JP2016093091A - Magnet embedded rotor, and method and apparatus for manufacturing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a magnet embedded rotor having high overall magnetic flux density.SOLUTION: A magnet embedded rotor 1 includes: a cylindrical rotor core 2 having an axial hole 4 extending in an axial direction X; and a resin magnet 3 that is formed to fill the axial hole 4 by injection molding and that has a pair of axial end faces 5, 6. The resin magnet 3 includes a linear portion 7 that has a linear shape in cross section perpendicular to the axial direction X of the rotor core 2. The linear portion 7 has a first end 71 and a second end 72 located closer to an outer peripheral side of the rotor core 2 than the first end 71. A gate mark 9 is located on the second end 72 of the linear portion 7 on at least one of the axial end faces (for example 5) of the resin magnet 3.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a magnet-embedded rotor, a manufacturing method thereof, and a manufacturing apparatus.

An IPM motor (Interior Permanent Magnet Motor) having a structure in which a permanent magnet is embedded in a rotor is known. As a magnet-embedded rotor used in the IPM motor, a technique using a known resin magnet containing a ferromagnetic powder and a resin binder is known.
For example, in Patent Document 1, a molten resin magnet material is injected into a slit of a cylindrical rotor set in a mold while being magnetically oriented by a permanent magnet in the mold.

  The slit has an arc shape in cross section, and has a pair of end portions close to the outer periphery of the rotor core and a bottom portion disposed radially inward of the rotor core from the pair of end portions. A gate provided in the mold for injecting the resin magnet material is disposed at a position facing the bottom portion in the axial direction of the rotor core.

JP 2002-44915 A

In the resin magnet material injected into the slit, the orientation rate and magnetization rate at the bottom are lower than the orientation rate and magnetization rate at the pair of ends.
Therefore, the resin magnet injected from the gate and solidified in the slit reaches a pair of ends from the bottom and is highly solidified under a high orientation rate and high magnetization rate, and remains low near the bottom. And a low magnetization portion solidified under an orientation rate or a low magnetization rate.

For this reason, the magnetization rate as the whole resin magnet falls, and the magnetic flux density as the whole rotor becomes low. As a result, the amount of effective magnetic flux interlinked with the stator coil of the motor is reduced, which causes a reduction in the output torque of the rotor.
An object of the present invention is to provide a magnet-embedded rotor having a high magnetic flux density as a whole, a manufacturing method and a manufacturing apparatus therefor.

  In order to achieve the object, the invention of claim 1 includes a cylindrical rotor core (2) in which an axial hole (4) is formed, and a pair of axial end faces (in which the axial hole is filled by injection molding). 5 and 6), and the resin magnet is a linear portion (7) whose cross section perpendicular to the axial direction of the rotor core is linear, and the first end portion (71). ) And a second end portion (72) disposed closer to the outer periphery of the rotor core than the first end portion, and is a linear portion that is at least one axial end face of the resin magnet Provided is a magnet-embedded rotor (1) in which a gate mark (9) is arranged at the second end of the magnet.

In addition, although the alphanumeric character in a parenthesis represents the corresponding component etc. in embodiment mentioned later, this does not mean that this invention should be limited to those embodiment as a matter of course. The same applies hereinafter.
According to a second aspect of the present invention, the resin magnet includes a pair of linear portions (7, 7) adjacent to each other in the circumferential direction of the rotor core and a bottom portion connecting the first ends of the pair of linear portions to each other. (8) may be V-shaped, U-shaped, or arc-shaped, and the gate mark may be disposed at each second end of the pair of linear portions.

  The invention of claim 3 is a cylindrical rotor core in which an axial hole is formed, the axial hole including a linear portion (10) in a cross section perpendicular to the axial direction of the rotor core, and the linear portion Is a rotor core having a first end (11) in a cross section perpendicular to the axial direction of the rotor core and a second end (12) disposed closer to the outer periphery of the rotor core than the first end. And a fluid resin magnet material (J) from the gate (G; GP; GQ) facing the second end of the linear portion to the axial hole of the rotor core, And an injection step of injecting while applying an orientation magnetization magnetic field in the radial direction (Y).

