JP4264273B2 - Method for manufacturing stator core of motor - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for manufacturing a stator core of various motors for improving the iron loss of a stator core, and more particularly to a technique of alternately laminating with an adhesive coating when forming a stator of a motor.
[0002]
[Prior art]
Conventionally, for example, a stator of a three-phase synchronous motor is configured by stacking punched pieces of electromagnetic steel sheets in the axial direction of a rotating shaft. The laminated steel sheet has an insulating layer formed on the surface, and after assembly, it is caulked mechanically, the end of the core is welded, or in some cases, an adhesive layer is coated. The core sheet is integrated by heating and melting. As an example of such a motor, a “variable reluctance motor” disclosed in Patent Document 1 is known.
In a motor core core sheet fixing method, electromagnetic steel plates are generally laminated and caulked or welded. However, when processing such as caulking or welding is performed, deterioration of the magnetic properties of the core becomes a problem. Further, since the laminated core such as caulking or welding is partially fixed, it may cause vibration or noise.
[0003]
The surface of the electromagnetic steel sheet is provided with an insulating film for the purpose of reducing eddy current loss. In addition to the original insulating properties, this insulating film has various functions such as corrosion resistance and punchability, but it is possible to further add functions as an adhesive to these coating characteristics, Technologies have been proposed. In other words, the insulating coating applied to the electromagnetic steel sheet is heated at the same time as the pressurization, so that the laminated steel sheet is bonded by melting and fusing the coating, so-called adhesive coating (Patent Document 2, Patent) Document 3) has been devised. This adhesive coating can alleviate the problems caused by caulking and welding, and is a technology that has recently begun to penetrate.
[0004]
[Patent Document 1]
Japanese Patent Laid-Open No. 2-119561 [Patent Document 2]
Japanese Patent Publication No.49-33491 [Patent Document 3]
Japanese Patent Publication No. 55-9815 [0005]
[Problems to be solved by the invention]
In order to improve the efficiency of the motor, for example, increase the output torque of the three-phase synchronous motor and reduce the shape, the magnetic flux density increases and the iron loss increases. On the other hand, if the cooling fan is increased in order to suppress heat generation due to iron loss, the entire motor becomes larger.
The revised Energy Conservation Law was announced and the top runner method was applied, which required further reduction of iron loss in motors of electrical equipment. Among them, the adhesive coating does not cause a short circuit between the core sheets as seen in caulking or welding, and the eddy current loss is small. However, since the adhesive coating is deteriorated by the stress relief annealing, it is not used for the core subjected to the stress relief annealing, and the iron loss reduction effect by the stress relief annealing is not enjoyed.
The objective of this invention is providing the manufacturing method of the stator core of the motor which can enjoy the two iron loss reduction effects combined with adhesive coating and strain relief annealing.
[0006]
[Means for Solving the Problems]
Specific means of the present invention are as follows.
In a method for manufacturing a stator core of a motor in which a plurality of core sheets each having a tooth around which a coil is wound are laminated in the thickness direction, the core sheet is punched from a normal electromagnetic steel sheet and then subjected to strain relief annealing ( A) and every other core sheet (B) punched out from a magnetic steel sheet that is coated with adhesive coating on both sides and not subjected to strain relief annealing, and then heat-treated under pressure to integrate them together A method for manufacturing a stator core of a motor.
[0007]
DETAILED DESCRIPTION OF THE INVENTION
In order to enjoy the effects of core strain relief annealing in the stator, and avoidance of interlayer short circuit due to adhesive coating, avoidance of processing strain and caulking at the same time, a combination of application method to the core of electrical steel sheet with adhesive coating and annealing process I thought it was important. The embodiment will be described in detail below.
[0008]
The core manufacturing process in the present invention is shown in FIG. In this process, the electrical steel sheet with adhesive coating applied to both sides and the electrical steel sheet not applied at all were separated in the punching process and the annealing process. The steel sheet to which the adhesive coating was applied was punched in the same manner as in a general process. The steel sheet without the adhesive coating was punched and then subjected to strain relief annealing at 750 ° C. in an annealing furnace. These two types of core sheets were conveyed by a belt conveyor or the like, and mechanically stacked alternately and laminated to prepare a core shape. After the lamination, the core was heated to 200 ° C., and the core was bonded and integrated by baking by applying a compressive force of 1 MPa.
