TWI761776B - Control device, program and grinding method of grinding device - Google Patents

Abstract

[Problem] To provide a control device of a polishing apparatus capable of suppressing heat accumulation in a workpiece and shortening the air cutting time. [Solution] The grinding device repeatedly performs for the workpiece: the feeding action of relatively moving the grinding wheel toward one of the directions in the surface of the workpiece, that is, the feeding direction, and the feeding of the grinding wheel toward the surface of the workpiece. The line feed direction of the direction crossing is a relatively moving line feed action to grind the workpiece. The control device of the grinding device executes the contact detection control. In the contact detection control, the feeding action and the cutting action of bringing the grinding wheel close to the workpiece are repeatedly performed, and the line feed action is not performed until the contact between the grinding wheel and the workpiece is detected. until. In addition, grinding control is performed in which grinding is performed by repeatedly performing a feeding operation and a line feed operation after detecting that the grinding wheel is in contact with the workpiece.

Description

Control device, program and grinding method of grinding device

The present invention relates to a control device of a polishing device, a program executed by the control device of the polishing device, and a polishing method. This application claims priority based on Japanese Patent Application No. 2019-054515 filed on March 22, 2019. The entire contents of the Japanese application are incorporated in this specification by reference.

As a method of grinding a workpiece having a width wider than the width of the grinding wheel while rotating the grinding wheel, an intermittent traverse grinding method and a displacement straight grinding method are known. In the intermittent traverse grinding method, the operation of moving the workpiece relative to the grinding wheel in a direction perpendicular to the width direction (feeding operation), and the traverse movement of the grinding wheel relative to the workpiece in the width direction by a length equal to or less than the width of the grinding wheel are repeated. action (line break action). After grinding the entire surface, an operation (cutting operation) of bringing the grinding wheel close to the workpiece is performed, and the grinding process of the second layer is performed (Patent Document 1). In the displacement straight grinding method, the feeding operation and the cutting operation are repeatedly performed until the grinding is performed to the target depth. After that, the line feed operation is performed, and the feeding operation and the cutting operation are repeatedly performed in the unprocessed area (Patent Document 2).

In any grinding method, it is necessary to perform the cutting action from the state where the grinding wheel has not yet contacted the workpiece to the state where it is in contact. When the grinding wheel is not in contact with the workpiece, the action of the feed action and the line feed action is called an air cut (AIR CUT, that is, an action without any grinding action). [Prior Art Literature]

[Patent Document 1] Japanese Patent Application Laid-Open No. 5-131363 [Patent Document 2] Japanese Patent Laid-Open No. 2002-307305

[Problems to be Solved by Invention]

In the intermittent traverse grinding method, during the air cutting period, the cutting operation is performed every time the feeding operation and the line changing operation are performed on the entire surface of the workpiece. Therefore, the air cut time will be longer. In the displacement straight grinding method, the feeding operation and the cutting operation are repeatedly performed during the air cutting period, so the air cutting time is shorter than the air cutting time of the intermittent traverse grinding method. However, in the displacement straight grinding method, the area to be ground in one feeding operation is continuously ground, so the heat generated by grinding is easily accumulated on the workpiece. As a result, the workpiece may be deformed by heat.

An object of the present invention is to provide a control device of a grinding device capable of suppressing heat accumulation in a workpiece and shortening the air cutting time. Another object of the present invention is to provide a program executed by the control device. Another object of the present invention is to provide a grinding method capable of suppressing heat accumulation in the workpiece and shortening the air cutting time. [Technical means to solve problems]

According to one aspect of the present invention, A control device for a grinding device is provided, which is used for contact detection control and grinding control for the grinding device, The grinding device repeatedly performs for the workpiece: a feeding action of relatively moving the grinding wheel toward one of the directions in the surface of the workpiece, that is, the feeding direction, and the combination of moving the grinding wheel toward the surface of the workpiece and the feeding direction. Make a relative movement of the line feed direction of the cross direction to carry out the grinding process on the aforementioned workpiece, In this contact detection control, the feeding operation and the cutting operation of bringing the grinding wheel close to the workpiece are repeatedly performed, and the line feed operation is not performed until it is detected that the grinding wheel is in contact with the workpiece. In this grinding control, after it is detected that the grinding wheel is in contact with the workpiece, the above-mentioned feed operation and the above-mentioned line feed operation are repeatedly performed to carry out the grinding process.