  According to a fourth aspect of the present invention, the axial hole connects a pair of linear portions (10, 10) adjacent to each other in the circumferential direction of the rotor core and a first end of each of the pair of linear portions. V-shaped, U-shaped or arc-shaped having a bottom portion (13), and the resin magnet material is axially directed from a gate disposed opposite to each second end of the pair of linear portions. It may be injected into the hole.

  The invention according to claim 5 is a cylindrical rotor core in which an axial hole is formed, wherein the axial hole includes a linear portion in a cross section perpendicular to the axial direction of the rotor core, and the linear portion is the rotor core. A mold including a cavity in which a rotor core having a first end portion and a second end portion disposed on an outer peripheral side of the rotor core with respect to the first end portion in a cross section perpendicular to the axial direction is disposed, The mold includes an orientation / magnetization device that applies an orientation and magnetization magnetic field in the radial direction of the rotor core, an inlet passage (81), and an outlet passage (82) facing the second end of the linear portion. And a gate (G: GP; GQ) for flowing the resin magnet material in a fluid state to the axial hole of the rotor core, and the center (C2) of the outlet passage is more than the center (C1) of the inlet passage. Offset to the outer periphery of the rotor core It provides apparatus for manufacturing a magnet-embedded rotor of the (M).

  The gate may be formed in a tapered shape so that the center of the outlet passage is offset from the center of the inlet passage toward the outer peripheral side of the rotor core.

  According to the magnet-embedded rotor of the first aspect of the present invention, the gate mark is arranged at the second end portion (end portion on the outer peripheral side of the rotor core) of the linear portion on at least one axial end surface of the resin magnet. Has been. The resin magnet portion solidified at the first end portion is strongly magnetized when passing through the position of the axial hole corresponding to the position of the second end portion where the resin magnet material in a fluid state is a region where the magnetic field is strong. In the state where the strong magnetization is maintained, the material moves to the position of the axial hole corresponding to the first end and is solidified. That is, the resin magnet portion solidified at the first end is magnetized with a high magnetization rate equivalent to that of the resin magnet portion solidified at the second end. Thereby, the magnetization rate as the whole resin magnet can be made high, and the magnetic flux density as the whole magnet-embedded rotor can be made high.

According to the invention of claim 2, when molding a V-shaped, U-shaped or arc-shaped resin magnet at the time of manufacture, the injection amount per unit time when the resin magnet material is injected into the axial hole is increased. Thus, the cycle time can be reduced.
According to the method for manufacturing the magnet-embedded rotor of the invention of claim 3, the resin magnet material in a fluid state has a strong magnetic field at the second end portion (end portion on the outer peripheral side of the rotor core) of the linear portion of the axial hole. After being strongly magnetized, it moves to the first end of the linear part and solidifies. Therefore, the resin magnet portion solidified at the first end of the linear portion is magnetized with a high magnetization rate equivalent to that of the resin magnet portion solidified at the second end of the linear portion. Thereby, the magnetization rate as the whole resin magnet can be made high, and the magnetic flux density as the whole magnet-embedded rotor can be made high.

According to the invention of claim 4, when molding a V-shaped, U-shaped or arc-shaped resin magnet, the injection amount per unit time when the resin magnet material is injected into the axial hole is increased, Cycle time can be reduced.
According to the magnet-embedded rotor manufacturing apparatus of the fifth aspect of the invention, the center of the gate outlet passage is offset to the outer peripheral side of the rotor core from the center of the gate inlet passage. For this reason, when the resin magnet material in a fluidized state passes through the exit passage of the gate and is strongly magnetized with a stronger magnetic field, it moves to the first end of the linear portion of the axial hole and solidifies. . Therefore, the resin magnet portion solidified at the first end of the linear portion is magnetized with a high magnetization rate equivalent to that of the resin magnet portion solidified at the second end of the linear portion. Thereby, the magnetization rate as the whole resin magnet manufactured can be made high, and the magnetic flux density as the whole magnet-embedded rotor can be made high.

  According to the invention of claim 6, the center of the gate outlet passage is offset from the center of the gate inlet passage to the outer peripheral side of the rotor core by a simple shape change in which the gate is formed in a tapered shape in cross section. can do.

