JPS6175013A - Automobile air conditioning system - Google Patents

Abstract

PURPOSE:To reduce noise radiated from an inside air suction port, by providing such an arrangement that the inside air suction port is opened to an intake duct connected to the upstream end of a ventilated passage and extended toward the center of a vehicle, remote from a blower. CONSTITUTION:An inside air suction port 4 is opened to one side surface of a cawl box 3 which is opposed to an instrument panel 57, and is set at a position near to the center of a vehicle but distant from a vehicle side plate 70 more than 1/4 of the width of the vehicle, that is, the position is near to the center of the instrument panel 57 but remote from the intake port 2 of a blower 51. With this arrangement the suction port 4 is far from the intake port 2 of the blower 51, and therefore, noise radiated from the suction port 2 is damped during passage through the cawl box 3. Further, the radiated noise from the suction port 2 is vertically directed while the cawl box 3 is horizontally laid, and the propagations are different from each other so that the damping effect may be enhanced while resonance may be prevented. accordingly, radiated noise may be reduced.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to noise reduction in automotive air conditioners.

[Conventional technology]

Generally, an air conditioner for an automobile has a resin case 50 that forms a ventilation path, as shown in FIG.
An inside air suction port 60 and an outside air suction port 61 are opened on the most air upstream side, and both can be switched open and closed by an inside/outside air switching damper (not shown). A blower 51 is provided inside the case downstream of the blower 51, and an evaporator 52 that cools the surrounding air by evaporating refrigerant of a refrigeration cycle (not shown) is provided downstream of the blower 51.
A hot water type heater core 53 is disposed downstream of this and heats the surrounding air using the cooling water of an automobile engine (not shown) as a heat source. Furthermore, inside the case 50,
In addition to a temperature-adjusting air-nox damper 54 that changes the ratio of air passing through the heater core 53 and its sides, a plurality of outlet switching dampers (not shown) are provided to switch open and close the outlet states to various outlet ports 55. .

The case 50 having the internal configuration described above is disposed across the width of the vehicle in a space between the dash board 56 that partitions the engine room A and the vehicle interior B, and the instrument panel 57.

Incidentally, in recent years, as vehicles have become more sophisticated and automobile technology has progressed, it has been desired to reduce noise inside the vehicle interior.

Under these circumstances, noise emitted from automobile air conditioners has become a problem.

The inventors of the present invention investigated the noise emitted from automobile air conditioners and found the following. At that time, a microphone was placed near the ear of the passenger in the driver's seat, and the noise was measured in internal air intake mode.

First, the loudest part is that emitted from the inside air suction port 60, which accounts for 65% of the noise emitted from the entire air conditioner. Next is the air outlet 55, accounting for 26% of the total, and the smallest portion is emitted through the case, accounting for 9% of the total.

As described above, according to the measurement results of the present inventors, it has been found that among the noises radiated from the automobile air conditioner, the noise from the inside air intake port 60 is the loudest.

Based on this experimental result, the inventors investigated the reason and came to the following conclusion.

In other words, in the conventional automobile air conditioner, as shown in FIG. 11, the inside air suction port 60 is opened at a position very close to the blower 51. Since it opens into the interior B, wind noise from the fan of the blower 51, motor rotation noise of the blower 51, and noise due to ventilation resistance within the suction system duct are radiated into the vehicle interior through the inside air suction port 60.

Furthermore, since the inside air suction port 60 opens near the vehicle side surface 70, the low frequency noise radiated from the inside air suction port 60 is reflected from the vehicle side surface and resonates inside the vehicle interior, so that it is not harmful to the occupants inside the vehicle interior. It turns out that it feels bigger.

[Problem that the invention seeks to solve]

Therefore, it is a technical object of the present invention to reduce the noise emitted from the air conditioner for an automobile, especially the noise emitted from the inside air intake port.

[Means for solving problems]

In order to achieve the above-mentioned technical problem, the present invention includes a ventilation passage having a heat exchanger for heating or cooling air inside and a blower for supplying air to the heat exchanger, and the ventilation passage is installed in a vehicle. An air conditioner for an automobile formed across the width direction includes: a suction duct connected to an air upstream end of the ventilation passage and extending toward the center of the vehicle; and an outside air intake port opened to the suction duct or the ventilation passage. , Adopts a technical means comprising an inside air suction port opened in the suction duct, and an inside/outside air switching member for switching the ratio of air introduced from the inside air suction port and the outside air suction port.

