WO2004052702A1

WO2004052702A1 - Windshield providing apparatus for vehicles

Info

Publication number: WO2004052702A1
Application number: PCT/KR2003/002715
Authority: WO
Inventors: Goo Soon Kang; Hyung Jin Sung; Young Soo Park
Original assignee: Korea Advanced Institute Of Science And Technology
Priority date: 2002-12-12
Filing date: 2003-12-11
Publication date: 2004-06-24
Also published as: AU2003302916A1

Abstract

There is provided a windshield-window air-film providing apparatus for a vehicle, and more specifically, a windshield-window air-film providing apparatus for a vehicle capable of maximizing operations and effects of the exiting wipers of the vehicle such as cars, airplanes, and ships and preventing contaminants from being attached on the windshield window by spraying a strong jet stream on the windshield window. The windshield-window air-film providing apparatus forming an air-film made of high-velocity air flow on a windshield window of a vehicle, includes: a compressor for generating high-pressure air, a plurality of sprayers for receiving the high-pressure air and spraying jet streams, and a blowing pipe for feeding the compressed high-pressure air of the compressor to the plurality of sprayers.

Description

WINDSHIELD PROVIDING APPARATUS FOR VEHICLES

TECHNICAL FIELD The present invention relates to a windshield-window air-film providing apparatus for a vehicle, and more specifically, to a windshield- window air-film providing apparatus for a vehicle capable of maximizing operations and effects of the exiting wipers of the vehicle such as cars, airplanes, and ships and preventing contaminants from being attached on the windshield window by spraying a strong jet stream on the windshield window.

BACKGROUND ART

In general, a car comprises wipers provided on its bonnet in order to remove contaminants on its windshield window. However, it is inconvenient that a washer solution, that is, a lubricant having a high viscosity, is necessarily provided between the wipers and the windshield window. In addition, there is a problem that the washer solution used to remove the contaminants leaves specks on the windshield window. In order to solve the conventional problem, an apparatus for forming an air-film by spraying a compressed air on the windshield window of the vehicle is proposed.

In the conventional air-film providing apparatus, there are provided nozzles on the bonnet of the vehicle in order to spray the compressed air on the windshield window. However, in the construction of the apparatus, the relationship between the wipers and the apparatus is overlooked. Therefore, when the air-film providing apparatus is used together with the exiting wipers, the air flow of the vehicle may be impeded, and the apparatus may be not useful.

In addition, in order to prevent dew or frost from being generated due to temperature difference between the inside and outside of the vehicle, in the conventional air-film providing apparatus, a heater supplies heat to the compressor itself to form a thermal insulating air-film. However, in the construction of the apparatus, there is a problem that overheat and vapor may occur within the compressor.

In addition, another apparatus for providing a high-temperature windshield window by supply vented gas to the compressor is proposed. However, there is another problem that the apparatus has to comprise an additional filter unit.

SUMMARY OF THE INVENTION

In order to solve the above mentioned problems, an object of the present invention is to provide an effective air-film on a windshield window by cooperating an air-film providing apparatus with wipers.

In addition, another object of the present invention is to provide an air film providing apparatus to a side of a wiper capable of sensing rotations of the wiper and selectively spraying high-pressure air.

In addition, still another object of the present invention is to form an effective, practical high-temperature thermal insulating air-film by mixing high-pressure air generated by a compressor and hot wind generated from a heat source by using a valve to blowing pipe.

According to an aspect of the present invention, there is provided a windshield-window air-film providing apparatus for a vehicle, the apparatus forming an air-film made of high-velocity air flow on a windshield window of a vehicle, the apparatus comprising: a compressor for generating high-pressure air; a plurality of sprayers for receiving the high-pressure air and spraying jet streams; and a blowing pipe for feeding the compressed high-pressure air of the compressor to the plurality of sprayers, wherein each of the sprayers comprises: an inlet for receiving the high-pressure air through the blowing pipe; a slot-shaped chamber having a plurality of side walls; and an outlet for emitting the high- pressures air generated by the compressor with a spraying angle and a spraying velocity, and a spraying quantity of air flow, wherein the spraying angle is set so that the jet stream sprayed on the windshield window of the vehicle can not change the air flow of the vehicle, and wherein the spraying velocity is set so that the velocity of the jet stream can be higher than that of the vehicle, and wherein the spraying quantity is set to correspond to the spraying angle and velocity.

In addition, it is preferable that the air is replaced with a fluid. In addition, it is preferable that the adjacent outlets are separated by the maximum horizontal distance corresponding to the width of the jet steams in case of the velocity of the jet streams sprayed by the plurality of the sprayers being higher than that of the vehicle.

In addition, it is preferable that the number of the sprayers is a value of the width of the windshield window divided by the maximum horizontal distance. According to another aspect of the present invention, there is provided a windshield-window air-film providing apparatus for a vehicle, the apparatus forming an air-film made of high-velocity air flow on a windshield window of a vehicle, the apparatus comprising: a compressor for generating high-pressure air; a plurality of sprayers for receiving the high-pressure air and spraying jet streams; and a blowing pipe for feeding the compressed high-pressure air of the compressor to the plurality of sprayers, wherein the apparatus further comprises a first control unit for selectively feeding the high-pressure air generated by the compressor to a bonnet and a wiper of the vehicle, wherein each of the sprayers comprises: a bonnet spray unit for spraying a jet stream on the windshield window by using the high-pressure air fed to the bonnet; and a wiper spray unit for spraying a jet stream on the windshield window by using the high- pressure air fed to the bonnet at the time of the wiper being operated.

