JP2021019375A - Laminated core, and manufacturing method thereof, and rotary electric machine - Google Patents

Abstract

To improve the joining strength at the boundary between a set in which electromagnetic steel sheets are joined by caulking and a set in which electromagnetic steel sheets are joined by adhesion.SOLUTION: In a laminated core that includes a plurality of electromagnetic steel sheets 40 laminated to each other, and in which all sets of electromagnetic steel sheets 40 adjacent to each other in the stacking direction are fixed to each other includes a first set in which the electromagnetic steel sheets 40 are crimped and not bonded to each other, and a second set in which the electromagnetic steel sheets 40 are bonded to each other and not crimped, and the electromagnetic steel sheets 40 at the boundary portion M1 between the first set and the second set are bonded to each other by an adhesive having an SP value of 7.8 to 10.7 (cal/cm3)1/2.SELECTED DRAWING: Figure 5

Description

The present invention relates to a laminated core, a method for manufacturing the same, and a rotary electric machine.

Conventionally, a laminated core as described in Patent Document 1 below has been known. In this laminated core, electromagnetic steel sheets adjacent to each other in the laminated direction are joined by both bonding and caulking methods.

JP 2015-142453

Patent Document 1 describes a combination of a set in which electromagnetic steel sheets are joined by caulking and a set in which electromagnetic steel sheets are joined by adhesion to improve dimensional accuracy and mechanical strength without deteriorating magnetic characteristics. Is not mentioned, and of course there is room for improvement in improving the joint strength at the boundaries of these sets.

The present invention has been made in view of the above-mentioned circumstances, and is intended to improve the bonding strength at the boundary between a group in which electromagnetic steel sheets are joined by caulking and a group in which electromagnetic steel sheets are bonded by adhesion. With the goal.

The present invention has the following aspects.
[1] A plurality of electromagnetic steel plates laminated to each other are provided.
It is a laminated core in which all sets of electromagnetic steel sheets adjacent to each other in the laminating direction are fixed to each other.
Includes a first set in which the electrical steel sheets are crimped and not bonded, and a second set in which the electrical steel sheets are bonded and not crimped.
The electrical steel sheets at the boundary between the first set and the second set are bonded to each other with an adhesive having an SP value of 7.8 to 10.7 (cal / cm ³ ) ^1/2 . Laminated core.
[2] The method according to [1], wherein the adhesive portion made of the adhesive that adheres the electromagnetic steel plates to each other at the boundary portion is provided in a dot shape on the same circumference as the caulking of the boundary portion in a plan view. Laminated core.
[3] At the boundary portion, the tip of the crimping convex portion of the first set of electromagnetic steel sheets is adhered to the surface of the second set of electromagnetic steel sheets on the caulking convex portion side with the adhesive. The laminated core according to [1] or [2].
[4] At the boundary portion, at least a part of the portion other than the caulking of the first set of electromagnetic steel sheets is adhered to the surface of the second set of electromagnetic steel sheets on the caulking side with the adhesive. , [1] or [2].
[5] The laminated core according to [4], wherein the thickness of the adhesive portion made of the adhesive at the boundary portion in the laminating direction is the same as the height of the caulking convex portion of the caulking.
[6] The absolute value of the difference between the SP value of the punching oil used for punching of the electromagnetic steel sheet and the SP value of the adhesive is 0.1 to 2.3 (cal / cm ³ ) ^1/2 . , [1] to [5].
[7] The second set of electrical steel sheets are bonded to each other with an adhesive having an SP value of 7.8 to 10.7 (cal / cm ³ ) ^1/2 , [1] to [6]. The laminated core described in any of.
[8] The electrical steel sheet has an annular core back portion and a plurality of pieces that protrude inward in the radial direction of the core back portion from the core back portion and are arranged at intervals in the circumferential direction of the core back portion. The laminated core according to any one of [1] to [7], comprising a teeth portion.
[9] A rotary electric machine including the laminated core according to any one of [1] to [8].
[10] The method for manufacturing a laminated core according to [1].
An adhesive having an SP value of 7.8 to 10.7 (cal / cm ³ ) ^1/2 is applied to either or both of the first set of electrical steel sheets and the second set of electrical steel sheets. A method for manufacturing a laminated core, which is applied, cured, and bonded to each other.
[11] The adhesive is applied to at least a part of the portion other than the caulking of the first set of electrical steel sheets so as to be thicker than the height of the caulking convex portion of the caulking.
The adhesive is cured in a state where the tip of the crimping convex portion is in contact with the second set of electromagnetic steel sheets, and the electromagnetic steel sheets are formed by an adhesive portion having the same thickness as the height of the caulking convex portion. The method for producing a laminated core according to [10], wherein the laminated cores are bonded to each other.
[12] The electromagnetic steel sheet is manufactured by punching using punching oil.
The lamination according to [10] or [11], wherein the absolute value of the difference between the SP value of the punching oil and the SP value of the adhesive is 0.1 to 2.3 (cal / cm ³ ) ^1/2. How to make the core.

According to the present invention, it is possible to improve the joining strength at the boundary portion between the set in which the electromagnetic steel sheets are joined by caulking and the set in which the electromagnetic steel sheets are joined by adhesion.

It is a top view of the rotary electric machine which concerns on one Embodiment of this invention. It is a top view of the stator included in the rotary electric machine shown in FIG. It is a side view of the stator included in the rotary electric machine shown in FIG. It is a top view of the electromagnetic steel plate and the caulking of the stator provided in the rotary electric machine shown in FIG. 4A is a cross-sectional view of the electromagnetic steel plate of FIG. 4, FIG. 5A is a cross-sectional view taken along the line AA, and FIG. 5B is a cross-sectional view taken along the line BB. It is a top view which showed an example of the electromagnetic steel plate, the caulking and the adhesive part in the boundary part M1. 6 is a cross-sectional view of a joint portion between electromagnetic steel sheets at the boundary portion M1 of FIG. 6, FIG. 7A is a cross-sectional view taken along the line CC, and FIG. 7B is a cross-sectional view taken along the line DD. FIG. 8A is a cross-sectional view of the joint portion between the electromagnetic steel sheets at the boundary portion M2, FIG. 8A is a cross-sectional view of the vicinity of the first caulking portion, and FIG. 7B is a cross-sectional view of the vicinity of the second caulking portion. It is a top view of the electromagnetic steel plate and the adhesive part of the stator provided in the rotary electric machine shown in FIG. It is a top view which showed the other example of the electromagnetic steel plate, the caulking and the adhesive part in the boundary part M1.

Hereinafter, the rotary electric machine according to the embodiment of the present invention will be described with reference to the drawings. In the present embodiment, an electric motor, specifically an AC electric motor, more specifically, a synchronous motor, and even more specifically, a permanent magnet field type electric motor will be described as an example of a rotary electric motor. This type of electric motor is suitably adopted for, for example, an electric vehicle.

As shown in FIGS. 1 and 2, the rotary electric machine 10 includes a stator 20, a rotor 30, a case 50, and a rotary shaft 60. The stator 20 and rotor 30 are housed in a case 50. The stator 20 is fixed to the case 50.
In this embodiment, as the rotary electric machine 10, an inner rotor type in which the rotor 30 is located inside the stator 20 is adopted. However, as the rotary electric machine 10, an outer rotor type in which the rotor 30 is located outside the stator 20 may be adopted. Further, in the present embodiment, the rotary electric machine 10 is a 12-pole 18-slot three-phase AC motor. However, for example, the number of poles, the number of slots, the number of phases, and the like can be changed as appropriate. The rotary electric machine 10 can rotate at a rotation speed of 1000 rpm by applying an exciting current having an effective value of 10 A and a frequency of 100 Hz to each phase, for example.

