JPH05285806A - Grinding control of work - Google Patents

Abstract

PURPOSE:To provide a surface grinding control method of a processed article capable of simultaneously improving productivity, quality and a yield. CONSTITUTION:This surface grinding control method is furnished with a conditioning process to grind by way of using a first grinding liquid as well as applying first grinding pressure, a grinding process to grind with second grinding pressure which is higher than the first grinding pressure following this conditioning process and a finishing process to grind by way of using third grinding pressure which is lower than the first grinding pressure and by way of using a second grinding liquid which is thicker in concentration than the first grinding liquid.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for controlling grinding of a work suitable for surface grinding of a metal disk, for example.

[0002]

2. Description of the Related Art An aluminum disk used as a hard disk is known as a metal disk that requires surface grinding. The surface grinding of the aluminum disk is performed by pressing a grinding grindstone against the surface to be ground with a predetermined grinding pressure, and relatively rotating the aluminum disk and the grinding grindstone while supplying a grinding liquid to the surface to be ground.

[0003]

In the above-described surface grinding of the workpiece, when the concentration of the grinding liquid is low, the grindability is excellent, but the surface roughness of the surface to be ground is deteriorated. On the other hand, when the concentration of the grinding fluid is high, the surface roughness of the surface to be ground is good, but the grindability is deteriorated, and in this case, the so-called droop on the inner and outer peripheral edges of the aluminum disk becomes large. Will end up.

In order to reduce the sagging of the inner and outer peripheral edges of the aluminum disk, it is sufficient to lower the above-mentioned grinding pressure, but in this case, the grindability will be significantly deteriorated.
Therefore, when performing the grinding work while maintaining the same grinding conditions,
There is a problem that a so-called trade-off relationship occurs between the productivity and the quality and the yield. This invention is
The present invention has been made under the circumstances described above, and an object thereof is to provide a work grinding control method capable of improving not only productivity but also quality and yield.

[0005]

According to the method of controlling grinding of a workpiece of the present invention, while the grinding pressure is set to the first grinding pressure,
First using a first grinding liquid having a predetermined concentration as the grinding liquid
After the leveling step of grinding the surface to be ground of the work for a predetermined time of, and the leveling step, only the grinding pressure is switched to the second grinding pressure higher than the first grinding pressure and set to a desired value. A grinding step of grinding the surface to be ground by an amount of grinding, and subsequent to the grinding step, the grinding pressure is switched to a third grinding pressure lower than the first grinding pressure and is set, and the grinding fluid is the first grinding fluid. And a finishing step of grinding the surface to be ground for a second predetermined time by using a second grinding liquid having a higher concentration.

[0006]

According to the present invention, the grinding of the work is carried out by first carrying out the leveling step for the first predetermined time. Here, the first grinding liquid is used, and the grinding pressure is the first grinding pressure. It is set. After this, the grinding step is carried out subsequent to the leveling step, but here, only the grinding pressure is set to the second grinding pressure higher than the first grinding pressure until the desired grinding amount is obtained. Is carried out. After that, when the grinding process shifts to the finishing process, the grinding liquid is switched to the second grinding liquid having a higher concentration than the first grinding liquid, and the grinding pressure is the third grinding lower than the first grinding pressure. The pressure is set and the finishing process is continued for a second predetermined time.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to FIG. 1, a grinding system is shown in its entirety and comprises a grinding machine 2. The grinder 2 has a base 4, on which a thrust bearing 6 and a radial bearing 8 are provided.
A hollow rotating shaft 10 is rotatably provided upright. A drive gear 12 is attached to the outer peripheral surface of the rotating shaft 10,
The drive gear 12 is meshed with the output gear 16 of the speed reducer 14. An electric motor, that is, a grindstone motor 18 is connected to the input shaft of the speed reducer 14, and the grindstone motor 18 is connected to the power supply side via a speed controller 20 and a make contact C1 of the first relay R1. The speed controller 20 can variably control the rotation speed of the grindstone motor 18 according to a command from the speed setting switch 24.