In addition, it is preferable that the apparatus further comprises a hot wind control unit for adding the hot wind supplied by a heat source to the high-pressure air generated by the compressor in accordance with functions of the windshield-window air- film.

In addition, it is preferable that the first control unit or the hot airflow control unit is constructed with a solenoid valve. In addition, it is preferable that the first control unit intermittently feeds the high-pressure air to a washer solution emitting opening, thereby preventing the washer solution emitting opening from being clogged.

In addition, it is preferable that each of the bonnet sprayers comprises a slot-shaped outlet, the slot-shaped outlet for emitting the high-pressures air generated by the compressor with a spraying angle and a spraying velocity, and a spraying quantity of air flow, wherein the spraying angle is set so that the jet stream sprayed on the windshield window of the vehicle can not change the air flow of the vehicle, and wherein the spraying velocity is set so that the velocity of the jet stream can be higher than that of the vehicle, and wherein the spraying quantity is set to correspond to the spraying angle and velocity.

According to still another aspect of the present invention, there is provided a windshield-window air-film providing apparatus for a vehicle, the apparatus forming an air- film made of high- velocity air flow on a windshield window of a vehicle, the apparatus comprising: a compressor for generating high-pressure air; a wiper sprayers for receiving the high- pressure air and spraying jet streams; and a blowing pipe for feeding the compressed high-pressure air of the compressor to the wiper sprayers, wherein the apparatus further comprises a. second control unit for selectively feeding the high-pressure air generated by the compressor to both sides of the wiper in accordance with rotational directions of the wiper, wherein each of the wiper sprayers comprises: a wiper arm enclosing some portion of the blowing pipe for feeding the compressed high-pressure air; a wiper main body being connected to the wiper arm; and a sprayer enclosure being attached to the wiper main body, the sprayer enclosure for selectively spraying the high-pressure air fed by the blowing pipe in accordance with the rotational directions of the wiper main body under the control of the second control unit.

It is preferable that the sprayer enclosure comprises: two parallel conduits connected to the blowing pipe, the two parallel conduits feeding the high-pressure air to left and right sides of the wiper main body, respectively; and a plurality of air-emitting nozzles protruded from each of parallel conduits, the plurality of the air-emitting nozzles spraying the jet streams by using the high-pressure air.

In addition, it is preferable that the air-emitting nozzles have different diameters according to the difference between the quantities of the supplied high-pressure air flow, and the shape of the cross section of the air-emitting nozzle is elliptic.

In addition, it is preferable that the blowing pipe comprises two passages for feeding the high-pressure air to the two parallel conduits.

In addition, it is preferable that the apparatus further comprises a sensor for sensing rotational directions of the wiper main body. In addition, it is preferable that the second control unit is constructed with a solenoid valve.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other objects, advantages and features of the present invention will become apparent from the following description of preferred embodiments given in conjunction with the accompanying drawings, in which:

FIG. 1 is a block diagram of a windshield-window air-film providing apparatus according to an embodiment of the present invention; FIG. 2A is a view illustrating a usage of a bonnet spray unit according to an embodiment of the present invention;

FIG. 2B is a conceptual view of a "jet stream" sprayed by a bonnet sprayer according to the embodiment of the present invention; FIG. 2C is a detailed view of a bonnet sprayer according to the embodiment of the present invention;

FIG. 2D is an enlarged view of a nozzle of the bonnet sprayer according to the embodiment of the present invention;

FIG. 2E is a view illustrating distribution of the "jet stream" sprayed by the bonnet sprayer according to the embodiment of the present invention;

FIG. 2F is a graph of velocity distribution of the dimensionless jet stream with respect to the variable "a" in Equation 1 with x = 0.45 in accordance with the embodiment of the present invention; FIG. 2G is a schematic diagram illustrating a jet stream and its hitting region of the windshield window in accordance with the present invention;

FIG. 3 is a view illustrating an experiment for performance of the jet stream of the bonnet sprayer according to the present invention; FIG. 4 is a graph illustrating an average velocity of the air flow at the central portion of the sloped surface on which the jet stream is sprayed by the bonnet sprayer according to the present invention;

FIG. 5A is a graph of the average velocity at the lower portion of the sloped surface on which the jet stream is sprayed according to the experiment of FIG. 3;

FIG. 5B is a graph of the average velocity at the upper portion of the sloped surface on which the jet stream is sprayed according to the experiment of FIG. 3; FIG. 5C is a view illustrating an iso-intensity distribution of the average velocity of the air flow on the sloped surface on which the jet stream is sprayed according to the experiment of FIG. 3 in case of U = 0.1 ;

FIG. 5D is a view illustrating an iso-intensity distribution of the average velocity of the air flow on the sloped surface on which the jet stream is sprayed according to the experiment of FIG. 3 in case of U^* = 0.2;

FIG. 6 is a graph illustrating a turbulence kinetic energy having double peaks in the experiment of the present invention; FIG. 7A is a view illustrating a usage of a wiper spray unit according to an embodiment of the present invention;

FIG. 7B is a detailed view of a wiper sprayer according to the embodiment of the present invention;

FIG. 8 is view illustrating temperature distributions inside and outside a vehicle in winter when the air conditioner is operated and in summer when the heater is operated; and

FIG. 9 is a conceptual view according to still another embodiment of the present invention.