The stator 20 includes a stator core 21 and a winding (not shown).
The stator core 21 includes an annular core back portion 22 and a plurality of teeth portions 23. In the following, the axial direction of the stator core 21 (core back portion 22) (the central axis O direction of the stator core 21) is referred to as the axial direction, and the radial direction of the stator core 21 (core back portion 22) (perpendicular to the central axis O of the stator core 21). The direction) is called the radial direction, and the circumferential direction of the stator core 21 (core back portion 22) (the direction that orbits around the central axis O of the stator core 21) is called the circumferential direction.

The core back portion 22 is formed in an annular shape in a plan view of the stator 20 when viewed from the axial direction.
The plurality of tooth portions 23 project from the core back portion 22 inward in the radial direction (toward the central axis O of the core back portion 22 along the radial direction). The plurality of tooth portions 23 are arranged at equal intervals in the circumferential direction. In the present embodiment, 18 tooth portions 23 are provided at every 20 degrees of the central angle centered on the central axis O. The plurality of tooth portions 23 are formed to have the same shape and the same size as each other. The shapes and sizes of the plurality of teeth portions 23 do not have to be the same.
The winding is wound around the teeth portion 23. The winding may be a centralized winding or a distributed winding.

The rotor 30 is arranged inside the stator 20 (stator core 21) in the radial direction. The rotor 30 includes a rotor core 31 and a plurality of permanent magnets 32.
The rotor core 31 is formed in an annular shape (annular ring) arranged coaxially with the stator 20. The rotating shaft 60 is arranged in the rotor core 31. The rotating shaft 60 is fixed to the rotor core 31.

The plurality of permanent magnets 32 are fixed to the rotor core 31. In this embodiment, a set of two permanent magnets 32 form one magnetic pole. The plurality of sets of permanent magnets 32 are arranged at equal intervals in the circumferential direction. In the present embodiment, 12 sets (24 in total) of permanent magnets 32 are provided at every 30 degrees of the central angle centered on the central axis O. The intervals between the plurality of sets of permanent magnets 32 do not have to be the same.

In this embodiment, an embedded magnet type motor is adopted as a permanent magnet field type electric motor. The rotor core 31 is formed with a plurality of through holes 33 that penetrate the rotor core 31 in the axial direction. The plurality of through holes 33 are provided corresponding to the plurality of permanent magnets 32. Each permanent magnet 32 is fixed to the rotor core 31 in a state of being arranged in the corresponding through hole 33. Fixing of each permanent magnet 32 to the rotor core 31 can be realized, for example, by adhering the outer surface of the permanent magnet 32 and the inner surface of the through hole 33 with an adhesive or the like. As the permanent magnet field electric motor, a surface magnet type motor may be adopted instead of the embedded magnet type motor.

Both the stator core 21 and the rotor core 31 are laminated cores. The laminated core is formed by laminating a plurality of electromagnetic steel plates 40.
The product thickness of each of the stator core 21 and the rotor core 31 is, for example, 50.0 mm. The outer diameter of the stator core 21 is, for example, 250.0 mm. The inner diameter of the stator core 21 is, for example, 165.0 mm. The outer diameter of the rotor core 31 is, for example, 163.0 mm. The inner diameter of the rotor core 31 is, for example, 30.0 mm. However, these values are examples, and the product thickness, outer diameter and inner diameter of the stator core 21, and the product thickness, outer diameter and inner diameter of the rotor core 31 are not limited to these values. Here, the inner diameter of the stator core 21 is based on the tip of the teeth portion 23 of the stator core 21. The inner diameter of the stator core 21 is the diameter of a virtual circle inscribed in the tips of all the teeth portions 23.

Each of the electromagnetic steel plates 40 forming the stator core 21 and the rotor core 31 is formed, for example, by punching an electromagnetic steel plate as a base material. As the electromagnetic steel sheet 40, a known electrical steel sheet can be used. The chemical composition of the electromagnetic steel sheet 40 is not particularly limited. In this embodiment, a non-oriented electrical steel sheet is used as the electrical steel sheet 40. As the non-oriented electrical steel sheet, for example, a non-oriented electrical steel strip of JISC2552: 2014 can be adopted. However, as the electromagnetic steel sheet 40, it is also possible to use a grain-oriented electrical steel sheet instead of the non-oriented electrical steel sheet. As the grain-oriented electrical steel sheet, for example, a grain-oriented electrical steel strip of JISC2553: 2012 can be adopted.

Insulating coatings are provided on both sides of the electrical steel sheet 40 in order to improve the workability of the electrical steel sheet and the iron loss of the laminated core. As the substance constituting the insulating film, for example, (1) an inorganic compound, (2) an organic resin, (3) a mixture of an inorganic compound and an organic resin, and the like can be applied. Examples of the inorganic compound include (1) a complex of dichromate and boric acid, and (2) a complex of phosphate and silica. Examples of the organic resin include epoxy-based resin, acrylic-based resin, acrylic styrene-based resin, polyester-based resin, silicon-based resin, and fluorine-based resin.

In order to ensure the insulating performance between the electromagnetic steel sheets 40 laminated with each other, the thickness of the insulating film (thickness per one side of the electromagnetic steel sheet 40) is preferably 0.1 μm or more.
On the other hand, as the insulating film becomes thicker, the insulating effect saturates. Further, as the insulating film becomes thicker, the space factor decreases, and the performance as a laminated core deteriorates. Therefore, the insulating coating should be as thin as possible to ensure the insulating performance. The thickness of the insulating film (thickness per one side of the electromagnetic steel sheet 40) is preferably 0.1 μm or more and 5 μm or less, and more preferably 0.1 μm or more and 2 μm or less.

As the electromagnetic steel sheet 40 becomes thinner, the effect of improving iron loss gradually saturates. Further, as the electromagnetic steel sheet 40 becomes thinner, the manufacturing cost of the electrical steel sheet 40 increases. Therefore, the thickness of the electrical steel sheet 40 is preferably 0.10 mm or more in consideration of the effect of improving iron loss and the manufacturing cost.
On the other hand, if the electromagnetic steel sheet 40 is too thick, it becomes difficult to punch the electrical steel sheet 40 by pressing. Therefore, considering the punching process of the electrical steel sheet 40, the thickness of the electrical steel sheet 40 is preferably 0.65 mm or less.
Further, as the electromagnetic steel sheet 40 becomes thicker, the iron loss increases. Therefore, considering the iron loss characteristics of the electrical steel sheet 40, the thickness of the electrical steel sheet 40 is preferably 0.35 mm or less, more preferably 0.20 mm or 0.25 mm.
In consideration of the above points, the thickness of each electrical steel sheet 40 is, for example, 0.10 mm or more and 0.65 mm or less, preferably 0.10 mm or more and 0.35 mm or less, and more preferably 0.20 mm or 0.25 mm. is there. The thickness of the electromagnetic steel sheet 40 includes the thickness of the insulating film.

In the stator core 21 of the present embodiment, all the sets of the electromagnetic steel plates 40 adjacent to each other in the stacking direction are joined by either bonding or caulking. The stator core 21 includes a first set in which the electromagnetic steel sheets 40 are not crimped and bonded to each other, and a second set in which the electromagnetic steel sheets 40 are bonded and not bonded to each other.
In the present invention, the first set included in the laminated core may be one or two or more. The second set included in the laminated core may be one or two or more.

As shown in FIG. 3, in the present embodiment, among the plurality of electromagnetic steel sheets 40, the N1 electrical steel sheets 40 located on the first side D1 along the stacking direction and the second side D2 along the stacking direction are located. None of the N2 electrical steel sheets 40 are crimped and bonded to each other, and are not joined by a joining method other than crimping. Of the plurality of electrical steel sheets 40, the N3 electrical steel sheets 40 located at the center along the stacking direction are not bonded to each other and are not bonded by a joining method other than bonding.

