JP7371514B2 - Motor core manufacturing method - Google Patents

Description

The present disclosure relates to a method of manufacturing a motor core.

The motor manufacturing line disclosed in Patent Document 1 includes a press device, a stator assembly device, a common carry-out path, and a laser marking section. The press device forms a stator core by performing pressing multiple times while feeding a long steel plate. The stator assembly device assembles the stator by subjecting the stator core to multiple manufacturing processes. The common unloading path carries out the assembled stator. The laser marking section is provided near the common discharge path, and prints on the completed stator using a laser. For example, the laser engraving unit prints necessary information in order to improve traceability of press processing and the like.

As motor cores become smaller, the space for printing is becoming smaller, and there is a need for highly accurate and high-speed printing. Generally, the position of printing on the motor core is determined, and the laser is irradiated from above or below the motor core in the axial direction. For example, the laser is irradiated from above or below the motor core in the axial direction.

International Publication No. 2004/95676

With the method of irradiating the laser from the underside of the motor core, it is easier to align the motor core according to the focal length of the laser engraving part, but the laser engraving part becomes dirty due to dust falling from the motor core, which obstructs laser irradiation. There is a risk of being exposed. On the other hand, in the method of irradiating the laser from above the motor core, the distance between the laser marking part and the motor core changes due to the difference in the thickness of the motor core, which may result in poor printing accuracy. In such a case, it becomes necessary to move the motor core or the laser marking part to perform appropriate alignment. Therefore, there is a need for a technology that can perform laser irradiation well and print with high precision.

An object of the present disclosure is to provide a method for manufacturing a motor core in which laser irradiation is performed well and printing can be performed with high precision in a process of printing by irradiating laser light onto a motor core made of a plurality of laminated electromagnetic steel sheets. It is said that

A method for manufacturing a motor core according to the present disclosure is a method for manufacturing a motor core in which a laser beam is irradiated from a laser marker to print on a motor core made of a plurality of laminated electromagnetic steel sheets, and the motor core is raised until the upper surface of the motor core contacts a stopper. , vertically aligning the upper surface of the motor core with respect to the laser marker, and irradiating laser light from the laser marker to print on the upper surface of the motor core.

According to the present disclosure, there is provided a method for manufacturing a motor core in which laser irradiation is performed well and printing can be performed with high accuracy in a step of printing by irradiating laser light onto a motor core made of a plurality of laminated electromagnetic steel sheets. Can be done.

FIG. 1 is a plan view schematically showing a stator core in Embodiment 1. FIG. 2 is a plan view schematically showing the rotor core in the first embodiment. FIG. 3 is a sectional view taken along the line II-II in FIG. FIG. 4 is an explanatory diagram illustrating a state in which a block stack is being placed on a pallet. FIG. 5 is an explanatory diagram illustrating a state in which the block stack is placed on a pallet. FIG. 6 is a plan view illustrating a state in which the pallet has been positioned in the horizontal direction. FIG. 7 is an explanatory diagram illustrating a state in which a pallet on which a block stack is placed is arranged between a lifting device and an upper stopper. FIG. 8 is an explanatory diagram illustrating a state in which the block laminate is assembled to the upper stopper. FIG. 9 is a side sectional view illustrating the laser beam irradiation range that can print on the upper surface of the block laminate. FIG. 10 is a plan view illustrating the laser beam irradiation range that can print on the upper surface of the block laminate. FIG. 11 is a plan view illustrating the laser beam irradiation range that can print with the same degree of accuracy on the upper surface of the block stack.

<Embodiment 1>
In this embodiment, the present invention is applied to manufacturing the stator core 10 and rotor core 20 shown in FIGS. 1 and 2. Stator core 10 is an example of a motor core, and rotor core 20 is another example of a motor core.

The stator core 10 shown in FIG. 1 is made of a laminate in which a plurality of electromagnetic steel plates 11 are stacked. The stator core 10 has a generally annular shape as a whole. In the stator core 10, a plurality of block cores 32 are stacked and welded together. Each of the plurality of block cores 32 includes a plurality of electromagnetic steel plates 11 stacked together and assembled together.

