JPS6218400B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention This invention relates to a rear baffle structure for rotor blades, particularly aerodynamic rotor blade assemblies such as helicopter rotor blades. [Explanation of Terms] The main terms used in the present invention will be explained. a "Composite girder members" Currently, the girder members of helicopter rotor blade assemblies (spanwise longitudinal load-bearing structural members that primarily bear aerodynamic loads) are usually made from composite materials in order to be lightweight and strong. . The word "composite" is also used to mean "simply joining two or more members together," but in the present invention, it refers to "a spar made of composite material." b “Aft fairing structure” This term is not often used by those skilled in the art in Japan, but its original meaning is “Aft fairing structure”.
"Fairing" is commonly used as "straightening material" or "shaping material", so it means "the part that straightens the airflow behind the girder member", and in the present invention, "the core part, the composite girder rear end member and Used in the expression "rear rectification structure consisting of upper and lower outer panels." c. "Core" means "lightweight core, preferably made of foam or honeycomb", so-called "honeycomb core". d "Lay-up" To clarify the process between "lay-up" in this term and the so-called "adhesion", "lay-up" is defined as "processing by placing a reinforcing material such as resin-impregnated glass fiber into a mold". method”. e Subassemblies The aerodynamic rotor blade assembly is finally assembled by combining the individually manufactured subassemblies. This term is used because this "subassembly" is a unit of quality that can be manufactured in-house or procured from another company. The aforementioned "rear rectification structure" is also one of the sub-assemblies. f The following two main assembly jigs are used in the present invention.
It is one. "Adhesive assembly jig": A jig for assembling the rear rectifier structure. "Single assembly mold": A jig for performing final assembly using each subassembly. BACKGROUND OF THE INVENTION Since the advent of composite rotor blades, there has been a continuing desire in the industry to reduce manufacturing costs by slowing down or modifying the manufacturing process. However, composite rotor blades are still manufactured by combining a number of individually manufactured subassemblies. Most of them are sub-assemblies that have undergone multiple curing processes,
Each major subassembly requires a separate adhesive assembly jig. Conventional manufacturing methods for such composite rotor blades include, for example, the following subassemblies and final assemblies: 1 Subassembly of cap material, deicing blanket, and front end block. 2-digit subassembly. 3. Subassembly of spar, cap material, de-icing blanket, and front end block. 4 Trailing edge wedge subassembly. 5 Core sub-assembly of rear rectifier structure (without machining) with one skin. 6 Core subassembly of (machined) rear rectifier structure with both skins. 7 Final assembly including subassemblies 3 to 6 above. As readily understood above, this final assembly requires at least seven curing or bonding steps. Blade manufacturing that involves many curing and bonding steps is inevitably expensive, and this alone is undesirable. Therefore, it would be desirable to reduce the overall number of curing and bonding steps currently required to manufacture such composite rotor blades, resulting in lower manufacturing costs, while not adversely affecting the structural integrity of the blade. Of the various subassemblies mentioned above, it is the girder subassembly that poses the greatest barrier to manufacturing economy and optimum structural integrity. For example, one conventionally known method using a curing process is to back up the external surface of the spar to counteract the internal bag pressure acting inside the spar during the curing process to avoid structural damage. I had to apply pressure. The only suitable method so far is
The girder was made separately within one mold. As an example of this, Japanese Unexamined Patent Publication No. 16298/1983 discloses that three girder constituent parts 112, 113, and 114 are joined together by overlapping joints, as shown in FIG. 9 attached to this specification. A D-shaped hollow composite spar member 12' is formed, a trailing edge 103 is coupled to the rear surface thereof, and skin plates 28' and 30' are pressurized to the same, and near the leading edge, the spar member 12' A front end block 18' is inserted between component parts 113 and 114, and a deicing bracket 122 and a cap member 16' are mounted on the front edge surface of the component part 114 and connected under pressure. ·blade·
An assembly is disclosed. This includes three components 112, 113, 11 of the girder member 12'.
