Method for producing laminate of amorphous metal or nanocrystalline metal plate members

Abstract

Provided is a method for producing a laminate (M) of an amorphous metal or nanocrystalline metal plate members (38), the method comprising: a lamination step for forming a laminate (M) by layering a plurality of plate members (38); and a welding step for irradiating the laminate (M) from one end to the other end in the layering direction of the laminate (M) with a welding beam to perform keyhole welding, wherein the lamination step includes a step for disposing prescribed metal members (39) on the plate members (38) located at both ends of the laminate (M), and the welding step includes a step for irradiating the metal members (39) with the welding beam.

Description

Method for manufacturing a laminate of plate members made of amorphous metal or nanocrystalline metal

[0001] The present disclosure relates to a method for manufacturing a laminate of plate members made of amorphous metal or nanocrystalline metal.

[0002] The core of the stator provided in the motor described in Patent Document 1 is composed of a laminate of metal plates made of amorphous metal or nanocrystalline metal. Compared with general electromagnetic steel sheets, in amorphous metal plates or nanocrystalline metal plates, eddy currents in the plate thickness plane are less likely to flow, and an increase in iron loss can be suppressed.

[0003] Japanese Patent No. 6656428

[0004] As one method of welding metal plates facing each other in the stacking direction, keyhole welding can be considered. In keyhole welding, for example, a welding laser is irradiated on a predetermined position on a metal plate located at one end of the laminate, and the metal is melted so that a hole penetrates in the stacking direction. Thereby, amorphous metal plates facing each other in the stacking direction are welded to each other.

[0005] However, the surface of an amorphous metal plate or a nanocrystalline metal plate is relatively rough and has innumerable minute irregularities. As a finding, it has been obtained that minute gaps are generated between the stacked amorphous metal plates or between the nanocrystalline metal plates due to such innumerable irregularities.

[0006] However, when performing keyhole welding on a laminate of plate members made of amorphous metal or nanocrystalline metal, as shown in FIG. 9, the melted metal sinks downward by filling the gaps between the plate members, and as a result, a dent occurs at the upper end of the welded portion (the hatched portion in FIG. 9). This dent reduces the bonding strength between the plate members at the upper part of the laminate, and there is a risk of poor welding at the upper part of the laminate.

[0007] An object of the present disclosure is to improve the bonding strength between plate members in a laminate of plate members made of amorphous metal or nanocrystalline metal.

[0008] The first aspect is a method for manufacturing a laminate (M) of amorphous metal or nanocrystalline metal plate members (38), comprising: a lamination step of constructing the laminate (M) by laminating a plurality of the plate members (38); and a welding step of performing keyhole welding by irradiating the laminate (M) from one end to the other in the lamination direction with a welding laser or welding beam, wherein the lamination step includes a step of arranging predetermined metal members (39) on the plate members (38) located at both ends of the laminate (M), and the welding step includes a step of irradiating the metal members (39) with the welding beam.

[0009] In the first embodiment, a weld is formed by molten metal using a welding laser that penetrates the laminate (M). This weld connects opposing plate members (38) in the lamination direction. Even if a dent occurs at the upper end of the weld due to a gap between the opposing plate members (38), the molten metal member (39) fills the hole in the upper part of the laminate (M), thus suppressing poor joining of the upper plate members (38) of the laminate (M). In this way, the molten volume of the metal member (39) acts as a weld allowance, suppressing a decrease in the joint strength due to welding of the upper plate members (38) of the laminate (M), and improving the joint strength between the plate members (38) of the laminate.

[0010] In addition, when the laminate (M) is viewed from the stacking direction, the area melted by the welding beam is formed in a circular shape. If the side of the laminate (M) is welded, some of the molten metal will come into contact with the non-molten metal, while areas that do not come into contact with anything will remain (see Figure 8). If there is little molten metal, the molten metal tends to aggregate in such areas due to surface tension, which can cause welding defects. However, in keyhole welding, the non-molten metal surrounds the molten metal, so areas where the molten metal does not come into contact with anything are almost nonexistent. Therefore, in addition to suppressing the aggregation of molten metal, the length of the joint interface can be sufficiently secured because the molten metal is generally in contact with the non-molten metal, resulting in good welding and improved joint strength.

