JP6906285B2 - Magnetic encoder magnetizing device and magnetizing method - Google Patents

Description

The present invention relates to a magnetizing device and a magnetizing method of a magnetic encoder used for detecting a rotation speed or a rotation angle.

Patent Document 1 discloses a magnetizing device and a magnetizing head of a magnetic encoder. The magnetizing head (magnetizing yoke) of the magnetizing device disclosed herein has a core having a tip surface facing or approaching the magnetizing surface of the magnetized body (magnetic encoder), and a conductive wire. Be prepared. The core has a through hole inside the tip surface that penetrates from one end side to the other end of the tip surface. The conductive wire extends the tip surface of the core from one end side to the other end side, and further extends the through hole from the other end side to the one end side. While supplying an alternating current to the conductive wire, the tip surface of the magnetizing head is relatively rotated or moved in a predetermined direction of the magnetizing surface of the magnetized body to magnetize the magnetizing surface of the magnetized body.

Japanese Patent No. 4846863

In the magnetizing method of Patent Document 1, the magnetic flux generated when a current is passed through the conductive wire causes the magnetic flux to pass through the magnetizing surface of the magnetized body facing the tip surface of the core to be magnetized. Further, multi-pole magnetization becomes possible by generating an alternating current by changing the direction of the current flowing through the conductive wire at predetermined angular intervals. However, the magnetic field strength generated by this method is determined by the strength of the current, the material of the core, and the distance between the core and the magnetized body. Since the magnetic field strength is determined by various factors in this way, it is difficult to obtain a desired sufficient magnetic field strength, and there is a problem in the magnetizing strength on the magnetized body.

In Patent Document 1, as shown in FIG. 15 (FIG. 4 of Patent Document 1), the conductive wire 103 is housed in the groove 102c provided on the tip end surface 102a of the core 102. As shown in the enlarged view of FIG. 15D, both side portions of the conductive wire 103 on the tip surface 102a are convex tip surface portions 102aa protruding from the conductive wire 103. In this way, in the core 102 having convex tip surface portions 102aa on both sides of the conductive wire 103, one pole pair (N pole, S pole) is magnetized by one magnetizing current.

When the magnetized body is an axial type, the magnetized region 105 of the magnetized body 104 is fan-shaped as shown in FIG. 16 (A), whereas the convex tip surface portion 102aa of the core 102 (FIG. 15 (A)). ), (D)) are rectangular. Therefore, when the fan-shaped magnetizing region 15 of the magnetized body 104 is magnetized by the rectangular tip surface portion 102aa of the core 102, the magnetic patterns 106 are magnetized in an overlapping manner as shown in FIG. 16B. There is a problem that the region 107 becomes wide and the magnetic pattern is disturbed.

Further, in Patent Document 1, as shown in FIG. 17 (FIG. 7 of Patent Document 1), one conductive wire 103 extends from one end of the core 102, is bent at the other end side and extends to one end side, and further extends to one end side. However, it is arranged so that it is bent and extended to the other end side. When the conductive wire 103 has this shape, it is assumed that a magnetic flux in a direction that does not pass perpendicularly to the magnetized body is generated. Furthermore, since the tip region of the core 102 facing the magnetized body becomes wider, there is concern about the influence on the already magnetized region when magnetizing while generating an alternating magnetic field, and the accuracy of the magnetizing pitch deteriorates. There is a risk of doing.

An object of the present invention is to provide a magnetizing device and a magnetizing method capable of obtaining a magnetic encoder magnetized with high strength and high accuracy with little influence on an already magnetized region.

The magnetizing device of the magnetic encoder of the present invention is a magnetic encoder in which a magnetic track is formed in which the north and south poles are arranged in a predetermined magnetizing pattern by magnetizing the unmagnetized surface of the magnetized body. Is a magnetizer that obtains
A magnetizing yoke in which a plurality of conductor grooves along the boundary between the north and south poles of the magnetic track are formed on the tip surface of the magnetized body facing the unmagnetized magnetized surface.
When both ends are connected to a magnetizing power supply and a plurality of different fitting portions are fitted into the plurality of conductor grooves and a current is passed through the magnetizing power supply, the plurality of fitting portions of the plurality of fitting portions are mutually connected. A conductor wired so that the current flows in opposite directions at the two adjacent fitting parts,
The magnetized yoke and the magnetized body so that the tip surface of the magnetized yoke and the magnetized surface of the magnetized body move relative to each other in the alignment direction of the north and south poles of the magnetic track. A rotating means that rotates at least one of the
It is characterized by having.

The magnetizing device having this configuration magnetizes the magnetized body as follows. That is, with the tip surface of the magnetized yoke facing the unmagnetized magnetized surface of the magnetized body, the tip surface of the magnetized yoke and the magnetized surface of the magnetized body are N poles in the magnetic track by the rotating means. A magnetizing current is passed through the conductor by the magnetizing power source while rotating at least one of the magnetized body and the magnetizing yoke so as to move relatively along the alignment direction of the S pole and the S pole. As a result, one row of magnetic tracks is magnetized on the unmagnetized magnetized surface. By changing the direction of the magnetizing current flowing through the conductor, the north and south poles are alternately magnetized.

