JP2023017327A - Rotor core manufacturing method and rotor core manufacturing device - Google Patents

Abstract

To provide a rotor core manufacturing method that can improve productivity of a rotor core.SOLUTION: A rotor core manufacturing method according to the embodiment manufactures a rotor core that has a shaft hole 11 penetrated through in an axial direction and a key part 12 protruded inward in a radial direction to an inner periphery of the shaft hole 11 and is configured by laminating a plurality of tabular rotor core members 20 in a thickness direction while rotating the members in a circumferential direction. The rotor core manufacturing method includes: a first through-hole forming step in which first through-holes 101 for respectively forming contours of a plurality of convex parts 104 including the convex parts 104 constituting the key part are punched with respect to an electromagnetic steel plate 100; a second through-hole forming step of forming second through-holes 111 by cutting off some convex parts 104 of the plurality of convex parts 104; and a shaft hole forming step of forming the shaft holes 11, by punching out a region which overlaps at least partially to the first through-holes 101 and the second through-holes 111 in plan view of the electromagnetic steel plate 100, with respect to the electromagnetic steel plate 100.SELECTED DRAWING: Figure 4

Description

The present invention relates to a rotor core manufacturing method and a rotor core manufacturing apparatus.

As a rotor core manufacturing method, a method is known in which a steel plate is punched into the shape of a rotor core member using a press machine or the like, and a plurality of the punched rotor core members are laminated in the thickness direction.

As a rotor core manufacturing method as described above, for example, a rotor core manufacturing method disclosed in Patent Document 1 is known. The manufacturing method of the rotor core disclosed in Patent Document 1 includes forming the outline of the key portion in the strip-shaped thin metal plate, the inner region located inside the shaft hole, and the inner region continuing to the inner region of the shaft hole. A first step of punching and forming a punched hole having an outer region positioned outside; a second step of punching and forming a shaft hole communicating with the punched hole; and a third step of laminating.

In the rotor core manufacturing method disclosed in Patent Document 1, in the first step, punched holes forming key portions are formed in the first core piece at the 0-degree position and the 180-degree position. 2, punched holes forming key portions are formed at the 90-degree position and the 270-degree position. In the rotor core manufacturing method, the rotor core is obtained by alternately laminating the first core pieces and the second core pieces while performing 90-degree rotation.

JP 2014-171329 A

In the rotor core manufacturing method disclosed in the above-mentioned Patent Document 1, two types of core pieces, ie, first core pieces and second core pieces, are formed in the first step. In such a manufacturing method, for example, when manufacturing a rotor core in which the key portion is skewed in the circumferential direction of the rotor core (rotor core), in addition to the two types of core pieces described above, the keys of the respective types of core pieces It is necessary to form the core piece having the key portion at a position displaced in the circumferential direction with respect to the portion. Therefore, when manufacturing the rotor core using the manufacturing method, it is necessary to form a total of four types of core pieces. Since the manufacturing method requires steps for forming each type of core piece, four steps are required to form four types of core pieces.

As described above, in the manufacturing method disclosed in Patent Document 1, when manufacturing a rotor core in which the key portion is skewed in the circumferential direction of the rotor core (rotor core), the number of steps increases, and the rotor core is manufactured. takt time increases. On the other hand, there is a demand for a rotor core manufacturing method capable of shortening the tact time for manufacturing the rotor core and improving the productivity of the rotor core.

An object of the present invention is to provide a rotor core manufacturing method capable of improving the productivity of rotor cores.

A rotor core manufacturing method according to an embodiment of the present invention includes a plurality of plate-shaped rotor cores each having a shaft hole penetrating in an axial direction and a key portion protruding radially inward on an inner circumference of the shaft hole. In this rotor core manufacturing method, members are laminated in the thickness direction while being rotated in the circumferential direction. This rotor core manufacturing method includes: a first through hole forming step of punching a plate material to form first through holes respectively forming contours of a plurality of convex portions including a convex portion constituting the key portion; A second through-hole forming step of forming a second through-hole by removing a part of the convex portion of the plate, and forming the first through-hole and the second through-hole in a plan view of the plate with respect to the plate and a shaft hole forming step of forming a through hole that constitutes a part of the shaft hole by punching a region that at least partially overlaps with the hole.

A rotor core manufacturing apparatus according to an embodiment of the present invention includes a plurality of plate-like rotor cores each having a shaft hole penetrating in an axial direction and a key portion protruding radially inward on an inner circumference of the shaft hole. A rotor core manufacturing apparatus for manufacturing a rotor core configured by laminating members in a thickness direction while rotating in a circumferential direction. This rotor core manufacturing apparatus includes a first through-hole forming section for punching out first through-holes for respectively forming contours of a plurality of projections constituting the key portion, and a part of the plurality of projections. a second through-hole forming portion that forms a second through-hole by cutting off the convex portion of the plate member; and a shaft hole forming portion that forms a through hole that constitutes a part of the shaft hole by punching a region where the portions overlap.

According to the rotor core manufacturing method according to the embodiment of the present invention, it is possible to realize a rotor core manufacturing method capable of improving the productivity of the rotor core.

