JP6954195B2 - Motor core - Google Patents

Description

The present invention relates to a motor core in which electromagnetic steel sheets are laminated and fixed with an adhesive.

In recent years, due to the growing efforts to address global environmental issues, for example, in the fields of automobiles (hybrid vehicles, electric vehicles, fuel cell vehicles, etc.) and home appliances (air conditioners, refrigerators, etc.), products with low energy consumption have become widespread. There is. High-efficiency motors that rotate at high speed are used in these products, and non-oriented electrical steel sheets are used as the core material of the high-efficiency motors.

The motor core includes a stator core and a rotor core arranged inside the stator core. Each is configured by cutting out a non-oriented electrical steel sheet (hereinafter, abbreviated as an electromagnetic steel sheet) in an annular shape, and laminating and fixing two or more pieces of the cut-out sheet. Generally, caulking, welding, or bolting is widely adopted as a method for fixing laminated electromagnetic steel sheets.

After cutting out the electrical steel sheet, strain is introduced into the electrical steel sheet when the laminated electromagnetic steel sheet is fixed by caulking, bolting, or welding in the process of laminating and fixing two or more pieces of the sheet. Therefore, the iron loss of the laminated steel core to which the electromagnetic steel sheet is fixed by a conventionally known method increases. Therefore, various techniques for reducing the strain introduced into the laminated iron core at the time of manufacturing the motor and improving the magnetic characteristics are being studied.

As a solution to this problem, for example, there is a method of punching an electromagnetic steel sheet and then adhering it to form an iron core. Patent Document 1 describes a motor core in which an adhesive is applied to the side surface (back yoke side surface) of the laminated motor core, and Patent Documents 2 to 5 describe a motor core in which an adhesive is applied to the plate surface of a punched electromagnetic steel plate. .. Further, Patent Documents 6 and 7 describe a technique for preventing the adhesive applied to the motor core from squeezing out.

Japanese Unexamined Patent Publication No. 2003-282330 JP-A-2010-136467 JP-A-2017-169249 Japanese Unexamined Patent Publication No. 2012-120299 Japanese Unexamined Patent Publication No. 2015-142453 Japanese Unexamined Patent Publication No. 2014-096429 WO2017-199527

In the conventional technique, since the amount of adhesive squeezed out after drying increases and the adhesive strength decreases, it is necessary to remove the adhesive squeezed out from the punched end face, which causes a problem of increasing the manufacturing cost.

Therefore, the present inventors have studied a technique for inexpensively manufacturing a motor core having high adhesive strength. As a result, by setting the ratio of the sagging height to the sagging width from the punched end face of the electrical steel sheet within a predetermined range, the adhesive strength is high even if the adhesive after drying squeezes out, and the step of removing the spilled adhesive is omitted. It was possible to obtain the knowledge that the manufacturing cost can be reduced.

The present invention has been made based on the above findings, and an object of the present invention is to provide a motor core having high adhesive strength of laminated electromagnetic steel sheets.

In order to achieve the above object, the motor core of the present invention is a motor core formed by laminating a plurality of punched electromagnetic steel sheets and adhering the plate surfaces.
The sagging height L (mm) and the sagging width W (mm) generated on the punched end face of the electromagnetic steel sheet, and the punched end face of the electromagnetic steel sheet of the adhesive layer provided on the plate surface of the electromagnetic steel sheet. The amount of protrusion F (μm) from the surface satisfies the following equations (1) and (2).
0.01 ≤ L / W ≤ 0.04 (1)
1 μm ≤ F ≤ 1 μm + 250 μm × (L / W) (2)

Here, the sagging generated on the punched end face means an inclined surface formed between the plate surface and the punched end face of the electromagnetic steel sheet when the electromagnetic steel sheet is formed by punching. The sagging height is the dimension in the plate thickness direction between the upper end and the lower end of the sagging (tilted surface), and the sagging width is the dimension in the width direction between the upper end and the lower end of the sagging (tilted surface). Say that.

According to the motor core of the present invention, regardless of the size of the motor core, the thickness of the electromagnetic steel plate, the amount of the adhesive applied, and the composition of the adhesive, the sagging height and sagging width ratio L / By controlling the amount of W and the adhesive squeezing out within a predetermined range, it is possible to obtain a motor core having a high adhesive strength of the electromagnetic steel plate.