BEST MODE FOR CARRYING OUT THE INVENTION

Now, the preferred embodiments according to the present invention will be described in details with reference to the accompanying drawings. FIG. 1 is a block diagram of a windshield-window air-film providing apparatus according to an embodiment of the present invention. The term "air-film" means a state that air flow or air stream cover a windshield window of a vehicle.

Referring to FIG. 1 , the air film providing apparatus according to the present invention comprises a compressor 10 for generating high- pressure air, a first control unit 11 for selectively feeding the high- pressure air to a bonnet or a wiper of a vehicle, a bonnet spray unit 12 for spraying a jet stream on the windshield window by using the high- pressure air fed to the bonnet, and a wiper spray unit 14 for spraying a jet stream on the windshield window by using the high-pressure air fed to the bonnet at the time of the wiper being operated, a hot wind control unit 16 for adding the hot wind supplied by a heat source 15 to the high-pressure air generated by the compressor in accordance with functions of the windshield-window air-film, and blowing pipe for connecting the aforementioned components. The compressor 10 includes electrical-type and belt-type compressors. The belt-type compressor has an advantage in that it is operated without an additional power source since a driving shaft of its compressing pump is connected to an engine power shaft with a belt. But it has a disadvantage in that the belt-type compressor can not be arbitrarily controlled since its rotation depends on the rotation of the engine. On the other hand, the electrical-type compressor has a disadvantage in that its compressing pump is operated with an additional power source, that is, an electrical motor. But it has an advantage in that the electrical motor of the electrical-type compressor can be easily controlled.

In addition, it is preferable that the windshield-window air-film apparatus may comprise a compressed air tank 10a inside or outside the compressor 10 to store and supply the high-pressure air generated by the compressor 10. By means of the compressed-air tank, it is possible to prevent the compressor from overloading and to suitably obtain the high- pressure air.

Since the volume of the air compressor tank 10a is relatively large and the performance of the recently-developed air compressor is increased, the compressed air tank 10a may be omitted.

The first control unit 11 determines to which of the bonnet spray unit 12 and the wiper spray unit 14 the high-pressure air is fed. Preferably, the first control unit 11 utilizes a solenoid valve. Preferably, the solenoid valve opens to the wiper spray unit 14 at the time of the wiper being operated and to the bonnet spray unit 12 at the time of the wiper not being operated.

The bonnet spray unit 12 has slot-shaped nozzles to spray the high- pressure air in order to form a wide width of an effective jet stream. The spraying angle is formed in order for the jet stream to be directed to the central portion of the windshield window. The slot-shaped nozzles will be described later.

The wiper spray unit 14 preferably comprises first and second wiper sprayers 14a and 14b to spray the jet stream to the left and right rotational directions of the wiper, respectively.

In addition, the windshield-window air-film apparatus preferably further comprises second control unit 13 in order to selectively supply the high-pressure air fed by the first control unit 11 to the first and second wiper sprayers 14a and 14b. Preferably, the second control unit 13 utilizes a solenoid valve.

The hot wind control unit 16 is used to spray high-pressure and high-temperature air. The hot wind control unit 16 injects the hot wind supplied from a heat source 15 into the blowing pipe connected to the compressed air tank 10a in order to mix the hot wind with the high- pressure air. The heat source 15 is preferably the engine where the engine heat is generated.

In the hot wind control unit 16, the hot wind generated by the heat source and the high-pressure air are mixed and the mixed air flow is used to form a thermal insulating air-film. In addition, instead of the hot wind control unit 16 for supplying the hot wind, a resistor coil can be used. By applying electrical current to the resistor coil wounded around the blowing pipe, the heat generated by the resistor coil is supplied to the high-pressure air flow, so that the thermal insulating air-film can be formed.

FIG. 2A is a view illustrating a usage of a bonnet spray unit according to an embodiment of the present invention. In the figure, the first and second control units 11 and 13, the wiper spray unit 14, and the hot wind control unit 16 of FIG. 1 are omitted. Referring to FIG. 2A, the windshield-window air-film providing apparatus related to the bonnet 110 comprises a compressor 210, a blowing pipe 220, and bonnet sprayers 230.

The compressor 210 generates high-pressure air flow used to form air- film. As described above, the compressor 210 includes electrical - type and belt-type compressors. As its related technique is improved, various types of compressors may be employed. In addition, instead of the air flow, other fluids may be used. In the specification, the air should be understood to be replaced with the other fluids.

The blowing pipe 220 connecting the compressor 210 and the bonnet sprayers 230 is used as a passage for feeding the air compressed by the compressor 210 to the plurality of the bonnet sprayers 230. The blowing pipe 200 uniformly feeds the compressed air to the bonnet sprayers 230 for the purpose of uniform spraying.

The bonnet sprayers 230 spray the compressed air fed from the compressor 210 through the blowing pipe 220 as a high-speed jet stream on the windshield window 120. It is preferable that the sprayed air flow conforms to the shape of the windshield window in order not to affect the surrounding air flow of the vehicle. In order to form an effective air-film on the windshield window, the air flow is sprayed at the higher velocity than the velocity at the time of no air sprayed on the windshield window. If the velocity and the quantity of the sprayed air flow are slow and small, respectively, the jet stream may not reach the windshield window and be absorbed in the existing flow. On the other hand, if the velocity or the quantity of the sprayed air flow is too rapid or much, respectively, the jet stream may not conform to the shape of the windshield window but hit the windshield window to change the existing air flow of the vehicle. As a result, noises may be generated and resistance may be increased. In order to form the effective air-film without changing the existing air flow of the vehicle, a spraying velocity V_{j et}, a spraying angle β, and spraying quantity are optimally set.

