JP4273938B2 - Magnetic encoder alignment apparatus and method - Google Patents

Description

  The present invention relates to an alignment apparatus and method for a magnetic encoder that detects the rotational position of a motor used in, for example, industrial robots, NC machine tools, and the like.

An example of a conventional magnetic encoder is disclosed in Patent Document 1. The main structure is shown in FIG.
In FIG. 7, reference numeral 1 denotes a rotary shaft, which is a rotary shaft such as a servo motor (not shown). Reference numeral 2 denotes a permanent magnet for the encoder, which takes out a signal using the magnetic field detection elements 31 to 34 disposed around and detects the rotational position of the rotary shaft. Although not shown, a yoke made of a soft magnetic material is fixed around the magnetic field detection element.
In the above-mentioned Patent Document 1, the method of aligning the magnetic encoder is not clearly described. However, when the rotary shaft 1 is connected to the motor, the rotary shaft 1 and the magnetic encoder are actually permanently connected. After arbitrarily fixing the magnet 2, the rotating shaft 1 is rotated from the outside, the signals of the magnetic field detection elements 31 to 34 arranged around the permanent magnet 2 are monitored, and the motor to which the rotating shaft 1 is connected The phase difference from the induced voltage signal is measured, and the rotary shaft 1 and the permanent magnet 2 are aligned.

FIG. 8 is a flowchart showing a processing procedure of the alignment method in Patent Document 1. In FIG. 8, first, the encoder permanent magnet 2 and the holder (not shown) are fixed at step 31, and the holder is fixed at an arbitrary position of the rotary shaft 1 at step 2. In step 33, the process of configuring the magnetic encoder together with the magnetic field detection elements 31 to 34 is completed. In step 34, the magnetic field detection elements 31 to 34 of the magnetic encoder are driven to rotate the rotating shaft 1, and then the magnetic field detection signal and the induced voltage of the motor are measured. In step 35, the alignment information (phase difference) detected from the two signals is stored in an alignment information storage device such as a controller. This completes the alignment (step 36). As described above, in the conventional magnetic encoder, the procedure of performing the alignment after the alignment process of the magnetic encoder is completed has been taken.
In addition, although not magnetic, there is a type in which an uneven portion for magnetic pole alignment is provided in advance on the rotating shaft, and a groove portion is provided on the rotor shaft side of the encoder so as to be fitted (for example, patent document) 2).

Republished patent WO99-013296 (FIG. 1) Japanese Unexamined Patent Publication No. 07-170696 (FIG. 1)

However, in the conventional magnetic encoder alignment method disclosed in Patent Document 1, when measuring the induced voltage of the motor, there is equipment for rotating the magnetic encoder being aligned, and the induced voltage In addition, a device for driving and detecting the magnetic field detection element of the magnetic encoder is required, and further, positioning information needs to be stored in a separate storage device, which makes it difficult to perform positioning.
In addition, when an uneven portion for magnetic pole alignment is provided on the rotor shaft side of the rotary shaft or encoder as disclosed in Patent Document 2, it is necessary to process the uneven portion in advance, and it is permanent according to the position of the processed portion. There was also a problem that the alignment process increased, such as the need to attach a magnet. In particular, in the case of a small size and a very small rotating shaft, it is extremely difficult to process the concavo-convex portion, and the application range of the magnetic encoder is narrow.
The present invention has been made in view of such various problems, and an object thereof is to provide an alignment method and apparatus that can simplify the alignment process of a magnetic encoder.

In order to solve the above-described problem, the first configuration of the present invention includes a permanent magnet for an encoder magnetized perpendicularly and in one direction with respect to an axis of a rotating shaft of a motor, and a gap in the permanent magnet for the encoder. A magnetic encoder alignment method for fixing a magnetic encoder having at least two magnetic field detection elements facing each other and attached to a fixed body by aligning the magnetic pole position of the encoder permanent magnet with the magnetic pole position of the motor In the above, the rotation shaft whose alignment position with the magnetic pole position of the motor is specified in advance is constrained to a specific position of the alignment restraining means, and the encoder permanent magnet is rotatably mounted on the rotation shaft, The magnetic field applying means for alignment is brought close to the specific position on the outer peripheral portion of the encoder permanent magnet, and the encoder permanent magnet is rotated by an attraction force of different polarity. Is, after resting the specific position, characterized in that to fix the permanent magnet for the encoder to the rotating shaft.
In this first configuration, the magnetic field applying means is a means for generating a magnetic field, such as a permanent magnet or an exciting coil. Rotate to the position where is working. Since the encoder permanent magnet stops at the position where the maximum attractive force acts, the encoder permanent magnet is fixed to the rotating shaft with the position as a specific position. This simplifies the alignment process of the magnetic encoder.