Reference numeral 4 denotes a mold which is used to separately form a mold that is joined to the final D-shaped shape.Then, the trailing edge 103 is joined to the rear surface of this girder member 12', and then the outer panels 28', 30' are formed. The final rotor blade assembly could not be completed without a pressure bonding method. In another conventional manufacturing method that uses a curing process, the girder trailing material is made separately from the girder, and the girder trailing material is assembled to the girder during the girder curing process. . However, this method is not satisfactory, one of the reasons being that it causes undesirable surface wrinkles on the spars, which impairs the surface adhesion with other parts of the blade and thus impedes load transfer. Ta. [Problem to be Solved by the Invention] Although the girder is a major element of the rotor blade, it has hitherto had to be manufactured separately for at least the reasons mentioned above, and it cannot be completed. It is clear that streamlining of fabrication could be achieved if a method were perfected that would eliminate the need to fabricate the girder as a separate subassembly. This method of making composite rotor blades does not require separate assembly of the completed spar, and the conditions that would impair the proper functioning of the spar do not arise at any time. has been desired. Accordingly, one of the objects of the present invention is to provide a rotor with a composite structure, preferably an aerodynamic rotor blade assembly, that can be assembled in fewer steps than conventional rotor blade assemblies and yet has superior structural integrity. - To provide a durable rear baffle structure as a subassembly of an aerodynamic rotor blade assembly that can be completed into a blade. Another object of the present invention is that a U-shaped girder rear end member is manufactured separately and then incorporated as a component of the rear rectification structure, and then a separately manufactured D-shaped composite girder member (hereinafter referred to as girder) is assembled. The purpose of the present invention is to provide a durable rear rectifier structure that can be fitted to the rear. A further object of the invention is to provide an aerodynamic rotor blade rear baffle structure of the above-mentioned purpose, the skin of which can be secured in a fail-safe manner. . [Means for solving the problem] The technical means used to solve this problem consists of a composite girder member with a longitudinal load-bearing structure in the form of a hollow cylinder with an approximately D-shaped cross section, and a longitudinal front end block. , a rear straightening structure for an aerodynamic rotor blade assembly comprising an elongated cap member and a long rear straightening structure, the rear straightening structure having: (B) having a length in the span direction to be fixed to the front end side of the core part and to the rear end of the girder member, and having a cross-sectional shape of a forward-facing opening; This is a composite girder rear end member having an approximately U-shaped load-bearing structure with a composite spar trailing end member having a shape complementary to the external surface shape and configured to be assembled with the composite spar member to form a spar of a rotor blade assembly of a monolithic complete composite load-bearing structure; and (C) upper and lower composite skin panels fixed to the outer surfaces of each of the upper and lower sides of the core portion and the U-shaped upper and lower pieces of the girder rear end material, both of which It consists of upper and lower composite skins whose rear ends are strongly connected to each other, and (D) the girder rear end material and both composite skins are capable of being subjected to heat and pressure. It is therefore made of a fibrous material pre-impregnated with a synthetic resin, which is combined with the girder member and the cap material to form a load-bearing structure. That's true. [Operation and Effect] The present invention has the following main features. The rear rectifying structure constituting the aerodynamic rotor blade assembly is constructed by firmly connecting the rear end of the spar, which is fixed to the outer surface of the core part, and the upper and lower outer panels. Since it is constructed as a strong cylindrical body with a completely closed cross-sectional shape, the entire rear rectifying structure is extremely strong even when subjected to external torsional force. In addition, since the outer surface of the core portion located therein and the inner surface of the three components are fixed to each other, the entire rear rectifying structure as one unit is very strong even if subjected to external torsional force, which is a good effect. have an effect. In order to connect and fix the rear rectification structure as an assembly unit to the rear end of the composite girder member constituting other units, U-shaped U-shaped parts of the rear end of the girder are attached to both upper and lower surfaces and the rear surface of the rear end of the girder member. Since the inner surfaces are fitted and fixed, it is possible to securely fix the rear rectification structure to the girder member while simplifying the structure and assembly connection. To connect it to the rear end of the girder, use the U-shaped cross section of the rear end of the girder, and attach the inner surface of the front end of the upper outer panel and the front end of the lower outer panel to the outer surfaces of the upper and lower sides, respectively. Since the inner surfaces are surface-fixed, it is possible to connect the upper outer panel and the upper part of the girder rear end material, and the lower surface outer panel and the lower part of the girder rear end material, with a very simple structure, and to make it extremely strong and easy to connect. It has good working effect. This has the advantageous effect of making the cylindrical shell structure, which constitutes a completely closed curve in cross-section by the rear end of the girder, the upper outer plate, and the lower outer plate, extremely durable. As mentioned above, this rear rectifying structure is extremely durable against torsional external forces.
