JP5190318B2 - Permanent magnet type laminated iron core and manufacturing method thereof - Google Patents

Description

The present invention relates to a permanent magnet type laminated iron core in which a permanent magnet is inserted into a plurality of magnet mounting holes provided around and a method for manufacturing the same.

In a high output motor, a laminated core provided with a plurality of permanent magnets, for example, a permanent magnet type rotor laminated core (hereinafter also simply referred to as a permanent magnet type laminated core) is arranged inside the stator laminated core. There is something.
In this permanent magnet type laminated iron core, a plurality of magnet mounting holes are formed in a portion corresponding to the magnetic pole, and a permanent magnet is inserted into each magnet mounting hole. In order to prevent the permanent magnet inserted into the magnet mounting hole from rattling or moving in the magnet mounting hole due to the centrifugal force generated when the permanent magnet type laminated iron core rotates or the inertial force during acceleration / deceleration, etc. It was necessary to fix.

As a technique for fixing the permanent magnet in the magnet mounting hole, there are the following methods.
For example, there is a method in which a molten resin is filled in a magnet mounting hole and solidified, and a permanent magnet is fixed to the magnet mounting hole. 6A and 6B, the shaft hole 93 of the laminated iron core 92 in which the permanent magnet 91 is inserted into the magnet mounting hole 90 has a diameter larger than the inner diameter of the shaft hole 93 and a plurality of irregularities. There is a method of press-fitting a rotary shaft 95 formed around 94, deforming the wall of the shaft hole 93 to deform each magnet mounting hole 90, and thereby pressing and fixing the permanent magnet 91 (for example, Patent Documents). 1).

JP 2000-37053 A

However, the conventional method still has the following problems to be solved.
The method using a molten resin is useful because the permanent magnet is reliably fixed in the magnet mounting hole and is useful. However, when the permanent magnet type laminated iron core is used for many years as a motor and then recycled, the magnet mounting hole part Is difficult to disassemble. For this reason, there is a problem that it is difficult to collect a valuable and expensive permanent magnet from a permanent magnet type laminated core. In particular, in recent years, permanent magnets made of rare earth elements have been used to further improve motor efficiency, and it is a big problem that recycling is difficult.

On the other hand, the method of deforming the shaft hole can prevent the permanent magnet from being removed from the magnet mounting hole, and can easily collect the permanent magnet when recycling the permanent magnet type laminated iron core. However, in this method, since the rotating shaft with the irregularities formed on the outer periphery is inserted into the shaft hole of the laminated core, the periphery of the inner surface side of the shaft hole is wrinkled and deformed as a whole. If this is used for many years, fluctuations in rotation transmission and rotation abnormalities such as rotation slip may occur. Furthermore, there is a problem that the accuracy of the roundness of the permanent magnet type laminated iron core may be lowered.

The present invention has been made in view of such circumstances, and the permanent magnet can be easily recovered during recycling, and the permanent magnet inserted into the magnet mounting hole reduces the accuracy of the roundness of the permanent magnet type laminated core. An object of the present invention is to provide a permanent magnet type laminated iron core that can be fixed at a certain position and a method for producing the same.

A permanent magnet type laminated iron core according to the first aspect of the present invention is formed by laminating a plurality of iron core pieces, a plurality of magnets having a shaft hole formed in the center and a plurality of magnets formed in the periphery and inserted with permanent magnets. In the permanent magnet type laminated iron core equipped with a mounting hole, the shaft hole mounted with a rotating shaft,
Notches are formed at intervals in the circumferential direction of the core piece from the shaft hole toward the magnet mounting hole side in a part of the laminated core pieces, and between the adjacent notches. A pressing portion whose base portion protrudes toward the shaft hole side is provided, and the pressing portion is pressed toward the magnet mounting hole side by mounting the rotating shaft in the shaft hole, and the permanent magnet is moved into the magnet mounting hole. It is fixed.

In the permanent magnet type laminated iron core according to the first invention, among the laminated iron core pieces, the iron core pieces on which the notch and the pressing portion are formed are arranged on one side, both sides, or an intermediate portion in the lamination direction. It is preferable that
In the permanent magnet type laminated iron core according to the first aspect of the present invention, the distance between the magnet mounting hole and the notch tip is preferably not less than 1 and not more than 5 times the plate thickness of the iron core piece.

