JP5215772B2 - Air conditioner for vehicles - Google Patents

Description

  The present invention relates to a vehicle air conditioner provided with a unit housing that guides and circulates air blown from a blower to an evaporator through a diffuser section.

In the unit housing forming the air flow path, an evaporator and a heater core are sequentially arranged along the air flow direction, and the ratio of the amount of air cooled by the evaporator and the amount of air passing through the heater to the amount of bypass is determined. Air conditioning unit (HVAC (Heating, Ventilating and Air-Conditioning) unit) that controls the temperature of air blown into the vehicle from multiple outlets by adjusting the airflow from the blower that is offset in the lateral direction of the vehicle Or the vehicle air conditioner of the structure which sucks in-vehicle air and blows it to an air-conditioning unit is put into practical use.
In such a vehicle air conditioner, the air blown from the blower is guided to the evaporator inlet passage through the diffuser portion formed in the unit housing, and the direction of the air is changed in the evaporator inlet passage and flows toward the evaporator. (For example, refer to Patent Document 1).

JP-A-9-309320

In the vehicle air conditioner as described above, noise of a specific frequency may be projected in the unit housing in which air flows from the blower.
The present invention has been made based on such a technical problem, and an object of the present invention is to provide a vehicle air conditioner that can suppress generation of noise in a unit housing due to air flowing in from a blower.

As a result of extensive studies by the present inventors based on the above object, it was assumed that noise was generated as follows. That is,
1) In the unit housing, for example, due to a change in the cross-sectional area of the flow path in the diffuser part, pressure fluctuation caused by separation from the inner wall surface of the diffuser part occurs in the air flow blown from the blower.
2) Pressure wave due to pressure fluctuation propagates downstream.
3) The pressure wave is reflected by the inner wall surface of the unit housing located in front of the blowing direction.
4) The reflected wave interferes with the pressure wave. Also, the reflected wave reaches the pressure fluctuation occurrence point of 1).
5) Exciting the occurrence of pressure fluctuations.
This is due to the feedback loop. Of course, direct interference between the pressure wave and the reflected wave is also conceivable. These occur when the pressure fluctuation matches the frequency and phase of the reflected wave.

Up to now, the inner wall surface of the unit housing has been formed in a staircase shape for the purpose of uniforming the wind speed distribution of the air that is blown from the blower and redirected in the evaporator inlet flow path of the unit housing and flows toward the evaporator Such techniques have been proposed (see, for example, Japanese Patent Laid-Open Nos. 2002-144848 and 2003-21936).
However, in these technologies, the inner wall surface of the stepped unit housing faces the air blowing direction from the blower, and the reflected wave is reflected toward the blower, from the viewpoint of noise generation. Is not particularly effective.

The air conditioner for a vehicle according to the present invention made there is a blower unit that sucks outside air or inside air and blows air downstream, and air conditioning that blows air blown from the blower unit into the passenger compartment by adjusting the temperature by a heat exchanger. The air conditioning unit includes a unit housing that guides air blown from the blower unit to a heat exchanger that is offset laterally with respect to the blowing direction from the blower unit. Comprises a diffuser section connected to the blower unit, and an inlet channel section for guiding the wind passing through the diffuser section to the heat exchanger, and the inlet channel section is a set of upper and lower wall surfaces along the heat exchanger. A rectangular opening to which the heat exchanger is fixed, a wall surface that is formed continuously from the diffuser portion so as to face the opening portion, and a wall surface that is formed continuously from the diffuser portion Contiguous with the downstream side of the blowing direction, the air blown from the blower unit and said Rukoto includes a reflective surface for reflecting the heat exchanger side.
In this way, by reflecting the air blown from the blower unit to the heat exchanger side by the reflecting surface, it is possible to avoid the wind sent from the blower unit being reflected back to the blower unit side.

For this reason, it is preferable to incline a reflective surface to the heat exchanger side with respect to the surface orthogonal to the ventilation direction from a ventilation unit into a unit housing.
The reflecting surface may be a curved surface that is convex toward the inside of the unit housing.

  On the inner peripheral surface of the unit housing, a convex wall that is continuous along the air blowing direction from the air blowing unit and protrudes toward the heat exchanger side is formed. It can also be a wedge shape that gradually expands toward the downstream side.

  According to the present invention, the pressure wave propagated from the blower unit is reflected by the reflecting surface to the heat exchanger side, thereby preventing the pressure wave propagated from the blower unit from being reflected back to the blower unit side. it can. As a result, even if a pressure fluctuation occurs in the unit housing, it is possible to prevent interference due to reflection of the pressure wave and to suppress the generation of noise due to the pressure fluctuation.