At the upper end of the rotary shaft 10, the turntable 2
6 is fixed, and a work table 28 is fixedly attached to the turntable 26. Work table 2
An annular aluminum disk, that is, a work W can be mounted on the work piece 8 through a jig. A grindstone holder 30 made of a circular plate is arranged above the work table 28, and the grindstone holder 30 is supported by an air cylinder 32. That is, the air cylinder 32 is arranged in a vertical posture, and the upper end of the cylinder outer cylinder is supported via the support post 34, while the piston rod 36 of the air cylinder 32 extends downward and its tip is It is connected to the upper surface of the grindstone holder 30.

On the lower surface of the grindstone holder 30, a grinding grindstone 38 is provided.
Is attached in a detachable manner, and this grinding wheel 3
8 has a disk shape. The air cylinder 32 is of a reciprocating type, and both pressure chambers (not shown) of the air cylinder 32 are connected to a cylinder solenoid valve, that is, a cylinder SV44, by pneumatic lines 40 and 42. This cylinder SV44
1 comprises a 4-port 2-position directional control valve as is apparent from FIG. 1, and therefore the pneumatic lines 40 and 42 are connected to the two input / output ports of the cylinder SV44, respectively. Further, one of the remaining two ports of the cylinder SV44 is connected to the air pressure source 46, and the other port is open to the atmosphere.

The cylinder SV44 has its first solenoid 44a connected to the make setting C2 of the second relay R2, and its second solenoid 44b connected to the power source side via the make contact C3 of the third relay R3. There is. An electro-pneumatic converter is inserted in the pneumatic line 40 that connects the cylinder SV44 and the air cylinder 32. The electro-pneumatic converter controls the pressure adjustment valve 48 and the set pressure of the pressure adjustment valve 48. And the piezoelectric element 50 for determining. The piezoelectric element 50 is made of Saramix that expands and contracts according to a supply voltage, and the piezoelectric element 50 is connected to a programmable controller 54 via a D / A converter 52.

On the other hand, the grinding machine 2 is provided with a grinding fluid feeding device 5
6 is provided, and the feeding device 56 has a plurality of pans 58 for the grinding liquid. These pans 58 are arranged on the upper surface of the grindstone holder 30 at equal intervals in the circumferential direction, and the bottom surfaces of these pans 58 and the lower surface of the grinding wheel 38 are connected via a plurality of passages 60. Has been done. That is, as is clear from FIG. 2, each passage 6
The upper end of 0 is opened to the bottom surface of the tray 58, and the lower end thereof is opened to the lower surface of the grinding wheel 38.

A branch pipe 62a on one end side of the liquid feed pipe 62 is connected to each of the trays 58, and the other end side of the liquid feed pipe 62 is branched to a pair of branch pipes 62b and 62c to form a first pipe. And the second tanks 64 and 66, respectively. The first and second tanks 64 and 66 store a grinding liquid containing, for example, a water-soluble emulsified oil.
The concentrations of the grinding fluids of No. 4 are different from each other. In particular,
The first grinding liquid L1 in the first tank 64 contains 1% by weight of water-soluble emulsified oil, and the second grinding liquid L2 in the second tank 66 is
It contains 5% by weight of water-soluble emulsified oil.

The branch pipe 62b of the liquid feed pipe 62 has a first
A tank solenoid valve, that is, a first tank SV68 is inserted, and a solenoid of the first tank SV68 is connected to a power source side via a make contact C4 of a fourth relay R4. On the other hand, a second tank solenoid valve, that is, a second tank SV70 is inserted in the branch pipe 62c of the liquid supply pipe 62, and the solenoid of this second tank SV70 is passed through the make contact C5 of the fifth relay R5. It is connected to the power supply side.

Further, a liquid feed pump 72 is inserted in the liquid feed pipe 62, if necessary.
Can be omitted when the first and second tanks 64 and 66 are arranged at a level position sufficiently higher than the grindstone holder 30 described above. Also, the grindstone holder 30
Since it can be moved up and down by the air cylinder 32, a part of the liquid supply pipe 62 is composed of a flexible coil hose 62d so as to allow the whetstone holder 30 to move up and down.

Programmable controller 54 described above
On the input side of, the start button (SB) of the grinding system
A switch 74, a finishing time setting button 76, and a grinding amount setting button 78 are connected, and a grinding amount detecting sensor 82 is connected to an input side of the switch 74 via an A / D converter 80. As shown in FIG. 1, the grinding amount detection sensor 82 is composed of a displacement sensor arranged inside the rotary shaft 10 of the grinding machine 2, and its detector 84 has a turntable 26, a work table 28, and a work table 28. Penetrate the grinding wheel 38,
It is in contact with the lower surface of the grindstone holder 30.

