JPH1044743A - Air conditioner for vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce an occurrence of a noise following the rotation of a cylindrical impeller, maintaining preferable air blowing conditions. SOLUTION: In a casing 11, a rear guide 23 is formed above a cylindrical impeller 13 while a stabilizer 24 is formed below the impeller 13. In this case, the shortest distance on the sit-hole 17 side between the cylindrical impeller 13 and the stabilizer 24 is set at 14 to 24% of the outside diameter of the cylindrical impeller 13, while an angle formed by the straight line, which connects the center of rotation of the cylindrical impeller 13 and the position giving the shortest distance on the spit-hole (17) side between the impeller 13 and the stabilizer 24, and a horizontal plane is set at 38 deg. to 43 deg.. The shortest distance on the inlet-port 16 side between the cylindrical impeller 13 and the stabilizer 24 is set at more than 7% of the outside diameter of the cylindrical impeller 13, while the angle formed by the straight line, which connects the center of rotation of the cylindrical impeller 13 and the position giving the shortest distance on the inlet-port 16 side between the impeller 13 and the stabilizer 24, and the horizontal plane is set at 11 deg. to 15 deg..

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an air conditioner for a vehicle, and more particularly to an air conditioner for a vehicle such as a cooling, heating and air purifier for a rear seat disposed on a ceiling surface of the vehicle.

[0002]

2. Description of the Related Art Conventionally, as a vehicle air conditioner for a rear seat such as a one-box car, for example, there is one having the following configuration provided on a ceiling surface (for example, Japanese Patent Application Laid-Open No. Hei 1-317819). reference).

In this vehicle air conditioner, as shown in FIG. 10, a suction port 2 and a blow port 3 are respectively formed at substantially opposite positions of a casing 1, and a cylindrical impeller 4 is disposed inside. . A stabilizer 5 for forming a predetermined gap with the cylindrical impeller 4 is formed on the lower inner surface of the casing 1. The shape of the stabilizer 5 is very important from the viewpoint of air blowing efficiency and the like when airflow in a substantially linear direction is caused by the cylindrical impeller 4. For this reason, the stabilizer 5 is configured to protrude so as to approach the cylindrical impeller 4 on the suction port 2 side and the outlet 3 side, respectively, and to have a concave portion 6 at an intermediate portion between the cylindrical impeller 4 and the rotation of the cylindrical impeller 4. A straight line connecting the center and each end of the stabilizer 5 is set so that angles a and b formed by a horizontal plane or a vertical plane are within a predetermined range.

[0004]

However, in the vehicle air conditioner, the fin pitch (cross-sectional area through which air can flow) of the evaporator 7 is reduced, and the core thickness (the thickness of a portion through which air passes) is reduced. A surging sound and a whistle sound generated by an increase in ventilation resistance generated when the cooling capacity is improved by performing an increase or the like are not sufficiently considered. In other words, the vehicle air conditioner merely attempts to improve the fan efficiency by setting the angles a and b within a predetermined range, but is insufficient to prevent generation of a whistle sound or a surging sound.

Accordingly, the present invention provides a vehicle air conditioner capable of improving the air blowing performance when the airflow resistance is increased and reducing the noise generated by the rotation of the cylindrical impeller while maintaining a preferable air blowing state. The task is to provide

[0006]

In order to achieve the above object, according to the present invention, in a casing having an inlet and an outlet at substantially opposing positions, a casing is provided so as to be horizontal at right angles to a direction connecting the inlet and the outlet. In the vehicle air conditioner, a cylindrical impeller is provided, a rear guider is formed above the cylindrical impeller, and a stabilizer is formed below the cylindrical impeller, and between the cylindrical impeller on the blow-out port side and the stabilizer. The angle a between a horizontal plane and a straight line connecting the rotation center of the cylindrical impeller and the shortest gap position on the outlet side of the stabilizer; and the cylindrical impeller and the stabilizer on the suction port side. And the angle b between a straight line connecting the rotation center of the cylindrical impeller and the shortest gap position on the suction port side of the stabilizer and a horizontal plane, to prevent whistling noise and surging noise. It is obtained by the possible values. Here, the whistle sound and the surging sound mean sounds in the audible range (about 16 to 20 Hz to 16 to 20 kHz).