The magnetic flux when a magnetizing current is passed through the conductor flows in a circle around the conductor. In the case of the magnetizing device having this configuration, the directions of the currents flowing in the two fitting portions adjacent to each other among the plurality of fitting portions of the conductors fitted in the plurality of conductor grooves are opposite to each other. , Magnetic fluxes in opposite directions are generated around these two fitting portions. When the magnetic fluxes overlap, it can be considered as a combination of vectors. Therefore, a strong magnetic flux in which the two magnetic fluxes are combined is generated at the central tip surface portion sandwiched between the two fitting portions of the conductor on the tip surface of the magnetizing yoke. On the other hand, in the tip surface portions on both sides of the two fitting portions, the two magnetic fluxes interfere with each other to become a weak magnetic flux.

When the tip surface of the magnetizing yoke faces the unmagnetized magnetized surface of the magnetized body, the magnetized surface of the magnetized body penetrates from the central tip surface portion, and the inner part of the magnetized surface ( Magnetic flux flows through the tip surfaces on both sides via the core metal) to magnetize the magnetized surface. Alternatively, a magnetic flux flows in the opposite direction to the above to magnetize the magnetized surface. The result is that the magnetizing strength of the magnetizing surface of the magnetized body facing the central tip surface portion is strong, and the magnetizing strength of the magnetizing surface of the magnetized body facing the tip surface portions on both sides is relatively weak. It is magnetized one pole at a time with a high magnetic flux density by the central tip surface portion.

Further, since the magnetizing strength of the magnetizing surface of the magnetic encoder facing the tip surface portions on both sides is weak, it is possible to reduce the influence on the already magnetized region when multi-pole magnetizing. Therefore, it is possible to suppress the deterioration of the accuracy of the magnetizing pitch and perform high-precision magnetizing. This is particularly advantageous in the case of magnetizing an axial encoder.

In this magnetizer, in a state where the top surface of the magnetization yaw click to face the magnetized surfaces of said unpolarized of the object to be magnetized body, sandwiched between the two mating narrowing portion in the magnetization yoke center It is preferable that the tip surface portion of the magnetized body is closer to the magnetized surface of the magnetized body than the tip surface portions on both sides sandwiching the two fitting portions .
As a result, the central tip surface portion sandwiched between the two fitting portions of the conductors adjacent to each other on the tip surface of the magnetizing yoke can be brought close to each other, and the magnetizing surface of the magnetized body can be brought close to each other, resulting in high magnetic flux density. Magnetism is possible.

Before SL magnetized yoke, the front end surface extending groove to be substantially perpendicular formed for the conductor, the portion following the deposition electromagnetic source from the end of the inlaid part is fitted to the extension groove Is.
In this case, the entire area of the tip surface of the magnetizing yoke in the length direction of the conductor groove is the magnetizable range. Therefore, it is possible to magnetize the magnetized surface of the magnetized body facing the tip surface of the magnetizing yoke with uniform magnetizing strength and magnetizing accuracy.

The magnetizing method of the magnetic encoder of the present invention is a magnetic encoder in which a magnetic track is formed in which the north and south poles are arranged in a predetermined magnetizing pattern by magnetizing the unmagnetized surface of the magnetized body. Is a magnetizing method to obtain
A magnetizing yoke having a plurality of conductor grooves parallel to each other on the tip surface of the magnetized body facing the unmagnetized magnetizing surface, and a plurality of different magnetizing yokes having both ends connected to a magnetizing power supply. When each of the fitting portions is fitted into the plurality of conductor grooves and a current is passed through the magnetizing power supply, the direction in which the current flows in the two fitting portions adjacent to each other among the plurality of fitting portions is determined. Using a conductor wired so as to be opposite to each other, and a rotating means for rotating at least one of the magnetizing yoke and the magnetized body .
Wherein in a state facing the unpolarized magnetized surface, the distal end surface portion of the central sandwiched between the two inlaid part in the magnetization yoke before Symbol magnetized yoke of the front end surface is the object to be magnetized body is, in a position closer to the attachment magnetized surface of the object to be magnetized body than the tip surface portions of both sides of the part inlaid in the two, and the adhesive magnetized surface of the front end surface and the object to be magnetized body before Symbol magnetized yoke Is relatively moved along the alignment direction of the N pole and the S pole in the magnetic track, and a magnetizing current is passed through the conductor to allow one row of magnetism on the unmagnetized magnetized surface. It is characterized by performing a series of magnetizing operations for magnetizing a track.

According to this magnetizing method, it is possible to obtain a magnetic encoder that is magnetized with high strength and high accuracy with little influence on the already magnetized region by the action shown in the description of the magnetizing device.

In this magnetizing method, after performing the series of magnetizing operations, the same series of magnetizing operations is performed in the direction in which the magnetic tracks are aligned with the tip surface of the magnetizing yoke and the magnetized magnetic tracks. By arranging the magnetizing yokes so that the positions do not overlap, the unmagnetized magnetic tracks are magnetized on the unmagnetized magnetized surface in multiple rows, so that the magnetized body is unmagnetized. It can be magnetized on the magnetic surface with multiple rows of magnetic tracks.

