JPH04126626A - Air blowing device of air conditioner for vehicle - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an air blower used in an air conditioner for a vehicle such as an automobile.

[Prior Art] A conventional blower device, as described in Japanese Patent Publication No. 63-53782, has a centrifugal multi-blade fan fixed to the shaft of an electric motor in a scroll casing downstream of an air introduction device having internal and external air inlets. It is composed of This electric motor has brushes placed on the side opposite the fan.

However, due to improvements in vehicle cabin quietness in recent years, there is a problem in that the brush noise of the electric motor impairs the ride comfort for passengers.

As a countermeasure to this, as in Japanese Utility Model Application Publication No. 62-98458,
Air blowers with brushes placed on the fan side have also appeared.

In either case, the electric motor of the air blower has a structure in which a portion of the air generated by the fan is guided into the electric motor and cooled to reduce the temperature rise inside the electric motor. For this reason, the end bracket of the electric motor is provided with an opening in order to return the introduced wind to the scroll casing.

[Problem to be Solved by the Invention 1] The above-mentioned prior art has a problem in that it does not take into consideration that brush noise is likely to be emitted from the opening of the end bracket into the vehicle interior through the air outlet along with the wind.

The purpose of the present invention is to alleviate this problem.

[Means for solving the problem 1 In order to achieve the above object, the first method is to provide a wall on the mounting foot that fixes the motor to the scroll casing, and this wall has a diameter larger than the outer diameter of the motor body. In addition, the part is smaller than the outer diameter of the fan, and is configured to reduce the gap between the part and the fan. - The second method is when the fan has double blades, by arranging it so that the blade and the blade overlap in the axial direction at a position close to the inner diameter of the blade on the mounting foot side and smaller than the blade inner diameter. The reduction effect is greater than that of the first method.

The third method aims to reduce the number of parts and cost by integrally molding the mounting feet and the wall from synthetic resin instead of manufacturing them separately.

[Effect]

The wall is provided at the location described above. For this reason, the brush sliding noise that is mainly caused by the rotation of the electric motor is caused by the cooling air introduced from the side opposite to the fan passing through the armature and returning into the scroll casing from the opening in the end bracket on the fan side. It is reflected and attenuated by the mounting foot and the wall provided on the mounting foot. , Conventionally, this wall did not exist, so the inside of the scroll casing was directly penetrated from this part.

Especially in the case of fans with sub-blades, the blades and walls overlap in the axial direction of the fan, so the distance that noise travels is longer than when there are no sub-blades.
The sound is reflected by the sub-blades, making it highly effective.

If the mounting feet and wall are manufactured separately, it will take more labor to integrate the two. Therefore, it is obvious that the cost will be lower if the parts are manufactured in one piece.

〔Example〕

Hereinafter, one embodiment of the present invention will be described in detail using the drawings.

FIG. 1 shows a cross-sectional view of the blower, in which an outside air inlet 2 is located on the top wall 1a of a hollow rectangular parallelepiped internal/external air switching box 1, an inside air inlet 3 is located on the side wall 1b, and the inside of the scroll casing 4 is located on the bottom wall IC. A bellmouth-shaped suction port 5 is provided which communicates with the .

Further, inside the inside/outside air switching box 1, there is provided an inside/outside air switching damper 6 for adjusting the opening degree of the inside/outside air inlet 2 and the outside air inlet 3.

On the other hand, a fan 8 attached to a shaft 7a of an electric motor 7 is provided inside the scroll casing 4. The fan 8 is formed by about 40 blades 8a set up on a drum 8b. A stepped portion 9 for housing the bellmouth-shaped suction port 5 is provided on the inlet side of the blade 8a, and a notch is provided at the tip of the inner diameter portion. The axial length of the stepped portion 9 is smaller than the axial length of the ring 8C for maintaining the strength of the blades 8a of the fan 8.

The electric motor 7 cools the inside of the electric motor 7 by passing a cooling hose 10 from a part of the scroll casing 4 to a rotor 71 . Brush device 72. An end bracket 73° having a bearing and having an opening 73a is composed of a mounting leg 74 for fixing the main body of the electric motor 7 to the scroll casing 4, a wall 75 provided on the mounting leg 74, and the like.