FIG. 2B is a conceptual view of a "jet stream" sprayed by a bonnet sprayer according to the embodiment of the present invention. The spraying quantity is adjusted by the spraying velocity and the hole diameter. Preferably, the spraying quantity is adjusted in order for the air-film to cover all the area of the windshield window under the optimal spraying condition. For this reason, firstly a spreading angle α of the jet stream is measured and then the width of the air flow sprayed from a single hole is calculated by using the spreading angle. After that, it is determined how many the flows having the calculated width are needed to cover all the area of the windshield window. And then, the number and interval of holes and are set. FIG. 2C is a detailed view of a bonnet sprayer according to the embodiment of the present invention.

The bonnet sprayer 230 of the present invention comprises an inlet

231 for receiving compressed air from the blowing pipe 220, a chamber

232 having four side walls PI , P2, P3, and P4, and an outlet for emitting the jet stream. In order to form symmetrical spraying, the outlet has various shapes for example, a round spraying opening or a circular jet opening. Preferably, the outlet has a slot-shaped spraying opening, as shown in FIG. 2C.

The wide jet stream is more preferable than the thick one in order to form the air- film. Even a few wide-spreading jet streams can provide an effective air-film on the windshield window of the vehicle. The use of the wide-spreading jet streams results in a minimal change of the design of the existing vehicle. And also, it enables to a small-capacity compressor to generate a required quantity of the compressed air. As described in FIG. 2C, the slot has a shape of a rectangle having a width t and a length L. The chamber 232 has a function of changing the circular air flow of the blowing pipe 220 into a slot-shaped jet stream. The inlet has a shape of a square. The chamber 232 is constructed to match with the shapes of the inlet and outlet, that is, square and slot, respectively, by an elongation and contraction shaping process.

The quantity of air flow of the bonnet sprayers 230 is to be smaller than the air flow around the vehicle. Therefore, the air flow generated by the high-pressure air spraying does not greatly affect the existing air flow except for the air flow of the windshield window.

FIG. 2D is an enlarged view of a nozzle of the bonnet sprayer according to the embodiment of the present invention.

As described above, the air flow is to be sprayed at the higher velocity than the velocity at the time of no jet stream on the windshield window. The spraying velocity and angle of the jet stream are defined depending on the shape of the nozzle. If the spraying angle is too wide, the spraying area is wide but the velocity is too slow. In order to obtain a high-velocity jet stream, the nozzle has a sharp shape.

FIG. 2E is a view illustrating distribution of the "jet stream" sprayed by the bonnet sprayer according to the embodiment of the present invention.

The jet stream has a rectangular distribution at the point of the slot-shaped outlet 233. As farther sprayed, the jet stream has a Gaussian distribution by its dispersion. A general jet stream has the Gaussian distribution having self similarity and can be represented by the following dimensionless variables.

Assuming that x and r is vertical and horizontal distance from the center of the outlet 233 of the jet stream to a given point, the jet stream is represented by the following Equation 1. [Equation 1]

U(x, r)/Uo = sech² (10.4r/(x+a))

Herein, "sech" denotes a hyperbolic secant, U(x, r) is a velocity of the jet stream at the point (x, r), U₀ is a velocity of the jet stream at its center, and the variable "a" is set by the shape of the jet stream.

The size of the windshield window of a typical medium-size passenger car is almost 1.3m x 0.90m (width x length). The most important portion of the windshield window during driving of the vehicle is its central portion. Therefore, the variable "x" is set to be 0.45m. In general, the variable "a" has a value between 0.001 and 0.05. The variable "a" does not more affect the jet stream than the variable "x" . In case of a = 0, the jet stream is ideal.

FIG. 2F is a graph of velocity distribution of the dimensionless jet stream with respect to the variable "a" in Equation 1 with x = 0.45 in accordance with the embodiment of the present invention.

In case of a = 0, the velocity distribution of the dimensionless jet stream is shown by the lower curve in FIG. 2F and represented by the following Equation 2. [Equation 2]

U(x, r)/Uo = sech² (23.1 lr)

Herein, a = 0 and x = 0.45.

Next, in case of a = 0.05, the velocity distribution of the dimensionless jet stream is shown by the upper curve in FIG. 2F and represented by the following Equation 3.

[Equation 3]

U(x, r)/Uo = sech² (20.8r) Herein, a = 0.05 and x = 0.45.

