The magnetizing yoke includes a base; a set of first segmented cores disposed on the base in a circumference, each of first segmented cores having a recess portion open inward in a radial direction corresponding to the circumference; a set of coil cartridges disposed inside the set of first segmented cores in the radial direction; and a set of positioning members positioning the set of coil cartridges relative to the base. Each of the coil cartridge includes: an insulator having a pair of walls facing each other in the radial direction; a coil disposed between the pair of walls; and a second segmented core including a protrusion received in the recess portion. The insulator, the coil, and the second segmented core are integral with each other. The set of positioning members prevent the set of coil cartridges from moving inward in the radial directions respectively. Each of coil cartridges is detachable from an assembly of the base, a first segmented core, and a positioning member.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority to Japanese Patent Application No. 2023-085960, filed on May 25, 2023, the contents of which are incorporated herein by reference in their entirety.

BACKGROUND

The present invention relates to a magnetizing yoke that magnetizes an object to be magnetized.

The Japanese patent application publication No. 2009-072055 A, referred to as Patent Literature 1, describes a segmented stator in which an insulator is formed on a teeth side of a segmented core by using a resin, a pre-formed coil is fitted around a teeth portion, and a resin is molded around the pre-formed coil. A set of segmented stators is arranged annularly in an outer tube and secured by heating to constitute a stator of a motor.

SUMMARY

The apparatus including the stator and the outer tube described above can be used for a magnetizing yoke that magnetizes an object to be magnetized. In the apparatus of Patent Literature 1, in response to a pulse current energizing the coil, a radially inward force is exerted on the coil. In this configuration, the resin alone supports the coil against the force, which may cause the coil to be pushed out inward in the radial direction. This may cause a life span of the apparatus to be shortened. Further, the segmented core is press fitted in the stator, which causes replacement of the entire apparatus in the event of breakdown of the apparatus caused by burst, or other causes.

Certain embodiments of the present disclosure provide a magnetizing yoke with an improved product life span and capability of partial replacement of parts in the event of breakdown.

According to an embodiment of the present disclosure, the magnetizing yoke includes: a base; a set of first segmented cores disposed on the base in a circumference, each of the first segmented core having a recess portion open inward in a radial direction corresponding to the circumference; a set of coil cartridges disposed inside the set of first segmented cores in a radial direction; and a set of positioning members positioning the set of coil cartridges relative to the base. Each of coil cartridges includes: an insulator having a pair of walls facing each other in the radial direction; a coil disposed between the pair of walls; and a second segmented core including a protrusion received in the recess portion. The set of positioning members prevents the set of coil cartridges from moving inward in the radial direction respectively. The each of the coil cartridges is detachable from an assembly of the base, a first segmented core, and a positioning member.

According to the above embodiment, the magnetizing yoke prevents the coil from being pushed out to improve the product life span and allow the apparatus to be partially repaired in an event of breakdown.

DETAILED DESCRIPTION

The embodiment of the present disclosure will be described appropriately with reference to the drawings. In the description below, a circumferential direction and a redial direction indicate directions based on a base, more specifically, based on a set of positioning members, first segmented cores, and coil cartridges, which are annularly arranged on the base. A vertical direction indicates a direction based on a condition in which different members are set on the base that is placed on a floor.

As shown inFIGS.1and2, a magnetizing yoke1according to the embodiment of the present disclosure is an apparatus that magnetizes a magnet, or an object X to be magnetized, placed in a rotor of a motor. More specifically, the magnetizing yoke1is a ferromagnetic material manufacturing apparatus that produces an object (a ferromagnetic material) by magnetizing the object X that is initially being a paramagnetic material. The magnetizing yoke1includes a base2, an object placement member3, multiple sets of positioning members40, first segmented cores50, and coil cartridges4, and a set of circuit parts120.

InFIG.1, members disposed above the positioning members40, the first segmented cores50, the coil cartridges4, and the circuit parts120are omitted. InFIG.2, only a second annular member30of the base2and the positioning members40are obliquely hatched for easily recognizing flow paths of a cooling medium.

The base2is a part on which the first segmented cores50and the coil cartridges4for magnetizing are disposed. The base2, made of a non-magnetic metal such as steel use stainless (SUS), is placed on a floor G. The base2includes: a circular plate10that is circular in a plan view; a first annular member20that is annular in a plan view and disposed concentrically on the circular plate10; a second annular member30that is annular in a plan view and disposed concentrically on the first annular member20; and a plurality of legs F that is disposed under the circular plate10and supports the circular plate10on the floor G.

