JPS5992300A - Preventive device for freezing of wing of aircraft - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an aircraft wing deicing and dewatering system, and more particularly to the use of a lightweight, monolithic, hard, non-metallic synthetic material and a novel wing deicing and dewatering system. Relates to components of de-icing systems.

Defreezing the leading edge of an airplane wing by spilling glycol and other antifreeze chemicals onto the surface of the leading edge of the wing to remove ice buildup or prevent icing on the mirror surface. It is well known. This type of deicing system generally utilizes a device to store the glycol, an auxiliary system to release the glycol to the front of the aircraft wing, and a device to control the flow and distribution of glycol to the front.

One challenge with some of the preferred methods of deicing systems of the type previously described is that they may not be appropriate for new aircraft designs. Another problem with some of the preferred methods is that when mounted on a surface, their weight may be excessive, thus making them impractical for use in small aircraft. This challenge is generally due to the use of heavy metal components in deicing systems. Another challenge with some of the preferred methods of de-icing systems of the type described is that it is necessary to distribute the glycol evenly across the leading edge in order to prevent all icing on the leading edge. The distribution support system is powerless. Consequently, it is necessary to use excessive amounts of deicing fluid to ensure that adequate deicing occurs. For example, the majority of priority de-icing systems use uncured fabric to form the leading edge of the airfoil and control the flow of glycol to the leading edge.

For example, U.S. Pat.
．． See 075,659. This type of uncured fabric construction is not considered appropriate for newer aircraft, especially jet aircraft. U.S. Pat. No. 2,249,940 discloses that a woven composite formed partly of a metal or alloy of gold and partly of woven thread is applied to the wing surface. It is shown that.

The patentee states that the metal or alloy wire prevents stretching of the fabric and provides the necessary permeability of the yarn to the deicing fluid. However, we believe that it would be difficult to effectively control the flow of deicing fluid with this type of structure. Moreover, this type of fabric adds too much weight, making it undesirable, if not impossible, for use in small aircraft. A more novel and preferred method of ice-breaking systems, shown in U.S. Pat. υ may force an uneven distribution of deicing fluid. United States Patent No. 3,423,05
One system, shown in Figure 2, involves the use of a porous stainless steel sheath to form the leading edge of the bow. However, this stainless steel exterior is heavy and
Poor dimensional and lack of density control within the sheath may not provide as uniform distribution of fluid as desired.

Yet another challenge with some of these preferred deicing systems is the lack of adequate equipment to control the flow of glycol from the storage device to the leading edge of the wing.

Insect deposits on the leading edge of a normal laminar flow plate disrupt the laminar flow on the wing surface, thereby increasing the drag of the wing, but this type of wing causes an overflow of fluid that seeps from the porous surface. No preferred method has yet emerged that has announced the possibility of deicing.

Accordingly, it is a general object of the present invention to provide an improved de-icing system that eliminates or reduces the above-mentioned challenges.

A more specific objective is to provide a de-icing system that distributes de-icing fluid to the leading edge of the wing in an even manner, while at the same time minimizing the amount of de-icing fluid required to prevent icing. That's true.

Another object is to provide a system that effectively controls the flow of deicing or dewatering fluid from storage to the front of the wing.

Another object of the present invention is to provide an ice-breaking and de-icing system that uses lightweight components, particularly components suitable for newer small aircraft.

Yet another object is to overcome the above-mentioned challenges with a relatively low cost and relatively simple design for de-icing systems (which are intended to include de-icing systems under this condition). ).

Accomplishing these and other objectives is the use of antifreeze or deicing fluid storage devices, lightweight, rigid, monolithic, porous, non-metallic fibers formed in the shape of the wing front. An improved ice melting system is implemented comprising a synthetic material and a device for controlling the flow of antifreeze or ice melting fluid from a storage device to an exterior surface of the synthetic material. Forming the front from a non-metallic synthetic material provides structural and thermal compatibility with wings made from similar composites. Due to the laminar flow maintained over the wing surface, the wing profile should not change substantially with the wing loading. Fiber composite materials offer a solid prospect for constructing highly rigid wings that never change shape under aerodynamic loads.