Stator core 10 has a slot portion 12 and a fastening portion 13. The slot portions 12 are provided at equal intervals along the inner circumference of the stator core 10, and are recessed from the inside to the outside in the radial direction. The slot portion 12 is provided with a coil (not shown). The fastening portion 13 is provided on the outer periphery of the stator core 10 so as to protrude radially outward. Three fastening portions 13 are provided at equal intervals along the outer periphery of stator core 10 . The fastening portion 13 has a fastening hole 14 passing through the stator core 10.

As shown in FIGS. 2 and 3, the rotor core 20 includes a rotor core body 30 made of a laminate in which a plurality of electromagnetic steel plates 31 are laminated. End plates 21, 21 are welded to both sides of the rotor core body 30 in the stacking direction. The rotor core body 30 as a whole has a cylindrical shape with an outer diameter smaller than the inner diameter of the stator core 10. The rotor core body 30 includes a plurality of block cores 32 stacked together and welded together. Each of the plurality of block cores 32 includes a plurality of electromagnetic steel plates 31 stacked together and assembled together.

The rotor core body 30 has a shaft hole 33 and a magnet hole 34. The shaft hole 33 is provided to penetrate through the center of the rotor core body 30. The shaft 23 is inserted into the shaft hole 33. As shown in FIG. 2, a plurality of magnet holes 34 are provided around the shaft hole 33. A magnet material 26 is sealed in each of the plurality of magnet holes 34 . The magnet material 26 is made of a square columnar permanent magnet.

The shaft 23 has a cylindrical shape and constitutes a rotation center axis of the rotor core 20. A shaft-side refrigerant flow path 24 through which a refrigerant such as cooling oil flows is formed inside the shaft 23 . A plurality of openings 25 for shaft-side coolant flow paths 24 are formed on the outer peripheral surface of the shaft 23 at intervals in the circumferential direction (see FIG. 3). The opening 25 is a supply port for supplying cooling oil from the shaft-side coolant flow path 24 to the rotor core body 30.

As shown in FIG. 3, a refrigerant flow path 35 through which a refrigerant flows is formed inside the rotor core 20. As shown in FIG. The coolant flow path 35 has an inner opening 36 formed on the inner peripheral surface of the shaft hole 33 and outer openings 37 , 37 formed on both bottom surfaces of the rotor core 20 . The inner opening 36 is an inlet that communicates with the opening 25 of the shaft 23 and introduces the refrigerant into the rotor core 20 . The outer openings 37 , 37 are discharge ports that open toward the outside of the rotor core 20 and discharge the refrigerant from the inside of the rotor core 20 . The coolant flow path 35 is formed by stacking electromagnetic steel sheets 31 having holes of different shapes when viewed from above.

Next, a printing device 50 used in a method of manufacturing a rotor core 20 and a method of manufacturing a stator core 10, which will be described later, will be described. The printing device 50 is a device that prints characters, symbols, figures, etc. on the rotor core 20 and stator core 10 by processing them using laser light. The printing device 50 prints, for example, a two-dimensional information code including manufacturing information such as a press process. As shown in FIG. 9, the printing device 50 includes a laser marker 51, a pallet 52, an elevating section 53, an upper stopper 54, and a control device (not shown).

The laser marker 51 is a device that irradiates laser light. The laser marker 51 includes a laser oscillator, a galvano scanner, a condensing lens, a controller, etc. (not shown). A laser oscillator oscillates laser light by amplifying light emitted by irradiating a laser medium with excitation light using a resonator. A galvano scanner uses one or more mirrors to scan laser light. A condensing lens condenses laser light into a high energy density at a focal length. The controller controls the oscillator and galvano scanner so that printing is performed based on print data input via an input interface (such as a keyboard) or external communication. As shown in FIG. 9, the laser marker 51 is provided with an irradiation section 51A having an irradiation port opening downward.

The pallet 52 is a jig on which the rotor core 20 is placed. As shown in FIG. 4, the pallet 52 includes a mounting section 52A and a post section 52B. The mounting portion 52A is configured in the shape of a square plate, and has a mounting surface on which the rotor core 20 is mounted on the upper surface. The post section 52B has a cylindrical shape and projects upward from the mounting surface of the mounting section 52A. The post portion 52B is inserted into the shaft hole 33 of the rotor core 20. A pair of positioning pins 52C that protrude upward are provided at the upper end of the post portion 52B.

