JPS6263047A - Precision working method - Google Patents

Abstract

PURPOSE:To work precisely a work in working a hub or the like mounting a disk of a magnetic disk device by setting the origin to the upper limit position of a tool rest with a sensor to work always the work with a tool lowered from this origin. CONSTITUTION:A position in which a measuring sensor 30 is changed over to withdraw somewhat a tool from a working portion W1 of a work is set to the origin of an origin sensor 31 by vertically moving a tool rest 28 with a pulse motor 29. In working a work W, the tool rest 28 is vertically withdrawn until the origin sensor 31 detects the origin, and a tool 32 is lowered a predetermined amount from a position of the origin to work the work W. That is, the tool rest 28 is lifted by the pulse motor 29 which is stopped at the position in which the origin sensor 31 is changed over. And in this predetermined position are lowered the tool rest 28 and tool 29 by the pulse motor 29 to grind or polish the working portion W1 of the work W.

Description

[Detailed Description of the Invention] [Summary] The position where the tool is somewhat retracted from the machining part of the workpiece is set using the origin sensor, and after always detecting the origin position with the origin sensor, the pulse motor is used to move the tool a predetermined amount. By advancing the tool by the same amount, machining with high dimensional accuracy is possible.

[Industrial application field]

The present invention relates to a method for processing an article that requires high dimensional accuracy, and more particularly to a method for processing an upwardly facing surface of a predetermined dimension from a reference position on the upper surface with high precision.

[Products subject to precision processing]

FIG. 8 is a side view of the internal structure of a magnetic disk device that requires precision machining. On a hub 1 driven by a spindle motor M, disks 2 and spacing rings 3 are mounted alternately. A carriage 6 equipped with a magnetic head 5 for reading and writing information on both sides of each disk 2 is mounted on the device reference surface 4, and a voice coil motor 7 drives the disk 2...・Driven back and forth in the radial direction.

In the case of a floating type magnetic head suitable for high-speed reading and writing, the magnetic heads 5 read and write by floating only a minute gap of 1 μm or less from the disk surface. In low-speed devices that read and write with the magnetic head in contact with the disk surface, the contact pressure between the magnetic head and the disk surface must be constant. Therefore, it is necessary that the dimension in the height direction between the reference surface 4 on which the carriage 7 is placed and the disk 2 . . . be assembled according to the designed value.

[Conventional technology]

When manufacturing equipment that requires such high precision, it is generally necessary to process each part so that the dimensional accuracy is within specified limits.
I am trying to assemble those parts. However, while assembling such a large number of parts, dimensional errors accumulate, so it takes a lot of effort to achieve the required dimensional accuracy.

Therefore, recently, as shown in Fig. 9, after assembling the hub 1 on which the disks 2... are mounted to the frame 8, the hub 1 is rotated by a spindle motor M, and the dimension between it and the reference surface 4 is adjusted. While measuring parallelism, the hub 1 is cut so that the distance between the hub 1 and the reference surface 4 is a predetermined height. If the hub 1 is rotated and cut after being assembled in this manner, rotation of the hub 1 in the vertical direction can also be prevented.

[Problem that the invention seeks to solve]

However, in order to cut such a workpiece, it is necessary to perform machining so that the dimensions between the reference surface 4 of the device and the machined surface of the hub 1 of the workpiece are highly accurate.

Also, since both the reference surface 4 and the machined surface of the workpiece face upward, the hub 1
It is necessary to accurately position the tool for machining the reference surface 4 in the height direction (Z direction) and then clamp it before machining.

A technical object of the present invention is to solve such problems in conventional precision machining methods and to realize a method that can accurately machine a workpiece so that the machined surface of the workpiece has a predetermined dimension with respect to a reference surface.

[Means for solving problems]

FIG. 1 is a side view illustrating the basic principle of the precision machining method according to the present invention. 9 is a base of the processing device, and a pulse motor 29 for positioning the tool rest 28 is attached thereto. A holder (3
5), the tool 32 is attached, and the workpiece W in front of it is attached.
It is driven back and forth in the direction by an actuator (not shown). A machining part measuring sensor 30 is attached to the tool rest 28 at a position on the workpiece W side, and is capable of measuring the machining part -1. An origin sensor 31 for detecting the vertical origin of the tool rest 28 is provided on one of the tool rest 28 and the base 1.

First, by moving the tool rest 28 up and down with the pulse motor 29, the measurement sensor 30 is switched at a position where the tool 32 can be somewhat retracted from the workpiece processing section-1.
Set as the origin of the origin sensor 31. When processing the workpiece W, the tool rest 28 is retracted upward until the origin sensor 31 detects the origin, and the tool 32 is lowered by a predetermined amount from that position to process the workpiece W.