[0011] In addition, the molten metal attempts to fill the inner surface of the holes formed by the irradiation of the welding beam due to surface tension. As a result, each plate member (38) can come into close contact with the molten metal, improving the joint strength of the welds between the plate members (38).

[0012] In the second embodiment, the metal member (39) is an electromagnetic steel sheet (39) provided so as to cover the plate member (38).

[0013] In the second embodiment, the electrical steel sheet (39) covers both ends of the laminate (M) in the lamination direction. Since the electrical steel sheet (39) is thicker than the amorphous metal or nanocrystalline metal plate member (38), even if a depression occurs in the keyhole welding area of ​​the electrical steel sheet (39), it is possible to prevent the depression from reaching the plate member (38). Also, since the electrical steel sheet covers the entire plate member (38), the position of the keyhole welding area can be determined relatively freely.

[0014] A third embodiment is a laminate in which a plurality of amorphous metal or nanocrystalline metal plate members (38) are stacked, the laminate having a metal member (39) positioned on the plate members (38) located at the ends in the stacking direction, and adjacent plate members (38) in the stacking direction are fixed to each other by keyhole welding to the metal member (39).

[0015] In the third embodiment, the same effects as in the first embodiment can be obtained.

[0016] A fourth embodiment is the third embodiment, wherein the metal member (39) is an electromagnetic steel sheet (39) provided so as to cover the plate member (38).

[0017] In the fourth embodiment, the same effects as in the second embodiment can be obtained.

[0018] The fifth embodiment is a stator core composed of a laminate (M) of the third or fourth embodiment.

[0019] In the fifth embodiment, a stator core can be provided having a laminate in which the strength of the joints between plate members (38) facing each other in the lamination direction is improved.

[0020] The sixth embodiment is a stator core in which a plurality of the laminates of the third or fourth embodiment are stacked in the stacking direction.

[0021] In the sixth embodiment, a stator core can be manufactured by stacking multiple laminates (M). Stator cores of different sizes can be manufactured depending on the number of laminates (M).

[0022] The seventh embodiment is a motor having a stator core according to the fifth or sixth embodiment.

[0023] In the seventh embodiment, motor failures caused by damage to the laminate (M) can be suppressed by improving the bonding strength of the plate members (38) of the laminate (M).

[0024] The eighth aspect is a compressor having the motor of the seventh aspect.

[0025] In the eighth embodiment, the strength of the joint between opposing plate members (38) of the laminate is improved, which can suppress motor failures caused by damage to the laminate due to welding defects, and consequently, compressor failures.

[0026] The ninth embodiment is a blower equipped with the motor of the seventh embodiment.

[0027] In a ninth aspect, a blower having the motor of the present disclosure can be provided.

[0028] The tenth embodiment is a refrigeration system equipped with the compressor of the eighth embodiment.

[0029] In a tenth aspect, a refrigeration system comprising the compressor of the present disclosure can be provided.

[0030] Figure 1 is a schematic diagram of the refrigeration apparatus according to the embodiment. Figure 2 is a longitudinal cross-sectional view corresponding to a cross-section parallel to the axial direction in the compressor according to the embodiment. Figure 3 is a transverse cross-sectional view corresponding to a cross-section perpendicular to the axial direction in the motor. Figure 4 is a top view of the plate member according to the embodiment. Figure 5 is a cross-sectional view along the lamination direction of the laminate in each step of the manufacturing method of the laminate according to the embodiment. (a) shows the laminate after the lamination process. (b) shows the laminate after the welding process. Figure 6 is a stereoscopic perspective view showing the configuration of a modified laminate. Figure 7 is a cross-sectional view of a laminate corresponding to Figure 6(b) of another embodiment. Figure 8 is a diagram illustrating the shape of the weld formed when the side surface of the laminate is welded. Figure 9 is a cross-sectional view along the lamination direction of the laminate when a laminate without metal members is keyhole welded.

[0031] Embodiments of the present invention will be described below with reference to the drawings. The following embodiments are essentially preferred examples and are not intended to limit the scope of the present invention, its applications, or its uses. Furthermore, the embodiments, modifications, and other examples described below can be combined or partially replaced to the extent that the present invention is implementable. The terms "upper" and "lower" below indicate the directions shown in the figures. Also, in the cross-sectional view of the laminate shown in the figure, hatching of the plate members and electrical steel sheets has been omitted.