In a preferred embodiment of the invention, the device controlling the flow rate of the deicing fluid includes a microporous plastic membrane located between the storage device and the synthetic material. Preferably, the synthetic material is a six-way fabric consisting of woven fiberglass that is partially gilded with resin.

Rather, a distribution device in the form of a layer of Aramai r-fiber fabric is laminated to the composite outer surface to create a more even distribution of antifreeze fluid to the wing outer surface.

A de-icing system according to the present invention includes a tank located anywhere convenient on the airplane for storing an antifreeze fluid, such as glycol.

A pump is used to force this fluid from the tank to the porous front element. A fluid compatible unit is used to create a more even distribution throughout the porous leading edge element.

As far as described, this system is well known to those skilled in the art. In accordance with the present invention, an improved lightweight, rigid, monolithic, porous, non-metallic synthetic material is used to form the leading edge element and provide a porous surface capable of supplying antifreeze fluid.

As shown in FIG. 1, position 12 is designated to indicate that the leading edge element of the deicing system of the present invention may be used in a small aircraft. Fundamentally, the front elements of the ice-breaking system, which are designed to be installed along the leading edge 20 of the airplane's main wing 14, are located along the leading edge of the airplane's tail, i.e., the leading edge 22 of each horizontal stabilizer 16 and the vertical stabilizer. Other wing leading edges, such as leading edge 24 of plate 18, may also be used. To simplify the description of the deicing system of the present invention, only the leading edge elements forming the leading edge 20 of the main wing 14 of the airplane will be described. Although the structure and operation of each leading edge element of this system may change in size and shape when installed as the leading edge of another wing surface, fundamentally the main wing It is the same type of element as the 14 is equipped with.

As shown in FIG. It consists of a monolithic, porous, non-metallic composite material that is lightweight in nature and a device that controls the flow of antifreeze fluid through the element and onto the exterior surface of the element. In the preferred embodiment, leading edge element 26 is comprised of an outer shell 36 and an inner shell 38, which are rigid so as to define a cavity 32 therebetween. Outer shell 36 and inner shell 38 provide the integral stiffness needed to delimit the leading edge airfoil. Cavity 32 [■], under positive pressure with respect to the outer surface of shell 36, [■] carries fluid that is being forced into the cavity from the system's storage tank (not shown) through the collection inlet Nirasol 44. suitable for holding. The preferred leading edge element 26 similarly comprises a microporous plastic membrane 28 laminated within the cavity 32 between the outer and inner shells to control the flow of fluid through the guide element.

The preferred outer shell and inner shell each preferably consist of one or more layers, with each layer being woven as a six-way weave. Six-way textiles are famous. In addition to six-way fabrics, other multi-directional fabrics, such as U.S. Pat.
, 949, 126 or 1
A unidirectional weave could be used. As shown in FIGS. 4 and 5, a six-way weave 48 of this type is comprised of four separate groups of yarns. Weaving thread 5
The groups 0 and 52 extend in the Y direction and form two parallel layers as shown in the λ diagram. Thread 54 is X
The fourth group of yarns 56 extend in the direction υ and are inserted between the respective layers of yarns 50 and 52 to form a sixth layer. (5th
(See figure) Then, all the yarns of the fourth Daruso are twisted in two directions together with the yarns 50 and 52, respectively, so that they are tied together. The weave structure, thread thickness, and thread distribution of fabric 48 can be varied to create a fabric with the desired mesh and porosity distribution.