According to another aspect of the present invention, there is provided a program executed by the control device of the above-mentioned polishing apparatus.

According to another aspect of the present invention, The system provides a grinding method, which is performed repeatedly for the workpiece: the feeding action of making the grinding wheel move relatively in one of the directions in the surface of the workpiece, that is, the feeding direction, and the sum of the grinding wheel facing the surface of the workpiece. The line feed direction intersecting the feed direction performs a line feed action of relative movement to grind the workpiece, and The aforementioned feeding action and the cutting action of bringing the aforementioned grinding wheel close to the aforementioned workpiece are repeatedly performed, without performing the aforementioned switching action, until it is detected that the aforementioned grinding wheel is in contact with the aforementioned workpiece, After detecting that the grinding wheel is in contact with the workpiece, the above-mentioned feed operation and the above-mentioned line feed operation are repeatedly performed to perform grinding. [Effect of invention]

In the contact detection control, the line feed operation is not performed, so the time until the contact is detected (air cut time) can be shortened. In the grinding control, the line feed operation and the feeding operation are repeated, so that the heat generated by grinding can be prevented from accumulating in one location.

1-3, the control apparatus of the grinding|polishing apparatus based on an Example is demonstrated. FIG. 1 is a schematic diagram of a control device of a polishing apparatus according to an embodiment and a polishing apparatus controlled by the control device. The stage 11 and the column 15 are supported on the machine tool 10 so as to be slidable in directions orthogonal to each other. Define an xyz orthogonal coordinate system with the horizontal plane as the xy plane and the vertical direction as the z-axis direction.

The driving device 41 translates the stage 11 relative to the machine tool 10 toward the x-axis direction. The drive device 41 uses, for example, an electric motor, a hydraulic cylinder, or the like. The driving device 42 is used to translate the column 15 relative to the machine tool 10 toward the y-axis direction. The drive device 42 uses, for example, an electric motor.

A chuck 12 is mounted on the stage 11 . The workpiece 50 to be polished is fixed to the chuck 12 .

The column 15 supports the grinding wheel 17 above the stage 11 via the spindle head 16 . The drive device 43 mounted on the spindle head 16 rotates the grinding wheel 17 around a rotation axis parallel to the y-axis. The drive device 43 uses, for example, an electric motor. The drive device 44 mounted on the column 15 moves the spindle head 16 up and down in the z-axis direction relative to the column 15 .

The dressing device 18 for dressing the grinding wheel 17 is installed on the stage 11, for example. Furthermore, as shown by the dotted line in FIG. 1 , the dressing device 18 may be provided just above the grinding wheel 17 . By moving the column 15 and raising and lowering the spindle head 16 , the grinding wheel 17 can be moved to the processing position of the dressing device 18 . Dressing of the grinding wheel 17 can be performed by moving the grinding wheel 17 to the processing position of the dressing device 18 .

The control circuits 35 , 36 , 37 , and 38 control the driving devices 41 , 42 , 43 , and 44 according to the commands from the control device 30 , respectively. The control device 30 is constituted by, for example, a computer including a central processing unit (CPU) 31, a memory device 32, and the like. A program for controlling the operation of the polishing device is stored in the memory device 32 . When the CPU 31 executes this program, the workpiece 50 can be polished by the polishing apparatus.

Next, referring to FIG. 2 , the control performed by the control device 30 according to the embodiment will be described. FIG. 2 is a flowchart of the control of the polishing apparatus performed by the control apparatus 30 according to the embodiment. First, the control apparatus 30 performs the grinding|polishing of the 1st layer by controlling the height adjustment of the grindstone 17, the rotation of the grindstone 17, and the movement of the workpiece|work 50 (step S01). The operation of step S01 will be described in detail with reference to FIG. 3 .

FIG. 3 is a perspective view of the workpiece 50 and the grinding wheel 17 . The workpiece 50 has a rectangular (square or rectangular) shape in plan view. First, the grinding wheel 17 is raised and lowered to adjust the height of the grinding wheel 17 to such an extent that excessive cutting does not occur. Usually, in order to ensure sufficient safety, the height of the grinding wheel 17 is adjusted so that the lower end of the grinding wheel 17 is positioned slightly above the upper surface of the workpiece 50 .

