JP3745536B2 - Double-head surface grinding machine - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a double-head surface grinding apparatus for grinding both surfaces of a workpiece in parallel.
[0002]
[Prior art]
Conventionally, as a double-sided surface grinding device for grinding both surfaces of a wafer-like workpiece made of, for example, a hard and brittle material cut by a wire saw, a pair of rotating grindstones are arranged so that their grinding surfaces are parallel to each other. It has been. In this grinding apparatus, a workpiece is arranged at a processing position between both rotary whetstones, and the grinding surfaces of both rotary whetstones are rotated in contact with both surfaces of the workpiece, so that both surfaces of the workpiece are ground simultaneously. ing.
[0003]
[Problems to be solved by the invention]
However, in this conventional double-sided surface grinding apparatus, when a plurality of workpieces are repeatedly ground, the ground surfaces of both rotary grindstones gradually wear and become sharp and the grinding resistance increases. As a result, there has been a problem that the grinding efficiency and the grinding accuracy are lowered.
[0004]
In addition, if the grinding surfaces of the two rotating wheels wear with different degrees as the workpiece is ground, and the sharpness of these grinding surfaces is different, the grinding accuracy of the workpiece will be significantly reduced, and the workpiece will be warped. There was a problem that occurred.
[0005]
The present invention has been made paying attention to such problems existing in the prior art. The main purpose of the present invention is to provide a double-head surface grinding apparatus that can accurately detect the sharpness reduction of the grinding surface of both rotary grinding wheels and can prevent the grinding efficiency and the grinding accuracy from being lowered.
[0006]
A further object of the present invention is to provide a double-head surface grinding apparatus capable of preventing the sharpness difference between the grinding surfaces of both rotary grinding wheels and preventing the possibility that the grinding accuracy of the workpiece is remarkably lowered. It is to provide.
[0007]
[Means for Solving the Problems]
In order to achieve the above object, in the invention described in claim 1, a pair of rotating grindstones are arranged to face each other so that their grinding surfaces are parallel, and both surfaces of the workpiece are paralleled by the grinding surfaces of both rotating grindstones. In a double-head surface grinding apparatus for grinding, a detecting means for detecting the power consumption of a rotating motor for rotating each rotating grindstone and a difference between the power consumptions of the rotating motors detected by the detecting means are calculated. And a control means for controlling the power consumption difference to converge to a predetermined value or zero, and the control means adjusts the amount of coolant supplied to each rotating grindstone to thereby reduce the power consumption difference to a predetermined value. Alternatively, it is controlled to converge to zero .
[0011]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
As shown in FIG. 1, the double-head surface grinding apparatus includes a lower frame 11. An intermediate frame 12 is fixed on the lower frame 11, and an upper frame 13 is fixed on the intermediate frame 12. The lower frame 11 is provided with a lower grindstone rotating / lifting mechanism 14 and a work support mechanism 15, and the upper frame 13 is provided with an upper grindstone rotating / lifting mechanism 16.
[0012]
The grinding wheel base 25 of the lower grinding wheel rotation raising / lowering mechanism 14 is equipped with a lower rotating grinding wheel 17 and a lower rotating motor 18 for rotating the grinding wheel 17, and a grinding surface 17 a is formed on the upper surface of the lower grinding wheel 17. . The upper rotary lifting mechanism 16 is equipped with an upper rotary grindstone 19 and an upper rotation motor 20 for rotating the upper rotary grindstone 19, and a grinding surface 19 a is formed on the lower surface of the upper rotary grindstone 19.
[0013]
The rotational axis of the lower rotating grindstone 17 is disposed on an extension of the rotational axis of the upper rotating grindstone 19, and the grinding surface 17 a of the lower rotating grindstone 17 is disposed in parallel to the grinding surface 19 a of the upper rotating grindstone 19. ing. The upper and lower whetstone rotation elevating mechanisms 16 and 14 are provided with a lifting motor (not shown), and the lifting and lowering feeding of the upper and lower whetstones 19 and 17 is controlled by the lifting motor.
