JP2001294032A - Air conditioner for vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an air conditioner for a vehicle capable of reducing noises emitted in the vehicle within a restricted range of a mounting space in the vehicle. SOLUTION: Plural plane parts 52a almost parallel to an inlet surface 50a of a duct 41 as an inlet part to a bent part 50 are formed in steps on an inner wall surface 52A of an outside wall 52 side of the bent part 50 of the duct 41 introducing blast air discharged from a discharge port 37 of an air conditioning case 20 to an outlet port in the vehicle. Thus, noise intruding from the air conditioning case 20 to the duct 41 is reflected to an inlet direction of the bent part 50 by the plural plane parts 52a and interferes with incident noise and declines.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle air conditioner in which measures are taken to reduce blast noise.

[0002]

2. Description of the Related Art Conventionally, as a general air conditioner for a vehicle, for example, a heater core as a hot water type heat exchanger for heating, which has an air intake port for indoor or outdoor air and a discharge port for conditioned air, is provided. An air-conditioning case containing an evaporator as a cooling heat exchanger, a blower having a centrifugal fan for allowing air to flow into the air-conditioning case from an intake port and sending out conditioned air from a discharge port, and An air conditioner is known which comprises a duct for guiding conditioned air into a vehicle cabin.

[0003] As a duct for guiding conditioned air,
As shown in FIG. 5, in order to avoid the mounting space due to the arrangement of the structural parts and other mounting parts constituting the vehicle and avoid this, a smooth R-shape is required while securing the necessary ventilation effective area. A duct having a bent portion formed by a wall is known.

[0004]

However, in the above air conditioner, the noise generated by the fan enters the duct from the discharge port of the air conditioning case, and then is radiated into the passenger compartment from the air outlet, and the noise in the passenger compartment is reduced. It is a cause that hinders.

[0005] As shown in FIG. 5, when the noise that has entered the duct 81 reaches the bent portion 90 constituted by the R-shaped wall, a part of the inner wall surface of the bent portion 90 on the outer wall 92 side is used. Most of the noise is reflected by the inner wall surface on the side of the R-shaped outer wall 92, is reflected by the inner wall surface on the side of the R-shaped outer wall 92, travels downstream in the duct (air outlet side), and travels from the air outlet to the vehicle. This is to reach the room.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a vehicle air conditioner capable of reducing noise radiated into a vehicle compartment within a limited range of a vehicle mounting space.

[0007]

In order to achieve the above object, according to the first aspect of the present invention, blast air discharged from a discharge port (37) of an air-conditioning case (20) is supplied to an air outlet (31) in a vehicle compartment. ), The inner wall surface (52A) on the outer wall (52) side of the bent portion (50) of the duct (41) is bent.
It is characterized in that the structure is such that noise entering from the upstream side of the blown air flow in 0) is hardly reflected to the downstream side.

According to this, the noise that has entered the duct (41) from the air-conditioning case (20) is transferred downstream by the inner wall surface (52A) on the outer wall (52) side of the bent portion (50) of the duct (41). Side, that is, other than the side of the outlet (31). Accordingly, noise radiated from the air outlet (31) into the vehicle interior is reduced, and quietness in the vehicle interior is maintained. In this manner, the noise radiated into the vehicle cabin can be reduced by the duct (41) having the bent portion (50) disposed within the restricted range of the vehicle mounting space.

According to the second aspect of the present invention, the duct (41) serving as an entrance to the bent portion (50) is provided on the inner wall surface (52A) on the outer wall (52) side of the bent portion (50). A plurality of flat portions (52a) substantially parallel to the entrance surface (50a) are provided in a stepwise manner.