The first annular member20is detachably attached to the circular plate10with bolts B. The bolts B of the present embodiment are made of a non-magnetic metal such as SUS. The second annular member30is detachably attached to the first annular member20with the bolt B. An inner diameter of the second annular member30is larger than that of the first annular member20. The second annular member30includes a flow path30atherein communicating with an annular flow path40a, which is to be described below.

The object placement member3is a member on which a rotor of a motor, as the object X to be magnetized, is placed. The object placement member3, made of a non-magnetic metal such as SUS, is disposed on the center of the circular plate10. The shape of the object placement member3is appropriately modifiable according to a shape of the object X.

Each positioning member40positions the first segmented cores50and the coil cartridges4on the base2. Each positioning member40, made of a non-magnetic metal such as SUS, rises from the radially inner portion of the first annular member20. The positioning members40(12 parts in this embodiment) are arranged at the equal angular intervals (30 degrees in this embodiment) in a circumferential direction. Each positioning member40includes a pedestal41disposed on the first annular member20and a shaft42rises from the pedestal41.

The pedestal41, which is in substantially a rectangular parallelepiped, is positioned inside the second annular member30in a radial direction. The pedestal41positions the first segmented core50and prevents the corresponding first segmented core50from moving inward in a radial and circumferential directions.

The shaft42is hollow, and cylindrical in this embodiment. The shaft42positions the coil cartridge4and prevents the corresponding coil cartridge4from moving in a radial and circumferential directions.

The pedestal41and the shaft42define a flow path40atherein, and the flow path40acommunicates with an annular flow path30aformed in the second annular member30. The flow path40aallows cooling medium, such as water, to circulate therein.

Each first segmented core50is shaped in a substantially sector (a central angle of about 30 degrees in this embodiment), made of a magnetic metal such as SS4000 and SPC, and composed of vertically stacked iron plates. The first segmented cores50(12cores in this embodiment) are arranged in a circumference direction. Each first segmented core50includes a recess portion51having an opening that faces inwardly in a radial direction. The recess portion51includes upper and lower ends that are open. The lower end of the recess51includes a positioned portion51ahaving a shape corresponding to a shape of the pedestal41of the positioning member40. That is, the radially inner portion of the first segmented core50is disposed on the first annular member20and the radially outer portion of the first segmented core50is disposed on the second annular member30. The lower end of the radially outer portion of the first segmented core50is set higher than the lower end of the radially inner portion thereof.

The coil cartridges4are arranged radially inside the first segmented cores50and cooperates with the first segmented cores50to magnetize the object X. The coil cartridges4(12cartridges in this embodiment) are arranged in a circumferential direction. As shown inFIGS.3to7, each coil cartridge4includes an insulator5, an edgewise coil (coil)80, a second segmented core90, terminals100,100, and a resin member110.

The insulator5, made of a resin, insulates the edgewise coil80from the first segmented core50and the second segmented core90. As shown inFIG.5, the insulator5includes an inner member60(a wall portion) and an outer member70.

The inner member60constitutes a radially inner wall of the insulator5. The inner member60includes a hole portion60awith a shape corresponding to a tube portion72of the outer member70, which is to be described below. The inner member60includes a step portion60bformed on the radially inner surface of the inner member60at a radially inner periphery of the hole portion60a.

The outer member70constitutes a radially outer part of the insulator5. The outer member70includes a wall portion71at the radially outer side, facing the inner member60, and a tube portion72extending radially inward from the wall portion71. The wall portion71and the tube portion72are integral with each other. The wall71defines a hole portion71acommunicating with the tube portion72.

The tube portion72is substantially rectangular in its axis view. The tube portion72has an end (an inner end in a radial direction) contacting with the periphery of the hole portion60a. The end of the tube portion72can be fitted inside the hole portion60a. The end of the tube portion72is fixed on the inner member60with adhesive (not shown). The tube member72includes an outer corner72awith an R shape that corresponds to a shape of an inner corner80aof the edgewise coil80in this embodiment. This structure can avoid a stress concentration on the outer corner72aof the tube portion72and improve a product life span.

As shown inFIG.4, the edgewise coil80is fitted around the tube portion72. As shown inFIG.6, the edgewise coil80is a concentrated winding metal coil and independently set in each coil cartridge4. The edgewise coil80is formed by bending a flat rectangular wire in an edgewise direction. As compared to a round wire, a flat rectangular wire ensures a larger cross-sectional area, which allows larger current to flow. The edgewise coil80has ends81,81, which are inserted in the proximal end of the terminal100, which is to be described below, and fixed by crimping.

