JP7328063B2 - Grinding equipment - Google Patents

Description

The present invention relates to grinding equipment.

As disclosed in Patent Document 1, a grinding apparatus for grinding a workpiece includes a holding surface height measuring gauge for measuring the height of a holding surface and a height of the upper surface of the workpiece held on the holding surface. and a top surface height measuring gauge for measuring, and determining the difference between the height of the holding surface measured by the holding surface height measuring gauge and the height of the top surface of the workpiece measured by the top surface height measuring gauge. , the thickness of the workpiece is calculated.

In calculating the amount of wear of the grinding wheel provided in the grinding device, the grinding wheel is pressed down against the workpiece held on the holding surface until the thickness calculated as described above reaches a preset thickness. At the same time, the height position of the grinding wheel when the grinding process is completed is stored in a storage device or the like provided in the grinding device. In addition, the height of the grinding wheel when the lower surface of the grinding wheel comes into contact with the holding surface is stored in advance as a reference height, and the thickness of the workpiece at the end of grinding is increased from the reference height. The difference between the height position corresponding to , and the position of the grinding wheel at the end of grinding is calculated as the amount of wear of the grinding wheel.

JP 2008-073785 A

However, when the thickness of the workpiece is large, there is a problem that the upper surface height measuring gauge cannot be raised to the upper surface of the workpiece and cannot measure the height of the workpiece. Moreover, there is a problem that the thickness of the workpiece cannot be measured normally because the holding surface becomes dirty.
Therefore, the grinding apparatus has the problem of measuring the thickness of the workpiece and recognizing the wear amount of the grinding wheel even if the thickness of the workpiece increases without being affected by the contamination of the holding surface.

The present invention comprises holding means for holding a workpiece on a holding surface, grinding means for grinding the upper surface of the workpiece held on the holding surface with a lower surface of a grinding wheel, and the grinding means on the holding surface. a grinding feed means for grinding and feeding in a direction perpendicular to the surface, a holding surface height measuring unit for measuring the height of the holding surface, and a top surface height for measuring the height of the upper surface of the workpiece held on the holding surface a measuring unit, comprising: measuring unit moving means for moving the top surface height measuring unit up and down in the grinding feeding direction; and a height position of the top surface height measuring unit moved up and down by the measuring unit moving unit. and a thickness calculator for calculating the thickness of the workpiece, and the upper surface height measuring unit includes a gauge having a contact at its tip that is brought into contact with the upper surface of the workpiece; a cylinder that houses a gauge so that it can protrude in the grinding feed direction; and a value of the scale when the height of the holding surface is measured by moving the upper surface height measuring unit up and down by the measuring unit moving means, and a value of the holding surface by the holding surface height measuring unit. The value recognized by the scale unit when it matches the measured value when measuring the height is taken as the origin of the top surface height measurement unit, and the thickness calculation unit calculates the scale of the top surface height measurement unit . The value of the relative height of the upper surface height measuring part from the origin is added to the value, and the value of the height of the holding surface measured by the holding surface height measuring part is subtracted from the workpiece It is a grinding device that calculates the thickness of
The above-described grinding apparatus includes a storage unit that stores the height of the lower surface of the grinding wheel that is in contact with the holding surface, and a value stored in the storage unit that is calculated by the thickness calculation unit at the end of grinding. It is desirable to include a wear amount calculation unit that calculates the wear amount of the grinding wheel by adding the thickness of the workpiece and subtracting the height position of the grinding wheel at the end of grinding.

By using the grinding apparatus according to the present invention, the origin position of the second reading section of the scale unit as the height position of the holding surface is recognized by the second reading section as the height position of the upper surface of the workpiece. By adding the height position and subtracting the height of the holding surface measured by the holding surface height measuring unit, the thickness of the workpiece can be calculated. This makes it possible to measure the thickness of a workpiece having a large thickness.
For example, it has become possible to measure the thickness of a workpiece having a thickness of 10 mm or more.
Further, the height of the lower surface of the grinding wheel when the lower surface of the grinding wheel is in contact with the holding surface and the height of the lower surface of the grinding wheel when the grinding is finished are stored in a storage unit provided in the grinding apparatus. , by adding the thickness of the workpiece to the height of the lower surface of the grinding wheel when the lower surface of the grinding wheel is in contact with the holding surface, and subtracting the height of the lower surface of the grinding wheel at the end of grinding. , it became possible to recognize the amount of wear of the grinding wheel.

