JP3396723B2 - Manufacturing method of shade-type slit disk for optical encoder - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a hat-shaped slit disk in an optical encoder for detecting a rotation amount of a motor or the like. 2. Description of the Related Art Generally, as shown in FIG. 1, a motor for assembling a servo motor with an optical encoder is used as a motor for controlling a robot drive so as to perform highly accurate positioning. ing. In FIG. 1, as an optical encoder, a hat-shaped slit disk 2 is attached to a rotating shaft 1 of a motor, and a plurality of optical encoders are formed at equal intervals on a cylindrical peripheral surface of the hat-shaped slit disk 2. Photointerrupter 3 installed on substrate 4 so that slit 22 can be detected by light
Consists of In the figure, 5 is an armature, 6 is a stator made of a permanent magnet, 7 is a commutator, 8 is a brush, 9 is a flywheel, and 10 is a bearing. [0004] Usually, the cap-shaped slit disc 2 is formed by blanking the base material into a cap-shaped blank by pressing to form a cap-shaped disc 21 and then forming the cap-shaped disc 2.
A plurality of slits 22 are formed at equal intervals on one cylindrical peripheral surface.
(See FIGS. 2 and 3), but deformation of the formed cap-shaped disk 21 due to irregularity of roundness, uneven thickness, etc. is undeniable. Dimensional error occurs, and the accuracy of the encoder deteriorates. Conventionally, the machining accuracy of the hat-shaped slit disk 2 is increased by increasing the accuracy of blanking when forming the hat-shaped disk 21 and the accuracy of punching a plurality of slits 22. However, there is not much problem when the cap-shaped disk 21 is relatively large and the number of slits 22 is relatively small. However, the servo motor is miniaturized and the amount of rotation is finely detected to improve controllability. In order to meet the demand for raising the diameter, the diameter of the cap-shaped disk 21 is reduced (about 10 mm in diameter), and a slit 22
If a large number (approximately 60 to 70) is provided, it will not be possible to sufficiently cope with only blanking and slit punching processing techniques. [0007] A problem to be solved is that a blank is formed by blanking a base material into a hat shape by pressing, and then the cylindrical shape of the hat shape disk is formed. When manufacturing a cap-shaped slit disk for an optical encoder by punching and forming a plurality of slits at equal intervals on the peripheral surface, deformation of the cap-shaped disk causes dimensional errors accumulated during slit punching, resulting in poor encoder accuracy. It will be. In addition, when mass-producing a hat-shaped slit disk, there is a problem that the products are varied due to misalignment of each part of the line each time the production line is started. SUMMARY OF THE INVENTION The present invention is directed to blanking a disk-shaped slit disk having a small diameter and having a large number of slits formed on its peripheral surface so as to be suitable for mass production with high precision. was in line with the deformation of the umbrella-type disc, in order to perform good dimensional accuracy punching a plurality of slits in its circumferential surface, the steps of the bevel disc blanks vent while forming the reference portion from the substrate, the slit punching Removal device
As a test, several slips were
And forming the test pieces at equal intervals.
To rotate around a disk with a slit formed
The slit with the reference part as the reference position.
Step of detecting the detection signal and F / V converting the detection signal.
From the characteristics of the F / V converted signal
Determine the location of the abnormal pitch and the level of the abnormal
Pitch adjustment when forming slits at corresponding locations
And pitch by the slit punching device.
With adjustments made, a shade-shaped disc that becomes the actual product
A step of punching and forming a plurality of slits at equal intervals on the
Tsu is to take a flop. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS In a method for manufacturing a cap-shaped slit disk for an optical encoder according to the present invention, first, a cap-shaped disk 21 is formed from a plate-like base material by blanking. FIG. 4 shows a process of blanking the cap-shaped disk 21 while forming a reference portion from the base material 11 flowing in the line. In the base material 11, relief holes 14 are formed in four sides around a portion 13 to be punched beforehand designated by a pilot hole 12. As a first step, the portion 13 to be punched is pressed. Squeezed in a shade by the second
As a step, a center hole 16 is made in the portion 15 narrowed in the shape of a cap, and three reference holes 17 are made in predetermined places around the center hole 16. By cutting the squeezed portion 15 from the base material 11, a cap-shaped disc 21 is formed. Next, the formed cap-shaped disc 21
As a test, a plurality of (64) slits 22 are punched out and formed on the cylindrical peripheral surface of. FIG. 5 shows a slit punch for forming a plurality of slits 22 at equal intervals on the peripheral surface of a cap-shaped disk 21.