A preferred material for threads 50, 52, 54, and 56 is fiberglass. The fabric of the outer shell 36 is coated with a resin material to form a highly rigid synthetic material 40, but the synthetic material 4o does not fill all the holes in the fabric.
has a small hole. The outer shell 36 includes at least one additional layer 30A of fabric disposed on the outer surface of the shell to form an outer skin to increase abrasion resistance, toughness, and aerodynamic smoothness to the wing surface, The fibers are woven finely enough to more evenly distribute the antifreeze fluid in the fibers (under the trade name KFiVLAR), manufactured by E.I., Wilmington, P.
(such as some types of aramite fibers manufactured by the DuPont, De Nemours, and Nemours companies). Similarly, the inner surface of shell 36 can be equipped with a layer 30B of a material similar to layer 30A to provide an even higher degree of stiffness. The inner shell 38 is sufficiently impregnated with resin to be completely non-porous to prevent any flow of fluid.

Microporous membrane 28 is manufactured by Milliboer Company of Ford City, Vera, Massachusetts under the trade name HVLPOOOOlo to control the flow rate of antifreeze fluid through shell 36.
consisting of at least one thin film or plate of substantially uniform microporous polyvinylidene fluoride of the type manufactured, but containing another microporous film of the same or different material. Usability will be appreciated. Membrane 28 is affixed to the inner surface of shell 36 by gluing the outer edge of membrane 28 to shell 36 with a suitable adhesive.

Referring to FIG. 6, each leading edge element 26 is formed into a compartment 42 with each compartment adjacent to a plurality of cavities separated by bounding recesses 46 to form a divided cavity 32. ing. each cavity 32
An intake tube 44 is glued to the inner shell 38 and is adapted to connect to a fluid conduit (not shown) to communicate fluid between such conduit and the cavity 32. Let me contact you.

What follows is an example of how the front element 26 may be fabricated, and it is understood that the example is for illustrative purposes and is not restrictive.

The outer shell 36 is a vacuum bag made in a female mold.

Layer of dry fine weave aramite fiber fabric (+12
0 E.I. of Wilmington, Praue State by the trade name KKVLAR49.

(purchased from DuPont, De Nemours Company) is first placed in a mold to form the skin layer 30A. A six-way weave υ 40 mil (1i,v) thick glass tape prepreg is then placed over layer 30A in the mold. This 6-way glass prepreg is pre-applied with Dg tape.
Made from R331 epoxy resin, manufactured on a large scale by Shell Chemical Company of Hyuston, Texas (using NMA and BDMA processing agents);
Dilute with 50% MEK to cure the resin at approximately 250°F (
121° C.) for about 16 minutes.

Finally, another layer of aramite fiber fabric is placed over the six-way woven shiglas tape prepreg to form the inner layer 30B of the outer shell 36 as well as layer 30A. The resulting composition in the mold is a low-resin sandwich of aramite fiber fabric/fiber glass/aramite fiber fabric. Inner shell 38 has a thickness of 0.05 mm to conform to outer shell 36 during its molding process.
Vacuum bags are molded in the same female mold using a modification in which a 9 inch (1,5+nm) layer of cork is placed in the mold. Rectangular cork pillows of the same interest are compacted at regular intervals to match the cork layers to the regularly spaced cavities 32. The inner shell laminated material is model 7500-38 finish +, manufactured on a large scale by the Known Reinforcements Company of Exeter, New Hampshire.
1-62A Boat Fabric Prepreg is constructed from 6 layers of fiberglass with a 100% epoxy solid resin impregnation. Specifically, each 311 fiber glass is manufactured by soaking 40 mil (1 mm) thick six-way woven glass tape prepreg in 100% DER 331 epoxy resin from a former AA and BDMA agent processing company. The resin cures then at 250°F (12
Accelerate for 16 minutes in a 1 °C) o oven.

After the inner member was molded and dried, small holes were placed at the corners of each cavity 32 to provide inlets for deicing fluid. A polyethylene nipple 44 is adhered to each hole with a constructional adhesive such as EA 934 manufactured on a large scale by the Dexter Hysole Company of Pittsburgh, California.