[0014]
The lower rotating grindstone 17 is provided with a lower coolant supply mechanism 21 and includes a lower coolant supply amount adjusting valve 22 as shown in FIG. The upper rotating grindstone 19 is provided with an upper coolant supply mechanism 23 and similarly includes an upper coolant supply amount adjusting valve 24. The coolant is supplied to the grinding surfaces 19a and 17a of the upper and lower grindstones 19 and 17 by the upper and lower coolant supply mechanisms 23 and 21. The coolant supply amount adjusting valves 22 and 24 are provided with flow meters 41 and 42 for measuring the coolant supply amount.
[0015]
Next, the work support mechanism 15 will be described in detail. As shown in FIG. 2, the support base 27 is disposed on the lower frame 11 between the upper and lower whetstone rotation elevating mechanisms 16 and 14. A moving frame 28 is supported on the support base 27 via a pair of guide rails 29 so as to be movable in the horizontal direction. Then, the moving frame 28 is loaded with a moving motor (not shown), a loading position P1 for attaching and detaching the workpiece 30 shown by a solid line, and a machining position P2 for grinding the workpiece 30 shown by a chain line in FIG. To move between.
[0016]
A work holder 31 is rotatably supported on the moving frame 28, and a set hole 32 for detachably setting the work 30 is formed at the center thereof. An engagement protrusion 33 is provided in the set hole 32, and when the work 30 is inserted and set in the set hole 32, the cutout portion 30 a on the outer peripheral surface is engaged with the engagement protrusion 33. A rotation motor 34 is disposed on the moving frame 28. When the workpiece 30 is ground, the rotation motor 34 rotates the workpiece holder 31 to rotate the workpiece 30.
[0017]
As shown in FIGS. 2 and 3, a pair of mounting plates 35 are juxtaposed on the support base 27 and extend in the moving direction of the moving frame 28. On each mounting plate 35, a plurality of air pads 36 are arranged substantially in a line. Each air pad 36 includes a disk-shaped member 37 mounted on a mounting plate 35, and an air ejection hole 38 is formed at the center of the disk-shaped member 37. A nozzle 39 is connected to the air ejection hole 38 of each air pad 36, and an air supply source such as an air compressor (not shown) is connected.
[0018]
Then, the moving frame 28 is moved to the loading position P1, and the air supplied from the air supply source in the state where the work 30 is positioned and set in the set hole 32 of the work holder 31, is the nozzle of each air pad 36. 39 is ejected from the lower surface of the work 30 through the air ejection hole 38. As a result, the work 30 is held in a state of floating in the set hole 32.
[0019]
Subsequently, the moving frame 28 is moved from the loading position P1 of the workpiece 30 to the machining position P2 by a moving motor (not shown), and the workpiece 30 is conveyed to the machining position P2 while being lifted.
[0020]
Next, a circuit configuration of the double-head surface grinding apparatus configured as described above will be described. As shown in FIG. 7, the central processing unit (CPU) 43 controls the operation of each part of the grinding device. A read only memory (ROM) 44 stores various control programs necessary for the operation of the grinding apparatus. The random access memory (RAM) 45 temporarily stores data obtained with the execution of the control program. The CPU 43, ROM 44, and RAM 45 constitute a control means.
[0021]
The lower motor power consumption meter 46 constitutes detection means, detects the power consumption of the lower rotating motor 18 for rotating the lower rotating grindstone 17 during the grinding operation of the workpiece 30, and the detection result is sent to the CPU 43. input. The power consumption meter 47 for the upper motor constitutes detection means, detects the power consumption of the upper rotation motor 20 for rotating the upper rotating grindstone 19 during the grinding operation of the workpiece 30, and inputs the detection result to the CPU 43. To do. The operation panel 48 includes various operation keys and operation switches, and inputs operation signals of these operation keys and operation switches to the CPU 43.
[0022]
The display device 49 as a display means is composed of a CRT display or the like, and displays various detection data and the like based on the control of the CPU 43 during the grinding operation of the workpiece 30. That is, as shown in FIGS. 4 (a), 4 (b), 5 (a), and 5 (b), the display device 49 indicates the time series change of the power consumption detected by the power consumption meters 46 and 47. Display as a graph. 4A and 4B show time-series changes of the vertical rotation motors 20 and 18 for each machining cycle. 5A and 5B show time-series changes of the vertical rotation motors 20 and 18 for each workpiece 30 being processed.