Even if this spar trailing end member is torsionally subjected to external force when assembled and used in an aerodynamic rotor blade assembly, the stress generated at the joint with the composite spar member will not be concentrated in a small area, and the said joint will Since it can be easily dispersed over a wide range, the connecting part between the rear rectifying structure and the girder member has a relatively simple connecting structure, and has a good effect that it is easy to make the connection substantially strong. In the example shown in Figure 2, stress in the horizontal direction on the paper along the upper and lower outer panels is easily transmitted to the upper and lower outer surfaces of the girder members via the outer surfaces of the upper and lower sides of the rear rectifying structure, so that the stress is applied to the rotor blade assembly. In use after assembly, stress is well transmitted in the direction along the plane of the paper through the unit joints, so the entire rotor blade assembly is not subject to external torsional forces parallel to the plane of the paper during use. It is also very durable and has good working effect. When the cross-sectional shape shown in Figure 2 is subjected to a bending moment in a plane parallel to the plane of the paper in the state in which it is used after being assembled into the rotor blade assembly, the lower outer plate is subjected to a tensile force parallel to the plane of the paper. When the force is applied, the tensile force is transmitted from the inner surface of the front end of the lower skin plate to the outer surface of the lower side of the back end of the girder that is surface-joined, and from the inner surface of this lower side to the outer surface of the girder member that is surface-joined. It has a good effect in that force can be easily transmitted from the rear rectifying structure of the assembly unit through the joints with the girder members of other assembly units. This point also applies to the upper outer plate. At the joint between the rear rectifying structure as an assembly unit and the girder member, the upper surface of the front end of the lower skin plate and the rear lower surface of the girder member are connected via the inner and outer surfaces of the lower side of the girder member, and the front end of the upper skin plate Since the lower surface and the rear upper surface of the girder member are connected via the inner and outer surfaces of the upper side of the girder member, it is easy to strengthen the connection near the top surface and near the bottom surface of the connection between the two of the rotor blade assembly. ,
Even if the rotor blade assembly is subjected to an external force that bends the span direction of the rotor blade assembly up and down, it has a good effect of providing a rear rectification structure that can easily create a rotor blade assembly that is resistant to bending. For the above reasons, the present invention allows the aerodynamic load applied to the rear baffle structure to be sufficiently transmitted to the completed girder when assembled into a blade assembly. Also, by forming the spar tail end as part of the aft straightening structure, it is possible to separate, for example, three separate subassemblies, namely the cap stock, de-icing blanket, and front end block subassemblies, and the spar end block subassemblies. The need to manufacture three subassemblies is eliminated from the manufacturing process: the spars and caps, the deicing blankets, and the front end block subassemblies. Furthermore, the rear rectification structure including the girder rear end material can withstand the bag pressure that acts inside the girder rear end material during assembly due to the rigidity of the girder rear end member, and is able to withstand the bag pressure that acts inside the girder rear end material during assembly. There is no need to apply pressure. This feature of the invention is such that a single assembly mold is used within which the cap material, deicing blanket, front end block, and spar are included as assembly elements along with the rear baffle structure. These are the factors that have led to the ability to form composite blades with the rear baffle structure as various sub-assemblies. Furthermore, most of the components can be fabricated from cure-responsive materials during the formation of the rear baffle structure and final assembly, and this is in fact preferred. Next, embodiments of the present invention will be described in detail based on the drawings. Reference is first made to Figures 1 and 2, which show details of a composite blade 10 according to the invention. The composite blade 10 has, as its main part,
D-shaped spar 12, rear straightening structure 14 , cap material 16, front end block 18, and wing tip cover 2
0, including. The girder 12 is formed as a generally D-shaped cross-sectional structure with rounded corners that transitions in the span direction to a generally square base 22. This spar 12 is hollow and cylindrical and serves as the main load-bearing member of the blade, to which all other components are assembled and supported to create the composite structure of the blade. As such a supporting spar, its outer surface is shaped to accommodate the other components of the blade and to give the blade an airfoil cross-section. A significant feature of this invention is that the rear spar is made as a separate member 24, which is capable of carrying not only the operational flight loads of the helicopter, but also each curing step applied to this member, if any. It is able to withstand the temperature and pressure requirements of According to the invention, the spar rear end material 24 is first secured to the rear straightening structure 14 and then attached to the spar 12 as part of the rear straightening structure. The spar trailing end member 24 has a generally U-shaped cross-section, which transitions in the span direction to fit with the spar to form the root portion 22 of the blade. Rear rectification structure 14 excluding the rear end material 24 of the girder
includes a lightweight core 26, typically made of foam or honeycomb; a top skin 28;
It includes a lower skin 30 and, in most cases, also a trailing edge wedge 32 . The core portion 12 is a combination of the lightweight core 26 and the trailing edge wedge material 32.
