1. Technical Field
The present invention relates to a vehicle air-conditioning apparatus, and to a vehicle air-conditioning apparatus in which measures to reduce a noise in an intake unit are implemented.
2. Description of the Invention
In a vehicle air-conditioning apparatus, a noise generated in a blower passes through an air conditioning case, and enters a vehicle interior from a blowout port for blown air, and hence a problem of impairment of silence in the vehicle interior may arise. In order to solve this problem, a technology of providing an air-conditioning casing with a sound absorbing material is proposed (For example, see Patent Literature 1). A technology of providing an air-intake duct which constitutes part of a seat air-conditioning system with a reflecting wall configured to reflect a noise entering the duct from the blower is proposed (For example, see Patent Literature 2). A technology of forming an inner wall surface of the duct configured to introduce blown air into a blowout port in the vehicle interior in a staircase shape is proposed (For example, see Patent Literature 3).
Although it is not a technology to reduce a noise generated in a blower, a technology in which a surface of an air-conditioning case that opposes a core surface of an evaporator of an air conditioning case is formed into a staircase shape along an air inflow direction is proposed as a technology of reducing a noise caused by a separation flow that is generated in a diffuser unit in which an air flow channel is enlarged (For example, See Patent Literature 4).
Patent Literature 1: JP-A-2000-85339
Patent Literature 2: JP-A-2006-130989
Patent Literature 3: JP-A-2001-294032
Patent Literature 4: JP-A-2009-61863
However, the technology using the sound absorbing material as described in Patent Literature 1 has a problem of an increase in cost. The noise generated in the blower enters the vehicle interior not only from the blowout port of the blown air, but also from an inside air introduction port of the intake unit arranged on an upstream side of the blown air with respect to the blower. However, measures to reduce a noise in the intake unit are not implemented in Patent Literature 2, Patent Literature 3, and Patent Literature 4.
It is an object of the invention to provide a vehicle air-conditioning apparatus, in which measures to reduce a noise in an intake unit are implemented.
The invention provides a vehicle air-conditioning apparatus of the invention including: an outside air introduction port configured to take air outside a vehicle; an inside air introduction port configured to take air in a vehicle interior; an intake unit having an intake passage in which air taken from one or both of the outside air introduction port and the inside air introduction port flows, and an outlet port from which the taken air flows out; a blast unit having an intake port for taking air flowed out from the outlet port and a blower for sucking air from the intake port and blowing the air to downstream; and a temperature regulating unit configured to regulate the temperature of blown air blown by the blower, wherein a wall that forms the intake passage includes a cylindrical portion having a downstream end at the outlet port, and part of an inner wall surface of the cylindrical portion is a reflecting surface configured to reflect a noise of the blower entering the intake passage toward the outlet port.
According to the vehicle air-conditioning apparatus of the invention, preferably, the reflecting surface opposes a surface that is formed by the intake port. A reflected sound is concentrated to a noise generating source (blower) further effectively to further reduce the noise.
According to the vehicle air-conditioning apparatus of the invention, preferably, the reflecting surface is provided on a lower portion of an inner wall surface of the cylindrical portion, and a surface connected to an upper end of the reflecting surface and a surface connected to a lower end of the reflecting surface form downward inclined surfaces directed toward the outlet port. Accumulation of water such as rain water in the intake passage may be prevented.
According to the vehicle air-conditioning apparatus of the invention, preferably, thickness of a portion of wall where the reflecting surface is provided is larger than thickness of a portion of wall where the surface connected to the reflecting surface is provided. The portion of the wall where the surface connected to the reflecting surface is provided is not formed to have a thick shape, which contributes to a reduction of thickness of a case. In addition, the portion of the wall where the reflecting surface is provided contributes to reduce a transmissivity of a sonic wave to improve a reflectivity thereof. Consequently, the noise may further be reduced.
According to the vehicle air-conditioning apparatus of the invention, preferably, a reinforcing rib is provided on an outer wall surface of the portion of the wall where the reflecting surface is provided. By increasing rigidity of the portion of the wall where the reflecting surface is provided, the transmissivity of the sonic wave can be reduced to improve the reflectivity and hence the noise can further be reduced.