As described above, the second set in which the N3 electrical steel sheets 40 are not bonded and crimped is the first set in which the N1 electrical steel sheets 40 are not bonded and bonded to each other, and the N2 electrical steel sheets 40 are not bonded to each other. It is sandwiched from both sides in the stacking direction by a first set that is not crimped and bonded to each other. The N3 magnetic steel sheets 40 form the central portion 21c of the stator core 21. Assuming that the total number of electrical steel sheets 40 is N0, N0 is obtained as the sum of N1, N2, and N3.

Of both ends of the stator core 21 in the stacking direction, the end located on the first side D1 is referred to as the first end 21a, and the end located on the second side D2 is referred to as the second end 21b. The first end portion 21a is formed of N1 sheet of electromagnetic steel plate 40. The second end portion 21b is formed of N2 magnetic steel plates 40. In this embodiment, N1 and N2 are equal. Here, the equality of N1 and N2 includes not only the case where N1 and N2 are completely equal, but also the case where there is a slight difference between N1 and N2 (substantially equal). This slight difference means a difference in the number of sheets within 5% with respect to the total number of sheets of the stator core 21.

As shown in FIG. 4, caulking C1 and C2 are formed on the electromagnetic steel sheets 40 (each of N1 and N2 electrical steel sheets 40) that are crimped to each other. The caulking C1 and C2 include a first caulking C1 provided on the core back portion 22 and a second caulking C2 provided on the teeth portion 23.

A plurality of first caulking C1s are arranged at equal intervals along the circumferential direction. In the illustrated example, the first caulking C1 is arranged so as to be offset from the teeth portion 23 along the circumferential direction. The first caulking C1 is arranged in the middle of the adjacent teeth portions 23 along the circumferential direction. The first caulking C1 is arranged at the center of the core back portion 22 along the radial direction. The second caulking C2 is provided in all the teeth portions 23. The second caulking C2 is arranged at the center of each tooth portion 23 in the circumferential direction. Two second caulking C2s are arranged side by side in the radial direction on each tooth portion 23.

As shown in FIG. 5A, the first caulking C1 has a caulking convex portion C11 in which a part of a steel plate is bent in a U shape and protrudes to the first side D1, and a second caulking convex portion C11. It is provided with a groove-shaped caulking recess C12 formed on the side D2. In the core back portions 22 of the electromagnetic steel plates 40 that are crimped to each other, the convex portions C11 for caulking the first caulking C1 of the electromagnetic steel plate 40 on the second side D2 are the first caulking C1 of the electromagnetic steel plate 40 on the first side D1. It is crimped by being fitted into the caulking recess C12.

The second caulking C2 has the same form as the first caulking C1, and as shown in FIG. 5 (B), the caulking convex portion C21 protruding to the first side D1 and the second side of the caulking convex portion C21. It is provided with a groove-shaped caulking recess C22 formed in D2. In the teeth portions 23 of the electromagnetic steel plates 40 that are crimped to each other, the convex portions C21 for caulking of the second caulking C2 of the electromagnetic steel plate 40 on the second side D2 are the second caulking C2 of the electromagnetic steel plate 40 on the first side D1. It is crimped by being fitted into the caulking recess C22.

At the boundary portion M1 between the first set in which the N2 electrical steel sheets 40 are not crimped and bonded to each other and the second set in which the N3 electrical steel sheets 40 are not bonded and bonded to each other, one of the electrical steel sheets is used. The caulking protrusions C11 and C21 are provided on the 40, and the other electromagnetic steel sheet 40 is not provided with the caulking. The electromagnetic steel sheets 40 at the boundary portion M1 are adhered to each other with an adhesive having an SP value of 7.8 to 10.7 (cal / cm ³ ) ^1/2 (hereinafter referred to as an adhesive (X)). Further, at the boundary portion M2 between the first set in which the N1 electrical steel sheets 40 are not crimped and bonded to each other and the second set in which the N3 electrical steel sheets 40 are not bonded and bonded to each other, one of them is formed. The electromagnetic steel sheet 40 is provided with caulking recesses C12 and C22, and the other electrical steel sheet 40 is not provided with caulking. The electromagnetic steel plates 40 at the boundary portion M2 are also bonded to each other with an adhesive (X).
The electromagnetic steel sheets 40 at the boundary portions M1 and M2 are locally bonded to each other.

In this example, as shown in FIG. 5A, an adhesive portion 50 made of an adhesive (X) is provided at the tip of the caulking convex portion C11 of the first caulking C1 at the boundary portion M1. As a result, the tip of the caulking convex portion C11 is adhered to the surface of the second set of electromagnetic steel sheets 40 on the first caulking C1 side (second side D2) by the adhesive portion 50. Similarly, as shown in FIG. 5 (B), an adhesive portion 52 made of an adhesive (X) is provided at the tip of the caulking convex portion C21 of the second caulking C2. As a result, the tip of the caulking convex portion C21 is adhered to the surface of the second set of electromagnetic steel sheets 40 on the second caulking C2 side (second side D2) by the adhesive portion 52.
The adhesive portions 50 and 52 are a series of adhesives (X) that are cured without being divided.

In the present embodiment, since the adhesive portion 50 made of the adhesive (X) is provided at the tip of the caulking convex portion C11, the adhesive portion 50 at the boundary portion M1 has the same circumference as the first caulking C1 in a plan view. It is provided in dots on the top. Similarly, since the adhesive portion 52 made of the adhesive (X) is provided at the tip of the caulking convex portion C21, the adhesive portion 52 at the boundary portion M1 is on the same circumference as the second caulking C2 in a plan view. It is provided in dots.
In the present invention, it is preferable that the adhesive portion made of the adhesive (X) for adhering the electromagnetic steel plates to each other at the boundary portion is provided in a dot shape on the same circumference as the caulking of the boundary portion in a plan view. .. As a result, the adhesive strength between the electromagnetic steel sheets at the boundary portion becomes sufficiently high, and the magnetic characteristics are improved.

The thickness of the adhesive portions 50 and 52 at the boundary portion M1 is preferably 1 μm or more in order to obtain stable and sufficient adhesive strength. On the other hand, when the thickness of the adhesive portions 50 and 52 exceeds 100 μm, the adhesive force is saturated. Further, as the adhesive portions 50 and 52 become thicker, the space factor decreases, and the torque density when the laminated core is used as a motor decreases. Therefore, the thickness of the bonded portions 50 and 52 is preferably 1 μm or more and 100 μm or less, more preferably 1 μm or more and 10 μm or less.

The mode in which the adhesive portion is provided in a point shape on the same circumference as the caulking in a plan view at the boundary portion is not limited to the above-described mode. For example, at the boundary portion, at least a part of the portion other than the caulking of the first set of electromagnetic steel sheets may be adhered to the surface of the second set of electromagnetic steel sheets on the caulking side with an adhesive (X).

Specifically, for example, the embodiment illustrated in FIG. 6 may be used. In this example, in the core back portion 22 of the first set of electromagnetic steel sheets 40 at the boundary portion M1, the adhesive portion 54 made of the adhesive (X) is on the same circumference as the first caulking C1 in a plan view. It is provided in a dot shape between 1 caulking C1. Further, in each tooth portion 23, adhesive portions 56 made of an adhesive (X) are provided in dots on both sides of each second caulking C2 on the same circumference as the second caulking C2 in a plan view.
The adhesive portions 54 and 56 are a series of adhesives (X) that are cured without being divided.

In the case of this aspect, as shown in FIG. 7A, the thickness of the adhesive portion 54 made of the adhesive (X) at the boundary portion M1 in the stacking direction is the thickness of the caulking convex portion C11 of the first caulking C1. Same as height. Similarly, as shown in FIG. 7B, the thickness of the adhesive portion 56 made of the adhesive (X) at the boundary portion M1 in the stacking direction is the same as the height of the caulking convex portion C21 of the second caulking C2. To do. As a result, the electromagnetic steel plates 40 can be firmly bonded to each other by the bonding portions 54 and 56 at the boundary portion M1.