FIG. 1A is a plan view of a magnet-embedded rotor according to a first embodiment of the present invention, and FIG. 1B is a cross-sectional view taken along the line IB-IB in FIG. It is. In 1st Embodiment, it is an expanded sectional view around a gate mark. In 1st Embodiment, (a) is a top view of a rotor core, (b) is a bottom view of a rotor core. In 1st Embodiment, it is process drawing which shows the state in which the rotor core was set to the metal mold | die. In 1st Embodiment, it is process drawing which shows the state in the middle of the injection process which inject | emits the resin magnet material from a gate. In 1st Embodiment, it is a typical perspective view of an axial hole, and has shown the flow of the resin magnet material inject | emitted from a gate to an axial hole. In 1st Embodiment, it is typical sectional drawing of the principal part of an orientation and magnetization apparatus and a rotor core, and is explanatory drawing which shows the strength of the magnetic field exerted on each part of the axial hole of the rotor core from an orientation and magnetization apparatus. is there. It is sectional drawing of the gate periphery of the manufacturing apparatus of the magnet embedded rotor of 2nd Embodiment of this invention. It is sectional drawing of the gate periphery of the manufacturing apparatus of the magnet embedded rotor of 3rd Embodiment of this invention.

Embodiments of the present invention will be described with reference to the accompanying drawings.
(First embodiment)
A first embodiment in which a magnet-embedded rotor and a manufacturing method thereof according to the present invention are embodied will be described with reference to FIGS.
FIGS. 1A and 1B are a plan view and a cross-sectional view of a magnet-embedded rotor according to a first embodiment of the present invention. FIG. 2 is a bottom view of the magnet embedded rotor. With reference to FIGS. 1A and 1B, a magnet-embedded rotor 1 includes a cylindrical rotor core 2 and a plurality of resin magnets 3 embedded in the rotor core 2. Here, the resin magnet means a material containing a known ferromagnetic powder and a resin binder.

As shown in FIG. 1B, the rotor core 2 is formed by laminating a large number of annular electromagnetic steel plates 20 in the axial direction X.
As shown in FIGS. 1A and 1B, the rotor core 2 includes an outer peripheral surface 2a, an inner peripheral surface 2b, a first axial end surface 21, a second axial end surface 22, a circumferential direction Z, and the like. And a plurality of axial holes 4 extending in the axial direction X and extending through the axial end faces 21 and 22.

Each resin magnet 3 is formed by filling the corresponding axial hole 4 by injection molding. Each resin magnet 3 includes a first axial end face 5 and a second axial end face 6 that face each other in the axial direction X.
As shown in FIG. 1A, each resin magnet 3 includes a pair of linear portions 7 in which a cross section (not shown) perpendicular to the axial direction X of the rotor core 2 forms a linear shape. A pair of linear portions 7 of each resin magnet 3 is adjacent to the circumferential direction Z of the rotor core 2. Each linear portion 7 includes a first end portion 71 and a second end portion 72 disposed on the outer peripheral side of the rotor core 2 with respect to the first end portion 71.

Each resin magnet 3 includes a bottom portion 8 that connects the first end portions 71 of each of the pair of linear portions 7 adjacent to each other in the circumferential direction Z, so that the cross section perpendicular to the axial direction X of the rotor core 2 It is in the shape of a letter, U, or arc.
Gate marks 9 are formed on the second end portions 72 of the pair of linear portions 7 on the first axial end surface 5 of each resin magnet 3. The gate mark 9 is a shear mark separated from the resin of the gate part after injection molding, and has a convex shape as shown in FIG. A gate mark is not provided on the second axial end face 6 of each resin magnet 3.

3A and 3B are a plan view and a bottom view of the rotor core 2 alone, respectively. As shown in FIGS. 3 (a) and 3 (b), the axial hole 4 opens to the first opening 41 that opens at the first axial end face 21 of the rotor core 2 and the second axial end face 22 of the rotor core 2. And a second opening 42 to be provided.
Each axial hole 4 includes a pair of linear portions 10 in which a cross section (not shown) perpendicular to the axial direction of the rotor core 2 forms a linear shape. A pair of linear portions 10 of each axial hole 4 is adjacent to the circumferential direction Z of the rotor core 2. Each linear portion 10 includes a first end portion 11 and a second end portion 12 disposed on the outer peripheral side of the rotor core 2 with respect to the first end portion 11.