Further, the method for manufacturing the motor core of the present invention is a method for manufacturing the motor core, in which the adhesive application position from the punched end face is X (mm) and the pressurizing pressure at the time of bonding is P (MPa) in a plan view. Then, depending on the sagging ratio L / W and the pressurizing pressure P at the time of bonding, the adhesive is placed on the inner plate surface of the electromagnetic steel plate at the position X satisfying any of the following formulas (3) to (7). It is characterized by applying.
(A1) When the sagging ratio is 0.01 ≦ L / W ≦ 0.024 and when 0 ≦ P ≦ 125 MPa × (L / W) + 0.5 MPa
0.02 mm ≤ X ≤ 0.1 mm x P + 0.15 mm (3)
(A2) When the sagging ratio is 0.01 ≦ L / W ≦ 0.024 and when 125 MPa × (L / W) + 0.5 MPa ≦ P ≦ 3.5 MPa
0.1 mm x P-12.5 mm x (L / W) -0.03 mm ≤ X ≤ 0.1 mm x P + 0.15 mm (4)
(A3) When the sagging ratio is 0.01 ≦ L / W ≦ 0.024 and when 3.5 MPa ≦ P ≦ 125 MPa × (L / W) + 5.3 MPa
0.1 mm x P-12.5 mm x (L / W) -0.03 mm ≤ X ≤ 0.5 mm (5)
(B1) When the sagging ratio is 0.024 <L / W ≦ 0.04 and 0 ≦ P ≦ 125 MPa × (L / W) + 0.5 MPa
0.02 mm ≤ X ≤ 0.1 mm x P + 0.15 mm (3)
(B2) When the sagging ratio is 0.024 <L / W ≦ 0.04 and 3.5 MPa ≦ P ≦ 125 MPa × (L / W) + 0.5 MPa
0.02 mm ≤ X ≤ 0.5 mm (6)
(B3) When the sagging ratio is 0.024 <L / W ≦ 0.04 and 125 MPa × (L / W) + 0.5 MPa ≦ P ≦ 125 MPa × (L / W) + 5.3 MPa 0.1 mm × P -12.5 mm x (L / W) -0.03 mm ≤ X ≤ 0.5 mm (7)

According to the method for manufacturing a motor core of the present invention, if the adhesive is applied to a position satisfying any one of the formulas (3) to (7) according to the sagging ratio and the pressurizing pressure at the time of bonding, the amount of protrusion Can be controlled within the specified range, so high adhesive strength can be obtained.

According to the present invention, a motor core having high adhesive strength of laminated electromagnetic steel sheets can be obtained at low cost.

A motor core according to an embodiment of the present invention is shown, and is a plan view of an electromagnetic steel sheet constituting the motor core. The same is the front view. In the same, (a) is a cross-sectional view of a main part of a motor core, (b) is a cross-sectional view of a main part of another motor core, and (c) is a cross-sectional view of a main part of an electromagnetic steel sheet. (D) is a cross-sectional view of a waist portion of an electromagnetic steel sheet, and is a view to which an adhesive is applied. In the same, (a) is a plan view of the electromagnetic steel sheet in a state where an adhesive is applied, and (b) is an enlarged view of a main part in (a). It is a figure which shows the tension method at the time of investigating the adhesive strength. It is a figure which shows the relationship between the adhesive strength, the sagging ratio L / W, and the adhesive squeeze amount F. It is a figure which shows the relationship between the adhesive strength, the pressurizing pressure P, and the adhesive application position X at a sagging ratio L / W = 0.013. It is a figure which shows the relationship between the adhesive strength, the pressurizing pressure P, and the adhesive application position X at a sagging ratio L / W = 0.024. It is a figure which shows the relationship between the adhesive strength, the pressurizing pressure P, and the adhesive application position X at a sagging ratio L / W = 0.037.

(Motor core)
Hereinafter, embodiments of the motor core according to the present invention will be described with reference to the drawings. FIG. 1 is a plan view of the electromagnetic steel sheet 10 constituting the motor core according to the embodiment, and FIG. 2 is a front view of the motor core 101. The electromagnetic steel sheet 10 is formed by punching a conventionally known electrical steel sheet such as a non-oriented electrical steel sheet or a grain-oriented electrical steel sheet in an annular shape, and is formed in the axial direction of the motor core 101 (in FIG. 1). The motor core 101 is formed by stacking a plurality of electrical steel sheets 10 and 10 adjacent to each other in the axial direction with an adhesive while being laminated in a plurality of directions perpendicular to the paper surface (vertical direction in FIG. 2).

An insulating film (not shown) is formed on the surface of the electrical steel sheet 10 in order to maintain electrical insulation of each electrical steel sheet 10 in the motor core (laminated steel core) 101. As the insulating film, a conventionally known insulating film such as a film composed of an inorganic substance or an organic substance or a film obtained by mixing an inorganic substance and an organic substance is used.