The lifting unit 53 is a lifting device that lifts and lowers the pallet 52. As shown in FIG. 7, the elevating portion 53 includes a base plate portion 53A and four pushing-up portions 53B (see FIG. 6). Note that in FIGS. 7 to 10, only two push-up portions 53B are shown. The base plate portion 53A is formed with four through holes 53C that penetrate in the thickness direction. The four through holes 53C are provided in the same circular shape at equal angular intervals. The four push-up parts 53B are inserted into the through holes 53C and push up the pallet 52 placed on the base plate part 53A from below. The elevating portion 53 operates based on a control signal from a control device (not shown), and uses, for example, the driving force of a motor to move the four elevating portions 53B up and down, thereby elevating the pallet 52.

The upper stopper 54 is configured in a plate shape, and has a recessed portion 54A recessed upward on the lower surface. As shown in FIG. 8, the recessed portion 54A is slightly larger in the horizontal direction than the rotor core 20. The upper stopper 54 has a pair of positioning holes 54B formed slightly outside the center of the plate surface and located at symmetrical positions with respect to the center of the plate surface. When positioning the rotor core 20, the positioning pin 52C of the pallet 52 is inserted into the positioning hole 54B. The upper stopper 54 has a pair of printing holes 54C formed outside the pair of positioning holes 54B. The printing hole 54C has a shape extending in an arc shape around the center of the plate surface of the upper stopper 54. The upper stopper 54 is provided vertically above the pallet 52 and comes into contact with the upper surface of the rotor core 20 raised by the lifting section 53 to define the position of the upper surface of the rotor core 20 with respect to the laser marker 51. The distance between the upper stopper 54 and the laser marker 51 satisfies a desired printing condition (such that the rotor core 20 is at the focal length of the laser marker 51) when the rotor core 20 is positioned as described later. It is fixed in such a position.

Next, a method for manufacturing the rotor core 20 and a method for manufacturing the stator core 10 will be described. The rotor core 20 and the stator core 10 are manufactured on a production line equipped with devices (not shown) such as a roll feeder, a press device, a welding device, and a control device in addition to the printing device 50 described above. Various devices such as a roll feeder, a press device, a welding device, etc. are controlled by a control device. The control device includes a CPU that performs arithmetic processing according to a program, a memory such as a ROM that stores various operating programs such as a manufacturing program, and a RAM that has a work area.

The method for manufacturing the rotor core 20 includes a sending step of sending out a plate-shaped base material, a block forming step of forming the block core 32, and a laminate forming step of forming the block laminate 38. The method for manufacturing stator core 10 includes a sending step similar to the method for manufacturing rotor core 20, a block forming step, and a laminate forming step. The manufacturing method of the rotor core 20 includes a printing step of printing on the block laminate 38, a sealing step of sealing the magnet material 26 to the block laminate 38, and an end plate 21 attached to the block laminate 38 sealed with the magnet material 26. , 21, and the like. In the following description, a method for manufacturing the rotor core 20 will be described as an example of a method for manufacturing the motor core.

In the delivery process, a roll feeder is used to send out a plate-shaped base material. In the block forming process, a plurality of electromagnetic steel plates 31 are punched out from the sent-out base material using a press device. The control device synchronizes the pitch at which the roll feeder feeds the base material and the timing at which the press device punches the base material. In this way, a plurality of electromagnetic steel sheets 31 are punched out in order from the sent-out base material. In the block forming process, a plurality of electromagnetic steel sheets 31 are laminated. As a result, a block core 32 in which a plurality of electromagnetic steel sheets 31 are laminated is formed. The block core 32 is formed by stacking a plurality of electromagnetic steel sheets 31 punched out as the base material is sent out in the order in which they were punched out. Each of the plurality of electromagnetic steel sheets 31 constituting one block core 32 is provided with a joint portion (not shown) that protrudes in one direction in the stacking direction by so-called dowel processing. The electromagnetic steel plates 31 that are adjacent to each other are connected to each other by caulking the connection parts due to the uneven relationship. Further, at one end of the block core 32 in the stacking direction, an electromagnetic steel plate 31 having no coupling portion is disposed. Therefore, the electromagnetic steel plate 31 on one end side of the block core 32 is not coupled to the electromagnetic steel plate 31 adjacent to its one end side. The press device is controlled by a control device to punch out a predetermined number of electromagnetic steel sheets 31 that do not have a joint, thereby forming block cores 32 stacked at a predetermined height.

