JPH056417B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a small electric motor applicable to a capacitor motor, a stepping motor, etc., and particularly to a coil bobbin with an intermediate core for a small electric motor with a sealed coil.

(Prior art) For example, small electric motors used in washing machines, etc.
Since moisture resistance is required, it is necessary to have good airtightness. Therefore, various techniques have been proposed for sealing the coils in small electric motors.

Fig. 5 shows one of them, in which coil sets 2 each consisting of a core 1, a coil bobbin 3, and a coil 4 are formed for one phase, and each coil set 2 is hermetically sealed by insert molding of resin 8. A small electric motor is formed by overlapping two coil sets 2 for two phases.

In addition, as shown in FIG. 6, the core 11
Two core groups consisting of core 12, core 13 and core 14 are stacked in two layers, coil bobbins 15 and 16 are insert-molded inside each core group, and coils 17 and 18 are wound around each coil bobbin 15 and 16. In some cases, a resin layer 19 is formed on the outside of each coil 17, 18 by insert molding to seal each coil 17, 18.

(Problems to be solved by the invention) According to the conventional example shown in FIG.
Since each coil bobbin is individually molded, wound and sealed, productivity is low and there are problems in that twice as many assembly steps are required as in the case of one coil.

Furthermore, according to the conventional example shown in FIG.
Many connection wires between the sealing resin layer 19 and each core or coil bobbin protrude from the outer periphery of the surface, resulting in poor sealing.Furthermore, it is necessary to insert mold each core 11, 12, 13, and 14 at the same time, and the winding Due to the nature of wiring, the core 14 cannot be used also as a motor case.

The present invention was made to solve these conventional problems, and by making it possible to mold two-phase coil bobbins at once, productivity can be improved, and the product has excellent sealing performance. An object of the present invention is to provide a coil bobbin with an intermediate core for a small electric motor.

(Means for Solving the Problems) The present invention provides an intermediate core having pole teeth standing up on its inner periphery, which is arranged between the two coil bobbins,
The two coil bobbins are integrally molded so as to be connected to each other and spaced apart from the pole teeth of the intermediate core.
The two coil bobbins are entirely sealed with resin.

(Function) The two coil bobbins are integrally molded together with the overlapping intermediate core. Coils for two phases can be wound around the two integrally molded coil bobbins at one time. Since each coil bobbin is sealed with resin except for the pole teeth of the intermediate core, it is maintained in a sealed state.

(Example) Hereinafter, an example of a coil bobbin with an intermediate core for a small electric motor according to the present invention will be described with reference to FIGS. 1 to 4.

In FIG. 1, reference numeral 26 denotes a two-phase coil bobbin that is overlapped, and two intermediate cores 31 are arranged at the overlapping portion of the two-phase coil bobbin 26. Coil bobbin 2 for 2 phases
6 is formed by a tree tooth, but by being formed through a hole formed in each intermediate core 31, the 2
The phase coil bobbin 26 and two intermediate cores 31 are insert-molded in a connected manner.

As shown in FIG. 4, the intermediate core 31 has pole teeth 31a standing up on its inner circumference. The coil bobbin 26 also has pole teeth 31 on the inner circumference of the intermediate core 31.
It is molded at a predetermined distance from a. Terminals 25 are press-fitted onto the upper and lower peripheral edges of the coil bobbin 26, and coils 29 are wound around each of the coil bobbins 26 for two phases.

In this manner, with the terminals 25 press-fitted and each coil 29 wound, the two coil bobbins 26 are entirely sealed by insert molding with the resin 35, forming the coil set 24. terminal 2
A portion of 5 protrudes outward from the resin 35. During insert molding with the resin 35, the resin 35 is inserted between the pole teeth 31a of the intermediate core 31 and the coil bobbin 26.
However, in order to create a space into which the pole teeth 21a of the core 21 and the pole teeth 27a of the case 27, which will be described later, can be inserted, a third mold is used to form the coil set 24.
Since a convex portion that prevents the resin 35 from flowing into the concave portion 35a shown in the figure is formed, the resin 35 does not flow into the corresponding portion and the concave portion 35a is formed.

The core 21 is arranged at the upper end of the coil bobbin 26, and its pole teeth 21a are fitted into the recesses 35a of the resin 35. Similarly, a cup-shaped case 27 that also serves as a core is disposed at the lower end of the coil bobbin 26, and pole teeth 27a formed at the center of the bottom of the case 27 fit into a recess 35a of the resin 35. Positioning of the core 21 with respect to the resin 35 constituting the coil set 24 is performed by fitting a positioning pin 35b integrally formed on the resin 35 side with a positioning hole 21b formed on the core 21 side.

