JPH0825383B2 - Automotive air conditioners - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to reduction of aerodynamic noise generated in a ventilation path in an automobile air conditioner.

[Conventional technology]

Conventionally, when mounting an air conditioner on an automobile, part of the air passage of this automobile air conditioner is curved or the area of the air passage is suddenly expanded or reduced due to restrictions on the installation space or layout. That is an unavoidable fact. As described above, when the ventilation passage is curved and the ventilation passage area is suddenly expanded or contracted, the wind velocity distribution is biased in this portion, and as a result, noise generated from the ventilation passage is increased.

By the way, in an automobile air conditioner, a downstream end of the ventilation passage is arranged at a predetermined portion in a vehicle compartment, and from this end, heat is directly exchanged with an occupant present in a narrow space such as the vehicle compartment. Because it blows out air,
When the noise generated from the ventilation passage becomes large as described above,
This noise is directly transmitted from the downstream end of the ventilation passage to the passenger in the vehicle compartment, which gives the passenger an uncomfortable feeling.

Therefore, in order to eliminate the above-mentioned deviation of the wind speed distribution and reduce the noise, as in the invention described in FIG. 5 of Japanese Utility Model Application Laid-Open No. 61-189120, air is distributed to the part where the wind speed distribution is uneven. There is a device in which a rectifying member (specifically, a perforated plate) is provided, and this air rectifying member makes the wind velocity distribution uniform, thereby reducing the amount of noise generated from the ventilation passage.

[Problems to be Solved by the Invention]

However, in the invention shown in FIG. 5, the air rectifying member is composed of a perforated plate. Therefore, if the invention shown in FIG. Noise (eg, wind noise) when passing through becomes large. Therefore, even if the air rectifying member can make the deviation of the wind speed distribution uniform, the noise from the air rectifying member itself is directly transmitted to the passenger in the passenger compartment.

Therefore, in view of the above problems, the present invention provides an air rectifying member in a portion where the wind speed distribution in the vehicle air conditioner is biased to uniformize the wind speed distribution, while reducing the noise generated from the air rectifying member itself, The purpose is to prevent this noise from being directly transmitted to passengers in the passenger compartment.

[Means for solving the problem]

In order to achieve the above object, in the invention according to claim 1, the air-conditioning case is provided with at least an air-blowing means for generating an air flow and a heat-exchange means for exchanging heat with the air blown by the air-blowing means. The air that has been heat-exchanged by the heat exchange means is configured to be blown into the vehicle interior through an air conditioning duct connected to the downstream side of the air conditioning case, and the downstream end of the air conditioning duct is a predetermined portion in the vehicle interior. Is provided in the vehicle compartment, the upstream end of the air conditioning duct and the air conditioning case,
In a vehicle air conditioner connected in such a manner that the wind velocity distribution of the air flowing into the air conditioning duct is biased to such an extent that noise is generated in the air conditioning duct, a plurality of filaments are provided near the upstream end of the air conditioning duct. An air conditioner for a vehicle, characterized in that the members are formed in a mesh shape and provided with an air rectifying member that reduces the noise by rectifying the inflowing air.

In the invention according to claim 2, in the vehicle air conditioner according to claim 1, the air conditioning duct has a defroster duct provided at a position where the downstream end faces a window glass in a vehicle compartment, and It is characterized in that the downstream end is at least one of upper ducts provided in an upper portion of the vehicle compartment.

The form in which the wind speed distribution of the inflowing air into the air conditioning duct is biased to the extent that noise is generated in the air conditioning duct is a form in which the air passage extending from the air conditioning case to the air conditioning duct is curved. Alternatively, the area of the ventilation passage is abruptly expanded or contracted.

[Action]

According to the first or second aspect of the present invention, when the airflow in the air conditioning case generated by the air blowing means flows into the upstream end of the air conditioning duct, the inflowing air tends to have an uneven wind speed distribution, As a result, it tries to generate noise in the air conditioning duct.

However, in the present invention, an air rectifying member configured by meshing a plurality of thread members is provided at the upstream end of the air conditioning duct. According to this, the air immediately after passing through the air rectifying member is peeled off along the cross section of the filamentous member, so that the peeling region formed in the region immediately downstream of the filamentous member in the air is extremely small. As described above, since the air immediately after passing through the air rectifying member hardly causes turbulent flow, the noise generated from the air rectifying member itself becomes small.

Further, since the air rectifying member itself is provided in the vicinity of the upstream side end portion, the noise from the air rectifying member itself is insulated and attenuated by the air conditioning duct on the downstream side.

