JPH09240249A - Blower fan motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To minimize vibration noise transmitted to an interior and dust passing through a cooling wind discharge port while maximally suppressing deterioration of a brush due to heat. SOLUTION: In a vehicle air conditioning blower fan motor provided with a brush, case bodies 21, 26, 27, in each of which a cooling wind inlet EN is formed on one end side while a cooling wind outlet EX is formed on the other end side, and a brush 23 which is supported by means of a brush base 22 fixed in these case bodies so as to be brought into pressure contact with a commutator 25 integrated with a rotary shaft 24, are provided, while a fan is installed in the rotary shaft 24 protruded from the other end sides of the case bodies. The brush 23 is supported on the cooling wind inlet EN side of the brush base 22, while an opening area of the cooling wind outlet EX is set to be 7-15% of the maximum opening area which can be formed on the other end sides of the case bodies.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a blower fan motor used in a vehicle air conditioner.

[0002]

2. Description of the Related Art As a conventional blower fan motor of this type, those shown in FIGS. 9 and 10 are known. In FIGS. 9 and 10, reference numeral 1 is a bottomed, substantially cylindrical body case, and an upper bracket 5 is attached to cover the upper opening 1a. The bracket 5 has a pair of brushes 3 (only one is shown) via the brush base 2.
Are supported so as to face each other, and the tips of the brushes 3 are pressed into contact with the commutator 5 that is integral with the rotating shaft 4 supported by the main body case 1. One end of the rotating shaft 4 is projected from the upper end of the upper bracket 5, and a fan (not shown) is attached here. When a coil (not shown) is energized via the brush 3 and the commutator 5, the rotating shaft 4 rotates and the fan rotates, whereby external air or internal air is guided to the cooling unit side (not shown). The blower fan motor of this form is excellent in workability in assembling because the components housed inside can be stacked and assembled.

On the other hand, in this type of blower fan motor,
Since the brush 3 slides on the commutator 5 during driving, the sliding frictional heat heats the brush 3. Therefore, the cooling air inlet EN is provided in the lower bracket 7 that covers the lower opening 1b of the body case 1, while the upper end opening 1 of the body case 1 is provided.
An air outlet EX is provided in the upper bracket 6 that covers a, and a part of the air blown by the fan is introduced into the main body case 1 from the cooling air inlet EN to contribute to the cooling of the brush 3 and the like, and then the air is exhausted. It is designed to be discharged to the outside from the exit EX.

[0004]

In the conventional blower fan motor, since the brush 3 is supported on the upper part of the brush base 2 as shown in FIG. 10, the cooling efficiency of the brush 3 is poor and the brush 3 is sufficiently cooled. In order to do so, it is necessary to increase the flow rate of cooling air. Therefore, the opening area of the cooling air discharge port EX is made relatively large, about 25% of the area of the main body case upper opening 1a, to improve the flowability of the cooling air. However, if the opening area of the exhaust port EX is increased, the noise generated when the brush 3 slides on the commutator 5 is greatly transmitted to the inside of the vehicle, causing the passenger to feel uncomfortable and the dust passing through the exhaust port EX. Since it is not suppressed, it adversely affects the cleaning of the passenger compartment.

An object of the present invention is to provide a blower fan motor in which deterioration of the brush due to heat is suppressed as much as possible and sliding noise transmitted through the cooling air exhaust port to the passenger compartment and dust passing through the exhaust port are suppressed. To do.

[0006]

FIG. 1 shows an embodiment of the present invention.
Describing in association with 3 to 3, the present invention relates to the casings 21, 26, 27 in which the cooling air introduction port EN is formed on one end side and the cooling air discharge port EX is formed on the other end side. A rotating shaft that is supported by a brush base 22 that is fixed to the other end of the housing and that includes a brush 23 that is pressed into contact with a commutator 25 that is integral with the rotating shaft 24 and that protrudes from the other end of the housing. It is applied to a blower fan motor with a brush for vehicle air conditioning in which a fan 30 is attached to 24. And the brush 23
Is supported on the surface side of the brush base 22 facing the cooling air inlet EN, and the opening area of the cooling air outlet EX is 7 to 15% of the maximum opening area that can be formed on the other end side of the housing. This solves the above problems. Claim 2
Of the present invention has a cylindrical main body case 21 and a bracket 26 attached so as to cover an opening of the main body case on the fan mounting side, and the cooling air discharge port EX is attached to the bracket 26.
It is formed in. According to the third aspect of the invention, the cooling air discharge port is composed of a plurality of holes. According to a fourth aspect of the present invention, a plurality of holes are formed on a concentric circle centered on the rotation axis at predetermined angular intervals.

