RU2054358C1 - Method of obtaining complex-shaped laminated articles by winding and the winding for its realization - Google Patents

Abstract

FIELD: manufacture of building materials. SUBSTANCE: technological bottoms with areas of circular cross-sections and with portions of smooth transitions from article mandrel to the perimeter of maximum cross-section of bottom are assembled to face ends of article mandrel. Then calculated mandrel model is moulded in the form of continuous combination of reduced surfaces of shape of bodies of revolution. The zone of disposition of working body trajectory is prescribed to working area of machine. The borders of wound portions are changed. The portions which do not satisfy the requirements of winding as well as portions of unstable winding are identified. Corrections at the pattern angles of winding and of number of starts are assigned. Sequences of control programmes for layer winding are worked out and the shells are moulded. EFFECT: enhanced quality of making articles of compound materials. 4 cl, 34 dwg

Description

 The invention relates to technology and tooling for the manufacture of composite products of complex shape by winding methods.

 Known in the manufacture of products from composite materials are methods of winding various shells of complex shape such as toroids, prismatic and box-shaped products of constant polygonal convex non-circular cross section due to the relative movements of the layers and the wound surface within the working area of the machine, usually with numerical control, while winding is carried out by laws of geodesic lines with a specified entry angle or with a slight deviation from geodesy unidirectionally, i.e. with rotation around the longitudinal axis in one direction.

Known methods for producing layered shells by winding methods include the formation of a calculation model and the spatial path of the working body relative to the surface of the mandrel, the formation of layers and curing [1]
Also known are mandrels for manufacturing wound products of complex shape, containing a portion of the main part of the product and technological bottoms [2]
When winding multilayer shells of complex shape not of rotation bodies, due to pressure non-uniformity along the section contour and local extrusion of the binder, thickenings of the wound package are formed, which mechanically remove and thereby reduce the strength of the product.

 Particularly problematic is the issue of winding shells of a non-circular cross section of products such as a spar of a rotor blade of a helicopter with a complex surface shape on which, if it is possible to describe the surface mathematically, the geodesic lines of the winding pattern, when implemented by known numerical methods, specify piecewise discontinuous functions, which requires for each meridional classical methods for describing the process to set a strictly unambiguous relationship with the starting point along the perimeter of the original cross section. For each unit layer ribbon for such surfaces, its own control program was required, even if the surface of the products meets the winding condition, and the winding pattern corresponds to the continuity condition on the surface under consideration. It was practically not possible to develop a control multi-coordinate program by known methods, despite certain attempts. Especially problematic is its debugging, adjustment, and operation. For example, the introduction of correction with the known method of developing a control program is a more complicated task than the development of the program itself.

With the considered methods, it is problematic to use winding devices containing several synchronous heads. Winding with small angles α <30 ^{o is} problematic, especially for shells of products without bottoms, as well as products obtained on non-rigid mandrels of complex shape. Not on all the desired winding patterns assigned by the designer of a product such as a helicopter propeller blade spar, the continuity of the wound layer is possible with known methods for producing it.

 Quite often, surfaces such as a spar of a helicopter rotor blade and other similar aerodynamic surfaces are obtained experimentally using plazas and other types of patterns, i.e. without mathematical description. In these cases, the questions of setting winding patterns by known methods are not defined.

 The aim of the invention is to obtain continuous and stable layers on various mandrels of products of complex shape of the surface of non-rotating bodies with a large ratio of length to the perimeter of the cross section described by sequences of unequal piecewise discontinuous functions, and on mandrels with experimentally obtained surfaces, and also to increase the productivity of the spiral process winding and the quality of such shells.

