JPH10146028A - Manufacture of motor coil - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the heat radiative property of the coil by reducing pores remaining in the filler between the lead wires of a motor coil. SOLUTION: A lead wire 10 is soaked in a filler container 14 which has reserved fillers being thermosetting resin containing fillers so as to make the fillers deposit on the surface. The lead wire 10 to which these fillers deposit is wound on a given magnetic pole 30 by an automatic winder 16 so as to form a coil-shaped object. Then, the filler is hardened by heating to get a stator. Since the filler is adhering to the surface of a lead wire 10, the filler is supplied enough between the lead wires 10 even in case that the viscosity of the filler is high, so the remaining pores can be reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a coil formed by winding a conducting wire a plurality of times, and more particularly to a method for manufacturing a coil used for a motor.

[0002]

2. Description of the Related Art In order to efficiently dissipate heat generated in a coil of a motor, there is known a technique in which after a coil is formed, a resin is filled in a gap between conductors forming the coil. In this technique, a resin having fluidity is impregnated and then cured to fill the space between the conductive wires. According to this, the air in the gap between the conductors is reduced, and the heat resistance is reduced, so that the heat dissipation is improved. Further, there is known a technique in which a powder of a ceramic material such as alumina called a filler is added to the resin to further reduce the thermal resistance between conductive wires. By reducing the thermal resistance between the conductors, the heat generated in the conductors is quickly transferred to the motor core and the like, and the heat dissipation is improved.

[0003]

In recent years, there has been an increasing demand for downsizing and high output of motors. However, this has led to an increase in the amount of heat generated per unit volume, and higher heat radiation is required. It will be. As described above, when the resin is impregnated in the gap between the coil conductors, when the content of the filler is increased, the thermal conductivity of the filler in which the resin is cured improves, but on the other hand, the viscosity increases, Air does not sufficiently enter the gap between the conductors, leaving air. Therefore, there has been a problem that the thermal resistance is increased by the residual air, and the heat radiation of the entire coil is not improved or is not sufficiently improved.

The present invention has been made in order to solve the above-mentioned problems, and a motor coil capable of reducing residual air between coil conductors even when a filler having a high filler content and a high viscosity is used. It is an object of the present invention to provide a method for producing the same.

[0005]

In order to achieve the above-mentioned object, a method of manufacturing a motor coil according to the present invention is a method of manufacturing a motor coil formed by winding a conductive wire a plurality of times. A step of attaching a filler, which is a resin containing, a step of winding a conductive wire to which the filler is attached into a coil shape, and a step of curing the filler.

[0006] Since the conductive wire to which the filler, which is a resin containing a filler, is previously formed into a coil shape, the filler acts before filling by filling the gap between the conductive wires due to the fluidity of the filler. . Therefore, even when the viscosity of the filler is relatively high, it is possible to suppress the air from remaining between the conductive wires formed in a coil shape. Therefore,
It is possible to improve the thermal conductivity, which is reduced by the air remaining between the conductors, and to provide a motor coil having good heat dissipation.

[0007]

Embodiments of the present invention (hereinafter, referred to as embodiments) will be described below with reference to the drawings. 1 to 4 are process diagrams of the method for manufacturing a motor according to the present embodiment.

FIG. 1 shows a filler adhering step and a coil forming step of adhering a filler to the conductive wire 10 and winding the same to form a coil. The conductor 10 is an enamel-coated copper wire conventionally used as a coil conductor. The conducting wire 10 is wound around a reel 12 and is sequentially fed from here. The fed wire 10 is immersed in a filler tank 14 for storing a thermosetting resin such as an epoxy resin containing a filler. Then, the coil is formed around the stator core 18 of the motor by the automatic winding machine 16.

The filler stored in the filler tank 14 preferably contains an epoxy resin containing alumina or alumina nitride powder as a filler at a weight ratio of 75%. As the conductor 10 passes through the filler tank 14, the filler adheres to the surface of the conductor 10. With the filler adhered, the conductive wire 10 passes through the nozzle 20 of the automatic winding machine 16 and reaches the first hook 22 and the second hook 24. One end of the conducting wire 10 is a holder 2 that supports the stator core 18.
The coil is wound around a pin 28 protruding from the nozzle 6 and is sequentially pulled out from the nozzle 20 by the first and second hooks 22 and 24, and wound around the magnetic pole 30 to form a coil. In the process of forming this coil, the conductor 1
Since the filler adhering to the surface of No. 0 has fluidity, it flows between the wound conductive wires 10 so as to fill the gap. Thereby, the air between the conductive wires 10 is pushed out, and the air remaining when the coil is completed can be reduced.

FIG. 2 shows a filler dropping step of further penetrating the filler by dropping between the conductive wires 10 of the coil formed in the previous step. In the figure, the stator core 18 is shown.
Is shown a stator 34 in which the coil 32 is formed by winding the conducting wire 10. In this state, in order to further impregnate the filler between the conductors 10, the same filler as the filler adhered to the conductor 10 in the previous step is dropped from the dripping nozzle 36. The amount of the remaining air can be further reduced by dropping and entering the gap between the conductive wires 10.

