JP7415655B2 - How to position the laminated core - Google Patents

Description

The present invention relates to a method for positioning a laminated core.

The rotor of a magnet-embedded motor is composed of a plurality of laminated steel plates, and includes a rotor core having a center hole and a magnet housing hole, and a rotor core that is housed in each magnet housing hole and connected to the rotor core through a thermosetting resin. Equipped with a fixed magnet.

In manufacturing such a rotor, the magnets are fixed to the rotor core by resin molding, that is, by filling the magnet housing holes with resin and thermosetting the resin.

Patent Document 1 discloses a rotor core holding jig (hereinafter referred to as a holding jig) that improves the stacking accuracy of rotor cores by positioning each steel plate during resin molding. The holding jig has a cylindrical portion that fits into the center hole of the rotor core, and a fitting key that fits into a key formed on the inner peripheral surface of the center hole. A portion of the fitting key is made of resin having a higher coefficient of thermal expansion than the steel plate.

During resin molding, the holding jig is heated and the resin portion of the fitting key expands more thermally than other portions, so the fitting key restrains the key of the rotor core. This improves the lamination accuracy of the rotor core by positioning each steel plate. On the other hand, after resin molding, the resin portion shrinks more than other portions due to heat, so the fitting key releases the key of the rotor core.

JP2007-202242A

By the way, in the above-mentioned holding jig, when separating the rotor core and the holding jig after resin molding, it is necessary to wait until the fitting key releases the key of the rotor core, that is, until the temperature of the fitting key decreases. . For this reason, positioning of a laminated core such as a rotor core requires time and effort.

An object of the present invention is to provide a method for positioning a laminated core that allows easy positioning.

A method for positioning a laminated core to achieve the above object is a method for positioning a laminated core that is configured by laminating a plurality of steel plates and positions each of the steel plates in a laminated core having a center hole, the method comprising: After the jig is loosely fitted into the hole, the jig and the laminated core are relatively rotated about the central axis of the center hole, so that the inner peripheral surface of the center hole and the laminated core are aligned in the radial direction of the laminated core. Each of the steel plates is positioned in the radial direction by contacting the outer peripheral surface of the jig.

According to this method, each steel plate is positioned in the radial direction by relatively rotating a jig loosely fitted into a center hole and a laminated core. Since the jig is loosely fitted into the center hole, the jig can be easily attached to and detached from the laminated core. Further, the positioning of each steel plate in the radial direction is performed by a simple method of relatively rotating the jig and the laminated core. Therefore, the laminated core can be easily positioned.

FIG. 2 is a perspective view showing a rotor in one embodiment. FIG. 3 is a vertical cross-sectional view showing the rotor. FIG. 3 is a longitudinal sectional view showing a rotor core with an insertion portion inserted therein. FIG. 3 is a cross-sectional view showing the rotor core with the insertion portion in the insertion position. FIG. 5 is an enlarged cross-sectional view showing part A in FIG. 4 in an enlarged manner. FIG. 3 is an enlarged cross-sectional view showing the rotor core with the insertion portion in the restricted position. FIG. 3 is a longitudinal cross-sectional view showing the rotor core with magnets housed in magnet housing holes. FIG. 3 is a longitudinal cross-sectional view showing a rotor core with magnet housing holes filled with resin. FIG. 7 is an enlarged cross-sectional view showing the rotor core in a state where the insertion portion of the first modification is in the insertion position. FIG. 7 is an enlarged cross-sectional view showing the rotor core in a state where the insertion portion of the first modification is in the regulation position. FIG. 7 is a cross-sectional view showing the rotor core in a state where the insertion portion of the second modification is inserted into the center hole.

Hereinafter, with reference to FIGS. 1 to 8, an embodiment in which a method for positioning a laminated core is embodied as a method for positioning a rotor core of a rotating electric machine will be described.
First, the rotor 10 of the rotating electric machine will be explained.