As shown in FIGS. 3A to 3C, sagging 12 occurs on the punched end surface 11 of the punched electrical steel sheet 10. As shown in FIG. 3C, the sagging 12 of the punched end surface 11 refers to an inclined surface 12 formed between the plate surface 10a of the electrical steel sheet 10 and the punched end surface 11.

Further, as shown in FIG. 3A, the tip of the adhesive after drying is often outside the electrical steel sheet 10 from the punched end surface 11 in a plan view, but as shown in FIG. 3B, In a plan view, it may be inside the electromagnetic steel sheet 10 from the punched end surface 11.
In this case, when the tip of the adhesive after drying is outside the electrical steel sheet 10 from the punched end surface 11, the amount of protrusion F after drying is several μm from the punched end surface 11, and when it is inside the electromagnetic steel sheet 10, after drying. The protrusion amount F is − (minus) several μm from the punched end face 11.
Further, in the present embodiment, the adhesive squeeze amount F (μm) after drying is determined regardless of the motor core size, the thickness of the electromagnetic steel sheet, the amount of the adhesive applied, and the composition of the adhesive, and the electromagnetic steel sheet 10 is viewed in plan view. The ratio L / W of the sagging height L (mm) and the sagging width W (mm) inside the electromagnetic steel sheet 10 from the punched end face 11 satisfies the following formulas (1) and (2).
0.01 ≤ L / W ≤ 0.04 (1)
1 μm ≤ F ≤ 1 μm + 250 μm × (L / W) (2)

The reason for the limitation of the formula (1) will be described based on the experimental results.
(A) Effect of motor core size on adhesive squeeze amount and adhesive strength As shown in A-1 to 15 of Table 1, an electromagnetic steel sheet with a plate thickness of 0.25 mm is punched with different clearances, and the outer diameter, inner diameter, and punching of the motor core. The sagging ratio L / W of the end face was changed. After that, an adhesive was applied to the outer peripheral portion and the inner peripheral portion of the motor core at a position 0.3 mm from the punched end face with a height of 0.1 mm and a width of 0.03 mm, and 12 sheets were laminated and then pressurized at 3 MPa. Glued. After the adhesive was dried, the adhesive strength, sagging height, sagging width, and adhesive squeeze amount were evaluated by the following methods.
The clearance refers to a gap between a punch and a die used when punching an electromagnetic steel sheet from a material.
(1) Adhesive strength As the adhesive strength, as shown by an arrow in FIG. 5, following the method of Patent Document 5, the motor core 101 is pulled in parallel in the axial direction and peeled off to the electromagnetic steel plates 10 and 10 in which the plate surfaces are adhered to each other. The load at the time of occurrence was measured, and 80 N or more was regarded as acceptable.
(2) Evaluation of sagging height L, sagging width W, and adhesive squeeze amount F A cross section of the motor core was cut out so that the peeled portion had an observation surface as shown in FIG. 3 (a). After that, the height of the sagging and the sagging width were measured as shown in FIG. 3 (c). On the other hand, as shown in FIG. 3A, the amount of adhesive squeezed out was measured at the most protruding portion from the punched end face.

(B) Effect of plate thickness on adhesive squeeze amount and adhesive strength As shown in Table 1 B-1 to 15, an electromagnetic steel sheet with a plate thickness of 0.15 to 0.30 mm is punched with different clearances, and the punched end face of the motor core. The sagging ratio L / W was changed. After that, an adhesive was applied to the outer peripheral portion and the inner peripheral portion of the motor core at a position 0.3 mm from the punched end face with a height of 0.1 mm and a width of 0.03 mm, and 12 sheets were laminated and then pressurized at 3 MPa. Glued. After the adhesive was dried, the adhesive strength, sagging height, sagging width, and adhesive squeeze amount were evaluated by the same method as in (A).

(C) Effect of adhesive application amount on adhesive squeeze amount and adhesive strength As shown in C-1 to C-1 of Table 1, an electromagnetic steel plate with a plate thickness of 0.25 mm was punched with different clearances, and the sagging ratio of the punched end face was L. / W was changed. After that, the adhesive is punched out from the outer peripheral portion and the inner peripheral portion of the motor core at a position of 0.3 mm from the end face, and the height is 0.1 to 1.0 mm, the width is 0.03 to 0.3 mm, or the entire plate surface of the motor core. After laminating 12 sheets, the mixture was pressurized at 3 MPa and adhered. After the adhesive was dried, the adhesive strength, sagging height, sagging width, and adhesive squeeze amount were evaluated by the same method as in (A).

