JPH0442748A - Step motor provided with encoder - Google Patents

Abstract

PURPOSE:To stabilize holding of each terminal and to simplify the joint structure of motor lead wire by mounting the motor terminals and the encoder terminals on a same substrate. CONSTITUTION:Motor terminals 28A, 29A and an encoder terminal 34A are mounted on a same substrate 35. Consequently, the joint with lead wires 41 can be made compact and simple, workability can be improved at the time of assemblage, and the terminals 28A, 29A, 34A can be held in a stabilized state.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a stepping motor having an encoder for detecting the rotational position 1 of the motor.

[Conventional technology]

A stepping motor has multiple excitation phases (excitation coils)
By arranging the pole teeth of the stator and the rotor magnets magnetized at predetermined intervals in the circumferential direction to face each other, and applying pulse signals in a fixed order to each excitation phase, the rotor fixed to the motor shaft is kept constant. It is configured to rotate in degrees.

Therefore, the rotation angle of the motor is proportional to the number of pulse signals, and the rotation speed of the motor is proportional to the frequency of the pulse signals.

In this type of stepping motor, a step-out phenomenon may occur during high-speed operation, and in this case, it may be difficult to control the rotational position with high precision.

Therefore, conventionally, an encoder for detecting the rotational position of the motor is installed, and the timing of applying a pulse signal to the excitation phase is controlled based on the detection signal of the encoder, thereby improving the accuracy of motor rotation. A stepping motor with an encoder has been proposed.

The encoder used includes, for example, a coding disk such as a slit disk fixed to the motor shaft and a sensor such as a photointerrupter fixed to the motor case.

In addition to the above-mentioned coding disk, for example, a striped disk, a magnetized disk, etc. can be used, and in this case, a photoreflector, a magnetic sensor, etc. are used as the sensor.

It is also possible to use a pickup type encoder that includes a magnetic pole formed in the circumferential direction of a rotating part and a pickup placed on the outer periphery of the magnetic pole.

[Technical problem to be solved by the invention] However, in the conventional stepping motor with an encoder,
The motor terminals were connected to the motor terminal board or lead wires, and the encoder terminals were connected to different lead wires, each of which was taken out individually, making the structure of the motor lead wire connection complex and making it difficult to assemble. There was a problem in that the work required time and effort.

The present invention has been made in view of such conventional technical problems, and provides a stepping motor with an encoder that can simplify the structure of the motor lead wire connection part and improve workability during assembly. The purpose is to provide

[Means for solving problems]

The present invention provides a stepping motor equipped with an encoder consisting of a coded date plate fixed to a motor shaft and a sensor fixed at a predetermined position on the motor case side for detecting the rotation angle of the coded disk. To provide a stepping motor with an encoder that can simplify the structure of a lead wire connection part of the motor and improve workability during assembly by arranging a motor terminal and an encoder terminal on the same board. It is something.

〔Example] Hereinafter, the present invention will be specifically described with reference to a concave surface.

FIG. 1 is a longitudinal sectional view of an embodiment of a stepping motor with an encoder according to the present invention.

In FIG. 1, a bearing housing 11 is formed in the center of a drum-shaped motor case 10 with one end open, and a plate 12 is attached to the open end surface of the motor case 10.
is fixed by fixing means such as caulking 13, and another bearing housing 14 is formed at the motor shaft center of the plate 12.

The mounting plate 12 also serves as an end plate for sealing the open end surface of the motor case 10.

Bearing 1 press-fitted into each bearing housing 11.14
5.16, the motor shaft 17 is pivotally supported.

A rotor 18 is press-fitted and fixed to the motor shaft 17 in the motor case 10, and rotor magnets 19 magnetized to N and S poles are formed at a predetermined pitch in the circumferential direction on the outer periphery of the rotor 18. There is.

A yoke having pole teeth facing the rotor magnet 19 is disposed inside the motor, which is made up of a motor case 10 and a mounting plate 12.
A stack of excitation coils 20, 21 is arranged.

The yokes include a first outer yoke 22 fixed to the end face of the motor case 10, a first inner yoke 23 and a second inner yoke 24 joined back to back, and fixed to the inner surface of the plate 12. It is composed of a second outer yoke 25.

A first excitation coil 20 is installed inside the first inner and outer yokes 22.23 via a bobbin 26, and a second excitation coil 20 is installed inside the second inner and outer yokes 24.25 via a bobbin 27. A coil 21 is attached.

The bobbin 26.27 is made of an insulating material such as plastic, and parts 26A and 27A of the bobbin 26.27 protrude from the side surface of the motor case 10. Motor terminal member 28
．． 29 (4 or 6 in total) are led out.

A rotational force extraction means such as a pulley is fixed to the output side protrusion of the motor shaft 17.

Furthermore, an encoder 31 for detecting the angle and speed of motor rotation is attached to the outside of the motor case 10 on the side opposite to the output side.

This encoder 31 includes a coding disk (a slit disk in the illustrated example) 3 that is positioned and fixed on the motor shaft 17.
2 and a sensor (photointerrupter in the illustrated example) 33 positioned and fixed on the outer surface of the motor case 10.