A punching device is illustrated, in which a cap-shaped disk 21 rotatably set on a pedestal 18 is rotated and positioned at a predetermined step set by a step motor 20 under the control of a controller 19, and a punch is formed. 23
Is operated, and the punch 23 itself is moved up and down by the air device 24, whereby the slits 22 are sequentially formed on the peripheral surface of the cap-shaped disk 21. At this time, for example, a stepping motor 20 of 100,000 pulses per rotation is used to perform rotational positioning at a fixed step of 1562 pulses, and the cap-shaped disk 2 is rotated.
64 slits 22 are formed on one peripheral surface. FIGS. 2 and 3 show the shed-shaped slit disk 2 in which a plurality of slits 22 are formed on the peripheral surface of the shed-shaped disk 21. Next, according to the present invention, using the cap-shaped slit disk 2 'obtained as a test product in accordance with the current operating condition of the production line as described above, the reference hole 17 is used as a reference. Find the indexing amount for slit punching. More specifically, as shown in FIG.
A master-type slit disk 2 ′ as a test product is mounted on a shaft 26 rotated by the rotary shaft 5 with its reference hole 17 at a predetermined position, and only one slit 22 is formed on the same rotary shaft 26. Disk 2
7, while obtaining a pulse signal per one rotation of the master disk 27 from the photointerrupter 31, the detection signal of the slit 22 detected by the photointerrupter 32 provided corresponding to the test disk 2 'is obtained. F / V conversion is performed by the F / V converter 28. Then, the oscilloscope 29 observes the characteristics of the F / V-converted signal of the test disk corresponding to the pulse signal per rotation of the master disk 27, and immediately observes the current operating state of the production line. Find the indexing amount of the slit punching performed. FIGS. 7 and 8 show the F of the test disk 2 'per one rotation (between pulse PP) of the master disk 26 observed by the oscilloscope 29. FIG.
Each example of the characteristic of the / V-converted signal is shown. In the case of FIG. 7, in the waveform A converted to the flutter characteristic by the F / V conversion, and at the point A where the waveform largely changes to the plus side, the test disk 2 ' It can be seen that the pitch of the slits 22 is abnormally narrow due to the deformation. At the position A on the peripheral surface of the test disk 2 ', it is necessary to make an adjustment so as to widen the pitch of the slits 22 in accordance with the degree to which the waveform changes to the plus side. In this case, A
The amount of the pitch adjustment of the slit 22 at the point (2) is calculated. In this case, for example, as described above, 156
When the rotational positioning is performed for every fixed step of two pulses to form 64 slits 22 on the peripheral surface of the cap-shaped disk 21, the step of forming the slit at the point A is one.
562 + α (α is the number of pulses corresponding to the degree to which the waveform changes to the plus side at the point A). In the case of FIG. 8, in the waveform B converted to the flutter characteristic by the F / V conversion, and at the point B where the waveform largely changes to the minus side, the test disk 2 ' It can be seen that the pitch of the slit 22 is abnormally wide due to the deformation. At the location B on the peripheral surface of the test disk 2 ', it is necessary to make an adjustment to narrow the pitch of the slits 22 in accordance with the degree to which the waveform changes to the minus side. In this case, the pitch adjustment amount of the slit 22 at the point B is determined according to the degree. In this case, for example, as described above, 156
When the rotational positioning is performed for every fixed step of two pulses to form 64 slits 22 on the peripheral surface of the cap-shaped disk 21, the step of forming the slit at the point B is one.
