Method of fabricating a spar for a blade, a method of fabricating a blade, and a blade

Abstract

A method of fabricating a blade spar that includes transversely at least one arrangement. A pressure-side mold and a suction-side mold are defined for each arrangement that is to be fabricated. Each mold includes at least one removable slide and a base. Each slide is then removed from a mold and the tape segments of a hank are laid by a fiber-placement method on each mold. Each mold is closed by putting the slides into place on the mold. During a finalizing step, the molds are juxtaposed and the spar is heated.

Claims

1. A method of fabricating a spar of a blade from tapes of composite materials, the spar comprising transversely at least one arrangement, each arrangement suitable for being disposed about a root axis, the method comprising the following steps: during a preparation step, defining a pressure-side mold and a suction-side mold for each arrangement that is to be fabricated, each mold comprising a base extending longitudinally in the span direction of the spar and defining a laying surface that includes: a root zone having a root wall, the root wall forming two flanks; a connection zone presenting two sloping connection walls extending away from each other at a first angle and connected respectively to the two flanks; and a running zone presenting two running walls respectively extending the two connection walls; during a fabrication step, for each arrangement being subdivided into a pressure-side subassembly and a suction-side subassembly, each subassembly having a respective hank, each hank comprising a plurality of tape segments stacked on one another, each mold having at least one lateral removable slide defining the mold transversely by extending vertically from the base, and/or at least one longitudinal removable slide defining the mold longitudinally by extending vertically from the base: removing each slide from each mold; fabricating the pressure-side subassembly and the suction-side subassembly of an arrangement respectively on the pressure-side mold and on the suction-side mold corresponding to the arrangement, each subassembly being fabricated by stacking tape segments on the corresponding mold by a method of placing fibers with the help of a placement head, the placement head laying the segment on the laying surface of the mold; and closing each mold by putting each slide of the mold into place, and juxtaposing the molds in order to form a closed enclosure in which the subassemblies are to be found; and during a finalizing step, heating the spar within the juxtaposed molds.

2. The method according to claim 1, wherein at least one mold includes a removable core resting on a seat of the mold in order to embody the base, at least in part.

3. The method according to claim 1, wherein at least one mold has a base provided with a seat and a non-removable core of the spar, the non-removable core being constituted by a fastener bushing, a root wedge surrounding the fastener bushing and filler material of the spar.

4. The method according to claim 1, wherein, prior to juxtaposing the molds, at least one piece of internal equipment of the spar is placed in at least one mold.

5. The method according to claim 1, wherein the spar has a trailing-edge arrangement and a leading-edge arrangement, and: during the preparation step, a leading-edge pressure-side mold and a leading-edge suction-side mold and a trailing-edge pressure-side mold and a trailing-edge suction-side mold are defined; and during the finalizing step, the leading-edge pressure-side mold is juxtaposed laterally with the trailing-edge pressure-side mold, the leading-edge suction-side mold is juxtaposed laterally with the trailing-edge suction-side mold, the trailing-edge pressure-side mold is juxtaposed in elevation with the trailing-edge suction-side mold, and the leading-edge suction-side mold is juxtaposed in elevation with the leading-edge pressure-side mold.

6. The method according to claim 1, wherein the root axis is a vertical axis substantially orthogonal to a plane in which the spar extends in span, and the sloping connecting walls extend away from each other at a second angle, more than the first angle, on going away from the root zone.

7. The method according to claim 1, wherein the root axis is a vertical axis substantially orthogonal to a plane in which the spar extends in span, and during fabrication of a subassembly, the placement head winds each tape segment of the subassembly around a root axis by laying the segment on the laying surface of the mold.

8. The method according to claim 1, wherein the connection zone presenting two sloping connection walls forms a portion of an upside down V-shape.

9. The method according to claim 1, wherein the connection zone presenting two sloping connection walls forms a substantially upside down V-shape.

10. The method according to claim 1, wherein the connection zone presenting two sloping connection walls forms a truncated upside down V-shape.

11. The method according to claim 1, wherein the connection zone presenting two sloping connection walls forms an upside down V-shape.