FIG. 1 is a perspective view showing a schematic configuration of a rotor core according to the embodiment. FIG. 2 is a plan view showing a schematic configuration of a rotor core member forming the rotor core. FIG. 3 is a flow chart showing an example of a rotor core manufacturing method. FIG. 4 is a plan view schematically showing an example of a method of manufacturing a rotor core member from an electromagnetic steel sheet. FIG. 5 is a plan view schematically showing an example of a method of manufacturing a rotor core member from an electromagnetic steel sheet. FIG. 6 is an enlarged view of the first through hole. FIG. 7 is a diagram schematically showing an example of forming a rotor core by rolling rotor core members. FIG. 8 is a diagram schematically showing an example of a rotor core manufacturing apparatus. FIG. 9 is a diagram schematically showing an example of a punch driving mechanism of the second through-hole forming portion. FIG. 10 is a diagram schematically showing an example of a punch drive mechanism of the second through-hole forming portion.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. The same or corresponding parts in the drawings are denoted by the same reference numerals, and the description thereof will not be repeated. Also, the dimensions of the constituent members in each drawing do not faithfully represent the actual dimensions of the constituent members, the dimensional ratios of the respective constituent members, and the like.

In the following description, the direction parallel to the central axis P of the rotor core 1 is referred to as the "axial direction," the direction perpendicular to the central axis P is the "radial direction," and the direction along the arc centered on the central axis P is the "circumferential direction." direction”, respectively. However, this definition of direction is not intended to limit the direction of use of the motor having the rotor core 1 according to the present invention.

In the following description, expressions such as "fixed", "connected" and "attached" are used not only when members are directly fixed to each other, but also when members are fixed via other members. Also includes That is, in the following description, expressions such as fixing include meanings such as direct and indirect fixing between members.

(Configuration of rotor core)
FIG. 1 is a diagram showing a schematic configuration of a rotor core 1 according to an embodiment of the invention. The rotor core 1 forms part of the rotor of a motor (not shown). The rotor core 1 is a cylindrical member configured by stacking a plurality of disk-shaped rotor core members 20 in the thickness direction. That is, the rotor core 1 has a cylindrical shape extending along the central axis P. As shown in FIG.

Although not shown, the rotor core 1 may have, for example, a magnet insertion hole into which the rotor magnet is inserted, or may have a recess for arranging the rotor magnet on the radially outer side. good.

The rotor core 1 has an axial hole 11 extending along the central axis P in the center of the rotor core 1 when viewed in the axial direction, which is the direction in which the central axis P extends. A shaft of a rotor (not shown) passes through the shaft hole 11 .

The rotor core 1 has a plurality of key portions 12 projecting inwardly of the shaft hole 11 on the inner surface of the shaft hole 11 . In this embodiment, the rotor core 1 has two key portions 12 on the inner surface of the shaft hole 11 .

The two key portions 12 are located on the inner surface of the shaft hole 11 and at opposing positions when the rotor core 1 is viewed in the axial direction. The two key portions 12 each have a rectangular shape when the rotor core 1 is viewed in the axial direction. The two key portions 12 each extend in the axial direction on the inner surface of the shaft hole 11 .

The two key portions 12 are fitted into recesses provided on the outer peripheral surface of the shaft of the rotor (not shown). Thereby, the rotation of the shaft can be transmitted to the rotor core 1 . Therefore, the rotor core 1 rotates together with the shaft.

FIG. 2 is a diagram showing a schematic configuration of a rotor core member 20 forming the rotor core 1. As shown in FIG. As shown in FIG. 2, the rotor core member 20 is a disk-shaped electromagnetic steel plate, and has a through hole 21 in the center in plan view. Through hole 21 forms part of shaft hole 11 .

The rotor core member 20 has a plurality of protrusions 22 on the inner peripheral side of the through hole 21 . The plurality of protruding portions 22 are located at opposing positions on the inner peripheral side of the through hole 21 in a plan view of the rotor core member 20 . In this embodiment, the rotor core member 20 has a pair of protrusions 22 . The pair of protruding portions 22 form part of the key portion 12 .

Although the details will be described later, a plurality of rotor core members 20 constituting the rotor core 1 are stacked in a state rotated by a predetermined angle in the circumferential direction. That is, the rotor core 1 is constructed by rolling a plurality of rotor core members 20 . Accordingly, as will be described later, variations in the magnetic properties of the rotor core member 20 formed from the electromagnetic steel sheets 100 can be reduced, so the magnetic properties of the rotor core 1 can be improved.

(Manufacturing method of rotor core)
Next, a method of manufacturing the rotor core 1 having the above configuration will be described. FIG. 3 is a flow chart showing an example of a method for manufacturing the rotor core 1. As shown in FIG. 4 and 5 are diagrams schematically showing an example of a method of manufacturing the rotor core member 20 from the strip-shaped electromagnetic steel sheet 100. FIG. FIG. 6 is an enlarged view of the first through hole 101. As shown in FIG. FIG. 7 is a diagram schematically showing how the rotor core member 20 is rolled in the thickness direction.

4 and 5, illustration of a rotor magnet insertion hole for inserting a rotor magnet is omitted. In the following description, the description of the manufacturing method of the rotor magnet insertion holes and the like in the rotor core member 20 will be omitted.

