JP2013226625A - Grinding method and grinding device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To control a grinding feed means so that a grinding wheel does not lose its spontaneous edge-sharpening action in case a plate-like workpiece formed of hard-to-be-ground material is subjected to grinding.SOLUTION: A grinding method including use of a grinding device 1 includes: a first grinding feed step, in which, when a loading value of a grinding wheel 15 acting on a plate-like workpiece W has reached a predetermined threshold value, a control section 7 brings a grinding feed means 20 to raise a grinding means 10 at a prescribed grinding feed velocity; and a second grinding feed step in which, when, due to the raise, the loading value of the grinding wheel 15 acting on the plate-like workpiece W is found to have no load, the control section 7 brings the grinding feed means 20 to lower the grinding means 10 at a predetermined grinding feed velocity. The first grinding feed step and the second grinding feed step are alternately repeatedly performed. Consequently, even if the plate-like workpiece W formed of a hard-to-be-ground material is put to grinding, the grinding wheel 15 is free from losing its spontaneous edge-sharpening action, with the resultant continuation of grinding being performed on the plate-like workpiece W.

Description

  The present invention relates to a grinding method for grinding a workpiece formed of a difficult-to-grind material and a grinding apparatus capable of performing the grinding method.

  In a grinding apparatus for grinding a plate-like workpiece, the plate-like workpiece is held on a holding table, and a grinding wheel is brought into contact with the plate-like workpiece to grind the plate-like workpiece to a predetermined thickness. During the grinding of the plate-like workpiece, the holding table rotates and the grinding means provided with the grinding wheel rotates and feeds in a direction toward the holding table at a predetermined speed.

  When the plate-like workpiece, which is the workpiece, is formed of a difficult-to-grind material (for example, sapphire, silicon carbide, etc.), the grinding means is ground and fed at a predetermined grinding feed speed to grind the plate-like workpiece However, the plate-shaped workpiece is not reduced to a desired thickness, and the grinding wheel presses the plate-shaped workpiece, and an excessive rotational load is applied to the motor that rotates the grinding wheel. In response to such a problem, the following Patent Document 1 proposes a polishing apparatus that detects a pressure generated during processing of a workpiece as a rotational load applied to a motor and controls a processing feed rate. Patent Document 2 below proposes a machining apparatus that detects a pressure difference of air in a radial direction or a thrust direction of a spindle and controls a machining feed rate.

JP 2001-138219 A JP 2008-49445 A

  However, in the control for detecting the pressure applied to the grinding wheel as a rotational load applied to the motor as described above, the rotation of the motor that rotates the grinding wheel after the grinding wheel is pressed against the plate-like work and the load is applied to the plate-like work. Since it is detected as a load, there is a time lag between when a load is applied and when a rotational load is detected. Therefore, even after the load is applied, the grinding means is further fed by grinding and the grinding wheel is pressed against the plate-like workpiece, and the grinding wheel is crushed. As a result, the self-sharpening action of the grinding wheel may be lost and the plate workpiece may not be ground.

  The present invention has been made in view of the above circumstances, and when grinding a plate-like workpiece formed of a difficult-to-grind material with a grinding wheel, grinding feed is performed so that the grinding wheel does not lose its self-generated blade action. Control has problems to be solved by the invention.

  The first invention is a holding table for holding a plate-like workpiece, a grinding means for grinding a plate-like workpiece by bringing a grinding wheel into contact with the plate-like workpiece held on the holding table, and a direction approaching and holding the holding table The present invention relates to a grinding method using a grinding apparatus including a grinding feed means for grinding and feeding a grinding means in a direction away from a table. The holding table or the grinding means includes a plate-like workpiece when the grinding means is ground and fed by the grinding feed means. Load detecting means for detecting the grinding load is disposed, the grinding feed means lowers the grinding means to bring the grinding wheel into contact with the plate-like workpiece held on the holding table, and the grinding means is moved at a predetermined grinding feed speed. When the load value detected by the load detecting means reaches a predetermined threshold value by lowering, the grinding means is raised at a predetermined speed by the grinding feed means. When the load value detected by the load detecting means becomes no load by raising the grinding means in the first grinding feed process and the first grinding feed process, the grinding means is used to perform predetermined grinding. A second grinding feed step for lowering the feed rate, and the first grinding feed step and the second grinding feed step are alternately repeated.