As the points are far from the jet slot, that is, as the variable "x" is increased, the value l/(x+a) is approximately the same as the value 1/x. Therefore, the jet stream velocity distribution is not largely different depending on the variable "a". The jet stream is analyzed by using the two equations. It is assumed that it rains or snows, the wiper is used, and the velocity of the vehicle is 72km/h or 20m/s. In order to form the air- film on the windshield window by using the jet stream sprayed by the outlet 233, the velocity of the jet stream at the hitting region, that is, x = 0.45m, must be higher than the velocity of the vehicle, that is, 20m/s. If the desired velocity of the jet stream is higher than the velocity of the vehicle by 50%, the velocity of the jet stream is 30m/s. Assuming that the maximum velocity U₀ of the jet stream at the point of x = 0.45m is set to be 40m/s. the points corresponding to the U(x, r) = 30m/s is found by using the above equations. Referring to FIG. 2F and the above equations, in case of a = 0 and r = 0.0238m, U(x, r) = 30m/s, and in case of a = 0.05 and r = 0.0264m, U(x, r) = 30m/s. Accordingly, the width of the jet stream corresponding to 2r is 0.0476m in case of a = 0, and 0.0528m in case of a = 0.05. The maximum air flow interval corresponding the velocity of the jet stream, 30m/s is 0.0476m in case of a= 0, and 0.0528m in case of a=0.05.

The boundary of the jet stream is defined by using the distance between the points having velocities being 10% of the velocity of the center of the jet stream. Since the velocity of the jet stream is Uo = 40 m/s, the points having velocities being 4m/s constitute the boundary. Total quantity of the flow sprayed by the outlet 233 is approximately calculated to comprise the air flow enclosed by the boundary. Since U(x, r)/Uo = 0.1 , the horizontal distance "r" is calculated by using FIG. 2F. As a result, r = 0.078m in case of a = 0, and r = 0.087m in case of a = 0. The average velocity of the jet stream is obtained by integrating the aforementioned equations.

Firstly, in case of a = 0, integration is made by using Equation 2, [Equation 4] (dimensionless total quantity of flow) = J₀° ⁰⁷⁸⁰

= Jo^{0 078}sech²(23.11r)dr = 0.04105

Next, in case of a = 0.05, integration is made by using Equation 3. [Equation 5] (dimensionless total quantity of flow) = J^" ₀° ⁰⁸⁷⁰

= j o° ⁰⁸⁷sech²(20.8r)dr = 0.045

The average velocity U_mean is obtained by multiplying the U₀ to the dimensionless total quantity of flow and dividing the resulting value with the width of the jet stream.

In case of a = 0, U_mean = U₀ x (total quantity of flow)/ (width of the jet stream) = 40 x 0.04105 /0.078 = 21.05m/s, and in case of a = 0.05, Umean = 40x0.045/0.087 = 20.69m/s. In order to spray such a quantity of the air flow, spraying velocity of the jet stream at the slot, that is, at x = 0 needs to be 109.5m/s in case of a = 0 and 125m/s in case of a = 0.05.

The aforementioned results are listed in the following table. The case of a = 0 corresponds to the ideal jet stream. The practical air- film is designed by using the case of a = 0.05.

[Table 1]

In order to extend the width of the jet stream, the slot-shaped outlet is used. The size of the slot having the same area as a circular outlet having a diameter of 6mm is 30mm x 1mm (width x thickness). In case of using the slot with a width of 30mm and a spraying velocity of 125 m/s, the jet stream has its width of 52.8mm and its velocity of more than 30m/s at x = 0.45m, that is, at the hitting region on the windshield window. Accordingly, the outlet interval can be set to be 52.8mm. Since the width of the windshield window is about 1 ,300mm, the number of the outlets 233 is preferably about 24 in order to form the air-film on the windshield window.

FIG. 2G is a schematic diagram illustrating a jet stream and its hitting region of the windshield window in accordance with the present invention.

It is preferable that the sprayed jet stream reaches the central portion of the windshield window which is the most important portion during driving of the vehicle.

FIG. 3 is a view illustrating an experiment for performance of the jet stream of the bonnet sprayer according to the present invention.

In order to simulate the same air flow as that at the time of the vehicle running, a blowing wind 330 is flown into an elongated duct in which a sloped surface 310 having a ^' sloped angle of 35° is provided. The sloped surface corresponds to the windshield window. A free air flow is formed in the elongated duct by using the blowing wind 330. In order to simulate the slot outlet 233 of the bonnet sprayer 230, a rectangular slot is formed at the predetermined distance from the bottom end of the slope surface. A high-pressure jet stream generated by an experimental compressor 340 is sprayed through the slot 340 toward the central portion of the sloped surface 310.

The sloped angle of 35° and the central portion are selected in consideration of the sloped angle of the windshield window of a general passenger vehicle and the most important portion in the driver's viewing. FIG. 4 is a graph illustrating an average velocity of the air flow at the central portion of the sloped surface on which the jet stream is sprayed by the bonnet sprayer according to the present invention.

[Table 2]

Table 2 illustrates air flow at the central portion, that is, v = 3/6, of the sloped surface having a sloped angle of 35° affected by the jet stream of the bonnet sprayer.

The variables in Table 1 are as follows. (dimensionless velocity of the free air flow): U^* = U/U_jet ,

Herein, U is U(a velocity of the free air flow = velocity of the vehicle), and Uj_et is Uj_et (a spraying velocity of the jet stream = 100 m/s). (dimensionless measured velocity): v^* = v/U

Herein, v is v(an average velocity of the air flow at the sloped surface added by the jet stream), and U is U(a velocity of the free air flow = velocity of the vehicle).

(dimensionless y-directional height): y = y/y₀

Herein, y is y(a vertical height from the sloped surface), and y₀ is y₀(the lowest measurable vertical height measured from the sloped surface). (dimensionless z-directional width): z = z/z₀

Herein z is z(a width of the dispersed jet stream), and z₀ is z₀(reference width of the jet stream = 10mm).