As shown in FIG. 8A, in the boundary portion M2, on the surface of the first side D1 of the core back portion 22 of the second set of electrical steel sheets 40 in which the N3 electrical steel sheets 40 are not adhered to each other and crimped. The adhesive portion 58 made of the adhesive (X) is provided in a dot shape between the first caulking C1 and each first caulking C1 on the same circumference in a plan view. Further, as shown in FIG. 8B, the adhesive (on the surface of the first side D1 of the teeth portion 23 of the second set of electrical steel sheets 40 in which the N3 electrical steel sheets 40 are not adhered and crimped) Adhesive portions 60 made of X) are provided in dots at positions on both sides of each second caulking C2 on the same circumference as the second caulking C2 in a plan view. Also in the boundary portion M2, the adhesive portion made of the adhesive (X) is provided in a dot shape on the same circumference as the caulking of the boundary portion in a plan view, so that the adhesive strength between the electromagnetic steel sheets is sufficiently high. Therefore, the magnetic characteristics are improved.
The adhesive portions 58 and 60 are a series of adhesives (X) that are cured without being divided.

The thickness of the adhesive portions 58 and 60 at the boundary portion M2 is preferably 1 μm or more in order to obtain stable and sufficient adhesive strength. On the other hand, when the thickness of the adhesive portions 58 and 60 exceeds 100 μm, the adhesive force is saturated. Further, as the adhesive portions 58 and 60 become thicker, the space factor decreases, and the torque density when the laminated core is used as a motor decreases. Therefore, the thickness of the bonded portions 58 and 60 is preferably 1 μm or more and 100 μm or less, more preferably 1 μm or more and 10 μm or less.

The adhesive (X) is an adhesive having an SP value of 7.8 to 10.7 (cal / cm ³ ) ^1/2 . The SP value means a solubility parameter defined by Hildebrand.
Since the punching oil is used for the punching process of the electromagnetic steel sheet, the punching oil remains on the laminated surface of the electromagnetic steel sheet 40 at the time of laminating. Since the punching oil remaining on the laminated surface of the electromagnetic steel sheet 40 is interposed between the laminated surface of the electromagnetic steel sheet and the adhesive, it tends to hinder the adhesion between the electromagnetic steel sheets 40 by the adhesive. At the boundary portion M1 and the boundary portion M2, particularly at the boundary portion M1, there is a high tendency that it becomes difficult to bond the electromagnetic steel sheets 40 to each other with an adhesive. In addition, the punching oil is absorbed and diffused in the adhesive during manufacturing.

The SP value of the punching oil is known to be 7.3 to 7.8 (cal / cm ³ ) ^1/2 . The adhesive (X) having an SP value in the range of 7.8 to 10.7 (cal / cm ³ ) ^1/2 is excellent in compatibility with punching oil, and therefore is excellent in laminating electromagnetic steel sheets after punching. It develops oil level adhesiveness. Therefore, the electromagnetic steel sheets 40 are bonded to each other with high adhesive strength at the boundary portions M1 and M2.
The SP value of the adhesive (X) is preferably 7.8 to 10.0 (cal / cm ³ ) ^1/2 , preferably 8.1 to 8.7 (cal / cm), from the viewpoint of improving the oil level adhesiveness. ³ ) ^1/2 is more preferable.

In order to obtain an adhesive (X) having excellent compatibility with punching oil and easily exhibiting oil level adhesiveness, it is preferable that the difference between the SP value of the punching oil and the SP value of the adhesive (X) is small. On the other hand, since the oil taken into the adhesive acts as a plasticizer, there is no problem if the amount is small, but if the amount is large, the adhesive strength tends to decrease. Further, if the amount of oil taken in is too large, the degree of swelling of the adhesive increases, and the amount of punched oil adhered becomes non-uniform, which may cause a dimensional error.
Absolute value of the difference from these viewpoints, the SP value of the punching oil used in the punching ([delta] _oil) and adhesive SP value of (X) and _{(δ X) (| δ oil} -δ X |) is 0 .1 to 2.3 (cal / cm ³ ) ^1/2 is preferable, and 0.3 to 1.0 (cal / cm ³ ) ^1/2 is more preferable. When | δ _{oil −} δ _X | is within the above range, the adhesive strength between the electromagnetic steel sheets 40 is further improved at the boundary portions M1 and M2, and the reliability of the laminated core is improved.

The SP value of the adhesive (X) can be adjusted, for example, by blending an additive. For example, when the adhesive (X) is an epoxy resin adhesive, an additive having a smaller SP value, that is, a lower polarity than the epoxy resin (SP value: about 10.9 (cal / cm ³ ) ^1/2 ) is used. The SP value of the adhesive (X) can be reduced by blending.

The additive for adjusting the SP value of the adhesive (X) may be any additive that does not affect the adhesiveness of the adhesive (X) or the performance of the rotary electric machine. For example, acetone (SP value: 9.9 (cal)). / Cm ³ ) ^1/2 ), acetic acid (10.1 (cal / cm ³ ) ^1/2 ) and the like can be exemplified. Further, it is also possible to reduce the SP value of the adhesive (X) by blending a synthetic rubber having a small SP value, which will be described later. The additive to be blended in the adhesive (X) may be one kind or two or more kinds.

Examples of the adhesive (X) include an epoxy resin-based adhesive containing an epoxy resin as a main component and an acrylic resin-based adhesive containing an acrylic resin as a main component. In addition, "the main component is an epoxy resin" means that the ratio of the epoxy resin to the total mass of the main agent (component other than the curing agent) of the adhesive is 50% by mass or more. Similarly, "mainly composed of acrylic resin" means that the ratio of acrylic resin to the total mass of the main agent (component other than the curing agent) of the adhesive is 50% by mass or more. When the epoxy resin-based adhesive contains an acrylic resin, the ratio of the acrylic resin to the total mass of the main component of the epoxy resin-based adhesive is 50% by mass or less. When the acrylic resin-based adhesive contains an epoxy resin, the ratio of the epoxy resin to the total mass of the main component of the acrylic resin-based adhesive is less than 50% by mass. As the adhesive (X), an epoxy resin-based adhesive is preferable from the viewpoint of excellent heat resistance and adhesiveness.

The epoxy resin-based adhesive includes an epoxy resin and a curing agent. An epoxy resin-based adhesive further containing an acrylic resin in addition to the epoxy resin and the curing agent is preferable from the viewpoint of excellent heat resistance, quick-curing property, and oil surface adhesiveness. An epoxy resin-based adhesive containing an acrylic-modified epoxy resin obtained by graft-polymerizing an acrylic resin on an epoxy resin may be used.
The acrylic resin-based adhesive preferably further contains an epoxy resin and a curing agent.

The epoxy resin is not particularly limited, and examples thereof include bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol AD type epoxy resin, glycidylamine type epoxy resin, and alicyclic epoxy resin. Of these, the bisphenol F type epoxy resin is preferable because of its low viscosity and excellent workability. The epoxy resin contained in the epoxy resin-based adhesive may be one type or two or more types.

The glass transition temperature (Tg) of the epoxy resin is preferably 80 to 150 ° C., more preferably 100 to 150 ° C., and even more preferably 120 to 150 ° C. When the Tg of the epoxy resin is at least the lower limit of the above range, a laminated core having excellent heat resistance and high mechanical strength can be easily obtained. When the Tg of the epoxy resin is not more than the upper limit of the above range, the adhesion with the steel sheet can be easily obtained.
The Tg of the epoxy resin is the intermediate point glass transition temperature measured by the differential scanning calorimetry (DSC) method according to JISK7121-1987.