It is a perspective view showing the whole grinding device. FIG. 3 is a cross-sectional view of the grinding apparatus viewed from the side in a state in which the contactor of the upper surface height measurement unit is in contact with the holding surface; FIG. 4 is a cross-sectional view of the grinding apparatus viewed from the side in a state where the contactor of the upper surface height measuring unit is in contact with the upper surface of the workpiece held on the holding surface;

1 Configuration of Grinding Apparatus A grinding apparatus 1 shown in FIG. The configuration of the grinding apparatus 1 will be described below.

The grinding device 1 includes a device base 10 extending in the Y-axis direction, and a column 11 erected on the +Y direction side of the device base 10 .

Grinding feed means 4 for supporting the grinding means 3 so as to move up and down is arranged on the side surface of the column 11 in the -Y direction. The grinding means 3 includes a spindle 30 having a rotating shaft 35 in the Z-axis direction, a housing 31 rotatably supporting the spindle 30, a spindle motor 32 rotating the spindle 30 about the rotating shaft 35, and the spindle 30. It has an annular mount 33 connected to the lower end thereof, and a grinding wheel 34 detachably attached to the lower surface of the mount 33 .
The grinding wheel 34 includes a wheel base 341 and a plurality of substantially rectangular parallelepiped grinding wheels 340 annularly arranged on the lower surface of the wheel base 341. The lower surface 340b of the grinding wheel 340 supports the workpiece W. It is a grinding surface to be ground.

The grinding feed means 4 includes a ball screw 40 having a rotating shaft 45 extending in the Z-axis direction, a pair of guide rails 41 arranged parallel to the ball screw 40, and a Z-rotor rotating the ball screw 40 around the rotating shaft 45. It comprises a shaft motor 42 , an elevating plate 43 having an internal nut screwed onto the ball screw 40 and having side portions in sliding contact with the guide rails 41 , and a holder 44 connected to the elevating plate 43 and supporting the grinding means 3 .

When the ball screw 40 is driven by the Z-axis motor 42 and rotates about the rotating shaft 45, the elevator plate 43 is guided by the guide rail 41 and moves up and down in the Z-axis direction. The grinding means 3 held by the holder 44 moves in the direction (Z-axis direction) perpendicular to the holding surface 20a.

The grinding device 1 includes a lower surface height recognition section 81 that recognizes the height of the lower surface 340 b of the grinding wheel 340 . The lower surface height recognizing unit 81 is adjacent to the first scale 810 disposed on the side surface of the guide rail 41 in the -Y direction, for example, and the side surface of the lift plate 43 in the +X direction, and the first scale 810. and a first reading unit 811 disposed at a position. The first reading unit 811 has, for example, an optical recognition mechanism or the like that reads the reflected light of the graduations formed on the first scale 810 , and can recognize the graduations of the first scale 810 . The first reading section 811 is electrically connected to a first storage section 84 having a storage element such as a memory.
When the elevating plate 43 moves up and down in the Z-axis direction when the grinding wheel 340 moves up and down in the Z-axis direction, the first reading unit 811 also moves up and down, and the height position of the first reading unit 811 changes. becomes.
The bottom surface height recognizing unit 81 can store the read scale value of the first scale 810 in the first storage unit 84 . The height position of the first reading portion 811 is associated with the height of the lower surface 340b of the grinding wheel 340, and based on the height position of the first reading portion 811, the height of the lower surface 340b of the grinding wheel 340 is determined. It is possible to measure and store the measured value in the first storage unit 84 .
In addition, the structure which does not have a scale as mentioned above may be sufficient. In that case, the Z-axis motor 42 is provided with an encoder, and the angle read by the encoder is converted into a distance in the Z-axis direction to recognize the height of the lower surface 340b.

A holding means 2 is arranged on the device base 10 . The holding means 2 includes, for example, a suction portion 20 having a porous member or the like and a frame body 21 that supports the suction portion 20 . The upper surface of the suction unit 20 is a holding surface 20a on which the workpiece W is held, and the upper surface 21a of the frame 21 and the holding surface 20a are flush with each other.