[0032] (1) Refrigeration device The refrigeration device (1) shown in Figure 1 has a refrigerant circuit (1a) filled with refrigerant. The refrigerant circuit (1a) is equipped with a compressor (10), a heat sink (2), an expansion valve (3), and an evaporator (4). The refrigerant circuit (1a) performs a vapor compression type refrigeration cycle.

[0033] In the refrigeration cycle, the refrigerant compressed by the compressor (10) releases heat into the air in the heat exchanger (2). The refrigerant that has released heat is depressurized by the expansion valve (3) and evaporates in the evaporator (4). The evaporated refrigerant is drawn back into the compressor (10).

[0034] The refrigeration system (1) may also be an air conditioning system, a water heater, a chiller unit, a cooling system for cooling the air inside the storage unit, etc.

[0035] (2) Compressor The compressor (10) shown in Figure 2 has a casing (11), a motor (30), a drive shaft (20), and a compression mechanism (22).

[0036] (2-1) Casing The casing (11) houses the motor (30), the drive shaft (20), and the compression mechanism (22). The casing (11) is a fully sealed container. The inside of the casing (11) is filled with high-pressure coolant discharged from the compression mechanism (22).

[0037] The casing (11) is made of a metal material. The casing (11) has a body (12), a bottom (13), and a top (14). The body (12) is a cylindrical metal member. Openings are formed at both axial ends of the body (12). The bottom (13) closes the lower opening of the body (12). The top (14) closes the upper opening of the body (12).

[0038] (2-2) Motor As shown in Figures 2 and 3, the motor (30) is positioned above the compression mechanism (22). The motor (30) has an inverter that controls its operating frequency. In other words, the compressor (10) is an inverter type with a variable operating frequency.

[0039] The motor (30) has a stator (31) and a rotor (40). The stator (31) is supported by the body (12) of the casing (11).

[0040] The stator (31) has a stator core (32) and a coil (33) wound around the stator core (32). The stator core (32) has an annular back yoke (34) and a plurality (nine in this example) of teeth (35) extending radially inward from the inner circumferential surface of the back yoke (34). A plurality (nine in this example) of core cuts (36) are formed on the outer circumferential surface of the back yoke (34). The core cuts (36) are grooves extending axially from the stator core (32).

[0041] The stator core (32) has a laminate (M). The laminate (M) is formed by laminating amorphous metal plate members (38) in the thickness direction thereof. The plate member (38) is a thin plate-like component shaped to have a back yoke (34) and teeth (35). In other words, the plate member (38) of the present disclosure constitutes the laminate (M) of the stator core (32). The thickness of the plate member (38) is formed to be 20 μm or more and 100 μm or less per sheet, preferably 20 μm or more and 50 μm or less, more preferably 20 μm or more and 30 μm or less. Details of the plate member (38) will be described later.

[0042] The rotor (40) is disposed inside the stator core (32). A drive shaft (20) is fixed to the axis of the rotor (40). A plurality of slots (41) are formed in the rotor (40). Permanent magnets are embedded inside the slots (41).

[0043] (2-3) Drive shaft The drive shaft (20) extends vertically along the axis of the casing (11). The drive shaft (20) is rotationally driven by a motor (30). The drive shaft (20) is rotatably supported by a bearing (29).

[0044] (2-4) Compression mechanism The compression mechanism (22) has a cylinder (23) and a piston (24) provided inside the cylinder (23). A cylinder chamber (25) is formed between the inner peripheral surface of the cylinder (23) and the outer peripheral surface of the piston (24). In the cylinder chamber (25), a fluid is compressed by the piston (24) driven by the drive shaft (20).

[0045] (2-5) Suction pipe and discharge pipe The compressor (10) has a suction pipe (2) and a discharge pipe (27). The suction pipe (26) radially penetrates the body (12) and communicates with the cylinder chamber (25). The low-pressure refrigerant in the refrigerant circuit (1a) is sucked into the cylinder chamber (25) through the suction pipe (26). The discharge pipe (27) axially penetrates the top (14) and communicates with the internal space of the casing (11). The refrigerant compressed by the compression mechanism (22) flows through the core cut (36) of the motor (30) and the like, and then is sent from the discharge pipe (27) to the refrigerant circuit (1a).