The number average molecular weight (Mn) of the epoxy resin is preferably 1200 to 20000, more preferably 2000 to 18000, and even more preferably 2500 to 16000. When the Mn of the epoxy resin is at least the lower limit of the above range, the adhesive strength can be easily increased. When the Mn of the epoxy resin is not more than the upper limit of the above range, it is easy to prevent the epoxy resin adhesive from becoming highly viscous.
The Mn of the epoxy resin can be measured by size exclusion chromatography (SEC: Size-Exclusion Chromatography) described in JIS K7252-1: 2008 using polystyrene as a standard substance.

The curing agent is not particularly limited, and a generally used epoxy resin curing agent can be used. The curing agent may be a low temperature or room temperature curing type, or may be a heat curing type. Specific examples of the curing agent include aliphatic polyamines, aromatic polyamines, acid anhydrides, phenol novolac resins, organophosphorus compounds, and dicyandiamide (DICY). The curing agent contained in the epoxy resin adhesive may be one type or two or more types.

Examples of the aliphatic polyamine include triethylenetetramine, diethylenetriamine (DTA), and diethylaminopropylamine (DEAPA).
Examples of the aromatic polyamine include diaminodiphenylmethane (DDM), metaphenylenediamine (MPDA), and diaminodiphenyl sulfone (DDS).
Examples of the acid anhydride include phthalic acid anhydride, hexahydrophthalic acid anhydride, and 4-methylhexahydrophthalic acid anhydride.

The phenol novolac resin is a novolak type phenol resin obtained by subjecting phenols (phenols and the like) and aldehydes (formaldehyde and the like) to a condensation reaction using an acid catalyst.

The organic phosphorus compound is not particularly limited, and is, for example, hexamethylphosphate triamide, triphosphate (dichloropropyl), triphosphate (chloropropyl), triphenylphosphine, trimethylphosphate, phenylphosphonic acid, triphenyl. Examples thereof include phosphine, tri-n-butylphosphine, and diphenylphosphine.

As the curing agent, a heat-curing type curing agent is preferable from the viewpoint of excellent heat resistance, a phenol novolac resin and an aromatic polyamine are more preferable, and a phenol novolac resin is particularly preferable from the viewpoint that a stator core having high mechanical strength can be easily obtained. .. When two or more kinds of epoxy resin curing agents are used, for example, an embodiment in which a phenol novolac resin is used as a main component and an aromatic polyamine is blended can be mentioned.

The content of the curing agent in the epoxy resin adhesive can be appropriately set according to the type of the curing agent. For example, when a phenol novolac resin is used, it is preferably 5 to 35 parts by mass with respect to 100 parts by mass of the epoxy resin.

A curing accelerator may be added to the epoxy resin-based adhesive and the acrylic resin-based adhesive containing the epoxy resin. Examples of the curing accelerator include tertiary amines, secondary amines, and imidazoles. The curing accelerator contained in the epoxy resin adhesive may be one kind or two or more kinds.

The acrylic resin is not particularly limited. Examples of the monomer used for the acrylic resin include unsaturated carboxylic acids such as acrylic acid and methacrylic acid, methyl (meth) acrylate, ethyl (meth) acrylate, n-butyl (meth) acrylate, isobutyl (meth) acrylate, and cyclohexyl (meth). Examples thereof include (meth) acrylates such as meta) acrylates, 2-ethylhexyl (meth) acrylates, 2-hydroxyethyl (meth) acrylates, and hydroxypropyl (meth) acrylates. The (meth) acrylate means acrylate or methacrylate. The acrylic resin contained in the adhesive (X) may be one type or two or more types.
When an acrylic resin is used as the adhesive, it may be contained as a monomer forming the acrylic resin in the adhesive before curing.

The number average molecular weight (Mn) of the acrylic resin is preferably 5,000 to 100,000, more preferably 6,000 to 80,000, and even more preferably 7,000 to 60,000. When the Mn of the acrylic resin is at least the lower limit of the above range, the adhesive strength can be easily increased. When Mn of the acrylic resin is not more than the upper limit of the above range, it is easy to prevent the adhesive (X) from becoming highly viscous.
The Mn of the acrylic resin can be measured by the same method as the Mn of the epoxy resin.

When the epoxy resin-based adhesive contains an acrylic resin, for example, it can be 20 to 50% by mass with respect to the total mass of the main agent of the epoxy resin-based adhesive. In the case of an acrylic resin-based adhesive containing an epoxy resin, for example, the ratio of the epoxy resin is less than 50% by mass and the ratio of the acrylic resin is 50 to 80% by mass with respect to the total mass of the main component of the acrylic resin-based adhesive. To do.

The epoxy resin-based adhesive and the acrylic resin-based adhesive containing the epoxy resin may contain an elastomer. By blending an elastomer, the tensile elastic modulus of the bonded portion can be controlled within a specific range, which contributes to the improvement of viscosity and flow characteristics.
Examples of the elastomer include natural rubber and synthetic rubber, and synthetic rubber is preferable. The elastomer contained in the epoxy resin adhesive may be one type or two or more types.

Examples of the synthetic rubber include polybutadiene synthetic rubber, nitrile synthetic rubber, and chloroprene synthetic rubber.
Examples of the polybutadiene synthetic rubber include isoprene rubber (IR), butadiene rubber (BR), styrene butadiene rubber (SBR), polyisobutylene (butyl rubber, IIR), and ethylene propylene diene rubber (EPDM). Examples of the nitrile-based synthetic rubber include acrylonitrile butadiene rubber (NBR) and acrylic rubber (ACM). As the chloroprene-based synthetic rubber, chloroprene rubber (CR) can be exemplified.

EPDM (SP value: 7.9 to 8.0 (cal / cm ³ ) ^1/2 ), SBR (SP value: 8.1 to 8.7 (cal / cm ³ ) ^1/2 ), BR (SP value : 8.1-8.6 (cal / cm ³ ) ^1/2 ), NBR (SP value: 8.7 to 10.5 (cal / cm ³ ) ^1/2 )) has a higher SP value than epoxy resins. The small elastomer can also be used for the purpose of adjusting the SP value of the adhesive (X). By using such an elastomer, the tensile elastic modulus can be controlled while improving the oil level adhesion.

Preferred epoxy resin-based adhesives include an adhesive containing an epoxy resin and a phenol novolac resin, an adhesive containing an epoxy resin, a phenol novolac resin and an acrylic resin, and an epoxy resin having a Tg of 120 to 180 ° C. and an organic phosphorus compound. An example of an adhesive containing an epoxy resin, an epoxy resin, an epoxy resin curing agent, and an elastomer.

When the adhesive portion 50 is formed of an epoxy resin adhesive containing an epoxy resin having a Tg of 120 to 180 ° C. and an elastomer, the adhesive portion 50 has a room temperature tensile elastic modulus of 1500 to 5000 MPa and has a tensile elasticity at 150 ° C. The rate is preferably 1000 to 3000 MPa.
The normal temperature tensile elastic modulus of the bonded portion 50 is preferably 1500 to 5000 MPa, more preferably 1500 to 4000 MPa. When the normal temperature tensile elastic modulus is at least the lower limit of the above range, the iron loss characteristic of the laminated core is excellent. When the normal temperature tensile elastic modulus is not more than the upper limit of the above range, the bonding strength of the laminated core is excellent.
The normal temperature tensile elastic modulus is a value measured at 25 ° C. by the resonance method. Specifically, the tensile elastic modulus is measured in accordance with JIS R 1602: 1995.

The tensile elastic modulus of the bonded portion 50 at 150 ° C. is preferably 1000 to 3000 MPa, more preferably 1000 to 2800 MPa, and even more preferably 1000 to 2500. When the tensile elastic modulus at 150 ° C. is equal to or higher than the lower limit of the above range, the bonding strength of the laminated core is excellent. When the tensile elastic modulus at 150 ° C. is not more than the upper limit of the above range, the iron loss characteristic of the laminated core is excellent.
The tensile elastic modulus at 150 ° C. is a value measured at 150 ° C. by the resonance method. The tensile elastic modulus at 150 ° C. is measured by the same method as the room temperature tensile elastic modulus except for the measurement temperature.
The normal temperature tensile elastic modulus of the bonded portions 52, 54, 56, 58, 60 and the tensile elastic modulus at 150 ° C. are preferably in the same range as that of the bonded portion 50.