In the above equations, the variable v _max is a maximum value of z at the central portion of the sloped surface after the jet stream being sprayed. The variable y _max is a maximum value of y corresponding to the value of v _max at the central portion of the sloped surface after the jet stream being sprayed. The variable z _Wj_dt s a width of z corresponding to the value of v being higher than U∞ at the central portion of the sloped surface after the jet stream being sprayed.

Referring to FIG. 1 and Table 1 , it can be understood that the average velocity of the air flow v is increased after the jet stream is sprayed. Accordingly, the increased average velocity of the air flow on the windshield window makes an effect of removing the contaminants on the windshield window.

In addition, as the dimensionless velocity of the free air flow U is lowered, the dimensionless measured velocity v _ma is increased and the width z wi th of the air flow is widened.

The position at which the spraying velocity is most increased is the position of y = 1 nearest the sloped surface in all the experiments. Accordingly, in order to obtained highest average velocity of the air flow by the jet stream, the velocity at the nearest point of the windshield window of the vehicle. Therefore, it is most preferable that the jet stream is rapidly sprayed at the lower value of y. FIGs. 5A and 5B are graphs of the average velocities at the lower portion (x = 1/6) and the upper portion (x = 5/6) of the sloped surface on which the jet stream is sprayed. FIGs. 5C and 5D are views illustrating iso-intensity distributions of the average velocities of the air flow on the sloped surface on which the jet stream is sprayed in case of U = 0.1 and U = 0.2, respectively.

As shown in FIGs. 5A and 5B, if the value of U is increased, that is, if the free velocity of the air flow is higher, the effect of the jet stream is lowered and the width of the jet stream is narrowed (see the black region 500 in the figures).

Referring to FIGs. 5A to 5D, the large value of x* means a long distance from the bonnet sprayer to the jet stream. Accordingly, the shorter the distance is, the larger the effect of the jet stream is. Therefore, it is preferable that the bonnet sprayer is constructed at a nearer position from the lower portion of the windshield window of the vehicle. The large value of U* means a higher velocity of the vehicle. In general, the higher the velocity of the vehicle is, the smaller the effect of the jet stream is. Therefore, it is preferable to construct a jet stream velocity adjusting apparatus for increasing and reducing the velocity of the jet stream at the lower and higher velocities of the vehicle, respectively, in order to reduce energy consumption and prevent overloading of the engine.

FIG. 6 is a graph illustrating a turbulence kinetic energy having double peaks in the experiment of the present invention. The phenomenon that the turbulence kinetic energy has the double peaks is generally observed in a jet stream. Accordingly, the validity of the experiment of the present invention can be verified by the double peaks observed in FIG. 6. FIG. 7A is a view illustrating a usage of a wiper spray unit according to an embodiment of the present invention. FIG. 7B is a detailed view of a wiper sprayer according to the embodiment of the present invention.

In FIG. 7 A, the first control unit 11, the bonnet spray unit 12, and the hot wind control unit 16 of FIG. 1 are omitted. The first and second wiper spray units correspond to the left and right parallel conduits.

Referring to FIGs. 7A and 7B, the windshield-window air-film providing apparatus with respect to the wipers according to the present invention comprises a compressor 210, a blowing pipe 220, wiper sprayers 700, and a second control unit 740.

The compressor 210 has the same construction as that of FIG. 3, so its detailed description is omitted.

The blowing pipe 220 connects the compressor 210 and the second control unit 740. The high-pressure air which is generated by the compressor 220 is fed to the first control unit (not shown) and then fed to the second control unit 740 through the blowing pipe 220. In addition, through the blowing pipe 220, the air is fed from the second control unit 740 to the wiper sprayers 700. The blowing pipe 220 uniformly feeds the compressed air to the wiper sprayers 700 for the purpose of uniform spraying at the spraying nozzles of the wiper sprayers 700.

Each of the wiper sprayers 700 comprises a sprayer enclosure 720 attached to the wiper main body 710. The sprayer enclosure 720 is connected to the blowing pipe 220 which is inserted and extended along the wiper arm 730. The sprayer enclosure 720 comprises left and right parallel conduits 721 (721a and 721b) which are connected to the blowing pipe and extended in the left and right vertical direction of the wiper main body 710 and air-emitting nozzles 722 which are protruded from the left and right parallel conduits 721 (721a and 721b). The blowing pipe 220 is provided along the wiper arm 730 to supply the high-pressure air to the parallel conduits 721. In order to achieve the function of the second control unit 740, it is preferable that the two passages are separately provided inside the blowing pipe 220 and connected to the corresponding parallel conduits, as shown in FIG. 2B. The blowing pipe may be connected to the interconnecting portion between the parallel conduits 721. More preferably, the respective blowing pipes are connected to end portions of the parallel conduits 721 in order to uniformly supply the high-pressure air. The air-emitting nozzles 722 have different diameters according to the difference between the quantities of the supplied high-pressure air flow. The shape of the cross section of the air-emitting nozzle is preferably elliptic in order to effectively spray the high-pressure air on the suitable area. In addition, the wiper blade is attached to the upper portion of the sprayer enclosure 720. The second control unit 740 has a function of selecting one of the left and right parallel conduits 721 to spray the jet stream in only the rotational direction of the wiper of the vehicle. Preferably, the second control unit 740 utilizes solenoid valves. In other words, in case of the wiper rotating in the left, the solenoid valve to the left parallel conduit 721b is opened and the solenoid valve to the right parallel conduit 721a is closed. As a result, the jet stream is sprayed by air-emittiήg nozzles connected to the left parallel conduit 721b. On the other hand, in case of the wiper rotating to the right, the solenoid valve to the right parallel conduit 721 a is opened and the solenoid valve to the left parallel conduit 721b is closed. As a result, the jet stream is sprayed by the air-emitting nozzles connected to the right parallel conduit 721 a.

