JP7726180B2 - Manufacturing equipment for laminated steel sheets for motors - Google Patents

Description

This disclosure relates to a manufacturing apparatus for laminated steel sheets for motors.

Patent Document 1 discloses a manufacturing device that cuts out core plates, stacks multiple core plates, heats and softens adhesive, applies the softened adhesive to the edges of the stacked core plates, presses the multiple core plates together, and then hardens the resin to produce laminated steel plates.

JP 2015-519721 A

Motors are constantly being required to be small, lightweight, and highly efficient. To improve efficiency, it is important to reduce magnetic loss in motors, and methods of reducing loss using laminated steel plates are being adopted. However, this requires a smaller magnetic gap and higher precision in the shape, and it is difficult to precisely fix the steel plates using welding methods that join multiple steel plates together.

Furthermore, for productivity reasons, split-core motor structures are used, but splitting the core requires high precision in the mating surfaces. Therefore, for the same reasons as above, high precision is difficult to achieve.

Meanwhile, Patent Document 1 discloses a method for manufacturing laminated steel plates in which adhesive is applied to one edge of multiple core plates, the core plates are pressed using a mold, and then the adhesive is cured. However, unlike resin molding, manufacturing methods using adhesives raise concerns that mold releasability may be impaired. Furthermore, if adhesive is impregnated between the stacked core plates to strengthen the fixation of multiple core plates, the thickness of the adhesive reduces the metal density of the laminated steel plates, resulting in magnetic loss in the motor.

In addition, because adhesives tend to expand during the curing process, there is also the problem of burrs forming at the edges of the laminated steel sheets due to the adhesive overflowing.

This disclosure has been made to solve these problems, and aims to provide a manufacturing device for laminated steel sheets for motors that suppresses the formation of adhesive burrs and forms them into highly accurate shapes.

The manufacturing apparatus for laminated steel sheets for motors according to the present disclosure comprises a storage section with an opening that stores multiple stacked core plates, a pressing section that presses the multiple core plates, and a sheet between the pressing section and the storage section, wherein the pressing section has an elastic body with a surface smaller than the upper surface of the opening of the storage section, and the elastic body presses the multiple core plates via the sheet. This makes it possible to provide a manufacturing apparatus for laminated steel sheets for motors that suppresses the occurrence of adhesive burrs and forms them into highly accurate shapes.

The sheet may have a water-repellent surface. This configuration makes it easier to efficiently remove adhesive burrs.

The sheet may have a portion that is larger than the contact area between the elastic body and the multiple core plates and extends outward beyond the opening, and this extending portion may be configured to tilt in the direction of gravity at least when the multiple core plates are pressed by the pressing portion. This configuration makes it easier to efficiently remove adhesive flash.

This disclosure makes it possible to provide a manufacturing device for laminated steel sheets for motors that suppresses the occurrence of adhesive burrs and forms them into highly accurate shapes.

1 is a schematic diagram of a laminated steel sheet for motors according to the present disclosure and a manufacturing apparatus for the laminated steel sheet for motors. 3A to 3C are diagrams illustrating a manufacturing process of a laminated steel sheet for a motor according to the present disclosure and a mechanism for removing adhesive burrs. 10A and 10B are diagrams illustrating the generation of burrs due to misalignment between a core plate and a pressing portion according to the present disclosure. 10 is a diagram illustrating the generation of burrs when the sheet is not used in the manufacturing apparatus for laminated steel sheets for motors according to the present disclosure. FIG.

Embodiments of the present disclosure will now be described with reference to the drawings. Figure 1 shows the configuration of a laminated steel sheet for motors and a manufacturing apparatus for the laminated steel sheet for motors according to this embodiment.

The manufacturing apparatus 100 for laminated steel sheets for motors shown in Figure 1 includes a storage section 101 and a pressing section 102.

The storage section 101 has an opening in which multiple stacked core plates 110 are accommodated. Between the storage section 101 and the pressing section 102 is a sheet 103 with a water-repellent surface. The pressing section 102 also has a heat-resistant elastic body 104.

The core plate 110 has a pressure surface 111, a molding reference surface 112, and a side surface 113. The core plate 110 is accommodated so that the molding reference surface 112 faces the bottom surface of the opening. The elastic body 104 has a surface that is smaller than the opening surface of the accommodation section 101. Adhesive 105 is filled between the side surface of the core plate 110 and the accommodation section 101. The elastic body 104 also presses against the pressure surface 111 of the core plate 110 via the sheet 103 (see the lower right diagram in Figure 1).

The manufacturing apparatus 100 shown in FIG. 1 has a structure that provides an elastic body 104, which makes it possible to absorb shape differences between the core plate 110 and the pressure surface 111 or molding reference surface 112 of the molding die (inside the accommodating section 101). In this way, the creation of a space between the core plate 110 and the molding die is prevented, thereby suppressing the occurrence of adhesive burrs and improving shape accuracy. The elastic body 104 may be provided between the bottom surface of the accommodating section 101 and the molding reference surface 112, and the position of the elastic body 104 is not particularly limited as long as the purpose of preventing such shape differences is achieved.

The elastic body 104 is preferably a heat-resistant silicone sheet or silicone rubber. A thickness of approximately 2 mm for the elastic body 104 is sufficient to absorb the shape difference, but there is no particular limitation.

It is preferable that the sheet 103 has the ability to conform to the shape of the core plate 110, is strong enough to prevent breakage due to deformation, and is releasable when removed after pressing. Examples of materials for the sheet 103 include fluororesins such as PTFE (polytetrafluoroethylene).