The average diameter of the bonded portions 50, 52, 54, 56, 58, 60 is preferably 2 to 20 mm, more preferably 2 to 15 mm. In the case of the stator core, the average diameter of the point-shaped adhesive portion provided on the tooth portion is more preferably 3 to 7 mm, and the average diameter of the dot-shaped adhesive portion provided on the core back portion is more preferably 5 to 10 mm.
The average diameter is obtained by measuring the diameter of the adhesive trace of the adhesive portion where the electromagnetic steel sheets 40 are peeled off with a ruler. If the plan view shape of the adhesive trace is not a perfect circle, its diameter shall be the diameter of the circumscribed circle (perfect circle) of the adhesive trace in a plan view.

The adhesive area ratio of the electromagnetic steel sheet 40 by the adhesive portion at the boundary portions M1 and M2 is preferably 1% or more and 40% or less, and more preferably 1% or more and 20% or less, respectively. The adhesive area ratio of the electromagnetic steel sheet 40 by the adhesive portion is that the adhesive portion of the first surface is provided with respect to the area of the surface of the electromagnetic steel sheet 40 facing the stacking direction (hereinafter, referred to as the first surface of the electromagnetic steel sheet 40). It is the ratio of the area of the area (adhesion area). The region provided with the adhesive portion is a region (adhesive region) of the first surface of the electrical steel sheet 40 in which a series of adhesives cured without being divided are provided. The area of the region where the adhesive portion is provided can be obtained, for example, by photographing the first surface of the magnetic steel sheet 40 after peeling and analyzing the imaged result.

The N3 magnetic steel sheets 40 are adhered to each other by the adhesive portion 41. The adhesive portion 41 is a series of adhesives provided between N3 magnetic steel sheets 40 adjacent to each other in the stacking direction and cured without being divided. The adhesive (X) is preferable as the adhesive for forming the adhesive portion 41.
As shown in FIG. 9, the electromagnetic steel sheets 40 adjacent to each other in the stacking direction bonded by the bonding portion 41 are not completely bonded to each other. These electromagnetic steel sheets 40 are locally bonded to each other.

In the present embodiment, the electromagnetic steel sheets 40 adjacent to each other in the stacking direction are adhered to each other by an adhesive portion 41 provided along the peripheral edge of the electromagnetic steel sheet 40. Specifically, the electromagnetic steel sheets 40 adjacent to each other in the stacking direction are electromagnetically connected to the first adhesive portion 41a provided along the outer peripheral edge of the electromagnetic steel sheets 40 in a plan view of the electromagnetic steel sheets 40 viewed from the stacking direction. It is adhered by a second adhesive portion 41b provided along the inner peripheral edge of the steel plate 40. The first and second adhesive portions 41a and 41b are each formed in a strip shape in a plan view.

Here, the band shape also includes a shape in which the width of the band changes in the middle. For example, a shape in which round points are continuous in one direction without being divided is also included in a band shape extending in one direction. Further, along the peripheral edge includes not only the case where it is completely parallel to the peripheral edge but also the case where it has an inclination of, for example, 5 degrees or less with respect to the peripheral edge.

The first adhesive portion 41a is arranged along the outer peripheral edge of the electromagnetic steel sheet 40. The first adhesive portion 41a extends continuously over the entire circumference in the circumferential direction. The first adhesive portion 41a is formed in an annular shape in a plan view of the first adhesive portion 41a when viewed from the stacking direction.
The second adhesive portion 41b is arranged along the inner peripheral edge of the electromagnetic steel sheet 40. The second adhesive portion 41b extends continuously over the entire circumference in the circumferential direction.

The second adhesive portion 41b connects a plurality of tooth portions 44 arranged at intervals in the circumferential direction and arranged in each tooth portion 23 and tooth portions 44 arranged in the core back portion 22 and adjacent to each other in the circumferential direction. It is provided with a plurality of core back portions 45 and the like.
The tooth portion 44 includes a pair of first portions 44a that are arranged at intervals in the circumferential direction and extend along the radial direction, and a second portion 44b that connects the pair of first portions 44a to each other in the circumferential direction. There is. The first portion 44a extends in a radial direction in a strip shape. The second portion 44b extends in a band shape in the circumferential direction.

In the present embodiment, the plan-view shapes of all the adhesive portions 41 provided between the electromagnetic steel plates 40 are the same. The plan view shape of the adhesive portion 41 means the overall shape of the adhesive portion 41 in the plan view of the electromagnetic steel sheet 40 provided with the adhesive portion 41 in the stacking direction. The fact that all the adhesive portions 41 provided between the electromagnetic steel sheets 40 have the same plan view shape means that the plan view shapes of all the adhesive portions 41 provided between the electromagnetic steel plates 40 are completely the same. It does not include only a certain case, but also includes a case where all the adhesive portions 41 provided between the electromagnetic steel sheets 40 have substantially the same planological shape in 95% or more of the portions.

The adhesive area ratio of the electromagnetic steel sheet 40 by the adhesive portion 41 is preferably 1% or more and 40% or less, and more preferably 1% or more and 20% or less. The adhesive area ratio of the electromagnetic steel sheet 40 by the adhesive portion 41 is the adhesive portion 41 of the first surface of the electromagnetic steel plate 40 with respect to the area of the surface facing the stacking direction (hereinafter referred to as the first surface of the electromagnetic steel sheet 40). Is the ratio of the area of the region (adhesive region 42) provided with. The region provided with the adhesive portion 41 is a region (adhesive region 42) of the first surface of the electrical steel sheet 40 provided with a series of adhesives cured without being divided. The area of the region where the adhesive portion 41 is provided can be obtained, for example, by photographing the first surface of the magnetic steel sheet 40 after peeling and analyzing the imaged result.

In the present embodiment, the caulking C1 and C2 and the adhesive portion 41 are arranged at positions where they do not overlap in a plan view and avoid each other. The caulking C1 and C2 and the adhesive portion 41 are arranged so as to be offset in a plan view. The total area of caulking C1 and C2 in a plan view is smaller than the total area of the bonded portion 41.

In the present embodiment, the plurality of electromagnetic steel plates 40 forming the rotor core 31 are fixed to each other by caulking C (dowels). However, the plurality of electromagnetic steel plates 40 forming the rotor core 31 may be adhered to each other by the adhesive portion 41. The rotor core 31 may be formed by so-called rotating stacking.

(Manufacturing method of laminated core)
Hereinafter, a method for manufacturing a laminated core according to an embodiment of the present invention will be described. In the laminated core of the present invention, an adhesive (X) is applied to either or both of the first set of electromagnetic steel sheets and the second set of electromagnetic steel sheets, and the layers are cured to bond the electromagnetic steel sheets to each other. , Can be produced by a known method.

For example, the following method can be mentioned.
The electromagnetic steel sheet 40 can be manufactured by punching a plurality of times using punching oil while feeding the electromagnetic steel sheet from a coil (hoop) in a predetermined direction.
N2 electrical steel sheets 40 having the first caulking C1 and the second caulking C2 are joined and laminated by caulking. At the boundary portion M1, the tip of the first caulking convex portion C11 and the tip of the second caulking convex portion C21 of the top electromagnetic steel sheet 40 of the first set in which the N2 magnetic steel sheets 40 are not crimped and adhered to each other. The adhesive (X) is applied to the product, or the adhesive (X) is applied in the pattern illustrated in FIG. 6, and then the electromagnetic steel sheets 40 having no caulking are laminated and crimped. When the adhesive (X) is a heat-curable type, it is heated to 150 to 160 ° C. to accelerate curing.