As shown in FIG. 3, the rotor core 1 first forms a plurality of first through holes 101 in the strip-shaped electromagnetic steel sheet 100 in the first through hole forming step of step S1. In this embodiment, in the first through hole forming step, four first through holes 101 are formed in the electromagnetic steel sheet 100 at intervals of 90 degrees in the circumferential direction. Of the four first through holes 101, a pair of first through holes 101 are arranged in the short side direction of the electromagnetic steel sheet 100, and the other pair of first through holes 101 are arranged in the long side direction of the electromagnetic steel sheet 100. Lined up. The electromagnetic steel sheet 100 corresponds to the plate material of the present invention.

The first through-hole 101 is a C-shaped through-hole in plan view, as shown in FIG. More specifically, the first through hole 101 includes a first slit 102 extending in the first direction and a pair of second slits 102 extending from both ends of the first slit 102 in a second direction orthogonal to the first direction and in the same direction. and a slit 103 . The first slit 102 and the pair of second slits 103 are connected. The length of the pair of second slits 103 in the second direction is shorter than the length of the first slits 102 in the first direction. Note that the first direction is the longitudinal direction of the first slit 102 .

As shown in FIGS. 4 and 5 , the first slit 102 is closer to the center C of the rotor core member 20 than the pair of second slits 103 . The first slit 102 and the pair of second slits 103 form a convex portion 104 projecting toward the center C in the electromagnetic steel sheet 100 in plan view. That is, the electromagnetic steel sheet 100 is formed with a plurality of protrusions 104 protruding toward the center C by the plurality of first through holes 101 . Thus, in the first through-hole forming step, the plurality of first through-holes 101 that form the contours of the plurality of protrusions 104 are formed. The plurality of protrusions 104 includes protrusions 104 that become the protrusions 22 of the rotor core member 20 that constitutes the key portion 12 of the rotor core 1 .

In this embodiment, four convex portions 104 are formed on the electromagnetic steel sheet 100 at intervals of 90 degrees in the circumferential direction. Of the four protrusions 104 , a pair of protrusions 104 are aligned in the short side direction of the electromagnetic steel sheet 100 , and the other pair of protrusions 104 are aligned in the long side direction of the electromagnetic steel sheet 100 .

Next, a plurality of second through holes 111 are formed in the electromagnetic steel sheet 100 in the second through hole forming step of step S2 shown in FIG. The second through-hole 111 has a rectangular shape in a plan view, and has a size that allows the protrusion 104 formed by the first through-hole 101 to be excised. The second through holes 111 are formed at positions where some of the plurality of protrusions 104 formed by the plurality of first through holes 101 are removed.

Specifically, the second through hole 111 allows a pair of protrusions 104 aligned in the short side direction of the electromagnetic steel sheet 100 or another pair of protrusions 104 aligned in the long side direction of the electromagnetic steel sheet 100 to be formed. It is formed at the location of excision. FIG. 4 shows a case where a pair of protrusions 104 aligned in the short side direction of the electromagnetic steel sheet 100 are cut out by the second through holes 111 . FIG. 5 shows a case where another pair of protrusions 104 aligned in the long side direction of the electromagnetic steel sheet 100 is removed by the second through holes 111 .

Cutting off the projection 104 includes not only cutting only the projection 104 but also forming a punched hole in a predetermined range including the projection 104 .

In the manufacturing process of the rotor core 1, as the second through-hole forming process, the pair of protrusions 104 aligned in the long side direction of the electromagnetic steel sheet 100 are removed by the second through-hole 111, By 111, the other pair of protrusions 104 aligned in the short side direction of the electromagnetic steel sheet 100 are cut off alternately. That is, in the present embodiment, the second through-hole forming step includes, as shown in FIG. and a second projection cutting step of cutting out the other pair of projections 104 that face each other in the radial direction among the four projections 104 as shown in FIG. In the second through-hole forming step of the present embodiment, the first protrusion cutting step and the second protrusion cutting step are alternately performed. In FIG. 4, a pair of second through-holes 111 are formed in the electromagnetic steel sheet 100 so as to be aligned in the long side direction. In FIG. 5, a pair of second through-holes 111 are formed in the electromagnetic steel sheet 100 so as to be aligned in the short side direction. The protrusions 104 left uncut in the second through-hole forming step become the protrusions 22 of the rotor core member 20 .

By forming the second through-holes 111 by the second through-hole forming process described above, the rotor core in which the pair of protrusions 104 arranged in the longitudinal direction of the electromagnetic steel sheet 100 are removed after steps S3 and S4 described later. The members 20 and the rotor core members 20 from which the other pair of projections 104 arranged in the short side direction of the electromagnetic steel plate 100 are cut are alternately manufactured.