(D) Effect of adhesive composition on adhesive squeeze amount and adhesive strength As shown in C-1 to C-1 of Table 1, an electromagnetic steel sheet having a thickness of 0.25 mm was punched with different clearances, and the sagging ratio of the punched end face was L. / W was changed. After that, the adhesive composition was changed for each of the outer peripheral portion and the inner peripheral portion of the motor core, and the adhesive was applied at a position 0.3 mm from the punched end face at a height of 0.1 mm and a width of 0.03 mm, and 12 sheets were laminated. The mixture was pressurized at 3 MPa and adhered. After the adhesive was dried, the adhesive strength, sagging height, sagging width, and adhesive squeeze amount were evaluated by the same method as in (A).

If the sagging ratio is the same from the experimental results of (A) to (D), the amount of protrusion and the amount of protrusion even if the size of the motor core, the thickness of the electromagnetic steel plate, the amount of adhesive applied per motor core, and the composition of the adhesive are different. It can be seen that it does not affect the adhesive strength. On the other hand, it can be seen that if the sagging ratio is different, the amount of protrusion and the adhesive strength will change.

The reason for limiting the formula (2) will be described based on the experimental results.
A non-oriented electrical steel sheet having a plate thickness of 0.25 mm was punched into a hollow circular shape having an outer diameter of 180 mm and an inner diameter of 120 mm by changing the clearance, and the sagging ratio L / W of the punched end face was changed. After that, an adhesive was applied to the outer peripheral portion and the inner peripheral portion of the motor core at a position of 0.3 mm from the punched end face with a height of 0.1 mm and a width of 0.03 mm, and 12 sheets were laminated and then added at 1 to 10 MPa. Pressure treatment was performed to change the amount of protrusion F. After the adhesive was cured and dried, the amount of protrusion from the punched end face was measured by the same method as in Table 1, and the adhesive strength of this motor core was investigated.

In FIG. 6, the results of Table 2 are plotted with the horizontal axis representing the amount of adhesive squeeze out F (μm) and the vertical axis representing the sagging ratio (L / W). In FIG. 6, “◯” indicates a case where the adhesive strength is high at 80 N or more, and “x” indicates a case where the adhesive strength is low at less than 80 N.
As shown in Table 2 and FIG. 6, when the sagging ratio L / W is less than 0.01 or more than 0.04, the adhesive strength is relatively low, less than 80 N, even if the amount of adhesive squeeze out changes. On the other hand, when the sagging ratio is 0.01 to 0.04, the upper limit of the amount of adhesive squeeze out to obtain the adhesive strength of 80 N or more becomes wider as the sagging ratio is larger. That is, it can be seen that the upper limit of the amount of adhesive squeeze out depends on the sagging ratio L / W and becomes 80 N or more when F ≦ 1 μm + 250 μm × (L / W).

(1) Sagging ratio: L / W (-)
0.01 ≤ L / W ≤ 0.04
From the results in Table 1, the lower limit of the sagging ratio is 0.01 or more. If the sagging ratio is less than 0.01, the space required for bonding is reduced, so that the bonding strength cannot be expected to be improved.
On the other hand, the upper limit of the sagging ratio is 0.04 or less. If the sagging ratio exceeds 0.04, the adhesive area of the adhesive and the electromagnetic steel sheet laminated on the adhesive is reduced, so that the adhesive strength cannot be expected to be improved.

(2) Amount of adhesive squeezed out from the punched end face after drying: F (μm)
1 μm ≤ F ≤ 1 μm + 250 μm × (L / W)
The amount of adhesive squeeze out F (μm) after drying from the punched end surface reduces the adhesive strength in plate surface adhesion. When F is less than 1 μm (including a negative value in the amount of protrusion), the adhesive area is reduced, so that the adhesive strength is less than 80 N. Therefore, the lower limit of F is set to 1 μm or more.
On the other hand, from the results in Table 2, the adhesive strength decreases as F increases. Further, since the adhesive strength changes depending on the sagging ratio, the upper limit of F changes. Therefore, from the viewpoint of ensuring the adhesive strength, the upper limit of F is set to 1 μm + 250 μm × (L / W) or less. Therefore, the amount of adhesive squeezed out from the punched end face is 1 μm ≦ F ≦ 1 μm + 250 μm × (L / W).

(Manufacturing method of motor core)
Hereinafter, embodiments of the method for manufacturing a motor core according to the present invention will be described with reference to the drawings.