±

где C_Σ суммарный угол поворота за цикл по условию заходности;
n количество полных оборотов средней линии рисунка намотки за цикл;
m число, указывающее заходность рисунка намотки (1 одно, 2 двух, 3 трехзаходный и т.д.);
C_i=

угол поворота на смещение между двумя соседними лентами слоя;
l ширина ленты;
α угол намотки (т.е. угол между линией рисунка намотки и меридианом в рассматриваемой точке поверхности);
R максимальный радиус поверхности модели, при выбранной минимально заходности m определяют и вносят поправки в соответствии с C_Σ в первоначально заданный рисунок намотки, далее определяют узловые точки цилиндрического закона движения, задающего цикл виток слоя с отклонением от геодезии в пределах условия ±Φ < f, где Φ угол отклонения от геодезии; f угол трения наматываемого материала и поверхности, после чего многораскладочным раскладчиком формируют слой, затем для каждого последующего слоя измеряют габаритные размеры намотанной оболочки, вводят новые размеры в циклический закон движения формообразующего слоя, а направление поворота линии рисунка намотки при формировании последующего слоя меняют на противоположное.The goal is achieved in that in a method including the formation of a calculation model and a spatial trajectory of the working body relative to the surface of the mandrel, determining corrections, shaping the layers and curing, the calculation model of the mandrel in the form of a continuous set of reduced surfaces of the shape of bodies of revolution with perimeters in cross sections meeting the condition In _gm ≥ b _ro , where b _{gm is the} perimeter of the cross section perpendicular to the longitudinal axis at the points of the geometric model under consideration; b _ro perimeter section perpendicular to the longitudinal axis in similar locations real mandrel, wherein in the working area of the machine set zone trajectory executive authority limiting manner constructed with technological gap by the most radially distant points of cross-sections process the mandrel, and then determine the total rotation angle the executive body according to the initially specified winding pattern for the tape laying cycle and replace this angle with the nearest rotation angle, based on the conditions of continuity and and reliance in accordance with the dependence
C _Σ = 2πn ±

±

where C _{Σ is the} total angle of rotation per cycle according to the condition;
n the number of full revolutions of the middle line of the winding pattern per cycle;
m is a number indicating the occurrence of the winding pattern (1 single, 2 two, 3 three-way, etc.);
C _i =

the angle of rotation at the offset between two adjacent ribbons of the layer;
l tape width;
α winding angle (i.e., the angle between the winding line and the meridian at the surface point in question);
R the maximum radius of the surface of the model, at the selected minimum set m, is determined and corrected in accordance with C _Σ in the initially specified winding pattern, then the nodal points of the cylindrical law of motion, which defines the loop cycle of the layer with deviation from geodesy within the limits of the condition ± Φ <f, are determined where Φ is the angle of deviation from geodesy; f is the angle of friction of the material being wound and the surface, after which a layer is formed by a multi-folding laying device, then the dimensions of the wound shell are measured for each subsequent layer, new dimensions are introduced into the cyclic law of motion of the forming layer, and the direction of rotation of the winding pattern line when forming the next layer is reversed.

 The method also differs in that, with a fixed mandrel of low rigidity, it is supported by intermediate manipulators equipped with transverse supports, having actuators controlled by sensor signals switched by a longitudinally movable winding device.

 In addition, the method is characterized in that when forming multilayer shells that do not have high technical and technological requirements, the direction of rotation of the winding pattern line is changed through several layers.

 In a mandrel containing a section of the main part of the product and technological bottoms, between sections of the main part of the product and technological bottoms, sections of smoothly connected linear transitions from the main part of the mandrel to the circular perimeter of the maximum section of the bottom perpendicular to its axis with transition nodes γ proportional to the smallest winding angles α on these sections, and the technological bottoms in their maximum sections are equipped with sections of cylindrical or conical stabilization belts.

In FIG. 1-9 shows the mandrel in two projections; in FIG. 10-12 shows a machine with numerical control for implementing winding on a technological mandrel; in FIG. 13-16 shows in two projections a mandrel with bottoms; in FIG. 17 shows the calculated geometric model of the mandrel; in FIG. 18 shows the trajectory of movement of T _i .T _j heads; in FIG. 19-22 shows the winding layer with a sequence of tapes, respectively, ahead and backward; in FIG. 23 shows the winding of tapes in the trunnion area; in FIG. 24-34 shows in two projections the formation of a product on a mandrel in sections of various shapes.

 The method is carried out on a winding machine.