According to this, the noise that has entered the duct (41) from the air conditioning case (20) is caused by the plurality of flat portions (52a) formed on the inner wall surface (52A) of the bent portion (50). 50) is reflected on the entrance surface (50a) side,
Interferes with incoming noise and attenuates. Therefore, the noise radiated from the air outlet (31) into the vehicle interior can be reliably reduced, and the quietness in the vehicle interior is improved. In this way, the bent portion (50) arranged within the restricted range of the vehicle mounting space
The noise radiated into the vehicle interior can be reduced by the duct (41) having the above.

According to the third aspect of the present invention, the inner wall surface (52A) of the bent portion (50) on the outer wall (52) side has:
It is characterized in that a plurality of plane portions (52a) substantially orthogonal to the direction of the flow of the blown air to the bent portion (50) are formed in a stepwise manner.

According to this, the noise that has entered the duct (41) from the air conditioning case (20) is reduced by the plurality of flat portions (52a) formed on the inner wall surface (52A) of the bent portion (50). 50) is reflected on the upstream side of the flow of the blown air, interferes with the incoming noise, and attenuates. Therefore, the noise radiated from the air outlet (31) into the vehicle interior can be reliably reduced, and the quietness in the vehicle interior is improved. In this manner, the bent portion (5) disposed within the restricted range of the vehicle mounting space.
With the duct (41) having (0), the noise radiated into the vehicle interior can be reduced.

The inner wall surface (52A) on the side of the outer wall (52) of the bent portion (50) in which a plurality of flat portions (52a) are formed in a step shape is specifically the invention according to claim 4. As shown in the above, the duct (41) having a rectangular longitudinal section can be formed on one side of the square.

The reference numerals in parentheses attached to the respective means indicate the correspondence with specific means described in the embodiments described later.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below with reference to the drawings.

(Embodiment) FIG. 1 is a schematic structural view schematically showing a structure of an automotive air conditioner to which the present invention is applied.

As shown in FIG. 1, a blower motor 1 for generating an air flow in the air conditioner case 20 is provided in the case 20.
1, a blower 19 which is a fan driven by the fan 1 is provided. Here, the blower motor 11 and the blower 19 constitute a blower. An evaporator 12 is disposed downstream of the blower 19 so as to close the ventilation duct 20, and the evaporator 12 cools the airflow blown out by the blower 19.

A heater core 13 is disposed downstream of the evaporator 12 so as to close the air-conditioning case 20 by about half. The heater core 13 reheats the cool air passing through the evaporator 12. An air mix damper 21 that switches the ratio of air passing through the heater core 13 to adjust the temperature of the air blown into the vehicle interior is provided upstream of the heater core 13.

At the upstream side of the blower 19, there are provided an inside air suction port 4 for taking in inside air and an outside air suction port 5 for taking in outside air, and an inside / outside air switching damper 6 for switching a ratio of taking in inside air and outside air is provided. Have been.

At the most downstream of the air-conditioning case 20, a defroster discharge port 36 for sending out air whose temperature is adjusted by the evaporator 12 and the heater core 13 to a defroster outlet 30 for blowing toward a windshield, and a face for blowing toward the upper body of the occupant. A face discharge port 37 for discharging to the outlet 31 and a foot discharge port 38 for discharging to the foot outlet 32 for blowing toward the feet of the occupant are provided. The amount of air sent from each of these discharge ports is adjusted by a defroster damper 33, a face damper 34, and a foot damper 35, respectively.

The temperature-controlled air sent from each outlet to each outlet is guided by a defroster duct 40, a face duct 41 and a foot duct 42, respectively. Hereinafter, a specific configuration of the face duct 41 will be described.

The face duct 41 is formed into a hollow shape by blow molding a resin such as polypropylene, as shown in FIG. The face duct 41 is open at both ends, and the upstream opening 41 a of the air flow is connected via a packing 44 to a position substantially coincident with the face discharge port 37 provided in the air conditioning case 20.

The downstream opening 41b of the air flow is fitted with the end of the face outlet register 45 constituting the face outlet 31, and is fixed by a claw-shaped snap fit (not shown) so as not to fall off. .