On the other hand, on the output side of the programmable controller 54, in addition to the above-mentioned piezoelectric element 50, the above-mentioned first
To fifth relays R1 to R5 are respectively connected. The programmable controller 54 controls the operation of the grinding system to carry out the surface grinding of the work W according to the flowcharts shown in FIGS. 3 to 5. Below, in addition to the flowcharts, the timing chart of FIG. Connect the procedure for surface grinding with reference.

First, in step S1 of FIG. 3, various conditions are set. Specifically, the finishing time setting button 76 and the grinding amount setting button 78 set the finishing time and the grinding amount, respectively, and these are stored in the memory of the programmable controller 54. Then, after setting the work W on the work table 28 of the grinder 2, the start button switch 74 is turned on to perform step S.
If the determination result of 2 is positive (YES), then the flag F2 is set to 1
Is set to (step S
3). At this point, the determination result of step S3 is negative (N
O), and proceeds to the next step S4. In this step, from the programmable controller 54 to the fourth relay R
4, the make contact C4 is closed and the first tank SV68 is opened. At this time, the second tank SV70
The fifth relay R5 on the side is not energized, so that the second tank SV70 is in the closed state. Further, when the liquid feed pump 72 is incorporated in the liquid feed device 56 of the grinding system, the liquid feed pump 72 is driven in this step. Therefore, the thin first grinding liquid L1 in the first tank 64 is supplied to the grinding machine 2 through the liquid supply pipe 62.

In the next step S5, the programmable controller 54 energizes the first relay R1 to close its make contact C1 and the grindstone motor 18 is driven via the speed controller 20. The whetstone motor 18 is driven by the rotary shaft 10 via the speed reducer 14 and the gears 16 and 12.
That is, the work table 28 is rotated, and as a result, the work table 28 is rotated.
The grinding wheel 38 is rotated relative to the work W above. Here, as shown in FIG. 6, the rotation speed of the grinding wheel 38 is gradually increased by the operation of the speed controller 20 from the ON operation of the start button switch 74, that is, the start of the driving of the wheel motor 18, and It is maintained at a constant rotation speed N1 (for example, 50 rpm).

When the relative rotation of the grinding wheel 38 is started, the programmable controller 54 causes the second relay R to move.
2 is energized and its make contact C2 is closed, whereby the cylinder SV48 is switched to the ON position (step S6). At the ON position of the cylinder SV48, compressed air from the air pressure source 46 is supplied to one pressure chamber of the air cylinder 32 via the pressure adjusting valve 48, and the piston rod 36 of the cylinder is expanded.

Thereafter, in the next step S7, similarly to step S3 described above, it is sequentially determined whether or not the flag F2 is set to 1 and whether or not the flag F1 is set to 1 in step S8. However, at this point, the determination results of these steps are all negative, and the process proceeds to the next step S9. In this step, the first grinding pressure control is executed. Specifically, by a calculation in the programmable controller 54, a predetermined voltage is supplied from the programmable controller 54 to the piezoelectric element 50 of the pressure regulating valve 40 described above via the D / A converter 52. The set pressure of the adjusting valve 40 is controlled. Here, this set pressure is the pressing force of the grinding wheel 38 applied to the work W by the extension of the air cylinder 32,
That is, as shown in FIG. 6, the grinding pressure of the grinding wheel 38 turns on the start button 74, that is, the cylinder SV4.
After gradually increasing from the time of turning on of No. 8, the pressure is controlled to be maintained at a relatively low pressure, that is, the first grinding pressure P1 (for example, 100 g / cm2).

In the next step S10, the timer in the programmable controller 54 is set to determine whether or not the first predetermined time T1 has elapsed from the start of the first grinding pressure control (step S11). Here, the first predetermined time T1 is preset in the program itself of the programmable controller 54 in the range of 5 sec to 20 sec. Specifically, the first predetermined time T1 is determined based on an empirical value within the above range.

