JPS63255117A - Forced air device for car air-conditioner - Google Patents

Abstract

PURPOSE:To form a recess into a resonance damping chamber as well as to improve an abating effect of forced air noise by forming the recess in a substrate of an inside-outside air transfer damper, and installing the cover formed with a hole which interconnects the inside and outside of the recess so as to cover this recess. CONSTITUTION:Each of inside-outside air inlet ports 1a and 1a opened to an inside-outside transfer box 1 is selectively opened or closed by an inside-outside transfer damper 3 supported by a shaft 3 free of rotation. In this case, a substrate 4 is installed in this damper after being clamped to the shaft 3, while a recess 5 is formed in this substrate 4 so as to be projected toward an outside air inlet port 1b. In addition, in this substrate 4, a cover 6 is fixed to a surface to be opposed to the inside air inlet port 1a so as to block up an opening of the recess 5, while a noise absorbing member 7 is attached to an outer surface of the cover 6. Furthermore, a circular hole 8, interconnecting the inside and outside of the recess 5, is opened to the cover 6 and the noise absorbing member 7 each. With this constitution, the recess 5 is formed into a resonance damping chamber, thus forced air noise is abated.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a blower device for a vehicle air conditioner that takes measures to reduce blowing noise.

[Conventional technology]

Of the noise generally generated from air conditioning equipment in vehicles,
For example, the noise generated by a blower that blows air for air conditioning is quite loud, and especially when the blower is installed near the inside air inlet of the air intake duct, the noise generated by this blower is is emitted into the vehicle cabin through the air, causing an audible disturbance to the occupants.

Therefore, as shown in Japanese Patent Application Laid-Open No. 60-35317, sound absorbing materials have been pasted on the inner surface of the intake duct and on the inside/outside air switching damper that selectively opens and closes the inside air inlet and the outside air inlet. Proposals have been made.

According to this, the sound-absorbing material attached to the intake duct and the damper absorbs noise, so a noise reduction effect is recognized.

[Problems to be Solved by the Invention] However, the above-mentioned conventional configuration only involves adhering a sound absorbing material to the intake duct and the damper, and has a problem in that the noise reduction effect is small.

The present invention aims to provide a blower device for a vehicle air conditioner that has a significantly greater noise reduction effect.

[Means for solving problems]

The present invention provides a case that has an air inlet and an air outlet and forms a ventilation path, a blower that is placed inside the case and blows the air inside the case, and a blower that is placed inside the case that blows the air inside the case. In a blower device for a vehicle air conditioner, the damper is rotatably attached to the case and has a recess formed therein, and the damper is configured to cover the recess of the board. The present invention is characterized in that it comprises a cover provided and a sound absorbing member attached to cover the cover, and a hole is formed in the cover and the sound absorbing member to allow conduction between the inside and outside of the recess.

[Effect]

According to the present invention, by forming the recess, if the volume of the recess is V1, the thickness of the cover is L1, and the thickness of the sound absorbing member is L1, and the opening area of the hole that conducts the inside and outside of the above part is S, then by forming the recess, (where, Y is the speed of sound) Sound with a frequency fO corresponding to is absorbed by the resonance damping effect.

Therefore, the volume of the recess V, the thickness L of the cover and the sound absorbing member
1) By appropriately selecting the opening area S of the hole that conducts the inside and outside of the above-mentioned part and matching it to the frequency of the sound to be extinguished, it is possible to attenuate the sound of any frequency, which greatly contributes to noise reduction. .

〔Example〕

The present invention will be described below based on an embodiment shown in the drawings.

First, the installation of the air blower according to the present invention to an automobile will be explained based on FIG. 4, which is a perspective view of the front side of the driver's seat.

In the figure, P is an instrument panel, and an air conditioning unit is arranged in a space on the back side of the instrument panel P so that its longitudinal direction corresponds to the width direction of the vehicle.

The empty one-week unit has a blower A, a cooling unit C, and a heater unit J, and has an outlet that blows out conditioned air to the front seats, E, F, and a heater outlet to the rear seats. G, equipped with a defroster outlet H to the windshield.

The blower A relates to the present invention, and will be described in detail later, but the inside/outside air switching box 1 is connected to the top surface of the scroll casing 10, and the above-mentioned cooling unit C is connected to the side surface. . In addition, this cooling unit C
Although not shown in the figure, an evaporator for cooling is housed therein.

The heater unit J is connected to the downstream side of the cooling unit C, and this heater unit J accommodates a heating heater core (not shown).

Of the above-mentioned air outlets DSE and F, D and E are vent air outlets that primarily emit cold air cooled by the cooling unit C toward the cephalothoracic bones of the occupant, and F is a vent air outlet that is heated in the heater unit J. This is a heater outlet that blows warm air towards the passenger's feet.

The configuration of the air blower A is shown in FIGS. 1 to 3, and will be described below based on this.

An inside/outside air switching box l formed of synthetic resin into a substantially hollow rectangular parallelepiped has an inside air inlet 1a and an outside air inlet 1b opened at a predetermined angle to each other.
a and the outside air inlet 1b are selectively opened and closed by an inside/outside air switching damper 2.