In the permanent magnet type laminated iron core according to the first aspect of the present invention, the notch is formed by a cut formed from the shaft hole toward the magnet mounting hole and a slit formed at the tip side of the cut. It is preferable.
In the permanent magnet type laminated iron core according to the first aspect of the present invention, it is preferable that a stress removing slit for the pressing portion formed to protrude toward the pressing portion is formed on the side portion of the notch.

In the manufacturing method of the permanent magnet type laminated iron core according to the second invention that meets the above-mentioned object, a part of the plurality of iron core pieces is directed to each magnet mounting long hole formed around the central shaft hole piece. A step of forming a notch in the circumferential direction at an interval, and forming a pressing portion whose base protrudes toward the shaft hole piece portion side between the adjacent notches,
A step of caulking and laminating the plurality of iron core pieces to form a laminated core body;
Inserting a permanent magnet into each magnet mounting hole of the laminated core body formed by communicating a long hole for mounting the magnet of the core piece; and
The permanent magnet disposed in each magnet mounting hole by mounting a rotating shaft on the shaft hole of the laminated core body formed by communicating the shaft hole pieces and pressing the pressing portion radially outward. And fixing and holding.

In the permanent magnet type laminated iron core according to the second invention, it is preferable that the rotating shaft is inserted into the shaft hole while being rotated around the axis.

The permanent magnet type laminated core and the manufacturing method thereof according to the present invention are formed by forming notches in the circumferential direction of the core piece from a shaft hole toward each magnet mounting hole side in a part of the laminated core pieces. In addition, since a pressing portion whose base portion protrudes toward the shaft hole side is provided between adjacent notches, the force for pressing the pressing portion toward the magnet mounting hole side when inserting the rotating shaft into the shaft hole is notched. As compared with the case where no is formed, the size can be reduced. Thereby, when inserting a rotating shaft in a shaft hole, each pressing part can be easily pushed out to the magnet mounting hole side of the iron core piece. As a result, the permanent magnet can be obtained without damaging the inner surface side periphery of the shaft hole. Is pressed to the outer peripheral side (radially outward) in each magnet mounting hole, and can be fixed at a fixed position. Therefore, the fixing position of the permanent magnet does not vary, and the weight balance of the permanent magnet type laminated core is improved.
In addition, since a notch is formed in a part of the laminated core pieces and a pressing portion is provided, and since this iron core piece is a pole part in the laminated core body, the perfect magnet type laminated iron core has a perfect circle The accuracy of the shape is excellent, and the shape accuracy is excellent.
Further, since the permanent magnet type laminated iron core does not fix the permanent magnet with resin in the magnet mounting hole, the permanent magnet can be easily recovered from the permanent magnet type laminated iron core, and is suitable for recycling.

Further, when the cutout is formed by a cut formed from the shaft hole toward each magnet mounting hole and a slit formed at the front side of the cut, the obstruction of the flow of magnetic flux due to the cutout can be reduced.
And when forming the stress removal slit of the pressing part which protrudes and is formed on the side part of the notch, the stress in the pressing part based on the pressing force generated when the pressing part is pressed by the rotating shaft Is released and deterioration of iron loss characteristics can be prevented.

Further, when the rotation shaft is inserted into the shaft hole while being rotated about its axis, the rotation shaft can be inserted into the shaft hole without bending the base of the pressing portion. Thereby, fixation of the permanent magnet by the press of a press part can be ensured.

Next, embodiments of the present invention will be described with reference to the accompanying drawings for understanding of the present invention.
Here, FIG. 1 is a perspective view of a permanent magnet type laminated core according to an embodiment of the present invention, FIG. 2 is a plan view of a first core piece constituting the permanent magnet type laminated core, and FIG. The top view of the 2nd core piece which comprises a magnet type lamination iron core, Drawing 4 (A) and (B) are the partial top views of the 2nd core piece concerning the 1st and 2nd modification, respectively, and Drawing 5 It is a top view of the 2nd iron core piece concerning the 3rd modification.