Therefore, the routine from step S4 to step 9 is repeatedly executed until the determination result of step S11 becomes positive. In this grinding, the grinding liquid L1 having a low concentration is used as the grinding liquid as described above, and the grinding pressure is set to the relatively low first grinding pressure P1. , The work W leveling process. That is, in the leveling process, a thin grinding liquid L1
Although the surface roughness of the surface to be ground of the work W is poor, the use of the above makes the sag of the outer peripheral edge and the inner peripheral edge of the work W good. Therefore, the leveling step is performed to improve the grindability after this. It is a warm-up process.

In carrying out the leveling process, the grinding pressure is not sharply raised to the first grinding pressure P1,
Since the pressure is gradually increased toward the first grinding pressure P1, the shock applied to the work W can be reduced and the quality thereof is not impaired. After the above-mentioned break-in step is performed for the first predetermined time T1, step S11
If the result of the determination is positive, the process proceeds to step S12, the flag F1 is set to 1, and the above-mentioned timer is reset.

After this, when the steps after step S2 are repeatedly executed, the determination result of step S8 becomes positive, so that from this step S8 to step S13 of FIG.
And the steps following this step are performed. In step S13, the second grinding pressure control is performed. Here, the voltage supplied to the piezoelectric element 50 of the pressure regulating valve 48 is changed based on the calculation output of the programmable controller 54, and the set pressure switching control is performed. Be seen. Specifically, as shown in FIG. 6, the set pressure of the pressure adjusting valve 48 by the piezoelectric element 50 is such that the grinding pressure gradually rises from the first grinding pressure P1 and is higher than the first grinding pressure P1. Is controlled to be maintained at a high second grinding pressure P2 (for example, 200 g / cm2). Therefore, also here, the work W is not suddenly shocked, and the work W can be prevented from being damaged.

In the next step S14, the grinding amount X of the workpiece W detected by the above-mentioned grinding amount detecting sensor 82 is read, and it is judged whether or not the grinding amount X has reached the set value X1 (step S14). S15). Here, the set value X1 is
It is already given to the programmable controller 54 from the above-mentioned grinding amount setting button 78, and normally the set value X1
Is set in the range of 25 μm to 40 μm.

Therefore, after the above-described break-in step, steps S4 to S8 are performed, and steps S13 and subsequent steps are repeated. Here, as is clear from FIG. 6, since the grinding liquid L1 having a low concentration is used and the grinding pressure is also set high,
The process here is a substantial grinding process. That is, in this grinding step, grinding is performed with emphasis on the grindability of the work W so that the grinding amount X of the work W reaches the set value X1 in a short time. Usually, the grinding step is performed for 40 seconds to 120 seconds.
ec will be continued.

When the grinding amount X of the work W reaches the set value X1,
If the determination result of step S15 is positive, step S1
At 6, the flag F2 is set to 1. After this,
When the steps after step S2 are repeatedly executed, the determination result of step S3 becomes positive. In this case, therefore, step S4 is bypassed, that is, step S4.
After performing step S17 in place of 4, then step S5
Will proceed to.

In step S17, the programmable controller 54 stops energizing the fourth relay R4 to open the make contact C4, and conversely, energizes the fifth relay R5 to close the make contact C5. As a result, the first tank SV68 is closed and the second tank SV70 is opened. Therefore, in this case, the thick second grinding liquid L2 in the second tank 66 is supplied to the grinding machine 2 through the liquid supply pipe 62.

After that, when step S7 is reached, the determination result is positive again, so that the process proceeds from step S7 to step S18 in FIG. In this step, the third grinding pressure control is performed. Here, the voltage supplied to the piezoelectric element 50 of the pressure regulating valve 48, that is, the set pressure of the pressure regulating valve 48 is switched based on the arithmetic output of the programmable controller 54. Control is performed. Specifically, as shown in FIG. 6, the set pressure of the pressure control valve 48 is such that the grinding pressure gradually decreases from the second grinding pressure P2 and is lower than the first grinding pressure P1. The grinding pressure is controlled to be maintained at P3 (for example, 50 g / cm2).