The magnetizing device of the magnetic encoder of the present invention is a magnetic encoder in which a magnetic track is formed in which the north and south poles are arranged in a predetermined magnetizing pattern by magnetizing the unmagnetized surface of the magnetized body. A plurality of conductor grooves along the boundary between the north and south poles of the magnetic track are formed on the tip surface of the magnetized body facing the unmagnetized surface of the magnetized body. When the formed magnetizing yoke and both ends are connected to a magnetizing power supply, and a plurality of different fitting portions are fitted into the plurality of conductor grooves, and a current is passed through the magnetizing power supply, the above-mentioned A conductor wired so that the directions of current flow are opposite to each other in two fitting portions adjacent to each other among the plurality of fitting portions, and the tip surface of the magnetizing yoke and the engagement of the magnetized body. as the magnetized surface is relatively moved in the direction of arrangement of the N and S poles in the magnetic track, Bei example a rotating means for rotating at least one of the magnetizing yoke and the object to be magnetized body, the magnetizing An extension groove is formed in the yoke so as to be substantially perpendicular to the tip surface, and the conductor is fitted in the extension groove from the end portion of the fitting portion to the magnetizing power source . It is possible to obtain a magnetic encoder that is magnetized with high strength and high accuracy with little influence on the already magnetized region.

The magnetizing method of the magnetic encoder of the present invention is a magnetic encoder in which a magnetic track is formed in which the north and south poles are arranged in a predetermined magnetizing pattern by magnetizing the unmagnetized surface of the magnetized body. Is a magnetizing method to obtain
A magnetizing yoke having a plurality of conductor grooves parallel to each other on the tip surface of the magnetized body facing the unmagnetized magnetizing surface, and a plurality of different magnetizing yokes having both ends connected to a magnetizing power supply. When each of the fitting portions is fitted into the plurality of conductor grooves and a current is passed through the magnetizing power supply, the direction in which the current flows in the two fitting portions adjacent to each other among the plurality of fitting portions is determined. Using a conductor wired so as to be opposite to each other, and a rotating means for rotating at least one of the magnetizing yoke and the magnetized body .
Wherein in a state facing the unpolarized magnetized surface, the distal end surface portion of the central sandwiched between the two inlaid part in the magnetization yoke before Symbol magnetized yoke of the front end surface is the object to be magnetized body is, in a position closer to the attachment magnetized surface of the object to be magnetized body than the tip surface portions of both sides of the part inlaid in the two, and the adhesive magnetized surface of the front end surface and the object to be magnetized body before Symbol magnetized yoke Is relatively moved along the alignment direction of the N pole and the S pole in the magnetic track, and a magnetizing current is passed through the conductor to allow one row of magnetism on the unmagnetized magnetized surface. Since a series of magnetizing operations for magnetizing the track are performed, it is possible to obtain a magnetic encoder that is magnetized with high strength and high accuracy with little influence on the already magnetized region.

It is a figure which shows the schematic structure of the magnetizing apparatus of the magnetic encoder which concerns on embodiment of this invention. It is (A) plan view and (B) IIB-IIB sectional view of the magnetized body magnetized by the magnetizing apparatus. It is (A) plan view, (B) IIIB-IIIB sectional view, (C) IIIC arrow view of an example of a magnetizing yoke and a conductor of the magnetizing apparatus. It is an enlarged plan sectional view of a part of the magnetized yoke. It is (A) plan view and (B) VB-VB cross-sectional view which shows the magnetizing yoke and the magnetized body when magnetizing a radial type magnetized body by the magnetizing yoke of FIG. It is a figure which shows the magnetized body which magnetized the magnetizing track. It is a conceptual diagram of the magnetic flux generated when an electric current is passed through a conductor. It is a partially enlarged view of FIG. 5A. It is the figure which imaged the magnetizing state when magnetizing on the magnetizing surface of the radial type magnetized body using the same magnetizing yoke. (A) plan view, (B) XB-XB sectional view, (C) bottom view, and (D) XD arrow view of different examples of the magnetizing yoke and the conductor. FIG. 10A and (B) are cross-sectional views showing a magnetized yoke and a magnetized body when magnetizing a radial type magnetized body with the magnetizing yoke of FIG. 10, and (A) and (B) show different states. It is a figure which shows the other magnetized body which has a magnetic track magnetized in a double row. A plan view showing the magnetized yoke and the magnetized body when magnetizing an axial type magnetized body with the magnetizing yoke of FIG. 10, and a side view showing a part of the magnetized body in cross section. Is. It is a figure which shows the state of the magnetized surface in the process in the process of magnetizing an axial type magnetized body. It is a figure which shows an example of the magnetizing head in the conventional magnetizing apparatus, (A) shows the bottom surface which is the tip surface of a core, (B) is a cross-sectional view of line AA, (C) is B- A cross-sectional view of line B, (D) is an enlarged view of a part of FIG. 15 (B). (A) is a diagram showing the shape of the magnetized region of the axial type magnetized body, and (B) is a diagram showing the magnetic pattern of the magnetized body of the axial type. It is a figure which shows the arrangement pattern of the conductor in another conventional magnetizing apparatus.

[Embodiment 1 of Magnetizing Device]
An embodiment of the present invention will be described with reference to the drawings.
FIG. 1 is a diagram showing an overall configuration of a magnetizing device for a magnetic encoder according to an embodiment of the present invention. In this magnetizing device 1, while rotating the magnetized body 2 which becomes a magnetic encoder after magnetization, a magnetic track 13 in which N poles and S poles are arranged in a predetermined magnetizing pattern is formed on the magnetizing surface. It is an index magnetizing device that magnetizes the magnet.

As shown in FIG. 2, the magnetized body 2 magnetized by the magnetizing device 1 is a radial type, and a magnetic layer 4 is formed around an annular core metal 3. The outer peripheral surface of the magnetic layer 4 becomes the magnetized surface 5. The magnetic layer 4 is formed by vulcanizing and adhering rubber containing magnetic powder to the core metal 3. The magnetic layer 4 is not limited to the rubber type, and may be a plastic type or the like. By magnetizing such a magnetic layer 4, it becomes a magnet. Types of magnets include ferrite magnets, neodymium magnets, bond magnets, and the like.