As shown in FIGS. 1 and 2, the rotor 10 includes a cylindrical rotor core 20 having a center hole 22. As shown in FIGS. A shaft (not shown) is inserted through the center hole 22 . The rotor core 20 is constructed by laminating a plurality of steel plates 21. The steel plate 21 is formed, for example, by punching a silicon steel plate.

Hereinafter, the direction in which the central axis C of the central hole 22 extends will be referred to as the axial direction. Further, the circumferential direction of the rotor core 20 centered on the central axis C is simply referred to as the circumferential direction, and the radial direction of the rotor core 20 centered on the central axis C is simply referred to as the radial direction. Further, in FIG. 1, the clockwise side will be referred to as one side in the circumferential direction, and the counterclockwise side will be referred to as the other side in the circumferential direction. Note that the stacking direction of the steel plates 21 coincides with the axial direction.

As shown in FIG. 1, most of the center hole 22 has a circular shape located on a virtual circle centered on the center axis C. As shown in FIG.
A pair of key portions 23 protruding radially inward are provided on the inner circumferential surface 22a of the center hole 22 over the entire axial direction. The pair of key portions 23 are provided facing each other in the radial direction. The key portion 23 has a substantially square cross-sectional shape perpendicular to the axial direction. The tip of the key portion 23 is located inside the virtual circle in the radial direction.

In the inner circumferential surface 22a of the center hole 22, on both sides of each key portion 23 in the circumferential direction, recessed portions 24 recessed toward the outside in the radial direction are provided over the entire axial direction.
A plurality of magnet housing holes 25 are provided in a portion of the rotor core 20 on the outer peripheral side of the center hole 22 at intervals in the circumferential direction. More specifically, the rotor core 20 is provided with eight pairs of magnet housing holes 25 that are adjacent to each other in the circumferential direction. The cross-sectional shape of the magnet housing hole 25 perpendicular to the axial direction is elongated. The pair of magnet housing holes 25 are located on the inner side in the radial direction as they approach each other.

As shown in FIG. 2, each magnet housing hole 25 accommodates a plate-shaped magnet 30 extending along the axial direction. The inside of each magnet housing hole 25 is filled with resin 31 for fixing the magnet 30. In this embodiment, the steel plates 21 are joined to each other by resin 31. Note that the resin 31 is preferably a thermosetting resin such as an epoxy resin.

Next, a method for manufacturing the rotor 10 including a method for positioning the rotor core 20 will be described.
First, the jig 40 for positioning the rotor core 20 will be described with reference to FIGS. 3 to 5.

As shown in FIG. 3, the jig 40 includes a base portion 41 that supports the entire lower surface of the rotor core 20, and a substantially cylindrical insertion portion 42 that protrudes from the base portion 41 and is inserted into the center hole 22 of the rotor core 20. It has The jig 40 is made of a metal material such as stainless steel, for example.

An insertion hole 41a into which the proximal end of the insertion portion 42 is inserted is provided in the center of the base portion 41. A bearing 46 that rotatably supports the insertion portion 42 is provided in the insertion hole 41a.

A base end of the insertion section 42 is connected to an output shaft of a servo motor M that rotationally drives the insertion section 42 . Therefore, the insertion section 42 of this embodiment is rotatably provided with respect to the base section 41.

As shown in FIGS. 4 and 5, the insertion portion 42 has a cylindrical main body portion 43. As shown in FIGS. The diameter of the main body portion 43 is smaller than the diameter of the center hole 22.
In addition, the insertion portion 42 has a pair of protrusions 44 that protrude radially outward from the main body portion 43 and extend along the direction in which the insertion portion 42 protrudes. The protrusion 44 extends throughout the insertion portion 42 in the above-mentioned protruding direction. The pair of protrusions 44 are provided on opposite sides of the central axis of the insertion portion 42 .

As shown in FIG. 5, the outer circumferential surface 44a of the protrusion 44 is curved along the inner circumferential surface 22a of the center hole 22 with substantially the same radius of curvature as the center hole 22. As shown in FIG. Therefore, the maximum value of the diameter of the insertion portion 42, that is, the distance between the outer peripheral surfaces 44a in the radial direction, is approximately the same as the diameter of the center hole 22.

