JP5445074B2 - Encoder and mounting method of encoder - Google Patents

Description

  The present invention relates to an encoder and an encoder mounting method.

  An encoder is known as a device that detects the number of rotations and rotation speed of a rotating body such as a rotating shaft of a motor (Patent Document 1). For example, the rotary encoder is used by being attached to a rotating shaft such as a motor. Further, as a specific configuration of the encoder, for example, a configuration for detecting the number of rotations using magnetism is known.

  The encoder having such a configuration rotates the code plate on which the pattern is formed integrally with the rotation shaft, irradiates the pattern with light from the light source, and transmits the light transmitted through the pattern or the light reflected by the pattern by the detection unit. To detect. Thereby, the absolute position within one rotation of the motor can be detected. As a specific configuration, for example, a rotating part provided with a code plate is fixed to a rotating shaft of a motor, and the rotating part is rotatably accommodated in a base part.

JP-A-3-287014

  However, in a general encoder, the base part and the rotating part may be fixed by a screw part in order to facilitate the work of attaching the encoder to the motor. Therefore, when attaching the encoder to the motor, it is necessary to loosen the threaded portion to separate the rotating portion and the base portion, and the attachment may be complicated.

  SUMMARY OF THE INVENTION An object of the present invention is to provide an encoder that can more easily separate a rotating part and a base part, and a method for attaching the encoder.

  In order to solve the above problems, the aspect of the present invention employs the following configuration corresponding to FIGS. In addition, in order to explain the present invention in an easy-to-understand manner, the description will be made in association with the reference numerals of the drawings showing an embodiment, but the present invention is not limited to the embodiment.

  The encoder (EC) according to an aspect of the present invention holds a rotating unit (1) having a magnet unit (1d) on which a magnetic pattern is formed, and a detecting unit (3) that detects a magnetic field of the magnet unit and performs the rotation. The base part (2) which accommodates a part, and the magnetic member (2c) integrally formed with the said base part are provided, It is characterized by the above-mentioned.

  An encoder mounting method according to an aspect of the present invention is an encoder mounting method using the encoder described above, in which the magnetic member is attracted to the magnet portion and the base portion is held by the rotating portion. A step of fixing the rotating unit to a measurement object (MB); and a step of separating the rotating unit and the base unit in a state where the rotating unit is fixed to the measuring object.

  ADVANTAGE OF THE INVENTION According to this invention, the encoder which can isolate | separate a rotation part and a base part more easily can be provided.

It is sectional drawing at the time of attachment of the encoder which concerns on embodiment of this invention. It is sectional drawing at the time of completion | finish of attachment of the encoder of FIG.

Hereinafter, a first embodiment of the present invention will be described with reference to the drawings.
The encoder of this embodiment is a device that detects the number of rotations and the rotation speed of a rotating body such as a motor. FIG. 1 is a cross-sectional view of the encoder according to the present embodiment when attached. FIG. 2 is a cross-sectional view of the encoder shown in FIG.
As shown in FIGS. 1 and 2, the encoder EC mainly includes a rotation unit 1, a base unit 2, and a detection unit 3.

  The rotating unit 1 is a member that rotates integrally with the drive shaft MS by being fixed to the drive shaft MS of the motor M to be measured by, for example, a bolt or the like. The rotating unit 1 is made of a metal such as aluminum. Centered on the rotation axis R of the rotation unit 1, an insertion hole 1 a into which the drive shaft MS of the motor M is inserted and a drive shaft MS inserted into the insertion hole 1 a are fixed to the center of the rotation unit 1. A bolt hole 1 b into which the bolt B is inserted is provided in parallel with the rotation axis R.

  In the insertion hole 1a, for example, a key groove (not shown) that fits with a key (not shown) provided on the drive shaft MS is formed. The rotating part 1 is fastened to the drive shaft MS of the motor M by a bolt B inserted through the bolt hole 1b. A code plate 1 c is provided on the surface of the rotating unit 1 on the detection unit 3 side, and a magnet unit 1 d is provided on the base unit 2 side of the rotating unit 1.