[0046] (3) Issues related to the manufacture of the laminate Hereinafter, the plate member (38) will be described as an amorphous metal plate. The amorphous metal plate used for the stator core of the present disclosure is a plate material made of an alloy mainly containing iron with a thickness of 50 μm or less. The amorphous metal plate is manufactured by rapidly cooling a molten metal formed into a thin plate shape. For example, by supplying the molten metal to the outer peripheral surface of a cylindrical body roll member, the molten metal touching the surface of the roll member is rapidly cooled, and a thin plate-shaped amorphous metal plate is formed on the surface of the roll member. By continuously supplying the molten metal to the roll member while rotating the roll member, the amorphous metal plate is extruded from the roll member in a foil strip shape. A plate member formed into a product shape can be obtained by punching the thus extruded foil strip-shaped amorphous metal plate using a punch and a die.

[0047] Since the amorphous metal plate is very thin and does not undergo plastic deformation, fixing by caulking is not practical, and it is desirable to fix it by some other method. For example, as a method of welding amorphous metal plates facing each other in the stacking direction, keyhole welding in which overlapping amorphous metal plates are welded by irradiating a welding laser or beam in the stacking direction of the laminate can be considered.

[0048] As shown in FIG. 9, in keyhole welding, when a welding laser is irradiated to the amorphous metal plate located at one end in the stacking direction of the laminate, the welding laser penetrates the laminate in the stacking direction, and each amorphous metal plate touched by the welding laser melts. As a result, when the laminate is viewed from the upper surface in the stacking direction, a cylindrical hole is formed in the amorphous metal plate, and the molten metal fills this hole to form a welded portion. The facing amorphous metal plate members are welded by this welded portion.

[0049] Here, the surface of the foil strip-shaped amorphous metal plate has relatively coarse and minute irregularities. In particular, there is a finding that the surface of the amorphous metal plate tends to become rough by the method of rapidly cooling the molten metal on the outer peripheral surface of the rotating metal roll member as described above. Therefore, minute gaps are formed between adjacent metal plates in the stacking direction in the laminate of the amorphous metal plates.

[0050] Therefore, when a welding laser is irradiated onto the upper end of a laminate of amorphous metal plates, the molten metal sinks downward due to the gaps. As a result, the upper end of the weld becomes concave. This concaveness may lead to insufficient welding of the amorphous metal plates at the top of the laminate. In other words, the joint between multiple amorphous metal plates located at the top of a laminate welded by keyhole welding may not be sufficient, and the strength of the joint between the amorphous metal plates cannot be adequately ensured.

[0051] In addition, the irradiation length of the welding laser needs to be adjusted according to the thickness of the laminate (the distance from one end to the other in the lamination direction). If the irradiation length of the welding laser is longer than the thickness of the laminate, the welding laser will penetrate the bottom end of the laminate. On the other hand, if the irradiation length of the welding laser is shorter than the thickness of the laminate, the welding laser will not reach the bottom end of the laminate, and the amorphous metal plate cannot be welded at the bottom of the laminate. Therefore, it is necessary to adjust the irradiation length of the welding laser to reach the amorphous metal plate located at the bottom end of the laminate, but since the amorphous metal plate is very thin, it is relatively difficult to precisely adjust the irradiation length. Such problems can also occur when the plate material is a metal plate made of nanocrystalline metal.

[0052] In view of these challenges, in the laminate (M) of this embodiment, electromagnetic steel sheets (39) are formed on the surfaces of the plate members (38) located at both ends in the lamination direction of the laminate (M). The manufacturing method of the laminate (M) of this embodiment will be described below.

[0053] (4) Method for manufacturing a laminate The method for manufacturing a laminate according to this embodiment comprises a lamination step of constructing a laminate (M) by stacking a plurality of plate members (38), and a welding step of performing keyhole welding by irradiating a welding laser from one end to the other in the lamination direction of the laminate (M).