[0023]
The display device 49 detects the amount of coolant supplied from both the upper and lower coolants with the flow meters 41 and 42 in addition to the time-series change in power consumption, and displays the time-series change in the coolant supply amount in a graph. To do. 6A and 6B show a time-series change in the coolant supply amount for each machining of the workpieces 30. FIG.
[0024]
In addition to the time-series change in power consumption, the display device 49 also displays the amount of coolant supplied from the upper and lower coolant supply mechanisms 23, 21. The CPU 43 controls the coolant supply amount by adjusting the upper and lower coolant supply amount adjusting valves 22 and 24.
[0025]
Next, the operation of the double-sided surface grinding apparatus configured as described above will be described based on the flowchart shown in FIG. This flowchart is executed under the control of the CPU 43 based on the control program stored in the ROM 44.
[0026]
In this double-head surface grinding apparatus, the grinding surfaces 19a and 17a of the upper and lower grinding wheels 19 and 17 are in contact with the upper and lower surfaces of the workpiece 30 in a state where the workpiece 30 set on the workpiece holder 31 is disposed at the machining position P2. Is done. In this state, the upper and lower grindstones 19 and 17 are rotated by the rotation motors 20 and 18, and the upper and lower surfaces of the workpiece 30 are ground simultaneously (S1).
[0027]
As described above, when the grinding operation of the workpiece 30 is started, the power consumption of the upper and lower motors 20 and 18 is detected by the upper and lower motor power consumption meters 47 and 46 (S2). Then, as shown in FIG. 4, the power consumption detected by these power consumption meters 46 and 47 is graphically displayed on the display device 49 in a time series change (S3).
[0028]
Subsequently, it is compared and determined whether or not each power consumption detected by each power consumption meter 46 and 47 is equal to or less than a reference value L1 stored in advance in the RAM 45 (S4). In this determination, as shown in FIG. 4, if the detected power consumption exceeds the reference value L1, the grinding operation is stopped after the machining of the workpiece 30 being machined (S5), and both vertical rotations are performed. Truing and dressing of the grinding surfaces 19a, 17a of the grindstones 19, 17 are performed (S11).
[0029]
If the detected power consumption is equal to or less than the reference value L1 in the determination of S4, the difference in power consumption between the up and down motors 20 and 18 (| P1-P2 | shown in FIG. 4) is calculated. (S6). Then, it is compared and determined whether or not the power consumption difference is within the set value L2 stored and set in advance in the RAM 45 (S7).
[0030]
In the determination of S7, if the power consumption difference is within the set value L2, the coolant supply amount is adjusted by adjusting the upper and lower coolant supply amount adjusting valves 24, 22 according to the power consumption difference. The power consumption difference is controlled to converge to a predetermined value or zero (S9). That is, when the power consumption of the upper rotation motor 20 is larger than the power consumption of the lower rotation motor 18, the coolant supply amount is increased by opening the upper coolant supply amount adjustment valve 24 or the like, and the upper rotation grindstone 19. Load is reduced. On the other hand, when the power consumption of the lower rotation motor 18 is larger than the power consumption of the upper rotation motor 20, the coolant supply amount of the lower coolant supply amount adjustment valve 22 is increased, and the lower rotation grindstone 17. The load is reduced. Here, the predetermined value means that the grinding accuracy may be improved by giving a certain difference to the power consumption of the vertical rotation motors 20 and 18 depending on the processing conditions.
[0031]
When the power consumption difference exceeds the set value L2, the power consumption cannot be converged to a predetermined value or zero even when excessive coolant is supplied, and the coolant supply amount becomes larger than the appropriate value. As a result, the grinding accuracy is reduced. In this case, the grinding operation is stopped (S8), and tooling and dressing are performed (S11). These operations (S2 to S9, S11) are repeated until grinding is completed. After the control operation is completed, the difference in power consumption between the vertical rotation motors 20 and 18 is calculated again.
[0032]
In this way, after the power consumption difference between the upper and lower rotary motors 20 and 18 is controlled to converge to a predetermined value or zero, the completion of the predetermined program operation is performed to determine the end of grinding of the workpiece 30. (S10). Then, the operations of S2 to S11 are repeatedly executed until the grinding of the workpiece 30 is completed, and all the operations are completed when the grinding of the workpiece 30 is completed.