Next, the adhesive (X) is applied to the upper surface of the top electromagnetic steel sheet 40 in the pattern illustrated in FIG. 9, and the operation of stacking and crimping the electromagnetic steel sheets 40 having no caulking is repeated, and the N3 magnetic steel sheets 40 are put together. Laminate a second set that is glued to each other and not crimped. When the adhesive (X) is a heat-curable type, it is heated to 150 to 160 ° C. to accelerate curing.

Further, in the boundary portion M2, an adhesive having a pattern similar to the pattern illustrated in FIG. 6 is applied to the upper surface of the top electromagnetic steel sheet 40 of the second set in which the N3 magnetic steel sheets 40 are not bonded to each other and crimped to each other. After applying (X), the electromagnetic steel sheets 40 having the first caulking C1 and the second caulking C2 are overlapped and crimped. The operation of joining and laminating the electromagnetic steel sheets 40 having the first caulking C1 and the second caulking C2 by caulking is repeated, and the first set in which the N1 electromagnetic steel sheets 40 are crimped and not adhered is laminated. When the adhesive (X) is a heat-curable type, it is heated to 150 to 160 ° C. to accelerate curing.
The stator core 21 is completed by the above steps.

In the present invention, when the adhesive (X) is applied to at least a part of the boundary portion other than the caulking of the first set of electrical steel sheets as in the coating pattern illustrated in FIG. 6, the adhesive (X) is applied at the coating stage. It is preferable to apply the adhesive (X) so as to be thicker than the height of the caulking convex portion of the caulking. Then, the adhesive (X) is cured in a state where the tip of the crimping convex portion is in contact with the second set of electromagnetic steel sheets, and the adhesive portion has the same thickness as the height of the caulking convex portion. It is preferable to bond the electromagnetic steel sheets of the above. This makes it easy to firmly bond the electromagnetic steel sheets to each other at the boundary portion.

As the adhesive (X), the absolute value of the difference in SP value from the punching oil is 0.1 to 0.3 (from the viewpoint that the adhesive strength between the electromagnetic steel plates is further improved and the reliability of the laminated core is improved. cal / cm ³ ) It is preferable to use one that is ^1/2 .

As described above, in the present invention, in the laminated core, the electromagnetic steel plates at the boundary between the first set and the second set are bonded to each other with the adhesive (X). As a result, the adhesive strength between the electromagnetic steel sheets is increased at the boundary portion, so that the mechanical strength is high and the laminated core has low noise and vibration.

Further, the joining by caulking can improve the dimensional accuracy as compared with the joining by adhesion. On the other hand, bonding by bonding can suppress distortion generated in electrical steel sheets as compared with bonding by caulking. Since the strain generated in the electrical steel sheet affects the iron loss of the electrical steel sheet and the magnetic characteristics of the laminated core, it is preferable that the strain is small. Since the laminated core in the present invention combines bonding by caulking and bonding by adhesion, it is possible to achieve both dimensional accuracy of the outer shape and magnetic characteristics.

In the mode in which the second set is sandwiched by the first set from both sides in the stacking direction as in the stator core 21, the dimensional accuracy of the outer shape and the magnetic characteristics can be more highly compatible. Further, when the ratio of the number of electrical steel sheets joined by caulking is low (for example, N3> N1 + N2), the magnetic characteristics can be further improved. If N1 = N2, the dimensional accuracy is further improved and the handleability is improved.

The technical scope of the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the spirit of the present invention.

The shape of the stator core is not limited to the form shown in the above embodiment. Specifically, the dimensions of the outer diameter and inner diameter of the stator core, the product thickness, the number of slots, the dimensional ratio between the circumferential direction and the radial direction of the teeth portion 23, the dimensional ratio in the radial direction between the teeth portion 23 and the core back portion 22, etc. Can be arbitrarily designed according to the desired characteristics of the rotating electric machine.

The laminated core is not limited to a mode in which the second set is sandwiched by the first set from both sides in the stacking direction. For example, a plurality of electrical steel sheets may be bonded in one or more sets in the stacking direction, specifically in every set of prime numbers (at least in the present specification, the prime number includes 1). As a specific example, a plurality of electrical steel sheets may be bonded to every other set (every two sheets) in the stacking direction and crimped to every other set (every two sheets). A plurality of electrical steel sheets may be bonded to every two sets (every three sheets) in the stacking direction and crimped to every two sets (every three sheets). In such an embodiment, both the dimensional accuracy of the outer shape and the magnetic characteristics can be compatible.

At the boundary portion, the adhesive portion made of the adhesive (X) does not have to be provided on the same circumference as the caulking in a plan view. For example, as shown in FIG. 10, a point-like adhesive portion 54 is provided at a boundary portion between each first caulking C1 in the core back portion 22 and each tooth portion 23, and each tooth portion 23 is provided with a point-like adhesive portion 54. 2 Adhesive portions 56 may be provided on the inner and outer sides of the caulking C2 in the radial direction, respectively.
The adhesive portion made of the adhesive (X) does not have to be dotted. For example, at the boundary portion, the adhesive portion made of the adhesive (X) may be formed in the manner shown in the adhesive portion 41 of FIG.

In the rotor of the above embodiment, a set of two permanent magnets 32 form one magnetic pole, but the present invention is not limited to this. For example, one permanent magnet 32 may form one magnetic pole, or three or more permanent magnets 32 may form one magnetic pole.

In the above-described embodiment, the permanent magnet field type electric motor has been described as an example of the rotary electric machine, but the structure of the rotary electric machine is not limited to this as illustrated below, and various publicly known not to be exemplified below. The structure of is also available.
In the above-described embodiment, the permanent magnet field type electric motor has been described as an example as the synchronous motor, but the present invention is not limited to this. For example, the rotary electric motor may be a reluctance type electric motor or an electromagnet field type electric motor (winding field type electric motor).
In the above-described embodiment, the synchronous motor has been described as an example of the AC motor, but the present invention is not limited to this. For example, the rotary electric machine may be an induction motor.
In the above-described embodiment, the AC electric motor has been described as an example of the electric motor, but the present invention is not limited to this. For example, the rotary electric machine may be a DC motor.
In the above-described embodiment, the electric motor has been described as an example of the rotary electric machine, but the present invention is not limited to this. For example, the rotary electric machine may be a generator.

In the above embodiment, the case where the laminated core according to the present invention is applied to the stator core is illustrated, but it can also be applied to the rotor core.

In addition, it is possible to replace the components in the embodiment with well-known components as appropriate without departing from the spirit of the present invention, and the above-described modifications may be appropriately combined.

Hereinafter, the present invention will be specifically described with reference to Examples, but the present invention is not limited to the following description.
[Manufacturing Example 1]
An adhesive (Y-1) having an SP value of 7.5 (cal / cm ³ ) ^1/2 was prepared by mixing 80 parts by mass of isobutyl methacrylate and 20 parts by mass of polymethyl methacrylate.

[Manufacturing Example 2]
100 parts by mass of bisphenol F type epoxy resin (Tg: 130 ° C.) obtained by polymerizing epichlorohydrin and bisphenol F and 25 parts by mass of phenol novolac resin as a curing agent are mixed to have an SP value of 7.9 (cal). / Cm ³ ) A ^1/2 adhesive (X-1) was prepared.

[Manufacturing Example 3]
A SP value of 8. is obtained by mixing 100 parts by mass of a bisphenol F type epoxy resin (Tg: 130 ° C.) obtained by polymerizing epichlorohydrin and bisphenol F and 25 parts by mass of hexamethylphosphoric acid triamide as an organic phosphorus compound. An adhesive (X-2) of 5 (cal / cm ³ ) ^1/2 was prepared.