[0054] The plate member (38) is a generally annular thin plate member in which the back yoke (34) and teeth (35) are integrally molded. The plate member (38) is an amorphous metal plate. Specifically, the plate member (38) is a metal plate of an amorphous soft magnetic material. The plate member (38) may also be a nanocrystalline metal plate containing a nanocrystalline soft magnetic material. The amorphous soft magnetic material or nanocrystalline soft magnetic material is composed of, for example, at least one magnetic metal selected from the group consisting of iron, cobalt, and nickel, and at least one nonmagnetic metal. The at least one nonmagnetic metal is selected from the group consisting of, for example, boron, carbon, phosphorus, aluminum, silicon, titanium, vanadium, chromium, manganese, copper, yttrium, zirconium, niobium, molybdenum, hafnium, tantalum, and tungsten. The amorphous soft magnetic material or nanocrystalline soft magnetic material is not limited to the above examples.

[0055] As shown in Figure 5(a), the lamination process includes stacking a plurality of plate members (38) and then placing electrical steel sheets (39), which are metal members, on the plate members (38) located at both ends in the lamination direction. In other words, the laminated body (M) of plate members (38) is sandwiched between two electrical steel sheets (39) from both sides in the lamination direction.

[0056] The shape of the electromagnetic steel sheet (39) is the same as that of the plate member (38). The thickness of the electromagnetic steel sheet (39) is 200 μm to 500 μm. In other words, the electromagnetic steel sheet (39) is about 5 to 25 times thicker than the amorphous metal plate member (38). The surface area of ​​the electromagnetic steel sheet (39) is the same as or greater than that of the plate member (38). The electromagnetic steel sheet (39) is installed so as to cover the plate member (38).

[0057] As shown in Figure 5(b), the welding process includes irradiating one of the electrical steel sheets (39) with a welding laser. The welding laser melts the metal from the upper electrical steel sheet (39) to the lower electrical steel sheet (39) of the laminate (M). The irradiation distance of the welding laser is adjusted to the length that reaches from one electrical steel sheet (39) to the other electrical steel sheet (39). As a result, a cylindrical hole H is formed in the irradiated portion of the laminate (M), and a welded portion Q is formed that fills the hole H formed by the molten metal.

[0058] The welding laser is irradiated onto a predetermined position on the electrical steel sheet (39). Preferably, the welding laser is irradiated onto a position on the electrical steel sheet (39) that does not interfere with the magnetic flux generated in the stator core (32) by the operation of the motor (30). For example, as shown in Figure 4, it is preferable to irradiate the back yoke (34) to a position on the radially outward side of the teeth (35) (irradiated position P).

[0059] Furthermore, the welding laser is irradiated to multiple locations on the electromagnetic steel sheet (39). The laser is irradiated at positions that divide 360° equally around the center point of the back yoke (34). For example, if there are two irradiation positions, the welding laser is irradiated at positions 0° and 180° around the center point of the back yoke (34). If there are three irradiation positions, the welding laser is irradiated at positions 0°, 120° and 240° around the center point of the back yoke (34). In this embodiment, the welding laser is irradiated to three irradiation positions P (see Figure 4).

[0060] In the laminate (M) obtained by the above manufacturing method, even if a depression occurs at the irradiated position P in the electromagnetic steel sheet (39) located at the upper end, the depression does not reach the plate member (38) directly below the electromagnetic steel sheet (39). In addition, since the welding laser reaches partway through the thickness direction of the electromagnetic steel sheet (39) located at the lower end of the laminate (M), it penetrates the plate member (38) directly above the electromagnetic steel sheet (39) but does not penetrate the electromagnetic steel sheet (39). As a result, all the plate members (38) sandwiched between the two electromagnetic steel sheets (39) are joined to each other by welding.

[0061] (7) Features (7-1) Feature 1 The manufacturing method of the plate member (38) of this embodiment comprises a lamination step of constructing a laminate (M) by laminating a plurality of plate members (38), and a welding step of performing keyhole welding by irradiating the laminate (M) from one end to the other in the lamination direction with a welding laser or welding beam. The lamination step includes a step of arranging predetermined metal members (39) on the plate members (38) located at both ends of the laminate (M). The welding step includes a step of irradiating the metal members (39) with a welding laser or welding beam.

[0062] As shown in Figure 4, when the laminate (M) is viewed from the stacking direction, the molten portion at the welding beam irradiation position P is formed in a circular shape. If the side surface of the laminate (M) is welded, the molten metal will partially contact the non-molten metal, but areas where it does not contact anything will remain (see Figure 9). In such areas, the molten metal will aggregate due to surface tension, causing welding defects. However, in keyhole welding, the non-molten metal surrounds the molten metal, so areas where the molten metal does not contact anything are almost nonexistent. Therefore, in addition to suppressing the aggregation of the molten metal, the length of the joint interface can be sufficiently secured because the molten metal is generally in contact with the non-molten metal, resulting in good welding and improved joint strength.