As shown in FIG. 4, the adhesive coating position 13 is provided on the plate surface 10a of the electromagnetic steel plate 10 at the adhesive coating position 13a provided on the outer peripheral side of the electromagnetic steel plate 10 and on the inner peripheral side of the electromagnetic steel plate 10. It is composed of an adhesive application position 13b, an adhesive application position 13c provided on the side surface side of the tooth 15, and an adhesive application position 13d provided on the tip side of the tooth 15.
The adhesive application position 13a is arranged in a circular shape in a plan view along the outer circumference of the electromagnetic steel plate 10, and the adhesive is formed so as to be X (mm) from the punched end face (back yoke end face) 11a in the plan view and inside the electromagnetic steel plate 10. Is applied.
The adhesive application position 13b is arranged in an intermittent circular shape in a plan view along the inner circumference of the electromagnetic steel plate 10, and is located inside the electromagnetic steel plate 10 from the punched end surface (yoke inner peripheral end surface) 11b to X (mm) in the plan view. Apply adhesive to.
The adhesive application position 13c is arranged linearly along the side surfaces parallel to each other of each tooth 15, and the adhesive is arranged so as to be inside the electromagnetic steel plate 10 from the punched end surface (teeth side surface) 11c to X (mm) in a plan view. Is applied.
The adhesive application position 13d is arranged linearly along the tip of each tooth 15, and the adhesive is applied so as to be inside the electromagnetic steel plate 10 from the punched end face (teeth end face) 11d to X (mm) in a plan view. ..

The adhesive application position X is determined by the values of the sagging ratio L / W and the pressurizing pressure P so that the amount of adhesive squeeze out falls within the range of the equation (2). From the punched end face 11, the coating is applied to the inside of the electrical steel sheet 10 in the range of X (mm) within the range satisfying any one of the following formulas (3) to (7).
(A1) When the sagging ratio is 0.01 ≦ L / W ≦ 0.024 and when 0 ≦ P ≦ 125 MPa × (L / W) + 0.5 MPa
0.02 mm ≤ X ≤ 0.1 mm x P + 0.15 mm (3)
(A2) When the sagging ratio is 0.01 ≦ L / W ≦ 0.024 and when 125 MPa × (L / W) + 0.5 MPa ≦ P ≦ 3.5 MPa
0.1 mm x P-12.5 mm x (L / W) -0.03 mm ≤ X ≤ 0.1 mm x P + 0.15 mm (4)
(A3) When the sagging ratio is 0.01 ≦ L / W ≦ 0.024 and when 3.5 MPa ≦ P ≦ 125 MPa × (L / W) + 5.3 MPa
0.1 mm x P-12.5 mm x (L / W) -0.03 mm ≤ X ≤ 0.5 mm (5)
(B1) When the sagging ratio is 0.024 <L / W ≦ 0.04 and 0 ≦ P ≦ 125 MPa × (L / W) + 0.5 MPa
0.02 mm ≤ X ≤ 0.1 mm x P + 0.15 mm (3)
(B2) When the sagging ratio is 0.024 <L / W ≦ 0.04 and 3.5 MPa ≦ P ≦ 125 MPa × (L / W) + 0.5 MPa
0.02 mm ≤ X ≤ 0.5 mm (6)
(B3) When the sagging ratio is 0.024 <L / W ≦ 0.04 and 125 MPa × (L / W) + 0.5 MPa ≦ P ≦ 125 MPa × (L / W) + 5.3 MPa 0.1 mm × P -12.5 mm x (L / W) -0.03 mm ≤ X ≤ 0.5 mm (7)

The lower limit of the adhesive application position X will be described. When X <0.02 mm or X <0.1 mm × P-12.5 mm × (L / W) −0.03 mm, the amount of adhesive squeeze out is too large to obtain an adhesive strength of 80 N or more. Therefore, the lower limit of the adhesive application position is X ≧ 0.02 mm or X ≧ 0.1 mm × P-12.5 mm × (L / W) −0.03 mm.
The upper limit of the adhesive application position X will be described. When X> 0.5 mm or X> 0.1 mm × P + 0.15 mm, the amount of adhesive squeeze out is less than 1 μm, and the amount of squeeze out is the same as before, but the adhesive does not sufficiently reach the sagging part. Therefore, the adhesive area of the electromagnetic steel plate laminated on it is reduced. As a result, an adhesive strength of 80 N or more cannot be obtained. Therefore, the upper limit of the adhesive application position is X ≦ 0.5 mm or X ≦ 0.1 mm × P + 0.15 mm.

