JPH07172151A - Duct for ventilation - Google Patents

Abstract

PURPOSE:To fully exhibit a spurn water effect while maintaining ventilation efficiency. CONSTITUTION:A duct for ventilation set up on a vehicle is provided with a frame 1 in which a exhaust port 13 is formed for exhausting air inside of a compartment to the outside thereof, a tabular flap 2 which is mounted outside of the compartment of the frame 1 in such a manner as covering the exhaust port 13 and then being opened only in the direction to the outside of the compartment by a pressure difference between pressures inside and outside of the compartment; and a spurn water 3 which is formed in a cylindrical to shape on the back compartment side of the frame 1 communicated with the exhaust port 13 and which has a height of 1.2 times exhaust port heights a1, a2 or more.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a ventilation duct that secures a ventilation amount inside a vehicle while the vehicle is running, and prevents foreign matter, exhaust gas and the like from entering the vehicle interior when the vehicle is stopped.

[0002]

2. Description of the Related Art At the rear of an automobile, there is a ventilation duct for replacing air in the vehicle interior during traveling. Since the relatively narrow vehicle interior is easily polluted by people's breathing, cigarette smoke, etc., fresh air is taken in from the front of the vehicle compartment, etc., and is concentrated through the exhaust duct of the ventilation duct provided at the rear of the vehicle body. Discharge outside the vehicle. In the frame body 1 forming the discharge port 13,
The flap 2 is attached, and while the vehicle is traveling, the opening degree of the flap 2 is changed according to the pressure difference between the inside and outside of the vehicle to adjust the air volume (FIG. 7). Here, in consideration of ventilation and anti-fog property, it is desirable that the flap 2 be opened under the condition that the pressure difference between the inside and the outside of the vehicle is as small as possible. On the other hand, the flap 2 is
The outlet 13 is covered when the vehicle is stopped, etc., and serves to prevent foreign matter (dust, dust, etc.) from entering the vehicle interior from the outside. Furthermore, when the vehicle interior pressure becomes lower than the external pressure, such as when a window is opened during traveling, the flap 2 is in close contact with the exhaust port 13 to prevent exhaust gas suction. Such a ventilation duct A is attached to any of the back of a bumper, a door, and a rear pillar of an automobile.

[0003]

Under these circumstances, when the ventilation duct A is attached to the back side of the bumper, water entry becomes a problem. Therefore, the ventilation duct A prevents water from entering the vehicle interior by providing the tubular water repellent 3 having a water immersion height or more on the rear vehicle compartment side of the frame body 1 (FIG. 7).
In particular, depending on the vehicle type, the flood height of the vehicle is set,
Installation of the water return 3 is indispensable. However, when the water return 3 is provided, the water return height b tends to be set lower than the outlet height a, and here, as shown in FIG. 6, the ventilation efficiency decreases as the tubular water return height b increases. It is generally known to do. Therefore, while ensuring ventilation efficiency, on the other hand, a contradictory problem of trying to prevent the intrusion of water is faced, and as a result, the ventilation duct A is enlarged and the structure of the flap 2 is changed. I was struggling to find a way out.

The present invention solves the above problems, and an object of the present invention is to provide a ventilation duct capable of exhibiting a sufficient water return effect while maintaining ventilation efficiency.

[0005]

DISCLOSURE OF THE INVENTION A ventilation duct of the present invention is a ventilation duct attached to a vehicle, in which a frame body having a discharge port for discharging the air inside the vehicle to the outside of the vehicle and the frame body are provided. A plate-like flap that is provided to cover the discharge port outside the vehicle and that is opened only in the direction toward the vehicle outside due to the pressure difference between the inside and outside of the vehicle, and is formed in a tubular shape on the rear vehicle side of the frame. And a water return pipe communicating with the discharge port and having a height of 1.2 times or more the height of the discharge port.

[0006]

In the range where the water return height b is lower than the outlet height a as in the conventional case, as shown in FIG. 7, the upper flap 2 is opened, but the lower flap 2 is affected by uneven flow and wind The flow gets worse. Therefore, the higher the water return 3 is, the more uneven the opening of the flap 2 is, and the ventilation efficiency (ventilation amount) tends to decrease. However, when the water return height b becomes 1.2 times the outlet height a or more, the water return 3 itself becomes a chimney shape, and this time it has a rectifying function, and each of the flaps 2 of the flap 2 is provided as shown in FIG. The gap is improved without any bias. Then, the flow of air becomes uniform and the ventilation efficiency (ventilation amount) is increased, and at the same time, the water repelling effect can be sufficiently exerted.