In the next step S19, the aforementioned timer is set again, and it is judged whether or not the timer value has reached the finishing time T2 (step S20). Here, the finishing time T2 is set by the above-mentioned finishing time setting button 76, and usually takes a value in the range of 15 sec to 40 sec.
Therefore, steps S17 to S7, and then step S18 are performed until the determination result of step S20 becomes positive.
The following steps will be repeated,
In this step, as shown in FIG. 6, since the grinding liquid L2 having a high concentration is used as the grinding liquid and the grinding pressure thereof is also set to the low third grinding pressure P3, Grinding is a finishing process. In other words, in the finishing process, the grinding is performed with the focus on improving the quality by improving the surface roughness of the surface to be ground of the work W, suppressing the sagging of the outer peripheral edge and the inner peripheral edge, regardless of the grindability. Will be seen.

When the determination result of step S20 is positive,
In step S21, preparation for stopping the grindstone motor 18 is performed. Here, as shown in FIG. 6, due to the action of the speed controller 20 described above, the relative rotational speed of the grindstone motor 18, that is, the grinding grindstone 38, is gradually decreased toward 0, and the grindstone motor 18 is stopped. It is determined whether or not (step S22). If the determination result here is negative, the process returns to step S2 and the subsequent steps are repeated. However, if the determination result is positive, the steps after step S23 are performed.

In step S23, the programmable controller 54 stops energizing the second relay R2 and opens the make contact C2, while energizing the third relay R3.
The make contact C3 is closed, and as a result, the cylinder SV4
4 is switched from the on position to the off position. Therefore, the piston rod 36 of the air cylinder 32 contracts, and the grinding wheel 38 is separated from the surface to be ground of the work W.

In the next step S24, the programmable controller 54 stops energizing the fifth relay R5, opens the make contact C5, and opens the second tank SV70.
Close. Therefore, at this point, the supply of the grinding fluid to the grinding machine 2 is stopped. Then, in the next step S25,
When the timer is reset and the flags F1 and F2 are both reset to 0, the grinding of the work W is completed.

The grinding of a new work W is carried out by repeating the procedure described above. The present invention is not limited to the above-described embodiment, and various modifications can be made. For example, the values of the first to third grinding pressures and the concentrations of the first and second grinding fluids are not limited to those illustrated, and can be set appropriately according to the work.

Further, the grinding machine itself is not limited to the one shown in FIG. 1, and the concrete structure can be variously modified.

[0036]

As described above, according to the grinding control method of the present invention, the grinding liquids having different concentrations are selectively used, and the grinding pressure is also changed. The grinding process and the finishing process can be performed under the optimum grinding conditions for the work. Therefore, it is possible to improve the grinding of the work, that is, the productivity thereof, and at the same time, the quality thereof can be improved and the yield thereof can be greatly improved, and further, the consumption of the concentrated second grinding liquid can be reduced with the improvement of the productivity. It has an excellent effect.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram showing a grinding system.

FIG. 2 is an enlarged view of a part of the grinder of FIG.

FIG. 3 is a part of a flowchart showing a procedure for grinding a work.

FIG. 4 is a part of a flowchart showing a procedure for grinding a work.

FIG. 5 is a part of a flowchart showing a procedure for grinding a work.

FIG. 6 is a timing chart showing a grinding procedure of a work.

[Explanation of symbols]

 2 Grinding machine 32 Air cylinder 38 Grinding wheel 44 Cylinder SV 48 Pressure adjusting valve 50 Piezoelectric element 54 Programmable controller 64 First tank 66 Second tank 68 First tank SV 70 Second tank SV 76 Finishing time setting button 78 Grinding amount setting button 82 Grinding amount detection sensor L1 1st grinding fluid L2 2nd grinding fluid W Work

Claims (1)

[Claims] 1. A grinding grindstone is pressed against a surface to be ground of a workpiece with a predetermined grinding pressure, and while the grinding liquid is supplied to the surface to be ground, the workpiece and the grinding grindstone are relatively rotated to grind the surface to be ground. In the grinding method, if the grinding pressure is set to the first grinding pressure and the first grinding liquid having a predetermined concentration is used as the grinding liquid to grind the surface to be ground for the first predetermined time. And a grinding step of setting only the grinding pressure to a second grinding pressure higher than the first grinding pressure and setting the grinding pressure, and grinding the surface to be ground by a desired grinding amount. Subsequent to the grinding step, the grinding pressure is set by switching to a third grinding pressure lower than the first grinding pressure, while the second grinding liquid is used by using a second grinding liquid having a concentration higher than that of the first grinding liquid. During the specified time of Grinding control method of a work, characterized by comprising a lower step.