Call it 6. (FIG. 5) Preferably, each of these components of the rear rectifier structure is continuous over the entire span.
However, each of these components could also be any suitable number of separate box structures 34, each including a core, a top skin, a bottom skin, and in most cases also a trailing edge wedge. In the assembled state, the box structures are separated by partition ribs 36 (only schematically shown in FIG. 1).
These partitioning ribs 36 are preferably made of rubber. The cap material 16 is preferably made of a metal such as titanium, but any non-metallic material may be used as long as it can prevent corrosion. Regardless of whether the main body of the cap material 16 is made of metal or non-metal, there is a non-metal part in the inner part,
Together with the spar 12 and the spar rear end piece 24, it forms the blade root. Aspects determined by the various components discussed above are important to clarify and will be discussed in order to better understand the manufacture of this rotor blade assembly. The outer surface of the cap 16 defines the leading edge 44 of the blade, while its inner surface defines a leading end block engagement section 46, a spar engagement section 48, and an aft baffle skin engagement section 50. It is clear from FIG. 2 how widely each of these parts engages. If the blade incorporates a de-icing blanket, the leading end block engagement portion 46 would rather engage the de-icing blanket 40, as shown in FIG. The front end block 18 has a spar engaging surface 51 that engages the spar 12.
has an outer surface provided with a spar rear end material engaging portion 52;
The core 26 of the rear rectifying structure 14 has front, rear, upper, and lower sides 54, 56, 58, and 60 formed therein. Further, the rear baffle structure 14 shapes the trailing edge 76 of the blade. As seen in FIG. 2, in the blade assembly, the outer surface of the spar 12 forms a spanwise continuous recess 53 (FIG. 5) with the cap 16 and along the cap 16 and forward end block 18. Slot 55 (fifth slot) continuous in the span direction
(Figure), respectively. Having described the various components of this composite blade and their interrelationships, the manufacture of the rotor blade will now be described with reference to FIGS. 3-7. Of the various jigs and tools used during fabrication, these figures only show those to the extent necessary for understanding the invention. In preparation for creating the aft baffle structure 14 , the lower surface 60 of the core 26 is cut or machined by conventional methods to closely match the slope of the mating surface 62 of the adhesive assembly jig (FIG. 3). When the outer panel is placed on the jig portion 62, the wall surface of the core cell is processed to be substantially parallel to the girder rear end member 24. Alternatively, a core 26 having a surface 60 that exactly matches the inclination of the jig portion 62 from the beginning may be used. The adhesive assembly jig also includes a pressure block 64 with a rubber pad 66 as shown in FIG. These other parts of the adhesive assembly jig are not shown but are well known to those skilled in the art. One of the features of this invention is that the lower skin 30 can be procured in the form of a hardened or unhardened plate. In any event, this skin is attached to face 60 of core 26 using a suitable conventional adhesive.
attached to. The adhesive is preferably applied to both opposing surfaces, and heat and pressure are applied to the adhered core and outer panel while they are still in this adhesive assembly jig, thereby fixing the opposing surfaces. One of the characteristics of this invention is that the outer panel 30 is first laid up in the jig 62 (here, "layup" refers to a method in which a reinforcing member such as resin-impregnated glass fiber is placed in a mold). After the core 26 is positioned as described above, the jig is assembled and the heat and pressure of the curing process is applied to the contents. As a result of the curing reaction, the laid-up skin is affixed to the core 26 and simultaneously fabricated into a structural member. The technique of laying up and then curing parts to form them is well known.
No need to explain in detail. The lower skin plate 30 is prepared by any of the methods described above.
After the core is secured to the lower surface 60, the upper surface 58 is machined to have the desired outer shape 58'.