[0007]

EXAMPLES The present invention will be described in detail below based on examples. (1) Configuration of Ventilation Duct FIG. 1 is an overall perspective view of the ventilation duct according to the present invention, and FIG. 2 is a vertical sectional view of FIG. Reference numeral 1 denotes a slanted wall 11, a horizontal wall 15 continuously provided at the lower edge of the slanted wall 11, and the slanted wall 1.
The vertical wall 12 that is continuously provided at the upper end of 1 and the inner end of the horizontal wall 15.
A frame composed of and is shown. The inclined wall 11 has two square outlets 13 formed vertically. The exhaust port 13 plays a role of letting air in the vehicle compartment escape to the outside of the vehicle. Here, the outlet height a (a = a ₁ + a ₂ ) is 50 mm, and the outlet W width W is 60 mm. The outlet 13 is surrounded by an inclined wall 11 having an inclination angle of about 60 degrees. Most of the inclined wall 11 serves as a contact surface with the flap 2 described later. The vertical wall 12 of the frame 1 is provided with mounting holes 14 for mounting on the vehicle body S at four corners.
It is provided in the place.

Reference numeral 2 indicates a flap which is slightly larger than the discharge port 13 and is provided outside the vehicle so as to cover the flap. The flap 2 is provided so as to be placed on the inclined wall 11 around the discharge port 13. The flap 2 is a rectangular plate-like body, and the upper end of the flap 2 is fixed to the frame body 1 by heat welding or screws 5. Instead of this, a hole may be provided in the vicinity of the upper edge of the inclined wall 11, and a locking piece may be provided so that the flap 2 is hung from this hole. The flap 2 is made of flexible ethylene propylene diene copolymer rubber (JIS A hardness is 50 degrees) and is in a swingable state. When the pressure inside the vehicle is higher than the pressure outside the vehicle, such as when the vehicle is running, the flap 2 separates from the discharge port 13 even if the pressure difference is relatively small, and the discharge port 1
This is for opening 3 (FIG. 2). Flap 2
Is configured to open only when the air inside the vehicle is discharged toward the outside of the vehicle, and normally covers the discharge port 13 by its own weight. Further, even when the vehicle interior pressure becomes lower than the vehicle exterior pressure, the flap 2 is in close contact with the inclined wall 11 around the discharge port 13 to cover the same. here,
The flap 2 is preferably blended with ferrite to improve the function of maintaining close contact with the inclined wall 11 to which a magnetic material is attached (or magnetized) in order to prevent a dance on the contact surface with the inclined wall 11 during traveling. Becomes Alternatively, the flap material may be filled with a filler to make it heavier.

Reference numeral 3 indicates a water repellent formed with the frame body 1. The water return 3 surrounds the exhaust port 13 on the rear passenger compartment side of the frame 1 and communicates with it, while the other end is bent and then extends vertically upward to take in the passenger compartment air on the upper surface. 31 is formed (FIG. 2). The water return height b is 110 mm, which is more than twice the outlet height a (50 mm). This is because the desired draining efficiency (66%) is obtained and the draining effect is ensured to prevent water from entering the vehicle interior through the discharge port 13. The opening area of the inflow port 31 is about 29 cm ² .
The frame body 1 and the water drain 3 are integrally made of polypropylene resin. In this way, the ventilation duct A is fixed to the vehicle body S using the mounting hole 14, and when the air pressure inside the vehicle is increased by taking in fresh air from the front portion of the vehicle interior or the like, the flap due to the pressure difference inside and outside the vehicle interior. 2 separates from the outlet 13. Then, the vehicle interior air is exhausted to the outside of the vehicle through the inflow port 31 only from the exhaust port 13 in a concentrated manner.

(2) Performance Test and Evaluation For the ventilation duct A according to the present invention, the following test was conducted in order to examine the influence of the water return height b on the ventilation performance. Ventilation efficiency test In this test, the shape and size of the ventilation duct A are adopted, and only the water return height b is changed to examine the relationship between the water return height b and the ventilation efficiency E. is there. The outlet height a = 50 mm is fixed, and the water return height b is 0 to 1
It is changed in the range of 90 mm. Figure 4 shows the test equipment.
Shown in. The device 4 has an opening 4 on the opposite side surface of the device body 41.
2, 43 are provided, a fan 44 is attached to one side, and a ventilation duct A to be tested is attached to the other side.

The cylindrical tube 4 covers the fan 44.
5 is fixed to the main body 41 of the apparatus, and a nozzle 451 is provided in the cylindrical tube 45. By connecting the nozzle 451 and the manometer 46 with the tube 47, the static pressure P ₂ in the cylindrical tube 45 can be measured. Further, a nozzle 411 is also provided above the device body 41, and a static pressure P in the device body 41 is measured by a manometer 49 connected via a tube 48.
_I can measure one.