[0009]
According to the manufacturing method of the present invention, a stator was constructed in which half of the core was made of an annealed core sheet (A) and the other half was made of an unannealed core sheet (B). This configuration is shown in FIG. A winding was inserted into this to constitute a stator part. Annealed steel sheet shows low iron loss and contributes to reduction of iron loss of the entire core. On the other hand, the steel sheet with adhesive coating adheres to adjacent steel sheets and plays a role of fixing the core, and at the same time contributes to suppression of an increase in iron loss due to interlayer short circuit and processing strain.
Hereinafter, the present invention will be described based on examples.
[0010]
【Example】
[Example 1]
The stator of the motor used in the experiment to which the present invention was applied was obtained by stacking core sheets so that the thickness of the steel sheet was 50H350 with a thickness of 0.5 mm, the rotor diameter was 40 mm, the outer diameter was 150 mm, and the lamination thickness was 50 mm. In constructing this stator, (1) a core to which the present invention is applied and every other steel sheet with adhesive coating is stacked and fixed, (2) a core composed only of steel sheets with adhesive coating and not annealed, 3) Iron loss (W15 / 50; 1.5T iron at 50Hz) for 4 cases of core fixed by caulking after punching / strain relief annealing, and 4) core fixed by welding after punching / strain relief annealing Loss). Regarding iron loss measurement, two coils of several hundred turns are wound in the circumferential direction of the core, one coil is excited to measure this current, voltage is measured from the remaining coils, and a value is obtained using a wattmeter. It was. The result is shown in FIG.
[0011]
The core constituted by the present invention exhibited an annealing effect and had the lowest iron loss. A core made of only a steel sheet with an adhesive coating using a core sheet without annealing had a higher iron loss than that made of the present invention. In addition, the core fixed by caulking has a higher iron loss because a short circuit occurs between the core sheets. Fixing by welding is expected to have the highest iron loss even after strain relief annealing, and the interlayer short circuit is expected to be even greater.
[0012]
[Example 2]
Hereinafter, a second embodiment of the present invention will be described with reference to the drawings.
The core shape is 15HTH1000 with a steel plate thickness of 0.15 mm, the lamination thickness is 50 mm, the rotor diameter is 50 mm, and the outer diameter is 200 mm. As in Example 1, (1) a core to which the present invention is applied and every other steel sheet with adhesive coating is stacked and fixed, (2) a core composed of only adhesive coating and not annealed, (3) Iron loss (W15 / 50) in the same manner as in Example 1 for 4 cases of core fixed by caulking after punching / strain relief annealing, and 4 core fixed by welding after punching / strain relief annealing It was measured. The result is shown in FIG.
[0013]
The core constituted by the present invention exhibited an annealing effect and had the lowest iron loss. The core composed only of the adhesive coating using the core sheet without annealing had a higher iron loss than that composed in the present invention. Moreover, after punching and strain relief annealing, the core fixed by caulking or welding had higher iron loss.
[0014]
【The invention's effect】
As described above, according to the present invention, an adhesive coating is used for fixing the lamination, and the effect of simultaneously enjoying the fixing and annealing effects by the adhesive coating is expected by alternately laminating the annealed steel sheet and the steel sheet without annealing. Can do.
[Brief description of the drawings]
FIG. 1 is a view showing a manufacturing process of the present invention.
FIG. 2 is a diagram showing a configuration of a core according to the present invention.
FIG. 3 is a diagram illustrating an effect of the embodiment.
FIG. 4 is a diagram showing the effect of the embodiment.

Claims (1)

In a method for manufacturing a stator core of a motor in which a plurality of core sheets each having a tooth around which a coil is wound are laminated in the thickness direction, the core sheet is punched from a normal electromagnetic steel sheet and then subjected to strain relief annealing ( A) and every other core sheet (B) punched out from a magnetic steel sheet that is coated with adhesive coating on both sides and not subjected to strain relief annealing, and then heat-treated under pressure to integrate them together A method for manufacturing a stator core of a motor.

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