As shown in FIG. 1 to FIG. 3, a permanent magnet type laminated iron core (hereinafter also simply referred to as a laminated iron core) 10 according to an embodiment of the present invention includes a plurality of iron core pieces (a first iron core piece 11, a second iron core piece 2, and a second iron core piece 2). And a plurality of magnet mounting holes 15 which are formed in the periphery and into which permanent magnets 14 are inserted, respectively. A rotating shaft 16 indicated by a two-dot chain line is mounted, and notches 17 and 18 are formed in the iron core piece 12 from the shaft hole 13 toward each magnet mounting hole, and the notches 17 and 18 adjacent to each other are formed. A pressing portion 19 is provided therebetween, and the pressing shaft 19 is pressed toward the magnet mounting hole 15 by mounting the rotating shaft 16 in the shaft hole 13, and the permanent magnet 14 is fixed to the magnet mounting hole 15. This will be described in detail below.

The laminated iron core 10 is configured by punching an electromagnetic steel plate (not shown) having a plate thickness of, for example, about 0.15 to 0.5 mm in a ring shape, and laminating a plurality of punched iron core pieces 11 and 12. is there. In addition, as a lamination | stacking method of the some iron core pieces 11 and 12, although it can use combining any 1 or 2 or more of caulking, welding, and adhesion | attachment, you may just pile up.
As shown in FIG. 1, the laminated core 10 has a plurality (two in this case) of core pieces 12 each having notches 17 and 18 and a pressing portion 19 arranged on both sides in the lamination direction, and the others are notched. And the core piece 11 in which the pressing part is not formed. Here, the both sides in the stacking direction of the laminated core 10 are portions corresponding to the range of 20% or less (preferably 10% or less) of the length of the permanent magnet 14 from the upper and lower ends of the inserted permanent magnet 14, respectively. Means. The core piece 11 and the core piece 12 have the same outer contour shape.

As shown in FIGS. 2 and 3, each iron core piece 11, 12 is formed with shaft hole pieces 20, 21 penetrating in the center, and a plurality of (here, eight) magnets are mounted on the periphery. The long holes 22 and 23 are formed at equal intervals. The shaft hole pieces 20 and 21 of the laminated iron core pieces 11 and 12 communicate with each other to form the shaft hole 13, and the magnet mounting long holes 22 and 23 communicate with each other to form the magnet mounting hole 15.
Further, as shown in FIG. 3, the iron core piece 12 is formed in the inner region of the magnet mounting long hole 23 (in the radial inner region of the iron core piece 12) from the shaft hole piece portion 21 to each magnet mounting long hole 23 side. Two notches 17 and 18 having a distance D in the circumferential direction of the core piece 12 are formed in the direction (that is, from the axial hole 13 of the laminated core 10 toward the magnet mounting holes 15).

Each of the notches 17 and 18 is formed by a slit having a small width. However, as shown in FIG. 4A, the notches 17a and 18a are moved from the shaft hole piece portion 21 to the magnet mounting long holes. You may comprise the cut | interruption 26 formed toward the 23 side, and the slit 27 formed in the front side of a cut | interruption. In addition,
The entire lengths of the notch 17a and the notch 18a are the same length, but may be different lengths. In addition, the slit 27 is formed with a slight width like the notches 17 and 18 described above.
The cut 26 is formed by, for example, cutting and pushing back described in Japanese Patent Application Laid-Open No. 2005-318863, thereby reducing and further preventing a failure in the flow of magnetic flux caused by the formation of the notch. it can. For this reason, the length of the cut line 26 is preferably 50% or more, more preferably 70% or more (upper limit is 90%) of the total length of the notches 17a and 18a.

Each notch 17, 18 is the shortest distance (on the extension line of the notch 17, 18) between the magnet mounting long hole 23 and the tip of the notch 17, 18 (based on the shaft hole piece 21 side). The distance L1 and L2 is preferably 1 to 5 times the plate thickness of the core piece 12 (preferably 1.5 times the lower limit and 3 times the upper limit).
Here, when the shortest distances L1 and L2 are less than 1 times the thickness of the iron core piece, the shortest distances L1 and L2 are too short, and the pressing part is separated from the iron core piece when the pressing part is pressed by the rotating shaft. There is a risk of taking. On the other hand, when the shortest distances L1 and L2 exceed five times the thickness of the iron core piece, the shortest distances L1 and L2 are too long, and a large force is required when pressing the pressing portion with the rotating shaft, and the permanent distance is permanent. The pressing force to the magnet is reduced and the fixing force is weakened.