[0033]
The effects that can be expected from the above embodiment will be described below.
In the double-head surface grinding apparatus of this embodiment, during the grinding operation of the workpiece 30, the power consumption of the rotation motors 18 and 20 for rotating the pair of rotary grindstones 17 and 19 is detected by a wattmeter 46 as a detection means. 47, respectively. Then, when the CPU 43 as the control means compares the power consumption of each of the rotation motors 18 and 20 detected by the power meters 46 and 47 with a preset reference value, the detected power consumption exceeds the reference value. A predetermined operation is executed. For this reason, even when the grinding surfaces 17a and 19a of the rotary grindstones 17 and 19 are gradually worn due to repeated grinding of the plurality of workpieces 30, the sharpness of the grinding surfaces 17a and 19a is accurately reduced. It can detect and can prevent that grinding efficiency and grinding precision fall.
[0034]
In the double-head surface grinding apparatus of this embodiment, when the detected power consumption exceeds the reference value L1 under the control of the CPU 43, the grinding operation is stopped, and the grinding surfaces 17a and 19a of the rotary grinding wheels 17 and 19 are truing and Dressing is performed. For this reason, it is possible to prevent the grinding operation of the workpiece 30 from being continued while the sharpness of the grinding surfaces 17a and 19a of the rotary grindstones 17 and 19 is lowered, and the grinding efficiency and the grinding accuracy are lowered. Can be reliably prevented.
[0035]
In the double-head surface grinding apparatus of this embodiment, during the grinding operation of the workpiece 30, the power consumption of the rotation motors 18 and 20 for rotating the pair of rotary grindstones 17 and 19 is detected by a wattmeter 46 as a detection means. 47, respectively. Then, the CPU 43 as the control means calculates the difference in power consumption of the motors 18 and 20 detected by the wattmeters 46 and 47, and the power consumption difference is controlled to converge to a predetermined value or zero. It is like that. For this reason, it is possible to prevent a difference in sharpness between the grinding surfaces 17a and 19a of the rotary grindstones 17 and 19 and to prevent a possibility that the grinding accuracy of the workpiece 30 is remarkably lowered.
[0036]
In the double-head surface grinding apparatus of this embodiment, the amount of coolant supplied to each of the rotating grindstones 17 and 19 is adjusted by the control of the CPU 43 so that the power consumption difference converges to a predetermined value or zero. . For this reason, by adjusting the amount of coolant supplied to each rotary grindstone 17, 19, the power consumption difference between the motors 18, 20 for both rotations can be quickly converged to a predetermined value or zero. , 19 can be surely prevented from causing a difference in sharpness between the ground surfaces 17a, 19a.
[0037]
-In the double-head surface grinding apparatus of this embodiment, the power consumption of each motor 18 and 20 detected by the wattmeters 46 and 47 is displayed on the display device 49 as display means. For this reason, it is possible to easily detect the sharpness reduction of the grinding surfaces 17a and 19a of the rotary grindstones 17 and 19 based on the display of the power consumption of the motors 18 and 20 for rotation. In addition, the difference in sharpness between the grinding surfaces 17a and 19a of the rotary grinding wheels 17 and 19 can be easily detected based on the power consumption difference based on the display of the power consumption of the motors 18 and 20 for both rotations.
[0038]
In the double-head surface grinding apparatus of this embodiment, when the power consumption difference between the motors for rotation 18 and 20 is compared with a preset set value under the control of the CPU 43, and the power consumption difference exceeds the set value L2. The grinding operation is stopped. For this reason, it is possible to prevent the grinding operation of the workpiece 30 from continuing while the sharpness difference of a predetermined value or more is generated between the grinding surfaces 17a and 19a of the rotary wheels 17 and 19, and the workpiece 30 is ground. It is possible to reliably prevent the possibility of causing a decrease in accuracy.
[0039]
In addition, this embodiment can also be changed and embodied as follows.
In place of the wattmeters 46 and 47 in the above-described embodiment, an ammeter or a voltmeter as a detecting means is provided so as to detect the current or voltage flowing in the upper and lower rotating motors 20 and 18.
[0040]
-It replaces with the wattmeters 46 and 47 in the said embodiment, and provides a torque meter as a detection means, and it is comprised so that the grinding torque of the upper and lower rotary grindstones 19 and 17 may be detected.