According to a second configuration of the present invention, there is provided an encoder permanent magnet magnetized perpendicularly and in one direction with respect to the axis of the rotation shaft of the motor, and the encoder permanent magnet opposed to each other via a gap. In a magnetic encoder alignment method for fixing a magnetic encoder including at least two magnetic field detection elements attached to a magnetic pole position of the motor to a magnetic pole position of the encoder permanent magnet, A rotary shaft whose alignment position with the magnetic pole position is specified in advance is constrained to a specific position of the alignment restraining means, and the encoder permanent magnet is rotatably mounted on the rotary shaft, and the encoder permanent magnet At least one soft magnetic body is brought close to the outer peripheral portion of the specific position, the encoder permanent magnet is rotated to the position of the soft magnetic body, and the specific position is After resting, and is characterized in that to fix the permanent magnet for the encoder to the rotating shaft.
In this second configuration, the soft magnetic material is a ferromagnetic material that magnetizes when an external magnetic field acts, but loses magnetization when the external magnetic field is erased. When the magnetic field of the encoder permanent magnet approaches, a magnetic field of a different polarity is induced in the soft magnetic material and attracts the magnetic pole of the encoder permanent magnet. The permanent magnet for the encoder is rotated to the position where the maximum attractive force is exerted by the attractive force. Since the encoder permanent magnet stops at the position where the maximum attractive force acts, the encoder permanent magnet is fixed to the rotating shaft with the position as a specific position. This simplifies the alignment process of the magnetic encoder.

According to a third configuration of the present invention, an encoder permanent magnet magnetized perpendicularly and in one direction with respect to the axis of the rotation shaft of the motor, and the encoder permanent magnet are opposed to each other through a gap and attached to a fixed body. In a magnetic encoder alignment apparatus for fixing a magnetic encoder provided with at least two magnetic field detection elements aligned with a magnetic pole position of the motor to a magnetic pole position of the encoder, the magnetic pole position of the motor Is provided with a restraining means for restraining a rotation axis specified in advance at a specific position, and an alignment means provided at an outer peripheral portion of the specific position of the permanent magnet for encoder.
In this third configuration, the rotational axis is constrained to a specific position by the restraining means, the position of the encoder permanent magnet is aligned by the positioning means, and then the encoder permanent magnet and the rotational shaft are fixed, The position of the encoder permanent magnet and the magnetic pole position of the motor are matched. This simplifies the alignment process of the magnetic encoder.

  As the positioning means, at least one permanent magnet magnetized with two poles, at least one excitation coil, or at least one soft magnetic material is used for the encoder. Automatic positioning with the permanent magnet can be performed, and the alignment process of the magnetic encoder can be simplified.

According to the first and second configurations of the present invention, the magnetic field applying means or the soft magnetic material is used for positioning the encoder permanent magnet with respect to the rotating shaft, thereby easily and automatically positioning. This can be performed, and the process of aligning the magnetic encoder can be simplified.
According to the third configuration of the present invention, by providing the restraining means and the positioning means, the position of the encoder permanent magnet and the magnetic pole position of the motor can be automatically matched, The alignment process of the magnetic encoder is simplified.
By using a dipole magnetized permanent magnet as the alignment means, alignment can be easily performed with an inexpensive member. Further, by using the exciting coil as the alignment means, the alignment can be easily performed without moving the magnetic field generating means at the time of alignment. Further, by using a soft magnetic material as the alignment means, alignment can be easily performed with an inexpensive member.

Hereinafter, embodiments of the present invention will be described with reference to FIGS.
(First embodiment)
FIG. 1 is a plan view including a magnetic encoder and alignment components according to the first embodiment of the present invention.
In the figure, the magnetic encoder has a rotating shaft 1, a holder 4 provided around a hole 4 a for fitting the rotating shaft 1, and a permanent magnet 2 for encoder fixed to the holder 4. ing. An alignment permanent magnet 51 as the alignment means 5 is fixed to the base 6 and arranged around the encoder permanent magnet 2.
The rotating shaft 1 is loosely fixed to the base 6 so that it can be attached and detached without causing rotation and in consideration of the magnetic poles of the positioning permanent magnet 51 in the direction in which the rotating shaft 1 and the encoder permanent magnet 2 are aligned. Has been.