The inside/outside air switching damper 2 is housed in the inside/outside air switching box 1 and supported by a shaft 3. The shaft 3 is rotatably attached to the inside/outside air switching box 1.
Along with the rotation, the inside/outside air switching damper 2 is also rotated together.

The inside/outside air switching damper 2 has a substrate 4 made of metal such as iron that is fixed to the shaft 3 by sbot welding or the like, and the substrate 4 has a recess 5 formed by press working in the center thereof.
For example, it is formed to protrude toward the outside air inlet 1b. Note that this recess 5 is formed in a rectangular shape, as shown in FIG.

A metal cover 6 is fixed to the substrate 4 by spot welding or the like so as to close the opening of the recess 5, that is, on the surface facing the inside air inlet 1a.

A sound absorbing member 7 is adhered to the outer surface of the cover 6 via an adhesive. This sound absorbing member 7 is made of, for example, ester-based urethane resin, and has a sealing function to prevent wind leakage.

A circular hole 8 is opened in the cover 6 and the sound absorbing member 7 to connect the inside of the recess 5 to the outside.

Note that, as shown in FIG. 1, the board 4 is provided with the cover 6
A seal packing 9 for preventing wind leakage made of the same material as the sound absorbing member 7 is adhered to the surface opposite to the surface provided with the sound absorbing member 7 with an adhesive so as to surround the recess 5.

Such an inside/outside air switching box 1 is integrally formed with a resin scroll casing IO.

As shown in FIG. 1, the scroll casing IO is divided by a dividing portion 10c in the vertical direction as shown in the figure.
The inside/outside air switching box 1 is integrally molded on the upper member 10a.

Further, an air inlet member 11 made of metal such as iron is attached to the upper member 10a with screws 12. This air inlet member 11 has a circular bell mouth inlet L.
1a is opened, and the air sucked into the inside/outside air switching box 1 is sucked into the scroll casing 10 through this bellmouth-shaped suction port 11a.

A centrifugal fan 13 is added in the lower member 10b of the scroll casing IO. The centrifugal fan 13 is
It is composed of a plurality of blades 13a and a truncated conical connecting portion tab integrally formed with the blades 13a.

The connecting portion 13b of the centrifugal fan 13 is fixed to the output shaft 14a of the motor 14 using known fixing means such as screws. The motor 14 is attached to the lower member 10b of the scroll casing 10 via a flange 15.

A connection port 16 (shown in FIG. 2) is opened in the scroll casing 10 on the side of the centrifugal fan 13 for blowing air inside the scroll casing 10 toward the downstream side. In this embodiment, this connection port 16 is connected to the cooling unit C mentioned above.

Next, the operation of the embodiment with the above configuration will be explained with reference to FIG. 5.

The inside/outside air switching damper 2 is connected to the inside air inlet 1a of the inside/outside air switching box l.
When the scroll casing lO is opened, the air inside the vehicle compartment is introduced into the inside/outside air switching box l through the inside air inlet 1a, and is sucked into the inside of the scroll casing lO by the centrifugal fan 13. This intake air is blown to the cooling unit C on the downstream side from the connection port IB of the scroll casing IO.

Conversely, when the inside/outside air switching damper 2 opens the outside air inlet 1b, the air outside the vehicle compartment is sucked into the scroll casing 10 from the inside/outside air switching box l through the outside air inlet 1b, and this intake air Scroll casing
Air is blown to the cooling unit C on the downstream side from the connection port 16 of the O.

In this way, air is sucked into the scroll casing lO from the inside/outside air switching box l by the suction action of the centrifugal fan 13, and this intake air is sent to the cooling unit C on the downstream side.
When blowing air to the centrifugal fan 13, turbulence occurs in the flow of air passing through the centrifugal fan 13, and noise is generated. Such noise is radiated downstream and in the direction of the inside/outside air switching box l.

When the air inside the vehicle interior is sucked into the scroll casing lO, the inside/outside air switching damper 2 is connected to the inside air inlet 1a.
Since this is open, the air blowing noise that has been emitted to the inside/outside air switching box 1 is emitted into the vehicle interior through this inside air introduction port 1a, thereby increasing the noise in the vehicle interior.

However, in this embodiment, a recess 5 is formed in the substrate 4 of the internal/external air switching damper 2, and this recess 5 is made conductive with the inside of the internal/external air switching box 1 through the circular hole 8. It becomes a resonant damping chamber and absorbs noise.

To explain in more detail, the noise generated by the centrifugal fan 13 is radiated to the inside and outside air switching box 1, but the sound that reaches the inside of the inside and outside air switching box 1 is transmitted through the circular hole 8 to the recess 5 of the inside and outside air switching damper 2. enter in. This recess 5 functions as a resonance damping chamber and acts to absorb noise, thereby reducing noise.

Specifically, the volume of the recess 5 is equal to the thickness of the V1 cover 6 and the sound absorbing member 7, and a hole 8 is formed to provide electrical continuity between the inside and outside of the recess 5.
Assuming that the opening area of is S, by forming the recess 5, sound at a frequency fO corresponding to (T is the speed of sound) will be absorbed by the resonance damping effect.