In FIG. 1, the magnetizing device 1 includes a magnetizing yoke 8 for magnetizing the magnetizing surface 5 (FIG. 2) of the magnetized body 2, a conductor 19 provided on the magnetizing yoke 8, and the conductor. A magnetizing power supply 16 that supplies a magnetizing current to 19, a magnetizing yoke stage 12 that positions the magnetizing yoke 8 in the XYZ direction, a chuck 6 that holds the magnetized body 2 fixedly, and a motor that rotates the chuck 6. 7 and the measuring device 14 for measuring the magnetizing accuracy after magnetizing the magnetizing surface 5 of the magnetized body 2, and the measuring device stage 15 for positioning the measuring device 14 in the XYZ direction, and all of them are controlled. It includes a control device 17.

The magnetizing yoke 8 is made of a magnetic material, and as shown in FIG. 3, includes a square columnar main body 30 and a convex portion 9 protruding from one end of the main body 30 in the longitudinal direction of the main body 30. The convex portion 9 has the same height as the main body portion 30 and has a narrower width. On the tip surface 10 of the convex portion 9, two linear conductor grooves 11A and 11B extending in the vertical direction from the upper end to the lower end of the tip surface 10 are formed in parallel. Therefore, as shown in FIG. 4, the tip surface 10 of the magnetizing yoke 8 formed of the tip surface of the convex portion 9 has three tip surface portions 10a, 10b, which are divided by the two conductor grooves 11A, 11B. It consists of 10c. In this embodiment, the vertical direction of FIGS. 3 (C) and 4 is the magnetic track arrangement direction.

As the conductor 19, an electric wire in which the periphery of a conductive metal wire is coated with an insulating coating, for example, a magnet wire with an insulating coating used for winding a motor or the like is used. When the conductor 19 is the above-mentioned electric wire, a commercially available one can be used. The thickness of the conductor 19 depends on the magnetizing width of one pole, but is, for example, about 0.5 mm to 1 mm.

The width W1 of the conductor grooves 11A and 11B is set to be slightly larger than the diameter of the conductor 19. The depths of the conductor grooves 11A and 11B are set to such that the conductor 19 does not protrude from the tip surface 10, for example, about 1 mm. The width W2 of the tip surface 10 is set to, for example, less than three times the magnetizing width.

The conductor 19 is provided on the magnetizing yoke 8 by fitting a part of the conductor 19 into the conductor grooves 11A and 11B. Specifically, the fitting portion 19a, which is an arbitrary part of the conductor 19, is fitted into either one of the conductor grooves 11A and 11B (for example, the conductor groove 11A), and is downward (or below) from the conductor groove 11A. The portion protruding upward) is bent at a substantially right angle to the side away from the tip surface 10. Then, the bent conductor 19 is folded back toward the tip surface 10 and further bent at a substantially right angle to fit the other part, the fitting portion 19b, into the other conductor groove 11B. The portion of the conductor 19 protruding upward (or downward) from the conductor grooves 11A and 11B is bent at a substantially right angle to the side away from the tip surface 10. Then, the bent end is extended along the upper surface (or lower surface) of the main body 30 of the magnetizing yoke 8, and both ends of the conductor 19 are connected to the magnetizing power supply 16 (FIG. 1).

By providing the conductor 19 on the magnetizing yoke 8 as described above, the conductor 19 has a portion other than the fitting portions 19a and 19b substantially perpendicular to the tip surface 10. Therefore, when the tip surface 10 of the magnetizing yoke 8 faces the magnetizing surface 5 of the magnetized body 2 and a magnetizing current is passed through the conductor 19, it is generated from a portion other than the fitting portions 19a and 19b. Since the magnetic flux is substantially parallel to the magnetizing surface 5 of the magnetized body 2, it does not affect the magnetizing surface 5. That is, only the fitting portions 19a and 19b of the conductor 19 are the magnetizing region portions 20A involved in the magnetizing of the magnetizing surface 5, and the other portions of the conductor 19 are magnetized by the magnetizing surface 5. The non-magnetized region portion 20B is not involved. To be precise, the magnetized region portion 20A is in the range of the height H1 including the height H of the magnetizing yoke 8 and the diameter of the conductor 19 (see FIG. 3C). In FIG. 3, the conductor 19 is not shown in the middle of the non-magnetized region portion 20B.

As shown in FIG. 3B, it is preferable that the surfaces of the conductor grooves 11A and 11B and the tip surface 10 of the magnetizing yoke 8 are covered with the resin layers 24 and 25, respectively. The resin layers 24 and 25 are, for example, a resin coating having a thickness of about 10 μm to 30 μm (for example, a fluororesin coating). When the resin layer 24 is formed in the conductor grooves 11A and 11B, the insulating property of the conductor 19 is improved. Further, when the resin layer 25 having low friction and low wear is formed on the tip surface 10 of the magnetizing yoke 8, in addition to improving the insulating property of the conductor 19, the magnetizing yoke 8 is subjected to the magnetizing operation. Even if the tip surface 10 comes into contact with the magnetizing surface 5 of the magnetized body 2, the magnetizing surface 5 is unlikely to be damaged.