Above the coil set 24, a gearbox is formed by the core 21 and the base plate 22 fitted across the upper inner peripheral edge of the case 27 and the rising portion 35c of the resin 35. The core 21 also serves as a base plate on the lower side of the gearbox, and a gear 33 is rotatably supported between a bearing 32 attached to the core 21 and a bearing 34 attached to the base plate 22. A rotor shaft 28 integrally having a rotor 30 is rotatably supported between the center of the base plate 22 and the bottom center of the case 27. A gear 36 is rotatably supported by a shaft 38 and a gear 37 is rotatably supported by a shaft 39 between the core 21 and the base plate 22, and the rotational force of the rotor shaft 28 is transferred to the gear 33 by appropriately reducing the speed. It has come to be transmitted to

FIG. 2 shows an example of the assembly process of the embodiment of the small electric motor described above. First, as shown in FIG. 2a, a two-phase coil bobbin 26 is formed by insert molding resin together with two stacked intermediate cores 31. Here, the coil bobbin 26 for two phases is connected to a connecting portion 26 formed by a hole in the intermediate core 31.
The coil bobbin 26 and the intermediate core 31 for two phases are not separated. Further, a predetermined interval h is provided between the coil bobbin 26 and the pole teeth 31a of the intermediate core 31.
A sealing resin, which will be described later, is inserted into this space h. Terminal mounting portions 26c are formed at the upper and lower peripheral edges of the coil bobbin 26.

Next, as shown in FIG. 2b, the terminal 25 is press-fitted into the terminal attachment part 26c of the coil bobbin 26 and fixed. A total of four terminals 25 are attached corresponding to two phases of the coil.

Next, as shown in FIG. 2c, two-phase coils 29 are wound. Since the two phases of the coil bobbin 26 are integrally molded and can be handled as one piece, the winding work for the two phases can be performed continuously.

Next, the coil bobbin 26 whose winding has been completed is again insert-molded and sealed with a sealing resin 35 such as unsaturated polyester, as shown in FIG. 2d. At this time, the resin 35 fills the space between the coil bobbin 26 and the pole teeth 31a of the intermediate core 31, but as described above, the recesses 35a are formed between the pole teeth 31a of the intermediate core 31. The pole teeth 21a of the core 21 and the pole teeth 27a of the case 27 explained in FIG. 3 are designed to fit between the pole teeth 31a of the intermediate core 31.

Next, as shown in Figure 2e, the core 2
1. Assemble the main plate 22 and case 27, and further,
The rotor 30 and other rotational force transmission gear trains are assembled to complete the process.

In the embodiment described above, the terminals 25 communicating with the coils of each phase are attached at positions separated from each other in consideration of mutual insulation. Further, the rising portion 35c, which is a part of the sealing resin 35, also serves as a cover for the gearbox.

According to the above embodiment, the sealing resin 35 covers almost all of the coil 29 and the coil bobbin 26, leaving only two connecting wires with the intermediate core 31 on the outer periphery. We can provide good small electric motors. Further, if unsaturated polyester or the like is used as the sealing resin, it is effective in terms of sealing performance because it has extremely good adhesion to metal. In addition, since the coil bobbin 26 for two phases can be handled as one coil bobbin, not only can the coils for two phases be wound in one setup, but also in the entire assembly process.
It can be easily assembled like a phase type motor. Furthermore, since the two-phase coil bobbin and the two intermediate cores are integrally molded, the outer core can be assembled later, so the outer core can be used as a cup-shaped motor case or gearbox base plate.

The small electric motor according to the present invention can be applied to a capacitor motor, a stepping motor, etc.

(Effects of the Invention) According to the present invention, since the two coil bobbins are integrally molded so as to be connected to each other, they are handled in the same way as parts for one phase during the entire winding work of the two coils and the assembly process of the motor. It is easy to assemble, and the cost is low. Further, since a space is provided between the integrally molded coil bobbin and the pole teeth of the core, and the sealing resin is placed within this space, the sealing performance of the entire coil can be improved.

[Brief explanation of the drawing]

FIG. 1 is a vertical cross-sectional view showing an embodiment of a small electric motor according to the present invention, FIG. 2 is a vertical cross-sectional view sequentially showing an example of the assembly process of the same embodiment, and FIG. 3 is an exploded perspective view of the above embodiment. FIG. 4 is a perspective view showing the intermediate core in the above embodiment, FIG. 5 is a longitudinal sectional view showing an example of a conventional small electric motor, and FIG. 6 is a longitudinal sectional view showing another example of a conventional small electric motor. be. 26...Coil bobbin, 29...Coil, 31
...Intermediate core, 31a...Pole tooth, 35...Resin.

Claims (1)

[Claims] 1. In a small electric motor formed by overlapping two coil bobbins wound with coils, an intermediate core having pole teeth standing up on the inner periphery is disposed between the two coil bobbins, and the two coil bobbins are connected to each other. A small electric motor characterized in that the two coil bobbins are integrally molded so as to be spaced apart from the pole teeth of the intermediate core, and the entirety of the two coil bobbins except for the pole teeth of the intermediate core is sealed with resin. Coil bobbin with intermediate core.