Each axial hole 4 includes a bottom portion 13 that connects the first end portions 11 of the pair of linear portions 10 adjacent to each other in the circumferential direction Z, so that in a cross section perpendicular to the axial direction X of the rotor core 2, It is V-shaped, U-shaped or arc-shaped.
Each of the openings 41 and 42 of the axial hole 4 of the rotor core 2 shown in FIGS. 3A and 3B corresponds to the corresponding axial end faces 5 and 6 of the resin magnet 3 shown in FIGS. 1A and 1B. It is blocked by.

Next, a method for manufacturing the magnet-embedded rotor 1 in the first embodiment will be described.
First, as shown in FIG. 4, the rotor core 2 is set in a mold 50 of a magnet-embedded rotor manufacturing apparatus M. The mold 50 includes an upper mold 51 that faces the first axial end face 21 of the rotor core 2, an intermediate mold 52 that surrounds the periphery of the rotor core 2, and a lower mold 53 that faces the second axial end face 22 of the rotor core 2. Prepare.

The mold 50 includes a gate G that is disposed on the upper mold 51 and injects a resin magnet material. The upper mold 51 is provided with a sprue S and a runner R. A molten resin magnet material J (see FIG. 5) is supplied to the gate G through a sprue S and a runner R from an unillustrated injection molding machine.
As shown in FIG. 6, the gate G faces the second ends 12 (ends on the outer peripheral side of the rotor core 2) of the pair of linear portions 10 in the first opening 41 of the axial hole 4. Placed in position.

As shown in FIG. 4, the mold 50 includes an orientation / magnetization device 30 disposed in an intermediate mold 52 that surrounds the outer peripheral surface 2 a of the rotor core 2.
As shown in FIG. 7, the orientation / magnetization device 30 includes a pair of permanent magnets 31 and 32 that are spaced apart from each other in the circumferential direction Z, and an iron core 33 that is disposed between the permanent magnets 31 and 32. , Provided radially outward with respect to each axial hole 4.

The permanent magnets 31 and 32 have opposite polarities with respect to the circumferential direction Z. The iron core 33 is arranged so as to face the corresponding axial hole 4 of the rotor core 2 in the radial direction Y. An orientation magnetic field and a magnetization magnetic field from the orientation / magnetization device 30 via the iron core 33 are applied in the radial direction Y of the rotor core 2.
Further, FIG. 7 schematically shows how the magnetic flux from each permanent magnet 31, 32 is distributed in each part of the axial hole 4. In the axial hole 4, the magnetic flux density at the bottom portion 13 and the first end portion 11 of the pair of linear portions 10 is lower than the magnetic flux density at the second end portion 12 of the pair of linear portions 10.

That is, the second end portion 12 of the pair of linear portions 10 is under a strong magnetic field, and the bottom portion 13 and the first end portion 11 of the pair of linear portions 10 are the second end portions of the pair of linear portions 10. 12 is under a magnetic field weaker than the magnetic field at 12.
After the rotor core 2 is set in the mold 50, as shown in FIG. 5, an injection step of injecting the resin magnet material J from each gate G into the axial hole 4 is performed. That is, from the gate G which opposes the 2nd end part 12 (refer FIG. 6) of a pair of linear part 10 in the 1st opening part 41 of each axial direction hole 4 of the 1st axial direction end surface 21 of the rotor core 2, it is a flow state The resin magnet material J is ejected while applying the orientation magnetic field shown in FIG.

  As shown in FIG. 6, the resin magnet material J injected from each gate G into the axial hole 4 is formed at the second end 12 of the pair of linear portions 10 in the first opening 41 facing each gate G. The position moves to the position on the bottom 13 side (positions B1 to B4) while moving in the axial direction X via the positions A1 and A2. The position B1 is a position corresponding to the bottom 13 in the first opening 41, and the position B4 is a position corresponding to the bottom 13 in the second opening 42. The positions B2 and B3 are intermediate positions between the position B1 and the position B4 with respect to the axial direction X.