The holding means 2 is connected to, for example, a horizontal moving means 28 disposed inside the apparatus base 10, and can be driven by the horizontal moving means 28 to move in the Y-axis direction. The horizontal movement means 28 includes a ball screw 280 having a rotating shaft 285 in the Y-axis direction, a pair of guide rails 281 arranged parallel to the ball screw 280, and a Y-rotor rotating the ball screw 280 around the rotating shaft 285. A shaft motor 282 , a Y-axis base 283 having an internal nut screwed onto a ball screw 280 and having a bottom portion slidably contacting a guide rail 281 , and a chuck connected to the Y-axis base 283 via a support column 286 to support the holding means 2 . A table base 284 is provided. The chuck table base 284 rotatably supports the holding means 2 via bearings 5 .
When the ball screw 280 is driven by the Y-axis motor 282 and rotates about the rotating shaft 285, the Y-axis base 283 is guided by the guide rail 281 and moves in the Y-axis direction. The holding means 2 held by the chuck table base 284 is moved in the Y-axis direction.

A cover 12 and a bellows 13 telescopically connected to the cover 12 are arranged around the holding means 2 . When the holding means 2 moves in the Y-axis direction, the cover 12 moves in the Y-axis direction together with the base 22, and the bellows 13 expands and contracts.

A holding surface height measuring unit 60 is arranged on the device base 10 . The holding surface height measuring unit 60 includes a first cylinder 600 and a first gauge 601 housed in the first cylinder 600. At the tip of the first gauge 601, for example, the upper surface 21a of the frame 21, etc. A first contactor 601a is provided for contacting the . The first gauge 601 is supported so as to protrude in the -Z direction. The first cylinder 600 has a scale 600a, and a reading unit (not shown) provided in the first gauge 601 reads the value of the scale 600a, thereby recognizing the amount of protrusion of the first gauge 601 from the first cylinder 600. be.

A top surface height measuring unit 62 is arranged above the apparatus base 10, and a measurement is performed by moving the top surface height measuring unit 62 in the grinding feed direction (Z-axis direction) above the apparatus base 10. A part moving means 7 is provided. The measuring unit moving means 7 includes a back plate 74 erected in the Z-axis direction, a ball screw 70 disposed on the side surface of the back plate 74 on the +X direction side and having a rotating shaft 75 in the Z-axis direction. A pair of guide rails 71 arranged parallel to each other, a motor 72 that rotates the ball screw 70 around a rotary shaft 75, and a base 73 that slides on the guide rails 71 at its sides.

As shown in FIG. 1, the base 73 is provided with a top surface height measuring section 62 .
The upper surface height measuring unit 62 is connected and fixed to the second cylinder 620, the second gauge 621 connected to the lower end of the second cylinder 620, the upper part of the second cylinder 620, and the +X direction side surface of the base 73, respectively. and a second connecting member 622 that connects the two. A second contactor 621a that contacts the holding surface 20a of the holding means 2, the upper surface Wa of the workpiece W, and the like is provided at the lower end of the second gauge 621. As shown in FIG. The second gauge 621 is supported so as to protrude in the -Z direction. The second cylinder 620 is provided with a scale 620a, and a reading unit (not shown) provided in the second gauge 621 reads the value of the scale 620a, thereby recognizing the amount of protrusion of the second gauge 621 from the second cylinder 620. be.

At a position adjacent to the base 73, a scale unit 83 for recognizing the height position of the top surface height measuring section 62 is arranged. The scale unit 83 includes a second scale 830 extending parallel to the ball screw 70 and the guide rail 71 on the +X direction side of the back plate 74, and a -Y direction side of the base 73. and a second reading unit 831 .
The second reading unit 831 has, for example, an optical recognition mechanism that reads the reflected light of the graduations formed on the second scale 830 and can recognize the graduations of the second scale 830 . The second reading section 831 is electrically connected to a second storage section 85 having a storage element such as a memory. The second storage section 85 has a function of storing the positions of the graduations of the second scale 830 read by the second reading section 831 .
The scale unit 83 measures, for example, the height position of the second reading unit 831 when the second contact 621a of the upper surface height measuring unit 62 is in contact with the holding surface 20a as the origin, and the second storage unit 85 can be stored. Also, it is possible to measure the relative height position of the second reading unit 831 from the origin and store the measured value in the second storage unit 85 .