The distance D between the adjacent notches 17 and 18 is, for example, not less than 0.2 times and not more than 1 time the width of the permanent magnet 14 (preferably, the lower limit is 0.4 times and the upper limit is 0.8 times). It is good to do. Thereby, when pressing a press part with a rotating shaft, positioning of the permanent magnet 14 in the magnet mounting hole 15 can be ensured.
Each of the notches 17 and 18 is formed so that the cut direction is orthogonal to the magnet mounting long hole 23 and the notches 17 and 18 are formed parallel to each other, but inclined with respect to the magnet mounting long hole 23. May be. For example, by forming each notch so that the distance D increases toward the magnet mounting long hole 23 side, the contact portion between the pressing portion formed between adjacent notches and the rotating shaft 16 can be reduced. However, the side surface of the permanent magnet 14 can be pressed in a wide range.

Further, as shown in FIG. 4B, a stress removing slit 29 of the pressing portion 28 formed to protrude toward the pressing portion 28 may be formed on the side portion of the notch 17 on one side.
The stress relief slit 29 is formed in the pressing portion 28 provided between the adjacent notches 17 and 18, even if it is inclined within a range of ± 5 degrees, for example, substantially perpendicular to the pressing direction of the pressing portion 28. It is formed in a good direction (circumferential direction of the core piece). The stress relief slit may be formed in the side portion of the notch 18 on the other side.
The stress removal slit 29 is preferably formed at a base end position within a range of 20% to 80% of the entire length of the notch 17 from the base end (shaft hole piece) side of the notch 17. . The stress relief slit 29 is preferably formed in the range of 0.2 to 0.8 times the distance D between the adjacent notches 17 and 18 with the notch 17 as a base end.
Thereby, the stress in the press part 28 which arises based on the pressing force of the press part 28 is released, and deterioration of an iron loss characteristic can be prevented.

In the present embodiment, the pressing portion 19 provided between the adjacent notch 17 and the notch 18 has a base portion 24 projecting toward the shaft hole piece portion 21 (FIGS. 4A and 4B). The same applies to the modification shown in FIG. The tip portion 25 of the pressing portion 19 is a portion that presses the side surface of the permanent magnet 14.
The protrusion length S1 of the base portion 24 of the pressing portion 19 toward the shaft hole piece portion 21 side with respect to the outer peripheral position of the rotating shaft 16 attached to the shaft hole 13 (the position of the dashed line in FIG. 3) is the permanent magnet 14. For example, 1.2 times to 2 times the gap S2 in the radial direction of the iron core piece 12 formed in the magnet mounting hole 15 (preferably the lower limit is 1.3 times and the upper limit is 1.5). Times). The gap S2 is, for example, 0.05 times to 0.5 times the plate thickness (preferably, the lower limit is 0.1 times and the upper limit is 0.3 times).
The contact-side contour shape of the pressing portion 19 with the rotating shaft 16 is an arc shape along the peripheral surface of the rotating shaft 16, but may be linear.

In addition, the notch and press part formed in an iron core piece can also be made into the structure shown in FIG.
An iron core piece (second iron core piece) 30 shown in FIG. 5 has an axial hole piece portion 31 formed at the center, and a pair of magnet mounting long holes 32 that form a C shape in plan view around the periphery. A plurality of groups 33 (four groups in this case) are arranged at equal intervals.
In the inner region of each magnet mounting long hole 32, 33 formed in the core piece 30 (in the radial direction inner region of the iron core piece 30), the shaft hole piece 31 is directed toward the magnet mounting long holes 32, 33. Two notches 34 and 35 having a gap in the circumferential direction of the iron core piece 30 are formed. In addition, although the distance (distance on the extension line of each notch 34 and 35) from the front-end | tip of each notch 34 and 35 to the long holes 32 and 33 for magnet mounting is the same, it may differ. Here, by making the distances different, when the pressing portions 36 and 37 formed between the adjacent cutouts 34 and 35 are pressed, the deformation method of the magnet mounting long holes 32 and 33 can be adjusted.