The first side surface 44b on one circumferential side of the protrusion 44 is a plane perpendicular to the circumferential direction. The second side surface 44c on the other side in the circumferential direction of the protrusion 44 is an inclined surface that is inclined so as to be located on the other side in the circumferential direction toward the inside in the radial direction.

The maximum width of the protrusion 44 in the circumferential direction, that is, the maximum value of the distance between the first side surface 44b and the second side surface 44c, is smaller than the maximum value of the opening width of the recessed portion 24 in the circumferential direction.
Further, the insertion portion 42 has a pair of groove portions 45 provided adjacent to one side of each protrusion 44 in the circumferential direction. The groove portion 45 is provided so as to be continuous with the protrusion 44 . The groove portion 45 is recessed inward in the radial direction from the tip of the key portion 23 . The bottom surface 45a of the groove portion 45 is curved along the inner circumferential surface 22a of the center hole 22 with a radius of curvature smaller than that of the center hole 22.

The first side surface 45b on one circumferential side of the groove portion 45 and the second side surface 45c on the other circumferential side are both planes perpendicular to the circumferential direction.
The first side surface 44b of the protrusion 44 and the second side surface 45c of the groove portion 45 are located on the same plane and are continuous.

Next, a method for manufacturing the rotor 10 will be explained.
As shown in FIG. 3, first, the insertion portion 42 of the jig 40 is inserted into the center hole 22 of the rotor core 20. At this time, as shown in FIGS. 4 and 5, the insertion part 42 is inserted into the center hole 22 with the protrusion 44 facing the recessed part 24 adjacent to the key part 23 on the other side in the circumferential direction.

Here, as described above, the diameter of the main body portion 43 is smaller than the diameter of the center hole 22. Further, the maximum width of the protrusion 44 in the circumferential direction is smaller than the maximum opening width of the recess 24 in the circumferential direction. Furthermore, the groove portion 45 is recessed inward in the radial direction from the tip of the key portion 23 . From the above, the insertion portion 42 is loosely fitted into the center hole 22. In other words, the insertion portion 42 is inserted into the center hole 22 with a gap provided between it and the inner circumferential surface 22a of the center hole 22. Hereinafter, the position of the insertion portion 42 with respect to the rotor core 20 at this time will be referred to as the insertion position.

As shown in FIG. 6, next, by driving the servo motor M, the insertion portion 42 is rotated about the central axis C from one side in the circumferential direction to the other side. Thereby, the protrusion 44 slides on the inner circumferential surface 22a of the center hole 22. Therefore, the outer circumferential surface 44a of the protrusion 44 and the inner circumferential surface 22a of the center hole 22 are in contact with each other in the radial direction. Further, as the groove portion 45 moves from one side in the circumferential direction to the other side, the first side surface 45b of the groove portion 45 and the side surface 23a on one side in the circumferential direction of the key portion 23 come into contact in the circumferential direction. This restricts rotation of the insertion portion 42 from one side in the circumferential direction to the other side. Hereinafter, the position of the insertion portion 42 with respect to the rotor core 20 at this time will be referred to as a restriction position.

Note that when the insertion portion 42 in this embodiment is rotated, the outer circumferential surface of the rotor core 20 is supported by a jig (not shown). Thereby, rotation of the rotor core 20 is restricted by the rotation of the insertion portion 42, more specifically, by the frictional force generated between the insertion portion 42 and the rotor core 20.

As shown in FIG. 7, the magnets 30 are then accommodated in each magnet accommodation hole 25 of the rotor core 20.
As shown in FIG. 8, next, a cull plate 50 is placed on the upper surface of the rotor core 20. The cull plate 50 has a plurality of injection ports 51 connected to each magnet housing hole 25 . By injecting the resin 31 into each injection port 51, the inside of each magnet accommodation hole 25 is filled with the resin 31 via the cull plate 50.

Next, the entire rotor core 20 is heated by a heating device (not shown), thereby thermosetting the thermosetting resin 31. As a result, the steel plates 21 are joined together, and the magnets 30 are fixed to the rotor core 20.