[Effect]

Since the origin sensor 31 is set to switch at a position slightly above the machining section-1 of the workpiece W, the pulse motor 29 raises the turret 2 and the origin sensor 31 switches off. The pulse motor 29 is stopped at the new position. This operation is always performed before machining the old machining section. Then, before starting machining, the tool 29 is always located at a constant position defined by the origin sensor 31. Then, at this fixed position, the pulse motor 29 lowers the tool rest 28 and the tool 29, and the machining part of the workpiece W -
Grind or polish 1. The amount of processing in this case is determined by the amount of feed by the pulse motor 29. In other words, the machining distance from the origin position of the machining part is known in advance, and in order to lower the tool 29 by the machining amount, the pulse motor 2
It is also known how many steps 9 should be driven.

Therefore, depending on the number of driving steps of the pulse motor 29, processing can be performed from the origin position to a position of a predetermined size.

〔Example〕

Next, how the precision machining method according to the present invention is actually implemented will be explained using examples. FIG. 2 is a perspective view of the workpiece clamping mechanism in the precision processing apparatus, and FIG. 3 is a longitudinal sectional view of the clamping section.

In the figure, a workpiece W to be processed is indicated by a chain line, and a hub 1 and a frame 8 on which a spindle motor for driving the hub 1 is mounted are visible.

Reference numeral 9 denotes a base of the positioning clamp mechanism, and two columns 10 and 11 are fixed to the base 9.

Guide shaft 12.13 provided in this strut 10.11
A slide block 14 is supported and can slide vertically along two guide shafts 12 and 13. A reference pin 15.15 is provided above the support column 10.11 at a predetermined height H from the base 9, and the upper limit of the slide block 14 is defined by this reference pin 15. The slide block 14 is accurately formed so that a contact surface 14a that contacts the reference bin 15 and a lower workpiece contact surface 14b are parallel to each other.

The slide block 14 is equipped with a tapered pin 16 whose position in the horizontal direction (X-Y direction) is accurately determined. FIG. 4 shows a third enlarged view of the configuration of this taper pin 16.
It is a partial cross-sectional side view of the AA' direction of a figure. An arm 17 extends from the slide block 14, and this arm 1
A taper pin 16 is attached to the tip of 7 in a downward direction. Moreover, it is retracted by a return spring 18, and can be lowered against the return spring 18 by operating an actuator 19 such as an air cylinder.

Free bearings 20 are attached to the base 9 at four locations as movable means for freely moving horizontally with the workpiece W mounted thereon. Further, a clamp block 21 on which a workpiece W is placed and pushed up from below is provided at a lower position than the free bearing 20.

Note that both ends of the slide block 14 are connected to a piston rod of a fluid pressure cylinder 23 below the base 9 via a drive loft 22 . Also, the clamp block 21
is connected to a piston rod of a fluid pressure cylinder 25 via an oscillating mechanism 24.

Next, the positioning clamp operation by this device will be explained.

When starting positioning clamp, slide block 1
4 is pushed up by a drive rod 22, and the taper pin 16 is retracted by a return spring 18. The clamp block 21 has been lowered to the lowest position below the free bearing 20.

(1) In this state, first place the work W on the free bearing 20, but at this time, the center 1 of the hub 1 of the work W
c is located substantially below the taper pin 16, and the slide block 14 is placed so that the reference surface 4 is located below the contact surface 14b of the slide block 14. Alternatively, when the workpiece W is placed on the free bearing 20, means such as a stopper 27 may be arranged in the X and Y directions of the base 9 so that this rough positioning can be automatically performed. You can leave it there.

(2) With the taper pin 16 projected by the actuator 19, the slide block 14 is gradually lowered by its own weight. Then, first, the tip of the taper pin 16 is fitted into the center hole 1c of the hub 1 of the workpiece W. At this time,
If the center of the taper pin 16 and the center of the center hole 1c do not match exactly, the work W
Since the center hole 1c is guided by the taper pin 16, the workpiece W moves in the X and Y directions until the center of the center hole 1c and the taper pin 16 coincide with each other. Positioning is performed.

(3) The slide block 14 continues to descend, but when the taper pin 16 hits the center hole 1c and a pressure greater than the force required for positioning in the X-Y directions is applied, the taper pin 16 is forcibly pushed in. Then, the contact surface 14b of the slide block 14 comes into contact with the reference surface 4 of the work W, thereby restricting the movement of the work W.

(4) Next, lift the clamp block 21 from below the free bearing 2o and press it against the lower surface of the work W. Then, the slide block 14 is further pushed up, and with the workpiece W sandwiched between the slide block 14 and the slide block 14, the slide block 14 is pushed up until the abutment surface 14a of the slide block 14 comes into contact with the reference pin 15. Then, since the clamp block 21 cannot be raised any further, the work W
is clamped between the clamp block 21 and the slide block 14.