A control signal of the second control unit 740 is output by the operation of limit switches when the wiper reaches the position corresponding to the both end angles of the wiper rotation. In case of the wiper being operated by two motors, it is preferable that the left and right motor driving signals are used as the control signals of the second control unit 740.

FIG. 8 is view illustrating temperature distributions inside and outside a vehicle in winter when the air conditioner is operated and in summer when the heater is operated.

Dew, small drops of water, is generated by liquidation of oversaturated water vapor when the temperature of the water vapor is lowered below the dew temperature. When the inside temperature of the vehicle is lower than the window temperature, the temperature of the air near the window is higher than the inside temperature of the vehicle, so that saturated vapor quantity is increased and the dew is not generated. This is the method of removing the dew by using the air conditioner in summer. By the operation of the air conditioner, the inside temperature of the vehicle is lower than the outside temperature and the window temperature, so that the dew can be removed. In winter, by the operation of the heater, the inside temperature of the vehicle is higher than the outside temperature, and thus the window temperature is lower than the inside temperature. The temperature of the water vapor contacting the lower temperature window is lowered below its dew point temperature, so that the dew is generated by the liquidation of the wafer vapor contacting the lower temperature window. Therefore, the window temperature of the vehicle must be increased in order to remove the dew. If the high- temperature air is sprayed on the windshield window, the window temperature is increased to remove the dew. At this time, the higher the temperature of the sprayed air, the more effectively the dew is removed.

Accordingly, the windshield-window air-film providing apparatus according to the present invention preferably comprises an additional air heating unit (not shown) for spraying the high-temperature air flow outside the windshield window. Otherwise, the windshield-window air- film providing apparatus according to the present invention may spray the high-temperature air flow heated by the hot wind control unit 16 by using the heat generated in the vehicle itself. In another preferred embodiment of the present invention, the windshield-window air-film providing apparatus according to the present invention is disposed near the side mirrors in order to effectively remove water drops on the mirror when it rains. In still another preferred embodiment of the present invention, the windshield-window air-film providing apparatus according to the present invention is disposed near the back window of the vehicle in order to remove dew or water drops on the back window.

Referring to FIG. 9, the air-film providing apparatus 910 of the present invention is provided at the rear portion of the ceiling 130 of the vehicle 100 to spray a high- velocity jet stream 920 along the back window 140. The jet stream facilitates to streamline the rear air flow of the vehicle, so that the separation can be delayed and separation air bubbles can be reduced. Therefore, the fictional resistance can be reduced and thus the fuel efficiency can be improved.

Up to now, the present invention is mainly described to be adapted to cars. However, the present invention can be adapted to various vehicles such as ships and airplanes having the windshield-window.

Since the ship has windows in its engine room and steering house and the airplane has windows in its pilot house and passenger cabin, the air-film providing apparatus can be suitably adapted and modified to the ship and airplane

The air-film providing apparatus may be adapted to have various shapes and installation intervals and to spray jet streams with various velocities according to the velocities and shapes of the vehicles and the sizes of the windows.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it will be understood by those of ordinary skill in the art that various changes in form and details may be made therein without departing from the spirit and scope of the present invention. The scope of the present invention should be defined not by the above described embodiments but by the following claims and its equivalences.

INDUSTRIAL AVAILABILITY According to the present invention, since the wiper can be cooperated with the air-film providing apparatus in order not to prevent the air flow on the windshield window, it is possible to provide an efficient air-film providing apparatus

In addition, according to the present invention, since the wiper sprayers added to the wipers can selectively spray the high-pressure air flow in accordance with the rotational directions of the wipers, it is possible to reduce resistance between the wipers and the windshield window and effectively remove contaminants on the windshield window.

In addition, according to the present invention, since the high- pressure air flow from the compressor and the high-temperature air flow can be mixed through the blowing pipes and fed to the sprayers, it is possible to form a thermal insulating air-film by using a common compressor. In addition, according to the present invention, it is possible to provide a jet stream having the spraying quantity, velocity, and angle suitable for an effective air-film providing apparatus by using a slot- shaped sprayer.

In addition, according to the present invention, it is possible to prevent damage of the windshield window due to particles, for example, sands by using the air-film during high speed driving.

In addition, according to the present invention, it is possible to maximize performance of the wiper when it rains and to clarify the driver's viewing, and thus to prevent an accident in advance.

