JPH01252138A - Fan motor - Google Patents

Abstract

PURPOSE:To reduce the size and to enable highly efficient cooling, by forming a motor holding board constituting a portion of fan casing of material having high thermal conductivity and fixing a motor thereto thereafter fixing a motor drive circuit section to the motor holding board. CONSTITUTION:A suction port 11, an air supply port 12 and a motor fixing opening 13 are made respectively through the upper face, the side face and the under face of a fan casing body 1. A motor holding board 4 made of material having high thermal conductivity and fixed with a motor 2 having an impeller 3 is mounted on the opening 13. The motor holding board 4 comprises a flange section 42 and a secured section 41, and fixed through a packing 14 to the opening 13. A motor drive printed board 5 and a power transistor 51 are fixed to the motor holding board 4. By such arrangement, the size of fan motor is reduced and efficient cooling is achieved. Such motor is preferably employed in a vehicle air-conditioner.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to an improvement of a blower motor suitable for use in a small blower of an automobile air conditioner.

<Prior art> Some small blowers used in automobile air conditioners have a motor driven by a drive circuit using a power transistor, etc., but this type does not require any particular cooling. Generally, the control circuit portion is installed in a separate location, such as in the vehicle interior, and parts that generate a large amount of heat, such as power transistors, are placed in a ventilation system duct to cool these parts.

<Problem to be solved by the invention> In the above structure, the structure of the ventilation system duct is complicated, and the connection structure between the control circuit section and the parts in the ventilation system duct is also complicated, and it takes time and effort to assemble. Problems such as high cost arose.

The present invention has been made in view of these problems, and aims to provide a blower motor that has an in-cylinder structure and can effectively cool the motor drive circuit section.

<Means for Solving the Problems> In order to achieve the above-mentioned object, in the present invention, a motor holding plate is attached to the motor, and this motor holding plate is attached to the motor mounting opening of the casing body. In a blower motor in which the casing is constituted by a motor holding plate and a motor holding plate, the motor holding plate is formed entirely or partially using a material with good thermal conductivity, and the motor drive circuit portion that requires cooling is The motor is temporarily attached to hold it.

<Function> Since the casing is composed of the motor holding temporary and the casing body, the wind inside the casing also hits the motor holding plate during operation, thereby cooling the motor holding plate. Therefore, the motor holding plate also functions as a heat sink, that is, a heat sink for the motor drive circuit section attached thereto, and the motor drive circuit section is effectively cooled.

<Example> Next, an example in which the present invention is applied to a centrifugal blower will be described.

In the schematic structural diagram of FIG. 1, l is the casing body of the blower, 2 is the motor, 3 is the impeller fixed to the output shaft of the motor 2, and the casing body l has an air intake port on the top surface! l,
An air supply port 12 is provided on the side surface, and an opening I3 for attaching the motor is provided on the bottom surface, and the opening I3 for attaching the motor is considerably larger in size than the outer diameter of the motor 2. Reference numeral 4 denotes a motor holding plate, which is composed of a fixing part 41 for holding the outer peripheral part of the motor 2 and a flange part 42 formed around it. It is larger than the mounting opening 13 and completely covers the motor mounting opening 13 when mounted to the casing body 1 via the packing 14, thereby forming the casing 10 together with the casing body 1. 5 is a motor drive circuit section such as a printed circuit board attached to the motor holding plate 4; 51 is a power transistor of the motor drive circuit section 5;

The above-mentioned blower is constructed by attaching the motor 2 to the motor holding temporary 4, attaching the impeller 3 to the motor unit 6 after completing the necessary wiring, and attaching this to the casing body l. A top view of the motor unit 6 is shown in FIG. 3. The motor holding plate 4 is made by pressing, for example, an iron plate, and the flange portion 42 has approximately 374 mm in diameter for the purpose of reinforcing it and increasing the heat dissipation area.
A plurality of arcuate convex portions 43 are formed around the circumference, and a plurality of notched holes 44 for mounting screws to the casing body I are provided on the outermost circumference. The part where the convex part 43 is not provided is the circuit mounting part 45, and the motor drive circuit part 5 and the power transistor 51 are mounted here, and the Franz part 4
A lead wire 52 is led out from the back surface of 2.