[0063] Furthermore, the molten metal attempts to fill the cylindrical holes H formed by the irradiation of the welding laser due to surface tension. As a result, each plate member (38) is welded in close contact with the molten metal, thereby improving the joint strength of the weld between the plate members (38).

[0064] Furthermore, a welded joint is formed that fills the cylindrical hole created by the welding laser penetrating the laminate (M). This welded joint welds together the plate members (38) that face each other in the lamination direction. Even if a dent occurs at the upper end of the welded joint due to a gap between the facing plate members (38), the molten metal member (39) fills the hole in the upper part of the laminate (M), thus suppressing welding defects in the upper plate members (38) of the laminate (M). In this way, the molten volume of the metal member (39) becomes the weld allowance, filling the hole in the upper part of the laminate (M). As a result, a decrease in the strength of the weld in the upper part of the laminate (M) can be suppressed. Consequently, the strength of the joint between the facing plate members (38) of the laminate (M) can be improved.

[0065] (7-2) Feature 2 The metal member (39) in this embodiment is an electromagnetic steel sheet (39) provided so as to cover the plate member (38). The electromagnetic steel sheet (39) is thicker than the plate member (38), having a thickness of 5 to 25 times that of the plate member (38). Therefore, even if a depression is formed on the upper part of the laminate (M) by irradiation with a welding laser, the molten electromagnetic steel sheet (39) becomes the welding allowance and fills the hole portion on the upper part of the laminate (M). This suppresses the reduction in joint strength due to welding of the plate member (38) on the upper part of the laminate (M). In addition, since the electromagnetic steel sheet covers the entire plate surface of the plate member (38) located at the edge of the laminate (M), the position of the keyhole welding area can be determined relatively freely.

[0066] (7-3) Feature 3 In this embodiment, a metal member (39) is placed on the plate member (38) located at the end in the stacking direction of the laminate (M), and by irradiating the metal member (39) with a welding beam, adjacent plate members (38) in the stacking direction are welded together. As described in Feature (1) above, a laminate (M) can be provided in which the strength of the joint of the plate member (38) at the top of the laminate (M) is improved.

[0067] (7-4) Feature 4 The metal member (39) in this embodiment is an electromagnetic steel sheet (39) provided so as to cover the plate member (38). Since the thickness of the electromagnetic steel sheet (39) is sufficiently greater than that of the plate member (38), even when keyhole welding is performed, a laminate (M) can be provided in which the joint strength of the upper plate member (38) of the laminate (M) is relatively strong. In addition, the degree of freedom of the processing conditions for keyhole welding is increased, and it is easier to determine the welding conditions.

[0068] (7-5) Feature 5 The stator core (32) of this embodiment is composed of a laminate (M) manufactured by the manufacturing method of this embodiment. In this way, even though it is a laminate of amorphous plate members (38) welded by keyhole welding, the bonding strength between the plate members (38) is relatively strong, so a stator core with high quality can be provided.

[0069] (7-6) Feature 6 The motor (30) has the stator core (32) of this embodiment. The stator core (32) has a laminate (M) in which the strength of the joints between the plate members (38) is sufficient, so that failure of the motor (30) caused by poor joints between the plate members (38) can be suppressed.

[0070] (7-7) Feature 7 The compressor (10) has the motor (30) of this embodiment. As described in Feature 6 above, failure of the motor (30) due to poor joining of the plate members (38) is suppressed, and consequently, failure of the compressor (10) can also be suppressed.

[0071] (8) Modified Example The modified stator core (32) shown in Figure 6 is configured such that multiple laminates (M) of the above embodiment are stacked in the stacking direction. Specifically, the stator core (32) of this modified example has two laminates (M) that are adjacent to each other in the vertical direction. The two laminates (M) are a first laminate (M) and a second laminate (M). The first laminate (M) is located above the second laminate (M). The electromagnetic steel sheet (39) located at the lower end of the first laminate (M) and the electromagnetic steel sheet (39) located at the upper end of the second laminate (M) are fixed to each other by welding. Specifically, the electromagnetic steel sheets (39) located at the lower end of the first laminate (M) and the electromagnetic steel sheet (39) located at the upper end of the second laminate (M) are welded to each other by melting a part of the side surface of each electromagnetic steel sheet (39) while they are in contact with each other. This results in a stator core (32) having a first laminate (M) and a second laminate (M).