  According to a second aspect of the present invention, there is provided a holding table for holding a plate-like work, a grinding means for grinding the plate-like work held by the holding table, and a grinding means in a direction approaching the holding table and a direction away from the holding table. A load detecting means for detecting a grinding load applied to a plate-like workpiece when the grinding means is ground and fed by the grinding feed means; When the load value detected by the detecting means reaches a predetermined threshold value, the grinding means is raised at a predetermined speed by the grinding feed means, and the load value detected by the load detecting means by the rising of the grinding means is no load. Control when the grinding means is lowered at a predetermined speed by the grinding feed means and the grinding means is lifted and lowered alternately by the grinding feed means. Provided with a door.

  A first invention is a grinding method using a grinding apparatus comprising a holding table, a grinding means for grinding a plate-like workpiece, and a grinding feed means for grinding and feeding the grinding means, and the holding table or the grinding means includes: A load detecting means for detecting a grinding load applied to the plate-like workpiece when the plate-like workpiece is ground by the grinding wheel mounted on the grinding means is provided, and the grinding means is lowered at a predetermined grinding feed speed. A first grinding feed step of raising the grinding means at a predetermined speed by the grinding feed means when the load value detected by the load detection means reaches a predetermined threshold, and the grinding in the first grinding feed step A second grinding feeder that lowers the grinding means at a predetermined grinding feed speed by the grinding feed means when the load value detected by the load detection means is unloaded by raising the means Therefore, the grinding feed of the grinding means by the grinding feed means can be controlled according to the grinding load applied to the plate-like workpiece, and there is no time lag until the grinding means rises after the load is applied. The grinding wheel is not clogged and the self-generated blade action of the grinding wheel is not lost. Further, since the plate-like workpiece is ground by alternately repeating the first grinding feed step and the second grinding feed step, grinding can be performed while ensuring the self-generated blade action of the grinding wheel. Even if it is a plate-like workpiece formed of a difficult-to-grind material, grinding can be continued.

  According to a second aspect of the present invention, there is provided a load detecting means for detecting a grinding load applied to the plate-like workpiece when the grinding means is fed by the grinding feed means, and the load value detected by the load detecting means has reached a predetermined threshold value. Sometimes, the grinding means is raised at a predetermined speed by the grinding feed means, and when the load value detected by the load detection means becomes no load due to the rising of the grinding means, the grinding means is moved at the predetermined speed by the grinding feed means. And a control unit that performs control to alternately and repeatedly raise and lower the grinding means by the grinding feed means. When the load value detected by the load detection means reaches a predetermined threshold value, the grinding means is predetermined. When the load value detected by the load detection means becomes no load due to this increase, the grinding means can be lowered, and such control can be repeated. Therefore, for the plate-shaped workpiece formed by the flame grinding material, it is possible to perform grinding continued while securing the self-sharpening action of the grinding wheel.

It is sectional drawing which shows the structure of a grinding device. It is a flowchart which shows the procedure of the grinding method. It is a graph which shows the relationship between the height position of the grinding means by grinding feed, and a grinding load value.

  A grinding apparatus 1 shown in FIG. 1 is a grinding apparatus that performs grinding on a plate-like workpiece W formed of various materials. The grinding apparatus 1 includes a base 100 extending in the Y-axis direction and a standing base 101 extending from the end of the base 100 in the Z-axis direction. The grinding apparatus 1 includes a holding table 2 for holding the plate-like workpiece W, a grinding means 10 for grinding the plate-like workpiece W held on the holding table 2, a direction approaching the holding table 2, and the holding table 2 And a grinding feed means 20 that feeds the grinding means 10 in a direction away from the grinding means 10.

