Structure and method for manufacturing the same

Abstract

To efficiently manufacture electrically efficient structures. [Solution] In order to create a structure (stator 1) made by laminating a steel plate and an amorphous sheet, the following steps are performed: punching step A1 to obtain a steel sheet-like member 2 and an amorphous sheet-like member 3 having predetermined shapes by punching out the steel plate and the amorphous sheet-like member; coating step A2 to apply fluororubber to the steel sheet-like member 2 and / or amorphous sheet-like member 3; lamination step A3 to create a pre-heating structure by laminating the fluororubber-coated steel sheet-like member 2 and amorphous sheet-like member 3; and heating step A4 to heat and pressurize the pre-heating structure to vulcanize the fluororubber and form an adhesive layer 4.

Description

Technical Field

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[0001] The present invention relates to a structure and a method for manufacturing the same, and more particularly to a structure in which a steel sheet-like member punched into a predetermined shape and an amorphous sheet-like member punched into a predetermined shape are laminated, and a method for manufacturing the same.

Background Art

[0002] Conventionally, for motor parts such as rotors and stators that constitute a motor, a structure in which a steel sheet-like member obtained by punching a steel plate into a predetermined shape and an amorphous sheet-like member obtained by punching an amorphous thin plate into a predetermined shape are laminated has been used to reduce iron loss. In such a structure, methods such as caulking and welding are known for laminating the steel sheet-like member and the amorphous sheet-like member. However, since the rotors and stators laminated by these methods have high iron loss, a structure in which the steel sheet-like member and the amorphous sheet-like member are adhered with a thermosetting adhesive is also known (Patent Document 1). In Patent Document 1, in order to manufacture the above structure, a step of applying an adhesive to the steel plate and the amorphous thin plate before punching (Step a), a step of laminating them (Step b), a step of thermally curing the adhesive by hot pressing (Step c), a step of punching the obtained laminate into the shape of a rotor or a stator (Step d), a step of heating and annealing the punched laminate (Step e), and a step of laminating these laminates to obtain the above rotor or stator (Steps f and g) are performed (see FIG. 2).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

[0005] In other words, the structure according to claim 1 is a structure in which a steel sheet-like member obtained by punching a steel plate into a predetermined shape and an amorphous sheet-like member obtained by punching an amorphous thin plate into a predetermined shape are laminated together, This invention is characterized by the formation of an adhesive layer made of fluororubber between the steel sheet-like member and the amorphous sheet-like member. Furthermore, the method for manufacturing a structure according to claim 2 is characterized by a punching step of punching out steel plates and amorphous sheets to obtain steel sheet-like members and amorphous sheet-like members having predetermined shapes, respectively; a coating step of applying fluororubber to the steel sheet-like members and / or amorphous sheet-like members; a lamination step of laminating the fluororubber-coated steel sheet-like members and amorphous sheet-like members to create a pre-heated structure; and a heating step of heating and pressurizing the pre-heated structure to vulcanize the fluororubber to form an adhesive layer and anneal the steel sheet-like members, thereby creating a structure made by laminating steel plates and amorphous sheets. [Effects of the Invention]

[0006] According to the invention of claim 1 above, by bonding the steel sheet-like member and the amorphous sheet-like member with fluororubber, cracks caused by vibration are prevented, and high electrical efficiency can be maintained over a long period of time, compared to the case in which an adhesive made of thermosetting resin is used as in Patent Document 1. Furthermore, according to the invention of claim 2, a steel sheet-like member and an amorphous sheet-like member having a predetermined shape are obtained in the punching process, and then fluororubber is applied to them to form an adhesive layer, so that the adhesive layer is not damaged during punching as in Patent Document 1. Furthermore, in the heating process, the pre-heating structure is heated and pressurized to vulcanize the fluororubber, and the steel sheet-like member obtained in the punching process can be annealed at the same time, making it possible to manufacture the structure efficiently. [Brief explanation of the drawing]