  The encoder permanent magnet 2 rotates about the rotary shaft 1 by the attractive force between the polarities of the magnetic pole of the alignment permanent magnet 51 fixed to the base 6 and the magnetic pole of the encoder permanent magnet 2. . Since the maximum attractive force acts at the position where the two magnetic poles face each other, the encoder permanent magnet stops at that position. Thus, the alignment is completed, and the holder 4 and the rotary shaft 1 are fixed, whereby the encoder permanent magnet 2 and the rotary shaft 1 can be aligned. The holder 4 and the rotating shaft 1 can be fixed using screws or an adhesive.

FIG. 2 is a flowchart showing a processing procedure for positioning in the magnetic encoder. Hereinafter, the method of the present invention will be described step by step with reference to this figure.
The motor part having the rotary shaft 1 has been manufactured in advance, and the magnetic pole position is matched with the magnetic field direction of the permanent magnet 51 for alignment, and the parts for the magnetic encoder have been processed. It is assumed that
First, in step 1, the encoder permanent magnet 2 is fixed to the holder 4, and in step 2, the magnetic pole position of the rotary shaft 1 is adjusted to a specific position in the rotation direction of the base 6. In step 3, the holder 4 is inserted into the rotating shaft 1. When the alignment permanent magnet 51 is disposed at a predetermined position of the base 6 in step 4, the encoder permanent magnet 2 rotates together with the holder 4 along the magnetic field direction by the generated magnetic field. Since alignment is performed at this time, the holder 4 and the rotating shaft 1 are fixed as step 5. This completes the alignment (step 6).

  In this embodiment, one alignment permanent magnet 51 is used as a magnetic field generating means for alignment. However, another permanent magnet is disposed at a position facing the rotation shaft 1 as a center. Also good. Further, it is obvious that the same effect can be obtained by arranging a soft magnetic material instead of arranging another permanent magnet. Further, although the encoder permanent magnet 2 is fixed to the rotary shaft 1 via the holder 4, it is obvious that the same effect can be obtained without the holder 4.

(Second Embodiment)
Next, a second embodiment will be described.
FIG. 3 is a plan view including a magnetic encoder and positioning parts according to the second embodiment of the present invention. This embodiment is the same as the first embodiment except that the exciting coil 52 is used as the alignment means 5, and thus the description of the same components is omitted.
FIG. 4 is a flowchart showing a processing procedure for performing alignment of the magnetic encoder according to the second embodiment.

In FIG. 4, the encoder permanent magnet 2 and the holder 4 are first fixed in step 11, and the magnetic pole position of the rotary shaft 1 is adjusted to a specific position in the rotation direction on the base 6 in step 12. In step 13, the holder 4 is inserted into the rotary shaft 1. In step 14, when the electromagnetic coil 52 for alignment is energized, the encoder permanent magnet 2 rotates together with the holder 4 along the magnetic field direction by the generated magnetic field. Since alignment is performed at this time, the holder 4 and the rotating shaft 1 are fixed as step 15. This completes the alignment (step 16).
In this embodiment, one excitation coil 52 is used as a magnetic field generating means for alignment. However, another excitation coil may be arranged at a position facing the rotation shaft 1 as a center. Needless to say, a magnetic path may be provided with a soft magnetic material to induce the magnetic field of the exciting coil. Further, it is self-evident that the same effect can be obtained by arranging a soft magnetic material instead of arranging another exciting coil. Further, although the encoder permanent magnet 2 is fixed to the rotary shaft 1 via the holder 4, it is obvious that the same effect can be obtained without the holder 4.

(Third embodiment)
Next, a third embodiment will be described.
FIG. 5 is a plan view including a magnetic encoder and positioning parts according to the third embodiment of the present invention. This embodiment is the same as the first embodiment except that the soft magnetic body 53 is used as the alignment means 5, and thus the description of the same components is omitted.
FIG. 6 is a flowchart showing a processing procedure for performing alignment of the magnetic encoder according to the third embodiment.

  In FIG. 6, the encoder permanent magnet 2 and the holder 4 are first fixed in step 21, and in step 22, the magnetic pole position of the rotary shaft 1 is adjusted to a specific position in the rotation direction on the base 6. In step 23, the holder 4 is inserted into the rotary shaft 1. In step 24, when the alignment soft magnetic body 53 is disposed at a predetermined position of the base 6, the encoder permanent magnet 2 is made of the soft magnetic body 53 having a small magnetic resistance by the magnetic field generated by the encoder permanent magnet 2. The holder 4 is rotated along the arranged direction. Since alignment is performed at this time, the holder 4 and the rotating shaft 1 are fixed as step 25. This completes the alignment (step 26). In the present embodiment, the magnetic pole of the encoder permanent magnet 2 cannot be determined, so the polarity of the encoder magnet 2 is roughly adjusted to a specific position in the rotational direction (for example, within ± 60 degrees).