 The machine has a bed 1 of a modular design, on which there are supporting headstock 2, equipped with spacer pins 3 with cartridges 4 for securing the technological mandrel 5, carriage 6 with multi-folding winding device 7, drive 8 of carriage 6, drive 9 of spreaders, drive 10 of the winding device, intermediate manipulators 11 provided with transverse supports 12. On the bed 1 are also sensors 13 for switching manipulators 11 with the carriage 6 of the winding device 7. The winding device 7 of the machine is mounted in the housing 14 and closed lenok on the carriage 6. On the swivel chase 15 (see Fig. 3 and 4) of the winding device are disposers with self-aligning axes II folding heads 16, which in addition to rotation around the axis of the line (axis of the mandrel) from the drive 10 of the winding device have independent independent radial movements from the drive 9. In this case, the folding heads 16 with the possibility of self-installation around the axes II are mounted on the holders 17.

The holders 17 together with the heads 16, in turn, have the ability to adjust rotation around the axes II-II and are fixed by the latches 18 in the right or left position (see Fig. 3 and 4) relative to the rods 19 with guides for the rollers 20. The rod 19 is provided rails 21 with drive gears 22 on the axles 23. The folding heads 16 have folding rollers 24, which are mounted with transfer rollers 25 either on additional bushings 26 mounted around the axles III-III, mounted in the folding heads 16, or directly mounted in the askladochnyh heads 16. In pursuit 15 also set reel 27 for receiving the separating substrate 28 from the take-up reel 29 pictures, tensioner device 30, the rollers 31 lentotraktov. The last roller of group 31 (see FIG. 4) is tangent to axis II in the left position of the folding head 16 (for the left rotation of the swivel shoulder strap 15), and for the right rotation of the shoulder strap 15 (see FIG. 3) there is a roller 32 that is tangent to axis II in the right position of the folding head 16. Technological bottoms 34 and 35 are attached to the ends 33 of the mandrel 5 with zones a and b of circular sections A-A and II and with sections c and d of smooth transitions 36 and 37 from the mandrel 5 of the product to perimeters of maximum circular sections 38 and 39. In FIG. 6 shows a design geometric model 40 of mandrel 6. FIG. 7 shows the trajectory of the movement of T ₁ -T _{j of the} folding heads 16. Regardless of the cross-sectional profile of the wound mandrel, it is possible to form a layer by a sequence of tapes 41 “ahead of” or “behind” (Fig. 8, 9). In the trunnion zone, layers 42-44 of the multilayer shell are stacked according to different control programs with trajectories T ₁₁ , T ₁₂ , T ₁₃ and with a minimum clearance ρ.

 This method involves obtaining products of various sections, lengths, with tips, bottoms and without them.

 The method is as follows.

At the first stage, a technological mandrel 5 is developed and manufactured. For this purpose, technological bottoms 34 and 35 with zones a and b of circular sections AA and II in planes perpendicular to the axis of rotation are mounted on the ends 33 of the mandrel of the product (see FIG. 5). winding pattern (mandrel installation axis), and with sections c and d of smooth transitions 36 and 37 to perpendicular to the mandrel installation axis, the perimeters of maximum sections 38 and 39 of bottoms 34 and 35 with transition angles γ _i proportional to the smallest winding angles α in these sections. Then, at the next stage, a geometric calculation model 40 of the technological mandrel 5 is formed (see Fig. 6) in the form of a continuous combination of an organic minimum number H of sections 1, 11, N, given elementary surfaces of the form of bodies of revolution with diameters D ₁ , D ₂ , D ₃ , D _{H + 1 of the} connection of these elementary bodies of revolution with input angles α ₁ , α ₂ , α ₃ , α _{Н + 1 of the} winding pattern and with perimeters in the current cross sections corresponding to the condition
b _gm ≥ b _ro , (1) where b _{gm is the} perimeter of the cross section perpendicular to the longitudinal axis at the points of the geometric model under consideration;
b _ro perimeter section perpendicular to the longitudinal axis points in similar real mandrel.