The pressurizing pressure P at the time of bonding can be changed according to the sagging ratio L / W within a range in which the adhesive does not squeeze out. It is preferably 0 to 10 MPa.

In the present embodiment, an example in which a two-component mixed type epoxy adhesive is used as the adhesive has been described, but in addition, a one-component thermosetting epoxy adhesive that cures by heating can be used. ..
Examples of the epoxy resin include epoxy resins selected from glycidyl ether type, glycidyl ester type, glycidyl amine type, linear aliphatic epoxiside type, alicyclic epoxiside type and the like. In particular, glycidyl ether type epoxy equivalents in the range of 150 to 300 are preferable. These epoxy resins may be used alone or in combination of two or more, depending on desired properties such as strength, toughness, dielectric property, permeability, strain suppression property, and quick curing property. .. As a combination, it is preferable to use it in combination with a urethane-modified epoxy resin. The ratio of the normal epoxy resin to the urethane-modified epoxy resin is preferably in the range of 0.2: 0.8 to 0.7: 0.3 in order to impart the desired toughness.

In addition, if necessary, rust preventives (for example, aluminum dihydrogen tripolyphosphate, zinc phosphate, aluminum phosphate, etc.), fillers (for example, calcium carbonate, clay, talc, silica, carbon, iron oxide, mica, etc.), reaction A sex diluent (for example, allyl glycidyl ether, phenyl glycidyl ether, etc.), a plasticizer (for example, phthalate ester, furfuryl alcohol, etc.), and a synthetic rubber (for example, NBR, SBR, etc.) can be appropriately blended.

When the adhesive is cured, it may be cured at room temperature, but it can also be cured by heating. Heat curing can improve the productivity of the adhesive-fixed laminated iron core.

As the rubber component of the component, synthetic rubber is preferable, and one having rubber-like elasticity at room temperature is particularly preferable. Rubber components include acrylic rubber, nitrile rubber, styrene butadiene rubber, butadiene methyl acrylate acrylonitrile rubber, butadiene rubber, carboxy-containing acrylonitrile butadiene rubber, vinyl-containing acrylonitrile butadiene rubber, silicone rubber, urethane rubber, synthetic rubber such as polyvinyl butyral, and rubber. Examples thereof include rubber-modified polymer compounds such as modified epoxy resins, and polymer epoxy resins having a mass average molecular weight of 10,000 or more.

As the content of the rubber component, 40% by mass or more is used in the solid content of the thermosetting resin composition. When the content of the rubber component is less than 40% by mass, the fluidity of the thermosetting resin composition at the time of heating and pressurizing becomes large, and when the laminated core is formed, the thermosetting resin composition from the inner and outer peripheral portions of the electromagnetic steel plate is used. The amount of protrusion of the object (adhesive layer) increases. The content of the rubber component is preferably 80% by mass or less in the solid content of the thermosetting resin composition.

The thickness of the adhesive to be applied is preferably 0.2 mm or less. If it exceeds 0.2 mm, the bonding cost increases, so 0.2 mm or less is preferable.

If the width of the adhesive to be applied exceeds 0.1 mm, the bonding cost increases, so that the width is preferably 0.1 mm or less.

If the weight of the adhesive material applied to each punched electrical steel sheet exceeds 2.0 mg / sheet, the adhesive cost increases, so the weight is preferably 2.0 mg / sheet or less.

The thickness of the electromagnetic steel sheet used for the motor core is not limited. However, the thinner the plate, the more difficult it is to crimp the motor core. Therefore, it is preferable to use an electromagnetic steel sheet having a thickness of 0.25 mm or less, which makes it difficult to crimp.

The dimensions of the motor core when punched from the electrical steel sheet are not particularly limited. The punching dimensions can be changed according to the required application.

Next, an embodiment will be described.

A non-oriented electrical steel sheet having a plate thickness of 0.20 mm was punched into a hollow circular shape having an outer diameter of 180 mm and an inner diameter of 120 mm by changing the clearance, and the sagging ratio L / W of the punched end face was changed. After that, an adhesive was applied to the outer peripheral portion and the inner peripheral portion of the motor core at a position 0.3 mm from the punched end face with a height of 0.1 mm and a width of 0.03 mm, respectively, and 12 sheets were laminated and bonded, and then at 1 to 10 MPa. The pressure treatment was performed to change the amount of protrusion F. After the adhesive was cured and dried, the amount of protrusion from the punched end face was measured by the same method as in Table 1, and the adhesive strength of this motor core was investigated. Adhesive strength of 80 N or more was accepted. The results are shown in Table 3 and FIG.