  The code plate 1 c is an annular member fixed to a surface of the rotating unit 1 that faces the detecting unit 3. In the code plate 1c, an optical pattern such as an absolute pattern or an incremental pattern is formed over the entire circumference in the rotation direction of the surface facing the detection unit 3. The code plate 1c reflects light applied to the optical pattern.

  The magnet part 1d is an annular neodymium iron-based sintered magnet fixed to the surface of the rotating part 1 facing the base part 2. A predetermined magnetic pattern is magnetized on the magnet portion 1d. As the magnetic pattern of the magnet portion 1d, for example, a magnetic pattern in which the inner peripheral side magnetic pole and the outer peripheral side magnetic pole are different and the inner peripheral side magnetic pole and the outer peripheral side magnetic pole are switched at 180 ° in the rotation direction is used. .

  The base portion 2 is formed in a substantially cylindrical shape, and has a housing portion 2a that houses the rotating portion 1 rotatably. The detection part 3 is attached to one end part of the base part 2, and the other end part is fixed to the motor main body (fixing part) MB via the flange part 2b. The base portion 2 is made of, for example, resin. The base portion 2 includes a back yoke (magnetic member) 2c and a back yoke support portion 2d.

  The back yoke 2c is made of, for example, a magnetic member such as metal, and is provided for the purpose of improving the magnetic force of the magnet portion 1d, improving the magnetic noise resistance, and the like. The back yoke 2c is formed in an annular shape corresponding to the shape of the magnet portion 1d. The back yoke 2c is fixed to the back yoke support portion 2d, and is disposed opposite to the magnet portion 1d at a position overlapping the magnet portion 1d around the drive shaft MS in plan view. The back yoke 2c is integrally formed with the base portion 2 so as to be embedded in the back yoke support portion 2d.

  The back yoke support portion 2d is provided inwardly in a direction perpendicular to the rotation axis R of the rotating portion 1 at a portion of the wall surface of the housing portion 2a on the motor M side. Thereby, the accommodating part 2a has a small inner diameter on the motor M side. The back yoke support portion 2d holds the back yoke 2c at a position facing the magnet portion 1d of the rotating portion 1.

  Here, the magnetic force of the magnet portion 1d is obtained by bringing the back yoke 2c of the base portion 2 into close contact with the magnet portion 1d by an attractive force acting between the back yoke 2c of the base portion 2 as shown in FIG. 2 is adjusted so that the rotating part 1 and the base part 2 can be integrated. Further, the magnetic force of the magnet portion 1d is such that the attractive force acting between the base portion 2 and the back yoke 2c is smaller than the fastening force of the bolt when the base portion 2 is fastened to the motor body MB with a bolt. It has been adjusted.

  Further, as shown in FIG. 1, the rotating unit 1 and the base unit 2 are fixed to the drive shaft MS of the motor M, and the base unit 2 is connected to the motor main body MB. In a state where they are not fastened but are held by the rotating part 1 and integrated, a gap G1 is formed between the end face of the base part 2 on the motor M side and the motor main body MB, and the base part 2 and the motor main body are formed. MB is separated

  Further, as shown in FIG. 2, the rotating unit 1 and the base unit 2 are fixed to the drive shaft MS of the motor M and the base unit 2 is mounted on the motor main body MB. In the state of being fastened and fixed, a gap G2 is formed between the magnet portion 1d of the rotating portion 1 and the back yoke support portion 2d and the back yoke 2c of the base portion 2, and the rotating portion 1 and the base portion 2 Are separated.

The detection unit 3 includes a substrate 3c on which an optical sensor 3a, a magnetic sensor 3b, an electronic component (not shown), and the like are mounted.
The optical sensor 3 a is provided at a position facing the code plate 1 c fixed to the rotating unit 1. The optical sensor 3a irradiates the optical pattern of the code plate 1c with light, detects the light reflected by the optical pattern, and transmits an electric signal based on the detection result to an arithmetic control unit (not shown). .