At this time, an external power source (not shown) is applied to the electric motor 7 to rotate the rotor 71, thereby rotating the fan 8 attached to the shaft 7a. A portion of the resulting wind is introduced from the scroll casing 4 through the cooling hose 10 into the electric motor 7, and the rotor 71. The brush device 72 and the like are cooled down and returned to the scroll casing 4 through the opening 73a of the end bracket 73. At this time, mainly the sliding noise between the brushes of the brush device 72 and the commutator of the rotor 71 is emitted to the electric motor 7 along with the wind. It is then transmitted to the scroll casing 4 through a slight gap between the drum 8b of the fan 8 and the wall 75 of the mounting foot 74. However, most of the noise is reflected by the wall 75, so the noise is reduced and goes out.

FIG. 2 shows an example of further increasing this effect.

That is, the fan 8' has a structure in which the auxiliary blade 8d is also provided on the side of the mounting leg 74 of the drum 8b, and in this case, the fan 8'
may be opposed to the auxiliary blade 8d through a gap, but the auxiliary blade 8d and the wall 75 may overlap in the axial direction (
(0 dimension in the figure represents the wrap length), the noise propagation distance becomes longer and the noise is further reduced by being reflected by the auxiliary blade 8d.

Although a structure is known in which the mounting legs 74 and the wall 75 are made separately and made into a body, it is cost effective and most effective to make them integrally made of synthetic resin. Moreover, since the mounting feet have a large diameter, synthetic resin with a low specific gravity can be expected to have the effect of reducing weight compared to metal.

Further, the shape of the mounting leg 74 may be bent toward the auxiliary blade 8d as shown in FIG. (In the figure, the arrows indicate the flow of cooling air.) When the diameter of the mounting foot is made small, the wall will be made in the scroll casing.

This wall also has other effects as described below.

1. Becomes a reinforcing material. In particular, in the case of synthetic resin, the mechanical strength is inferior to that of metal, so this wall serves as a reinforcing material and improves the strength of the mounting foot that holds the weight of the electric motor.

2. In the case of a vehicle air conditioner, outside air is guided into the vehicle interior through the outside air inlet. Generally, for vehicles, structural considerations are made to prevent the scroll from entering the scroll casing 4. However, there is no specific measure against powder snow, which passes through the air introduction device together with air and enters the scroll casing 4. After entering the water, it melts and becomes water. At this time, it is possible to prevent water from entering the motor due to the second wall 75.

In particular, the electric motor is not installed horizontally with respect to the vehicle, but at a slight angle, and powder snow that has entered through the gap between the fan 8 and the scroll casing is likely to enter the inside of the electric motor through the opening of the end bracket when it melts. If water gets into the motor, the insulation may be destroyed.

[Effects of the Invention] As explained above, according to the present invention, the provision of walls has the effect of reducing noise propagation, and is useful as a noise reduction measure for electric motors operating in narrow spaces such as vehicle air conditioners. As one, it is extremely effective.

[Brief explanation of drawings]

The figures show examples of the present invention, in which Figure 1 is a cross-sectional front view of a blower using a centrifugal fan with only main blades, Figure 2 is a cross-sectional front view of a blower using a centrifugal fan with auxiliary blades, and Figure 3 is a cross-sectional front view of a blower using a centrifugal fan with auxiliary blades. The figure is a cross-sectional front view of the blower device showing a modification of the mounting foot of FIG. 2. 1...Inside/outside air switching box, 10...Cold part hose, 7...
・Electric motor, 72... Brush device, 73... End bracket, leather 1 Figure 2 Figure '15: J, f dirt 3 Ward 75;!

Claims (3)

[Claims] 1. In a blower device having a centrifugal multi-blade fan that introduces air into the scroll casing through an internal/external air switching box having an internal/external air inlet, the electric motor driving the centrifugal multi-blade fan (hereinafter referred to as "fan") is of a forced cooling type. , and a wall is formed on the mounting leg of the electric motor at a portion that is larger than the outer diameter of the electric motor and smaller than the outer diameter of the centrifugal multi-blade fan. 2. 2. The blowing device for a vehicle air conditioner according to claim 1, wherein when the centrifugal multi-blade fan has double blades, the wall is provided with a smaller diameter than the inner diameter of the blades. 3. 2. The blower device for a vehicle air conditioner according to claim 1, wherein the mounting foot and the wall are integrally molded from synthetic resin.