The rotor 10 is manufactured in this way.
Note that when removing the jig 40 from the rotor 10, the position of the insertion part 42 is switched from the regulation position to the insertion position by rotating the insertion part 42 from the other side to the one side in the circumferential direction. .

The operation of this embodiment will be explained.
By rotating the insertion portion 42 of the jig 40 loosely fitted into the center hole 22 with respect to the rotor core 20, the outer circumferential surface 44a of the protrusion 44 and the inner circumferential surface 22a of the center hole 22 come into contact in the radial direction. As a result, each steel plate 21 is positioned in the radial direction. Since the insertion portion 42 is loosely fitted into the center hole 22, the jig 40 can be easily attached to and removed from the rotor core 20. Further, each steel plate 21 is positioned in the radial direction by a simple method of rotating the insertion portion 42 relative to the rotor core 20 between the insertion position and the restriction position.

The effects of this embodiment will be explained.
(1) After loosely fitting the insertion part 42 of the jig 40 into the center hole 22, by rotating the insertion part 42 with respect to the rotor core 20 around the central axis C of the center hole 22, The inner circumferential surface 22a of the center hole 22 and the outer circumferential surface 44a of the protrusion 44 are brought into contact to position each steel plate 21 in the radial direction.

According to such a method, the rotor core 20 can be easily positioned because the above-mentioned effect is achieved.
(2) By rotating the insertion portion 42 with respect to the rotor core 20, the side surface 23a of the key portion 23 and the first side surface 45b of the groove portion 45 are brought into contact with each other in the circumferential direction of the rotor core 20, thereby positioning each steel plate 21 in the circumferential direction. I do.

According to such a method, since each steel plate 21 is positioned in the circumferential direction, the positioning accuracy of the rotor core 20 can be improved.
Furthermore, in the rotor core 20, since the positions of the magnet housing holes 25 in the circumferential direction are aligned, the magnets 30 can be easily accommodated in the magnet housing holes 25. Therefore, the rotor core 20 can be easily manufactured.

(3) By rotating the insertion portion 42 of the jig 40 with respect to the rotor core 20, the inner peripheral surface 22a of the center hole 22 and the outer peripheral surface 44a of the protrusion 44 are brought into contact.
For example, when rotating the rotor core 20 with respect to the jig 40, it is necessary to hold the rotor core 20 and rotate each steel plate 21 at once, so the device for holding the rotor core 20 may become complicated. be.

In this regard, according to the positioning method of this embodiment, since the insertion portion 42 of the jig 40 is rotated with respect to the rotor core 20, the above-mentioned inconvenience can be suppressed from occurring. Therefore, the rotor core 20 can be positioned even more easily.

<Example of change>
This embodiment can be modified and implemented as follows. This embodiment and the following modified examples can be implemented in combination with each other within a technically consistent range.

In addition, in the first modified example and the second modified example shown in FIGS. 9 to 11 below, the same components as in the above embodiment are given the same reference numerals, and the corresponding components are given the same reference numerals as in the above embodiment. **'' and ``100'' and ``200'', respectively, to omit redundant explanation.

- In this embodiment, the rotor core 20 is positioned by rotating the insertion part 42 of the jig 40 with respect to the rotor core 20. However, by rotating the rotor core 20 with respect to the jig 40, the rotor core 20 is positioned. Positioning may also be performed. Alternatively, the rotor core 20 may be positioned by rotating the jig 40 and the rotor core 20 in mutually opposite directions in the circumferential direction.

- As shown in FIGS. 9 and 10, the insertion section 142 has a pair of cylindrical pins 60 that move along the circumferential direction in synchronization with the rotation of the main body section 143 instead of each groove section 45. There may be. According to this configuration, since the pin 60 comes into contact with the side surface 23a of the key part 23 as the main body part 143 rotates, an effect similar to the above-mentioned effect (2) can be achieved. Moreover, such a pin 60 can also be provided, for example, at a position corresponding to a lightening hole provided through the rotor core 20 in the axial direction. Even with this configuration, since the outer circumferential surface of the pin 60 and the inner circumferential surface of the lightening hole come into contact with each other by rotating the main body portion 143, an effect similar to the above-mentioned effect (2) can be achieved. I can do it.

