JPS6327960B2 - - Google Patents

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a method for adjusting a step motor encoder, and more specifically,
The present invention relates to a step motor encoder adjustment method for setting the correspondence between the static angular position of a step motor coupled with a rotary encoder and the detected angular position from the rotary encoder.

[Conventional technology]

First, in a conventional step motor encoder in which a rotary encoder is combined, as shown in FIGS. 2 to 4, a step motor 1 and a rotary encoder 2 are integrated.
The motor is comprised of excitation windings 3 and 4, a permanent magnet 6 fixed to the output shaft 5 of the rotor, a yoke 7 surrounding the permanent magnet 6, and the like, and is housed in a housing 8. 9 is a bearing that supports the output shaft 5.

The rotary encoder 2 includes a rotary plate 11 which is fixed to an output shaft 5 and has a large number of first slit groups 10 formed along the circumferential direction, and a rotary plate 11 which is disposed opposite to the rotary plate 11 and whose slit shape is similar to that of the first slit group 10. 1st
The slit group includes a slit plate 13 on which an appropriate number of second slit groups 12 with different pitches are formed, and a light receiving element 15 that receives light from the light emitting element 14 through the slits of the first and second slit groups 10 and 12.
Then, the signal from the light receiving element 15 is processed and the output shaft 5
The light emitting element 14 and the light receiving element 15 are mounted on a support member 17, and the angular position can be adjusted by a slit plate 13 about the axis of the output shaft 5. ing. 18 is an output conductor of the rotary encoder 2, and 19 is a cover.

Here, the step motor 1 is a rotary machine that can be controlled in an open loop and rotates by a predetermined displacement amount by applying a predetermined pulse-like input. Then, by connecting the rotary encoder 2 to the output shaft 5 of the step motor 1 and processing the angular displacement detection signal from the rotary encoder, closed-loop control is achieved and more accurate control than the control of the step motor 1 alone is achieved. It is well known that this is possible. For this purpose, it is necessary to adjust the rest position of the step motor 1 and the detected position from the rotary encoder 2 to a constant positional relationship for control purposes.

The conventional method for such adjustment is to first energize the step motor 1 and put it in a stationary state, and then adjust the second slit group 12 to a specified state while checking the signal from the signal processing circuit 16 of the rotary encoder 2. Adjust the position, change the excitation resting position of the step motor 1 several times while temporarily fixing it, and when the specified state is reached, permanently fix the second slit group 12,
Step motor rest position and rotary encoder 2
Compatibility with detected position signals from

However, the conventional adjustment methods described above (1) require many adjustment points and are time-consuming; (2) the second slit 12
(3) Because the step motor 1 is rotated and the step motor 1 is temporarily fixed, and the step motor 1 is rotated and temporarily fixed again, there is a large physical instability factor. element is large, (4)
This method has drawbacks such as the need for a drive circuit for the step motor 1, which is expensive.

[Summary of the invention]

This invention eliminates the drawbacks of the conventional methods and stabilizes the output by simultaneously displaying the back electromotive voltage waveform generated by the step motor and the output waveform from the rotary encoder and adjusting them at the time level (angle). The present invention provides a step motor encoder adjustment method that can significantly reduce adjustment costs.

〔Example〕

Below, Fig. 1 and Fig. 2 showing an example of a conventional device are shown.
An embodiment of the present invention will be described with reference to FIGS.

As an example, a step motor 1 with a unipolar connection of 1.8 degrees per pulse has a rotation speed of 200 degrees.
When adjusting the step motor encoder when the pulse rotary encoder 2 is connected, the output shaft 5 is rotated at a certain constant rotation by the secondary rotational force, and the step motor 1 is adjusted as shown in FIG. Look at the back electromotive voltage waveforms 3A and 4B, and compare the output waveform C from the rotary encoder 2 displayed at the same time. Then, back electromotive voltage waveform 3
A and 4B are sinusoidal waveforms, and waveforms whose phases are shifted by 90 degrees are obtained. The apex P of this sine waveform is the resting position of the step motor 1 when it is energized in 4-phase 1, and the intersection Q between the waveforms 3A and 4B is its resting position when it is energized in 4-phase 2.

Utilizing such a phenomenon, by adjusting the angular position of the slit plate 13 and adjusting the position of the output waveform C of the rotary encoder 2 to correspond to point P or point Q, the rest angular position of the step motor 1 can be adjusted. and the detected angular position from the rotary encoder 2 can be made to correspond uniquely.

〔Effect of the invention〕

As described above, the present invention rotates the output shaft of the step motor using a secondary rotational force, and uses the correlation positional relationship between the back electromotive voltage waveform on the step motor side and the output waveform on the rotary encoder side to bring the step motor to a standstill. The positional relationship between the position and the detection position of the rotary encoder can be easily seen, and by displacing the second slit of the rotary encoder to displace the detection signal, the relationship between the detection position of the rotary encoder and the rest position of the step motor can be easily determined. Compatibility can be easily set.

In this way, a large number of adjustment points, which was a drawback of the conventional method, can be recognized at the same time by simultaneously displaying the output waveform, and adjustment can be achieved in the same way as single-point adjustment. Also, since it is a one-point adjustment method, there is no need to temporarily fix the second slit.
Adjustments can be made using equipment such as a secondary rotary device and an oscilloscope, significantly reducing adjustment work time and improving the economy of mass production.

[Brief explanation of the drawing]

FIG. 1 is an output waveform diagram in one embodiment of the present invention. 2 to 4 show a step motor having a conventional encoder, in which FIG. 2 is an external perspective view, FIG. 3 is a partial vertical sectional view, and FIG. 4 is a schematic perspective view of the main part. DESCRIPTION OF SYMBOLS 1... Step motor, 2... Rotary encoder, 3, 4... Excitation winding, 5... Output shaft, 6... Permanent magnet, 10... First slit group, 11... Rotating plate, 12
...Second slit group, 13...Slit plate, 14...Light emitting element, 15...Light receiving element, 16...Signal processing circuit.

Claims (1)

[Claims] 1. A rotating plate fixed to the output shaft of the step motor and forming a first group of slits along the circumferential direction;
a slit plate in which a second slit facing the first slit group is formed and can be rotated about the axis of the output shaft; a light emitting element and a light receiving element disposed opposite to each other with the first and second slits interposed therebetween; When adjusting the detection angle position of the rotary encoder, the back electromotive voltage waveform of the step motor generated by rotating the output shaft by a secondary rotational force and the output waveform of the rotary encoder are displayed at the same time level. A method for adjusting a step motor encoder, which comprises observing and adjusting the displacement of the slit plate so that the output waveform of the rotary encoder has a predetermined correspondence with a stationary point of the step motor on the back electromotive voltage waveform.