In general, the magnetization of the magnet has a characteristic that the residual magnetization corresponding to the magnetization intensity at the strongest magnetic field experienced in the history is maintained. Therefore, the resin magnet portion that moves and solidifies via the strong magnetic field positions A1 and A2 to the weak magnetic field positions B1 to B4 has a high orientation obtained when passing through the strong magnetic field positions A1 and A2. The residual magnetization due to high magnetization is maintained.
According to the magnet-embedded rotor 1 of the present embodiment, as shown in FIG. 1A, the second end of each pair of linear portions 7 on the first axial end face 5 of each resin magnet 3. A gate mark 9 is arranged at the portion 72 (end portion on the outer peripheral side of the rotor core 2). The resin magnet portion solidified at the first end 71 of the linear portion 7 is the position of the axial hole 4 corresponding to the position of the second end 72 where the resin magnet material J in the flow state is a region where the magnetic field is strong. Is moved to the position of the axial hole 4 corresponding to the first end 71 (positions B1 to B4 in FIG. 6) in a state in which the residual magnetization due to the strong magnetization is retained. And then solidified.

That is, the resin magnet portion solidified at the first end portion 71 is magnetized with a high magnetization rate equivalent to that of the resin magnet portion solidified at the second end portion 72. Thereby, the magnetization rate as the whole resin magnet 3 can be made high, and the magnetic flux density as the whole magnet-embedded rotor 1 can be made high.
Further, according to the magnet-embedded rotor 1, each resin magnet 3 is connected to the pair of linear portions 7 adjacent in the circumferential direction and the first ends 71 of the pair of linear portions 7 to each other. For example, it is V-shaped (may be U-shaped or arc-shaped). Further, the gate mark 9 is disposed on the second end portion 72 of the pair of linear portions 7 on the first axial end surface 5.

  Therefore, when molding the V-shaped resin magnet 3 at the time of manufacture, the resin magnet material J is injected from the pair of gates G into each axial hole 4. Therefore, the injection amount per unit time when the resin magnet material J is injected into the axial hole 4 is increased as compared with the case where the injection is performed from only a single gate for each axial hole, and the cycle time is increased. Can be reduced. Thereby, the manufacturing cost of the magnet embedded rotor 1 can be reduced.

  According to the method of manufacturing a magnet-embedded rotor of the present embodiment, as shown in FIG. 6, the resin magnet portion solidified at the first end 11 of the linear portion 10 of the axial hole 4 is a resin in a fluid state. After the magnet material J is strongly magnetized with a strong magnetic field at the second end portion 12 (end portion on the outer peripheral side of the rotor core 2) of the linear portion 10, the position of the first end portion 11 (positions B1 to B1 in FIG. 6). B4) is moved and solidified. Therefore, the resin magnet portion solidified at the first end portion 11 of the linear portion 10 is magnetized with a high magnetization rate equivalent to that of the resin magnet portion solidified at the second end portion 12 of the linear portion 10. Thereby, the magnetization rate as the resin magnet 3 whole can be made high, and the magnetic flux density as the magnet embedded rotor 1 whole can be made high.

Further, according to this manufacturing method, the pair of gates G are opposed to the second ends 12 of the pair of linear portions 10 in the first openings 41 of the respective axial holes 4. That is, the resin magnet material J is injected from the pair of gates G into each axial hole 4. Therefore, compared with the case where the resin magnet material J is injected into the axial hole 4 from only a single gate, the injection amount per unit time when the resin magnet material J is injected into the axial hole 4 is reduced. By increasing the cycle time, the cycle time can be reduced.
(Second Embodiment)
A second embodiment in which the magnet-embedded rotor manufacturing apparatus according to the present invention is embodied will be described with reference to FIG.

  FIG. 8 shows that the shape of the gate GP is improved in the magnet-embedded rotor manufacturing apparatus M of the second embodiment. That is, the gate GP is a pin gate type, for example, and includes an inlet passage 81 and an outlet passage 82. The outlet passage 82 faces the second end portion 12 of the linear portion 10. The center C <b> 2 of the outlet passage 82 is disposed offset from the center C <b> 1 of the inlet passage 81 toward the outer peripheral side of the rotor core 2.