[0007] [Figure 1] Perspective view of the stator according to this embodiment [Figure 2] Cross-section of the stator [Figure 3] Plan view of a steel sheet-like member [Figure 4] Diagram showing the manufacturing method of a stator [Figure 5]Diagram illustrating the coating process [Figure 6] Cross-sectional view of a stator according to another embodiment [Modes for carrying out the invention]

[0008] The illustrated embodiments will be described below. Figure 1 shows a perspective view of the stator 1 as a structure according to the present invention, and Figure 2 shows a partial cross-sectional view thereof. The stator 1 described above is used as a motor component and has a structure in which a steel sheet-like member 2, which is made by punching a steel plate into a predetermined shape, and an amorphous sheet-like member 3, which is made by punching an amorphous thin plate into a predetermined shape, are laminated together and bonded by an adhesive layer 4 made of fluororubber. Stator 1, which is constructed by laminating a steel sheet-like member 2 and an amorphous sheet-like member 3 in this manner, is known to have low iron loss, meaning it has high electrical efficiency when used as a motor, which, for example, makes it possible to miniaturize the motor.

[0009] Figure 3 shows a plan view of the steel sheet-like member 2, where the outer edge is formed in a circular shape, while the inner edge has an evenly spaced uneven shape. The amorphous sheet-like member 3 is also formed in the same shape as the steel sheet-like member 2. The steel sheet-like member 2 is made by punching out a non-oriented electrical steel strip with a thickness of 0.25 to 0.35 mm using a press machine, while the amorphous sheet-like member 3 is made by punching out an amorphous thin sheet with a thickness of 0.015 to 0.030 mm using a press machine. In this embodiment, one amorphous sheet-like member 3 is sandwiched between two steel sheet-like members 2. However, as shown in Figures 6(a) and 6(b), the order and ratio of the layering can be arbitrarily changed.

[0010] The adhesive layer 4 described above is made of vulcanized fluororubber (FKM). Depending on the usage environment, fluororubber has good heat resistance, oil resistance, weather resistance, and chemical resistance, and it is desirable to use fluororubber with an elastic modulus (Young's modulus) in the range of 5 to 10 MPa. Furthermore, compared to thermosetting resins such as those described in Patent Document 1, the above-mentioned fluororubber is superior not only in heat resistance but also in low-temperature environments [resin: -40 to 200°C, fluororubber (FKM): -50 to 300°C]. In addition, because it possesses rubber elasticity, it has excellent resistance to cracking and fatigue failure due to vibration, and can also provide vibration suppression effects. The thickness of the adhesive layer 4 can be reduced to 10 μm or less by using screen printing, as described later, and can be freely adjusted to a thickness of, for example, 1 to 30 μm. To enhance adhesion, a thermosetting resin (e.g., epoxy resin) may be applied to the surface of the steel sheet-like member 2 (or amorphous sheet-like member 3) to a thickness of 0.2 to 1 μm, and then fluororubber may be applied to form the adhesive layer 4. Alternatively, the adhesive layer 4 may be formed by mixing a thermosetting resin with fluororubber.

[0011] According to the stator 1 having the above configuration, high efficiency and high durability can be obtained when the stator 1 is used in a motor. First, in this embodiment, since a steel sheet-like member 2 and an amorphous sheet-like member 3 are laminated together, it is possible to provide a highly efficient stator 1 with low iron loss. Furthermore, in this embodiment, the stator 1 is constructed by bonding a steel sheet-like member 2 and an amorphous sheet-like member 3 with an adhesive layer 4 made of fluororubber, thus achieving high durability. In other words, the elasticity of the fluororubber prevents damage to the adhesive layer 4 due to vibrations acting on the motor, and prevents electrical loss between the steel sheet-like member 2 and the amorphous sheet-like member 3 due to cracks caused by the damage. Furthermore, by setting the thickness of the adhesive layer 4 to 10 μm or less and making the thickness as uniform as possible by the manufacturing method described below, the stator 1 can be made more efficient. That is, by making the thickness of the adhesive layer 4 uniform, homogeneous insulation can be achieved between the adjacent steel sheet-like member 2 and the amorphous sheet-like member 3, and it becomes possible to create a highly efficient motor even with a shorter overall length.