[0072] In this way, by simply preparing multiple laminates (M), stator cores (32) of different sizes can be manufactured, allowing for the rapid and easy production of stator cores (32) of desired sizes. Furthermore, when manufacturing relatively large stator cores (32), the welding laser may not reach from one end to the other in the lamination direction. However, in this modified example, the stator core (32) only requires welding together the electromagnetic steel sheets (39) of two laminates (M) facing each other in the vertical direction, thus enabling the production of large stator cores (32) regardless of the irradiation length of the welding laser.

[0073] (9) Other embodiments The laminates and methods for manufacturing the laminates of the above embodiments and modified examples may be configured as follows.

[0074] The metal member (39) in the above embodiment does not have to be an electrical steel sheet. The metal member (39) may be, for example, a plate member (38). In this case, the method for manufacturing the laminate includes the step of removing the plate member (38) at the top of the laminate (M) where a recess has been created by keyhole welding and the strength of the welded joint is relatively weak (the plate member (38) located at the top end of Figure 7), and the plate member (38) at the bottom of the laminate (M) where the welding laser could not reach (the plate member (38) located at the bottom end of Figure 7). In this way, by removing the plate member (38) with insufficient keyhole welding, a laminate (M) consisting only of amorphous metal or nanocrystalline metal with sufficient bonding strength can be obtained.

[0075] In the above embodiment and the above modified example, the electrical steel sheet, which is the metal member (39), may be provided in part between adjacent plate members (38) in the lamination direction of the laminate (M).

[0076] In the above embodiment, the metal member (39) may be placed only on the plate member (38) located at the upper or lower end of the laminate (M).

[0077] The metal member (39) in the above embodiment only needs to be positioned among the plate members (38) arranged at one end and the other end of the laminate (M) at the position where the welding laser is irradiated, and does not need to be provided to cover the entire surface.

[0078] Any laser capable of keyhole welding is acceptable for welding. Alternatively, a heating means capable of keyhole welding may be used instead of a welding laser. For example, if a welding beam is used, an electron beam may also be used.

[0079] There are no particular limitations on the thickness (length in the lamination direction) of the laminate (M). The thickness of the laminate (M) should be such that the welding beam can reach the metal member (39) at the bottom of the laminate (M).

[0080] The stator core (32) in the above modified example may have three or more laminates (M).

[0081] The motor (30) in the above embodiments and modifications may also be applied to a blower (not shown). The blower includes, for example, a motor (30) and a fan that rotates when driven by the motor (30).

[0082] Typical amorphous or nanocrystalline soft magnetic materials include, for example, iron-cobalt alloys, iron-nickel alloys, iron-aluminum alloys, iron-silicon alloys, iron-tantalum alloys, or iron-zirconium alloys. Examples of iron-cobalt alloys include Fe・Co alloys and Fe・Co・V alloys. Examples of iron-nickel alloys include Fe・Ni alloys, Fe・Ni・Mo alloys, Fe・Ni・Cr alloys, and Fe・Ni・Si alloys. Examples of iron-aluminum or iron-silicon alloys include Fe・Al alloys, Fe・Al・Si alloys, Fe・Al・Si・Cr alloys, Fe・Al・Si・Ti・Ru alloys, and Fe・Al・O alloys. Examples of iron-tantalum alloys include Fe・Ta alloys, Fe・Ta・C alloys, and Fe・Ta・N alloys. Iron-zirconium alloys include, for example, Fe-Zr-N alloys.

[0083] Typical amorphous soft magnetic materials or nanocrystalline soft magnetic materials may include, for example, cobalt alloys containing cobalt and at least one element from the group consisting of zirconium, hafnium, niobium, tantalum, titanium, and yttrium. The cobalt alloy preferably contains 80 at% or more cobalt. Cobalt alloys containing 80 at% or more cobalt tend to become amorphous when formed into films. Furthermore, cobalt alloys containing 80 at% or more cobalt have excellent magnetic properties due to their low crystalline magnetic anisotropy, low crystalline defects, and low grain boundaries. Suitable amorphous soft magnetic materials include, for example, Co·Zr alloys, Co·Zr·Nb alloys, and Co·Zr·Ta alloys.