Hereinafter, the present invention will be described in detail based on embodiments shown in the accompanying drawings.
FIG. 1 is a diagram for explaining a configuration of a vehicle air conditioner 10 according to the present embodiment.
As shown in FIG. 1, a vehicle air conditioner 10 accommodates a blower unit 20 that sucks outside air or inside air and blows it downstream, an evaporator (heat exchanger) 30 and a heater core 40 (heat exchanger). And an air conditioning unit 50 that regulates the temperature of the air blown from the blower unit 20 and blows it out into the passenger compartment.

  The blower unit 20 includes a blower 21 with a built-in fan 21a, and a blower unit 22 that sends wind in a tangential direction from the blower 21 by turning of the fan.

Both ends of the unit housing 50H of the air conditioning unit 50 are open, one end is connected to the air blower 22, and the evaporator 30 and the heater core 40 are accommodated at the other end. The unit housing includes a diffuser portion 51 connected to the blower portion 22 and an inlet flow passage portion 52 that guides the wind that has passed through the diffuser portion 51 to the evaporator 30 and the heater core 40.
Here, the evaporator 30 and the heater core 40 each have a rectangular panel shape, along a plane parallel to the blowing direction from the blowing unit 22 (in the direction of arrow A in FIG. 1) and from the center of the blowing unit 22. It is arranged offset to the side.

  As shown in FIG. 2A, the diffuser portion 51 is formed so that its cross-sectional area gradually increases from the air blowing portion 22 side toward the inlet flow passage portion 52 side. The direction of expansion of the cross-sectional area of the diffuser portion 51 coincides with the height direction of the evaporator 30 and the heater core 40.

The inlet channel portion 52 has a function of changing the flow direction in order to apply the wind sent from the blower portion 22 to the evaporator 30 and the heater core 40.
For this reason, the inlet channel 52 is opposed to the upper and lower wall surfaces 52a and 52b along the evaporator 30 and the heater core 40, the rectangular opening 52c to which the evaporator 30 and the heater core 40 are fixed, and the opening 52c. A wall surface 52d formed continuously from the portion 51.
The opening 52c has a length and a height corresponding to the height and width dimensions of the evaporator 30 and the heater core 40.

Here, in the wall surface 52d, the upstream side in the blowing direction A is along the blowing direction A from the blowing unit 22, and the downstream side in the blowing direction A is as shown in FIG. A reflection surface 60A is formed for reflecting the wind sent out from the head toward the opening 52c.
The reflection surface 60 </ b> A is formed to be inclined by a predetermined angle θ <b> 1 with respect to the surface X orthogonal to the air blowing direction A from the air blowing unit 22, and reflects the pressure wave propagated from the air blowing unit 22 to the opening 52 c side. . Here, it is preferable that the angle θ1 for inclining the reflective surface 60A with respect to the plane X orthogonal to the air blowing direction A is about 45 ° to 85 °. In the present embodiment, this angle θ1 is 45 degrees, for example. Here, what is important in providing the reflective surface 60A is not only to incline the reflective surface 60A, but also in the vicinity of the reflective surface 60A, at a position where the wind sent from the blower 22 directly hits, orthogonal to the blowing direction A. This is because no plane is formed. Therefore, it is preferable to provide the reflective surface 60A over the entire region where the wind sent from the blower 22 directly hits.

  Thus, by providing the reflective surface 60A that reflects the pressure wave propagated from the air blower 22 toward the opening 52c in the inlet flow passage 52, the pressure wave propagated from the air blower 22 is on the air blower 22 side. It is possible to avoid reflection and return. Thereby, in the unit housing 50H, for example, due to a change in the cross-sectional area of the flow passage in the diffuser portion 51, the flow of air blown from the blower unit 20 is caused by separation from the inner wall surface of the diffuser portion 51, etc. Even if this occurs, interference due to reflection of the pressure wave can be prevented. As a result, it is possible to suppress the generation of noise due to pressure fluctuation.

By the way, about the reflective surface 60A, the variation as shown below can be considered.
In the wall surface 52d shown in FIG. 3, a reflection surface 60B inclined by an angle θ2 with respect to the surface X orthogonal to the air blowing direction A is formed on the upstream side in the air blowing direction A, and on the downstream side in the air blowing direction A. A reflective surface 60C that is inclined by an angle θ3 with respect to the surface X orthogonal to the blowing direction A is formed continuously to the reflective surface 60B.
Here, angle θ2> angle θ3.

  By doing in this way, the effect similar to the case of the said FIG. 1 can be acquired. Further, by making a plurality of reflecting surfaces 60B and 60C continuous, the pressure wave propagated from the blower unit 22 to the inlet channel portion 52 is reflected at different angles by the respective reflecting surfaces 60B and 60C, so that it is wider. It becomes possible to reflect uniformly over a range.

  Here, in the example of FIG. 3, the two reflecting surfaces 60B and 60C having different inclination angles are formed on the wall surface 52d, but it is also possible to use three or more reflecting surfaces. Moreover, it is possible to form a concave surface by continuously forming a large number of reflecting surfaces having different inclination angles.