  In the description of the present embodiment, one soft magnetic body 53 for alignment is used, but another soft magnetic body or permanent magnet is disposed at a position facing the rotation shaft 1 as a center. Also good. It is obvious that the same effect can be obtained even if the magnetic resistance is reduced by coupling the magnetic paths of two soft magnetic materials. Further, although the encoder permanent magnet 2 is fixed to the rotary shaft 1 via the holder 4, it is obvious that the same effect can be obtained without the holder 4.

  The present invention can be applied to the fields of industrial robots, NC machine tools, and the like as a motor including a magnetic encoder that simplifies the alignment process.

It is a top view which shows the structure of the magnetic encoder main components and the alignment member which show the alignment apparatus of the 1st Embodiment of this invention. It is a flowchart which shows the process sequence of 1st Embodiment. It is a top view which shows the structure of the magnetic encoder main components and the alignment member which show the alignment apparatus of the 2nd Embodiment of this invention. It is a flowchart which shows the process sequence of 2nd Embodiment. It is a top view which shows the structure of the magnetic encoder main components and the alignment member which show the alignment apparatus of 3rd Embodiment in the apparatus of this invention. It is a flowchart which shows the process sequence of 3rd Embodiment. It is a perspective view which shows the structure of the conventional magnetic encoder. It is a flowchart which shows the process sequence of the conventional method.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Rotating shaft 2 Encoder permanent magnet 4 Holder 5 Positioning means 51 Permanent magnet 52 Excitation coil 53 Soft magnetic body 6 Base

Claims (6)

An encoder permanent magnet magnetized perpendicularly and in one direction with respect to the axis of the rotation shaft of the motor, and at least two magnetic field detection elements attached to the fixed body, facing the encoder permanent magnet via a gap. In a magnetic encoder alignment method for fixing a magnetic encoder with a magnetic pole position of the encoder to match a magnetic pole position of the encoder permanent magnet,
Restraining the rotation axis whose alignment position with the magnetic pole position of the motor is specified in advance to a specific position of the alignment restraining means,
The encoder permanent magnet is rotatably mounted on the rotating shaft,
The magnetic field applying means for alignment is brought close to the specific position of the outer peripheral portion of the encoder permanent magnet, and the encoder permanent magnet is rotated by an attractive force of different polarity,
A method for aligning a magnetic encoder, comprising: fixing the permanent magnet for the encoder to the rotating shaft after stopping at the specific position. An encoder permanent magnet magnetized perpendicularly and in one direction with respect to the axis of the rotation shaft of the motor, and at least two magnetic field detection elements attached to the fixed body, facing the encoder permanent magnet via a gap. In a magnetic encoder alignment method for fixing a magnetic encoder with a magnetic pole position of the encoder to match a magnetic pole position of the encoder permanent magnet,
Restraining the rotation axis whose alignment position with the magnetic pole position of the motor is specified in advance to a specific position of the alignment restraining means,
The encoder permanent magnet is rotatably mounted on the rotating shaft,
At least one soft magnetic body is brought close to the outer peripheral portion of the specific position of the encoder permanent magnet, and the encoder permanent magnet is rotated to the position of the soft magnetic body,
A method of aligning a magnetic encoder, comprising: fixing the permanent magnet for the encoder to the rotating shaft after stopping at the specific position. An encoder permanent magnet magnetized perpendicularly and in one direction with respect to the axis of the rotation shaft of the motor, and at least two magnetic field detection elements attached to the fixed body, facing the encoder permanent magnet via a gap. In a magnetic encoder alignment apparatus for fixing a magnetic encoder with a magnetic pole position of the encoder and a magnetic pole position of the encoder permanent magnet,
Constraint means for constraining the rotation axis whose magnetic pole position of the motor is specified in advance to a specific position;
An alignment device for a magnetic encoder, comprising: alignment means provided on an outer peripheral portion of the specific position of the encoder permanent magnet.   4. The magnetic encoder alignment device according to claim 3, wherein the alignment means includes at least one permanent magnet with two poles.   4. The magnetic encoder alignment apparatus according to claim 3, wherein the alignment means includes at least one exciting coil. 4. The magnetic encoder alignment device according to claim 3, wherein the alignment means includes at least one soft magnetic material.

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