  Specifically, the gate GP is formed in a tapered shape so that the center C2 of the outlet passage 82 is offset to the outer peripheral side of the rotor core 2 relative to the center C1 of the inlet passage 81. In the cross section of the gate GP, the outer peripheral line L1 of the rotor core 2 is parallel to the axial direction X of the rotor core 2, and the outer peripheral line L2 of the inner peripheral side of the rotor core 2 is in relation to the axial direction X of the rotor core 2. It is formed in one taper so that it may incline.

The resin magnet material J in a fluidized state flowing from the inlet passage 81 of the gate GP is supplied from the outlet passage 82 to the axial hole 4 via the second end portion 12 of the linear portion 10 of the axial hole 4 of the rotor core 2. Is done.
In the second embodiment, the center C <b> 2 of the outlet passage 82 is arranged offset from the center C <b> 1 of the inlet passage 81 toward the outer peripheral side of the rotor core 2. For this reason, the flowing resin magnet material J is strongly magnetized with a stronger magnetic field when passing through the outlet passage 82 of the gate GP. In addition, the resin magnet material J in a fluid state that has passed through the outlet passage 82 of the gate GP passes through a portion closer to the orientation / magnetization device 30 when passing through the axial hole 4, that is, a portion where the magnetic field is stronger. Thus, it is strongly magnetized by a stronger magnetic field. Thereafter, the resin magnet material J in a fluid state moves to the first end portion 11 of the linear portion 10 of the axial hole 4 and solidifies.

Therefore, the resin magnet portion solidified at the first end portion 11 of the linear portion 10 is magnetized with a high magnetization rate equivalent to that of the resin magnet portion solidified at the second end portion 12 of the linear portion 10. Thereby, the magnetization rate as the whole resin magnet 3 manufactured can be made high, and the magnetic flux density as the whole magnet-embedded rotor 1 can be made high.
Further, the center C2 of the outlet passage 82 of the gate GP is offset to the outer peripheral side of the rotor core 2 from the center C1 of the inlet passage 81 of the gate GP by a simple shape change in which the gate GP is formed in a tapered shape in cross section. Can be arranged. By forming the gate GP in a tapered cross section, the passage cross-sectional area of the gate GP decreases toward the outlet passage 82 of the gate GP. For this reason, a gate mark can be made small.
(Third embodiment)
A third embodiment in which the magnet-embedded rotor manufacturing apparatus according to the present invention is embodied will be described with reference to FIG.

In the second embodiment, the gate GP is formed in a tapered section, whereas in the third embodiment, the gate GQ is formed in a straight section.
Specifically, in the cross section of the gate GQ, the outer peripheral line L1 of the rotor core 2 and the outer peripheral line L2 of the rotor core 2 are inclined at an equal angle with respect to the axial direction X of the rotor core 2. . Therefore, the passage sectional area of the gate GQ is constant.

The present invention is not limited to the above embodiment. For example, the gate mark 9 may be disposed on at least one of the first axial end face 5 and the second axial end face 6.
In the case where the resin magnet 3 has a pair of linear portions 7 and a bottom portion 8 and has a V shape, a U shape, or an arc shape, the axial end surfaces 5 to 6 where the gate marks 9 are disposed are as follows: It is only necessary that the gate mark 9 be disposed at at least one second end portion 72 of the pair of linear portions 7.

The shape of the resin magnet may be a W shape or a U shape.
Moreover, although not shown in figure, each resin magnet may be formed with the single linear part. In this case, the linear portions of the plurality of resin magnets may be arranged radially so as to extend in the radial direction of the rotor core.
In the second and third embodiments, the gate is a pin gate. However, the present invention is not limited to this, and the gate may be a submarine gate or a disk gate.

Moreover, in the said embodiment, although the rotor core 2 is formed using the electromagnetic steel plate 20, a rotor core may be formed using other soft magnetic materials, such as electromagnetic soft iron, for example.
In addition, the orientation / magnetization device may use a configuration (for example, a coil) that generates pulses as the orientation magnetic field and the magnetization magnetic field.
In addition, the present invention can be variously modified within the scope of the claims.