In the examples shown in FIGS. 3 and 4, two conductor grooves 11A and 11B are formed on the tip surface 10 of the magnetizing yoke 8, but three or more (usually even) conductor grooves are formed. It may be formed. In that case as well, when a current is passed through the conductor 19, the current is applied to two fitting portions adjacent to each other among the plurality of fitting portions of the conductor 19 that are fitted into the plurality of conductor grooves. The conductor 19 is wired so that the flow directions are opposite to each other.

In FIG. 1, the magnetizing power supply 16 outputs a magnetizing current composed of alternating currents in which the directions of the currents are alternately switched. The timing at which the magnetizing power supply 16 outputs the magnetizing current is controlled by the control device 17.

The magnetizing yoke stage 12 moves the magnetizing yoke 8 in the horizontal direction (X-axis direction), the vertical direction (Y-axis direction), and the front-rear direction according to the position of the magnetizing surface 5 (FIG. 2) of the magnetized body 2. It is appropriately moved in the direction (Z-axis direction). As a result, the tip surface 10 of the magnetizing yoke 8 is made to face the unmagnetized magnetized surface 5 of the magnetized body 2 in an appropriate positional relationship. Further, when the magnetizing surface 5 of the magnetized body 2 has a width in the vertical direction capable of forming a double-row magnetic track by magnetizing, the magnetizing yoke stage 12 moves the magnetizing yoke 8 in the vertical direction. By moving to, any magnetic track among the double-row unmagnetized magnetic tracks is confronted with the tip surface 10 of the magnetizing yoke 8.

The chuck 6 has, for example, a clamp mechanism (not shown) having a claw-type structure, and grips the object 2 by pressing the claw of the clamp mechanism against the inner peripheral surface of the object 2. The chuck 6 may have a structure other than this.

The motor 7 rotates the chuck 6 that holds the magnetized body 2 fixedly around the center of rotation O, so that the tip surface 10 of the magnetizing yoke 8 and the magnetizing surface 5 of the magnetizing body 2 are brought into contact with the magnetizing surface 5. The north and south poles magnetized in the magnet are moved relatively in the alignment direction, that is, in the circumferential direction. A high-resolution encoder 18 is built in the motor 7, and the control device 17 controls on / off of the current flowing through the conductor 19 of the magnetizing yoke 8 based on the rotation signal of the encoder 18. , The magnetizing surface 5 of the magnetized body 2 is magnetized.

With the chuck 6 and the motor 7, the tip surface 10 of the magnetizing yoke 8 and the magnetizing surface 5 of the magnetized body 2 are magnetized so as to move relatively in the alignment direction of the north and south poles of the magnetic track 13. A rotating means 23 for rotating the adherend magnetic body 2 with respect to the magnetic yoke 8 is configured.

The measuring device 14 is a device that measures the magnetizing accuracy after magnetizing the magnetizing surface 5 of the magnetized body 2. As the measuring device 14, for example, a hole probe is used.

Similar to the magnetizing yoke stage 12, the measuring device stage 15 moves the measuring device 14 in the horizontal direction, the vertical direction, and the front-rear direction according to the position of the magnetized surface 5 (FIG. 2) of the magnetized body 2. Move as appropriate. As a result, the tip of the measuring device 14 is made to face the magnetized surface 5 of the magnetized body 2 after being magnetized in an appropriate positional relationship.

[Magnetization method 1; Magnetization of radial type magnetized body]
A method of magnetizing the magnetizing surface 5 (magnetic layer 4) of the radial type magnetized body 2 by using the magnetizing device 1 will be described.

As shown in FIG. 1, the unmagnetized magnetized body 2 is fixedly held on the chuck 6. Then, the magnetizing yoke 8 is appropriately moved by the magnetizing yoke stage 12, and as shown in FIG. 5, the tip surface 10 of the magnetizing yoke 8 faces the magnetizing surface 5 of the magnetized body 2. At this time, the fitting portions 19a and 19b of the conductor 19 are substantially parallel to the magnetizing surface 5 of the magnetized body 2 and are a straight line between the north and south poles in the magnetic track of the magnetized body 2 after magnetization. The direction is along the boundary line 26 (see FIG. 6). In this state, while the magnetized body 2 is rotated around the center of rotation O by the motor 7, a magnetizing current is passed through the conductor 19 by the magnetizing power supply 16 (FIG. 1), so that the magnetized body 2 is unmagnetized. The magnetizing surface 5 is magnetized.

With the tip surface 10 of the magnetizing yoke 8 facing the magnetizing surface 5 of the magnetized body 2, the rotation center O of the magnetized body 2 is the two conductor grooves 11A and 11B of the magnetizing yoke 8. It is desirable that the position in the alignment direction of the two conductors is located at the center C between the two conductor grooves 11A and 11B. As a result, the central tip surface portion 10b sandwiched between the two fitting portions 19a and 19b of the conductor 19 on the tip surface 10 of the magnetizing yoke 8 and the magnetizing surface 5 of the magnetized body 2 can be brought close to each other. , Magnetization with high magnetic flux density becomes possible.

When the chuck 6 and the magnetized body 2 are rotated by the motor 7, they move relative to each other in the front-rear direction (Z-axis direction) at the confrontation portion between the tip surface 10 of the magnetizing yoke 8 and the magnetizing surface 5 of the magnetized body 2. do. By properly synchronizing the rotation speed of the magnetized body 2 with the timing of the magnetizing current output by the magnetizing power supply 16, as shown in FIG. 6, the magnetizing surface 5 is oriented in the circumferential direction of the north and south poles. Magnetic tracks 13 that are alternately arranged along the line are formed, and the adherend magnetic body 2 becomes a magnetic encoder.