[0041]
In place of the wattmeters 46 and 47 in the above embodiment, a strain meter is provided as a detecting means, and the strain of the shaft supporting both the grindstones 19 and 17 is measured by this strain meter to detect the grinding resistance. .
[0042]
・ The double-sided surface grinding machine is equipped with a dressing mechanism and a truing mechanism, and when the detected power consumption exceeds the reference value L1, the truing and dressing of the rotating grindstones 17 and 19 are executed while the grinding operation is interrupted. To do.
[0043]
Furthermore, technical ideas other than the claims grasped by the above embodiment will be described below together with their effects.
The double-head surface grinding apparatus according to claim 1, further comprising display means for displaying power consumption of each rotation motor detected by the detection means.
[0044]
According to this configuration, it is possible to easily detect a reduction in the sharpness of the ground surfaces of the two rotating wheels based on the display of the power consumption of each rotating motor .
[0046]
- wherein the control means compares a preset value of power difference between the rotating motor when the power difference exceeds a set value, both the head surface grinding according to claim 1 for stopping the grinding operation apparatus.
[0047]
According to this configuration, it is possible to prevent the workpiece grinding operation from being continued in a state where a predetermined sharpness difference or more has occurred between the grinding surfaces of both rotary grinding wheels, and to reduce the grinding accuracy of the workpiece. The risk of incurring can be reliably prevented.
[0048]
【The invention's effect】
Since this invention is comprised as mentioned above, there exist the following effects.
According to the first aspect of the present invention, by adjusting the amount of coolant supplied to each rotating grindstone, the power consumption difference of the motors for both rotations can be quickly converged to a predetermined value or zero, so that both rotations It is possible to reliably prevent the difference in sharpness between the grinding surfaces of the grindstone. Accordingly, it is possible to prevent a possibility that the grinding accuracy of the workpiece is remarkably lowered.
[Brief description of the drawings]
FIG. 1 is a front view showing an embodiment of a double-head surface grinding apparatus of the present invention.
FIG. 2 is an enlarged plan view showing a workpiece support mechanism.
FIG. 3 is a partially enlarged cross-sectional view taken along line 3-3 in FIG.
FIGS. 4A and 4B are graphs showing time-series changes of a grindstone rotating motor.
FIGS. 5A and 5B are graphs showing time-series changes of a grindstone rotating motor.
FIGS. 6A and 6B are graphs showing time-series changes in the coolant supply amount.
FIG. 7 is a block diagram showing a circuit configuration of a double-head surface grinding apparatus.
FIG. 8 is a flowchart showing the grinding operation of the double-head surface grinding apparatus.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 14 ... Lower whetstone rotation raising / lowering mechanism, 15 ... Work support mechanism, 16 ... Upper whetstone rotation raising / lowering mechanism, 17 ... Lower whetstone, 17a ... Grinding surface, 18 ... Lower rotation motor, 19 ... Upper whetstone, 19a ... Grinding surface, 20 ... upper rotating motor, 21 ... lower coolant supply mechanism, 22 ... lower coolant supply adjustment valve, 23 ... upper coolant supply mechanism, 24 ... upper coolant supply adjustment valve, 30 ... work, 36 ... air pad, 40 ... air supply Quantity adjusting valve, 43 ... CPU constituting control means, 44 ... ROM constituting control means, 45 ... RAM constituting control means, 46 ... Power consumption meter for lower motor constituting detection means, 47 ... Detection means Constituting power meter for upper motor, 49... Display device as display means.

Claims (1)

In the double-head surface grinding apparatus in which a pair of rotating grindstones are arranged opposite to each other so that their grinding surfaces are parallel, and both surfaces of the workpiece are ground in parallel by the grinding surfaces of both rotating grindstones,
A detecting means for detecting the power consumption of the rotating motor for rotating each rotary grindstone and a difference between the power consumptions of the two rotating motors detected by the detecting means are calculated, and the difference in power consumption is set to a predetermined value or Control means for controlling to converge to zero,
The double-sided surface grinding apparatus , wherein the control means controls the power consumption difference to converge to a predetermined value or zero by adjusting the amount of coolant supplied to each rotating grindstone .

Images