FIG. 3 shows a deaeration step performed to further reduce the amount of residual air. After completion of the filler dropping process, the stator 34 is placed in a vacuum desiccator 38, and the vacuum desiccator 3 is driven by a vacuum pump (not shown).
The pressure in the chamber 8 is preferably reduced to 1.3 hPa (1 Torr). Thereby, the air remaining between the conductors 10 can be further reduced.

FIG. 4 shows a curing step for curing the filler in the coil 32. After the deaeration step, the stator 34 is placed in the heating furnace 40 and heated here. By this heating, the resin adhering to the conductive wire 10 in the filler adhering step and the filler impregnated in the coil in the filler dropping step are hardened. The resulting coil has less air, ie, no air bubbles, remaining between the conductors 10 of the coil, and has high thermal conductivity.

If sufficient heat radiation can be obtained even if one or both of the filler dropping step and the degassing step are omitted, it is possible to omit this step.

Further, the filler dropping step shown in FIG. 2 and the deaeration step shown in FIG. 3 can be replaced with a dipping step shown in FIG. In the immersion step, the stator 34 in which the coil is formed in the coil forming step of FIG. 1 is immersed in the core filler tank 42, and the core filler tank 42 is depressurized and degassed by the vacuum desiccator 44. is there.
The dipping process reduces air remaining between the conductors 10 of the coil, and reduces bubbles when the coil is completed by a subsequent curing process.

In the above-described embodiment, a case has been described in which one conductor 10 is sequentially wound to form a coil. However, after a plurality of conductors are bundled to form a conductor bundle, this conductor bundle is wound once. Alternatively, it is also possible to form a coil by winding a plurality of times. In this case, the filler is attached to one conductor before forming the conductor bundle. After that, when the wire bundle is formed, the wire bundle can be immersed in the filler tank, and when the coil is formed, the filler can be dropped as shown in FIG. .

With respect to the amount of the filler contained in the resin, an appropriate value is determined as follows. As the resin, a thermosetting epoxy resin was used, and alumina (Al ₂ O ₃ ) powder was used as a filler. The test was performed using four kinds of samples shown in FIG. 6 having different filler contents. The filler amount is four kinds of 60, 75, 80 and 90 weight percent, and their viscosities are 1 × 10 ⁵ , 3 × 10 ⁵ and 6 at room temperature.
× 10 ⁵ , 2 × 10 ⁶ cP.

The porosity of the filler was measured by the test method shown in FIG. 7 using the above-mentioned sample. (A) Thirty wires 100 used for a motor coil are arranged to have a length of 200 mm. (B) This is immersed in a sample tank 102 storing the above-mentioned sample, and a sample is attached to the wire 100. (C) A bundle of 30 conductors 100 to which a sample is attached is bound at three locations near both ends and at the center in a slightly twisted state to form a conductor bundle 104. The reason why the bundled conductors 100 are twisted is to minimize the gap between the conductors. (D) This is placed on a silicon tray 106, and a sample similar to the sample stored in the sample tank 102 is dropped from the dropping nozzle 108.
(E) The wire bundle 104 is placed in the vacuum desiccator 110 while being placed on the silicon bath 106, and the pressure in the desiccator 110 is reduced by a vacuum pump. (F) The wire bundle 104 is taken out of the vacuum desiccator 110, put into a heating furnace 112 together with the silicon bath, and heated to cure the filler.

The porosity, which is the ratio of the area of the pores to the cross-sectional area of the filler, is calculated in five cross sections of the wire bundle 104 after the filler has hardened, and this is shown in the graph of FIG. It is. When the conductors 100 were not individually immersed in the filler, and when the conductor bundle 104 was
In the case where the sample was not degassed by No. 10, a large amount of pores were contained. From FIG. 8, the viscosity is about 3-6 × 10 ⁵ c
P, if the filler amount is 75 to 80%, the number of pores is small,
Therefore, a motor coil having low thermal resistance can be manufactured.

[Brief description of the drawings]

FIG. 1 is a diagram showing a filler adhering step and a coil forming step of the present embodiment.

FIG. 2 is a view showing a filler dropping step of the present embodiment.

FIG. 3 is a view showing a deaeration step of the embodiment.

FIG. 4 is a view showing a curing step of the embodiment.

FIG. 5 is a view showing a dipping step of another embodiment.

FIG. 6 is a view showing characteristics of a sample of a filler.

FIG. 7 is an explanatory diagram of a characteristic test of a filler.

FIG. 8 is a diagram showing porosity versus viscosity of a filler obtained as a result of a property test.

[Explanation of symbols]

10 wire, 14 filler tank, 16 automatic winding machine, 18
Stator core, 30 magnetic poles, 32 coils, 34 stator, 36 drip nozzle, 38, 44 vacuum desiccator, 40 heating furnace, 42 core filler tank.

Claims (1)

[Claims] 1. A method for manufacturing a motor coil formed by winding a conductive wire a plurality of times, comprising: attaching a filler, which is a resin containing a filler, to the conductive wire; A method for manufacturing a motor coil, comprising: a step of forming the filler into a shape; and a step of curing the filler.