The face duct 41 has a rectangular vertical section (in this example, rectangular), and includes a bent portion 50 that changes the direction of air flow and a straight portion 51.
In this example, the entrance surface 50a of the bent portion 50 is on the same surface as the upstream opening 41a. The inner side wall 53 on the inner peripheral side of the bent portion 50 has an R
It is a shape wall. On the other hand, the inner wall surface 52 </ b> A of the outer wall 52, which is the outer peripheral side of the bent portion 50, has a vertical section corresponding to one side of a rectangular shape (rectangle), and a plurality of parallel surfaces substantially parallel to the entrance surface 50 a of the face duct 41. Surface 52a and entrance surface 50a
A plurality of vertical surfaces 52b which are substantially perpendicular to each other are formed with a stepped wall alternately arranged.

The vertical cross section of the face duct 41 may be a circle or an ellipse instead of a square.
If the inner wall surface 52A on the side is stepped as described above, the same operation and effect can be obtained.

Next, in the above configuration, the face duct 4
The operation in the case where noise has entered the interior 1 will be described.

The noise generated by the blower 19 enters the face duct 41 from the face discharge port 37 of the air conditioning case 20. Part of the noise that has entered the face duct 41 is transmitted toward the downstream opening 41 b by the blast air flowing through the face duct 41, but most of the noise is the entrance surface of the bent portion 50 of the face duct 41. Go straight in the direction perpendicular to 50a.

Then, the noise collides substantially perpendicularly with a parallel surface 52a formed on the inner wall surface 52A on the outer wall 52 side. A part of the colliding noise is absorbed by the parallel surface 52a and converted into heat energy and dissipated, but a large part of the colliding noise is reflected by the parallel surface 52a and proceeds toward the face discharge port 37. The noise traveling toward the face discharge port 37 interferes with the noise that enters the face duct 41 from the face discharge port 37 and is attenuated.

Accordingly, the noise radiated from the face outlet 31 into the vehicle interior is reduced as compared with the conventional air conditioner, and the quietness in the vehicle interior is improved. Further, since the inner wall surface 52A on the outer wall 52 side of the bent portion 50 of the face duct 41 is formed in a step shape, it does not interfere with the vehicle structural component 60.

As described above, the duct having the bent portion 50 disposed within the restricted range of the vehicle mounting space can reduce the noise radiated into the vehicle interior.

Next, FIGS. 3 and 4 show a method of confirming the noise reduction effect of the face duct 41 of the present embodiment performed by the present inventors and the results of the confirmation.

As shown in FIG. 3, an upstream opening 41 a of a face duct 41 having a rectangular cross section is connected to a face discharge port 37 provided in the air conditioning case 20, and 50 mm upstream from the face discharge port 37. Separated air conditioning case 20
Inside, the speaker 70 was arranged. Further, a microphone 71 is provided at the center of the upstream opening 41a of the face duct 41.
At an angle of 45 ° outward from the center of the downstream opening 41b.
The microphone 72 was arranged at a position separated by 000 mm.

On the inner wall surface 52A on the outer wall 52 side of the bent portion 50, a stepped wall composed of a parallel surface 52a parallel to the entrance surface 50a of the face duct 41 and a vertical surface 52b is provided.

In this configuration, the upstream side opening 41a of the face duct 41 is located at one end from the upstream side of the air conditioning case 20.
While blowing in an air volume of 150 cubic meters per hour, a 70 dB (A) pink noise oscillating from the speaker 70 was generated from the speaker 70. This pink noise is obtained by performing frequency correction on pink noise, which is noise of a continuous spectrum that is constant irrespective of frequency, based on an equality curve.

Then, for pink noise from 20 Hz to 10 kHz, the total sound pressure energy Lpin is measured by the microphone 71 and the total sound pressure energy Lpout is measured by the microphone 72 to reduce the sound volume Lpin−Lpo.
ut was calculated.