〔The invention's effect〕

As described above, in the present invention, by providing the air rectifying member, it is possible to uniformize the wind speed distribution and reduce noise, and by configuring the air rectifying member with a plurality of thread-like members in a mesh shape, Noise can be reduced, and by providing the air rectifying member at the upstream end, the noise from the air rectifying member itself can be insulated and attenuated by the air conditioning duct, thereby producing the noise from the air rectifying member. Can be prevented from being directly transmitted to passengers in the passenger compartment.

Therefore, when the air heat-exchanged by the heat exchange means is blown toward the passenger in the passenger compartment through the air conditioning duct, noise at that time is not directly transmitted to the passenger, so that the passenger is comfortably air-conditioned. be able to.

〔Example〕

 Hereinafter, a first embodiment of the present invention will be described with reference to the drawings.

As shown in FIG. 1, the inside / outside air switching box 1 has an outside air inlet 1a.
And the air circulation port 1b is open.

Further, the inside / outside air switching box 1 is provided with an inside / outside air switching damper 2, which switches between the inside air circulation and the outside air introduction.

A blower 3 is connected to the downstream side of the inside / outside air switching box 1, and a centrifugal fan 4 is provided in the blower 3.
In this embodiment, the centrifugal fan 4 constitutes the blowing means.

A heater case 5 (including a cooler duct, a connection duct, etc.) forming a part of a ventilation path is connected to the downstream side of the blower 3. Inside the heater case 5, an evaporator 6 that removes heat from the air, a heater core 7 that heats the air, and an air mix damper that adjusts the amount of air passing through the heater core 7 to adjust the temperature of the air blown into the passenger compartment. 7a is provided. In this embodiment, the evaporator 6 and the heater core 7 constitute heat exchange means.

Further, one end (an upstream end in the present invention) is opened in the heater case 5 on the downstream side of the heater case 5, and the other end (a downstream end in the present invention) is opened toward the front window side. A defroster duct 8 having one end open to the inside of the heater case 5 and the other end having an opening to the front of the front panel.
The heater ducts 10, which are open inside and the other end is open near the lower part of the vehicle compartment, are connected to each. Each duct is provided with a defroster damper 11, a ventilation damper 12, and a heat damper 13 for switching communication or blocking of the ventilation path.

In this embodiment, the inside / outside air switching box 1, the case around the blower 3, and the heater case 5 constitute an air conditioning case, and the defroster duct 8 constitutes an air conditioning duct.

Further, in this embodiment, a wire mesh 14 which is an air rectifying member is provided at the curved portion near the defroster duct inlet 8a of the defroster duct 8 or the sudden expansion / contraction portion of the ventilation passage.

As shown in FIG. 2, a wire net 14 made of a material such as iron or stainless steel is connected and fixed to the defroster duct 8 by screws or the like near the defroster duct inlet 8a of the defroster duct 8. The entire area of this wire mesh does not serve as a ventilation path, and some wind is blocked by the wire mesh itself. Therefore, when the area of the wire netting 14 is set to 1, the ventilation degree of the wire netting may be ensured at a ratio of the actual opening area of the wire netting that flows without blocking the wind of about 0.1 to 0.9. Further, regarding the number of holes formed in the wire net 14, if one side is a 25 mm square, and if it is a fine hole such that about 10 × 10 to 60 × 60 holes are formed in this square, good. Furthermore, the wire diameter of the wire mesh 14 is about 0.15 to 0.5 m.
About m is desirable.

The number of holes, the wire diameter, the shapes of the wires and the holes of the wire netting 14 are arbitrarily selected according to the usage condition.

The air sucked by the centrifugal fan 4 passes through the evaporator 6 and the like and is guided to each duct.

Air is introduced into the defroster duct 8 by opening the defroster damper 11. The ventilation passage area of the duct opening 8b of the defroster duct 8 on the heater case 5 side is smaller than the ventilation passage area of the heater case 5, and the ventilation passage of the air flowing in the defroster duct 8 flows in the heater case 5. Since the air is branched from the ventilation path at an angle, the airflow is disturbed, and the air guided to the defroster duct 8 does not have a uniform wind speed distribution. At this time, when air passes through the wire net 14, the dynamic pressure component of high wind speed generated in the high wind speed region is reduced by colliding with the line portion (the thread member in the present invention) of the wire net 14. By reducing this dynamic pressure component, the air passing through the wire netting 14 is rectified and the wind velocity distribution becomes uniform.

Further, in the present embodiment, when the heat exchange air passes through the wire netting 14, the heat exchange air peels off along the cross-sectional shape of the wire netting 14. The area becomes extremely small. Therefore, the air immediately after passing through the wire net 14 has almost no turbulent flow.
The amount of noise generated from itself is reduced.

Therefore, vibration of air particles and collision between air are reduced. Then, the local high wind velocity does not collide strongly with the instrumental panel 8c, and the noise is reduced.