By the way, characteristic A shown by the solid line in FIG.
depth L2 - 20mm, thickness L1 of sound absorbing member 7 = 6mm
, are sound pressure level measurement values when the diameter D of the circular hole 8 is set to 0 mm, the horizontal axis shows the frequency H2, and the vertical axis shows the sound pressure level dB. Characteristic A shown by the broken line in FIG. 5 is the sound pressure level measurement when the depth of the recess 5 is set to L2-0 and the diameter of the circular hole 8 is set to D-0, that is, when the damper 2 without the recess 5 is used. It is a value.

As can be understood from this characteristic diagram, the damper 2 with the recess 5 provided in the characteristic A has resonance damping around the frequency of 280 Hz compared to the damper 2 with the recess 5 in the characteristic B, and the damper around this frequency Effective in noise reduction.

Therefore, by appropriately selecting the volume v1 of the recess 5, the thickness L1 of the cover 6 and the sound absorbing member 7, and the opening area S of the hole 8 that conducts the inside and outside of the above-mentioned part 5 to match the frequency of the sound to be extinguished, an arbitrary value can be obtained. It can attenuate the sound frequency.

For this reason, the blowing noise reaching the inside/outside air switching box 1 is reduced by the resonance damping effect of the recess 5 before being released into the passenger compartment through the inside air introduction port 1a, and the noise is reduced by the resonance damping effect of the recess 5. Since the amount emitted is reduced, the noise inside the vehicle is reduced.

Note that the air blowing noise that reaches the inside/outside air switching box 1 hits the inside/outside air switching damper 2, is reflected there, and is emitted into the passenger compartment from the inside air inlet 1a. Since the sound absorbing member 7 is attached to the surface that becomes the reflective surface, when the noise is reflected, the sound is absorbed by the sound absorbing member 7, and this also reduces the noise emitted into the passenger compartment from the inside air inlet 1a. Currently at work.

Note that the present invention is not limited to the above-described embodiments, and various modifications as described below are possible.

(1) The location of the blower is not limited to the inside of the scroll casing 10 directly below the inside/outside air switching box 1 as in the embodiment.
The cooling unit C1 may be located downstream of the heater unit J.

(2) The air conditioner is not limited to one having a heat exchanger as described above, but may also be one that only performs ventilation.

(3) The damper of the present invention is not limited to an inside/outside air switching damper, but may be applied to an outlet switching damper or a temperature control damper that adjusts the temperature of outlet air by adjusting the amount of air flowing into a heat exchanger. Needless to say.

(4) In the above embodiment, the concave portion 5 was formed only in the substrate 4 of the internal/external air switching damper 2, but a concave portion was provided in the substrate 4 and the cover 6, respectively, and the substrate 4 and the cover 6 were brought into contact with each other. In some cases, it may be configured to have one recess.

(5) In the above embodiment, the cover 6 and the sound absorbing member 7 are provided with the circular hole 8, but the shape of the hole is not circular but may be of various shapes.

〔Effect of the invention〕

As described above, according to the present invention, the recess formed in the substrate of the damper becomes a resonant damping chamber and can attenuate sound of any frequency, thereby significantly increasing the noise reduction effect.

[Brief explanation of drawings]

The drawings show one embodiment of the present invention, and FIG. 1 shows 1 in FIG.
2 is a plan view of the blower A, FIG. 3 is a perspective view of the inside/outside air switching damper, FIG. 4 is a perspective view of the front side of the driver's seat showing an example of the configuration of the vehicle air conditioning unit, FIG. 5 is a characteristic diagram of sound pressure level. A...Blower, C...Cooling unit, J...
Heater unit, D, E, F...Air outlet, G...Heater outlet, H...Defroster outlet, ■...Inside/outside air switching box, la...Inside air inlet, lb. ... Outside air inlet, 2 ... Inside and outside air switching damper, 3 ... Shaft,
4... Board, 5... Recess, 6... Cover, 7...
- Sound absorbing member, 8... Hole, 10... Scroll casing, 13... Centrifugal fan, 14... Motor. Applicant's agent Patent attorney Takehiko Suzue, ° 1 Figure 2 [

Claims (2)

[Claims] (1) A case that has an air inlet and an air outlet and forms a ventilation path; a blower that is placed inside the case and blows the air inside the case; and a blower that is installed inside the case and blows the air in the ventilation path. In a blower device for a vehicle air conditioner, the damper is rotatably attached to the case and includes a substrate having a recess formed therein, and a substrate configured to cover the recess. An air blower for a vehicle air conditioner, comprising: a cover provided on the cover; and a sound absorbing member adhered to cover the cover, and a hole is formed in the cover and the sound absorbing member to allow conduction between the inside and outside of the recess. Device. (2) Claims characterized in that the air inlet has an inside air inlet and an outside air inlet, and the damper is an inside/outside air switching damper that selectively opens and closes both the inlets. A blower device for a vehicle air conditioner according to item 1.