That is, this outer surface 58' forms the upper surface of the core into the desired airfoil shape. Next, the top skin 28 is placed in another jig section 68 of the adhesive assembly jig, only a portion of which is shown in FIG.
Place. Then, as shown in FIG. 4, the spar rear end piece 24 is placed, and as mentioned above, the machined core 26 and the lower skin 30 attached thereto are also placed into this jig and machined. The machined surface 58' engages the top skin 28, and both skins and the core engage the spar trailing end 24, respectively. If a trailing edge wedge 32 is included, it may be assembled with a machined core with a bottom skin 30 or, as shown in FIG. The machined core with plate 30 may be positioned within the fixture so that the trailing edge wedge 32 engages the rear surface 56 of the core 26. This trailing edge wedge material 32 is inserted before the girder rear end material 24 is inserted. Once rear baffle structure 14 is thus assembled, the remaining portions of the jig are coupled to jig portion 68 in preparation for beginning the fastening process. One such portion is the side portion 70, which includes a mandrel 72 and an inflatable bladder 74 extending into the recess forming the spar back end 24. The mandrel will, of course, support the spar back end during the fixing process, and the bag 74 is for obtaining an even bond over the entire engagement surface. As already mentioned, one of the features of this invention is that the skin 28 can also be procured in a hardened or unhardened state, and the trailing edge wedge 32 can also be provided in a desired shape, hardened or unhardened. But that's fine. In this case, the top skin 28, spar tailings 24, machined core 26 with bottom skin 30, and trailing edge wedge 32 are bonded by applying a suitable conventional adhesive to each mating surface. Heat and pressure are applied to the component while it remains in the adhesive assembly jig to secure the respective mating surfaces. One of the characteristics of this invention is that the upper outer plate 28 and the trailing edge wedge member 32 are first connected to the jig portion 68.
The machined core 26 and the girder rear end material 24, which are laid up inside and the top skin 30 is fixed to, are positioned in the same way as in the previous case, the jig is assembled, and the contents are exposed to the heat of the curing process. There are things that can apply pressure. As a result of the curing reaction, the laid-up top skin 28 and laid-up trailing edge wedge 32 are made into a structural member at the same time that all mating surfaces are secured. However, in either case, the girder rear end material is manufactured separately. To make it, it is preferable to first lay it up in a mold and then mold it by applying heat and pressure during the curing process. Even if the rear baffle structure 14 consists of a separate box structure 34, the manufacturing method is basically the same as described above. The lower skin panels 30 are placed side by side within the jig and are fixed to each corresponding core lower surface and partition rib. At the same time, each engaging side surface between the core and the partitioning rib of each box structure is also fixed, and the other side surface of each partitioning rib is also fixed to the core side surface of the adjacent box structure. For the reasons already mentioned, before this fixing step is performed, the lower surface of each core or partition rib section is cut or machined to exactly match the inclination of the jig portion 62. Thereafter, the process of creating the rear baffle structure 14 proceeds as previously described. Both upper and lower skins of the core and partition ribs and trailing edge wedges are preferably laid up and hardened. As an alternative method to the above-mentioned method, in both of the above cases, the core or the partition rib is cut for the purpose of machining the upper surface so that the core and the partition rib have the required external shape, and then the core or the One method involves first assembling a mock plate on the underside of the core and partition ribs. Thereafter, the dummy plate is removed, and both the upper and lower skin plates, the trailing end of the spar, and the trailing edge wedge if necessary are fixed in accordance with the method described above. One of the characteristics of this invention is that both skin plates and the trailing edge wedge material are laid up and all the engaging surfaces are fixed by hardening, and at the same time,
There are things that can be made into structural members. The simulated board material may be a material of an appropriate thickness and easy to handle. As yet another alternative to the method described above, it is also preferable to procure a core 26 whose both surfaces 58 and 60 have been machined into the desired external shape. In this case, as a characteristic preferred embodiment of the present invention, the core 26, both outer plates 28, 30, the rear end member 24 of the girder, and the rear edge wedge member 32 are assembled and arranged as shown in FIG. , the rear baffle structure 14 is created by simultaneously securing the engagement surfaces using an adhesive and a predetermined amount of heat and pressure. One of the features of this invention is that both skin panels and the trailing edge wedge material are laid up during assembly together with the procured core and trailing edge material, and all engaging surfaces are fixed by curing. At the same time, there are things that can be made into structural members. After the rear baffle structure 14 is created, it is assembled into the rotor blade 10 as shown in FIGS.