(2) где К количество лент, необходимых для слоя;
α угол намотки (т.е. угол между линией рисунка намотки и меридианом в рассматриваемой точке);
l ширина ленты;
b_гм из условия (1).Condition (1) for the formation of the calculation model of such a technological mandrel is set to form the required number of tapes to obtain a layer
K

(2) where K is the number of tapes required for the layer;
α winding angle (i.e., the angle between the winding line and the meridian at the point in question);
l tape width;
b _um from condition (1).

(3) задают Δ b_ст относительную величину перекрытия лент в слое.Moreover, in accordance with the expression (3)
Δb _from =

(3) set Δ b _{article the} relative amount of overlap of the tapes in the layer.

In the working area of the machine, the area of the trajectory of the working body (folding heads) is defined, limited by the generatrix T ₁ , T ₂ , T ₃ , T _j constructed (see Fig. 7) by straight lines and with approach (for example, equidistant) over the bottoms along the most radially remote cross-sectional points of a real technological mandrel with a technological gap ρ _i . In this case, the generatrix of the trajectory itself in the marked working area is set either along the generatrix T ₁ , T ₂ , T ₃ , T _j , or by a line close to it.

±

(4) где C_Σ суммарный угол поворота за цикл по условию заходности;
n количество полных оборотов средней линии рисунка намотки за цикл;
m число, указывающее заходность рисунка намотки (1 одно, 2 двух, 3 трехзаходный и т.д.);
C_i=

угол поворота на смещение между двумя соседними лентами слоя;
l ширина ленты;
α угол намотки (т.е. угол между линией рисунка намотки и меридианом в рассматриваемой точке поверхности);
R максимальный радиус поверхности модели, и при минимально допустимом m определяют узловые точки циклической управляющей программы. Условия периметров (1), необходимого количества лент (2) и заходности (4) определяют комплексное геометрическое условие сплошности. При очевидности первых двух слагаемых в выражении заходности (4) третье слагаемое

в зависимости от знака определяет последовательность укладки лент: "с опережением", т.е. с увеличением угла поворота на

(см. фиг. 8), или "с отставанием", т.е. уменьшением угла поворота на

(см. фиг. 9) за цикл укладки ленты слоя.At the stage of development of the control program for the control winding, an estimated calculation C is performed of the total rotation angle of the folding heads according to the initially specified winding pattern for the installation cycle of a single tape and the angle C is replaced by the rotation angle C _Σ , based on the conditions for the winding pattern, expressed by the dependence (4)
C _Σ = 2πn ±

±

(4) where C _{Σ is the} total angle of rotation per cycle according to the set condition;
n the number of full revolutions of the middle line of the winding pattern per cycle;
m is a number indicating the occurrence of the winding pattern (1 single, 2 two, 3 three-way, etc.);
C _i =

the angle of rotation at the offset between two adjacent ribbons of the layer;
l tape width;
α winding angle (i.e., the angle between the winding line and the meridian at the surface point in question);
R is the maximum radius of the surface of the model, and for the minimum allowable m determine the nodal points of the cyclic control program. The conditions of the perimeters (1), the required number of tapes (2) and the lead-in (4) determine the complex geometric condition of continuity. If the first two terms in the expression of input (4) are obvious, the third term

depending on the sign determines the sequence of laying the tapes: “ahead of schedule”, i.e. with an increase in the angle of rotation by

(see Fig. 8), or "with a lag", i.e. decreasing the angle of rotation by

(see Fig. 9) per cycle of laying the tape layer.

и С

изображены фазовые углы поворота, соответствующие последним двум членам правой части выражения (4).In FIG. 8 and 9 with C

and C

phase rotation angles corresponding to the last two terms of the right-hand side of expression (4) are shown.

Then carry out the control cyclic winding on the technological mandrel. At the stage of determining the amendments, the boundaries of the wound sections are measured, the sections that do not meet the winding condition, as well as the unstable winding sections, are identified. Areas that do not meet the winding condition include areas on which, at the used angles (drawings) of the winding, the non-adhesion of the wound tapes to the surface of the mandrel is detected, i.e. the presence of "air wedges" between the ribbons of the layer and the surface. The areas of unstable winding include areas in which the slipping of tapes from (protrusions and ribs) surfaces is detected. On the considered mandrels of products with a complex shape of the surface of bodies of revolution and with a large ratio of the length to the perimeter of the cross section, to eliminate these situations, corrections are made according to the winding pattern for the input winding angle α and, accordingly, for the approach m with deviation from geodesy within the angle Φ in accordance with expression (5)
± Φ <f, (5) where f is the friction angle of the wound material and the surface.