After the step of removing the pair of protrusions 104 aligned in the longitudinal direction of the electromagnetic steel sheet 100 by the second through holes 111 is performed a predetermined number of times as the second through hole forming step, the second through holes 111 are formed. A step of cutting out the other pair of protrusions 104 aligned in the short side direction of the electromagnetic steel sheet 100 by the hole 111 may be performed as the second through hole forming step. After the step of cutting off the other pair of protrusions 104 aligned in the short side direction of the electromagnetic steel sheet 100 by the second through holes 111 is performed a predetermined number of times as the second through hole forming step, the second through holes 111 are formed. A step of cutting out the pair of protrusions 104 aligned in the longitudinal direction of the electromagnetic steel sheet 100 by the hole 111 may be performed as the second through hole forming step. As described above, in the second through-hole forming step, the positions of the protrusions 104 to be cut out of the plurality of protrusions 104 may be changed each time the electromagnetic steel sheet 100 is punched a predetermined number of times. The predetermined number of times may be one time or a plurality of times.

Next, in the shaft hole forming step of step S3 shown in FIG. As shown in FIGS. 4 and 5, the through-hole 21 is a through-hole that connects the plurality of first through-holes 101 and the plurality of second through-holes 111 . Specifically, the through holes 21 are connected to the pair of second slits 103 in the plurality of first through holes 101 and to the pair of second through holes 111 . The through-holes 21 are connected to the pair of second slits 103 on the side opposite to the first slits 102 in the second direction shown in FIG. As shown in FIGS. 4 and 5, the through-holes 21 are connected to the pair of rectangular second through-holes 111 on the short side. In this manner, the through-holes 21 are formed by punching regions of the electromagnetic steel sheet 100 that at least partially overlap with the first through-holes 101 and the second through-holes 111 .

As a result, the through hole 21 having the projecting portion 22 on the inner peripheral side is formed in the electromagnetic steel sheet 100 . Moreover, when the through-holes 21 are formed, the through-holes 21 are connected to the pair of second slits 103 and the pair of second through-holes 111 . It is possible to prevent the peripheral portion of the through hole 111 from being removed twice.

In the axial hole forming step, as will be described later, a punch and a die having concave portions along the shapes of the convex portions 104 that are not cut out in the second through hole forming step are used. is used to form the through holes 21 in the electromagnetic steel sheet 100 .

In the outer shape punching process of step S4 shown in FIG. Thereby, the rotor core member 20 is obtained. Although omitted in the above description, the rotor core member 20 is also formed with rotor magnet insertion holes and the like. Therefore, when punching the outer shape of the rotor core member 20 from the electromagnetic steel sheet 100 , the electromagnetic steel sheet 100 is punched after the rotor magnet insertion holes and the like are also formed in the electromagnetic steel sheet 100 .

Then, in the rotor core member stacking step of step S5 shown in FIG. 3, a plurality of rotor core members 20 are stacked in the thickness direction. Specifically, the rotor core member 20 from which a pair of protrusions 104 aligned in the long side direction of the electromagnetic steel sheets 100 has been removed, and another pair of protrusions 104 aligned in the short side direction of the electromagnetic steel sheets 100 have been removed. The rotor core members 20 are alternately laminated in the thickness direction. As shown in FIG. 7, the rotor core member 20 from which the other pair of protrusions 104 aligned in the short side direction of the electromagnetic steel sheet 100 are removed is the pair of protrusions 104 aligned in the long side direction of the electromagnetic steel sheet 100 . are laminated on the rotor core member 20 from which the . Thus, the plurality of rotor core members 20 are rolled up.

By the method described above, the rotor core 1 in which the plurality of rotor core members 20 are laminated in the thickness direction is obtained.

The rotor core manufacturing method of the present embodiment includes a plurality of plate-like rotor core members 20 each having a shaft hole 11 penetrating in the axial direction and a key portion 12 protruding radially inward from the inner circumference of the shaft hole 11 . is laminated in the thickness direction while rotating in the circumferential direction. In the rotor core manufacturing method of the present embodiment, the first through holes 101 are punched in the electromagnetic steel sheet 100 to form the contours of the plurality of protrusions 104 including the protrusions 104 forming the key portion 12 . a second through-hole forming step of forming second through-holes 111 by cutting some of the plurality of convex portions 104; and a shaft hole forming step of forming a through hole 21 that constitutes a part of the shaft hole 11 by punching a region that at least partially overlaps the first through hole 101 and the second through hole 111 visually.

As a result, the rotor core 1 having the key portion 12 on the inner circumference of the shaft hole 11 can be formed by laminating the plate-like rotor core members 20 in the thickness direction while rotating in the circumferential direction. That is, by cutting out a part of the plurality of protrusions 104 in the second through-hole forming step, even when the rotor core member 20 is laminated in the thickness direction while being rotated in the circumferential direction, the key portion 12 can be formed in the rotor core 1 at the same position in the circumferential direction on the inner periphery of the shaft hole 11 .

By the way, for example, when the key portion 12 is skewed in the circumferential direction of the shaft hole 11 , it is necessary to form the convex portion 104 in the rotor core member 20 at a position shifted in the circumferential direction of the shaft hole 11 . In this case, if two types of rotor core members are formed in which the positions of the protrusions 104 differ by the rotation angle in the circumferential direction in order to stack the rotor core members 20 in the thickness direction while rotating the rotor core member 20 in the circumferential direction, the rotor core members of the respective types have Also, it is necessary to prepare a rotor core member in which the positions of the protrusions 104 are shifted in the circumferential direction. Therefore, it is necessary to prepare a total of four types of rotor core members. If four types of rotor core members are to be prepared in this manner, four processes are required.