Further, as shown in FIG. 2, the measuring section moving means 7 is provided with a nut section 76 that is screwed onto the ball screw 70 and connected to the base 73 .
When the ball screw 70 is driven by the motor 72 and rotates about the rotary shaft 75, the base 73 is guided by the guide rails 71 and moves up and down in the Z-axis direction. The upper surface height measuring unit 62 provided moves up and down in the Z-axis direction integrally with the base 73 .

As shown in FIG. 2, rotating means 24 is provided below the holding means 2 . The rotating means 24 includes a drive shaft 241 rotatable around a rotation axis a in the Z-axis direction, a motor 242 for rotating the drive shaft 241, a drive pulley 240 connected to the upper end of the drive shaft 241, and a holding mechanism. A spindle 245 connected to the lower part of the means 2 and having a rotation axis 25 in the Z-axis direction, a driven pulley 244 connected to the spindle 245, a driving pulley 240 wound around the driven pulley 244, and driven by the driving force of the driving pulley 240. A transmission belt 243 for transmission to a pulley 244 and a rotary joint 246 connected to the lower end of a spindle 245 are provided.
When the drive shaft 241 is rotated using the motor 242 , the drive pulley 240 connected to the drive shaft 241 rotates, and the rotational force of the drive pulley 240 is transmitted to the driven pulley 244 by the transmission belt 243 . will rotate. When the driven pulley 244 rotates, the spindle 245 connected to the driven pulley 244 rotates about the rotation axis 25 in the Z-axis direction, and the holding means 2 connected to the spindle 245 rotates about the rotation axis 25. It is configured to rotate.

A suction source 260 , an air supply source 261 and a water supply source 262 are arranged below the holding means 2 . A suction source 260 , an air supply source 261 , and a water supply source 262 are each connected to the suction section 20 through the channel 27 . Between the suction part 20 and the suction source 260, between the suction part 20 and the air supply source 261, and between the suction part 20 and the water supply source 262 in the flow path 27, opening/closing valves 263a, 263b and 263c is provided.
When grinding the workpiece W or measuring the thickness of the workpiece W, the opening/closing valves 263a to 263c are appropriately controlled to open and close. For example, as shown in FIG. 3, in a state in which the workpiece W is placed on the holding surface 20a of the suction unit 20, the open/close valve 263a between the suction unit 20 and the suction source 260 is opened to 20 and a suction source 260 are communicated with each other, and the suction source 260 is operated to transmit the suction force exerted by the suction source 260 to the holding surface 20a. can hold.

The grinding machine 1 has a control means 8 for controlling various mechanisms provided in the grinding machine 1 .
The control means 8 includes a thickness calculator 80 for calculating the thickness of the workpiece W. As shown in FIG.
The control means 8 also includes a wear amount calculator 82 for calculating the wear amount of the grinding wheel 340 . The wear amount calculation unit 82 adds the height of the lower surface 340b of the grinding wheel 340 when the grinding wheel 340 is in contact with the holding surface 20a to the thickness of the workpiece W calculated by the thickness calculation unit 80 at the end of grinding. It has a function of calculating the wear amount of the grinding wheel 340 by adding the thickness and subtracting the height position of the lower surface 340b of the grinding wheel 340 at the end of grinding from the added value.

2 Grinding device operation (grinding and calculation of thickness)
By grinding the workpiece W using the grinding apparatus 1 while calculating the thickness of the workpiece W, the workpiece W is ground to a predetermined desired thickness.
When a plurality of workpieces W are continuously ground, the lower surface 340b of the grinding wheel 340 gradually wears away, and the grinding wheel 340 runs out, eventually making it impossible to grind. Therefore, in the grinding apparatus 1, the wear amount of the grinding wheel 340 is calculated after grinding the workpiece W, for example.
By calculating the amount of wear, it is possible to recognize the remaining amount of the grinding wheel 340 .

The operation of the grinding apparatus 1 when grinding the workpiece W while calculating the thickness of the workpiece W and the operation of the grinding apparatus 1 when calculating the wear amount of the grinding wheel 340 will be described below. do.

