DESCRIPTION IMPURE AIR DISCHARGE SYSTEM FOR VEHICLES

Subject of the invention

This invention relates to the impure air discharge system for buses and similar public transportation vehicles, which discharge the impure air in the vehicle by the unidirectional natural flow, which is created through the pressure difference that occurs due to the speed of the vehicle.

State of Prior Art

Ventilation is very important for human health and the quality of traveling in buses and similar public transportation vehicles. The rate of oxygen decreases and the rate of carbon dioxide and carbon monoxide increases in the blood after breathing impure air; especially in the cases in which sufficient ventilation is not ensured in crowded and closed areas. In these cases physical disturbances such as decrease in reflexes, exhaustion, lack of concentration, headache, neck pain, and backache occur. The air dried by the air conditioner leads to searing and irritation in the eyes.

In later stages breathing problems and difficulty in breathe may occur.

When the problems stated above happen in public transportation vehicles, besides threatening the passenger health, they may also lead to accidents by negatively affecting the driver of the vehicle. Therefore, ventilation in buses and similar public transportation vehicles is very important for human health; and it is a factor directly affecting the quality and safety of travelling.

In the present applications, ventilation in buses and similar public transportation vehicles is ensured by the method of absorption of impure air from closed area with the vacuum effect created by a fan, which is driven by an electric motor .

The electric motor, fans and electrical installation used for ventilation system in buses and similar public transportation vehicles is an expensive solution for ventilation. The possible failures that may occur in the ventilation unit cause maintenance problems since the system is in a place which is difficult to reach. Furthermore, because of the moving units of the system, the ventilation process takes place noisily. Thus, the quality of traveling decreases with the noise pollution.

Whereas in some of the present applications, for example in some local buses, there is no ventilation unit because of the disadvantages stated above. In these types of vehicles ventilation is carried out by opening windows and ventilation hatches placed on the ceiling of the vehicles. Opening windows or ventilation hatches may provide ventilation of the inside of the vehicle but with the air flowing in high sounds will enter the vehicle at the same time. With the noise of motor, wheels and traffic, the turbulence formed outside the vehicle causes exhaust gas enter the vehicle. Therefore this method is not a healthy ventilation method. Furthermore, fuel consumption and noise pollution will increase since the aerodynamic structure of the vehicle will be degenerated by opening windows or ventilation hatches.

Ventilation techniques in buses and similar public

transportation vehicles have been subject for many patents. The patent with the number of GB 289587 can be given as an example. In this patent, the principle used is; obtaining a zone with a low pressure due to the increased speed of the air flow in that zone, which is obtained by the flow of air through a narrowing section of a channel in order to provide ventilation by the help of the pressure difference which is formed due to the speed of the vehicle. The patents with the number of US 1487507, US 1518319, US 4522145 can be regarded as an example for ventilation units obtained with the use of this principle.

All of these patents are related with the ventilation system which depends on the principle of pressure difference occurring due to the speed of the vehicle. In all of these patents channels with a narrowing section is used in order to increase the speed of the air flow. Low pressure zone forms inside the channel and by the vacuum effect, it flows out of the channel together with the internal air of the vehicle.

Since both of the ends of the channel applied on the vehicle are open, these may be blocked due to various reasons. Birds, insects or various objects that might enter the channel may block the channel and break its functioning. In case that the channel is partly or completely blocked, there will be no air flow so that no pressure difference will be formed and therefore the air inside the vehicle can not be discharged. Furthermore, since the blockage of the channel will prevent the air flow while the vehicle is in motion, it will increase the air resistance and spoil the aerodynamics of the vehicle.

By formation of low pressure zone and mixing the discharged

air and external air inside the channel, external weather conditions may affect the internal air of the vehicle. This situation makes it difficult to keep the internal temperature of the vehicle at the desired values. Furthermore, since this situation can not prevent the entrance of the external noise inside the vehicle, it will not be a solution to noise pollution.

The solution to the problem of blockage of the channel in these patents have been a subject of invention for the patent with the number EP 1008477. By the help of the filter that is placed at the entrance of the channel, prevention of the blockage of the channel is aimed. However this solution has an effect of reducing the pressure difference which is desired to be formed, and also it will affect the aerodynamics of the vehicle negatively.

Description of the Invention

Purpose of this invention is to ensure the ventilation of bus and similar public transportation vehicles by means of the low pressure zone that is formed at the outer part of the vehicle ceiling due to the principle of pressure difference formed by the help of the vehicle speed, and unlike present applications, without using electrical energy.

This discharge system, which executes the discharge of the impure air inside the vehicle by the use of pressure difference, is composed of at least one hatch (3) that is opened automatically with the pressure difference, holders

(4) that prevent the hatches from turning upside down, sets

(2) preventing undesired objects from entering the vehicle that may enter from the hatches and body of the

ventilation unit (1) that has the appropriate form to increase the pressure difference to maximum level .

While the vehicle is in motion, the air flow that occur against the direction of motion forms low pressure zone at the backside of the ventilation unit (1) which is plain and on the outer side of the vehicle ceiling. The pressure of the air inside the vehicle is greater than the pressure at this zone. Therefore the air inside the vehicle will move towards the low pressure zone. Since air flow has ascending characteristic at low pressures, internal impure air of the vehicle will be discharged by the help of this pressure difference.

Body of the ventilation unit (1) is made in the form that will bring the pressure difference to maximum level . This part is made in the curvature form in order to increase the air flow speed as shown in figure 1, so it ensures the increase of the pressure difference, and therefore it ensures the increase of the flow rate of the impure air to be discharged with the increasing vacuum effect.

The sets (2) placed on the ventilation unit execute the function of interception and discharge of undesired materials that may enter from outside of the vehicle such as water, dust, particles etc.

The hatches (3) that are opened automatically with the pressure difference are closed during the backward motion of the vehicle or when the vehicle is immobile in order not to have back flow inwards the vehicle. In order to prevent the hatches (3) turn upside down, one holder (4) is used for each

hatch .

Since the discharge of the impure air inside the vehicle through the natural flow created by the pressure difference due to the vehicle speed doesn't include electrical installation, motor, fan etc. parts, its price is low and it can always be used at open position. Furthermore, since it is not composed of parts such as fan and electric motor, the ventilation system works silently. Therefore during travelling, the noise pollution that occur due to the operation of the ventilation unit will be removed.

Since the low pressure zone that is formed due to vehicle speed occurs outside of the vehicle, external weather conditions do not affect inside of the vehicle. Furthermore, by means of the sets and hatches (3) that is opened only from one side by means of the holders (4) , external weather or any other object is not permitted to enter the vehicle.

Clean and fresh air is moved inside the vehicle by the force from outside of the vehicle by opening ventilation valves. Fresh air entrance into the vehicle is assured independent of impure air discharge system.

With the use of the impure air discharge system for vehicles that are made by using pressure difference due to vehicle speed; it is purposed to provide economy despite it is always used in open position, remove internal noise arising from the ventilation system, and minimize the maintenance expenses.

Description of the Drawing's

The description of the drawings related with the invention are as follows:

Figure 1 : Impure air discharge system for vehicles in which pressure difference due to vehicle speed is used

References

1. Body of ventilation unit

2. Sets preventing entrance of undesired objects

3. Hatches that is opened automatically by pressure difference

4. Holders that prevent hatches from turning upside down