According to the vehicle air-conditioning apparatus of the invention, preferably, the reflecting surface is a depressed curved surface. A reflected sound is concentrated to a noise generating source (blower) further effectively to further reduce the noise.
According to the vehicle air-conditioning apparatus of the invention, preferably, the reflecting surface includes a plurality of areas having different curvatures. An attenuation effect for sounds in a larger frequency range can be obtained.
According to the vehicle air-conditioning apparatus of the invention, preferably, a plurality of reflecting surfaces and the surfaces connected to the reflecting surfaces are arranged alternately in a staircase manner and the reflecting surfaces have nonsimilar shapes with respect to each other. An attenuation effect for sounds in a larger frequency range can be obtained.
According to the vehicle air-conditioning apparatus of the invention, preferably, the plurality of reflecting surfaces are depressed curved surfaces, and are arranged in descending order in the maximum curvature of a lateral cross section in a width direction from the outlet port side of the reflective surface. An attenuation effect for sounds in a larger frequency range can be obtained.
The invention provides a vehicle air-conditioning apparatus in which measures to reduce a noise in an intake unit are implemented.
Referring now to the attached drawings, a mode of the invention will be described below. Embodiments described below are an example of the invention, and the invention is not limited to the following embodiments. In the specification and the drawings, components having identical reference signs are the same components. Various modifications may be made for achieving advantageous effects of the invention.
The vehicle air-conditioning apparatus 1 includes the intake unit 10, the blast unit 20, the temperature regulating unit 30, and an air distributing portion 40, and is formed integrally with a case 2 as illustrated in
The intake unit 10 includes the outside air introduction port 11 and the inside air introduction port 12 opened through the case 2 and an inside and outside air switching door 15 arranged in the case 2 as illustrated in
The blast unit 20 includes the blower 22 arranged in the interior thereof as illustrated in
The temperature regulating unit 30 includes a cooling heat exchanger 31 arranged in the interior thereof as illustrated in
The air distributing portion 40 includes a defrost opening 41, a ventilation opening 42, and a foot opening 43 as illustrated in
The cylindrical portion 50 is part of a wall forming the intake passage 13, and is a duct having a downstream end at the outlet port 14 as illustrated in
The reflecting surfaces 51 are portions of the inner wall surfaces of the cylindrical portion 50 opposing a surface F1 formed by the outlet port 14 as illustrated in
The reflecting surfaces 51 may be formed by projecting and depressing the wall itself of the cylindrical portion 50 to have concavities and convexities or may be provided by increasing the thickness of the wall of the cylindrical portion 50 to form concavities and convexities (not illustrated) as illustrated in
According to the vehicle air-conditioning apparatus 1 of the embodiment, preferably, the reflecting surfaces 51 are provided on a lower part of an inner wall surface of the cylindrical portion 50, and surfaces 52 connected to upper ends 51u and lower ends 51b of the reflecting surfaces 51 form downward inclined surfaces directed toward the outlet port 14. The downward inclined surface means a surface which is lowered in height with respect to the horizontal plane as it goes toward the outlet port 14. Accumulation of water such as rain water in the intake passage 13 may be prevented. Preferably, a water passing portion 16 is provided at a boundary between the intake unit 10 and the blast unit 20 to blow out water flowing along the surfaces 52 connected to the reflecting surfaces 51 toward downstream by the blower 22 or discharge to the outside of the case 2 as needed. The water passing portion 16 is, for example, a notch provided on the bell mouth 23, or a hole provided on a bottom surface of the case 2.