 Subject to the winding condition, condition (5) is set as a stability condition.

At the stage of developing control programs for the winding of a sequence of layers, a set of cyclic control programs for winding with different (see Fig. 10) T ₁₁ , T ₁₂ , T ₁₃ , paths of the layouts, taking into account changes in the dimensions of the mandrel after the formation of the previous layers and with opposite directions of rotation, are developed winding pattern lines. At the stage of shaping the shell (see Fig. 11), the programs carry out spiral winding of alternating multidirectional layers. To do this, the next control program is entered into the control device of numerical program control (not shown in the drawings). If the next control program is designed for the right rotation of the winding pattern (see Fig. 3), then the folding heads 16 with the II axes for the holders 19 are installed around the II-II axes in the right position relative to the rods 19 and fixed in this position by the latches 18. Wound material 29 from bobbin drives 28, they are fed through rollers 31, tensioners 30, rollers 32 (tangent axes II in the right position of the folding heads) and then through the receiving rollers of the heads 16 and the folding rollers 24 of these heads are fixed to the mandrel 5. Separating substrate and from the bobbins 28, they are fed to receiving coils 27. During winding, under the influence of tension of the winding material, the heads 16 are installed around the axes II of the self-installation, and in the heads with the arrangement of the folding rollers 24 on the additional bushings 26, the self-installation is carried out simultaneously of the bushings 26 relative to the additional axes III-III self-installation.

 The trajectory of the folding rollers 24 is formed by the movement Z of the carriage 6, the rotation With shoulder strap 15, the radial movements X of the folding heads 16.

 After winding a layer or (depending on technological requirements) several layers in one direction (see Fig. 3) in order to exclude the appearance of "bulbs" in the areas of the ribs, a new control program is introduced into the control unit for numerical program control for winding the subsequent layer (layers) with rotation of the winding pattern to the other side C (see Fig. 4). Before this, the latches 18 are unlocked: the folding heads 16 are rotated by the II axes around the II-II axes to the left adjacent position relative to the rods 19 and fixed in such position by the latches 18. The wound material 29 from the drive bobbins 28 is secured through tensioners 30 and rollers 31, then refueling carried out through the receiving rollers of the heads 16 and the folding rollers 24 of these heads with fastening to the mandrel 5. Similarly, coils 27 are used to receive the separation substrate.

 The same executive bodies form the trajectory of the folding rollers 24, but the rotation of the shoulder strap 15 is carried out in the direction C (see FIG. 4), opposite to FIG. 3.

With stationary mandrels of low rigidity (see Fig. 2), they are stretched in the supports behind the trunnion by forces F ₁ -F ₂ and additionally supported by intermediate manipulators 11 provided with transverse supports 12, which are connected to the mandrel 5 and removed from it by actuators controlling the signals of the sensors 13 switched by the carriage 6 of the longitudinally movable winding device 7. As the layers of the shell are set, a cyclic control program is successively changed.

 When using flat, for example, rhomboid, bottoms, the reverse moment on the bottoms of the folding head is carried out at the same phase of rotation of the bottom plane, and the longitudinal displacement for the spiral winding cycle of each single tape within the layer is changed by a constant pitch proportional to the width of the tape used, and winding angle α, i.e. in this case, it is also possible to create a simplified winding control program.

 The multilayer shell obtained after winding and curing is subjected to further processing. To do this, in some designs the technological mandrel is removed and the technological bottoms are cut off, in other designs, the mandrel as a butt seal of the product includes a special bottom that remains with the product. The forms of butt sealing of the spar shells are very diverse.