A single assembly mold 78, 8 with other parts
It is assembled with 0.82. The preferred method is to lay up the leading end block 18 and spars 12 in the same manner as the trailing spar ends 24, the skins 28, 30, and the trailing edge wedge 32, and final cure in a single assembly mold. It is created into a structural member during the process. The front end block 18 is laid up directly on the cap 16, and the spar 12 is laid up on an inflatable and preferably rigid mandrel 92 and in this state placed within the cap 16. For final assembly, the front end block 18, spars 12 and deicing blankets 4 are assembled as previously described.
0 and cap material 16 are placed in the front portion 78 of a single assembly mold and positioned using leading edge jig knobs 84. If a metal or non-metallic cap material 16 is used, it is preferable to use a spreading tool 86 with latches 88 and 90. Spread the cap material sufficiently with the holes 88 and 90 so that the front end block 18 and the spar 12, or the front end block 18, the deicing blanket 40, and the spar 12 are inserted into the cap material, The rear baffle structure with the spar rear member 24 allows for successful engagement with the cap 16 and the spar 12 for assembly. Once the blade has been assembled and positioned snugly against the front section 78 of the single assembly mold, the front section 78 can be secured to its pins by suitable means (not shown). 94 through the position shown in FIG. 6 to the position shown in FIG . It rests within the rear portion 80 of the assembly mold.
A positioning support 96 is provided to partially support the assembled blade during rotation of the forward portion 78 and to properly position the rear portion 80.
and a support plate 97 are provided. This positioning support 96 includes one arm 98 and a two-part receiver 100 that can be fixed to each other by means not shown in the drawings for receiving the end portions of the joined outer panels 28 and 30. It consists of This arm 98
and the receiver 100 are mutually rotatable. The ends of both plates are intentionally shaped as shown in Figures 3-7, so that the blades can safely pivot with the front part 78 of the mold, and to avoid any of the problems already mentioned. during assembly of the rear baffle structure shown in FIG. 5 with the rear baffle structure shown in FIG. Of the means for assembling the rear rectifying structure into the assembly shown in FIG.
All values other than 0 are conventionally known and are not shown in the figure. The rear part 80 of the mold is provided with a recess 102 in which one half of the receiver 100 is received. This end is finally removed from the blade to form the blade trailing edge 76. For a blade assembled as shown in Figures 6 and 7, a preferred embodiment of the present invention includes only the rear rectifying structure as a subassembly; in this embodiment, the following surfaces are engaged: They are attached to each other, but they are not stuck together. That is, the spar engaging surface 51 of the front end block 18 engages with the spar 12, and the front end block engaging portion 46 of the cap member 16 engages with the front end block 18 or the deicing blanket 40 as the case requires.
The girder engaging portion 48 of the cap material 16 engages with the girder 12.
The rear rectifying outer plate engaging portion 5 of the cap material 16
0 is engaged with the rear straightening outer plates 28 and 30, and the spar rear end material engaging portion 52 of the spar 12 is engaged with the spar rear end material 24. The final assembly is completed by lowering the upper portion 82 of the single assembly mold into a closed position, as seen in FIG. 7, and applying heat and pressure to the assembly blade. For this purpose, the upper part 82 is connected to a press, which is not shown in the figures. Further, as seen in FIG. between the inner surface of the girder inside the area, i.e. the outermost layer of cap material, the next layer of skin, the inner layer of the girder end material,
and the innermost D-shaped girder layer are bonded together to form a spanwise continuous and extremely strong wall. This design is referred to as a "tuck-in" design, and the tuck-in walls can withstand shear forces along the longitudinal surfaces of the rotor blade airfoils, providing extremely effective load transfer while simultaneously It shall be capable of withstanding shear forces along this wall in the spanwise direction of the rotor blades to provide highly effective load transfer, and shall be sufficient to withstand the longitudinal bending and torsional strength of the rotor blade assembly. I can do it. Therefore,
It is highly effective to assemble and secure the rear baffle structure with the spars and cap material to provide a fail-safe design. This is also highly effective from the standpoint of transmitting load to the rear rectifying structure. This has the advantage that the overall load distribution is large and the load-bearing capacity of the rotor blade itself is large. As already mentioned, one feature of the present invention is that the spar trailing end member extends in the span direction to form the root of the blade together with the spar and cap material. The spars, caps, and sparse tails transition at the root of the blade to create a preferably square cross-section. Because the spar is preferably formed as a laid-up structure that is cured in a single prefabricated mold, it is important that the spar tail end extends beyond the rear straightening structure and to the same extent as the spar. Ensures that the spar is properly formed during the curing process. The following is an example of the operating parameters used in manufacturing a composite blade according to the present invention using the lay-up method. 1. Use pre-impregnated monofilament fibers as the lay-up material. 2 Rear rectifier structure is 50~100psi (3.5~7Kg/
cm ² ), cure at 250㎓ (120℃) for 2 hours. 3-digit rear end material is 70-100psi (5-7Kg/ ^cm2 ), 250
〓Cure at (120℃) for 2 hours. 4. The curing process in a single assembly mold is performed at 250 mm with a girder bag pressure of 70-100 psi (5-7 Kg/cm ² ).