The range in which the generation of whistling sound and surging sound can be prevented and an appropriate amount of air can be maintained is determined by the dimension t1.
Is set to 14% or more and 24% or less of the outer diameter of the cylindrical impeller, the angle a is set to 38 ° or more and 43 ° or less, and the dimension t2 is set to 7% or more of the outer diameter of the cylindrical impeller. It is preferable that the angle b is 13% or less, and the angle b is 11 ° or more and 15 ° or less. In this case, the optimum value is the median of each range.

In addition, the stabilizer has a radius of curvature smaller than the radius of the cylindrical impeller at an intermediate portion other than the outlet side and the suction side, centered on a position below the rotation center of the cylindrical impeller. It is preferable that the cylindrical impeller has a concave curved surface having an arc cross-sectional shape having a gap of 15 to 25% of the outer diameter of the cylindrical impeller.

Further, it is preferable that the stabilizer has an arc-shaped cross-section having a radius of curvature of 5 to 23% of the outer diameter of the arc-shaped impeller on the outlet side.

[0010]

Embodiments of the present invention will be described below with reference to the accompanying drawings.

1 and 2, an evaporator 12, a pair of cylindrical impellers 13, and a motor 14 for driving both cylindrical impellers 13 are provided in a casing 11. It is a configuration provided.

The casing 11 includes an upper case 15 fixed to a ceiling surface of an automobile or the like, and a lower case 18 having a suction port 16 and an air outlet 17 formed at substantially opposing positions. The suction port 16 has a plurality of vertically elongated slits 19 arranged in parallel. The outlet 17 is constituted by openings 20 which are separated from each other at two places on the left and right. Each opening 20 is divided in the width direction by a plurality of deflection plates 21. The plurality of deflection plates 21 are connected to each other, rotate around a support shaft (not shown), and change the air blowing direction.

The evaporator 12 is arranged on the suction port 16 side and has a conventionally well-known configuration for cooling the passing air.

The cylindrical impeller 13 has a curved blade 13b between a plurality of disks 13a (some of which are formed in a donut shape other than both ends) arranged at a predetermined interval.
Are arranged side by side along the circumferential direction.

The motor 14 has a rotating shaft 14a at both ends. Each rotating shaft 14a is connected to a rotating shaft 13c of the cylindrical impeller 13 via a joint 22.

As shown in FIG. 2, a rear guide 23 and a stabilizer 24 are formed on the inner surfaces of the upper case 15 and the lower case 18 to form a gap at a predetermined interval along the outer peripheral shape of the cylindrical impeller 13. Each is provided. The rear guider 23 is formed such that the gap between the rear guider 23 and the cylindrical impeller 13 gradually widens toward the outlet 17 side.

On the other hand, the stabilizer 24 is formed so that the value of each part shown in FIG. 2 becomes a value determined by an experiment described later. Here, t1 is the shortest clearance dimension formed on the side of the outlet 17 from the rotation center of the cylindrical impeller 13, a
Is the angle between the horizontal plane and the straight line connecting the shortest gap position and the rotation center of the cylindrical impeller 13; t2 is the shortest gap dimension formed on the suction port 16 side from the rotation center of the cylindrical impeller 13; Is the angle formed by the straight line connecting the shortest gap position and the rotation center of the cylindrical impeller 13 with the vertical plane, and t3 is the cylindrical impeller 13 of the intermediate portion excluding the outlet 17 side and the suction port 16 side. Is the gap size at the position where the distance from the center of rotation is the largest. In the experiment, the outer diameter of the cylindrical impeller 13 was 60 mm, the length was 330 mm, and the rotation speed was 3000 rpm.
(Constant), the ventilation resistance of the evaporator 12 was set to 3 mmAq (when the blowing speed was 1 m / s).