[0012] Hereinafter, a method for manufacturing the stator 1 having the above-described configuration will be described using FIG. 4. First, a punching step A1 is performed in which a steel plate and an amorphous thin plate are punched to obtain a steel sheet-like member 2 and an amorphous sheet-like member 3 having a predetermined shape. Prepare a steel plate and an amorphous thin plate having the above thickness, and put them into a conventionally known press device to punch them into the shapes of the steel sheet-like member 2 and the amorphous sheet-like member 3 as shown in FIG. 3. Here, the remaining materials of the steel sheet-like member and the amorphous sheet-like member after punching can be recycled. On the other hand, in the case of Patent Document 1, since the steel plate and the amorphous thin plate are punched in a state of being adhered by an adhesive, the remaining material has the amorphous thin plate and the adhesive adhered thereto, making recycling difficult.

[0013] Next, a coating step B2 is performed in which fluororubber is applied to the steel sheet-like member 2 and the amorphous sheet-like member 3. In the present embodiment, unvulcanized fluororubber is applied to the steel sheet-like member 2 or the amorphous sheet-like member 3, and here, the application is performed using conventionally known screen printing. In screen printing, first, the steel sheet-like member 2 (the same applies to the amorphous sheet-like member 3, hereinafter abbreviated) is positioned, and a screen having a predetermined thickness with a pattern substantially the same shape as the steel sheet-like member 2 is placed on its upper surface. In that state, liquid fluororubber is placed on top of the screen and spread with a squeegee, causing the fluororubber to penetrate the pattern and adhere to the upper surface of the steel sheet-like member 2. After removing the screen, fluororubber can be applied to the upper surface of the steel sheet-like member 2 with a coating thickness equal to the thickness of the screen, making it possible to apply it uniformly even when the coating thickness is thin.

[0014] In this embodiment, as shown by the dashed line in Figure 3, the fluororubber G is applied to an area offset approximately 0.5 mm inward from the outer and inner edges of the steel sheet-like member 2. This offset amount is set according to the thickness of the fluororubber coating to be applied and the thickness of the adhesive layer 4 upon completion. In the lamination process A3 and heating process A4 described later, the steel sheet-like member 2 and amorphous sheet-like member 3 are pressurized, and when the fluororubber expands, the end face of the adhesive layer 4 coincides with the end faces of the steel sheet-like member 2 and amorphous sheet-like member 3. This method makes it possible to use fluororubber without waste. In addition, in the coating step A2 described above, it is also possible to apply fluororubber to both sides of the steel sheet-like member 2 and omit the application of fluororubber to the amorphous sheet-like member 3. Alternatively, in addition to the above-mentioned screen printing, methods such as spraying fluororubber from a nozzle as described in Patent Document 1, transferring the image by rotating a sponge roll impregnated with fluororubber, or electrodeposition coating can be employed. However, achieving uniformity in coating thickness is more difficult with these methods compared to screen printing.

[0015] Next, lamination step A3 is performed to create a pre-heating structure by laminating the steel sheet-like member 2 coated with fluororubber and the amorphous sheet-like member 3. In lamination process A3, the steel sheet-like member 2 and the amorphous sheet-like member 3 are positioned using the required jigs, and the steel sheet-like member 2 and the amorphous sheet-like member 3 are laminated in the required order as shown in Figure 2. As a result, the steel sheet-like member 2 and the amorphous sheet-like member 3 are temporarily bonded together by the fluororubber to which they are coated before vulcanization, and a pre-heated structure is obtained in which the steel sheet-like member 2 and the amorphous sheet-like member 3 are laminated.