The sensor 33 is connected to the motor terminal member 28.29.
The sensor terminal member 34 of the sensor 33 (consisting of a total of four encoder terminal members for power supply and signal) 34 is located on the same side as the motor terminal member 28 and 29. protruding in the same direction.

The sensor 33 connects positioning protrusions (not shown) formed at two locations on the mating surface to the motor case 10.
Positioning holes (not shown) formed at two locations on the end surface of
It is positioned and fixed by fitting into the motor case 10 and fastening with screws 38 to female screws 37 formed in the motor case 10 at the other two locations.

On the other hand, on the motor shaft 17, a plastic bearing member 39 having a face perpendicular to the axial center is press-fitted and fixed at a predetermined position in the axial direction, and a cord is press-fitted into the center hole of the motor shaft 17. The disk 32 is positioned and fixed by being pressed against the surface of the receiving portion 39 by a spring press ring 4Q which is also press-fitted.

The retainer ring 40 includes a spring portion that is inclined in a direction to prevent removal and whose tip is press-fitted into the motor shaft 17;
A flat annular portion is formed to press the coded disk 32 evenly against the receiver surface.

That is, the coded disc 32 is press-fitted with a center hole formed in itself to ensure coaxiality with the motor shaft, and the receiver of the member 39 is connected to the surface and the retainer having spring properties. By being pressed between the ring and the ring, the perpendicularity and axial position with respect to the motor shaft 17 are accurately ensured.

FIG. 2 is a side view taken from the line ■--■ in FIG. 1, and FIG. 3 is an end view on the output shaft side taken from the line ■--■ in FIG.

In FIGS. 1 to 3, as described above, each terminal member protrudes to substantially the same side in the circumferential direction of the motor, that is, a total of four or six motor terminal members 28, 29, and a total of four The sensor terminal member 34 of the book is formed of a conductive rod-shaped or plate-shaped metal having a predetermined rigidity.

Therefore, the motor terminal members 28, 29 and the sensor terminal member 34 are all fixed to the same substrate 35, and all the terminals formed at their tips, that is, the motor terminals 28A, 29A and the sensor terminal member 34, are fixed to the same substrate 35. one terminal 3
4A is provided on this common substrate 35.

The motor terminal 28 is connected to the motor terminal 28 via the circuit on the board 35.
A, 29A and sensor terminal 34A are connected to respective lead wires 41.

These connections are made, for example, by conductive coupling using solder or the like.

In addition, 42 and 42 in FIG. 3 indicate an east wire fitting for bundling each lead wire 41, and 43 indicates a connector for each lead wire 41.

A dustproof cover 36 for covering the encoder 31 is removably attached to the outer peripheral surface of the motor case 10.

This dustproof cover 36 is made of plastic molding and is fixed to the motor case 10 by a concave-convex engagement means (not shown) that utilizes its elasticity.

The purpose of the dustproof cover 36 is to prevent the cords such as slits formed in the coded disc 32 from becoming clogged with dust and the like, making the feed bank control of the rotation angle of the stepping motor unstable and inaccurate. belongs to.

According to the embodiment described above, the motor terminal member 28.
29 and the encoder-terminal member 34 are made to protrude to the same side, and the motor terminals 28A, 29A and the encoder-terminal member 34A are provided on the same substrate 35.
The connection part with the lead wire 41 can be made into a compact and simple structure, improving the workability during assembly, and it is equipped with an encoder that can hold each terminal 28A, 29A, 34A in a stable state. A stepping motor was obtained.

〔Effect of the invention〕

As is clear from the above description, according to the present invention, there is provided a coded disc fixed to the motor shaft, and a sensor fixed to a predetermined position on the motor case side for detecting the rotation angle of the coded disc. In a stepping motor equipped with an encoder consisting of a Provided is a stepping motor with an encoder that can improve workability during introduction.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view of an embodiment of a stepping motor with an encoder according to the present invention, and FIG. 2 is a line 1 shown in FIG.
FIG. 3 is an end view of the output side as seen from the line "---" in FIG. 1. Below, symbols representing main components in the drawings are listed. 10--Motor case, 12--Mounting plate, 17--Motor shaft, 18--...
Rotor, 19---Rotor magnet, 20.
21--...-excitation coil, 22.23.24.25
-------Yoke, 26.27--Bobbin, 28.29--Motor terminal member, 28 A, 2
9 A-----Motor terminal, 31 Coater% 32----- Coded disc (slit disc)
, 33----1 sensor (photo ink converter), 34---1 encoder 1 terminal, 34 A
-----------Encoder I (sensor one terminal),
35-1-----Board, 36------Dust-proof cover, 41----1 Lead wire, 43--1---Connector

Claims (2)

[Claims] (1) In a stepping motor equipped with an encoder consisting of a coding disk fixed to the motor shaft and a sensor fixed at a predetermined position on the motor case side for detecting the rotation angle of the coding disk, the motor A stepping motor with an encoder characterized in that a terminal and an encoder terminal are provided on the same board. (2) The stepping motor with an encoder according to claim 1, wherein the encoder is attached to the outside of the motor case.