First, as shown in FIG. 2, the grinding means 3 is moved in the Z-axis direction using the grinding feed means 4 to bring the lower surface 340b of the grinding wheel 340 into contact with the holding surface 20a of the holding means 2. The first storage unit 84 stores the height of the lower surface 340b of the grinding wheel 340 when the lower surface 340b of the grinding wheel 340 contacts the holding surface 20a. The height of the lower surface 340b of the grinding wheel 340 when the lower surface 340b of the grinding wheel 340 contacts the holding surface 20a of the holding means 2 is stored in the first storage unit 84 and sent to the wear amount calculating unit 82 as an electrical signal. sent.

Also, the second contactor 621a of the upper surface height measuring part 62 is brought into contact with the holding surface 20a, and the amount of protrusion of the second gauge 621 from the second cylinder 620 is read from the scale 620a, and is used as the height of the holding surface 20a. measured. The measured height value of the holding surface 20a is transmitted to the thickness calculator 80 as an electrical signal.
Furthermore, the value of the scale of the second scale 830 of the scale unit 83 when the second contactor 621a is in contact with the holding surface 20a is read by the second reading section 831 and recognized. The height position recognized by the second reading unit 831 is stored in the second storage unit 85 as the height position of the origin.
Further, as shown in FIG. 3, the first contactor 601a of the holding surface height measuring unit 60 is brought into contact with the upper surface 21a of the frame 21 to measure the height of the holding surface 20a. The height of the holding surface 20a is measured by reading the amount of protrusion of the first gauge 601 from the first cylinder 600 from the scale 600a.
Since the first contactor 601a of the holding surface height measuring unit 60 and the second contactor 621a of the upper surface height measuring unit 62 measure the same surface, the value of the first contactor 601a and the value of the first contactor 601a The upper surface height measuring part 62 may be moved using the measuring part moving means 7 so that the value of the second contactor 621a becomes the same.
Note that the holding surface height measuring unit 60 may be of a direct-acting type in which the first contactor 601a is linearly moved in the Z-axis direction, or the first contactor 601a is disposed at the tip of an arm and the fulcrum is located at the center of the arm. A lever type may be used in which the first contactor 601a is moved in the Z-axis direction.

After that, the grinding wheel 340 is temporarily moved in the +Z direction by using the grinding feed means 4 to separate the grinding wheel 340 from the holding surface 20 a of the holding means 2 . Further, the upper surface height measuring part 62 is moved in the +Z direction by the measuring part moving means 7 to separate the second contactor 621a from the holding surface 20a of the holding means 2 .
Further, for example, the holding means 2 is moved in the Y-axis direction by the horizontal moving means 28 to separate the holding means 2 and the grinding means 3 in the horizontal direction.

Next, as shown in FIG. 3, the workpiece W is placed on the holding surface 20a of the holding means 2, and the suction source 61 is operated to exert a suction force. As a result, the generated suction force is transmitted to the holding surface 20a through the flow path 27, and the workpiece W is held by suction on the holding surface 20a.

The holding means 2 holding the workpiece W by suction is moved in the Y-axis direction using the horizontal movement means 28 to position the holding means 2 below the grinding means 3 .

As shown in FIG. 3, the first contactor 601a of the holding surface height measuring unit 60 is brought into contact with the upper surface 21a of the frame 21 to measure the height of the holding surface 20a. The height of the holding surface 20 a is measured by the amount of protrusion of the first gauge 601 from the first cylinder 600 .
Further, the base 73 is appropriately moved in the grinding feeding direction using the measuring part moving means 7, and the second contactor 621a of the second gauge 621 of the upper surface height measuring part 62 is brought into contact with the upper surface Wa of the workpiece W. . As a result, the height position of the scale of the second scale 830 when the second contactor 621a is in contact with the upper surface Wa of the workpiece W is read and recognized by the second reading section 831, and the second memory is read and recognized. The height of the upper surface Wa of the workpiece W is measured by the amount of protrusion of the second gauge 621 from the second cylinder 620 at that time, which is stored in the section 85 .
The measured height value of the holding surface 20a and the height of the second reading unit 831 when the second contactor 621a is in contact with the upper surface Wa of the workpiece W stored in the second storage unit 85 The position is transmitted to the thickness calculator 80 as an electrical signal.