The magnetic sensor 3b is provided at a position overlapping the magnet portion 1d in plan view. The magnet unit includes a bias magnet (not shown), detects the direction of the combined magnetic field generated by the magnet unit 1d and the bias magnet, and transmits an electric signal based on the detection result to an arithmetic control unit (not shown). It has become.
The substrate 3c is fixed to the base portion 2 with, for example, bolts, so that the end portion of the base portion 2 opposite to the motor M is sealed. An opening 3d through which a bolt B for fixing the rotating unit 1 to the drive shaft MS of the motor M is inserted and removed is provided at the center of the substrate 3c.

In the encoder EC of the present embodiment, as shown in FIG. 2, the rotating unit 1 is fixed to the drive shaft MS of the motor M, the base unit 2 is fixed to the motor body MB, and the rotating unit 1 is connected to the detecting unit 3 and the back yoke. It is used in the state arrange | positioned between 2c.
When the drive shaft MS of the motor M rotates in this state, the rotating unit 1 fixed to the drive shaft MS rotates integrally with the drive shaft MS. When the rotating unit 1 rotates, the code plate 1c fixed to the rotating unit 1 also rotates in the same manner.

  When the code plate 1c rotates with the drive shaft MS, the optical pattern moves relative to the optical sensor 3a, and the light detected by the optical sensor 3a changes according to the optical pattern. The optical sensor 3a transmits an electrical signal corresponding to a change in light based on the detected change in the optical pattern to an arithmetic control unit (not shown).

When the rotating unit 1 rotates, the magnet unit 1d fixed to the rotating unit 1 also rotates in the same manner.
When the magnet unit 1d rotates with the drive shaft MS, the direction of the combined magnetic field of the magnet unit 1d and the bias magnet detected by the magnetic sensor 3b periodically changes due to the magnetic pattern of the magnet unit 1d. The magnetic sensor 3b transmits an electric signal corresponding to the change in the direction of the synthetic magnetic field to an arithmetic control device (not shown).

The arithmetic control device (not shown) processes the electrical signals transmitted from the optical sensor 3a and the magnetic sensor 3b, and calculates the rotational angle position, rotational speed, rotational speed, etc. of the drive shaft MS.
As described above, the encoder EC of the present embodiment can measure the rotational angle position, rotational speed, rotational speed, and the like of the drive shaft MS.

Also, in the conventional encoder, a back yoke made of a magnetic member is fixed to the rotating part for the purpose of improving the magnetic force of the magnet part provided in the rotating part and improving the magnetic noise resistance. The inertial force (inertia) of the rotating part may be a problem.
In the encoder EC of the present embodiment, the back yoke 2c is provided on the base portion 2 as described above. Therefore, it is possible to reduce the inertial force (inertia) of the rotating unit 1 as compared with the case where the back yoke 2c is provided in the rotating unit 1.

  Further, as compared with the case where the back yoke 2c is attached to the rotating unit 1 with an adhesive or the like, for example, the manufacturing process of the encoder EC can be simplified and the cost can be reduced by reducing the number of man-hours.

  Further, when the back yoke 2c is attached to the rotating portion 1, the back yoke 2c may be peeled off to cause a defect. However, according to the encoder EC of the present embodiment, such a concern can be eliminated and the reliability of the encoder EC can be improved.

Next, a method for attaching the encoder EC to the motor M will be described.
When the encoder EC is attached to the motor M, first, as shown in FIG. 1, the end surface on the flange portion 2b side of the base portion 2 of the encoder EC is opposed to the motor body MB, and the drive shaft MS of the motor M is set to the encoder EC. Is inserted into the insertion hole 1a of the rotating part 1.

Here, as shown in FIG. 1, the encoder EC of the present embodiment attracts the back yoke 2 c of the base portion 2 by the magnetic force of the magnet portion 1 d of the rotating portion 1 and holds the base portion 2 by the rotating portion 1. These can be integrated. Therefore, it can handle integrally in the state which made the rotation part 1 hold | maintain the base part 2. FIG.
As a result, the base part 2 of the encoder EC and the motor body MB can be obtained simply by inserting the drive shaft MS of the motor M into the insertion hole 1a of the rotating part 1 and fitting the key of the drive shaft MS and the key groove of the insertion hole 1a. Are positioned.