The second segmented core90, made of a magnetic metal such as SS4000 and SPC, is composed of vertically stacked iron plates. The second segmented core90cooperates with the first segmented core50and serves as a core of the magnetizing yoke1. As shown inFIG.7, the second segmented core90integrally includes a flanged wall91and a broadly defined convex portion92extending radially outward from the flanged wall91.

The flanged wall91is received in a recess portion, or the step portion60b, of in the inner member60.

The convex portion92includes a teeth portion92athat is a proximal end portion (radially inner portion) and a distal end portion (radially outer portion) that is a narrowly defined convex portion, or a protrusion92b.

The teeth portion92ais a portion of the convex portion92, which is inserted in the edgewise coil80or the tube portion72.

The protrusion92bis a portion of the broadly defined convex portion92, which is received in the recess portion51of the first segmented core50so as to be exposed radially outward from the edgewise coil80or the tube portion72. The protrusion92bincludes a through hole92b1vertically extending therethrough.

As shown inFIG.3, the terminal100, made of metal, electrically connects the edgewise coil80and the circuit part120to each other. The proximal end101of the terminal100has a shape that allows an end81of the edgewise coil80to be inserted into the proximal end101. The terminal100further includes a distal end102that has a shape (like a hole) allowing the bolt B to be inserted into the distal end102.

As shown inFIG.4, the resin member110, made of a thermosetting resin, covers the edgewise coil80between a pair of walls (the inner member60and the wall71) of the insulator5. The resin member110uncured, having a high viscosity (nearly 150 Pa*s), is applied on a desired part and then cures by heat. The resin member110fixes the insulator5, the edgewise coil80, and the terminals100in place and secures insulation between the neighboring edgewise coils80.

The circuit part120is disposed across the neighboring first segmented cores50. The circuit part120is detachably secured to two distal ends102with the bolts B, one is of the terminal100of the coil cartridge4and the other is of the terminal100of the neighboring coil cartridge4. The circuit part120is formed of a resin and a metal and has a part of a circuit to electrically connect the neighboring terminals100to each other, which are connected to the ends81of the edgewise coils80respectively. More specifically, the neighboring circuit parts120are electrically connected to each other with wirings. The circuit part120configures a circuit in cooperation with the edgewise coil80and the wirings to allow a pulse current to flow.

A method of assembling the coil cartridge4will be described below. First, an operator inserts the convex portion92of the second segmented core90into the hole portion60aof the inner member60to receive the flanged wall91of the second segmented core90in the step portion60bof the inner member60. Next, the operator fits the edgewise coil80around the convex portion92. Next, the operator inserts the tube portion72of the outer member70into a space between the convex portion92and the edgewise coil80, and then secures the inner member60and the outer member70to each other with an adhesive. Next, the operator crimps the proximal end101of the terminal100to the end81of the edgewise coil80. Next, the operator applies an uncured thermosetting resin to be cured so as to cover the edgewise coil80and the proximal end101of terminal100, thereby forming the resin member110.

A method of attaching the coil cartridge4to a set of parts including the base2, the positioning member40, and the first segmented core50will be described below. The operator inserts the shaft42of the positioning member40into the through hole92b1formed in the protrusion92bof the coil cartridge4to place the coil cartridge4on the first annular member20of the base2. In this embodiment, the insulator5, the edgewise coil80, and other parts of the coil cartridge4are located inside the first segmented core50in a radial direction and the protrusion92bis disposed in the recess portion51of the first segmented core50. The radially inner surface of the pedestal41of the positioning member40can be covered with the inner member60(the wall portion) of the insulator5or a resin wall member other than the insulator5.

Next, the operator places the circuit part120on the first segmented core50and the protrusion92bof the coil cartridge4and secures the circuit part120to the first segmented core50with the bolts B.

Next, the operator connects and secures the distal ends102of the terminals100of the coil cartridge4to the circuit parts120with the bolts B respectively.

Next, the method of magnetizing the object X using the magnetizing yoke1will be described. First, the operator sets the object X on the object placement member3. Next, the operator manipulates an operation panel (not shown). According to the operation, a controller (not shown) makes a pulse current flow into the edgewise coil80of the coil cartridge4and activates a pump (not shown), thereby circulating the cooling medium through the flow path40aof the positioning member40. With this operation, the first segmented core50, edgewise coil80, and second segmented core90are cooled and a magnetic field in the first segmented core50, the second segmented core90, and the edgewise coil80is generated, thereby magnetizing the object X.

The inner member60(the wall portion) of the insulator5prevents the edgewise coil80from moving in a radially inward direction. In this embodiment, the flanged wall91of the second segmented core90prevents the inner member60of the insulator5from moving in a radially inward direction. Therefore, this structure prevents the edgewise coil80from moving in a radially inward direction under a force generated by the energization.