On the other hand, in the above-described configuration, the positions of the remaining protrusions 104 are controlled by cutting out some of the plurality of protrusions 104 formed in the first through-hole forming step in the second through-hole forming step. can. Therefore, in the case of the configuration in which the key portion 12 is skewed in the circumferential direction of the shaft hole 11, if two types of rotor core members having the convex portions 104 shifted in the circumferential direction are prepared, the convex portions 104 left in the second through hole forming step can be obtained. By controlling the position of , the four types of rotor core members described above can be obtained. Thus, with the above configuration, four types of rotor core members can be obtained in three steps.

Therefore, as described above, the tact time can be reduced in the rotor core manufacturing method that requires the preparation of four or more types of rotor core members. Therefore, productivity of the rotor core 1 can be improved. Moreover, the rotor core manufacturing apparatus 200 that manufactures the rotor core 1 can be miniaturized as much as the number of processes is small.

In the present embodiment, in the axial hole forming step, the electromagnetic A through hole 21 is formed in the steel plate 100 .

As a result, the projecting portion 22 forming the key portion 12 and the through hole 21 can be accurately formed while suppressing the generation of chips when forming the through hole 21 in the electromagnetic steel sheet 100 .

In the present embodiment, the electromagnetic steel sheet 100 having the through-holes 21 formed therein is punched out in the shape of the rotor core member 20, thereby forming the rotor core member 20 in the shape punching step and rotating the rotor core member 20 in the circumferential direction. and a rotor core member laminating step of obtaining the rotor core 1 by laminating the rotor core members.

The magnetic steel sheet 100 used to form the rotor core member 20 may have variations in thickness and magnetic properties due to rolling. By laminating the rotor core member 20 in the thickness direction while rotating the rotor core member 20 in the circumferential direction as described above, it is possible to suppress variations in the dimensions of the rotor core 1 in the lamination direction due to unevenness in the thickness of the rotor core member 20. characteristics can be averaged.

In the present embodiment, in the second through hole forming step, the positions of the protrusions 104 to be cut out of the plurality of protrusions 104 are changed each time the electromagnetic steel sheet 100 is punched a predetermined number of times.

As a result, the position of the protrusion 104 left on the inner periphery of the through-hole 21 can be easily changed depending on whether the portion to be the rotor core member 20 is punched first or the portion to be the rotor core member 20 is punched next. can. When the rotor core member 20 is laminated in the thickness direction while rotating in the circumferential direction, it is necessary to change the position of the protrusion 104 left on the inner circumference of the through hole 21 in order to form the key portion 12 on the inner circumference of the rotor core 1 . . With the above-described configuration, when the rotor core members 20 are stacked in this way, the position of the convex portion 104 left on the inner periphery of the through hole 21 can be easily changed. Therefore, the rotor core 1 can be easily formed using the rotor core member 20 .

In the present embodiment, in the first through-hole forming step, as the plurality of protrusions 104, four protrusions 104 are formed on the electromagnetic steel sheet 100 at regular intervals in the circumferential direction. In the second through-hole forming step, a first protrusion cutting step of cutting out a pair of protrusions 104 of the four protrusions 104 that face each other in the radial direction; and a second protrusion cutting step of cutting the other pair of protrusions 104 . In the rotor core member stacking step, the rotor core member 20 from which the pair of protrusions 104 have been removed is rotated 90 degrees in the circumferential direction, while the rotor core member 20 from which the other pair of protrusions 104 have been removed is rotated in the thickness direction. to laminate.

As a result, the pair of key portions 12 can be formed on the inner circumference of the shaft hole 11 in the rotor core 1 formed by stacking the rotor core members 20 in the thickness direction while rotating the rotor core member 20 by 90 degrees in the circumferential direction.

(Rotor core manufacturing equipment)
Next, a rotor core manufacturing apparatus 200 for realizing the manufacturing method of the rotor core 1 as described above will be described. FIG. 8 is a diagram showing a schematic configuration of a rotor core manufacturing apparatus 200. As shown in FIG.

As shown in FIG. 8 , rotor core manufacturing apparatus 200 has first through hole forming portion 210 , second through hole forming portion 220 , shaft hole forming portion 230 , and outline punching portion 240 .

The first through-hole forming part 210 forms a plurality of first through-holes 101 for forming a plurality of protrusions 104 in the electromagnetic steel sheet 100 . The first through hole forming part 210 has a first fixed mold 211 and a first movable mold 212 . For example, the first movable mold 212 has a first punch 213 that forms the first through hole 101 . By moving the first movable mold 212 in the direction of the white arrow in FIG. .

The second through-hole forming part 220 forms a plurality of second through-holes 111 in the electromagnetic steel sheet 100 . The second through hole forming part 220 has a second fixed mold 221 and a second movable mold 222 . For example, the second movable mold 222 has a second punch 223 that forms the second through hole 111 . By moving the second movable mold 222 in the direction of the white arrow in FIG. .