(120℃) for 2 hours. When using a titanium cap material and deicing blanket, a pressure of 70 to 100 psi (5 to 7 kg/kg) is required to bond the deicing blanket to the cap material.
cm ² ), requires an adhesive method that requires 2 hours at 250°C (120°C). As is clear from the above description, each of the objects of the invention stated at the beginning has been achieved, and an ideal composite structure such as a composite rotor blade has been obtained. Furthermore, according to the present invention, the girder only needs to be heated to the curing temperature once, and during the curing process, bonding of the bonded surfaces occurs simultaneously, increasing the bondability of all bonded surfaces. As a result, a product with superior reliability and safety compared to conventional manufacturing methods has been provided. Moreover, the attachment of the spars to the rear baffle skin is a fail-safe construction and eliminates the need for close tolerances and difficult secondary bonding in critical boundary areas. Note that although numbers are written in the claims section for convenient comparison with the drawings, the present invention is not limited to the structure shown in the accompanying drawings.

[Brief explanation of the drawing]

FIG. 1 is a top view of a rotor blade assembly for a helicopter according to the present invention, and FIG. 2 is a top view of the rotor blade assembly taken along line 2--2 in FIG.
Cross-sectional views of the assembly, Figures 3 to 7 show each step of manufacturing the composite rotor blade assembly according to the present invention, Figure 8 is a detailed view of Figure 2, and Figure 9 is a diagram of the conventional example. FIG. 3 is a cross-sectional view of the rotor blade assembly. 10...Composite rotor blade assembly,
12... Girder member, 14 ... Rear rectification structure, 16...
...Cap material, 18...Front end block, 24...
Girder rear end material, 26...Core, 28...Top outer plate, 3
0...Lower outer plate, 126...Core part.

Claims (1)

[Scope of Claims] 1. A composite girder member 12 having a hollow cylindrical longitudinal load-bearing structure with a substantially D-shaped cross section, and a longitudinal front end block 18.
A rear straightening structure for an aerodynamic rotor blade assembly comprising: (A) a longitudinal cap member 16; and a longitudinal rear straightening structure 14 ; (B) a generally triangular core portion 126 having an upper side and a lower side; , a composite girder rear end member 24 having a load-bearing structure and having a substantially U-shaped cross-sectional shape with a forward opening, and the U-shaped inner surface of the girder rear end member 24 is similar to It has a shape complementary to the outer surface shape of the upper surface, lower surface, and rear surface of the letter-shaped rear portion, and is assembled together with the composite girder member 12 to constitute a girder of a rotor blade assembly having a complete composite load-bearing structure. (C) fixed to the outer surface of each of the upper and lower sides of the core portion 126 and the U-shaped upper and lower pieces of the girder rear end material 24; The upper and lower composite outer panels 28, 30 are made up of upper and lower composite outer panels 28, 30, and the rear ends of these composite outer panels 28, 30 are strongly connected to each other,
and (D) the girder rear end material 24 and both composite outer panels 28, 3
an aerodynamic rotor blade assembly made of a pre-impregnated synthetic resin fibrous material which is combined with the spar member 12 and the cap material 16 into a load-bearing structure by the application of heat and pressure; Rear rectification structure.