  A rotatable turntable 3 is disposed on the upper surface of the base 100. A rotation shaft 4 having an axis in the Z-axis direction is disposed at the center portion of the turntable 3. The holding table 2 includes a table base 2a and a holding portion 2b disposed on the upper surface side of the table base 2a. The surface of the holding portion 2b is a holding surface 2c that holds the plate-like workpiece W by suction. The holding table 2 is supported on the turntable 3 by connecting one end of the support portion 2d to the turntable 3 and connecting the other end to the lower end of the table base 2a. And when the turntable 3 rotates, the holding table 2 can be revolved.

  A rotary shaft 8 having a suction path communicating with the suction source 9 is connected to the lower end of the center of the table base 2a. A belt 30 is wound around the rotating shaft 8, and this belt 30 is also wound around the rotating shaft of the motor 31. By driving the motor 31, the chuck table 2 can be rotated in the direction of arrow A, for example. it can.

  As shown in FIG. 1, the grinding means 10 is disposed on the side of the standing base 101 via the grinding feed means 20. The grinding means 10 includes a spindle 11 having an axis C in the Z-axis direction, a spindle housing 12 that rotatably supports the spindle 11, a grinding wheel 14 that is mounted on the lower end of the spindle 11 via a mounter 13, A plurality of grinding wheels 15 fixed in an annular shape to the lower part of the wheel 14 and a motor (not shown) connected to the spindle 11 inside the spindle housing 12 are provided. And in the grinding means 10, the grinding wheel 14 can be rotated with a motor.

  A grinding feed means 20 that moves the grinding means 10 up and down is disposed on the side of the grinding means 10. The grinding feed means 20 includes a rotatable ball screw 21 extending in the Z-axis direction, a motor 22 connected to the upper end of the ball screw 21, a shaft support 23 that rotatably supports the ball screw 21, and the spindle housing 12 side. And a moving base 24 that moves up and down the grinding means 10. The grinding feed means 20 can move the moving base 24 in the Z-axis direction by rotating the ball screw 21 by driving the motor 22, and can also move the grinding means 10 in the Z-axis direction.

  As shown in FIG. 1, a load detecting means 5 for detecting a grinding load applied to the plate-like workpiece W when the plate-like workpiece W held on the holding table 2 is ground is attached to the upper end side of the support portion 2d. It has been. The load detecting means 5 is in contact with the lower end of the table base 2b so that the holding table 2 can be rotated. The load detection means 5 includes a piezoelectric element used for piezoelectric load measurement. When the piezoelectric element receives pressure applied to the plate-like workpiece W by the grinding wheel 15, it can generate a voltage. The load detection means 5 can detect this voltage as a load value applied to the plate-like workpiece W. For example, the load detecting means 5 can be attached to three positions at the lower end of the holding table 2. Further, the load detecting means 5 may be arranged inside the grinding means 10, for example, between the spindle housing 12 supporting the spindle 11 and the spindle 11 in the vertical direction.

  A determination unit 6 is connected to the load detection unit 5 to determine whether or not the load value detected by the load detection unit 5 has reached a threshold value preset in the grinding device 1. Furthermore, based on the determination result of the determination unit 6, a control unit 7 that controls the grinding unit 10 to repeat the lifting and lowering operation of the grinding unit 10 alternately is connected to the determination unit 6 and the grinding feed unit 20.

  Below, the procedure which grinds the plate-shaped workpiece | work W using the grinding apparatus 1 comprised as mentioned above is demonstrated along the flowchart shown in FIG. The plate-like workpiece W to be ground is made of a difficult-to-grind material such as sapphire or silicon carbide.

  In the grinding apparatus 1 shown in FIG. 1, the threshold value of the grinding load applied to the plate-like workpiece W by the grinding means 10 and detected by the load detection means 5 is set in the determination unit 6 in advance as 100 N, for example. Then, when the load value of the grinding wheel 15 applied to the plate-like workpiece W reaches a threshold value, the control unit 7 is previously set so that the grinding feed means 20 raises the grinding means 10 at a grinding feed speed of 0.5 mm / s. Set it. Further, when the load value of the grinding wheel 15 applied to the plate-like workpiece W becomes no load (0 N), the control unit 7 causes the grinding feed means 20 to lower the grinding means 10 at a grinding feed speed of 0.5 mm / s. Set in advance. The control of the grinding feed means 20 is performed by the control unit 7.