The second through-hole forming portion 220 forms the second through-holes 111 in the electromagnetic steel sheet 100 , thereby forming part of the convex portions 104 among the plurality of convex portions 104 formed by the plurality of first through-holes 101 . excise. The second through-hole forming portion 220 changes the protrusions 104 to be cut out of the plurality of protrusions 104 according to the order in which the rotor core member 20 is punched. In the present embodiment, the second through-hole forming portion 220 is formed by removing a pair of protrusions 104 aligned in the short side direction of the electromagnetic steel sheet 100 among the four protrusions 104 and Cutting of another pair of projections 104 arranged side by side is alternately performed.

The second through-hole forming section 220 has a punch driving mechanism 225 that selects the convex portion 104 to be cut out of the plurality of convex portions 104 . 9 and 10 are diagrams showing an example of a schematic configuration of the punch drive mechanism 225 of the second through hole forming section 220. FIG. In addition, in FIG.9 and FIG.10, only one part of structure is shown in the cross section for description. 9 and 10 schematically show the configuration of the punch drive mechanism 225 that can select punching or non-punching of one projection 104 for the sake of explanation.

The punch drive mechanism 225 has a slide member 226 , a drive portion 227 , a cam 228 and a support portion 229 .

The slide member 226 is a plate-shaped member extending horizontally. One end of the slide member 226 in the longitudinal direction is connected to the drive section 227 . The slide member 226 is movable in the horizontal direction, that is, in the longitudinal direction, by a driving portion 227 . The slide member 226 has a concave portion 226a that can accommodate the end of the cam 228 at the other end in the longitudinal direction.

The driving portion 227 generates a driving force for moving the slide member 226 in the horizontal direction, that is, in the longitudinal direction of the slide member 226 . The driving portion 227 has an actuator 227a such as an air cylinder, and a driving connection portion 227b that can be reciprocated by the actuator 227a. The drive connecting portion 227b is connected to one end of the slide member 226 in the longitudinal direction. As long as the actuator 227a can move the slide member 226 in the horizontal direction, that is, in the longitudinal direction of the slide member 226, the actuator 227a may have another structure such as a piezoelectric element.

The cam 228 is a columnar member extending in the axial direction. The cam 228 is positioned in a through hole 229a provided in the support portion 229 so as to be movable in the axial direction. One axial end of the cam 228 is connected to the second punch 223 . The second punch 223 is also positioned inside the through hole 229a of the support portion 229 so as to be movable in the axial direction.

The other axial end of the cam 228 can be accommodated in the recess 226 a of the slide member 226 .

As shown in FIG. 9, the recess 226a of the slide member 226 is positioned in the axial direction of the cam 228 with respect to the cam 228, and the second movable mold 222 is pressed in a direction to approach the second fixed mold 221. In this case, the cam 228 and the second punch 223 move in the axial direction, and the other axial end of the cam 228 is housed in the recess 226a. Therefore, the second through hole 111 is not formed in the electromagnetic steel sheet 100 by the second punch 223 . That is, the punch driving mechanism 225 positions the second punch 223 at the non-punching position.

On the other hand, as shown in FIG. 10, the second movable mold 222 is brought closer to the second fixed mold 221 while the concave portion 226a of the slide member 226 is positioned with respect to the cam 228 in a direction other than the axial direction of the cam 228. When pressed in the direction, the cam 228 and the second punch 223 do not move axially. Therefore, the second punch 223 forms the second through hole 111 in the electromagnetic steel sheet 100 . That is, the punch drive mechanism 225 positions the second punch 223 at the punching position.

Thus, the punch drive mechanism 225 can position the second punch 223 in the punching position and the non-punching position.

Since the second through-hole forming part 220 has the above-described punch driving mechanism 225, a pair of the four convex parts 104 arranged in the short side direction of the electromagnetic steel sheet 100 is removed and the electromagnetic steel sheet 100 is cut. and the other pair of protrusions 104 aligned in the long side direction can be alternately removed. That is, since the second through-hole forming section 220 has the punch drive mechanism 225 capable of positioning the plurality of second punches 223 at the punching position and the non-punching position, the punch drive mechanism 225 allows some of the second punches 223 to be punched. When the punch 223 is positioned at the punching position and the pair of protrusions 104 is cut off, the punch drive mechanism 225 positions the other second punch 223 at the non-punching position. When the other second punch 223 is positioned at the punching position by the punch driving mechanism 225 and the other pair of convex portions 104 is being cut off, the punch driving mechanism 225 moves the part of the second punch 223 to the non-operating position. Position in punching position.

The shaft hole forming portion 230 forms a through hole 21 in the electromagnetic steel sheet 100 that constitutes a part of the shaft hole 11 of the rotor core 1 . The axial hole forming part 230 has a third fixed mold 231 and a third movable mold 232 . For example, the third movable mold 232 has a third punch 233 that forms the through hole 21 . By moving the third movable mold 232 relative to the third fixed mold 231 in the direction of the white arrow in FIG.

The third punch 233 of the shaft hole forming portion 230 has a concave portion that is recessed along the shape of the convex portion 104 that is not cut off by the second through hole forming portion 220 . Although not shown in particular, the third fixed mold 231 has a die having a concave portion that is recessed along the shape of the convex portion 104 that is not cut off by the second through hole forming portion 220 .