First, for the times t1 and t2, no whistling sound or surging sound is generated, and the air flow rate is 450 m ³ / h.
The range maintained above was determined. However, as for the other values, when t1 and t2 are changed, the values are always excluded from the range in which a whistle sound or a surging sound is generated. Here, an experiment was performed with a set to 40.5 °, b set to 13 °, and t3 set to 12 mm.

The results of the experiment are as shown in the graph of FIG. When an experiment was conducted under the above conditions, the result of plotting the air flow obtained by changing the values of t1 and t2 is a curved surface indicated as “air flow with respect to the values of t1 and t2”. The position of 450 m ³ / h on this curved surface is indicated by a one-dot chain line.

As is clear from the experimental results, no whistling sound or surging sound was generated in the range of 8.5 mm to 14 mm at t1 and in the range of 4.2 mm or more at t2. However, the values of t1 and t2 that do not generate a whistle sound or a surging sound are values that change according to the difference in the outer diameter of the cylindrical impeller 13, and the experiment was performed by changing the outer diameter of the cylindrical impeller 13. As a result of the superposition, it was possible to prevent the generation of whistling sound and surging sound by setting the outer diameter to 14% to 24% and 7% or more, respectively.

In the dimension t1, the air flow rate could be maintained at 450 m ³ / h or more in the above range. However, in the dimension t2, when the air flow rate exceeded the range of 7.8 mm to 9.5 mm, the air flow rate was maintained. I couldn't. Therefore, the dimension t
2 is 4.2 mm or more and 7.8 mm or less, said cylindrical impeller 1
In consideration of the difference in the outer diameter of No. 3, the outer diameter is set to 7% or more and 13% or less of the outer diameter.

Hereinafter, the ranges of a, b, and t3 are determined.
Use the median obtained by successive experiments. The results obtained in this way, as shown in the graphs of FIGS. 4 and 5,
The value of a was 38 to 43 ° and the value of b was 11 to 15 °, and no whistling sound or surging sound was generated. Further, as shown in the graph of FIG. 6, when a value of t3 is 9 to 15 mm and a concave surface is formed to be 15 to 25% of the outer diameter of the cylindrical impeller, generation of whistling sound and surging sound is generated. There was no.

The preferred value in each of the determined ranges is its median value.

The outlet 17 of the stabilizer 24
The cross-sectional arc portion on the side (hereinafter, referred to as a peak 25) is shown in FIG.
As shown in the graph of FIG. 5, the protrusion protrudes toward the ventilation path, has a radius of curvature of 3 to 14 mm, and is formed at 5 to 23% of the outer diameter of the cylindrical impeller 13. Thus, the air blown by the cylindrical impeller 13 collides with the ridge 25 to generate a wind noise (see FIG. 8A; when the radius of curvature is less than 3 mm), It does not disturb the flow and reduce the air volume (see FIG. 8B; the radius of curvature is 14 mm)
Over).

The vehicle air conditioner having the above structure can be used, for example, for a rear seat of a one-box car or the like. That is, the vehicle air conditioner is disposed on the ceiling surface of the vehicle so that air can be blown from the front side of the vehicle to the rear seat side. The evaporator 12 is connected in parallel to the vehicle interior heat exchanger during a cooling cycle including a conventionally known compressor, throttle valve, vehicle interior heat exchanger, and vehicle exterior heat exchanger (not shown). In this case, the in-vehicle air conditioner is provided with a suction port (not shown) for sucking outside air, in addition to the suction port 16 for sucking air from the front side in the vehicle, and can be switched to either one. Is preferred.

Although the vehicle air conditioner has been described as being applied for cooling a rear seat in a vehicle, it is needless to say that the air conditioner may be used for heating or for purifying air.

The outlet 17 of the vehicle air conditioner may be constructed as follows. That is, as shown in FIG. 9, one or both of the rear guider 23 and the air outlet 17 side of the stabilizer 24 are constituted by the deflecting blades 26. According to this, since the direction of the air outlet 17 itself or the direction of the air flow can be changed, it is possible to change the air blowing direction without generating wind noise as in the case where a deflecting blade is provided in the air flow.