- The groove portion 45 can also be omitted. Even with this configuration, an effect similar to the above-mentioned effect (1) can be achieved. Further, according to this configuration, as shown in FIG. 11, even if the rotor core 20 is provided with the center hole 22 without the key portion 23, the outer circumferential surface of the protrusion 244 and the inner circumference of the center hole 22 The surface 22a contacts in the radial direction. Therefore, each steel plate 21 can be positioned in the radial direction. Note that the center hole 22 of this modification has three recesses 224 provided at intervals in the circumferential direction. The insertion portion 242 has three protrusions 244 provided corresponding to each recess 224 . As shown by the two-dot chain line in the figure, by rotating the insertion portion 242 in the circumferential direction, the protrusion 244 slides on the inner circumferential surface 22a of the center hole 22.

- The servo motor M can also be omitted. In this case, the insertion portion 42 may be rotated by engaging a tool or the like with the end of the insertion portion 42 and rotating the tool around the central axis C.

- Even when the steel plates 21 are joined to each other by welding the outer peripheral surface of the rotor core 20, or when the steel plates 21 are caulked together in the axial direction, the laminated core positioning method in this embodiment is applied. be able to.

- The method for positioning a laminated core of this embodiment can also be applied to a rotor core configured by laminating a plurality of core blocks in which a plurality of steel plates 21 are caulked together.

- In the present embodiment, a method for positioning the rotor core 20 of a rotating electric machine is illustrated as an example of a method for positioning a laminated core, but it is also possible to apply a similar method to a method for positioning a stator core of a rotating electric machine.

C... Central axis M... Servo motor 10... Rotor 20... Rotor core 21... Steel plate 22... Center hole 22a... Inner peripheral surface 23... Key part 23a... Side surface 24, 224... Hollow part 25... Magnet housing hole 30... Magnet 31... Resin 40...Jig 41...Base part 41a...Insertion hole 42,142,242...Insertion part 43,143,243...Body part 44,144,244...Protrusion 44a, 144a...Outer peripheral surface 44b, 144b...First side surface 44c , 144c...Second side surface 45...Groove portion 45a...Bottom surface 45b...First side surface 45c...Second side surface 46...Bearing 50...Cull plate 51...Inlet 60...Pin

Claims (4)

A method for positioning a laminated core configured by laminating a plurality of steel plates and positioning each of the steel plates in a laminated core having a center hole, the method comprising:
After loosely fitting a jig into the center hole, the inner peripheral surface of the center hole is rotated relative to the laminated core around the central axis of the center hole in the radial direction of the laminated core. and the outer circumferential surface of the jig to position each of the steel plates in the radial direction;
How to position a laminated core. A method for positioning a laminated core configured by laminating a plurality of steel plates and positioning each of the steel plates in a laminated core having a center hole, the method comprising:
After the jig is loosely fitted into the center hole, the jig and the laminated core are rotated relative to each other about the central axis of the center hole, so that the inner peripheral surface of the center hole is fixed in the radial direction of the laminated core. and the outer circumferential surface of the jig to position each of the steel plates in the radial direction, and the inner circumferential surface of the center hole and the outer circumferential surface of the jig are brought into contact in the circumferential direction of the laminated core. positioning each of the steel plates in the circumferential direction,
How to position a laminated core. By relatively rotating the jig and the laminated core, the inner circumferential surface of the center hole and the outer circumferential surface of the jig are brought into contact in the circumferential direction of the laminated core, and the inner circumferential surface of each of the steel plates is rotated in the circumferential direction. perform positioning,
A method for positioning a laminated core according to claim 1. By rotating the jig with respect to the laminated core, the inner circumferential surface of the laminated core and the outer circumferential surface of the jig are brought into contact;
A method for positioning a laminated core according to claim 2 .