As described above, the magnetizable region of the magnetizing yoke 8 is limited to the height H1 including the height H of the magnetizing yoke 8 (FIG. 3C and the diameter of the conductor 19). Therefore, as shown in FIG. 5, when the height of the magnetic layer 4 of the magnetized body 2 is higher than the height H1 of the magnetizable region of the magnetizing yoke 8, the magnetism is as shown in FIG. Non-magnetized regions 27 are formed on both the upper and lower sides of the magnetic track 13 of the magnetized body 2 that has become an encoder.

FIG. 7 is a conceptual diagram of the magnetic flux generated when an electric current is passed through the conductor 19. The magnetic flux when the current flows through the conductor 19 flows in a circle around the conductor 19. In the case of this magnetizing device 1, since the directions of the currents flowing through the fitting portions 19a and 19b fitted in the conductor grooves 11A and 11B in the conductor 19 are opposite to each other, the respective fitting portions 19a and 19b The magnetic fluxes MFA and MFB in the opposite directions are generated around the center. When the magnetic fluxes overlap, it can be considered as a combination of vectors. Therefore, in the tip surface portion 10b between the conductor grooves 11A and 11B on the tip surface 10 of the magnetizing yoke 8, a strong magnetic flux in which two magnetic fluxes MFA and MFB are combined is generated. In the outer tip surface portions 10a and 10c of the conductor grooves 11A and 11B, the two magnetic fluxes MFA and MFB interfere with each other to form a weak magnetic flux.

As shown in FIGS. 5A and 5B, in a magnetized state in which the tip surface 10 of the magnetizing yoke 8 faces the unmagnetized magnetized surface 5 of the radial type magnetized body 2, FIG. 5 (A). ) Is a partially enlarged view, as shown in FIG. 8, a magnetic flux flows. That is, the magnetic fluxes MFA and MAB generated by the currents flowing through the fitting portions 19a and 19b of the conductor 19 face the tip surface portion 10b from the central tip surface portion 10b between the conductor grooves 11A and 11B. It flows to the tip surface portions 10a and 10c via the portion of the magnetic layer 4, the core metal 3, and the portions of the magnetic layer 4 facing the tip surface portions 10a and 10c on both sides in order. Alternatively, the magnetic fluxes MFA and MFB flow in the opposite direction to the above. As a result, the magnetized surface 5 (magnetized layer 4) is magnetized. By changing the direction of the magnetizing current flowing through the conductor 19, the north and south poles are alternately magnetized.

Since the central tip surface portion 10b generates a strong magnetic flux in which two magnetic fluxes MFA and MFB are combined, the magnetic flux penetrating the portion of the magnetized surface 5 facing the central tip surface portion 10b is strong. On the other hand, since the magnetic flux flowing through the tip surface portions 10a and 10c on both sides is weakened, the magnetic flux penetrating the magnetized surface 5 facing the tip surface portions 10a and 10c is weakened.

FIG. 9 is an image of a magnetized state when the magnetized surface 5 of the radial type magnetized body 2 is magnetized using the magnetized yoke 8. The central magnetizing region 31 on the magnetizing surface 5 can be magnetized with high strength due to the increased magnetic flux. In the magnetized regions 32 and 32 on both sides, a low-strength magnetized surface is generated by the weakened magnetic flux. Further, when multi-pole magnetizing, the influence of the low-strength magnetizing region 32 on the already magnetized region can be reduced, so that the accuracy deterioration of the magnetizing pitch can be suppressed. In other words, it can be considered that magnetism is performed one pole at a time only at the central tip surface portion 10b.

In FIG. 1, when magnetization is completed, the magnetizing yoke stage 12 is driven to retract the magnetizing yoke 8. After that, the stage 15 for the measuring device is driven so that the measuring device 14 faces the magnetic track 13 to perform measurement. When the measurement is completed, the stage 15 for the measuring device is driven to retract the measuring device 14, and then the chuck 6 is opened to remove the magnetized body 2 serving as the magnetic encoder. This completes a series of magnetizing operations.

[Embodiment 2 of Magnetizing Device]
FIG. 10 shows a different example of the magnetizing yoke. The magnetizing yoke 8 has an extension groove extending in a direction substantially perpendicular to the tip surface 10 on the upper surface and the lower surface intersecting the tip surface 10, following the upper and lower ends of the conductor grooves 11A and 11B of the tip surface 10, respectively. 21A, 21B, 22 are formed. The extension grooves 21A and 21B on the upper surface extend in parallel with each other as shown in FIG. 10 (A). As shown in FIG. 10C, the extension groove 22 on the lower surface is composed of two separating portions 22a and 22b parallel to each other in a portion close to the tip surface 10, and is separated from the tip surface 10 by a certain distance. The portion between the separated portions 22a and 22b is removed to form one wide portion.

The conductor 19 is bent in the same manner as in the first embodiment, and the fitting portion 19a is fitted into the conductor groove 11A on the tip surface 20, and the fitting portion 19b is fitted into the conductor groove 11B. The portion of the conductor 19 that becomes the non-magnetized region portion 20B protruding upward from the conductor grooves 11A and 11B is fitted into the extension grooves 21A and 21B on the upper surface, respectively. Further, the portion of the conductor 19 that becomes the non-magnetized region portion 20B protruding downward from the conductor grooves 11A and 11B is fitted into the extension groove 22 on the lower surface.