Next, the bolt B is disposed in the bolt hole 1b of the rotating unit 1 through the opening 3d provided in the substrate 3c of the detecting unit 3, and the rotating unit 1 and the drive shaft MS of the motor M are fastened by the bolt B.
Next, a not-illustrated bolt is arranged in a not-illustrated bolt hole in the flange portion 2b of the base portion 2, and the base portion 2 and the motor body MB are fastened by a not-illustrated bolt. Here, the attractive force between the magnet portion 1d of the rotating portion 1 and the back yoke 2c of the base portion 2 is smaller than the fastening force of the bolt when the base portion 2 is fixed to the motor main body MB with a bolt. Have been adjusted so that. Therefore, as shown in FIG. 2, the adsorbed state of the rotating part 1 and the base part 2 is released by fastening the base part 2 and the motor body MB with bolts.

  The end surface of the base portion 2 on the motor M side and the motor body MB are in close contact with each other, and a gap G2 is formed between the magnet portion 1d of the rotating portion 1 and the back yoke 2c and back yoke support portion 2d of the base portion 2. The rotating part 1 and the base part 2 are in a separated state. Thereby, the rotating part 1 becomes movable relative to the base part 2 and is in a state of being rotatably accommodated in the accommodating part 2a of the base part 2. Thus, the attachment of the encoder EC to the motor M is completed.

  In the encoder EC and its mounting method of the present embodiment, after fixing the rotating unit 1 to the drive shaft MS of the motor M to be measured in a state where the rotating unit 1 and the base unit 2 are integrated as described above, By fastening the rotating part 1 and the motor body MB with bolts, the rotating part 1 and the base part 2 are separated from each other by using the fastening force of the bolts.

  That is, the process of separating the rotating part 1 and the base part 2 and the process of fixing the base part 2 to the motor body MB can be performed collectively. Therefore, unlike the conventional encoder, the encoder EC is compared with the case where the rotating portion and the base portion are fastened by the screw portion, and the screw portion is loosened when attached to the motor and the base portion and the motor body are fastened. Can be easily installed. Further, the encoder EC can be easily attached as compared with the case where the base portion 2 and the rotating portion 1 are separately arranged at predetermined positions of the motor M.

  It should be noted that the technical scope of the present invention is not limited to the above-described embodiment, and modifications can be made as appropriate without departing from the spirit of the present invention.

1 rotating part, 1d magnet part, 2 base part, 2c back yoke (magnetic member), 3 detecting part, EC encoder, MB motor main body (fixed part), MS drive shaft (measurement object)

Claims (5)

Have a magnet part which magnetic pattern is formed, around a rotation axis, a rotation unit that have a insertion hole which the driving shaft of the driving device is inserted,
A base unit that holds a detection unit that detects a magnetic field of the magnet unit and accommodates the rotation unit;
A magnetic member formed integrally with the base portion at a position facing the magnet portion with respect to the direction of the rotation axis ;
The magnetic member is in close contact with the magnet portion in a state where the rotating portion is not fixed to the drive shaft and the base portion is not fixed to the drive device, and the rotating portion is fixed to the drive shaft, and the base portion The encoder is separated from the magnet portion while being fixed to the driving device . The encoder according to claim 1, wherein
The encoder is characterized in that the rotating part is provided between the detecting part and the magnetic member. The encoder according to claim 1 or 2,
The encoder is characterized in that the magnetic member is a back yoke made of a magnetic material. An encoder mounting method using the encoder according to any one of claims 1 to 3 ,
Fixing the rotating part to the driving device in a state where the magnetic member is attracted to the magnet part and the base part is held by the rotating part;
And a step of separating the rotating portion and the base portion in a state in which the rotating portion is fixed to the driving device . A method for attaching an encoder according to claim 4 ,
The step of separating the rotating part and the base part is performed using a fastening force of a fastening member that fastens the base part and a fixing part to which the base part is fixed. Method.

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