As a result, the workpiece W is positioned in the horizontal direction (X-Y direction), and since the contact surface 14a of the slide block 14 is at a predetermined height H from the surface of the base 9, the workpiece W is positioned in the height direction (Z direction). ) has also been positioned.

+51. Therefore, if the actuator 19 is turned off and retracted by the return spring 18 so that the taper pin 16 is separated from the workpiece W, the hub 1 can be rotated by the spindle motor M. By setting a tool on the base 9 and rotating the hub 1, the hub 1 can be machined to the dimensions shown in FIG.

To unclamp the workpiece W after completing a predetermined process, the clamp block 21 is gradually lowered, and the clamp block 21 is lowered by its own weight with the workpiece W and the slide block 14 placed thereon. When the workpiece W descends to the free bearing 20, it is placed and supported by the free bearing 20, and the clamp block 21 continues to descend to the lowest position. The slide block 14 is raised by the hydraulic cylinder 23 and returned to its initial state in preparation for the next positioning clamp.

As shown in FIG. 3, an auxiliary base 26 is placed below the base 9.
A hydraulic cylinder 25 for driving the clamp block 21 is attached to the auxiliary base 26 . This clamp block 21 pushes up the workpiece W and the slide block 14, but the slide block 14
A guide shaft 12.13 equipped with a reference pin 15 against which the
The lower end of is supported by the auxiliary base 26 mentioned above. The lower end of the support column 10.11 is fixed to the base 9.

[Example of precision processing method]

As shown in FIG. 2, a support 33 is erected on the support 10 side of the base 9, and a vertically movable tool rest is built into the support 33. 5 to 7 show examples of precision machining equipment for carrying out the method of the present invention, in which FIG. 5 is a partial cross-sectional side view, and FIG.
The figure is a plan view, and FIG. 7 is a front view. As shown in FIG. 5, a pulse motor 29 is attached to the base 9, and a feed screw 34 rotated by the pulse motor 29 is screwed into a tool rest 28 that moves up and down in a column 33. Therefore, when the feed screw 34 is rotated by the pulse motor 29, the tool post 2 moves up and down depending on the direction of rotation.

A tool holder 35 is horizontally movably supported on the tool rest 28, and a tool 32 is attached to the tool holder 35. In other words, the motor 3 mounted on the turret 28
An eccentric cam 37 rotating at 6 presses the upper end 38 of the tool holder 35 in the force direction of arrow a, that is, toward the workpiece W. Therefore, when the eccentric cam 37 is rotated by the motor 36, the tool holder 35 moves forward and cuts the processing portion 1 of the workpiece W. The tool holder 35 is returned to its original position by a tension coil spring 39 attached to the tool holder 35.
It will be held at 39.

A measurement sensor 30 is attached to the front of the tool post 28, that is, on the workpiece W side, and an extension pin 40 is attached to the lower end of the measurement sensor 30.
The lower end of is in contact with the processed portion-1 of the workpiece W, and the measurement is performed. A hood 41 for removing chips is attached to the tool rest 28 so as to surround the tool 32, and a discharge hose 43 is attached to the discharge port 42 as shown in FIG.
It is sucked and discharged in the direction of arrow a2.

On the other hand, a blade origin sensor 31 is attached to the tool rest 28 facing upward, and a post 44 attached to the base 9 has a
A micrometer head 45 is attached to finely adjust the origin of the tool post 28.

To perform precision machining with this device, first the origin of the tool rest 28 is set, the origin position of the tool 32 is determined, and then the workpiece W is set and machining begins. To set the origin,
First, instead of the workpiece W, a flat plate with a highly flat upper surface is clamped using the clamping mechanism shown in FIGS. 2 and 3. Then, a block that is slightly thicker (for example, exactly 2 mm) than the size of the workpiece W (dimension h in FIG. 9) is placed on this flat plate.

Then, pin 4 of the measurement sensor 30 is placed on the top surface of this block.
The pulse motor 29 lowers the tool post 28 until the lower end of the sensor 30 contacts the sensor 30 and just switches.

In this state, by adjusting the micrometer head 45, the sensor 31 for setting the origin is set to switch exactly. In other words, for the tool post 28, this origin position is the upper limit position, and the tool post 28 always moves from this origin position.
8 is lowered, and the machining of the machining section-1 begins. Therefore, it is necessary to set the height of the tool 32 at this origin position so that it is always higher than the machining portion IAI of the workpiece W.

To align the tip of the tool 32 with the lower end of the extension pin 40 of the measurement sensor 30, the pulse motor 29 lowers the tool post 28 until the tip of the tool 32 hits the block.

The measurement sensor 30 is mounted by adjusting the vertical position of the metal fitting 46 and fixing it at a position where the lower end of the extension pin 40 comes into contact with the block surface.