After that, the motor 242 of the rotating means 24 is controlled to rotate the drive shaft 241 about the rotating shaft a. As a result, the drive pulley 240 connected to the drive shaft 241 rotates, and the rotational force thereof is transmitted to the driven pulley 244 by the transmission belt 243 to rotate the driven pulley 244 . As the driven pulley 244 rotates, the spindle 245 connected to the driven pulley 244 rotates around the rotating shaft 25 in the Z-axis direction. In this way, the holding means 2 connected to the spindle 245 and the workpiece W held on the holding surface 20a of the holding means 2 rotate about the rotating shaft 25. As shown in FIG.

Next, the spindle motor 32 of the grinding means 3 is used to rotate the spindle 30 around the rotating shaft 35 . As a result, the annular mount 33 connected to the lower end of the spindle 30 and the grinding wheel 340 connected to the mount 33 rotate about the rotation shaft 35 as well.

While the grinding wheel 340 is rotating, the ball screw 40 is driven by the Z-axis motor 42 of the grinding feed means 4 shown in FIG. As a result, the lifting plate 43 and the grinding wheel 340 supported by the lifting plate 43 via the holder 44 are lowered in the -Z direction, and as shown in FIG. It abuts on the workpiece W that is held by suction on 20a. The workpiece W is ground by further pushing down the grinding wheel 340 toward the workpiece W while the lower surface 340b is in contact with the workpiece W. As shown in FIG.

In the thickness calculator 80, before grinding, the value (A) of the height of the holding surface 20a measured by the upper surface height measuring unit 62 and read from the scale 600a and the height of the holding surface 20a by the upper surface height measuring unit 62 are calculated. The value (a) of the height position of the second reading unit 831 recognized by the scale unit 83 when the height is measured, and the value (a) of the height position of the second reading unit 831 when the workpiece W is held on the holding surface 20a and measured by the upper surface height measurement unit 62 The value (B) of the height of the upper surface Wa of the workpiece W read from the scale 620a and the scale unit 83 when the second contactor 621a of the upper surface measurement unit 62 is brought into contact with the upper surface Wa of the workpiece W. using the value (b) of the height position of the second reading unit 831 recognized in the second reading unit 831, the scale unit 83 The second reading recognized by the scale unit 83 when the height of the holding surface 20a is measured by the upper surface height measuring unit 62 before grinding from the value (b) of the height position of the second reading unit 831 recognized in The value (a) of the height position of the portion 831 is subtracted, and the upper surface Wa of the workpiece W measured by the upper surface height measuring unit 62 while the workpiece W is held on the holding surface 20a is calculated from the subtracted value. The thickness of the workpiece W is calculated by subtracting the value obtained by subtracting the value (A) of the height of the holding surface 20a measured by the upper surface height measurement unit 62 before grinding from the value (B) of the height. be done.
Note that the value (A) of the height of the holding surface 20a measured by the upper surface height measuring unit 62 measured before grinding and the height of the upper surface Wa of the workpiece W held on the holding surface 20a by the upper surface measuring unit 62 The measurement unit moving means 7 may be controlled so that the height value (B) becomes the same.
In this case, the height position value (b ) minus the value (a) of the height position of the second reading unit 831 recognized by the scale unit 83 when the height of the holding surface 20a is measured by the upper surface height measuring unit 62 before grinding. It is calculated as the thickness of the workpiece W.
Note that the height of the holding surface 20a is measured by the holding surface height measuring unit 60 because the height of the holding surface 20a changes due to the influence of processing heat during the grinding process.
The holding surface height before grinding is measured by the value of the scale 600a of the holding surface height measuring unit 60, the value (AA) of the height of the holding surface 20a before grinding is stored, and the holding surface height is measured during grinding. Subtracting the height value (AA) of the holding surface 20a before grinding from the value (AB) of the height of the holding surface 20a measured by the scale 600a of the height measuring unit 60, the change in the holding surface during grinding is calculated. recognize.
For example, if the holding surface 20a becomes 5 μm higher than before grinding due to processing heat during grinding, the holding surface height is measured by the holding surface height measuring unit 60, and the change in holding surface height is recognized as 5 μm.
At the same time, the upper surface height of the workpiece W is measured by the upper surface height measuring unit 62, whereby the thickness of the workpiece W is calculated as described above, and the value measured by the upper surface height measuring unit 62 is used. The thickness of the workpiece W actually held and ground by the holding surface 20a is calculated by subtracting the holding surface height (5 μm) changed by the heat of processing from the thickness of the workpiece W calculated by the above calculation.
Before grinding, the holding surface height was measured by the value of the scale 620a of the upper surface height measuring unit 62, and the holding surface height was measured by the value of the scale 600a of the holding surface height measuring unit 60. The value (A) of the height of the holding surface 20a measured by the measuring unit 62 and the value (AA) of the height of the holding surface 20a measured by the holding surface height measuring unit 60 may be matched.