The case where the face duct 41 of this embodiment is connected to the face discharge port 37 and the case where the conventional face duct 81 having a bent portion whose inner wall surface on the outer wall side is formed in an R shape are connected. FIG. 4 shows comparison data of the sound reduction. The duct of the present embodiment is better than the conventional duct,
A large sound reduction of about 7 dB was obtained.

From these results, it can be seen that the duct shape according to the present invention is extremely effective in reducing the noise radiated into the passenger compartment.

(Other Embodiments) In the above embodiment, the structure is such that the noise that has entered the inner wall surface 52A on the outer wall 52 side of the bent portion 50 from the upstream side of the blown air is not reflected downstream, Although a plurality of flat portions substantially parallel to the entrance surface 50a are provided, any other structure may be used as long as it does not reflect the intruding noise to the downstream side.

In the above embodiment, the face duct 41 has the inlet surface 50a of the bent portion 50 on the same surface as the upstream opening portion 41a. The inlet surface 50a may be a boundary surface between the straight portion and the bent portion 50.

In the above embodiment, the face duct 41 has one bent portion 50.
A duct having two or more bent portions may be used.

In the above embodiment, the face duct 41 is integrally formed by blow molding. However, the face duct 41 may be formed by dividing into two or more parts and combining them.

In the above embodiment, the inner surface 52A of the bent portion 41 of the face duct 41 on the outer wall 52 side is used.
Is formed in a step shape, but it goes without saying that a similar effect can be obtained by applying to a duct having another bent portion.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram schematically showing a configuration of an automotive air conditioner according to an embodiment of the present invention.

FIG. 2 is a schematic cross-sectional view of a main part of a face duct portion of the automotive air conditioner in the embodiment.

FIG. 3 is a schematic configuration diagram showing a method for confirming a noise reduction effect of the face duct of the embodiment.

FIG. 4 is a graph of sound volume reduction showing a result of confirming a noise reduction effect of the face duct of the embodiment.

FIG. 5 is a schematic cross-sectional view of a main part of a face duct portion of a vehicle air conditioner according to the related art.

[Explanation of symbols]

 Reference Signs List 19 blower 20 air conditioning case 31 face outlet 34 face damper 37 face outlet 41 face duct 41a upstream opening 41b downstream opening 45 face blowing register 50 bent portion 50a inlet surface 52 outer wall 52A inner wall surface 52a parallel surface 52b vertical Surface 60 Vehicle structural parts

Claims (4)

[Claims] An air-conditioning case (20) having a suction port (4, 5) at one end and a discharge port (36, 37, 38) at the other end, and blowing air into the air-conditioning case (20). A blower (11, 19) having a fan (19) for generating a flow of air; and a bent portion (50) according to the shape of the vehicle, wherein the blown air discharged from the discharge port (37) is supplied to a vehicle interior. And a duct (41) leading to the outlet (31) of the vehicle, wherein the bent portion (50) has an outer wall (52) and an inner wall (53) of the duct (41), The outer wall (52)
An air conditioner for a vehicle, characterized in that the inner wall surface (52A) on the side has a structure in which noise entering the bent portion (50) from the upstream side of the flow of the blown air is hardly reflected to the downstream side. 2. A plurality of flat portions (52a) substantially parallel to an inlet surface (50a) of a duct (41) serving as an inlet portion to the bent portion (50) are provided on the inner wall surface (52A). The vehicle air conditioner according to claim 1, wherein the air conditioner is formed in a shape. 3. A plurality of flat portions (52a) which are substantially perpendicular to the direction of the flow of the blast air to the bent portion (50) are formed on the inner wall surface (52A) in a stepwise manner. The vehicle air conditioner according to claim 1, wherein: 4. The vehicle according to claim 2, wherein a longitudinal section of the duct (41) is rectangular, and the inner wall surface (52A) is formed as a rectangular piece. Air conditioner.