  DESCRIPTION OF SYMBOLS 1 ... Magnet embedded type rotor, 2 ... Rotor core, 2a ... Outer peripheral surface, 2b ... Inner peripheral surface, 20 ... Electromagnetic steel plate, 21 ... End surface of 1st axial direction (of rotor core), 22 ... 2nd axial direction of (rotor core) End face, 3 ... resin magnet, 4 ... axial hole, 41 ... first opening, 42 ... second opening, 5 ... first axial end face (of resin magnet), 6 ... second axis (of resin magnet) Direction end face, 7 ... linear part (of resin magnet), 71 ... first end part, 72 ... second end part, 8 ... bottom part, 9 ... gate mark, 10 ... linear part (of axial hole), 11 ... 1st end part, 12 ... 2nd end part, 13 ... Bottom part, 30 ... Orientation and magnetizing device, 31, 32 ... Permanent magnet, 33 ... Iron core, 50 ... Mold, 51 ... Upper mold, 52 ... Intermediate mold 53 ... Lower mold, 81 ... Inlet passage, C1 ... Center of (inlet passage), 82 ... Outlet passage, C2 ... Center of (outlet passage), G: GP; GQ ... Gate, J ... Resin Stone material, L1... Contour line (on the outer periphery side of the rotor core in the cross section of the gate), L2... Contour line on the inner periphery side of the rotor core in the cross section of the gate, M. Direction, Y ... radial direction, Z ... circumferential direction

Claims (6)

A cylindrical rotor core formed with an axial hole;
A resin magnet filled in the axial hole by injection molding and including a pair of axial end faces;
The resin magnet is a linear portion in which a cross section perpendicular to the axial direction of the rotor core forms a linear shape, and a first end portion and a second end portion disposed on the outer peripheral side of the rotor core from the first end portion. A linear portion having
A magnet-embedded rotor in which a gate mark is disposed at a second end portion of the linear portion on at least one axial end surface of the resin magnet. 2. The V-shape according to claim 1, wherein the resin magnet has a pair of linear portions adjacent to each other in the circumferential direction of the rotor core, and a bottom portion that connects the first ends of the pair of linear portions to each other. U-shaped or arc-shaped,
The gate mark is a magnet-embedded rotor disposed at a second end of each of a pair of linear portions. A cylindrical rotor core having an axial hole formed therein, wherein the axial hole includes a linear portion in a cross section perpendicular to the axial direction of the rotor core, and the linear portion is a cross section perpendicular to the axial direction of the rotor core. A step of setting a rotor core having a first end and a second end disposed on the outer peripheral side of the rotor core relative to the first end in a mold;
An injection step of injecting the resin magnet material in a fluidized state into the axial hole of the rotor core while applying an orientation magnetization magnetic field in the radial direction of the rotor core from a gate facing the second end of the linear portion; A method of manufacturing a magnet embedded rotor including: The axial hole according to claim 3, wherein the axial hole has a pair of linear portions adjacent to each other in the circumferential direction of the rotor core, and a bottom portion that connects the first ends of the pair of linear portions to each other. , U-shaped or arc-shaped,
The method of manufacturing a magnet-embedded rotor in which the resin magnet material is injected into an axial hole from a gate disposed opposite to each second end of each of a pair of linear portions. A cylindrical rotor core having an axial hole formed therein, wherein the axial hole includes a linear portion in a cross section perpendicular to the axial direction of the rotor core, and the linear portion is a cross section perpendicular to the axial direction of the rotor core. A mold including a cavity in which a rotor core having a first end and a second end disposed closer to the outer periphery of the rotor core than the first end is disposed,
The mold includes an orientation / magnetization device that applies an orientation magnetization magnetic field in a radial direction of the rotor core, an inlet passage, and an outlet passage that faces the second end of the linear portion. A gate for flowing a resin magnet material to the axial hole of the rotor core,
An apparatus for manufacturing a magnet-embedded rotor, wherein the center of the outlet passage is offset to the outer peripheral side of the rotor core from the center of the inlet passage.   6. The apparatus for manufacturing a magnet-embedded rotor according to claim 5, wherein the gate is formed in a tapered section so that the center of the outlet passage is offset from the center of the inlet passage to the outer peripheral side of the rotor core.

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