[0028]

As is apparent from the above description, according to the vehicle air conditioner of the present invention, not only the positional relationship between the rotation center of the cylindrical impeller and the predetermined position of the stabilizer, but also
Since the gap size is also taken into account, it is possible to add a larger ventilation resistance than before while maintaining an appropriate air flow rate, and to reduce the whistling sound and surging sound generated with the rotation of the cylindrical impeller. It can be reliably prevented, and a good air-conditioning environment can be realized.

Further, at an intermediate portion excluding the blow-out port side and the suction port side, with a radius of curvature smaller than the radius of the cylindrical impeller centered on a position below the rotation center of the cylindrical impeller,
Since a concave curved surface having a circular arc cross-sectional shape having a gap of 15 to 25% of the outer diameter of the cylindrical impeller is formed, an appropriate amount of air can be efficiently obtained.

Further, at the outlet side of the stabilizer,
Since the peak portion having an arc cross-sectional shape having a radius of curvature of 8 to 18% of the outer diameter of the arc-shaped impeller is formed, it is possible to prevent whistling sound and surging sound while maintaining a more appropriate air volume. is there.

[Brief description of the drawings]

FIG. 1 is a rear view (a), a plan view (b), and a front view (c) of a vehicle air conditioner according to the present invention.

FIG. 2 is a sectional view of FIG.

FIG. 3 is a graph showing a relationship between t1, t2 and an air flow rate.

FIG. 4 is a graph showing the relationship between “a” and the air flow rate.

FIG. 5 is a graph showing the relationship between b and the amount of air blow.

FIG. 6 is a graph showing a relationship between t3 and an air flow rate.

FIG. 7 is a graph for determining a radius of curvature of a peak.

FIG. 8 is a cross-sectional view showing a state of air flow due to a difference in a radius of curvature of a peak.

FIG. 9 is a cross-sectional view showing another configuration of the rear guider and the stabilizer.

FIG. 10 is a sectional view of a vehicle air conditioner according to a conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 Casing 13 Cylindrical impeller 16 Suction port 17 Blow-out port 23 Rear guider 24 Stabilizer

Claims (4)

[Claims] 1. A cylindrical impeller is disposed in a casing having a suction port and an air outlet at substantially opposite positions, and is disposed horizontally in a direction orthogonal to a direction connecting the air inlet and the air outlet. In the vehicle air conditioner having a rear guider formed above and a stabilizer formed below, a shortest clearance dimension t1 between the cylindrical impeller on the outlet side and the stabilizer, and a rotation center of the cylindrical impeller Angle between the horizontal plane and a straight line connecting the shortest gap position on the outlet side of the stabilizer
A shortest gap dimension t2 between the cylindrical impeller on the suction port side and the stabilizer; and a horizontal plane and a straight line connecting the rotation center of the cylindrical impeller and the shortest gap position on the suction port side of the stabilizer. Angle b
And a value capable of preventing generation of whistle sound and surging sound. 2. The size t1 is 14% or more and 24% or less of the outer diameter of the cylindrical impeller, the angle a is 38 ° or more and 43 ° or less, and the size t2 is a cylindrical impeller. 7% or more of the outer diameter of
The vehicle air conditioner according to claim 1, wherein the angle b is 11 ° or more and 15 ° or less. 3. The stabilizer has a radius of curvature smaller than the radius of the cylindrical impeller at an intermediate portion except for the outlet side and the inlet side, centered on a position below the rotation center of the cylindrical impeller. The vehicle air conditioner according to claim 1, further comprising a concave curved surface having an arc cross-sectional shape having a gap of 15 to 25% of an outer diameter of the cylindrical impeller. 4. The stabilizer according to claim 1, wherein the stabilizer has an arc-shaped cross-section having a radius of curvature of 5 to 23% of an outer diameter of the arc-shaped impeller on an outlet side. Or the air conditioner for vehicles according to 3.