The reflecting surfaces 51 preferably have at an elongated shape having a height shorter than a width. The height of the reflecting surfaces 51 here is a length in the vertical direction of a vehicle when the reflecting surfaces 51 are provided on the lower part of the inner wall surface of the cylindrical portion 50 as illustrated in
The reinforcing ribs 53 and 54 may be molded integrally with the cylindrical portion 50 or may be provided separately therefrom. When forming the reinforcing ribs 53 and 54 separately from the cylindrical portion 50, the reinforcing ribs 53 and 54 may be formed of the same material as that of the cylindrical portion 50 or may be formed of a different material from that of the cylindrical portion 50. The cylindrical portion 50 is manufactured by injection molding and the reinforcing ribs 53 and 54 are molded integrally with the cylindrical portion 50, so that the reinforcing ribs may be formed into a cylindrical portion without adding a step.
In this embodiment, the thickness of the portion of the wall where the reflecting surfaces 51 are provided may be set to a thickness larger than that of the portion of the wall where the surfaces 52 connected to the reflecting surfaces 51 are provided and the reinforcing ribs 53 and 54 may be provided on the outer wall surface 61 of the portions of the wall where the reflecting surfaces 51 are provided.
Preferably, the reflecting surfaces 51 include a plurality of areas having different curvatures when the reflecting surfaces 51 are curved surfaces. An attenuation effect for sounds in a larger frequency range can be obtained. A mode in which the plurality of areas having different curvatures is, for example, a mode in which areas having the smallest curvature are arranged at widthwise center portions of the reflecting surfaces 51 and areas having a larger curvature than that of the center portions are arranged on both side portions in the width direction or a mode in which areas having the largest curvature are arranged at the widthwise center portions of the reflecting surfaces 51 and areas having a curvature smaller than that of the widthwise center portions are arranged on both end portions in the width direction. In this embodiment, the mode in which the plurality of areas have different curvatures includes a mode in which the curvature is continuously changed as the mode in which the lateral cross-sectional shape in the width direction of the reflecting surfaces 51 is an elliptical arc shape.
Even though the reflecting surfaces 51 are curved surfaces, in the same manner as a case where the reflecting surfaces 51 are flat surfaces, the thickness of the portions of the wall where the reflecting surfaces 51 are provided may be set to be larger than the thickness of portions of the wall where the surfaces 52 connected to the reflecting surfaces 51 are provided as illustrated in
According to the vehicle air-conditioning apparatus 1 of the embodiment, preferably, a plurality of reflecting surfaces 51 and the surfaces 52 connected to the reflecting surfaces 51 are arranged alternately in a staircase manner and the reflecting surfaces 51 have nonsimilar shapes with respect to each other as illustrated in
Although the mode in which the reflecting surfaces 51 are provided on the inner wall surface on the lower portion of the inner wall surface of the cylindrical portion 50 has been described thus far, the invention is not limited thereto, and the reflecting surfaces 51 may be provided on an upper portion of the inner wall surface of the cylindrical portion 50, for example. The reflecting surfaces 51 may be provided in a plurality of directions on the inner wall surface of the cylindrical portion 50. The mode in which the reflecting surfaces 51 are provided in a plurality of directions on the inner wall surface of the cylindrical portion 50 is, for example, a mode of providing both on the lower portion of the inner wall surface and on the upper portion of the inner wall surface of the cylindrical portion 50.
1: vehicle air-conditioning apparatus
2: case
10: intake unit
11: outside air introduction port
12: inside air introduction port
13: intake passage
14: outlet port
15: inside and outside air switching door
16: water passing portion
20: blast unit
21: intake port
22: blower
22
a: centrifugal multiblade fan
22
b: motor
23: bell mouth
30: temperature regulating unit
31: cooling heat exchanger
32: heating heat exchanger
33: air mixing door
40: air distributing portion
41: defrost opening
42: ventilation opening
43: foot opening
44, 45, 46: mode door
50: cylindrical portion
51: reflecting surface
51
u: upper end of the reflecting surface
51
b: lower end of the reflecting surface
52: surface connected to the reflecting surfaces
53: reinforcing rib
54: reinforcing rib
55: bent portion
61: outer wall surface
F1: surface formed by outlet port
F2: surface formed by intake port
Number | Date | Country | Kind |
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2014-233502 | Nov 2014 | JP | national |