The outer shape punching part 240 punches out the outer shape of the rotor core member 20 from the electromagnetic steel plate 100 . The outer shape punching part 240 has a fourth fixed mold 241 and a fourth movable mold 242 . For example, the fourth movable mold 242 has a fourth punch 243 that punches out the outer shape of the rotor core member 20 . As the fourth movable mold 242 moves relative to the fourth fixed mold 241 in the direction of the white arrow in FIG.

Although not shown in particular, the rotor core manufacturing apparatus 200 also has a rolling section for laminating the rotor core members 20 punched from the electromagnetic steel sheets 100 in the thickness direction while rotating them in the circumferential direction.

A rotor core manufacturing apparatus 200 of the present embodiment has a shaft hole 11 penetrating in the axial direction and a key portion 12 protruding radially inward from the inner periphery of the shaft hole 11, and includes a plurality of plate-like rotor core members. 20 is rotated in the circumferential direction and laminated in the thickness direction to manufacture the rotor core 1 . The rotor core manufacturing apparatus 200 includes a first through-hole forming unit 210 for punching the first through-holes 101 forming outlines of the plurality of convex portions 104 forming the key portion 12 in the electromagnetic steel sheet 100, and a plurality of convex portions. 104, the second through-hole forming part 220 forming the second through-hole 111 and the first through-hole forming part 220 forming the second through-hole 111 and the electromagnetic steel sheet 100 in a plan view of the electromagnetic steel sheet 100 are formed. and a shaft hole forming portion 230 that forms the through hole 21 that constitutes the shaft hole 11 by punching a region that at least partially overlaps with the second through hole 111 and the second through hole 111 .

As a result, a rotor core manufacturing apparatus 200 capable of implementing the manufacturing method of the rotor core 1 described above is obtained.

In the present embodiment, the second through-hole forming part 220 includes a plurality of second punches 223 for respectively cutting out the plurality of protrusions 104, and the positions of the plurality of second punches 223 in the punching direction are divided into punching positions and non-punching positions. and a punch drive mechanism 225 positioned at and. When positioning some of the second punches 223 among the plurality of second punches 223 at the punching position, the punch driving mechanism 225 positions the remaining second punches 223 among the plurality of second punches 223 at the non-punching position. , and the remaining second punches 223 are positioned at the punching positions, the partial second punches 223 are positioned at the non-punching positions.

Accordingly, by switching the positions of a part of the second punches 223 and the remaining second punches 223 of the plurality of second punches 223 when cutting off a portion of the plurality of protrusions 104, , different convex portions 104 out of the plurality of convex portions 104 are cut out in the case where the portion to be the rotor core member 20 is punched first in the electromagnetic steel plate 100 and in the case where the portion to be the rotor core member 20 is punched next in the electromagnetic steel plate 100. be able to. In this manner, different protrusions 104 among the plurality of protrusions 104 can be removed using a single device. Therefore, the rotor core member 20 can be rotated in the circumferential direction while the rotor core manufacturing apparatus 200 is downsized. The rotor core 1 having the key portion 12 on the inner periphery of the shaft hole 11 can be obtained even when the layers are laminated in the thickness direction.

In this embodiment, the punch driving mechanism 225 is a plate-shaped member extending in the longitudinal direction, and moves the plurality of second punches 223 between the punching position and the non-punching position by moving in the longitudinal direction. It has a slide member 226 and a driving section 227 for moving the slide member 226 in the longitudinal direction.

Thereby, the configuration of the punch driving mechanism 225 can be easily realized. Moreover, by moving the slide member 226 in the longitudinal direction by the driving portion 227, the plurality of second punches 223 can be moved between the punching position and the non-punching position. Therefore, the punch driving mechanism 225 can be realized with a compact configuration.

(Other embodiments)
Although the embodiments of the present invention have been described above, the above-described embodiments are merely examples for carrying out the present invention. Therefore, without being limited to the above-described embodiment, it is possible to modify the above-described embodiment as appropriate without departing from the spirit thereof.

In the above embodiment, the rotor core member 20 is rotated 90 degrees in the circumferential direction and laminated in the thickness direction. However, the rotor core member may be rotated at an angle other than 90 degrees and laminated in the thickness direction. In this case, the rotor core members are laminated in the thickness direction while being rotated in the circumferential direction at a rotation angle at which the key portion of the rotor core is formed by the projections of the rotor core members laminated in the thickness direction. Therefore, the convex portion is formed on the inner peripheral side of the through hole of the rotor core member at a position corresponding to the rotational angle of the rotor core member in the circumferential direction.

In the above embodiment, the through hole 21 is formed in the electromagnetic steel sheet 100 at once in the axial hole forming step. However, in the axial hole forming step, the through holes may be formed by punching the electromagnetic steel sheet 100 multiple times.

In the above embodiment, the rotor core 1 has two key portions 12 on the inner surface of the shaft hole 11 . However, the rotor core may have one or three or more key portions on the inner surface of the shaft hole. In the above embodiment, the key portion 12 has a rectangular shape when the rotor core 1 is viewed in the axial direction. However, the key portion may have a shape other than the rectangular shape when the rotor core is viewed in the axial direction. In the above-described embodiment, the two key portions 12 are located on the inner surface of the shaft hole 11 and at opposing positions. However, the plurality of key portions may be positioned on the inner surface of the shaft hole at non-opposing positions.