[For production]

According to the above-mentioned technical means, the inside air suction port is opened by the suction duct at a position a predetermined distance away from the blower toward the center of the vehicle, so that the fan wind noise and motor rotation noise generated in the blower are reduced. is attenuated as it passes through the suction duct before being radiated from the inside air suction port.

Moreover, the opening position of the inside air intake port is on the center side of the vehicle, which is a predetermined distance away from the air blower, so even if the blower is installed near the side of the vehicle, the opening position of the inside air intake port is
It is separated from the side of the vehicle. Therefore, the resonance phenomenon in the vehicle interior of the noise radiated from the inside air intake port is prevented.

〔Effect of the invention〕

Therefore, according to the present invention, the inside air suction port is moved away from the noise source and the resonance phenomenon of noise in the vehicle interior is prevented, so the synergistic effect of these two methods greatly reduces the noise radiated from the inside air suction port. can.

In addition, it is possible to reduce the part of the noise that traditionally accounts for the highest proportion of the noise emitted from automotive air conditioners, which results in effective noise reduction within the vehicle interior, significantly reducing the noise within the vehicle interior. It has the effect of reducing

〔Example〕

The present invention will be explained below with reference to embodiments shown in the drawings. Second
The figure shows a view of the instrument panel as viewed from inside the vehicle. 57) and the dash panel, from the center of the instrument panel to the passenger seat side. Inside this case 1, there is a first
Similar to the conventional example shown in FIG. 0, an evaporator 52 and a heater core 53 are housed, and air blown from a blower 51 provided upstream thereof is cooled and heated, respectively. Further, a vent outlet 55a is provided on the upper side of the instrument panel to blow out cold air cooled by the evaporator 52 toward the cephalothorax, and a vent outlet 55a is provided below the instrument panel to blow out the cold air cooled by the evaporator 52 toward the cephalothorax. A heater outlet 55b is provided to blow out air toward the feet of the heater.
On the upper surface of the instrument panel, there is a defroster outlet 55 that blows hot air heated by the heater core 53 or cold air cooled by the evaporator 51 toward the windshield 58.
c is provided.

The blower 51 is connected to the vehicle side plate 7 as shown in FIG.
A Shiro 7 Cofan, which has many blades, is used as a fan for blowing air. Therefore, the blower 51 sucks air vertically from above and blows it horizontally, as shown by the arrows in FIG. As shown in FIG. 1, the intake port 2 of this blower 51 is opened at a position close to the vehicle side plate 70 of the iron cowl box 3 provided in the upper space between the engine room A and the vehicle compartment B. ing. In a conventional automobile air conditioner, the cowl box 3 is used as an outside air introduction passage, and serves as a space for storing a wiper link (not shown). As shown in FIG. 3, a heat insulating sheet 32 for soundproofing is attached to the outer surface of the cowl box 3 on the passenger compartment side and the outer surface of the dash board 56 on the passenger compartment side. Furthermore, a heat insulating material 31 such as urethane resin is attached to the inner surface of the cowl box 3. Therefore, when the air conditioner performs cooling operation in the inside air mode, the cold air in the vehicle interior B drawn into the cowl box 3 from the inside air intake port 4 is
When passing through the inside of the cowl box 3, the temperature is not increased and the air is sucked into the suction port 2.

As can be clearly seen from FIG. 2, the inside air intake port 4 is opened on the side surface of the cowl box 3 facing the instrument panel 57, and is located approximately at the center of the instrument panel 57 in the vehicle width direction.

However, the position of this inside air intake port 4 is not necessarily at the center of the instrument panel, but it is preferable to be as far away from the vehicle side plate 70 and the intake port 2 as possible, and at least 1/4 or more of the width of the vehicle from the vehicle side plate 70 toward the center. It is necessary to provide

The outside air intake port 5 is opened in the bonnet near the windshield and communicates with the inside of the cowl box 3, as in the conventional case, but in this embodiment, it is located on the upstream side of the inside air intake port 4. .

The inside air suction port 4 is rotatably provided with a damper 6, which is an inside/outside air switching member that opens and closes this.