As described above, the notches 17 and 18 and the pressing portions 19 are provided on the iron core pieces 12 arranged on both sides in the lamination direction of the permanent magnet type laminated iron core 10, and the laminated core pieces 11 and 12 are laminated. After the permanent magnet 14 is inserted into each magnet mounting hole 15 of the iron core body, the rotating shaft 16 is inserted into the shaft hole 13 so that the rotating shaft 16 comes into contact with the base portion 24 of each pressing portion 19, and the pressing portion 19 is a magnet. Displacement toward the mounting hole 15 side. Thereby, the tip portion 25 of the pressing portion 19 presses the permanent magnet 14 radially outward from the side surface, so that the permanent magnet 14 can be fixed and held in the magnet mounting hole 15.

Then, the manufacturing method of the permanent magnet type | mold laminated iron core which concerns on one embodiment of this invention is demonstrated.
First, by using a die having a die and a punch, annular core pieces 11 and 12 having shaft hole pieces 20 and 21 and magnet mounting long holes 22 and 23 formed from an electromagnetic steel plate (not shown). Each is punched. At this time, by forming the two notches 17 and 18 having a distance D in the circumferential direction of the core piece 12 from the shaft hole piece portion 21 toward the long hole 23 for mounting each magnet on the iron piece 12, The pressing part 19 in which the base part 24 protrudes toward the shaft hole piece part 21 side is formed between the adjacent notches 17 and 18 (the iron core piece forming step).
Then, the plurality of punched core pieces 11 and 12 are caulked so that the core pieces 12 in which the notches 17 and 18 and the pressing portions 19 are formed are arranged on both sides in the stacking direction of the permanent magnet type laminated core 10. Lamination is performed to form a laminated core body (lamination process).

Thus, by laminating the plurality of core pieces 11 and 12, the permanent magnets 14 are inserted into the magnet mounting holes 15 of the laminated core body formed by communicating the magnet mounting long holes 22 and 23, respectively. (Permanent magnet insertion process).
Then, the rotating shaft 16 is inserted into the shaft hole 13 of the laminated core body formed by communicating the shaft hole pieces 20 and 21. At this time, each pressing portion 19 provided in the iron core piece 12 is pressed to the magnet mounting hole 15 side (radially outward) by the rotating shaft 16.
Thereby, since the front part 25 of the pressing part 19 presses the permanent magnet 14 from the side surface, the permanent magnet 14 disposed in each magnet mounting hole 15 can be fixed and held (the permanent magnet mounting step).

Depending on the amount of protrusion of the pressing portion 19 toward the shaft hole 13, the distal end surface of the rotating shaft 16 may come into contact with the surface of the base portion 24 of the pressing portion 19 when the rotating shaft 16 is inserted into the shaft hole 13. There is a risk of bending the base 24 of the pressing portion 19.
In order to prevent this, it is preferable to insert the rotating shaft 16 into the shaft hole 13 while rotating the rotating shaft 16 about its axis. At this time, for example, by rounding or chamfering, for example, at the corner of the base of the pressing portion, that is, the corner on the side that first contacts the rotating shaft 16 that is inserted into the shaft hole 13 while rotating. In addition, the pressing portion can be pressed more smoothly.
When the rotating shaft is not rotated, the base of the pressing portion can be easily slid by using the rotating shaft with the tip portion inclined and tapered, so that the pressing portion moves toward the magnet mounting hole 15. It can be pressed smoothly.
Thus, by attaching the rotating shaft 16 to the shaft hole 13, the permanent magnet type laminated iron core 10 can be manufactured.

As described above, the present invention has been described with reference to the embodiment. However, the present invention is not limited to the configuration described in the above embodiment, and the matters described in the scope of claims. Other embodiments and modifications conceivable within the scope are also included. For example, the case where the permanent magnet type laminated iron core of the present invention and the manufacturing method thereof are configured by combining some or all of the above-described embodiments and modifications are also included in the scope of the right of the present invention.
Moreover, in the said embodiment, although the case where the core piece with which the notch and the press part were formed was arrange | positioned 2 pieces each on the both sides of the lamination direction among the laminated core pieces was demonstrated, the permanent magnet to insert Depending on the length, it may be arranged in the middle part in the laminating direction, or may be arranged on one side (one side) in the laminating direction. Moreover, the number of sheets to be arranged may be one by one.