[0007] In the section of the means for solving the above-mentioned problems, which explains the configuration of the present invention, the drawings of the embodiments are used to facilitate understanding of the present invention. However, the present invention is not limited to this.

[0008]

According to the present invention, since the brush is supported on the side of the cooling air introducing port of the brush base, the cooling efficiency of the brush is improved as compared with the conventional case in which the brush is supported on the upper part of the brush base. Even if the opening area of the cooling air outlet is small, the deterioration of the brush due to heat can be suppressed as much as possible. Moreover, since the opening area of the cooling air discharge port is set to 7 to 15% of the maximum opening area that can be formed on the other end side of the housing,
It is possible to suppress the sliding noise transmitted to the vehicle interior and dust passing through the discharge port.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a schematic diagram showing a blower unit of a vehicle air conditioner according to the present embodiment. A blower fan motor 100 is attached to the lower portion of the blower unit BU, and a fan 30 is attached to the rotary shaft 24 thereof. Blower fan Fan motor 100 for fan 30
When is rotated, outside air or inside air (air inside the vehicle) is introduced into the blower unit BU and guided to a cooling unit (not shown). In addition, a part of the air is guided to the lower part of the blower fan motor 100 via the duct 11,
00 contributes to cooling of the inside.

FIG. 2 is a top view showing the structure of the blower fan motor 100, FIG. 3 is a vertical cross-sectional view thereof, and FIG. 4 is an enlarged view of essential parts showing a state in which the fan 30 is attached. Reference numeral 21 denotes a substantially cylindrical main body case, and a lower bracket 27 is attached so as to cover a part of the lower end opening 21b of the main body case 21. A portion of the opening 21b that is not covered with the bracket 27 serves as a cooling air inlet EN. The rotary shaft 24 is rotatably supported in the main body case 21, and a cylindrical commutator 25 having conductors fixed to the peripheral surface at predetermined intervals is attached to the rotary shaft 24. Commutator 25
A coil (not shown) is connected to each conductor.

A bracket 27 is attached to the upper opening 21a of the main body case 21, and a pair of brushes 23 oppose each other under the brush base 22 fixed to the bracket 27 and are movable in the radial direction of the bracket 27. Installed on. Each brush 23 has a brush base 22.
Commutator 2 via a spring 28 (FIG. 4) provided between
The tip end is in contact with the peripheral surface of the commutator 25 by being urged to the 5 side. Further, as shown in FIG. 2, a plurality of cooling air discharge holes EX are formed in the upper bracket 27 on a concentric circle centered on the rotation shaft 24 at predetermined intervals. When the area of each hole EX is S0, the total number of holes EX is n, and the area of the upper opening of the main body case 21 is Sa,

## EQU1 ## The opening area ratio α is set so that α = (S0 × n) / Sa = 7 to 15 (%). This α =
7 to 15 (%) is a value derived by the experiments of the present inventors, the details of which will be described later.

In the blower fan motor 100 configured as described above, the rotating shaft 24 is rotated by energizing the coil through the brush 23 and the commutator 25, and the fan 30 attached to the rotating shaft 24 is rotated. . As described above, the rotation of the fan 30 introduces the outside air or the inside air into the blower unit BU and guides it to a cooling unit (not shown).
And is guided to the lower part of the blower fan motor 100 as a cooling air. This cooling air is supplied to the blower fan motor 100.
Is introduced into the main body case 21 from the cooling air introduction port EN and is discharged to the outside from the cooling air discharge hole EX. When the cooling air flows through the main body case 21, members such as the brush 23 are cooled. In particular, in the present embodiment, the brush 23 is attached to the lower portion of the brush base 22, so that the cooling efficiency of the brush 23 is better than in the conventional case.

By the way, as described in the prior art, the blower fan motor 100 of this kind has a problem of dust and noise passing through the discharge hole EX in addition to the heating of the brush 23.
All of these problems are affected by the ratio α between the area of the upper opening 21a of the main body case 1 and the total opening area (actual opening area) of the cooling air discharge holes EX. Therefore, the inventors obtained various results by obtaining the optimum opening area ratio α and obtained the results shown in FIGS. 5 to 7.