By fitting the non-magnetizing region portion 20B of the conductor 19 into the extension grooves 21A, 21B, 22 in this way, the entire height H of the tip surface 10 of the magnetizing yoke 8 becomes a magnetizable range. That is, the magnetizable range is the same height as the magnetizing yoke 8. As a result, when the tip surface 10 of the magnetizing yoke 8 faces the magnetizing surface 5 of the radial type magnetized body 2, magnetization is performed on the magnetizing surface 5 with uniform magnetizing strength and magnetizing accuracy. be able to.

[Magnetization method 2; Magnetization of radial type magnetized body]
When forming magnetic tracks in upper and lower double rows on the magnetizing surface 5 of the magnetized body 2, magnetization is performed as follows. That is, in the same series of magnetizing operations as described above, as shown in FIG. 11A, the upper region of the tip surface 10 is confronted with the lower portion (height range L) of the magnetizing surface 5. It is magnetized to form the lower magnetic track 13a. Further, as shown in FIG. 11B, the lower region of the tip surface 10 is magnetized while facing the upper portion (height range L) of the magnetized surface 5, and the upper magnetic track 13b is placed. Form. Note that FIG. 11 shows a state in which magnetism is performed using the magnetizing yoke 8 shown in FIG.

Specifically, the magnetizing yoke stage 12 (FIG. 1) is used to magnetize one of the magnetic tracks 13a with the tip surface 10 of the magnetizing yoke 8 facing each other, and then for the magnetizing yoke. The stage 12 is driven to move the tip surface 10 of the magnetizing yoke 8 to the other magnetic track 13b to face each other, and magnetization is performed. At that time, the tip surface 10 of the magnetized yoke 8 and the unmagnetized magnetism are prevented so that the positions of the magnetic track 13a (13b), which is not the object of magnetization, and the tip surface 10 of the magnetized yoke 8 overlap in the alignment direction of the magnetic tracks. Confront the track 13b (13a).

When the magnetizing of both magnetic tracks 13a and 13b is completed, the magnetizing yoke stage 12 is driven to retract the magnetizing yoke 8, and then the measuring device stage 15 is driven to move the measuring device 14 to one side. The measurement is performed by facing the magnetic track 13a. Similarly, the measuring device stage 15 is driven to move the measuring device 14 to the other magnetic track 13b to perform measurement. When the measurement is completed, the stage 15 for the measuring device is driven to retract the measuring device 14, and then the chuck 6 is released to remove the magnetized body 2 serving as the magnetic encoder. This completes a series of magnetizing operations.

By performing the magnetizing operation as described above, the magnetic encoder shown in FIG. 12 can be obtained. The magnetized body 7 serving as the magnetic encoder has a double-row magnetic track 13 in which two rows of magnetic tracks 13a and 13b are arranged one above the other.

The region magnetized on the magnetizing surface 5 of the radial type magnetized body 2 is the fitting portion 19a, 19b of the conductor 19 fitted in the conductor grooves 11A, 11B of the tip surface 10 of the magnetizing yoke 8. Since the height range is limited to, even when the magnetizing surface 5 is divided into a plurality of rows of magnetic tracks 13a and 13b and magnetized, magnetization that does not affect the respective magnetic tracks 13a and 13b is possible. At this time, as described above, the magnetic tracks 13a and 13b may be magnetized so that the magnetizable ranges H2 of the magnetizing yoke 8 do not overlap.

When the vertical height H2 of the tip surface 10 of the magnetizing yoke 8 and the vertical height L of the designed magnetic tracks 13a and 13b are the same, they are formed on the unmagnetized magnetized surface 5 of the magnetized body 2. The tip surface 10 of the magnetizing yoke 8 is aligned with the position of the magnetic track in the double row to face each other, and then magnetization is performed.

[Magnetization on axial type magnetized body]
FIG. 13 shows a state in which the axial type magnetized body 2 is magnetized using the magnetizing yoke 8 of FIG. In the axial type adherend magnetic body 2, a magnetic layer 4 is formed on one side of a disk-shaped core metal 3. The materials of the core metal 3 and the magnetic layer 4 are the same as described above. The core metal 3 shown in FIG. 13 has a through hole 3a in the central portion, and an annular convex portion 3b is formed on the peripheral edge of the through hole 3a on a surface on which the magnetic layer 4 is not formed. However, the axial type adherend 2 is not limited to this shape.

When magnetizing the axial type magnetized body 2, the tip surface of the magnetized yoke 8 so that the center line C of the central tip surface portion 10b of the magnetized yoke 8 passes through the rotation center O of the magnetized body 2. 10 is made to face the magnetizing surface 5 of the magnetized body 2. In this state, while rotating the magnetized body 2 around the center of rotation O, a current is passed through the conductor 19 to magnetize the magnetized surface 5. By changing the direction of the electric current, the north pole and the south pole are magnetized alternately one by one.

FIG. 14 is a diagram showing the state of the magnetized surface 5 in the process of magnetizing the axial type magnetized body 2. Even if the magnetized body 2 is magnetized while rotating, the magnetized pattern 33 can be magnetized without being crushed so much because the area where the magnetized patterns 33 overlap is small.

If the shape of the tip surface of the magnetizing yoke is made arcuate according to the shape of the magnetizing pattern, the magnetizing yoke or the magnetized body can be magnetized without providing a rotating means for rotating the magnetized body. Can be done. However, in that case, every time the diameter of the magnetized body changes, it is necessary to prepare a magnetizing yoke suitable for the diameter. The magnetizing device 1 of the present invention can magnetize a magnetized body 2 having a different diameter with one type of magnetizing yoke 8. Therefore, it is possible to easily magnetize an object to be magnetized in which magnetic tracks are arranged in a plurality of rows.