Also, with the air that strongly collided with the instrumental 8c,
Furthermore, the blowing air does not collide strongly, and noise is reduced.

FIG. 3 shows the wind speed distribution when the wire net 14 is provided near the inlet 8a of the defroster duct.

The maximum wind speed without wire mesh 14 was about 12 m / S (Fig. 13), but the maximum wind speed with wire mesh 14 was about 12 m / S.
The wind speed is 6m / S, which is about half the wind speed compared to the case without wire mesh 14. In addition, the width of the wind speed distribution was about 1 to 12 m / S (Fig. 13) without the wire mesh 14, but it was reduced to about 2 to 6 m / S by installing the wire mesh 14, and the wind speed distribution was uniform. Be converted.

The influence of the installation of the wire nets 14 on the air flow is basically the above-mentioned substantial opening area of the wire nets 14 (1 to 9
However, by increasing the total area of the wire mesh, the effect on air volume can be reduced.

In other words, the part that most affects the air volume is the duct opening.
It is an opening area of 8b, and by making this opening area and the substantial total opening area of the wire netting 14 equivalent, it is possible to suppress the reduction of the air volume.

According to the experiments conducted by the present inventors, the wire mesh shape is set to the downstream side as shown in FIG. 6 so that the substantial opening area of the wire mesh 14 and the opening area of the duct opening 8b (opening area of the ventilation path surface) become equivalent. When the wire mesh 14 having a convex shape on the side or the wire mesh 14 having a convex shape on the downstream side and having a curved surface as a whole is used as shown in FIG. Was about 2-3%.

FIG. 4 shows the relationship between frequency and noise level. (Noise level measurement position: on the driver's window side) The peak value of the noise level without wire mesh is about 62 dB.
What was A, the peak value of the noise level in the case of b with wire mesh is about 58 dB · A, and the noise level of the peak value is about
It was reduced by about 4 dB · A.

In addition, the overall value of the noise level is about 68.5 dB A when there is no wire mesh over the entire 1/3 octave band frequency.
The overall value of the noise level when the wire mesh is present is b is about 65.5 dB · A.

In other words, the overall noise level was reduced by about 3 dB · A, and it was possible to obtain a very large effect, which was clearly audible.

FIG. 5 shows the relationship between the area ratio in the defroster mode (the substantial opening area of the wire mesh / the opening area of the ventilation path surface) and the air volume, and the relationship between the area ratio and the actual vehicle noise level. (Noise level measurement position: driver's window side) The smaller the area ratio, the smaller the air volume, but without wire mesh the air volume is about 430 m ³ / h and mesh # 40 (25 mm x 2)
It has 40 x 40 holes in an area of 5 mm. ) Wire mesh wire diameter 0.2
It is about 418 m ³ / h at 5 mm, and the reduction in air volume is only about 12 m ³ / h.

The overall noise level without wire mesh is about 6
9.2 dB / A, and the overall noise level of the mesh 20 and wire mesh wire diameter 0.42 mm is about 66.7 dB / A.
The overall noise level has been reduced by 2.5 dB · A.

When the 1/3 octave band frequency is in the range of 315 to 500Hz, the noise level value without wire mesh is about 66.7dB ・ A, and the noise level value with mesh # 20 and wire mesh diameter 0.42mm is about It was 63 dB · A, and the noise level was also reduced by 3.4 dB · A.

Next, the second with the wire mesh 14 installed in the ventilation duct
Examples will be described. In the second embodiment described below, the ventilation duct 9 constitutes an air conditioning duct (upper duct).

As shown in FIG. 8, the heater case 5 and the vent outlet
A wire mesh 14 is provided in the ventilation duct 9 between 15 and 15, as in the first embodiment.

 The operation and effect are similar to those of the first embodiment.

FIG. 9 shows the relationship between frequency and noise level. (Measurement position of noise level: around 150 mm from the center vent outlet) The peak noise level in the case of C without wire mesh is approximately 61.5 dB.
・ The peak value of the noise level in the case of wire mesh d was about 60 dB · A, and the noise level at the peak value was reduced by about 1.5 dB · A.

In addition, the overall value of the noise level in the whole 1/3 octave band frequency without wire mesh is about 69.5 dB · A, and the overall value with wire mesh d is about 68 dBA.

In other words, the noise level was reduced by about 1.5 dB as a whole, and it was possible to obtain a large effect that was audible.

Fig. 10 shows the relationship between the area ratio and the vent air flow in the vent mode, and the relationship between the area ratio and the actual vehicle noise level.
(Measurement position of noise level: 150m from the center vent outlet
(around m) As the area ratio becomes smaller, the air volume is reduced, but the air volume without wire mesh is about 695 m ³ / h, which is 680 m ³ / h when the mesh # 40 and wire mesh diameter is 0.25 mm is 680 m ³ / h. Reduction of only about 10m
It is about ³ / h.