The inner laminated shell 38 and the outer laminated shell 36 are then bonded with an intermediary sandwiched between two layers of polyvinylidene fluoride membrane. The outer edges and the boundaries between the cavities are glued with EA934 adhesive and tightened until the adhesive is cured. After curing, the edges are sandblasted and any leaks can be sealed with a suitable sealant such as Hysole F, 9 = 2039 room temperature curing epoxy resin.

A description of the operation of the ice-breaking system of the present invention follows.

An antifreeze fluid, such as glycol, is flowed from the central storage container into each cavity 32 under positive pressure, e.g. by a pump, through conduits (not shown). ) are carried to each nipple 44. Since the inner shell 38 has no pores, the pressurized glycol is passed through the microporous plastic membrane 28 and through the outer shell 36 of the shoe element 26 at a rate determined by the pressure of the fluid and the properties of the membrane 2B. flows. After the glycol passes through the outer shell small-porous synthetic material 40, it encounters a fine mesh outer shell 30A that distributes the glycol very evenly on the outer surface of the element 26. The pressure of the glycol is controlled to flow the glycol through the skin 30A at a sufficient rate to ensure that no ice forms on the leading edge 20 of the main R14. The glycol flow rate is kept as low as possible to minimize the amount of glycol needed to achieve the anti-ice objectives mentioned above.

Although a preferred embodiment of the invention has been described, the leading edge 26 may be modified without departing from the purpose of the invention. One possible variation of the invention is to remove the microporous plastic membrane 28 from the leading edge element 26 and control the fluid flow rate with the synthetic material 40 of the outer shell 36 of the element 26. The resin content of the interest rate 40, the composition of the resin and the composition of the fabric are the outer shell 3.
The porosity and porosity of shell 36 can be varied by controlling the flow rate of glycol through shell 36.

Another way to enable control of the flow rate of fluid through the synthetic material 40 of the outer shell 36 is to use a temporary filler in the resin matrix; in material 48, both of which are described in more detail below: [I] The composition of the resin of material 40 is a soluble or volatile filler that is leached or evaporated from the resin after molding of synthetic material 40 It can be modified to include agents. The particle size distribution of this type of temporary filler can be varied to result in a porous and microporous synthetic material 40 that controls fluid flow rates as desired.

[Unstable fibers such as IILdevinyl alcohol can be incorporated into the weave configuration of the fabric of Phase 48 in a predetermined manner.

When the fibers are leached from the material 48, the synthetic material 40 will maintain the desired porous and microporous texture to properly control the flow of fluid through the outer shell 36 of the element 26.

Besides its use in a deicing system for the leading edge of a wing in particular, the invention has other uses as mentioned above, one of which is to maintain the leading edge of a wing in a smooth condition. It is a provision for increasing laminar flow on aerodynamic surfaces, especially under conditions of cross-section. A steady, even flow of fluid (without the need for glycol) on the outer surface of the leading edge of the wing prevents particulate matter, especially insects, from sticking to the leading edge, thereby increasing the laminar flow over the wing surface. would minimize turbulence.

The invention described above has many advantages. Firstly, it allows the leading edge of the wing to act as a compartment for the ice-breaking system, and on the other hand, it reduces the weight added to the airplane compared to similar ice-breaking systems that use fabric metal. Minimized. The leading edge element 26 of the deicing system of the present invention is 50
It enables a huge amount of weight reduction. The use of lightweight, hard, non-metallic synthetic materials 48 allows for the construction of ice-breaking systems at even lower costs than currently available.

Additionally, the use of a hard, non-metallic synthetic material provides sufficient structural strength to the front element 26 while providing a porous structure that promotes even distribution of fluid. Additionally, skin 30 provides an aerodynamically smooth surface of element 26 to maximize laminar flow and minimize turbulence over main R14. In a preferred embodiment of the present invention, skin 30 is comprised of a fine weave aramite fiber fabric that also provides increased abrasion resistance to element 26.