In the above embodiment, the magnetizing yoke 8 is fixed and magnetizing is performed while rotating the magnetized body 2 by the rotating means 23. On the contrary, the magnetized yoke 8 is fixed and the magnetizing yoke 8 is rotated. Magnetization may be performed while rotating the magnetizing yoke 8 and the magnetized body 2 while rotating the magnetizing yoke 8.

Further, in the above embodiment, the magnetizing yoke 8 is moved up and down by the magnetizing yoke stage 12, so that the unmagnetized magnetic tracks 13a and 13b to be magnetized face the tip surface 10 of the magnetizing yoke 8. However, the magnetized body 2 may be moved up and down so that the unmagnetized magnetic tracks 13a and 13b to be magnetized face the tip surface 10 of the magnetizing yoke 8.

Although the embodiments for carrying out the present invention have been described above based on the examples, the embodiments disclosed here are examples in all respects and are not limiting. The scope of the present invention is shown by the scope of claims rather than the above description, and it is intended to include all modifications within the meaning and scope equivalent to the scope of claims.

1 ... Magnetizing device 2 ... Magnetized body 5 ... Magnetizing surface 8 ... Magnetizing yoke 10 ... Tip surface 11A ... Conductor groove 11B ... Conductor groove 12 ... Magnetic track 12a ... Lower magnetic track 12b ... Upper side Magnetic track 16 ... Magnetizing power supply 19 ... Conductor 19a ... Fitting portion 19b ... Fitting portion 21A ... Extension groove 21B ... Extension groove 22 ... Extension groove 23 ... Rotating means 26 ... Boundary line O ... Rotation center

Claims (4)

A magnetizing device that magnetizes an unmagnetized magnetized surface of a magnetized body to obtain a magnetic encoder in which a magnetic track in which N poles and S poles are arranged in a predetermined magnetizing pattern is formed.
A magnetizing yoke in which a plurality of conductor grooves along the boundary between the north and south poles of the magnetic track are formed on the tip surface of the magnetized body facing the unmagnetized magnetized surface.
When both ends are connected to a magnetizing power supply and a plurality of different fitting portions are fitted into the plurality of conductor grooves and a current is passed through the magnetizing power supply, the plurality of fitting portions of the plurality of fitting portions are mutually connected. A conductor wired so that the current flows in opposite directions at the two adjacent fitting parts,
The magnetized yoke and the magnetized body so that the tip surface of the magnetized yoke and the magnetized surface of the magnetized body move relative to each other in the alignment direction of the north and south poles of the magnetic track. A rotating means that rotates at least one of the
Bei give a, the magnetization yoke, an extension groove to be substantially perpendicular formed with respect to said tip surface, the conductor, the portions following the deposition electromagnetic source from the end extending groove of the inlaid part A magnetizing device for a magnetic encoder, which is characterized by being fitted in. In magnetizer magnetic encoder according to claim 1, wherein the adhesive in a state where the top surface of the magnetic yaw click to face the magnetized surfaces of said unpolarized of the object to be magnetized body, of the two in the magnetization yoke the distal end surface portion of the sandwiched portion the fitting center, magnetizing apparatus of magnetic encoder in the position closer to the attachment magnetized surface of the object to be magnetized body than the tip surface portions of both sides of the part inlaid in the two .. A magnetizing method for obtaining a magnetic encoder in which a magnetic track in which N poles and S poles are arranged in a predetermined magnetizing pattern is formed by magnetizing an unmagnetized magnetized surface of a magnetized body.
A magnetizing yoke having a plurality of conductor grooves parallel to each other on the tip surface of the magnetized body facing the unmagnetized magnetizing surface, and a plurality of different magnetizing yokes having both ends connected to a magnetizing power supply. When each of the fitting portions is fitted into the plurality of conductor grooves and a current is passed through the magnetizing power supply, the direction in which the current flows in the two fitting portions adjacent to each other among the plurality of fitting portions is determined. Using a conductor wired so as to be opposite to each other, and a rotating means for rotating at least one of the magnetizing yoke and the magnetized body.
The magnetizing yoke is formed with an extension groove substantially perpendicular to the tip surface, and the conductor is fitted into the extension groove from an end portion of the fitting portion to a portion following the magnetizing power supply. Ori,
In a state where the tip surface of the magnetized yoke faces the unmagnetized magnetized surface of the magnetized body, the central tip surface portion sandwiched between the two fitting portions in the magnetized yoke is the said. The tip surface of the magnetized yoke and the magnetized surface of the magnetized body are located closer to the magnetized surface of the magnetized body than the tip surface portions on both sides of the two fitting portions. By passing a magnetizing current through the conductor while relatively moving along the alignment direction of the N pole and the S pole in the magnetic track, one row of the magnetic track is formed on the unmagnetized magnetized surface. A method for magnetizing a magnetic encoder, which comprises performing a series of magnetizing operations for magnetizing. In the magnetizing method of the magnetic encoder according to claim 3 , after performing the series of magnetizing operations, the same series of magnetizing operations is performed on the magnetic track magnetized with the tip surface of the magnetizing yoke. By arranging the magnetizing yokes so that the positions of the magnetic tracks in the alignment direction do not overlap with each other, the magnetic encoders that magnetize the magnetic tracks in a double row on the unmagnetized magnetized surface are magnetized. Magnetic method.

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