differences D1 and D2 are calculated in this way, creep feed grinding is performed twice in the grinding process. In the first creep feed grinding, the holding surface 20a is tilted by moving one end E1 side away from the lower surface 340a of the grinding wheel 340 by the thickness difference D1 from the horizontal state, and the holding surface 20a is tilted in that state. Grind. Next, in the second creep feed grinding, after rotating the chuck table 2 180 degrees around the rotation shaft 25, one end E1 side is further moved away from the lower surface 340a of the grinding wheel 340 by the thickness difference D2 in the −Z direction. The holding surface 20a is tilted, and creep feed grinding is performed in that state.

In this way, the chuck table 2 may be rotated 180 degrees between the thickness difference calculation step and the holding surface tilting step. Even by such a method, the thickness of the workpiece after the plurality of creep feed grinding can be made uniform.

Further, even when the creep feed grinding is performed only once, the trial grinding process may be performed a plurality of times. In this case as well, as in the second embodiment, after the completion of one trial grinding process, the surface to be ground is made horizontal with respect to the Y-axis direction, and the next trial grinding process is performed in that state to perform trial grinding. The work piece can be used many times. Further, by changing the difference in height position in the Z-axis direction between the upper surface of the workpiece before trial grinding and the lower surface of the grinding wheel, that is, the removal amount of the workpiece in trial grinding for each number of times, each removal amount And the corresponding thickness difference between one end and the other end of the work piece can be grasped.

1: Grinding device 10: Base 11: Column 12: Internal base 2: Chuck table 20: Suction part 20a: Holding surface 21: Frame body 21a: Top surface of frame body 211: One end of frame body 212: One end of frame body 24: Rotating means 25: Rotating shaft 28: Cover 29: Bellows cover 3: Grinding means 30: Spindle 31: Housing 32: Spindle motor 33: Mount 34: Grinding wheel 340: Grinding grind 340a: Bottom surface of grinding grind 341: Wheel base 35 : Rotating shaft 4: Vertical moving means 40: Ball screw 41: Guide rail 42: Z-axis motor 43: Elevating plate 44: Holder 45: Rotating shaft 5: Horizontal moving means 50: Ball screw 51: Guide rail 52: Y-axis motor 53: Movable plate 55: Rotating shaft 6: Tilt adjusting mechanism 60: Support roller 61: Elevating shaft 62: Support plate 7: Thickness measuring means 71: Top surface height measuring means 710: First contact 711: First scale 72: Holding surface Height measuring means 720: Second contact 721: Second scale 73: Calculation unit 8: Thickness difference calculating means 9: Control means W: Work piece Wa: Top surface of work piece Wb: Grinding formed by grinding Surface E1: One end of the work piece E2: The other end of the work piece T1: Thickness on one end side T2: Thickness on the other end side D1, D2: Difference in thickness

Claims (3)

The workpiece held on the holding surface and the rotating grinding wheel are relatively moved in the Y-axis direction parallel to the holding surface, and the workpiece is moved from one end side to the other end side of the workpiece. A creep feed grinding method in which the upper surface is ground using the grinding wheel.
The lower surface of the grinding wheel is positioned below the upper surface of the workpiece held on the holding surface by a predetermined distance, and the workpiece and the grinding wheel are relatively moved in the Y-axis direction to move the upper surface of the workpiece relatively. Trial grinding process and
The workpiece held on the holding surface ground in the trial grinding step is moved in the Y-axis direction, and the thickness of the workpiece at least one end and the other end in the Y-axis direction is measured by using a thickness measuring means. The thickness measurement process to be measured and
A thickness difference calculation step for calculating the thickness difference between the thickness on one end side of the work piece and the thickness on the other end side of the work piece measured in the thickness measurement step.
A holding surface tilting step of tilting the holding surface by moving the one end side having a small thickness of the workpiece measured in the thickness measuring step downward by a difference in thickness away from the lower surface of the grinding wheel.
The lower surface of the grinding wheel is positioned below the upper surface of one end side of the workpiece newly held by the holding surface tilted in the holding surface tilting step by a predetermined distance, and the workpiece and the grinding wheel are relative to each other. A grinding process that grinds the upper surface of the work piece by moving it in the Y-axis direction.
Creep feed grinding method consisting of. The creep feed grinding method according to claim 1, wherein the trial grinding step performs grinding on the workpiece held on the holding surface a plurality of times. A chuck table that holds the workpiece on the holding surface, a grinding means that rotates the grinding wheel around the center of the grinding wheel that is annularly arranged on the base of the grinding wheel to grind the workpiece, and the chuck table. A horizontal moving means for moving the grinding means and the grinding means relatively in the Y-axis direction parallel to the holding surface, and a vertical moving means for moving the grinding means in the Z-axis direction perpendicular to the holding surface. A grinding device that creep-feed grinds the upper surface of a work piece from one end side to the other end side of the work piece using the grinding wheel.
A thickness measuring means for measuring the thickness of the workpiece held on the holding surface, and
A thickness difference calculating means for calculating the thickness difference between the thickness on one end side and the thickness on the other end side of the workpiece measured by the thickness measuring means, and
An inclination adjusting mechanism for adjusting the inclination of the holding surface in the Y-axis direction,
The inclination adjusting mechanism is controlled so that the one end side or the other end side, which is measured by the thickness measuring means and has a small thickness, is moved downward by the thickness difference away from the lower surface of the grinding wheel. A grinding device including a control means for tilting the holding surface.

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