The following measurement of ventilation resistance was performed using the above apparatus. First, the ventilation duct A having a predetermined water return height b was attached to the opening 43 (FIG. 4). Then
The fan 44 was activated, and air was blown into the apparatus main body 41 from the outside (one of the inlets of the tubular tube 45) and was vented so as to be discharged from the ventilation duct A. The static pressure was measured by the manometer 46, and the ventilation volume was obtained from the conversion table (Bellmouth pressure VS air volume). On the other hand, the ventilation resistance (P ₁ −P ₀ ) was obtained by subtracting the external pressure P ₀ from the measured value of the static pressure P ₁ of the manometer 49. Adjust the ventilation volume of the fan 44 so that the ventilation volume is 5
For the three cases of 0, 60, 70 m ³ / h, the water return height b was variously changed, and a curve of ventilation efficiency with respect to the water return height b as shown in FIG. 5 was obtained.

In FIG. 5, the ventilation efficiency E is obtained by the following equation. E [%] = {F ₀ / F} × 100 Here, F ₀ is obtained as follows. F ₀ = {(ρ / 2) × (1 / 0.36) ² / (P ₁ −
P ₀ )} ^1/2 × V _a V _a is the ventilation amount [m ³ / h]. Also, ρ = 1.293 / {(1 + 0.00367t) ×
9.8}. t indicates a temperature [° C.]. On the other hand, the above F adopts the actual opening area (projected area) of the ventilation duct A. That is, F = a × W = (a ₁ + a ₂ )
It is represented by × W (FIGS. 1 and 3).

Test Results and Effects From FIG. 5, until the water return height b becomes 1.2 times the outlet height a, as is conventionally known, the higher the water return height b, the more the ventilation efficiency. It was found that E decreased. However, the water return height b with respect to the outlet height a, that is, b / a, has a boundary of 1.2, and when it exceeds this, the ventilation efficiency E starts to increase, and the desired ventilation amount can be easily obtained. There was found. For example, a ventilation duct A that secures ventilation efficiency E = 55% when the water return height b is 40 mm.
When installing the ventilation duct A on a bumper or the like, by setting the water return height b to 90 mm, the water return effect can be sufficiently exerted while obtaining the desired ventilation efficiency E (the portion shown by the broken line in FIG. 5). ). FIG. 5 shows that not only can water be prevented from entering the vehicle interior, but ventilation efficiency E can also be increased by further increasing the water return height b, if necessary. A suitable value is 1 for the water return height b.
The case was 10 mm (FIG. 5). b / a = 2.2
This is because the ventilation efficiency E increases up to, but it hardly changes when the ventilation efficiency E is higher than that, and on the other hand, if the water return height b is as high as this, it is possible to sufficiently prevent the intrusion of water. Thus, b / a
The ventilation duct A having a value of 1.2 or more not only prevents water from entering the vehicle interior by increasing the water return height b, but also increases the ventilation efficiency E, thereby increasing the ventilation and anti-fog in the vehicle interior. Etc.

The present invention is not limited to those shown in the above-mentioned embodiment, but can be variously modified within the scope of the present invention depending on the purpose, application and the like. For example, the sizes, shapes, and the like of the frame body 1, the flap 2, the water return member 3, and the discharge port 13 are not limited to the present embodiment, and various changes can be made according to the purpose.

[0016]

As described above, the ventilation duct according to the present invention can exert a sufficient water return effect while ensuring a desired ventilation amount, and exhibits an excellent effect of ensuring comfort in the vehicle compartment.

[Brief description of drawings]

FIG. 1 is an overall perspective view of a ventilation duct according to an embodiment.

FIG. 2 is a vertical cross-sectional view of the ventilation duct of FIG.

FIG. 3 is an explanatory view showing a water return height and a discharge port height.

FIG. 4 is an explanatory diagram showing a ventilation efficiency test device.

FIG. 5 is a graph showing the relationship between water return height and ventilation efficiency.

FIG. 6 is a graph showing the relationship between water return height and ventilation efficiency.

FIG. 7 is an explanatory diagram showing the influence of the water return height on the ventilation volume.

FIG. 8 is an explanatory diagram showing the influence of the water return height on the ventilation volume.

[Explanation of symbols]

 1 Frame 13 Outlet 2 Flap 3 Water return height A Ventilation duct

Claims (1)

[Claims] 1. A frame body (1) in a ventilation duct attached to a vehicle, the frame body (1) having an exhaust port for exhausting vehicle interior air to the outside of the vehicle, and a cover for the exhaust port outside the frame body. And a plate-like flap (2) that is opened to only the outside of the vehicle due to a pressure difference between the inside and outside of the passenger compartment, and is formed in a tubular shape on the rear passenger compartment side of the frame and communicates with the discharge port. A ventilation duct provided with a water baffle (3) having a height 1.2 times or more the height of the discharge port.