(Method of Replacing Coil Cartridge in Case of Failure)

When the edgewise coil80and/or the terminal100breakdown or burst caused by a pulse current generation, the operator can remove a broken terminal100of the coil cartridge4from the circuit part120and remove the protrusion92bfrom the shaft42of the positioning member40. This allows for replacement of the coil cartridge4alone having the broken edgewise coil80and/or the terminal100.

According to the embodiment of the present disclosure, the magnetizing yoke1includes: a base2; a set of first segmented cores50disposed on the base2in a circumference, each of first segmented cores50having a recess portion51open inward in a radial direction corresponding to the circumference; a set of coil cartridges4disposed inside the set of first segmented cores50in the radial direction; and a set of positioning members40positioning the set of coil cartridges4relative to the base2. Each of coil cartridges4comprises: an insulator5having a pair of walls facing each other in the radial direction; a coil disposed between the pair of walls; and a second segmented core90having a protrusion92breceived in the recess portion51. The set of positioning members40prevent the set of coil cartridges4from moving inward in radial directions respectively. Each of coil cartridges4is detachable from an assembly of the base2, a first segmented core50, and a positioning member40.

Therefore, the magnetizing yoke1prevents the coil from being pushed out. This improves a product life span and also allows the magnetizing yoke1to be partially repairable in an event of breakdown.

In the magnetizing yoke1, the positioning member40includes a shaft42disposed upward from the base2. The shaft42is inserted in a through hole92b1formed in the protrusion92b.

According to the magnetizing yoke1, the shaft42and the through hole92b1appropriately position the coil cartridge4relative to the base2and the first segmented core50. They appropriately prevent the second segmented core90(or the edgewise coil80) from moving inward in a radial direction.

In the magnetizing yoke1, the hollow shaft42is capable of circulating a cooling medium therethrough.

Therefore, the magnetizing yoke1achieves, with the shaft42, functions of positioning the coil cartridge4, preventing a movement of the coil cartridge4, and cooling the first segmented core50and the coil cartridge4, thereby reducing the number of parts.

In the magnetizing yoke1, the positioning member40includes a pedestal41that defines an end of the shaft42. The pedestal41positions the first segmented core50relative to the base2.

According to the magnetizing yoke1, the positioning member40position the first segmented core50and the coil cartridge4relative to the base2, thereby achieving an appropriate magnetizing property as well as reducing the number of parts.

In the magnetizing yoke1, the insulator5includes a tube portion72that connects the pair of walls together. The coil is fitted around the tube portion72. The second segmented core90includes a teeth portion92athat extends from the protrusion92band is received in the tube portion72.

According to the magnetizing yoke1, the tube portion72insulates the coil from the teeth portion92a, thereby achieving an appropriate magnetizing property.

In the magnetizing yoke1, the second segmented core90includes a flanged wall91which extends from the radially inner end of the teeth portion92a. The pair of walls includes an inner wall and an outer wall positioned radially outside the inner wall. The flanged wall91contacts the radially inner wall of the insulator5. The positioning member40prevents the protrusion92bfrom moving inward in a radial direction.

According to the magnetizing yoke1, the flanged wall91of the second segmented core90appropriately prevents the coil from moving inward in a radial direction.

In the magnetizing yoke1, the tube portion72includes an outer corner having an R-shape.

According to the magnetizing yoke1, reduction of stress concentration improves the product life span. The coil, which has a shape corresponding to a shape of the tube portion72, fitted around the tube portion72, thereby improving a securing performance of the coil.

In the magnetizing yoke1, the coil is an edgewise coil.

According to the magnetizing yoke1, a large cross-sectional area of the coil is ensured and allows for a large current flow, thereby achieving an appropriate magnetizing property.

In the magnetizing yoke1, the coil is covered with a resin between the pair of walls.

According to the magnetizing yoke1, insulation is appropriately secured between the neighboring coils.

The magnetizing yoke1further includes a circuit part120configuring a circuit. The coil cartridge4includes a terminal100attached to an end of the coil. The circuit electrically connects the terminal100of the coil cartridge4to the neighboring terminal100disposed on the neighboring coil cartridge4. The terminal100is detachably attached to the circuit part120with a bolt B.

According to the magnetizing yoke1, facilitation of forming a circuit connecting the coils and exchangeability of the coil cartridge4are compatible.

The embodiment of the present disclosure has been described above, but the present disclosure is not limited to this embodiment, and various modifications and variations are also included within a spirit of the present disclosure. For example, the object X to be magnetized is not limited to a rotor of a motor, and the coil is not limited to the edgewise coil80.