In the laminate forming step, a plurality of block cores 32 are stacked in a predetermined direction. In the laminate forming step, for example, block cores 32 for the first to sixth stages are stacked (see FIG. 3) to form a block laminate 38. When stacking the block cores 32, in order to improve the dimensional accuracy of the stacking height of the rotor core body 30, the block cores 32 may be rotated by a predetermined angle and stacked, so-called roll stacking.

In the printing process, first, as shown in FIG. 5, the block stack 38 is assembled on the pallet 52. As shown in FIGS. 4 and 5, the block stack 38 is placed on the upper surface of the mounting section 52A of the pallet 52 by inserting the post portion 52B of the pallet 52 into the shaft hole 33 of the block stack 38. do. When the block stack 38 is assembled to the pallet 52, a pair of positioning pins 52C protrudes upward from the shaft hole 33 of the block stack 38.

Subsequently, the pallet 52 with the block stack 38 assembled thereon is placed on the elevating section 53 and positioned in the horizontal direction. Specifically, the pallet 52 placed on the lifting section 53 is moved in the direction of the outlined arrow, as shown in FIG. Then, orthogonal edges (adjacent sides) 52D, 52E of the pallet 52 are brought into contact with side stoppers 55, 56 that restrict movement. In this state, as shown in FIG. 7, the pallet 52 with the block stack 38 assembled is placed vertically below the upper stopper 54. Note that illustration of the side stoppers 55 and 56 is omitted in FIGS. 7 to 10.

Subsequently, the elevating section 53 is operated to raise the four push-up sections 53B until the upper surface of the block stack 38 comes into contact with the upper stopper 54, as shown in FIG. Thereby, the upper surface of the block stack 38 can be aligned with respect to the laser marker 51 in the vertical direction. At this time, the upper end of the block stack 38 enters the recess 54A of the upper stopper 54. This aligns the block stack 38 with respect to the upper stopper 54 in the horizontal direction. Furthermore, as shown in FIG. 8, the positioning pin 52C of the pallet 52 is inserted into the positioning hole 54B of the upper stopper 54. The horizontal clearance between the positioning pin 52C and the positioning hole 54B is smaller than the horizontal clearance between the upper end of the block stack 38 and the recess 54A, and the positioning pin 52C cannot be inserted into the positioning hole 54B. This enables more accurate horizontal positioning. As described above, by performing the step of aligning the block stack 38 in the horizontal direction, the laser marker 51 is positioned above the axis of the block stack 38.

Next, a step of printing on the upper surface of the block laminate 38 by irradiating laser light from the laser marker 51 is performed. For example, as shown by the arrow shown in FIG. 9, laser light is irradiated from the laser marker 51 so that the laser light hits the upper surface of the block laminate 38 through the printing hole 54C of the upper stopper 54. Thereby, a two-dimensional information code, etc. including manufacturing information such as a pressing process can be printed on the upper surface of the block laminate 38. Here, as shown in FIG. 10, the laser marker 51 is located vertically above the axis of the block stack 38. Therefore, the printable range AR1 by the laser beam irradiated from the laser marker 51 extends to a circular area centered on the axis on the upper surface of the block laminate 38. In the printable range AR1, at a plurality of different positions within an annular (doughnut-shaped) area AR2 (see FIG. 11) centered on the axis of the block stack 38, the focal length of the laser marker 51 is not adjusted. , laser irradiation can be performed with the same focal length. Therefore, even when changing the printing position due to reprinting or the like, highly accurate printing can be performed.