When the workpiece W is ground and the height of the upper surface Wa of the workpiece W becomes lower, the second contactor 621a of the second gauge 621 of the upper surface height measuring unit 62 reaches the upper surface of the workpiece W. The height of the upper surface Wa of the workpiece W is measured by contacting Wa and using the value of the scale 620a. The amount of height that is reduced by grinding is 200 μm or less. The projection amount of the second contactor 621 of the second gauge 621 is 1 mm at maximum, and the amount of grinding of the upper surface Wa of the workpiece W can be measured up to 1 mm. Therefore, the second contactor 621a of the second gauge 621 of the upper surface height measuring unit 62 comes into contact with the upper surface Wa of the workpiece W, and the second gauge is positioned so that the height of the upper surface Wa of the workpiece W can be measured. 621 is moved in the Z-axis direction, and then the height of the upper surface Wa of the workpiece W, which is lowered by grinding, is measured by the amount of protrusion of the second contactor 621a.
During grinding, the thickness calculator 80 calculates the height of the holding surface 20a measured by the holding surface height measuring unit 60 and the workpiece held on the holding surface 20a measured by the upper surface height measuring unit 62. The thickness of the workpiece W is continuously calculated from the value of the upper surface height of the object and the height position of the scale of the second scale 830, and the thickness of the workpiece W is the preset desired thickness. The grinding process of the workpiece W is performed until it becomes The height of the holding surface 20a may fluctuate due to heat generated by grinding, etc., but by subtracting the value of the height of the holding surface 20a measured by the holding surface height measuring unit 60, such fluctuations can be taken into account. , the thickness of the workpiece W can be calculated.

As described above, the value of the thickness of the workpiece W at the end of grinding calculated by the thickness calculator 80 is transmitted to the wear amount calculator 82 as an electrical signal.

(Calculation of wear amount of grinding wheel)
When the workpiece W is ground and the thickness of the workpiece W reaches a preset desired thickness, the height of the lower surface 340b of the grinding wheel 340 at the end of grinding is stored in the first storage unit 84. do. The stored value of the height of the lower surface 340b of the grinding wheel 340 at the end of grinding is transmitted to the wear amount calculator 82 as an electrical signal.

Then, in the wear amount calculation unit 82, the height of the lower surface 340b of the grinding wheel 340 when the lower surface 340b of the grinding wheel 340 comes into contact with the holding surface 20a of the holding means 2 stored in advance before the grinding process is calculated by the thickness calculation unit The thickness of the workpiece W after grinding calculated in 80 is added, and the height position of the lower surface 340b of the grinding wheel 340 at the end of grinding is subtracted from the added value. Thereby, the wear amount of the grinding wheel 340 is calculated.

In the grinding apparatus 1, at the origin position of the second reading portion 831 of the scale unit 83 as the height position of the holding surface 20a, and at the second reading portion 831 as the height position of the upper surface Wa of the workpiece W The thickness of the workpiece W can be calculated by adding the recognized height positions and subtracting the height of the holding surface 20a measured by the holding surface height measuring unit 60. FIG. This makes it possible to measure the thickness of the workpiece W having a large thickness.
For example, it has become possible to measure the thickness of a workpiece W having a thickness of 10 mm or more.
Further, the height of the lower surface 340b of the grinding wheel 340 when the lower surface 340b of the grinding wheel 340 is in contact with the holding surface 20a is stored in the first storage unit 84 provided in the grinding apparatus 1, and the holding surface 20a is ground. Add the thickness of the workpiece to the value of the height of the lower surface 340b of the grinding wheel 340 when the lower surface 340b of the grinding wheel 340 is in contact, and subtract the height of the lower surface 340b of the grinding wheel 340 at the end of grinding. , the amount of wear of the grinding wheel 340 can be recognized. The remaining amount of the grinding wheel 340 can be recognized by summing up the wear amount of the grinding wheel 340 recognized when the grinding process is finished.