The positional alignment of the workpiece 50 and the grinding wheel 17 is performed in the width direction (y-axis direction) of the workpiece 50 . For example, in the y-axis direction, the grinding wheel 17 is moved to a position where the edge in the width direction of the workpiece 50 falls within the width of the grinding wheel 17 and almost the entire area in the width direction of the grinding wheel 17 overlaps the workpiece 50 . In a state where the grinding wheel 17 is rotated, the workpiece 50 is translated in the x-axis direction (feeding direction). The action of moving the workpiece 50 in the feed direction is called a feed action. In the x-axis direction (length direction) of the workpiece 50, if the workpiece 50 moves to the position where the grinding wheel 17 is separated from the workpiece 50 (the position shown by the dotted line in FIG. 3), the grinding wheel 17 is directed to the y-axis direction (line feed direction). )move. The action of moving the grinding wheel 17 in the line feed direction is called a line feed action. The moving distance (line feed width) in the line feed direction in the line feed operation is set to be substantially equal to the width of the grinding wheel 17 .

Next, after the line feed operation is performed, the workpiece 50 is translated in a direction opposite to the moving direction of the workpiece 50 in the first feeding operation. After that, the grinding wheel 17 is moved by the same distance in the same direction as the moving direction of the grinding wheel 17 in the first line change operation. The entire surface of the workpiece 50 can be scanned with the grinding wheel 17 by repeating the feeding operation and the line feed operation. The scan performed by the grinding wheel 17 in the state that the grinding wheel 17 is not in contact with the workpiece 50 is called air cutting. The grinding system begins when the grinding wheel 17 comes into contact with the workpiece 50 . After the start of grinding, the line feed operation and the feed operation are repeated until the scanning of the entire area of the workpiece 50 is completed. Thereby, the polishing of the first layer is completed.

Next, as shown in FIG. 2, it is judged whether the dressing of the grinding wheel 17 is performed (step S02). For example, trimming is performed every time a predetermined area is ground. When the control device 30 determines that the dressing is to be performed, the control for performing the dressing of the grinding wheel 17 is executed (step S03). After finishing the dressing, the grinding wheel 17 is raised and lowered to a position slightly higher than the target height of the nearest grinding surface (step S04).

Due to factors such as wear of the grinding wheel 17 and the amount of mechanical loss of the grinding wheel 17 caused by the upward force applied to the grinding wheel 17, the surface height of the workpiece 50 obtained by grinding is not necessarily the same as the target surface. The height (target height) is the same. In step S04, considering the error between the target height of the surface of the workpiece 50 and the actual height after grinding, for example, the height of the grinding wheel 17 is set to be one layer higher than the target height of the final grinding surface of the workpiece 50. A position about 1 to 2 times the target cutting depth (the depth of the grinding amount) of the amount.

After that, the control device 30 performs one feeding operation while rotating the grinding wheel 17 (step S05). During this feeding operation, it is determined whether or not the grinding wheel 17 has come into contact with the workpiece 50 (step S06). For example, it can be determined whether or not the grinding wheel 17 has come into contact with the workpiece 50 by detecting the load of the driving device 43 . When the grinding wheel 17 is not in contact with the workpiece 50, the grinding wheel 17 is idling, so the load on the driving device 43 is only the friction of the rotating shaft, and the load is extremely small. When the grinding wheel 17 comes into contact with the workpiece 50, the load on the drive device 43 will increase rapidly. The magnitude of the load of the driving device 43 will be reflected in the magnitude of the driving current flowing through the electric motor of the driving device 43 , so whether the grinding wheel 17 has contacted the workpiece 50 can be determined according to the fluctuation of the driving current. Furthermore, in addition to this, it is also possible to determine whether or not the grinding wheel 17 has come into contact with the workpiece 50 by detecting the sound (acoustic emission) generated by the contact with an acoustic sensor.

When the grinding wheel 17 is not in contact with the workpiece 50, the cutting operation of the grinding wheel 17 is performed (step S07). Specifically, the grinding wheel 17 is lowered by a height corresponding to one cut. After the cutting operation is performed, the feeding operation of step S05 is performed. That is, the feed operation is performed to the same position in the width direction (y-axis direction) of the workpiece 50, and the line feed operation is not performed. In this way, the control device 30 does not perform the line feed operation, but performs the contact detection control for detecting whether or not the grinding wheel 17 and the workpiece 50 have come into contact (step S05 to step S07 ).