And in the said embodiment, although the case where the core piece pierced cyclically | annularly was used as a some core piece which comprises a permanent magnet type | mold laminated iron core was demonstrated, several arc-shaped couple | bonded by the connection part was demonstrated. You may comprise a segment iron core piece.
Further, the arrangement position and shape of the magnet mounting long holes constituting the magnet mounting hole, the shape, length and number of notches formed in the iron core piece, and the shape and number of the pressing portion are as described above. It is not limited to.

1 is a perspective view of a permanent magnet type laminated iron core according to an embodiment of the present invention. It is a top view of the 1st iron core piece which comprises the permanent magnet type | mold laminated iron core. It is a top view of the 2nd iron core piece which comprises the permanent magnet type | mold laminated iron core. (A), (B) is a partial top view of the 2nd core piece which concerns on a 1st, 2nd modification, respectively. It is a top view of the 2nd iron core piece concerning the 3rd modification. (A) is a top view of the permanent magnet type laminated iron core which concerns on a prior art example, (B) is a front view of the rotating shaft with which the shaft hole of the permanent magnet type laminated iron core is mounted | worn.

Explanation of symbols

10: Permanent magnet type laminated iron core, 11, 12: Iron core piece, 13: Shaft hole, 14: Permanent magnet, 15: Magnet mounting hole, 16: Rotating shaft, 17, 17a, 18, 18a: Notch, 19: Press Part, 20, 21: axial hole piece part, 22, 23: long hole for magnet mounting, 24: base part, 25: tip part, 26: cut, 27: slit, 28: pressing part, 29: slit for stress removal, 30: Iron core piece, 31: Shaft hole piece part, 32, 33: Magnet mounting long hole, 34, 35: Notch, 36, 37: Pressing part

Claims (7)

A plurality of iron core pieces are laminated, and each has a shaft hole formed in the center and a plurality of magnet mounting holes formed in the periphery into which permanent magnets are inserted. In magnet type laminated iron core,
Notches are formed at intervals in the circumferential direction of the core piece from the shaft hole toward the magnet mounting hole side in a part of the laminated core pieces, and between the adjacent notches. A pressing portion whose base portion protrudes toward the shaft hole side is provided, and the pressing portion is pressed toward the magnet mounting hole side by mounting the rotating shaft in the shaft hole, and the permanent magnet is moved into the magnet mounting hole. Permanent magnet type laminated iron core characterized by being fixed. The permanent magnet type laminated iron core according to claim 1, wherein among the laminated iron core pieces, the iron core pieces on which the notches and the pressing portions are formed are arranged on one side, both sides, or an intermediate portion of the lamination direction. A permanent magnet type laminated iron core characterized by having 3. The permanent magnet type laminated iron core according to claim 1, wherein a distance between the magnet mounting hole and the tip of the notch is 1 to 5 times a thickness of the core piece. A permanent magnet type laminated iron core characterized by being. The permanent magnet type laminated iron core according to any one of claims 1 to 3, wherein the notch is formed at a cut formed from the shaft hole toward each magnet mounting hole, and at a front side of the cut. A permanent magnet type laminated iron core comprising a slit formed. The permanent magnet type laminated iron core according to any one of claims 1 to 4, wherein a stress-removing slit of the pressing portion formed to protrude toward the pressing portion is formed on a side portion of the notch. A permanent magnet type laminated iron core characterized by having A part of a plurality of core pieces is formed with a circumferentially spaced notch from the central axial hole piece part toward each magnet mounting slot, and the adjacent notch A step of forming a pressing portion in which the base portion protrudes toward the shaft hole piece portion side,
A step of caulking and laminating the plurality of iron core pieces to form a laminated core body;
Inserting a permanent magnet into each magnet mounting hole of the laminated core body formed by communicating a long hole for mounting the magnet of the core piece; and
The permanent magnet disposed in each magnet mounting hole by mounting a rotating shaft on the shaft hole of the laminated core body formed by communicating the shaft hole pieces and pressing the pressing portion radially outward. A method for manufacturing a permanent magnet type laminated iron core. 7. The method for manufacturing a permanent magnet type laminated iron core according to claim 6, wherein the rotating shaft is inserted into the shaft hole while being rotated about the axis.

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