  As shown in FIG. 1, in the grinding apparatus 1, the plate-like workpiece W is sucked and held by the holding table 2, and the holding table 2 rotates in the direction of arrow A, for example. At the same time, the turntable 3 rotates to position the holding table 2 below the grinding means 10.

  Next, the grinding feed means 20 lowers the grinding means 10 toward the plate-like workpiece W held on the holding table 2. At this time, the control unit 7 controls the grinding feed unit 20 so that the grinding unit 10 descends at a grinding feed rate of 10 mm / s, for example. Then, the grinding of the plate-like workpiece W is started when the grinding wheel 15 comes into contact with the plate-like workpiece W held on the holding table 2. When the grinding wheel 15 comes into contact with the plate-like workpiece W shown in FIG. 1, the load detection means 5 detects the load value of the grinding load applied to the plate-like workpiece W.

  When the grinding operation is started, the determination unit 6 shown in FIG. 1 reads the value of the load detection means 5 and determines whether or not the load value of the grinding load applied to the plate-like workpiece W is unloaded (step). S1).

  When the determination unit 6 determines that the load value is not unloaded, under the control of the control unit 7, the grinding feed unit 20 raises the grinding unit 10 at a predetermined speed, and the plate-like workpiece W and the grinding wheel 15 are moved. A non-contact state is set (step S4).

  On the other hand, if it is determined that the load value is unloaded, the grinding feed means 20 lowers the grinding means 10 at a predetermined speed, and the grinding workpiece 15 is brought into contact with the plate workpiece W to perform grinding (step S2, second step). Grinding feed process). Then, while grinding, the determination unit 6 continues to read the load value of the load detection means 5 and determines whether or not the load value reaches a predetermined threshold value (step S3).

  When the read load value does not reach the predetermined threshold value, the grinding feed means 20 further lowers the grinding means 10 and continues grinding the plate-like workpiece W (step S2).

  On the other hand, when the read load value reaches a predetermined threshold value, the grinding feed means 20 raises the grinding means 10 at a predetermined speed (step S4, first grinding feed process). Then, the determination unit 6 determines whether or not there is time to repeat the raising of the grinding means 10 in the first grinding feed process and the lowering of the grinding means 10 in the second grinding feed process (step S5).

  When the determination unit 6 determines that there is no time to repeat, the control unit 7 raises the grinding unit 10 to the grinding feed unit 20 and ends the grinding.

  On the other hand, when the determination unit 6 determines that there is a time to repeat, the process returns to step S1 and if the load value of the grinding load applied to the plate-like workpiece W is no load, the grinding means 10 is lowered (step S2, first step). 2), if the load value is no load, the grinding means 10 is raised (step S4, first grinding feed step). In this manner, the first grinding feed process and the second grinding feed process are alternately repeated based on the value of the grinding load under the control of the control unit 7.

  When the plate-like workpiece W is ground in such a procedure, the height position of the grinding means 10 and the grinding load value change under the relationship shown in FIG. 3, for example.

  Explaining along FIG. 3, when the grinding feed means 20 lowers the grinding means 10 from the control start time t0, and when the grinding wheel 15 comes into contact with the plate-like workpiece W and grinding starts at the grinding start time t1. Further, the grinding means 10 descends (phase Z0). In phase Z0 in which the grinding means 10 descends while grinding, the value of the grinding load gradually increases (phase L0).

  As the grinding load value increases in this way, the grinding load value reaches a predetermined threshold value at the time of switching t2. Then, the grinding means 10 starts to rise (phase Z1, first grinding feed step), and the grinding load value decreases (phase L1).

  When the grinding means 10 rises in phase Z1 and the grinding wheel 15 does not come into contact with the plate-like workpiece W, the grinding load becomes 0 (no load) at the time of switching t3. Then, the grinding means 10 turns downward (phase Z2, second grinding feed step), and the value of the grinding load increases (phase L2).