In FIG. 5, the horizontal axis represents the opening area ratio α and the vertical axis represents the temperature of the brush 23. As you can see from the figure,
When the opening area ratio α is 7% or more, the cooling effect is high and the brush temperature is so low as to be unproblematic. Therefore, it is desirable that the opening area ratio α be 7% or more in consideration of safety.

In FIG. 6, the horizontal axis represents the opening area ratio α, and the vertical axis represents the amount of dust passing through the discharge port EX. As can be seen from the figure, the amount of dust passing through the opening area ratio α is 15%.
It is relatively small below, but rises sharply when it exceeds 15%. Therefore, it is desirable that the opening area ratio α be 15% or less.

In FIG. 7, the horizontal axis represents the opening area ratio α, and the vertical axis represents the noise level (noise in the passenger compartment) generated by the sliding of the brush 23 and the commutator 25. As can be seen from the figure, the noise is generated when the opening area ratio α is about 5% and increases linearly with the increase of α thereafter, but the noise is considerably small around α = 7%. The present inventors repeated the same noise test using the blower fan motor (α = 7%) of this embodiment and the conventional blower fan motor (α = 25%), and as a result, as shown in FIG. The frequency distribution was obtained. According to this, the motor according to the present embodiment has lower noise as a whole, and the noise reduction of about 14% can be achieved even when the average values are compared. In particular, in the present embodiment, since the plurality of cooling air discharge holes EX are provided on the concentric circles, the strength of the upper bracket that supports the rotating shaft 24 can be increased, and the internal heat can be uniformly discharged, so that the heat resistance can be improved. The above is also advantageous.

In the above embodiment, the body case 21,
The upper bracket 26 and the lower bracket 27 form a housing. The air discharge holes need only satisfy α = 7 to 15%, and the number, shape, arrangement position, etc. of the air discharge holes are not limited to those in the embodiment.

[Brief description of drawings]

FIG. 1 is a schematic view showing a blower unit of a vehicle air conditioner according to an embodiment.

FIG. 2 is a top view of a blower fan motor.

3 is a vertical cross-sectional view of a blower fan motor, in which the left half is a view seen from the direction IIIa in FIG. 2 and the right half is a view seen from the direction IIIb in FIG.

FIG. 4 is an enlarged view of a main part of a blower fan motor.

FIG. 5 is a diagram showing a brush temperature with respect to an opening area ratio α of a cooling air discharge port.

FIG. 6 is a diagram showing the amount of dust passing through the cooling air outlet with respect to α.

FIG. 7 is a diagram showing a noise level for α.

FIG. 8 is a diagram showing a frequency distribution of noise in the embodiment and the conventional blower fan motor.

FIG. 9 is a top view showing a conventional blower fan motor.

10 is a vertical cross-sectional view of the blower fan motor of FIG. 9, where the left half is from the Xa direction in FIG. 9 and the right half is Xb in FIG.
It is the figure seen from each direction.

[Explanation of symbols]

 21 Body Case 22 Brush Base 23 Brush 24 Rotating Shaft 25 Commutator 26 Upper Bracket 27 Lower Bracket 30 Fan 100 Blower Fan Motor BU Blower Unit EN Cooling Air Inlet EX Cooling Air Discharge Hole

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Kazuhiro Irie 2 Takaracho, Kanagawa-ku, Yokohama, Kanagawa Nissan Motor Co., Ltd. (72) Masashi Arai 2 Takaracho, Kanagawa-ku, Yokohama, Kanagawa Nissan Motor Co., Ltd.

Claims (4)

[Claims] 1. A housing having a cooling air inlet formed at one end and a cooling air outlet at the other end, and a brush base fixed to the other end in the housing. A blower fan motor for a vehicle air conditioner, comprising a rotating shaft and a brush that is pressed into contact with a commutator integrated with the rotating shaft, and a fan is attached to the rotating shaft protruding from the other end side of the housing. The brush is supported on the side of the brush base that faces the cooling air inlet, and the opening area of the cooling air outlet is 7 to 7 of the maximum opening area that can be formed on the other end side of the housing. Blower fan motor characterized by being set to 15%. 2. The housing has a tubular main body case and a bracket attached so as to cover an opening of the main body case on the fan attachment side, and the cooling air discharge port is formed in the bracket. Claim 1 characterized by the above.
Blower fan motor described in. 3. The blower fan motor according to claim 2, wherein the cooling air exhaust port includes a plurality of holes. 4. The blower fan motor according to claim 3, wherein the plurality of holes are formed on a concentric circle having the rotation axis as a center at predetermined angular intervals.