[0084] Amorphous soft magnetic materials have an amorphous structure as their main structure. When observing the X-ray diffraction pattern of amorphous soft magnetic materials, they do not have clear peaks in the X-ray diffraction pattern. When observing the X-ray diffraction pattern of amorphous soft magnetic materials, they have a broad halo pattern.

[0085] Nanocrystalline soft magnetic materials are formed by applying heat treatment to amorphous soft magnetic materials that have an amorphous structure. Nanocrystalline soft magnetic materials are soft magnetic materials in which nanocrystals are deposited by heat treatment of amorphous soft magnetic materials. Nanocrystalline soft magnetic materials have a nanocrystalline structure. Nanocrystals are polycrystalline materials with particle sizes ranging from several nanometers to tens of nanometers.

[0086] When observing the X-ray diffraction pattern of nanocrystalline soft magnetic materials, X-ray diffraction peaks are found at positions corresponding to the lattice spacing of the crystal planes. The crystallite size can be calculated from the width of the X-ray diffraction peaks using Scherrer's equation. A nanocrystal is defined as a material whose crystallite size, calculated from the full width at half maximum of the diffraction peaks using Scherrer's equation, is less than 1 micrometer. In this disclosure, the crystallite size of the nanocrystal (the crystallite size calculated from the full width at half maximum of the diffraction peaks using Scherrer's equation) is preferably 100 nanometers or less, and more preferably 50 nanometers or less. Furthermore, the crystallite size of the nanocrystal is preferably 5 nanometers or more.

[0087] Nanocrystalline soft magnetic materials can improve magnetic properties because the crystallite size of the nanocrystals is 100 nanometers or less, as described above. In contrast, the crystallite size of conventional electrical steel sheets is on the order of micrometers, and is generally 50 micrometers or larger.

[0088] While embodiments and modifications have been described above, it will be understood that a variety of changes in form and details are possible without departing from the spirit and scope of the claims. Furthermore, these embodiments and modifications may be combined or substituted as appropriate, as long as they do not impair the functions of the subject matter of this disclosure. The terms “first,” “second,” etc., described above are used to distinguish the phrases to which these terms are attached and do not limit the number or order of such phrases.

[0089] As described above, this disclosure is useful for a method of manufacturing a laminate of amorphous metal or nanocrystalline metal plate members.

[0090] 10 Compressor 30 Motor 32 Stator core 38 Plate member 39 Electromagnetic steel sheet (metal member) M Laminate

Claims

1. A method for manufacturing a laminate (M) of amorphous metal or nanocrystalline metal plate members (38), comprising: a lamination step of constructing the laminate (M) by laminating a plurality of the plate members (38); and a welding step of performing keyhole welding by irradiating the laminate (M) from one end to the other in the lamination direction with a welding laser or welding beam, wherein the lamination step includes a step of arranging predetermined metal members (39) on the plate members (38) located at both ends of the laminate (M), and the welding step includes a step of irradiating the metal members (39) with the welding laser or welding beam.

2. The manufacturing method according to claim 1, wherein the metal member (39) is an electromagnetic steel sheet provided so as to cover the plate member (38).

3. A laminate comprising a plurality of amorphous metal or nanocrystalline metal plate members (38) stacked together, wherein a metal member (39) is positioned on the plate members (38) located at the ends in the stacking direction, and adjacent plate members (38) in the stacking direction are fixed to each other by keyhole welding to the metal member (39).

4. The laminate according to claim 3, wherein the metal member is an electromagnetic steel sheet provided so as to cover the plate member (38).

5. A stator core comprising the laminate according to claim 3 or 4.

6. A stator core configured such that a plurality of the laminates described in claim 3 or 4 are stacked in the stacking direction.

7. A motor comprising the stator core according to claim 5 or 6.

8. A compressor comprising the motor described in claim 7.

9. A blower comprising the motor described in claim 7.

10. A refrigeration apparatus comprising the compressor described in claim 8.

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