When it is detected in step S06 that the grinding wheel 17 and the workpiece 50 have come into contact with each other, the entire surface of the workpiece 50 is subjected to grinding control for repeating the feeding operation and the line feed operation (step S08). Specifically, every time a feed operation is performed, a line feed operation is performed. At this time, the line feed width at the time of line feed operation is almost equal to the width of the grinding wheel 17 . When it is determined in step S02 that dressing is not to be performed, the cutting operation for one layer of the grinding wheel 17 is performed (step S09 ), and thereafter, step S08 is performed.

After polishing one layer of the workpiece 50 in step S08, it is determined whether or not the polishing has been performed to the target depth (step S10). In the case where the grinding has not reached the target depth, it is determined in step S02 whether or not dressing is to be performed. After that, the procedures from step S03 to step S10 are executed again. When the target depth has been ground, the grinding process of the workpiece 50 is terminated.

Next, referring to FIG. 4A and FIG. 4B , the superior effect of the above-mentioned embodiment compared with the conventional intermittent traverse grinding method will be described.

FIG. 4A is a schematic diagram showing the movement locus of the grinding wheel 17 with respect to the workpiece 50 during the operation period from steps S04 to S08 ( FIG. 2 ) in the above-described embodiment. FIG. 4A shows an example in which the grinding wheel 17 comes into contact with the workpiece 50 after the cutting operation for three layers (step S07 ) is performed. In addition, an example is shown in which the line feed operation is performed three times and the feed operation is performed four times in order to grind the entire surface of the workpiece 50 .

The trajectory 21 in the x-axis direction in FIG. 4A represents the feeding operation in step S05. The track 22 in the z-axis direction from the end point of the track 21 to the start point of the track 21 directly below represents the cut-in operation of step S07. The first to third tracks 21 from the upper side correspond to tracks during the air cut period. The lowermost trajectory 21 corresponds to the feeding operation when the grinding wheel 17 is in contact with the workpiece 50 (step S05). The trajectory 23 in which the line feed operation and the feed operation are repeatedly performed represents the grinding operation in step S08.

As shown in FIG. 4A, the feeding operation and the cutting operation are repeatedly performed, and the line feed operation is not performed until the grinding wheel 17 comes into contact with the workpiece 50. Therefore, in the example shown in FIG. 4A, during the air cutting period, three Secondary feed action.

FIG. 4B is a schematic diagram showing the movement track of the grinding wheel 17 relative to the workpiece 50 in the conventional intermittent traverse grinding method. Conventionally, the line feed operation is also performed during the three-layer air cutting period until the grinding wheel 17 comes into contact with the workpiece 50 . The grinding wheel 17 comes into contact with the workpiece 50 in the feeding operation immediately following the cutting operation for three layers. Therefore, during the air cutting period, 12 feeding operations are performed.

Comparing FIGS. 4A and 4B , it can be seen that, in the case where the control device 30 ( FIG. 1 ) according to the embodiment is used for grinding, the feed operation during the air cutting period is compared with the conventional intermittent traverse grinding. less frequently. As a result, the idle cut time can be shortened.

Next, the effect of performing air cutting until the grinding wheel 17 comes into contact with the workpiece 50 after the dressing of the grinding wheel 17 (step S03 in FIG. 2 ) and before the grinding control (step S08 in FIG. 2 ) will be described.

If grinding with the grinding wheel 17 is continued, the wear of the grinding wheel 17 will increase, and the actual grinding depth will be shallower than the target grinding depth. In addition, the upward force applied to the grinding wheel 17 from the workpiece 50 will increase due to caving of the grinding wheel 17 or clogging of the sand holes. As a result, the amount of mechanical loss of the upward grinding wheel 17 increases. Due to the mechanical loss of the grinding wheel 17, the actual grinding depth is also shallower than the target grinding depth.

Therefore, the actual height of the surface of the workpiece 50 that is ground immediately before the dressing of the grinding wheel 17 is higher than the target height. Although the target height can be obtained from the cut-in amount of the grinding wheel 17, it is difficult to obtain the actual height. In order to absorb the difference between the target height and the actual height, after the grinding wheel 17 is dressed, the lower end of the grinding wheel 17 is set higher than the target height by a certain loss to perform air cutting. In the present embodiment, the time for air cutting which has to be performed after the dressing of the grinding wheel 17 can be shortened.