The fine mesh of the aramite fiber fabric also makes the antifreeze fluid on the outer surface of the element 26 very smooth, thereby minimizing the chance of ice forming anywhere on the surface of the element 26. do.

Further variations and advantages of the invention will be apparent to those skilled in the art.

[BRIEF DESCRIPTION OF THE DRAWINGS] Figure 1 is a plan view of a typical small aircraft showing where the porous leading edge of the ice melting system of the present invention is used; FIG. 6 is a cross-sectional view of the porous leading edge element partially taken along line 2-2, FIG. 6 is an isometric back view of the inside of the porous leading edge element, and FIG. FIG. 5 is a fragmentary plan view of a single layer of a preferred six-way composite as used in FIG. In the figure: 26: Leading edge element 28: Microporous membrane 30A: Outer skin 30B: Rigid reinforcement layer 36: Outer shell 38: Inner shell 40: Rigid non-metallic synthetic material 44: Antifreeze fluid intake nipple 50.52 .54.56: Weaving thread 46: Hollow agent Hajime Asari

Claims (9)

[Claims] (1) For use as a device having an outer surface forming the leading edge of an airplane wing and pressurizing the fluid so that a predetermined flow rate of the fluid overflows the outer surface. A component having a conforming exterior surface, wherein the component is comprised of a rigid, monolithic, porous, non-metallic synthetic woven material, and wherein the pressurized fluid spills through the material to the exterior surface. A component characterized by controlling flow rate. (2) The component according to claim 1, wherein the material has at least a six-way structure. 3. A component according to claim 1, wherein the device for controlling the fluid comprises a microporous membrane. (4) said rigid, monolithic, porous, non-metallic composite material forming an outer shell defining said outer surface, said component further connecting said shell to retain said pressurized fluid; A component according to claim 1, characterized in that it consists of a non-porous inner shell cooperating with said outer shell to form a cavity therebetween. (5) The component according to claim 4, wherein the flow rate control device comprises a microporous membrane within the cavity disposed between the outer shell and the inner shell. (6) The component according to claim 5, wherein the microporous membrane is fixed to an outer shell. (7) The component according to claim 6, wherein the film contains polyvinylidene fluoride. (8) The component according to claim 1, wherein the synthetic material is a resin-impregnated fiberglass material. 9. The component of claim 8, wherein the synthetic material further includes a woven layer of aramite fibers disposed on the top surface to form the outer surface. 01. A component according to claim 9, characterized in that the textile layer is finely woven to create a wear-resistant surface and uniform fluid flow on the outer surface. 0]) Part according to claim 10, characterized in that said textile layer includes a second textile layer of aramite fibers arranged on said composite opposite said outer surface. . Q4. A component according to claim 11, characterized in that the composite includes a woven layer with at least a six-way structure. Typical leading edge hollow element made of rigid, monolithic, non-metallic porous and microporous synthetic material, 1+16
said element being taut to a porous backing and having a hollow space in front of said backing for receiving fluid under positive pressure conditions; controlling the flow of fluid through said element from said hollow space; An airfoil leading edge surface wetting system comprising: a device for transporting the fluid into the space; and a device for pressurizing the fluid. 0→ A resin-impregnated six-way fabric of fiberglass in which the porous and small-porous synthetic materials described above are knitted, characterized in that the synthetic material has a predetermined mesh and porosity. A system according to claim 16. 09. The system of claim 14, wherein the porosity of the synthetic material is determined by the amount of resin in the material. 15. The system of claim 14, wherein the porosity of the synthetic material is a function of a temporary material being transferred from the resin to the fabric. 07) System according to claim 14, characterized in that the porosity of the synthetic material is a function of unstable fibers being transferred from the fabric. 15. The system of claim 14, wherein the porosity is a function of the non-freezing viscosity of the fluid.