JP2002089485A - Dc motor fan - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize a structure preventing a break of an electronic component constituting a control circuit even if static electricity is applied to the electronic component by hand contact or the like with an external current-carrying terminal. SOLUTION: This DC motor fan has a casing; a DC motor having a stator retained by the casing and a rotator integrated with an impeller; and a control circuit rotationally driving the DC motor, disposed integrally close to the stator. A circuit board constituting the control circuit is mounted with a constant- voltage discharge component. The DC motor fan has a tube-like part or a plate-like member with a bent face electrically connected to the discharge component, a coil spring housed in the tube-like part or the plate-like member, and a springy electroconductive member including a movable bar which directly abuts on the coil spring. The electroconductive member is retained in a full-time pressure contact state with the inner face of the casing.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a DC motor fan, and more particularly to a DC motor fan which integrally holds a DC motor and a control circuit for rotating the DC motor, thereby preventing damage to the control circuit due to static electricity.

[0002]

2. Description of the Related Art FIG. 6 is a sectional view of an example of an axial fan in which an external rotation type motor having a built-in control circuit is used as a driving motor 1. As is well known, the driving motor 1 is supplied with power from an external power supply (not shown) and is rotationally controlled. That is, in this example, the control circuit 6 housed inside the housing 5 communicates with an energizing end (not shown) that penetrates the housing 5 and is exposed outside the housing 5. Since the external current-carrying end is naturally placed in a state where it can be touched, not only normal energization for driving but also static electricity may be applied to the control circuit 6 by touch or the like. There was concern that parts could be damaged.

A control circuit 6 on which many electronic components are mounted includes:
In order to avoid damage due to static electricity during the manufacturing process and mounting process, sufficient care is taken in handling, but in the state after mounting, especially the control circuit itself is placed inside as in this example, The lack of attention to static electricity, in which only the energized terminal could be seen, was a victory.

[0004]

In the conventional structure as described above, there is no concern that the electronic components constituting the control circuit may be damaged due to static electricity applied to the electronic components by touching the external power supply end. I was in a situation where I could not do it.

[0005]

According to the present invention, there is provided a DC motor fan comprising: a DC motor having a housing; a rotor integrally formed with a stator and an impeller held by the housing;
A control circuit that drives the motor to rotate, the control circuit being a DC motor fan that is provided in close proximity integrally with the stator, and a constant voltage discharge component mounted on a circuit board that constitutes the control circuit. And a plate-like member or a tubular portion electrically connected to the constant voltage discharge component and having a bent surface, a coil spring housed therein, and a movable rod directly in contact with the coil spring. A conductive member having a spring property is provided, and the conductive member is provided so as to be always kept in pressure contact with the inner surface of the housing.

[0006]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows a first embodiment according to the present invention. The circuit is electrically connected to a circuit board 6-1 constituting a built-in control circuit 6 by a predetermined wiring pattern (not shown). 4, a conductive member 7 having a spring property, which is formed of a plate-shaped member having a bent surface 7-1 having a spring property, is added. The conductive member 7 is held in a press-contact state with its own resiliency on the inner peripheral surface of the cylindrical portion of the cup-shaped casing 5 made of a metal member, which holds the stator 2 of the DC motor 1. . With such a configuration, although not shown, when static electricity is applied to a current-carrying end outside the housing 5 that communicates with the control circuit 6,
The current is discharged through the current-carrying end, the predetermined wiring pattern of the circuit board, the mounted constant-voltage discharging component, the conductive member having spring properties, and the passage of the housing, so that the electronic components constituting the control circuit 6 can be prevented from being damaged. The constant voltage discharging component 6-2 itself is a well-known component, and the constant voltage discharging component 6-2 is provided by being electrically connected to a dedicated pattern independent of a wiring pattern forming the control circuit 6. It is a well-known means, so that illustration and details are omitted.

FIG. 2 shows a second embodiment of the present invention.
This is an example in which a conductive member 7 having a spring property used in the above is pressed and held on the inner surface of the bottom of the housing 5.

FIG. 4 shows an example of the conductive member 7 having spring properties used in the above embodiment.

FIG. 3 shows a third embodiment of the present invention. Similar to the second embodiment, the conductive member 8 having spring properties is provided so as to be pressed against the inner surface of the bottom of the housing 5. The conductive member 8 having spring properties in the example is not formed of a plate-shaped member, but as shown in FIG. 5, a cylindrical portion 8-1 and a coil spring 8-2 housed therein. It has a movable rod 8-3 that comes into direct contact with the coil spring 8-2, and is held on the inner surface of the bottom of the housing 5 so as to be constantly pushed out by the coil spring 8-2 provided inside. The movable rod 8-3 is provided so that the tip thereof is pressed against the movable rod 8-3.

The means for holding the conductive members 7 and 8 having spring properties which are always held in pressure contact with the housing 5 are electrically connected, and may be arbitrarily soldered or crimped to a predetermined position. However, the holding means itself is a well-known technique,
This does not require novelty.

Further, it is needless to say that the above-described technique of the present invention is not limited to a DC motor fan, but can be applied to various motor control circuits.

[0013]

According to the DC motor fan of the present invention, even if static electricity is unexpectedly applied, a constant-voltage discharge component attached to a circuit board constituting a control circuit and a conductive member having a spring property communicating therewith are provided. Since it is discharged to the housing through the member,
Damage to electronic components due to static electricity can be reliably eliminated.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view of an example according to the present invention.

FIG. 2 is a schematic sectional view of a second embodiment according to the present invention.

FIG. 3 is a schematic sectional view of a second embodiment according to the present invention;

FIG. 4 is a schematic view of an example of a conductive member having a spring property used in the examples of FIGS. 1 and 2;

FIG. 5 is a schematic view of an example of a conductive member having a spring property used in the example of FIG. 3;

FIG. 6 is a cross-sectional view of an example of a prior art DC motor fan according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 DC motor 2 Stator 3 Rotor 4 Impeller 5 Case 6 Control circuit 6-1 Circuit board 6-2 Constant voltage discharge component 7 Conductive member with plate-like spring property 7-1 Bending surface with spring property 8 Conductive member having rod-like spring property 8-1 Cylindrical part 8-2 Coil spring 8-3 Movable rod

Claims (5)

[Claims] 1. A DC motor having a housing formed of a conductive member, a rotor integrated with a stator and an impeller held by the housing, and a control circuit for driving the DC motor to rotate. In the DC motor fan, wherein the control circuit is provided integrally and close to the stator, a constant voltage discharging component is mounted on a circuit board constituting the control circuit, and the constant voltage discharging component is mounted on the circuit board. A DC motor fan having a conductive member having a spring property and electrically connected to the housing, the conductive member being provided so as to be always kept in pressure contact with the inner surface of the housing. . 2. The DC motor fan according to claim 1, wherein the conductive member having spring properties is formed of a plate-shaped member having a bent surface. 3. The conductive member having a spring property includes a tubular portion, a coil spring housed in the tubular portion, and a movable rod directly in contact with the coil spring.
4. The DC motor fan according to claim 1. 4. The conductive member having spring properties is provided so as to be pressed against an inner peripheral surface of a cylindrical portion of a cup-shaped housing. 4. The DC motor fan according to claim 1. 5. The electronic device according to claim 1, wherein the conductive member having a spring property is provided so as to be pressed against an inner bottom surface of the housing facing a circuit board forming a control circuit. The DC motor fan according to any one of the above.