Furthermore, the pressurized surface 111 of the core plate 110 may have fractures caused by pressing or lasers. These fractures on the pressurized surface 111 may bite into the elastic body 104 when pressed, resulting in poor demolding. This may cause the manufactured laminated steel sheet to become distorted when demolded.

If the elastic body 104 were to come into direct contact with a fractured area on the pressure surface 111, the fractured area could bite into the elastic body, further worsening mold releasability. Therefore, by sandwiching the sheet 103 between the pressure surface 111 and the elastic body 104, the sheet 103 deforms to conform to the shape of the part, preventing the fractured area from biting into it. Therefore, by providing the sheet 103, mold releasability can be ensured.

The storage section 101 is not completely sealed, but has an opening in one area, leaving the space open. Furthermore, the sheet 103 has a portion that is larger than the contact area of the core plate 110 and extends outward beyond the opening. This extending portion is designed to tilt in the direction of gravity at least when the multiple core plates are pressed by the pressing section.

The extending portion may be configured to tilt in the direction of gravity even when not being pressed. This configuration will achieve the effects described below at least within the temperature range in which the adhesive 105 is heated to soften it and then harden it.

Next, using Figure 2, which is an enlarged view of the dashed line portion shown in the lower right diagram of Figure 1, we will explain the manufacturing process for laminated steel sheets for motors according to this embodiment and the mechanism for removing adhesive burrs. For convenience, the five figures shown in Figure 2 will be referred to as Figure 1, Figure 2, Figure 3, Figure 4, and Figure 5 from left to right.

As shown in Figure 1 of Figure 2, the core plate 110 is placed in the storage section 101 at room temperature and filled with adhesive 105. Next, as shown in Figure 2, the adhesive 105 is heated to soften it and filled between the storage section 101 and the core plate 110. As the curing reaction of the adhesive 105 progresses, the adhesive 105 expands and protrudes above the storage section 101. As shown in Figure 3, taking advantage of the water-repellent properties of the sheet 103, i.e., the small contact angle between the sheet 103 and the adhesive 105, the hardened adhesive 105 forms burrs 120 and separates from the top of the storage section 101. Then, as shown in Figure 4, due to the water-repellent properties of the sheet 103, the burrs 120 move from the core plate 110 to the extended portion of the sheet 103 and are expelled. Finally, as shown in Figure 5, the core plate 110 is removed from the storage section 101, and a core plate 110 with reduced adhesive burrs 105 is obtained.

In this way, it is possible to prevent burrs 120 from the adhesive 105 from remaining on the core plate 110.

Next, using Figure 3, we will explain the occurrence of burrs due to misalignment between the core plate 110, particularly the top surface, and the pressing portion 102.

Because the pressing portion 102 slides, it cannot perfectly match the shape of the upper surface of the core plate 110, leaving a gap 121 when pressed. The adhesive 105 seeps into this gap 121, causing burrs to form, which leads to a decrease in productivity and shape accuracy due to burr removal. The manufacturing apparatus 100 for laminated steel sheets for motors according to this embodiment is able to suppress the formation of such burrs by providing an elastic body 104 and a sheet 103 between the core plate 110 and the pressing portion 102.

Figure 4 is a diagram explaining the occurrence of burrs when the sheet is not used in the manufacturing apparatus for laminated steel sheets for motors according to this embodiment. For convenience, the four figures shown in Figure 4 are referred to as Figure 1, Figure 2, Figure 3, and Figure 4 from left to right. Furthermore, explanations of parts that are repeated from Figure 2 may be omitted.

As shown in Figure 1 of Figure 4, the core plate 110 is placed in the storage section 101 at room temperature and filled with adhesive 105. The sheet 103 does not have any portion extending beyond the opening. Next, the adhesive 105 is heated and softened. As the curing reaction progresses, the adhesive 105 expands and protrudes above the storage section 101 (see Figure 2). Because the sheet 103 does not have any such extending portion, the expanded adhesive 105 hardens with a portion in contact with the storage section 101 (see Figure 3). As a result, as shown in Figure 4, when the core plate 110 is removed from the storage section 101, burrs 120 of the adhesive 105 remain.

In this way, by using the manufacturing apparatus disclosed herein, it is possible to suppress the occurrence of adhesive burrs and obtain laminated steel sheets for motors that are formed into highly precise shapes.

Note that this disclosure is not limited to the above-described embodiments and can be modified as appropriate without departing from the spirit of the disclosure.

REFERENCE SIGNS LIST 100 Manufacturing apparatus for laminated steel sheets for motors 101 Storage section 102 Pressing section 103 Sheet 104 Elastic body 105 Adhesive 110 Multiple core plates 111 Pressing surface 112 Forming reference surface 113 Side surface 120 Burr 121 Gap

Claims (3)

a housing portion having an opening for housing a plurality of stacked core plates;
a pressing portion that presses the plurality of core plates;
a sheet between the pressing portion and the storage portion,
The pressing portion includes an elastic body, and presses the plurality of core plates by the elastic body via the sheet ,
the sheet has a portion that is larger than the contact area between the elastic body and the plurality of core plates and that extends outward beyond the openings,
The extending portion is structured to tilt in the direction of gravity at least when the plurality of core plates are pressed by the pressing portion.
Manufacturing equipment for laminated steel sheets for motors. The manufacturing apparatus for laminated steel sheets for motors according to claim 1 , wherein the sheet has a water-repellent surface. The elastic body has a surface that is smaller than the upper surface of the opening of the accommodating portion.
The manufacturing apparatus for laminated steel sheets for motors according to claim 1.