[0016] Finally, heating step A4 is performed in which the pre-heated structure obtained in lamination step A3 is heated and pressurized to vulcanize the fluororubber and form an adhesive layer 4, and the steel sheet-like member 2 is annealed. The above pre-heating structure is placed in the required furnace and heated at approximately 300°C for about 30 minutes while being pressurized at a predetermined pressure. As a result, the unvulcanized fluororubber interposed between the steel sheet-like member 2 and the amorphous sheet-like member 3 is vulcanized to form the adhesive layer 4, and although the coating film becomes slightly thinner due to the pressure, the edge of the adhesive layer 4 extends to the position of the edge of the steel sheet-like member 2 and the amorphous sheet-like member 3. Furthermore, by heating to approximately 300°C, the residual stress generated when the steel sheet-like member 2 is punched out from the steel plate in the punching process A1 is released through annealing. After cooling for a predetermined time and performing post-processing such as deburring as necessary, a stator 1 is obtained by laminating the steel sheet-like member 2 and the amorphous sheet-like member 3.

[0017] According to the above manufacturing method, it is possible to efficiently manufacture the stator 1. Specifically, the process involves first performing a punching step A1 to obtain a steel sheet-like member 2 and an amorphous sheet-like member 3, then applying fluororubber before vulcanization in a coating step A2, and finally laminating the steel sheet-like member 2 and amorphous sheet-like member 3 in a lamination step A3 to create a pre-vulcanization structure. This makes it possible to simultaneously heat and vulcanize the fluororubber before vulcanization and heat and anneal the steel sheet-like member 2 in heating step A4. In contrast, Patent Document 1 describes a method in which a steel plate and an amorphous thin sheet are bonded together with an adhesive, and the adhesive is heat-cured by a heat treatment to create a laminated material. After that, heating had to be performed again to release the residual stress in the steel sheet-like member 2 when the laminated material was punched out.

[0018] In this embodiment, a punching process A1 is performed first to obtain a steel sheet-like member 2 and an amorphous sheet-like member 3, and then the steel sheet-like member 2 and the amorphous sheet-like member 3 are laminated together. In other words, the leftover material generated when punching out the steel sheet-like member 2 from the steel plate can be easily recycled. In contrast, Patent Document 1 involves bonding a steel plate and an amorphous sheet with an adhesive, then heat-curing the adhesive before the punching process. As a result, the remaining material consists of the steel plate and amorphous sheet bonded together with the heat-cured adhesive, making recycling extremely difficult.

[0019] In this embodiment, the structure according to the present invention was described using a motor stator 1, but it can also be used as a structure that constitutes other electrical components such as a motor rotor or a transformer core, and can be manufactured using the same manufacturing method. [Explanation of Symbols]

[0020] 1. Stator (structure) 2. Steel sheet-like member 3. Amorphous sheet-like material 4. Adhesive layer

Claims

1. In a structure in which a steel sheet-like member obtained by punching a steel plate into a predetermined shape and an amorphous sheet-like member obtained by punching an amorphous thin plate into a predetermined shape are laminated together, A structure characterized by having an adhesive layer made of fluororubber formed between the above-mentioned steel sheet-like member and amorphous sheet-like member.

2. A method for manufacturing a structure, characterized by comprising: a punching step of punching out steel plates and amorphous sheets to obtain steel sheet-like members and amorphous sheet-like members having predetermined shapes; a coating step of applying fluororubber to the steel sheet-like members and / or amorphous sheet-like members; a lamination step of laminating the fluororubber-coated steel sheet-like members and amorphous sheet-like members to create a pre-heated structure; and a heating step of heating and pressurizing the pre-heated structure to vulcanize the fluororubber to form an adhesive layer and anneal the steel sheet-like members, thereby creating a structure in which steel plates and amorphous sheets are laminated.

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