Claims

WHAT IS CLAIMED IS:

1. A windshield-window air-film providing apparatus for a vehicle, the apparatus forming an air-film made of high-velocity air flow on a windshield window of a vehicle, the apparatus comprising: a compressor for generating high-pressure air; a plurality of sprayers for receiving the high-pressure air and spraying jet streams; and a blowing pipe for feeding the compressed high-pressure air of the compressor to the plurality of sprayers, wherein each of the sprayers comprises: an inlet for receiving the high-pressure air through the blowing pipe; a slot-shaped chamber having a plurality of side walls; and an outlet for emitting the high-pressures air generated by the compressor with a spraying angle and a spraying velocity, and a spraying quantity of air flow, wherein the spraying angle is set so that the jet stream sprayed on the windshield window of the vehicle can not change the air flow of the vehicle, and wherein the spraying velocity is set so that the velocity of the jet stream can be higher than that of the vehicle, and wherein the spraying quantity is set to correspond to the spraying angle and velocity.

2. The windshield- indow air-film providing apparatus according to claim 1 , wherein the air is replaced with a fluid.

3. The windshield-window air-film providing apparatus according to claim 1 , wherein the adjacent outlets are separated by the maximum horizontal distance corresponding to the width of the jet steams in case of the velocity of the jet streams sprayed by the plurality of the sprayers being higher than that of the vehicle.

4. The windshield-window air-film providing apparatus according to claim 1 , wherein the number of the sprayers is a value of the width of the windshield window divided by the maximum horizontal distance.

5. A windshield- window air-film providing apparatus for a vehicle, the apparatus forming an air-film made of high-velocity air flow on a windshield window of a vehicle, the apparatus comprising: a compressor for generating high-pressure air; a plurality of sprayers for receiving the high-pressure air and spraying jet streams; and a blowing pipe for feeding the compressed high-pressure air of the compressor to the plurality of sprayers, wherein the apparatus further comprises a first control unit for selectively feeding the high-pressure air generated by the compressor to a bonnet and a wiper of the vehicle, and wherein each of the sprayers comprises: a bonnet spray unit for spraying a jet stream on the windshield window by using the high-pressure air fed to the bonnet, and a wiper spray unit for spraying a jet stream on the windshield window by using the high-pressure air fed to the bonnet at the time of the wiper being operated.

6. The windshield-window air-film providing apparatus according to claim 5, wherein the apparatus further comprises a hot wind control unit for adding the hot wind supplied by a heat source to the high-pressure air generated by the compressor in accordance with functions of the windshield-window air-film.

7. The windshield-window air-film providing apparatus for a vehicle according to claim 5, wherein the apparatus further comprises a resistor coil wounded around the blowing pipe, the resistor coil supplying heat to the high-pressure air flow generated by the compressor and fed to the sprayer in accordance the functions of the windshield-window air-film.

8. The windshield- window air- film providing apparatus for a vehicle according to claim 5 or 6, wherein the first control unit or the hot air-flow control unit is constructed with a solenoid valve.

9. The windshield-window air-film providing apparatus for a vehicle according to claim 5, wherein the first control unit intermittently feeds the high-pressure air to a washer solution emitting opening, thereby preventing the washer solution emitting opening from being clogged.

10. The windshield-window air-film providing apparatus for a vehicle according to claim 5, wherein each of the bonnet sprayers comprises a slot-shaped outlet, the slot-shaped outlet for emitting the high-pressures air generated by the compressor with a spraying angle and a spraying velocity, and a spraying quantity of air flow, wherein the spraying angle is set so that the jet stream sprayed on the windshield window of the vehicle can not change the air flow of the vehicle, and wherein the spraying velocity is set so that the velocity of the jet stream can be higher than that of the vehicle, and wherein the spraying quantity is set to correspond to the spraying angle and velocity.

11. A windshield-window air-film providing apparatus for a vehicle, the apparatus forming an air-film made of high-velocity air flow on a windshield window of a vehicle, the apparatus comprising: a compressor for generating high-pressure air; a wiper sprayers for receiving the high-pressure air and spraying jet streams; and a blowing pipe for feeding the compressed high-pressure air of the compressor to the wiper sprayers, wherein the apparatus further comprises a second control unit for selectively feeding the high-pressure air generated by the compressor to both sides of the wiper in accordance with rotational directions of the wiper, and wherein each of the wiper sprayers comprises: a wiper arm enclosing some portion of the blowing pipe for feeding the compressed high-pressure air; a wiper main body being connected to the wiper arm; and a sprayer enclosure being attached to the wiper main body, the sprayer enclosure for selectively spraying the high-pressure air fed by the blowing pipe in accordance with the rotational directions of the wiper main body under the control of the second control unit.

12. The windshield-window air-film providing apparatus for a vehicle according to claim 11 , wherein the sprayer enclosure comprises: two parallel conduits connected to the blowing pipe, the two parallel conduits feeding the high-pressure air to left and right sides of the wiper main body, respectively; and a plurality of air-emitting nozzles protruded from each of parallel conduits, the plurality of the air-emitting nozzles spraying the jet streams by using the high-pressure air.

13. The windshield-window air-film providing apparatus for a vehicle according to claim 12, wherein the air-emitting nozzles have different diameters according to the difference between the quantities of the supplied high-pressure air flow, and the shape of the cross section of the air-emitting nozzle is elliptic.

14. The windshield-window air-film providing apparatus for a vehicle according to claim 11 , wherein the blowing pipe comprises two passages for feeding the high-pressure air to the two parallel conduits.

15. The windshield-window air-film providing apparatus for a vehicle according to claim 11 , wherein the apparatus further comprises a sensor for sensing rotational directions of the wiper main body.

16. The windshield- window air-film providing apparatus for a vehicle according to claim 11, wherein the second control unit is constructed with a solenoid valve.