JPH11247791A - Axial fan - Google Patents

Abstract

PROBLEM TO BE SOLVED: To dispense with a special component for radiation of heat and to obtain the heat radiating effect with a simple means by fixing a semiconductor element for controlling the winding current of a motor to a disc-shaped bottom inner face of a motor holding cylindrical portion integrally connected with a cylindrical wind tunnel part by a plurality of legs. SOLUTION: A shallow recessed portion is formed on a disc-shaped bottom portion 1-7, and a screw member 8 is used as a securing and fastening means of a semiconductor element 5-2. A point of the screw member 8 is prevented from brought into contact with a name plate 7 affixed as a covering member. A window 1-8 leading inside of the disc-shaped bottom part 1-7 is formed, and a leg connecting a wind tunnel portion of a venturi case 1 with a motor holding cylindrical portion 1-6 comprises a leader line insertion groove 1-5. By bringing and fixing the heating semiconductor element 5-2 to the motor holding cylindrical portion 1-6 integrated with the veturi case made of a metallic member, the radiation can be effectively performed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an axial fan, and more particularly to an axial fan in which a semiconductor element used in a control circuit of a driving motor has an excellent heat radiation effect.

[0002]

2. Description of the Related Art FIG. 5 is a sectional view of an example of an axial fan according to the prior art. In FIG. 5, an impeller 2 is formed on the inner peripheral surface of the cylindrical wind tunnel 1-1 of the venturi case 1 through a small gap.
Is rotatably supported, and the impeller 2 is connected to the venturi case 1 by a plurality of legs 1-4 traversing the wind tunnel, and is driven by an electric motor holding cylindrical portion 1-6 which is formed integrally. The motor 3 is rotated and driven, and a control circuit 5 is provided together with the motor 3 inside the motor holding cylindrical portion 1-6. A semiconductor element 5-2 is used for the control circuit 5, and is usually mounted on a circuit board 5-1 constituting the control circuit 5 as shown in FIG. 5, but with the need for high performance and miniaturization, It is the substance that improvement of the heat radiation effect of the semiconductor element 5-2 is required to be improved.

In FIG. 5, since the control circuit 5 is housed in the motor holding cylindrical portion 1-6 together with the motor 3 in a small space, there is little escape of heat generated by the semiconductor elements 5-2 and the like, and the air inside the motor is held. Easier convection and the addition of heat dissipation fins are the countermeasures, but this is an issue that needs to be improved, especially as miniaturization progresses.

[0004]

In the above-mentioned conventional configuration, in order to satisfy the contradictory requirements of high performance and miniaturization, there is a problem of realizing means having a simple configuration and excellent heat radiation effect.

[0005]

An axial fan according to the present invention comprises a semiconductor element for forming a control circuit and controlling a winding current of the electric motor, and has a cylindrical wind tunnel formed of a metal member. The venturi case and the cylindrical wind tunnel are connected to each other by a plurality of feet and are fixed to the inner surface of the disc-shaped bottom of the motor holding cylinder, which is integral therewith. A U-shaped groove is formed on one side of the window, and the U-shaped groove is fitted with a screw member for fastening and holding a semiconductor element disposed on the inner surface of the disc-shaped bottom. The disk-shaped bottom portion of the motor holding cylinder portion, which is configured to be a mounting portion or is connected to the cylindrical wind tunnel portion by a plurality of feet and forms an integral part, for mounting the semiconductor element on an outer surface thereof. Communicating with the recess and the groove formed in the recess and the foot And a window, together with the semiconductor element is accommodated secured in the recess of the disk-like bottom portion, the window and the grooves are constructed as a through location of the lead line of the control circuit.

[0006] In the above-described configuration, a means having an excellent heat radiation effect can be realized with a simple configuration without obstructing the contradictory requirements for high performance and miniaturization.

[0007]

Embodiments of the present invention will be described below with reference to the drawings. 1 is a front view of a first example of an axial fan according to the present invention, FIG. 2 is an enlarged sectional view of a main part of the example, FIG. 3 is a front view of a second example of the present invention, and FIG. 3 is an enlarged sectional view of a main part of FIG.

A first example shown in FIGS. 1 and 2 shows a semiconductor element which generates heat, which is conventionally mounted on a circuit board 5-1 on the inner surface of a disk-shaped bottom part 1-7 of a motor holding cylindrical part 1-6. The semiconductor device 5-2 that generates heat is abutted and fixed to the motor holding cylindrical portion 1-6 integrated with the venturi case 1 formed of a metal member, thereby effectively dissipating heat. It is possible.