Next, referring to FIGS. 5A to 5E , the excellent effects of the above-mentioned embodiment compared with the conventional shifting and straight-forward polishing method will be described.

5A to 5E are cross-sectional views showing the positional relationship between the workpiece 50 and the grinding wheel 17 in the middle stage of grinding when the grinding wheel 17 is used to grind the workpiece 50 by the conventional displacement straight grinding method. FIG. 5A shows the positional relationship between the workpiece 50 and the grinding wheel 17 during the first-layer grinding in the first feeding operation. The cut-in depth from the surface of the workpiece 50 is represented by D1. In the line feed direction (y-axis direction) of the grinding wheel 17 , most of the grinding wheel 17 falls on the workpiece 50 , and only a very small part of the end portion does not fall on the workpiece 50 . The fact that a very small portion of the end of the grinding wheel 17 does not land on the workpiece 50 is due to the fact that the positions of the workpiece 50 and the grinding wheel 17 are aligned with the edges.

FIG. 5B shows the positional relationship between the workpiece 50 and the grinding wheel 17 when grinding the lowermost layer in the feeding operation for the same area as in FIG. 5A . The cutting depth D1 from the surface occurring in the most recent feeding action is equal to the cutting depth D1 in the feeding action of FIG. 5A . A level difference 51 is formed at the boundary between the polished region and the unpolished region of the workpiece 50 by a plurality of feeding operations for the same region. The area of the surface of the grinding wheel 17 in contact with the workpiece 50 is worn by grinding. Therefore, on the surface of the grinding wheel 17 , the level difference 19 is also formed at the boundary between the area that contacts the workpiece 50 and the area that does not fall on the workpiece 50 .

FIG. 5C shows the positional relationship between the workpiece 50 and the grinding wheel 17 at the time of the first-layer polishing after one line feed operation. The cut-in depth D1 is equal to the cut-in depth D1 in the feeding operation of FIG. 5A . The line feed width is almost equal to the width of the grinding wheel 17 (dimension in the y-axis direction). Therefore, the level difference 51 formed in the workpiece 50 and the level difference 19 formed in the grinding wheel 17 coincide with each other in the y-axis direction. The higher surface (the surface farther from the center of the grinding wheel 17 ) bounded by the step 19 is not in contact with the workpiece 50 . Therefore, the step 19 formed by the grinding wheel 17 gradually increases.

FIG. 5D shows the positional relationship between the workpiece 50 and the grinding wheel 17 when grinding the lowermost layer in the feeding operation for the same area as in FIG. 5C . The cutting depth D1 from the surface occurring in the most recent feeding action is equal to the cutting depth D1 in the feeding action of FIG. 5B . At this time, since the higher surface formed on the level difference 19 of the grinding wheel 17 is in contact with the surface of the workpiece 50, the contact area is ground.

FIG. 5E shows the surface shape of the workpiece 50 after the feeding operation shown in FIG. 5D. The surface 52A appearing in the multiple feeding actions of FIGS. 5A-5B and the surface 52B appearing in the multiple feeding actions of FIGS. 5C-5D become approximately the same height. However, the groove 53 appears at the position after being ground by the higher surface formed in the step 19 of the grinding wheel 17 as a boundary. The groove 53 needs to be removed by fine grinding again, so the time required for fine grinding will increase.

In contrast, in the present embodiment, the line feed operation is performed every time the feed operation is performed. Even if the level difference 19 is formed in the grinding wheel 17 in the first feeding operation, the height thereof will be lower than the level difference 19 formed by the plurality of feeding operations by the displacement straight grinding method. In addition, the higher surface, bounded by the step 19 formed in one feeding operation, is in contact with the surface of the workpiece 50 during the feeding operation after the line feed operation. Therefore, the level difference 19 does not increase cumulatively. Therefore, in this embodiment, the generation of the trench 53 shown in FIG. 5E can be suppressed.