No. with a sagging ratio L / W = 0.004. In each of 1 to 7, the adhesive strength was less than 80 N.
No. with a sagging ratio L / W = 0.013, 0.024, 0.037. In each of 8, 15 and 22, the amount of protrusion was less than 1 μm, which is a conventional example, and the adhesive strength was less than 80 N. No. In 11 to 14, 20 to 21, 28, the adhesive strength decreased as the amount of adhesive squeeze out increased, and the adhesive strength was less than 80 N.
No. with a sagging ratio L / W = 0.045. In each of 29 to 35, the adhesive strength was less than 80 N.
In contrast to these, No. In 9 to 10, 16 to 19, 23 to 27, the adhesive strength was 80 N or more because the sagging ratio L / W and the adhesive squeeze amount F were in an appropriate range.

From FIG. 6, when the sagging ratio L / W is less than 0.01, the space required for bonding is reduced, so that the bonding strength cannot be expected to be improved. If the sagging ratio exceeds 0.04, the adhesive area is reduced and the adhesive strength cannot be expected to improve. When the sagging ratio is 0.01 to 0.04, improvement in adhesive strength cannot be expected even if the protrusion amount F is less than 1 μm. When the protrusion amount F (μm) exceeds 1 μm + 250 μm × (L / W), the adhesive strength becomes less than 80 N. On the other hand, it can be seen that when the sagging ratio is 0.01 to 0.04 and the amount of protrusion satisfies the following formulas (1) and (2), sufficient adhesive strength can be obtained.
0.01 ≤ L / W ≤ 0.04 (1)
1 μm ≤ F ≤ 1 μm + 250 μm × (L / W) (2)

A non-oriented electrical steel sheet with a plate thickness of 0.20 mm is punched into a hollow circular shape with an outer diameter of 180 mm and an inner diameter of 120 mm by changing the clearance, and the sagging ratio L / W of the punched end face is 0.013, 0.024, 0. It was changed to .037 respectively. After that, 12 sheets were laminated on the outer peripheral portion and the inner peripheral portion of the motor core to make the thickness of the adhesive 0.1 mm and the width 0.03 mm, and 0.01 mm, 0.03 mm, and 0 from the punched end faces of the inner and outer circumferences, respectively. It was applied at the positions of .15 mm, 0.30 mm, 0.45 mm and 0.60 mm. After bonding, pressure treatment was performed at a pressure of 1 to 10 MPa to change the amount of protrusion F. After the adhesive was cured and dried, the amount of protrusion from the punched end face was measured, and the adhesive strength of this motor core was investigated. The results are shown in Tables 4-6. Further, FIGS. 7 to 9 show the adhesive application position and the range of the pressurizing pressure at which the adhesive strength becomes 80 N or more when the sagging ratios L / W are 0.013, 0.024, and 0.037, respectively.
In FIGS. 7 to 9, the results of Tables 4 to 6 are plotted with the horizontal axis representing the adhesive application position X (mm) and the vertical axis representing the pressurizing pressure P (MPa). In FIGS. 7 to 9, "◯" indicates a case where the adhesive strength is 80 N or more and high, and "x" indicates a case where the adhesive strength is less than 80 N and low.

As shown in Table 4 and FIG. 7, when the sagging ratio L / W = 0.013, a-1, a-4 to 7, a-11 to 14, a-18 to 21, a-24 to 28, In the combination of the adhesive application position and the pressurizing pressure in a-30 to 42, the amount of adhesive squeeze out was less than 1 μm or more than 4 μm, and the adhesive strength was less than 80 N, which was unacceptable. On the other hand, in the combination of the adhesive application position and the pressurizing pressure at a-2 to 3, a-8 to 10, a-15 to 17, a-22 to 23, and a-29, (3) to (3) to ( The equation 5) was satisfied, the amount of adhesive squeezing out was 1 to 4 μm, and the adhesive strength was 80 N or more, which was acceptable.

As shown in Table 5 and FIG. 8, when the sagging ratio L / W = 0.024, b-1, b-4 to 7, b-11 to 13, b-18 to 20, b-24 to 27, In the combination of the adhesive application position and the pressure pressure at b-30 to 34 and b-36 to 42, the amount of adhesive squeeze out was less than 1 μm or more than 7 μm, and the adhesive strength was less than 80 N, which was unacceptable. On the other hand, in the combination of the adhesive application position and the pressurizing pressure at b-2 to 3, b-8 to 10, b-14 to 17, b-21 to 23, b-28 to 29, and b-35, , (3) to (5) were satisfied, the amount of adhesive squeezed out was 1 to 7 μm, and the adhesive strength was 80 N or more, which was acceptable.