[Manufacturing Example 4]
An adhesive (X-3) having an SP value of 10.2 (cal / cm ³ ) ^1/2 was prepared by mixing 60 parts by mass of methyl methacrylate and 40 parts by mass of cyclohexyl methacrylate.

[Manufacturing Example 5]
SP by mixing 100 parts by mass of bisphenol F type epoxy resin (Tg: 130 ° C.) obtained by polymerizing epichlorohydrin and bisphenol F, 3 parts by mass of phenol novolac resin as a curing agent, and 1 part by mass of EPDM as an elastomer. An adhesive (Y-2) having a value of 10.8 (cal / cm ³ ) ^1/2 was prepared.

[Example 1]
From a steel sheet having a thickness of 0.3 mm to a rectangular steel sheet (width 25 mm) having a composition for a non-directional electromagnetic steel sheet containing Si: 3.0% by mass, Al: 0.5% by mass, and Mn: 0.1% by mass. Two pieces (× length 100 mm) were cut out. A caulking (length 3.0 mm × width 2.0 mm × height 0.25 mm) is formed on one of the two steel plates to form a first test steel plate, and the other is a second steel plate without caulking. It was used as a test steel plate.
Punching oil (SP value: 7.) is applied to the entire surface of the first test steel sheet on the side where the caulking convex portion is formed and the surface of the second test steel sheet facing the first test steel sheet side. 7 (cal / cm ³ ) ^1/2 ) was applied so that the application amount was 50 mg / m ² .
An adhesive (Y-1) is applied to a portion of the first test steel sheet other than the caulking convex portion so that the thickness is 0.27 mm so that the oil levels of the second test steel sheet face each other. Stacked. They are heat-bonded under the conditions of a temperature of 150 ° C. and a pressure of 100 Pa, and the adhesive (Y-1) is cured in a state where the tip of the caulking convex portion of the first test steel sheet is in contact with the second test steel sheet. And obtained a test piece.

[Examples 2 to 5]
A test piece was obtained in the same manner as in Example 1 except that the adhesive (X-1) to the adhesive (X-3) and the adhesive (Y-2) were used instead of the adhesive (Y-1).

[Example 6]
A test piece was obtained in the same manner as in Example 1 except that the adhesive (X-1) was applied to the tip surface of the caulking convex portion of the first test steel plate so that the coating amount was 1 g / m ² . ..

[Examples 7 to 10]
A test piece was obtained in the same manner as in Example 6 except that the adhesive (X-1) to the adhesive (X-3) and the adhesive (Y-2) were used instead of the adhesive (Y-1).

[Adhesive strength]
The adhesive strength (peeling strength) of the test pieces of each example was measured according to JIS K6850: 1999. The tensile test environment was normal temperature (25 ° C.). The test speed was 3 mm / min. Adhesive strength was evaluated according to the following criteria.
⊚: 100 kgf / cm ² or more.
〇: 50 kgf / cm ² or more and less than 100 kgf / cm ² .
Δ: 10 kgf / cm ² or more and less than 50 kgf / cm ² .
X: Less than 10 kgf / cm ² .

Table 1 shows the measurement results of the adhesive strength of Examples 1 to 10.

[Example 11]
From a 0.3 mm thick steel sheet having a composition for non-oriented electrical steel sheets containing Si: 3.0% by mass, Al: 0.5% by mass, and Mn: 0.1% by mass, punching oil (SP value: By punching using 7.7 (cal / cm ³ ) ^1/2 ), the electromagnetic steel sheet 40 having the first caulking C1 and the second caulking C2 as shown in FIG. 4 and the electromagnetic steel sheet without caulking as shown in FIG. Steel sheet 40 was obtained.
As shown in FIG. 6, an adhesive (X-2) is applied to the surface of the electromagnetic steel sheet 40 having the first caulking C1 and the second caulking C2 on the convex side for caulking so that the coating amount is 1 g / m ^2. Then, the electromagnetic steel sheets 40 without caulking were stacked. They were heat-bonded under the conditions of a temperature of 150 ° C. and a pressure of 100 Pa, and the adhesive (X-2) was cured to obtain a test piece.

[Example 12]
The test was carried out in the same manner as in Example 12 except that the adhesive (X-2) was applied to the surface of the electromagnetic steel sheet 40 having the first caulking C1 and the second caulking C2 on the convex side for caulking as shown in FIG. I got a piece.

Table 2 shows the measurement results of the adhesive strength of Examples 11 and 12.

10 ... rotary electric machine, 20 ... stator, 21 ... stator core, 40 ... electromagnetic steel plate, 41, 50, 52, 54, 56, 58, 60 ... adhesive part, M1, M2 ... boundary part.

Claims (12)

With multiple electrical steel sheets laminated to each other,
It is a laminated core in which all sets of electromagnetic steel sheets adjacent to each other in the laminating direction are fixed to each other.
Includes a first set in which the electrical steel sheets are crimped and not bonded, and a second set in which the electrical steel sheets are bonded and not crimped.
The electrical steel sheets at the boundary between the first set and the second set are bonded to each other with an adhesive having an SP value of 7.8 to 10.7 (cal / cm ³ ) ^1/2 . Laminated core. The laminated core according to claim 1, wherein the adhesive portion made of the adhesive that adheres the electromagnetic steel plates to each other at the boundary portion is provided in a dot shape on the same circumference as the caulking of the boundary portion in a plan view. At the boundary portion, the tip of the crimping convex portion of the first set of electrical steel sheets is adhered to the surface of the second set of electromagnetic steel sheets on the caulking convex portion side with the adhesive. Item 2. The laminated core according to Item 1 or 2. Claimed that at least a part of the boundary portion other than the caulking of the first set of electrical steel sheets is adhered to the caulked surface of the second set of electrical steel sheets with the adhesive. The laminated core according to 1 or 2. The laminated core according to claim 4, wherein the thickness of the adhesive portion made of the adhesive at the boundary portion in the laminating direction is the same as the height of the caulking convex portion of the caulking. Claim that the absolute value of the difference between the SP value of the punching oil used for the punching process of the electromagnetic steel sheet and the SP value of the adhesive is 0.1 to 2.3 (cal / cm ³ ) ^1/2. The laminated core according to any one of 1 to 5. Any one of claims 1 to 6, wherein the second set of electrical steel sheets are bonded to each other with an adhesive having an SP value of 7.8 to 10.7 (cal / cm ³ ) ^1/2. The laminated core described in. The electrical steel sheet includes an annular core back portion and a plurality of teeth portions that protrude inward in the radial direction of the core back portion from the core back portion and are arranged at intervals in the circumferential direction of the core back portion. The laminated core according to any one of claims 1 to 7, wherein the laminated core comprises. A rotary electric machine including the laminated core according to any one of claims 1 to 8. The method for manufacturing a laminated core according to claim 1.
An adhesive having an SP value of 7.8 to 10.7 (cal / cm ³ ) ^1/2 is applied to either or both of the first set of electrical steel sheets and the second set of electrical steel sheets. A method for manufacturing a laminated core, which is applied, cured, and bonded to each other. The adhesive is applied to at least a part of the first set of electromagnetic steel sheets other than the caulking portion so as to be thicker than the height of the caulking convex portion of the caulking.
The adhesive is cured in a state where the tip of the convex portion for caulking is in contact with the second set of electromagnetic steel sheets, and the electromagnetic steel sheets are formed by an adhesive portion having the same thickness as the convex portion for caulking. The method for manufacturing a laminated core according to claim 10, wherein the laminated cores are bonded to each other. The electromagnetic steel sheet is manufactured by punching using punching oil.
The laminated core according to claim 10 or 11, wherein the absolute value of the difference between the SP value of the punching oil and the SP value of the adhesive is 0.1 to 2.3 (cal / cm ³ ) ^1/2 . Production method.

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