562-β (β is the number of pulses corresponding to the degree to which the waveform changes to the minus side at the point B). As described above, by appropriately adjusting the pitch of each portion, the indexing amount of the slit punching in accordance with the current operation state of the production line is obtained. It is also possible to easily calculate the pitch adjustment amount by the microcomputer and automatically set the indexing amount without the operator setting the indexing amount for the slit punching. . Finally, in the present invention, the data of the indexing amount of the slit punching obtained from the test disk 2 'in accordance with the current operation state of the production line is sent to the controller 19 in the apparatus shown in FIG. After setting, the stepping motor 19 performs step feed on the basis of the set indexing amount, and a hat-shaped disc as an actual product placed on the base 18 so that the reference hole 17 is at the reference position. A plurality of slits 22 are sequentially punched and formed on the peripheral surface of the cap-shaped disk 21 while rotating the 21. As the reference hole 17 provided in the cap-shaped disc 21, it is sufficient that one reference hole 17 is provided for rotational positioning. In this case, three reference holes 17 are provided.
Positioning when setting the cap-shaped disk 21 on the pedestal 18 is also performed. As described above, according to the present invention, at each start-up of a production line for mass-producing the cap-shaped disks 21 by blanking from the base material 11, a test-purpose disk obtained in accordance with the operating state of the line at that time. Since the amount of pitch adjustment of the slit 22 is obtained from the disk 2 'to obtain the amount of slit punching, an actual product is produced according to the deformation of the hat-shaped disk 21 mass-produced by the current line. Punching of a plurality of slits 22 on the peripheral surface of the cap-shaped disk 21 can be performed with high dimensional accuracy. As described above, according to the method of manufacturing the cap-shaped slit disk for the optical encoder according to the present invention , blanking is performed.
In accordance with the deformation of the formed cap-shaped disc,
Punching formation of a number of slits with high dimensional accuracy
In particular, a small diameter and a large number of slits
Ideal for mass-producing the formed cap-shaped slit disk
Become .

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a front sectional view showing a configuration example in which an optical encoder is incorporated in a servomotor. FIG. 2 is a plan view of a hat-shaped slit disk. FIG. 3 is a front view of a hat-shaped slit disk. FIG. 4 is a view showing a step of blanking a cap-shaped disc while forming a reference portion from a base material flowing in a line. [Fig. 5] A plurality of slits are equally spaced on the peripheral surface of a cap-shaped disc.
FIG. 1 is a simplified configuration diagram of a slit punching device for punching and forming a sheet . FIG. 6 is a simplified configuration diagram of an apparatus for obtaining a slit pitch adjustment amount based on a hat-shaped slit disk as a test product. FIG. 7 is a characteristic diagram showing an example of an F / V converted signal of the test disk per one rotation of the master disk. FIG. 8 is a characteristic diagram showing another example of the F / V converted signal of the test disk per one rotation of the master disk. [Description of Signs] 2 cap-shaped slit disc 2 'cap-shaped slit disc 21 for test cap-shaped disc 22 slit 3 photo-interrupter 31 photo-interrupter 32 photo-interrupter 11 base material 16 center hole 17 reference hole 18 pedestal 19 controller Reference Signs List 20 step motor 23 punch 25 motor 27 master disk 28 F / V converter 29 oscilloscope

Claims (1)

(57) [Claim 1] A step of blanking a cap-shaped disk while forming a reference portion from a base material, and a slit punching device.
As a test, use the
And forming the test pieces at equal intervals.
Around a shaft with a slit-shaped disk
Turn the slit with the reference part as the reference position.
A step of electrically detecting and F / V converting the detection signal.
From the characteristic of the F / V converted signal
The abnormal location of the pitch and the degree of the abnormality,
Pitch adjustment when forming slits at corresponding locations
Adjusting, and adjusting the pitch by the slit punching device.
After adjustment of the switch,
A plurality of slits formed at equal intervals by punching
A method of manufacturing a cap-shaped slit disk for an optical encoder , which is designed to take steps .