  Thus, when the grinding load increases and reaches the threshold value at the time of switching t2 ′, the grinding means 10 starts to increase (phase Z1 ′, first grinding feed process), and the value of the grinding load decreases (phase L1). ').

  When the grinding means 10 rises in phase Z1 'and the grinding wheel 15 does not contact the plate-like workpiece W, the grinding load becomes no load at the time of switching t3'. Then, the grinding means 10 turns downward (phase Z2 ', second grinding feed step), and the value of the grinding load increases (phase L2').

  When the value of the grinding load increases and reaches the threshold value at time-out t4, the grinding means 10 starts to increase. And the repetition time of a 1st grinding feed process and a 2nd grinding feed process becomes zero, and also the grinding means 10 raises and grinding is complete | finished.

  Thus, in the grinding apparatus 1, the control unit 7 can control the grinding feed of the grinding feed means 20 while detecting the grinding load applied to the plate-like workpiece W by the load detection means 5. When the determination unit 6 determines that the value of the grinding load has reached a predetermined threshold value in the first grinding feed step, the grinding means 10 is raised at a predetermined grinding feed speed to interrupt the grinding, and the second In this grinding feed process, when the judgment unit 6 judges that the load value of the grinding load has become unloaded due to this increase, the grinding means 10 can be lowered at a predetermined grinding feed speed to resume grinding. Thus, the plate-like workpiece W can be ground while alternately repeating grinding interruption and resumption. Therefore, it is possible to prevent the grinding wheel 15 from losing its self-generated blade action due to an excessive rotational load applied to the motor that rotates the grinding wheel 15, and the workpiece is a plate-like workpiece formed of a difficult-to-grind material. Even if there is, grinding can be continued.

1: Grinding device 100: Base 101: Standing base 2: Holding table 2a: Table base 2b: Holding portion 2c: Holding surface 2d: Supporting portion 3: Turntable 4: Rotating shaft 5: Load detecting means 6: Determination Unit 7: Control unit 8: Rotating shaft 9: Suction source 10: Grinding means 11: Spindle 12: Spindle housing 13: Mounter 14: Grinding wheel 15: Grinding wheel 20: Grinding feed means 21: Ball screw 22: Motor 23: Shaft support 24: Moving base 30: Belt 31: Motor

Claims (2)

A holding table for holding the plate-like workpiece; a grinding means for grinding the plate-like workpiece by bringing a grinding wheel into contact with the plate-like workpiece held on the holding table; and a direction approaching the holding table and the holding table A grinding method using a grinding device comprising: a grinding feed means for grinding and feeding the grinding means in a separating direction;
The holding table or the grinding means is provided with a load detection means for detecting a grinding load applied to the plate-like workpiece when the grinding means is ground and fed by the grinding feed means.
The load detection means detects the grinding means by lowering the grinding means to bring the grinding wheel into contact with the plate-like workpiece held on the holding table, and further lowering the grinding means at a predetermined grinding feed speed. A first grinding feed step of raising the grinding means at a predetermined speed by the grinding feed means when a load value to be reached reaches a predetermined threshold;
When the load value detected by the load detection means becomes no load by raising the grinding means in the first grinding feed step, the grinding means is lowered at a predetermined grinding feed speed by the grinding feed means. A second grinding feed step,
A grinding method in which the first grinding feed step and the second grinding feed step are alternately repeated. A holding table for holding a plate-like workpiece, a grinding means for grinding the plate-like workpiece held on the holding table, and grinding-feeding the grinding means in a direction approaching the holding table and a direction away from the holding table A grinding device comprising a grinding feed means,
A load detecting means which is disposed on the holding table or the grinding means and detects a grinding load applied to the plate-like workpiece when the grinding means is ground and fed by the grinding feed means;
When the load value detected by the load detecting means reaches a predetermined threshold value, the grinding means is raised at a predetermined speed by the grinding feed means, and the load detecting means detects by the rising of the grinding means. A control unit that controls the grinding means to lower the grinding means at a predetermined speed when the load value becomes no load, and alternately and repeatedly raises and lowers the grinding means by the grinding feed means; ,
Grinding device equipped with.

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