Reference Signs List 1: grinding device 10: device base 11: column 12: cover 13: bellows 2: holding means 20: suction part 20a: holding surface 21: frame 21a: upper surface of frame 24: rotating means 240: drive pulley 241: Drive shaft 242: Motor 243: Transmission belt 244: Driven pulley 245: Spindle 246: Rotary joint 25: Rotating shaft 260: Suction source 261: Air supply source 262: Water supply source 263a to 263c: Opening/closing valve 27: Suction path 28: Horizontal movement means 280: Ball screw 281: Guide rail 282: Y-axis motor 283: Y-axis base 284: Chuck table base 285: Rotating shaft 286: Support column 3: Grinding means 30: Spindle 31: Housing 32: Spindle motor 33: Mount 34: Grinding wheel 340: Grinding wheel 340b: Lower surface of grinding wheel 341: Wheel base 35: Rotating shaft 4: Grinding feeding means 40: Ball screw 41: Guide rail 42: Z-axis motor 43: Elevating plate 44: Holder 45: Rotation Axis 5: Bearing 60: Holding Surface Height Measuring Part 600: First Cylinder 601: First Gauge 601a: First Contactor 62: Upper Surface Height Measuring Part 620: Second Cylinder 621: Second Gauge 621a: Second Contact Child 7: Measuring part moving means 70: Ball screw 71: Guide rail 72: Motor 73: Base 74: Back plate 75: Rotating shaft 76: Nut part 8: Control means 80: Thickness calculator 81: Bottom surface height recognition part 810: First Scale 811: First Reading Section 82: Abrasion Amount Calculating Section 83: Scale Unit 830: Second Scale 831: Second Reading Section 84: First Storage Section 85: Second Storage Section W: Workpiece Wa: Workpiece top surface of workpiece

Claims (2)

holding means for holding the workpiece on the holding surface; grinding means for grinding the upper surface of the workpiece held on the holding surface with the lower surface of the grinding wheel; and the grinding means in a direction perpendicular to the holding surface. a holding surface height measuring unit for measuring the height of the holding surface; and a top surface height measuring unit for measuring the height of the top surface of the workpiece held on the holding surface. A grinding device comprising
moreover,
measuring unit moving means for moving the top surface height measuring unit up and down in the grinding feed direction;
a scale unit for recognizing the height position of the upper surface height measuring unit moved up and down by the measuring unit moving means;
A thickness calculation unit that calculates the thickness of the workpiece,
The top surface height measuring unit includes a gauge having a contact at its tip for contacting the top surface of the workpiece, a cylinder housing the gauge so as to protrude in the grinding feed direction, and a cylinder that moves up and down in the grinding feed direction. a scale for measuring the amount of protrusion of the gauge from the cylinder when the contact is in contact with the upper surface of the workpiece,
The value of the scale when the height of the holding surface is measured by moving the upper surface height measuring unit up and down by the measuring unit moving means, and the height of the holding surface is measured by the holding surface height measuring unit. The value recognized by the scale unit when it matches the measured value when the
The thickness calculator is
The height of the holding surface measured by the holding surface height measuring unit by adding the value of the relative height of the upper surface height measuring unit from the origin to the value of the scale of the upper surface height measuring unit A grinding device that calculates the thickness of a workpiece by subtracting the thickness value. a storage unit that stores the height of the lower surface of the grinding wheel that is in contact with the holding surface;
The thickness of the workpiece at the end of grinding calculated by the thickness calculating unit is added to the value stored in the storage unit, and the height position of the grinding wheel at the end of grinding is subtracted. 2. The grinding apparatus according to claim 1, further comprising a wear amount calculator for calculating the wear amount.

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