PRI me R. Fully-wound spars of helicopter propeller blades were made (see Fig. 1). Length L8800 mm; in the transverse maximum size X 270 mm. The number of layers H 12; prepreg width l 15 mm; the distance between the middle lines of the prepreg h 12 mm; coefficient of relative overlap Δ b 0.154; set m 1. The total rotation angle of the winding pattern of the first layer C _Σ1 8300 ^о , the total rotation angle of the winding pattern of the last layer C _ΣH 8301l58 ^о , The winding angle at the entrance to the butt part L _in1 45 ^о ; winding angle at the entrance to the controlled technological bottom L _vnn 30 ^about . The greatest thickness of the typed laminate t 8 mm without gaskets; t 24 mm with gaskets. Fiberglass reinforcing material; binder EDT-10P; number of simultaneously working folding heads 4.

Curing: polymerization and pressure testing in an autoclave with electric heating and tsulag. The manufactured batch of side members passed dynamic tests according to a special program in the formed modes. Samples collected 100 · 10 ⁶ special reinforced cycles without destruction. The utilization of the material (KIM) ≈ 0.9.

The characteristic of the working area of the machine: the diameter of the working area D _r.z 500 mm; maximum distance between cartridges Z _m 10000 mm.

 Thus, the invention provides for the formation of cyclic spiral multi-folding winding of continuous stable layers of multilayer shells on the mandrels of products of complex shape of the surface of non-rotating bodies with a large ratio of length to perimeter of the cross section.

Claims (4)

1. The method of obtaining by winding layered products of complex shape, including the formation of a calculation model and the spatial path of the working body relative to the surface of the mandrel, determining corrections and shaping of the layers and curing, characterized in that the calculation model is formed in the form of a continuous set of reduced surfaces of the shape of bodies of revolution with perimeters in cross sections meeting the condition
B _{r . m} ≥ B _{t . oh}
where B _{r . m} is the perimeter of the cross section perpendicular to the longitudinal axis at the considered points of the calculation model;
B _{t. about} - the perimeter of the cross section perpendicular to the longitudinal axis at similar points of the technological mandrel,
at the same time, in the working area of the machine, the area of the paths of movement of the executive body is defined, which is limited by the generatrix constructed with the technological gap at the most radially remote points of the cross sections of the real, technological mandrel, then the total angle of rotation of the executive body is determined from the initially specified winding pattern for the tape laying cycle and replaced this angle to the nearest angle of rotation, based on the conditions of continuity and lead in accordance with the dependence

where C _Σ is the total angle of rotation per cycle according to the condition of continuity and continuity;
n is the number of full revolutions in the midline of the winding pattern per cycle;
m is a number indicating the winding pattern;

- the angle of rotation at the offset between adjacent ribbons of the layer;
l is the width of the tape;
a is the winding angle, i.e. the angle between the winding line and the meridian at the surface point in question;
R is the maximum surface radius of the calculation model,
at the selected minimum input m, determine and make corrections in accordance with C _Σ to the initially specified winding pattern, then determine the nodal points of the cyclic law of motion that defines the loop cycle of the layer with a deviation from geodesy within the limits ± Φ <f, where Φ is the deviation angle from geodesy, f is the angle of friction of the wound material and the surface, after which a layer is formed by a multi-folding spreader, then for each subsequent layer the overall dimensions of the wound shell are measured, new dimensions are introduced into the cyclic law n the movement of the forming layer, and the direction of rotation of the line of the winding pattern during the formation of the subsequent layer is changed to the opposite.  2. The method according to claim 1, characterized in that with a stationary mandrel of low rigidity, it is supported by intermediate manipulators equipped with transverse contractions, having actuators controlled by signals of sensors switched by a longitudinally movable winding device.  3. The method according to claim 1, characterized in that when forming multilayer shells that do not have high technical and technological requirements, the direction of rotation of the winding line is changed through several layers.  4. A mandrel for winding layered products of complex shape containing a portion of the main part of the product and technological bottoms, characterized in that between the portion of the main part of the product and the technological bottoms are mounted sections of smoothly connected linear transitions from the main part of the mandrel to the circular perimeter of the maximum perpendicular to its axis sections of the technological bottom with transition angles g proportional to the smallest winding angles α in these areas, and technological bottoms in their maximum sleep sections They are filled with sections of cylindrical or conical stabilization belts.

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