In addition, in the conventional displacement straight grinding method, the feeding operation and the cutting operation are repeatedly performed for the same area of the workpiece 50, so the heat generated by grinding is accumulated, and the workpiece 50 is easily heated. On the other hand, in the present embodiment, before the grinding wheel 17 contacts the workpiece 50, the feeding operation and the cutting operation are repeatedly performed for the same area, and the line feed operation is not performed, but after the grinding wheel 17 contacts the workpiece 50, the The line feed operation and the feed operation are repeated. Therefore, it is possible to suppress heat accumulation in a specific area of the workpiece 50 and to suppress an excessive temperature rise of the workpiece 50 .

Next, the effect of not using the method of not performing the line feed operation during the air cutting period in the first layer polishing (step S01 in FIG. 2 ) will be described.

The workpiece 50 is sometimes deformed due to the influence of the previous process, resulting in poor surface flatness. It is not easy to find the highest part of the surface of the workpiece 50 . If the grinding wheel 17 is lowered until the grinding wheel 17 comes into contact with the workpiece 50 by repeating the feeding operation and the cutting operation at only one location in the y-axis direction (width direction) of FIG. 3 , the cutting depth may be higher than the detection depth. The surface of the contact part becomes too large. In the present embodiment, air cutting is performed on the entire area of the workpiece 50 before the first-layer grinding, so that it is possible to suppress the problem that the cutting depth becomes too large in the area where the surface height is the highest.

Next, a modification of the above-described embodiment will be described. In the above-described embodiment, when the first layer polishing (step S01 in FIG. 2 ) is performed, the entire area of the workpiece 50 is air-cut. As mentioned above, this is because the surface height of the workpiece 50 is not uniform and it is not known which part is the highest. When the surface of the workpiece 50 before grinding is substantially flat, the air cutting (contact detection control) without performing the line feed operation in steps S05 to S07 may be performed during the first-layer grinding.

In addition, in the above-described embodiment, after the entire area of the workpiece 50 is ground for one layer in step S08, it is determined in step S02 whether the grinding wheel 17 is to be dressed. Whether or not dressing of the grinding wheel 17 is to be performed is determined at a time point in the middle of the surface. In this case, after the dressing of the grinding wheel 17 is performed, the routine of step S04 may be started from the part where the grinding was interrupted.

In addition, in the above-mentioned embodiment, although the line feed width of the line feed operation during grinding in step S08 is set substantially equal to the width of the grinding wheel 17 , it may be set smaller than the width of the grinding wheel 17 . For example, the line feed width may be set to about 50% of the width of the grinding wheel 17 .

In addition, according to the control device 30 of the above-described embodiment, although the control of the polishing device for polishing a flat plate is performed, the control of the polishing device for polishing the side surface of a cylindrical workpiece can also be performed. At this time, the feeding action corresponds to the action of rotating the workpiece around the center axis, and the feeding direction corresponds to the circumferential direction of the side surface of the workpiece. The line feed direction corresponds to the direction of the central axis of the workpiece.

In addition, in the above-mentioned embodiment, although the line feed operation is performed every time the feed operation is performed, it is also possible to set the depth of cutting into the workpiece 50 to be shallower according to the material of the workpiece 50 or the cutting conditions. , and the line feed operation is performed every time multiple (2 or 3) feeding operations are performed. According to this method, processing can be performed with high precision according to the material of the workpiece 50 or the like.

Next, another modification of the above-mentioned embodiment will be described with reference to FIG. 6 . FIG. 6 is a plan view of a workpiece 50 as a polishing target of the polishing apparatus equipped with the control device according to the present modification. In the present modification, the surface of the workpiece 50 is divided into a plurality of regions 55 . The control device 30 executes the program of the flowchart shown in FIG. 2 according to the area 55 .

When the size of the workpiece 50 in the line feed direction is large, even if air cutting is performed on the entire area of the workpiece 50 in step S01 , it may not be possible to cut once due to the limitation of the durability of the grinding wheel 17 . Just grind the entire area. At this point, air-cutting of unpolished areas becomes unnecessary. By dividing the surface of the workpiece 50 into a plurality of regions 55, unnecessary empty cuts can be eliminated.

The above-mentioned embodiments and modified examples are merely examples, and it is of course possible to partially replace or combine the constituent contents disclosed in the embodiments and modified examples. It is not necessary to mention the same functions and effects based on the same constituent content of the embodiment and the modification one by one for each embodiment and modification. In addition, the present invention is not limited to the above-described embodiments and modifications. For example, a person skilled in the art should be able to perform various changes, improvements, combinations, and the like.