In the wall surface 52d shown in FIG. 4, the upstream side in the air blowing direction A is along the air blowing direction A from the air blowing unit 22, and the pressure wave propagated from the air blowing unit 22 is downstream in the air blowing direction A. A reflection surface 60D that reflects the light toward the opening 52c is formed.
The reflection surface 60D is formed by a curved surface that is convex toward the blower 22 side.

  By doing in this way, the effect similar to the case of the said FIG. 1 can be acquired. In addition, by making the plurality of reflecting surfaces 60D convex convex surfaces, the pressure waves propagated from the blower unit 22 can be diffused and reflected at various angles to be uniformly reflected over a wider range. It becomes possible.

As shown in FIG. 5, as in FIG. 1, the wall surface 52 d has an upstream side in the blowing direction A along the blowing direction A from the blowing unit 22, and a downstream side in the blowing direction A has a blowing direction. A reflection surface 60A that reflects the pressure wave propagated from the portion 22 toward the opening 52c is formed.
Furthermore, the convex wall 70 which continues along the ventilation direction A from the ventilation part 22 is formed in the wall surface 52d. The convex wall 70 has a triangular shape with the wall surface 52d as a base, and the cross-sectional area thereof is a wedge shape that gradually increases from the upstream side in the air blowing direction A toward the downstream side.

  By doing in this way, in addition to being able to obtain the same effect as in the case of FIG. 1 described above, the pressure wave propagated from the blower 22 by the convex wall 70 until it reaches the reflection surface 60A. It is possible to reflect uniformly over a wider range.

In the above embodiment, the configuration of the unit housing 50H of the vehicle air conditioner 10 has been mainly described. However, the configuration of the other parts of the vehicle air conditioner 10 is not limited at all.
In addition, regarding the configuration of the unit housing 50H, actually, in order to avoid interference with other devices, the reflecting surfaces 60A to 60D and the convex wall 70 are completely as shown in FIGS. Although not necessarily formed in a shape, even in that case, the pressure wave propagated from the blower 22 is formed so as to be reflected toward the opening 52c in accordance with the gist of the present invention.
In addition to this, as long as it does not depart from the gist of the present invention, the configuration described in the above embodiment can be selected or changed to another configuration as appropriate.

It is a plane sectional view which shows the structure of the vehicle air conditioner in this Embodiment. (A) is a perspective view which shows an entrance channel part, (b) is a top view which shows the mode of reflection in a reflective surface. It is a perspective view which shows the other example of an inlet channel part. (A) is a perspective view which shows the further another example of an inlet flow path part, (b) is a top view which shows the mode of reflection in a reflective surface. It is a perspective view which shows the other example of an inlet flow path part.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... Vehicle air conditioner, 20 ... Air blow unit, 21 ... Blower, 22 ... Air blower, 30 ... Evaporator (heat exchanger), 40 ... Heater core (heat exchanger), 50 ... Air conditioner unit, 50H ... Unit housing, 51 ... Diffuser part, 52 ... Inlet channel part, 52c ... Opening part, 52d ... Wall surface, 60A, 60B, 60C, 60D ... Reflecting surface, 70 ... Convex wall, θ1, θ2, θ3 ... Angle

Claims (4)

A blower unit that sucks outside air or inside air and blows it downstream, and an air conditioning unit that regulates the temperature of the air blown from the blower unit by a heat exchanger and blows it into the vehicle interior.
The air conditioning unit includes a unit housing that guides the air blown from the blower unit to the heat exchanger that is arranged to be laterally offset with respect to the blowing direction from the blower unit,
The unit housing includes a diffuser portion connected to the blower unit, and an inlet flow path portion that guides the air passing through the diffuser portion to a heat exchanger,
The inlet channel portion is formed by a set of upper and lower wall surfaces along the heat exchanger, a rectangular opening to which the heat exchanger is fixed, and the opening facing the opening continuously from the diffuser portion. And a reflecting surface that is connected to the downstream side in the air blowing direction of the wall surface continuously formed from the diffuser portion and reflects the air blown from the air blowing unit to the heat exchanger side. An air conditioner for a vehicle.   2. The vehicle air conditioner according to claim 1, wherein the reflection surface is inclined toward the heat exchanger with respect to a surface orthogonal to a blowing direction from the blowing unit into the unit housing.   The vehicle air conditioner according to claim 2, wherein the reflecting surface is a curved surface that protrudes inward of the unit housing.   A convex wall is formed on the inner peripheral surface of the unit housing along the air blowing direction from the air blowing unit, and is convex toward the heat exchanger. The vehicle air conditioner according to any one of claims 1 to 3, wherein the air conditioner has a wedge shape that gradually expands from an upstream side to a downstream side in the direction.

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