FIG. 4 is an enlarged view of the vicinity of the damper 6, and the damper 6 is
A wire 10 is attached to a bearing 7 provided in the vehicle body so as to be rotatable around a shaft 8, and a wire 10 is attached via a link 9 that is integrated with the shaft 8. It can be moved using a switching lever. Note that the damper 6 has a shape and structure that can block air introduction from the inside air suction port 4 and the outside air suction port 5 communicating with the cowl box 3 depending on its position.

Next, the operation of this embodiment having the above configuration will be explained.

First, when introducing outside air, when the passenger manually switches the inside/outside air switching lever to the outside air introduction position, the wire 10 is connected to the W
When pulled in the direction, the damper 6 rotates and is pressed against the X side of the side surface of the cowl box 3 through the link 9, closing the inside air suction port 4 and opening the passage in the cowl box 3. As a result, the outside air introduced from the outside air suction port 5 is guided to the blower suction port 2 through the cowl box 3 as in the conventional layout.

In this case, the outside air suction port 5 is opened to the outside of the vehicle, so the sound radiated from the blower is radiated outside the vehicle, and the noise from the blower is attenuated when passing through the inside of the case 1, and is brought into the passenger compartment. The radiated noise is emitted from each air outlet 55a, 55b.
, 55c, and noise due to ventilation resistance inside the case 1.

Next, when the inside/outside air switching lever is switched to the inside air introduction position, the wire 10 is pulled in the Z direction in FIG. 3, and the damper 6 is pushed toward the Y side via the link 9.

Therefore, the passage through the cowl box 3 is blocked, the inside air suction port 4 is opened, and the air inside the vehicle compartment is sucked through the inside air suction port 4 and guided through the cowl box 3 to the rib blower suction port 2.

In this case, unlike when outside air is introduced, the noise radiated from the blower 51 is emitted into the vehicle interior from the inside air suction port 4.

However, according to this embodiment, the opening position of the inside air suction port 4 is located near the center of the instrument panel, which is optically separated from the suction port 2 of the blower 51, so that the noise emitted from the suction port 2 passes through the cowl box 3. It is attenuated when Moreover, according to this embodiment, the sound radiated from the intake port 2 is radiated in the vertical direction of the vehicle, but since the cowl box 3 is provided in the horizontal direction of the vehicle, the sound propagation direction is different, and the cowl box It reaches the inside air suction port 4 while reflecting inside the inside air 3. Further, in this example, the inside air suction port 4 is separated by light from the vehicle side plate 70.
Since it is provided in the center of the instrument panel, resonance phenomenon of low frequency noise of about 200 Hz is prevented.

Therefore, the noise level radiated into the vehicle interior from the inside air intake port 4 is greatly reduced compared to the conventional case.

Next, the noise reduction effect in this example will be explained.

Fig. 5 shows the noise level distribution in the vehicle interior in a conventional example in which the inside air intake port 4 is provided close to the vehicle side plate and the air intake port, and Fig. 6 shows the noise level distribution in the vehicle interior in a conventional example in which the inside air intake port 4 is provided near the center of the instrument panel. The noise level distribution of this example is shown. In FIGS. 5 and 6, El-ES marks indicate measurement points near the occupant's ears, and O marks schematically indicate the noise level at each measurement point.

In addition, Ebi...driver's seat, E2...passenger seat, E3...
Right side of the rear seat, E4...center of the rear seat, E5...left side of the rear seat. Table 1 shows the specific measurement results. However, the noise measurement frequency was 200 Hz or less.

□ As is clear from this table, according to this example, the noise is reduced by about 2 to 4 dB (A) compared to the conventional example.

Next, other embodiments of the present invention will be described.

(1) The inside/outside air switching member is not limited to the above-mentioned damper 6, but may be combined with a rotary complete damper shown in FIGS. 7 to 9. This rotary complete damper 11 has an inner cylinder 12 and an outer cylinder 13 that slidably accommodates the inner cylinder 12.

Inner circle? A shaft 14 is joined to the closed end of the fi 12, and when the inner cylinder 12 is housed in the outer cylinder 13, the shaft 14 projects outward from a hole 15 opened at the closed end of the outer cylinder. It is joined to the link 15. Further, the outer cylinder 13 is provided with two openings 13a and 13b, and the inner cylinder 12 is provided with one opening 12a.