The reason why the shallow recess is formed in the disc-shaped bottom portion 1-7 in this example is that the screw member 8 is used as a fastening means for fixing the semiconductor element 5-2. Consideration is given so that the tip of 8 does not contact the name plate 7 attached as an outer covering member.

A second example shown in FIGS. 3 and 4 is as follows.
In order to improve the workability in the mounting operation, the semiconductor element 5-2 is fixed to the outer surface of the disk-shaped bottom part 1-7 by abutment. In this example, a concave portion 1-10 capable of accommodating the semiconductor element 5-2 outside the disc-shaped bottom portion 1-7,
A window 1-8 connected to the recess 1-10 and through which the lead wire 6 is inserted.
The semiconductor element 5-2 is fixed to the outside of the concave groove 1-10 by a screw member 8, and the terminal of the semiconductor element 5-2 is connected to the circuit board through the window 1-8. It is designed to connect wires. With this configuration, the semiconductor element 5-2 generating a large amount of heat can be retrofitted to the outer surface of the disc-shaped bottom part 1-7.

In each of the above examples, a window 1-8 communicating with the inside of the disc-shaped bottom 1-7 is formed, and connects the wind tunnel 1-1 of the venturi case 1 with the motor holding cylinder 1-6. The foot is provided with a lead wire insertion groove 1-5, and the lead wire insertion passage itself has a conventionally well-known configuration. Then, as described above, after mounting and fixing the semiconductor element 5-2, the name plate 7 is adhered so as to cover the semiconductor, which is also a conventionally well-known configuration in consideration of appearance design.

[0012]

The axial fan according to the present invention uses a part of a venturi case made of a metal member as a semiconductor heat radiating member, thereby eliminating the necessity of using a special member for heat radiating and simplifying the axial fan. The effect that the heat radiation effect of the heat generating semiconductor element can be realized by an appropriate means is brought about.

[Brief description of the drawings]

FIG. 1 is a front view of a first example of an axial fan according to the present invention.

FIG. 2 is an enlarged sectional view of a main part of the example of FIG.

FIG. 3 is a front view of a second example of the axial fan according to the present invention.

FIG. 4 is an enlarged sectional view of a main part of the example of FIG. 3;

FIG. 5 is a cross-sectional view of an example of an axial fan according to the related art.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Venturi case 1-1 Cylindrical wind tunnel part 1-4 Leg 1-5 Groove formed in leg 1-6 Electric motor holding cylinder part 1-7 Disk-shaped bottom part 1-8 Window through which lead-out line of bottom is inserted 1- 9 U-groove formed on one side of window for screw fitting 1-10 Recess for mounting semiconductor element 2 Impeller 3 Electric motor 3-1 Stator 3-2 Rotor 3-3 Rotor shaft 3-4 Rotor hub 4 Bearing 5 Control circuit 5-1 Circuit board 5-2 Semiconductor element 6 Lead wire 7 Name plate 8 Screw member

Claims (4)

[Claims] 1. A venturi case having a cylindrical wind tunnel portion formed of a metal member, an impeller rotatably supported by a plurality of blades opposing an inner peripheral surface of the wind tunnel portion via a small gap, In an axial fan having an electric motor and a control circuit for controlling the electric motor therein for driving the impeller, a semiconductor element for constituting the control circuit and controlling a winding current of the electric motor is provided on the cylindrical fan. An axial flow fan, wherein the axial flow fan is fixedly disposed on a disk-shaped bottom portion of an electric motor holding cylindrical portion which is connected to a wind tunnel portion by a plurality of legs and is integral therewith. 2. A disc-shaped bottom portion of an electric motor holding cylinder portion, which is connected to the cylindrical wind tunnel portion by a plurality of legs to form an integral body, has a window communicating with a groove formed in the leg on an outer surface thereof. 2. The semiconductor device according to claim 1, wherein a semiconductor element is fixed to the inner surface of the disc-shaped bottom portion, and the window and the groove are configured to form an insertion passage of a lead wire of the control circuit. 3. Axial flow fan. 3. A U-shaped groove is formed on one side of the window, and the U-shaped groove is a fitting portion of a screw member for fastening and holding a semiconductor element disposed on an inner surface of the disc-shaped bottom portion. The axial fan according to claim 2, characterized in that: 4. A disc-shaped bottom portion of an electric motor holding cylinder portion which is connected to said cylindrical wind tunnel portion by a plurality of legs to form an integral part, a concave portion for mounting said semiconductor element on an outer surface thereof, and said concave portion and said concave portion. A window communicating with a groove formed in the foot, wherein the semiconductor element is housed and fixed in a concave portion on the surface of the disc-shaped bottom, and the window and the groove serve as a place for inserting a lead wire of the control circuit. The axial flow fan according to claim 1, wherein the axial flow fan is configured as follows.