This embodiment is constructed as described above, and when the motor 2 is driven to rotate the impeller 3, the air sucked in from the intake port 11 is accelerated by the impeller 3 within the casing lO, and the air is It is discharged from 12. Since the motor holding plate 4 constitutes a part of the casing lO, the internal airflow also hits the motor holding plate 4 and cools it, so the motor holding plate 4 is connected to the motor drive attached to it. It acts as a heat sink for the circuit section 5 and the power transistor 51, and effectively cools the motor drive circuit section 5 and the power transistor 5I.

The power transistor 51 may be mounted directly on a large area surface or in a posture in contact with the motor holding plate 4 as shown in FIG. 4(a), or may be mounted with fins as shown in FIG. 4(b). The heat radiation effect will be even better if it is attached via an auxiliary heat radiation plate 46 or if heat radiation fins 47 are provided on the motor holding plate 4 as shown in (c).

Since the heat dissipation effect described above also changes depending on the location of the motor holding plate 4, it is desirable that the best mounting position for the power transistor that requires the most cooling be selected through experiments on the vehicle surface.

FIG. 5 and subsequent figures show an example of experimental results regarding the mounting position of this power transistor.

The experiment was carried out using three power transistors 51a, 51b and 51c arranged at regular intervals, as shown in FIG.
As shown in a), (b), and (c), the mounting position with respect to the air supply port 12 was changed in three ways and the temperature was measured. Note that the arrow indicates the direction of the wind inside the casing IO. Figure 6 shows the average value of the maximum temperature at each position and the temperature at the maximum speed, and the lowest temperature is when the air outlet is placed near the air supply port 12 as shown in Figure 5 (a). Position c) was the next best result. Also, Fig. 7(a) and Fig. 7(b)
and FIG. 7(c) are graphs of the temperatures of individual power transistors at positions (aXb) and (c) in FIG. 5, respectively, and each broken line in the figure indicates the temperature of the transistor with the same mark in FIG. Each shows the temperature.

In the embodiment, the power transistor 51 and the like are installed inside the motor holding plate 4, that is, inside the casing, but they may be installed outside the motor holding plate 4 if necessary. Since the heat dissipation effect is similarly exhibited by the motor holding plate 4, the motor drive circuit section 5
Thus, a sufficient cooling effect on the power transistor 51 can be obtained.

<Effects of the Invention> As is clear from the above-mentioned embodiments, the present invention provides a motor holding plate that constitutes a part of the casing of the blower, attaches the motor to the casing body via this motor holding plate, and cools the motor. The motor drive circuit section that requires this is attached to the motor holding plate, and the motor holding plate is used as a heat sink.

Therefore, the structure of the ventilation duct does not become complicated unlike in the past, where parts that generate a lot of heat are placed inside the ventilation duct, and the wiring is simplified because it does not need to extend all the way to the ventilation duct and only needs to reach the motor. Moreover, since the motor holding plate can be attached to the motor and the motor unit can be compactly assembled with the specified wiring, assembly is easier and workability is improved. It is possible to downsize and reduce the cost of small blowers used in devices and the like.

[Brief explanation of the drawing]

FIG. 1 is a schematic structural diagram of an embodiment of the present invention, FIG. 2 is a side view of the motor unit, FIG. 3 is a top view of the motor unit, and FIGS. Figure 4 (c) is a diagram showing an example of the mounting structure of the power transistor, and Figure 5 (a)
, FIG. 5(b), and FIG. 5(C) are outline diagrams of the experiment regarding the mounting position of the power transistor, and FIG. 6 and FIG. 7(a).
), FIG. 7(b), and FIG. 7(c) are graphs showing the experimental results, respectively. ! ...Casing body, 2...Motor, 3.
... Impeller, 4... Motor holding plate, 5
...Motor drive circuit section, 6...Motor unit, 1
0...Casing, 13...Motor mounting opening, 45...Circuit mounting portion, 51.51a, 5 lb, 51c...Power transistor. Patent applicant: Haka Asmo Co., Ltd. Patent attorney: Haka Aoyama (Figure 5, 10)
Figure 5 (bl) Figure 5 (c) Figure 6 Position ■ Figure 7 (0) Figure 7 (b)

Claims (1)

[Claims] (1) Attach the motor holding plate (4) to the motor (2),
By attaching this motor holding plate (4) to the motor mounting opening (13) of the casing body (1), the casing body (1) and motor holding plate (4) can be attached to the casing (
10), the motor holding plate (4) is formed of a material with good thermal conductivity,
The motor drive circuit section (5) that requires cooling is mounted on the motor holding plate (
4) A blower motor characterized by being attached to.