Therefore, when the outer inner cylinder 13 is disposed inside the cowl box 3, if the opening 13a is located upward and the opening 13b is opposed to the inside air suction port 4, then the opening 12a of the inner cylinder 12 is positioned upward. When the inner cylinder 12 is rotated, the outside air introduction mode is set as shown in FIG.

On the other hand, as shown in FIG. 9, the opening 12a of the inner cylinder 12 is
If the inner cylinder 12 is rotated so that it is in a horizontal position,
Enter shy air introduction mode.

(2) The suction duct of the present invention is not limited to the above-mentioned cowl box 3, but as shown in FIG. An opening 19 may be provided on the side surface of the box 3, and a duct 21 for sucking inside and outside air may be provided in this opening 19, which projects toward the engine room A side. Therefore, in this case, the ventilation path is longer than when the cowl box 3 is used as a suction duct, and since it has a bent part in the middle, the noise level is further reduced.

Further, in addition to the above, the suction duct exclusively for inside air may be connected as a separate body to the conventional inside air suction port 60 shown in FIG. 10, and the other end may be arranged in the center of the instrument panel.

1(3) If a sound absorbing material such as foamed urethane is attached to the inner surface of the damper 6 and the cowl box 3 which is the suction duct, the noise reduction 'lfj and the effect can be further enhanced.

(4) The damper 6 for switching between inside and outside air not only opens and closes the inside air suction port 4 and the outside air suction port 5, but also opens and closes the inside air suction port 4.
It goes without saying that a device that is held at an intermediate position between the air inlet and the outside air suction port 5 and sucks in both inside air and outside air has the same noise reduction effect as described above.

(5) It goes without saying that instead of using the cowl box 3 as a duct as described above, a duct made of a heat insulating material may be provided inside the cowl box 3.

(6) The location of the blower is not limited to the vicinity of the vehicle body side plate 70, but also in the case of a suction type blower installed in the center of the instrument panel 57, the upstream end of the case 1 is opened in the cowl box 3 as described above. The same applies if

[Brief explanation of drawings]

FIG. 1 is a perspective view of the vicinity of the automobile cowl box showing the features of the present invention, FIG. 2 is a plan view of the instrument panel portion showing the features of the present invention, and FIG. 3 is a sectional view taken along line XX in FIG. FIG. 4 is a perspective view of the damper for switching between inside and outside air of the present invention, and FIG.
FIG. 6 is an explanatory diagram showing the noise distribution in the vehicle interior by the conventional device, FIG. 6 is an explanatory diagram showing the noise distribution in the vehicle interior by the device of the present invention, and FIG. 7 is an explanatory diagram showing another embodiment of the inside/outside air switching member of the present invention. The assembly drawings shown in Figures 8 and 9 are schematic sectional views of Figure 7 and Figure 1.
FIG. 0 is a perspective view showing another embodiment of the suction duct, and FIG. 11 is a schematic sectional view of a conventional automobile air conditioner. 2...Intake port, 3...Cowl box (suction duct), 4...Inside air intake port, 5...Outside air intake port, 6...
- Damper (internal and external air switching member), 11... Rotary damper (internal and external air switching member), 21... Duct (suction duct), 52... Evaporator, 53... Heater core, 57... Blower, 60... Inside air intake port, 61...
・Outside air intake.

Claims (4)

[Claims] (1) In an air conditioner for an automobile, the air conditioner is equipped with a ventilation passage having a heat exchanger that heats or cools air inside, and a blower that supplies air to the heat exchanger, and the ventilation passage is formed across the width direction of the vehicle. , a suction duct connected to the air upstream end of the ventilation passage and extending toward the center of the vehicle; an outside air suction port opened to the suction duct or the ventilation passage; and an inside air suction port opened to the suction duct. and an inside/outside air switching member that switches the ratio of air introduced from the inside air suction port and the outside air suction port. (2) The air conditioner for an automobile according to claim 1, wherein the blower is located at the most air upstream side of the case and is disposed near a side plate of the vehicle. (3) The air conditioner for an automobile according to claim 1 or 2, wherein the suction duct is a cowl box of a vehicle. (4) The automobile air conditioner according to claim 3, wherein the inside/outside air switching member is a damper rotatably provided in the cowl box.