The present invention has a shaft hole penetrating in the axial direction and a key portion protruding radially inward on the inner periphery of the shaft hole, and rotates a plurality of plate-like rotor core members in the circumferential direction to increase the thickness of the rotor core member. It can be applied to a method of manufacturing a rotor core configured by laminating in a direction.

1 rotor core 11 shaft hole 12 key portion 20 rotor core member 21 through hole 22 projecting portion 100 electromagnetic steel plate 101 first through hole 102 first slit 103 second slit 104 convex portion 111 second through hole 200 rotor core manufacturing apparatus 210 first through hole Forming portion 211 First fixed mold 212 First movable mold 213 First punch 220 Second through hole forming portion 221 Second fixed mold 222 Second movable mold 223 Second punch 225 Punch drive mechanism 226 Slide member 226a Concave portion 227 drive portion 227a actuator 227b drive connection portion 228 cam 229 support portion 229a through hole 230 shaft hole forming portion 231 third fixed mold 232 third movable mold 233 third punch 240 outline punching portion 241 fourth fixed mold 242 4 movable mold 243 fourth punch

Claims (8)

A plurality of plate-shaped rotor core members having a shaft hole penetrating in the axial direction and a key portion protruding radially inward on the inner circumference of the shaft hole are laminated in the thickness direction while being rotated in the circumferential direction. A rotor core manufacturing method comprising:
a first through-hole forming step of punching out first through-holes respectively forming contours of a plurality of convex portions including the convex portion constituting the key portion in a plate;
a second through-hole forming step of forming a second through-hole by cutting a part of the plurality of protrusions;
A shaft for forming a through hole that constitutes a part of the shaft hole by punching a region that at least partially overlaps with the first through hole and the second through hole in plan view of the plate material. a hole forming step;
having
Rotor core manufacturing method. In the rotor core manufacturing method according to claim 1,
In the shaft hole forming step, a punch and a die having recesses that are recessed along the shape of the protrusions that are not cut off in the second through hole forming step are used to form the through holes in the plate material. forming pores,
Rotor core manufacturing method. In the rotor core manufacturing method according to claim 1 or 2,
an outer shape punching step of punching a plate having the through hole formed therein with the outer shape of the rotor core member to form the rotor core member;
a rotor core member laminating step for obtaining the rotor core by laminating the rotor core member in the thickness direction while rotating the rotor core member in the circumferential direction;
further having
Rotor core manufacturing method. In the rotor core manufacturing method according to claim 3,
In the second through-hole forming step, each time the plate material is punched out a predetermined number of times,
changing the position of the protrusion to be cut out of the plurality of protrusions;
Rotor core manufacturing method. In the rotor core manufacturing method according to claim 4,
In the first through-hole forming step, as the plurality of protrusions, four protrusions are formed on the plate material at equal intervals in the circumferential direction,
The second through-hole forming step includes:
a first projection cutting step of cutting a pair of radially opposed projections out of the four projections;
a second protrusion cutting step of cutting off another pair of protrusions of the four protrusions that face each other in the radial direction;
including
In the rotor core member lamination step, the rotor core member from which the pair of protrusions have been removed is laminated in the thickness direction while being rotated 90 degrees in the circumferential direction with respect to the rotor core member from which the pair of protrusions have been removed. do,
Rotor core manufacturing method. A plurality of plate-shaped rotor core members having a shaft hole penetrating in the axial direction and a key portion protruding radially inward on the inner circumference of the shaft hole are laminated in the thickness direction while being rotated in the circumferential direction. A rotor core manufacturing apparatus for manufacturing a rotor core constituted by
a first through-hole forming part for punching out first through-holes forming contours of a plurality of projections constituting the key part in a plate material;
a second through-hole forming portion that forms a second through-hole by cutting out a portion of the plurality of convex portions;
A shaft for forming a through hole that constitutes a part of the shaft hole by punching a region that at least partially overlaps with the first through hole and the second through hole in plan view of the plate material. a pore-forming portion;
having
Rotor core manufacturing equipment. In the rotor core manufacturing apparatus according to claim 6,
The second through hole forming part is
a plurality of punches for respectively cutting the plurality of protrusions;
a punch drive mechanism for positioning the punching direction positions of the plurality of punches at a punching position and a non-punching position;
has
The punch driving mechanism is
When some of the plurality of punches are positioned at the punching position, the remaining punches of the plurality of punches are positioned at the non-punching position,
positioning the some punches at the non-punching position when the remaining punches are positioned at the punching position;
Rotor core manufacturing equipment. In the rotor core manufacturing apparatus according to claim 7,
The punch driving mechanism is
a slide member, which is a plate-like member extending in the longitudinal direction, and moves the plurality of punches between the punching position and the non-punching position by moving in the longitudinal direction;
a drive unit that moves the slide member in the longitudinal direction;
A rotor core manufacturing apparatus.

Images