The lower surface (irradiation surface) of the irradiation section 51A of the laser marker 51 is located vertically above the shaft hole 33. That is, the lower surface (irradiation surface) of the irradiation part 51A of the laser marker 51 is not located vertically above the upper surface of the block laminate 38. Therefore, when the upper surface of the block laminate 38 is irradiated with a laser beam, it becomes difficult for steam generated by the laser irradiation to directly hit the laser marker 51 . As a result, the laser marker 51 becomes less likely to become dirty, and a good irradiation state can be maintained.

Although the method for manufacturing the rotor core 20 has been described above, the method for manufacturing the stator core 10 is performed in the same manner. In the case of the method for manufacturing the stator core 10, the block stack may be directly raised and lowered by the lifting section 53 without using the pallet 52.

Next, the effects of this embodiment will be explained. In the method for manufacturing a motor core of the present disclosure, the upper surface of the motor core is vertically aligned with the laser marker by raising the upper surface of the motor core until it contacts the stopper, so that the distance between the laser marker and the upper surface of the motor core is constant. This makes it easier to align the upper surface of the motor core to a position corresponding to the focal length of the laser marker. Therefore, it is possible to print with high accuracy on the upper surface of the motor core by irradiating laser from the laser marker. Furthermore, since the laser marker is located vertically above the upper surface of the motor core, even if a foreign object or the like is generated on the upper surface of the motor core during laser irradiation, it will not fall toward the laser marker. Therefore, problems such as the laser marker becoming dirty are less likely to occur, and laser irradiation is not obstructed. Therefore, in the step of printing by irradiating the upper surface of the motor core with a laser beam, laser irradiation can be performed well and printing can be performed with high precision.

In the motor core manufacturing method of the present disclosure, the motor core is horizontally aligned with respect to the laser marker. Therefore, it becomes easier to align the portion of the upper surface of the motor core where printing is performed to a position corresponding to the focal length of the laser marker. Therefore, by irradiating laser from the laser marker, it is possible to accurately print at a desired position on the upper surface of the motor core.

In the motor core manufacturing method of the present disclosure, a laser marker is positioned above the axis of the motor core. Therefore, on the upper surface of the motor core, positions symmetrical about the axis can maintain the same distance from the laser marker. Thereby, a plurality of positions on the upper surface of the motor core can be aligned with positions corresponding to the focal length of the laser marker, and printing can be performed with high precision at a plurality of positions on the upper surface of the motor core.

<Other embodiments>
The present invention is not limited to the embodiments described above and illustrated in the drawings; for example, the following embodiments are also included within the technical scope of the present invention.
(1) In addition to the embodiments described above, the delivery process, block forming process, and laminate forming process can be modified as appropriate. For example, in the laminate forming process, the number of stages in which a plurality of blocks are stacked can be changed as appropriate. The press device may be configured to simultaneously punch out a plurality of base materials stacked in the thickness direction.
(2) In addition to the embodiments described above, the configurations of the rotor core and stator core can be modified as appropriate. For example, the number of stages in which a plurality of blocks are stacked to form a block laminate is not limited to six stages, but may be an integer of two or more stages. Furthermore, the technology of the present disclosure is also effective for rotor cores and stator cores that do not have refrigerant flow paths inside.

10...Stator core (motor core)
11...Electromagnetic steel plate 20...Rotor core (motor core)
31...Electromagnetic steel plate 38...Block laminate 50...Printing device 51...Laser marker 54...Upper stopper (stopper)

Claims (2)

A method for manufacturing a motor core in which a laser marker is irradiated with a laser beam to print on a motor core made of a plurality of laminated electromagnetic steel sheets, the method comprising:
raising the upper surface of the motor core until it contacts a stopper, vertically aligning the upper surface of the motor core with respect to the laser marker;
positioning the laser marker vertically above the axis of the motor core so that a printable range by laser light emitted from the laser marker spreads to a circular area centered on the axis of the motor core on the upper surface of the motor core;
A method for manufacturing a motor core, comprising irradiating laser light from the laser marker to print on the upper surface of the motor core. The method for manufacturing a motor core according to claim 1, further comprising aligning the motor core in a horizontal direction with respect to the laser marker.

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