As shown in Table 6 and FIG. 9, when the sagging ratio L / W = 0.037, c-1, c-4 to 7, c-11 to 13, c-18 to 19, c-24 to 26, In the combination of the adhesive application position and the pressurizing pressure at c-30 to 33, c-36 to 40, and c-42, the amount of adhesive squeeze out is less than 1 μm or more than 10 μm, and the adhesive strength is less than 80 N, which is a failure. Met. On the other hand, the adhesive application positions at c-2 to 3, c-8 to 10, c-14 to 17, c-20 to 23, c-28 to 29, c-34 to 35, and c-41. The combination of pressurizing pressure satisfied the equations (3), (6), and (7), the amount of adhesive squeezing out was 1 to 10 μm, and the adhesive strength was 80 N or more, which was acceptable.

Based on the above, the adhesive application position X is determined by the values of the sagging ratio L / W and the pressurizing pressure P so that the amount of adhesive squeeze out falls within the range of the above equation (2), and the punched end face 11 to the above (3). By coating the inside of the electromagnetic steel plate 10 in the range of X (mm) within the range satisfying any one of the formulas (7), the amount of protrusion can be controlled within the specified range and high adhesive strength can be obtained. I understand.

10 Electrical steel sheet 10a Plate surface 11, 11a to 11d Punched end surface 12 Dripping 13, 13a to 13d Adhesive layer 15 Teeth 101 Motor core

Claims (2)

In a motor core in which a plurality of punched electrical steel sheets are laminated and the plate surfaces of the plurality of electrical steel sheets are bonded to each other.
The sagging height of the punched end face of the electromagnetic steel sheet is L (mm), the sagging width of the punched end face is W (mm), and from the punched end face of the electromagnetic steel sheet of the adhesive layer provided on the plate surface of the electromagnetic steel sheet. A motor core characterized in that the following equations (1) and (2) are satisfied, where the amount of protrusion after drying is F (μm).
0.01 ≤ L / W ≤ 0.04 (1)
1 μm ≤ F ≤ 1 μm + 250 μm × (L / W) (2) A method for manufacturing a motor core according to claim 1, wherein the motor core is manufactured.
When the adhesive application position from the punched end face is X (mm) and the pressurizing pressure at the time of bonding is P (MPa) in a plan view, the sagging ratio L / W and the pressurizing pressure P at the time of bonding are affected. A method for manufacturing a motor core, which comprises applying an adhesive to a plate surface inside the electromagnetic steel plate at a position satisfying any of the following formulas (3) to (7).
(A1) When the sagging ratio is 0.01 ≦ L / W ≦ 0.024 and when 0 ≦ P ≦ 125 MPa × (L / W) + 0.5 MPa
0.02 mm ≤ X ≤ 0.1 mm x P + 0.15 mm (3)
(A2) When the sagging ratio is 0.01 ≦ L / W ≦ 0.024 and when 125 MPa × (L / W) + 0.5 MPa ≦ P ≦ 3.5 MPa
0.1 mm x P-12.5 mm x (L / W) -0.03 mm ≤ X ≤ 0.1 mm x P + 0.15 mm (4)
(A3) When the sagging ratio is 0.01 ≦ L / W ≦ 0.024 and when 3.5 MPa ≦ P ≦ 125 MPa × (L / W) + 5.3 MPa
0.1 mm x P-12.5 mm x (L / W) -0.03 mm ≤ X ≤ 0.5 mm (5)
(B1) When the sagging ratio is 0.024 <L / W ≦ 0.04 and 0 ≦ P ≦ 125 MPa × (L / W) + 0.5 MPa
0.02 mm ≤ X ≤ 0.1 mm x P + 0.15 mm (3)
(B2) When the sagging ratio is 0.024 <L / W ≦ 0.04 and 3.5 MPa ≦ P ≦ 125 MPa × (L / W) + 0.5 MPa
0.02 mm ≤ X ≤ 0.5 mm (6)
(B3) When the sagging ratio is 0.024 <L / W ≦ 0.04 and 125 MPa × (L / W) + 0.5 MPa ≦ P ≦ 125 MPa × (L / W) + 5.3 MPa 0.1 mm × P -12.5 mm x (L / W) -0.03 mm ≤ X ≤ 0.5 mm (7)

Images