The noise level overall value without wire mesh is approx.
69.5 dB · A, the overall value when the mesh # 30 and the wire diameter of the wire mesh were 0.23 mm was about 67.3 dB · A, and the overall value of the noise level was reduced by about 1.7 dB · A.

1/3 octave band frequency value of the noise level when no wire mesh within the 3.15K～5KH _z mesh # 20 at about 61.5dB · A, the value of the noise level in the case of wire diameter 0.23mm wire mesh is It was about 57.3 dB · A, and the noise level value was also reduced by 4.2 dB · A. Furthermore, it is also effective to provide the wire mesh in the heater case, the heat duct, or in the case around the blower, which is the place where noise is generated in the blower.

The attachment position of the wire mesh may cover a part of the ventilation passage in consideration of the air volume and the like, and the specifications of the wire mesh such as the mesh wire diameter are arbitrarily selected.

Further, by providing the wire net, it is possible to prevent vibration of the duct or the like caused by pressure fluctuation due to air turbulence.

As shown in Fig. 11, the vibration of the duct without the wire mesh occurred between ± 0.2G.

When the wire net is provided, the duct vibration occurs within ± 0.1 G as shown in Fig. 12, and the vibration is reduced to about half that in the case without the wire net.

The air rectifying member in the present invention is clearly distinguished from the louver and the lattice of the air outlet. These are provided at the air outlet outside the duct-shaped case, whereas the air rectifying member in the present invention is provided inside the duct-shaped case.

In the above embodiment, the thread-like member of the air rectifying member is made of metal such as iron or stainless steel, but it is not limited to this, and it is obvious that resin may be used as the material.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram showing an embodiment of the present invention, FIG. 2 is a sectional view showing an essential portion of an embodiment of the present invention, and FIG. 3 is a wind velocity distribution of the embodiment of the present invention. Fig. 4 is a wind velocity distribution chart, Fig. 4 is a characteristic diagram showing the relationship between frequency and noise level in one embodiment of the present invention, and Fig. 5 is a relationship between the area ratio and the air volume and the area ratio in one embodiment of the present invention. Fig. 6 is a perspective view showing a shape of the wire mesh, Fig. 7 is a perspective view showing another shape of the wire mesh, and Fig. 8 is another embodiment of the present invention. 9 is a characteristic diagram showing the relationship between the frequency and noise level of another embodiment of the present invention, and FIG. 10 is a relationship between the area ratio and air volume of another embodiment of the present invention, and FIG. A characteristic diagram showing the relationship between the area ratio and the actual vehicle noise level, FIG. 11 is a characteristic diagram showing the conventional relationship between time and vibration, and FIG. 12 is a characteristic diagram showing the relationship between time and vibration according to the present invention. Figure, FIG. 13 velocity distribution diagram showing the air velocity distribution in a conventional defroster duct, FIG. 14 is a schematic diagram showing the flow of air in a conventional defroster duct. 3 …… Blower, 4 …… Centrifugal fan, 5 …… Heater case, 7
...... Heater core, 7a …… Air mix damper, 8 …… Defroster duct, 9 …… Ventilation duct, 10 …… Heat duct, 14 …… Metal mesh as air rectifying member.

Front page continuation (72) Inventor Shinichi Yoshida 1-1-1, Showa-cho, Kariya city, Aichi Nihon Denso Co., Ltd. JP, U) Actually open 61-7579 (JP, U) Actually open 62-111254 (JP, U)

Claims (2)

[Claims] 1. An air-conditioning case is provided with at least an air-blowing means for generating an air flow and a heat-exchanging means for exchanging heat with the air blown by the air-blowing means. It is configured to blow out into the vehicle interior through an air conditioning duct connected to the downstream side of the air conditioning case, and the downstream end of the air conditioning duct is provided at a predetermined portion in the vehicle interior and opens into the vehicle interior. In an automotive air conditioner, the upstream end of the air conditioning duct and the air conditioning case are connected in such a manner that the wind speed distribution of the air flowing into the air conditioning duct is biased to such an extent that noise is generated in the air conditioning duct. An air rectifying member is provided near the upstream end of the air-conditioning duct to reduce the noise by rectifying the inflowing air by forming a mesh of a plurality of filamentous members. An air conditioner for an automobile, which is characterized in that 2. A defroster duct in which the air-conditioning duct is provided at a position where the downstream side end faces a window glass in a vehicle interior, and an upper duct in which the downstream side end is provided at an upper portion in the vehicle interior. The air conditioner for an automobile according to claim 1, wherein the air conditioner is at least one of the above.