10: Machine tools 11: Carrier 12: Chuck 15: Column 16: Spindle head 17: Grinding wheel 18: Dressing device 19: Stage difference 21, 22, 23, 25: Trajectories 30: Control device 31: Central Processing Unit (CPU) 32: Memory Device 35, 36, 37, 38: Control Circuits 41, 42, 43, 44: Drives 50: Workpiece 51: Stage difference 52A, 52B: Surfaces developed by grinding 53: Groove 55: The area obtained by dividing the surface of the workpiece

Fig. 1 is a schematic diagram of a control device of a polishing apparatus according to an embodiment and a polishing apparatus controlled by the control apparatus. FIG. 2 is a flowchart of the control of the polishing apparatus performed by the control apparatus of the embodiment. [FIG. 3] It is a perspective view of a workpiece and a grinding wheel. Fig. 4A is a schematic diagram showing the movement locus of the grinding wheel relative to the workpiece during the operation period from step S04 to step S08 ( Fig. 2 ) of the embodiment, FIG. 4B is a schematic diagram showing the movement trajectory of the grinding wheel with respect to the workpiece in the conventional intermittent traverse grinding method. 5A to 5E are cross-sectional views showing the positional relationship between the workpiece and the grinding wheel in the middle stage of grinding when the workpiece is ground with the grinding wheel by the conventional displacement straight grinding method. 6 is a plan view of a workpiece to be polished as a polishing device mounted with a control device according to a modification of the embodiment.

Claims (5)

A control device of a grinding device is used to perform contact detection control and grinding control for the grinding device, and the grinding device repeatedly performs on the workpiece: making the grinding wheel move relative to one of the directions in the surface of the workpiece, that is, the feeding direction. The feed action and the feed action for moving the grinding wheel toward the surface of the workpiece relative to the feed direction intersecting the feed direction are used to grind the workpiece. In the contact detection control, the The above-mentioned feeding operation and the cutting operation of bringing the grinding wheel close to the workpiece by a height equivalent to one cutting amount are repeatedly performed without performing the above-mentioned line-feeding operation until it is detected that the grinding wheel is in contact with the workpiece. In the control, after detecting that the grinding wheel is in contact with the workpiece, the above-mentioned feeding operation and the above-mentioned line feed operation are repeatedly performed to carry out the grinding process. The control device for a polishing apparatus according to claim 1, wherein the contact detection control is performed after the control for dressing the grinding wheel is performed and before the polishing control is performed. The control device for a polishing apparatus according to claim 1 or claim 2, wherein the surface of the workpiece is divided into a plurality of regions, and the contact detection control and the polishing control are performed for each region. A control program of a polishing device is executed by a control device of the polishing device that performs contact detection control and polishing control for the polishing device, The grinding device repeatedly performs for the workpiece: a feeding action of relatively moving the grinding wheel toward one of the directions in the surface of the workpiece, that is, the feeding direction, and the combination of moving the grinding wheel toward the surface of the workpiece and the feeding direction. In this contact detection control, the above-mentioned feeding operation and the cutting operation of bringing the above-mentioned grinding wheel close to the above-mentioned workpiece are repeatedly performed, and the The line feed operation is not performed until the contact between the grinding wheel and the workpiece is detected. In this grinding control, after the contact between the grinding wheel and the workpiece is detected, the feed operation and the line feed operation are repeatedly performed to perform grinding. processing. A grinding method is repeatedly performed for the workpiece: the feeding action of making the grinding wheel move relative to one of the directions in the surface of the workpiece, that is, the feeding direction, and the difference between the grinding wheel facing the surface of the workpiece and the feeding direction. The line feed action of relatively moving the line feed direction of the intersecting direction is used to grind the aforementioned workpiece, and the aforementioned feed action and the cutting action of making the aforementioned grinding wheel close to the aforementioned workpiece are repeatedly performed without performing the aforementioned line feed action until detection. It is known that the grinding process is performed by repeating the above-mentioned feeding operation and the above-mentioned line feed operation after detecting that the grinding wheel and the above-mentioned workpiece are in contact until the above-mentioned grinding wheel is in contact with the above-mentioned workpiece.

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