For workpieces where the dimension from the reference surface 4 to the hub 10 surface, which is the machining part 1 in FIG. Workpieces can be processed immediately. In other words, the pulse motor 29 causes the origin sensor 31 to
until the tool rest 28 comes into contact with the micrometer head 45.
Raise it and set it to the upper limit position. And work W
is clamped and positioned so that the reference surface 4 of the work W is in contact with the contact surface 14b of the slide block 14.

Then, the processed portion-1 of the workpiece W is located directly below the pin 40 of the measurement sensor 30. As mentioned above, the dimensions are 2
Since I set the origin by placing a mm thick block, I set the turret 2.
By lowering 8 by 2 mm from the original position, it can be processed to the desired size. The amount of descent 2++u++ of the tool 32 can be set by the number of steps of the pulse motor 29, so depending on the number of drive pulses of the pulse motor 29, processing can be performed by exactly 2n+n+. In addition, instead of machining 2+++++++ at a time, the operation of lowering the tool rest 28 a little, moving the tool 32 back and forth with the motor 36 while the work W is rotating to perform machining, and then lowering it a little again and then machining is repeated.

If the machining allowance is known in advance, subsequent machining can be performed efficiently. For this purpose, a pin 40 is attached to the processing part H of the workpiece W.
The tool rest 28 is machined from the origin position until it comes into contact with the tool rest 28. The number of pulses supplied to the pulse motor 29 at this time determines the vertical position of the machining section, and it becomes clear how many more pulses need to be supplied to complete the machining to a predetermined dimension.

When the machining is completed, the rotation of the workpiece W is stopped, and the tool rest 28 is lowered by the pulse motor 29 until the pin 40 of the measurement sensor hits the machining part 1 of the workpiece W with the tool 32 retracted. By counting the number of pulses supplied to the pulse motor 29 at the time, it is possible to check whether the machining is being performed accurately.

It is difficult to align the tip of the tool 32 and the lower end of the extension pin 40 on the block as described above.

Therefore, in reality, instead of the above-mentioned "h+2 mm" block, a "h+1 mm" block is placed, and the tool rest 28 is lowered until the tip of the tool 32 just touches the top surface of the block. Then, the amount of descent from the origin position until the tip of the tool 32 comes into contact with the block surface can be determined by the number of pulses supplied to the pulse motor 29. In other words, the error in the vertical direction between the lower end of the extension pin 40 and the tip of the tool 32 is detected. Therefore, when driving the pulse motor 29 when machining the workpiece W, machining is started after calculating the number of pulses to be supplied so that this error is offset.

Note that the measurement sensor 30 may be integrally constructed with the extension pin 40, or the origin sensor 31 may be attached to the post 44 side, and the micrometer Rad 45 may be attached to the tool post 28 side.

〔Effect of the invention〕

As described above, according to the present invention, the origin sensor 31 of the tool post 28 sets the origin that is the upper limit position of the tool post 28, and the workpiece W is always machined by lowering the tool 32 from this origin position. do. Therefore, as long as the origin is set, the workpiece can be machined with high precision until the predetermined dimensions are achieved with simple operations.

You can also easily set the origin.

[Brief explanation of drawings]

Fig. 1 is a side view explaining the basic principle of the precision machining method according to the present invention, Figs. 2 to 4 show the clamping mechanism used in the method of the present invention, and Fig. 2 is a perspective view showing the entire structure. 3 is a longitudinal sectional view of the clamp part, FIG. 4 is a sectional view of the main part, FIGS. 5 to 7 show an apparatus for carrying out the precision machining method of the present invention, and FIG. 6 is a plan view, FIG. 7 is a front view of essential parts, FIG. 8 is an internal side view of an apparatus requiring precision machining, and FIG. 9 is a side view illustrating a precision machined product. In the figure, 9 is the base, W is the workpiece, Wl is the processing part,
28 is a tool post, 29 is a pulse motor, 30 is a measurement sensor, 31 is an origin sensor, and 32 is a tool. Patent Applicant: Fujitsu Limited Representative, Patent Attorney Minoru Aoyagi Column 4 and Menkoku No. 6 Jitsuj Bao I I's 4th Baba's Funeral Seitan I Revised No. 7

Claims (1)

[Claims] A measurement sensor (30) for measuring the machining surface (W1) of the workpiece (W) is mounted on a tool post (28) that is reciprocated in the machining direction of the workpiece (W) by a pulse motor (29). Install the
In addition, an origin sensor (31) is provided to detect the origin of the tool rest (28) with respect to the base (9) side, and a measurement sensor (30) is installed at a position where the tool (32) can be somewhat retracted from the workpiece machining section (W1). The switching state is set as the origin of the origin sensor (31), and then the tool post (28) is retracted until the origin sensor (31) detects the origin, and the tool (32) is moved from that position.
A precision machining method characterized by machining a workpiece (W) by advancing it by a predetermined amount.