JPH0112542Y2 - - Google Patents

Description

[Detailed Description of the Invention] Industrial Application Field The present invention relates to a small DC motor used in audio equipment and the like.

Conventional configurations and their problems In recent years, in the audio industry, there has been an active trend toward miniaturization, especially thinness, in order to increase added value. As motors become more compact and thinner, there is a strong demand for smaller and thinner motors.

Figure 1 shows the configuration of a conventional small DC motor with a built-in motor control circuit.A is a frame assembly in which a bearing 2 and a field magnet 3 are assembled into a motor body 1, and B is a synthetic resin bracket 4. Bracket assembly in which brush 5 and bearing 6 are incorporated; C is circuit component assembly in which circuit component 8 is incorporated in control circuit board 7; D is armature assembly in which shaft 9, core 10, winding 11, and commutator 12 are incorporated. These are covered by a shield case 13.

In the above configuration, the circuit component 8 has a conductor 15 formed on the lower side of the control circuit board 7 from the component mounting surface through the component mounting hole 14 provided in the control circuit board 7.
The terminal portion of the brush 5 protruding from the bracket 4 is electrically connected to the conductor 15 of the control circuit board 7 by solder 16 through the component mounting hole 14 in the same manner as the circuit component 8.

However, in this configuration, the control circuit board 7 to which the circuit components 8 and the brush 5 are electrically connected
Since the conductor 15 is provided outside the control circuit board 7, a large amount of space is required between the conductor 15 and the shield case 13, making it difficult to reduce the thickness of the conductor 15. In addition, since the bracket 4 is made of synthetic resin, it needs to be covered with a shield case 13, resulting in a large number of parts and high costs.

Purpose of the invention The present invention was made in view of the above-mentioned drawbacks of the conventional technology, and aims to make the motor smaller and thinner.
The purpose is to improve the shielding effect.

Structure of the invention The invention consists of a metal-based control circuit board incorporating circuit components, which is used in combination with the bracket of the motor body, and electrical connection between the circuit components, the mounting surface of the brush, and the conductor. The surface is on the same side as the motor body (inner surface side of the motor body) in order to reduce the thickness and improve the shielding effect.

DESCRIPTION OF EMBODIMENTS An embodiment of the present invention will be described below with reference to the accompanying drawings. Note that functional parts that are the same as those in the conventional configuration described above are given the same numbers, and their explanations will be omitted. In the figure, the frame assembly A and the armature assembly D have the same structure as in the past, but in the present invention, they have a structure that serves both as a bracket assembly and a circuit component assembly. That is, the control circuit board in which the circuit component 8 is incorporated is composed of a metal base control circuit board 17 insulated on both sides with insulating layers 18 and having a conductor 19 formed on the motor main body side (upper side). Motor body 1 so as to cover the end opening of
It is attached by caulking.

In addition, the insulating substrate 20 made of synthetic resin has a bearing holder 21 to which the bearing 6 is attached and a brush holder 22 to which the brush 25 is attached. An engaging pin 23 that is fixedly fixed is integrally provided. Furthermore, the insulating substrate 20 includes large electronic components,
For example, it has an arm portion 26 that also serves as a support for positioning and connecting the variable resistor 8a with solder 16, and a support for preventing damage due to torque when rotating the slider 8b for adjusting the rotation speed. The brush 25 has a wedge-shaped terminal portion 25a for engaging with the brush holding portion 22 of the insulating substrate 20, and a protruding portion 25b for an electrode that also serves to fix the insulating substrate 20.
and is connected to the conductor of the insulating substrate 20 with solder.

Effects of the Invention As is clear from the above configuration, according to the present invention, the control circuit board incorporating circuit components is constructed of a metal-based control circuit board and is used together with the bracket of the motor body, and the circuit components and brush The mounting surface of the motor and the electrical connection surface of the conductor are on the same side, and the circuit section can be mounted on the same conductor surface on the inner surface of the motor, which is highly effective in improving shielding performance and heat dissipation. , the motor can be made smaller and thinner.

[Brief explanation of the drawing]

Fig. 1 is a structural cross-sectional view of a motor according to a conventional example, Fig. 2 is a structural cross-sectional view of a motor according to an embodiment of the present invention, and Fig. 3 a, b, and c are plan views and front cross-sections of an insulating substrate according to the present invention. Figures and side sectional views of main parts,
4a and 4b are partially enlarged sectional views of FIG. 2, and FIG. 5 is an exploded perspective view showing the relationship between the brush and the insulating substrate according to the present invention. DESCRIPTION OF SYMBOLS 1...Motor body, 6...Bearing, 8...Circuit components, 16...Solder, 17...Metal base control circuit board, 18...Insulating layer, 19...Conductor, 20...
Insulating substrate, 21...bearing holding part, 22...brush holding part, 23...engaging pin, 24...retaining hole, 25
... Brush, 25b ... Electrode protrusion.

Claims (1)

[Claims for Utility Model Registration] (1) An engagement that is fixed to the inner surface of a metal-based control circuit board that covers the end opening of the motor body by being thermally melted and fixed after passing through an engagement hole provided in the control circuit board. An insulating substrate having pins is attached, a bearing holding portion and a brush holding portion are provided on this insulating substrate, and the brush held by the brush holding portion of this insulating substrate is flush with the conductor portion formed on the inner surface of the control circuit board. A small DC motor connected by soldering at the connecting electrode protrusions. (2) A small DC motor according to claim 1 of the Utility Model registration claim, in which the brush is provided with a wedge for preventing the brush from coming off, which engages with the brush holding portion of the insulating substrate. (3) A small DC motor according to claim 1 of the utility model registration claim, in which a holding portion for electronic components is provided on an insulating substrate.