12. The method according to claim 1, wherein tape segments are U-shaped.

13. A method of fabricating a blade, the method comprising the following steps: fabricating a spar by applying the method according to claim 1; fabricating an overall mold for the blade; arranging the spar in the overall mold; and arranging the overall mold in a heater for finalizing the blade by heating it.

14. A blade having at least one spar, each spar including an arrangement suitable for being disposed about a fastener bushing, each arrangement comprising a pressure-side subassembly and a suction-side subassembly, each arrangement extending spanwise to comprise in succession a root zone at the fastener bushing, a connection zone, and then a running zone, wherein a cross-section of each arrangement in the connection zone is substantially X-shaped, the pressure-side subassembly having a substantially upside-down V-shape and the suction-side subassembly having a substantially rightway-up V-shape in the connection zone.

15. The blade according to claim 14, wherein the fastener bushing has a root axis substantially orthogonal to a plane in which the spar extends spanwise, and each root section of the arrangement in the root zone comprises at least one rectangular slab extending lengthwise in elevation.

16. The blade according to claim 15, wherein the root axis is a vertical axis substantially orthogonal to a plane in which the spar extends spanwise, and each running section of the arrangement in the running zone comprises at least one slab extending transversely lengthwise.

17. A blade having a spar including a first arrangement suitable for being disposed about a fastener bushing, the first arrangement comprising a pressure-side subassembly and a suction-side subassembly, the first arrangement extending spanwise to comprise a root zone at the fastener bushing, a running zone, and a connection zone extending between and connecting the root zone and the running zone, the connection zone having a substantially X-shaped cross-section, the pressure-side subassembly having a shape having at least a portion of an upside-down V and the suction-side subassembly having a shape having at least a portion of a substantially rightway-up V in the connection section.

18. The blade according to claim 17, wherein the fastener bushing has a root axis substantially orthogonal to a plane in which the spar extends spanwise, and a root section of the first arrangement in the root zone comprises at least one rectangular slab extending lengthwise in elevation.

19. The blade according to claim 18, wherein the root axis is a vertical axis substantially orthogonal to a plane in which the spar extends spanwise, and each running section of the arrangement in the running zone comprises at least one slab extending transversely lengthwise.

20. The blade according to claim 17, wherein the spar includes a second arrangement suitable for being disposed about a fastener bushing, the second arrangement comprising a pressure-side subassembly and a suction-side subassembly, the second arrangement extending spanwise to comprise a root zone at the fastener bushing, a running zone, and a connection zone extending between and connecting the root zone and the running zone, the connection zone having a substantially X-shaped cross-section, the pressure-side subassembly having a shape having at least a portion of an upside-down V and the suction-side subassembly having a shape having at least a portion a substantially rightway-up V in the connection section.

21. The blade according to claim 17, wherein the connection zone presents two sloping connection walls forming a portion of an upside down V-shape.

22. The blade according to claim 17, wherein the connection zone presents two sloping connection walls forming a substantially upside down V-shape.

23. The blade according to claim 17, wherein the connection zone presents two sloping connection walls forming a truncated upside down V-shape.

24. The blade according to claim 17, wherein the connection zone presents two sloping connection walls forming an upside down V-shape.

Description

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

(1) The invention and its advantages appear in greater detail from the context of the following description of examples given by way of illustration and with reference to the accompanying figures, in which:

(2) FIG. 1 is a diagrammatic plan view of a blade having a vertical root axis obtained by applying the method of the invention;

(3) FIGS. 2 to 4 are diagrammatic cross-section views of said blade;

(4) FIG. 5 is a diagrammatic view of a fiber-placement system of the invention for putting fibers into place;

(5) FIG. 6 is a diagram showing a spar and section views of a mold for fabricating said spar;

(6) FIG. 7 is a diagram showing the slides of a mold;

(7) FIG. 8 is a diagram explaining the juxtapositioning of molds;

(8) FIG. 9 is a diagram explaining the fabrication of a blade; and

(9) FIG. 10 is a plan view and a section view of a blade provided with a horizontal root axis obtained by applying the method of the invention.

DETAILED DESCRIPTION OF THE INVENTION

(10) Elements present in more than one of the figures are given the same references in each of them.

(11) It should be observed that some of the figures show three mutually orthogonal directions X, Y, and Z.

(12) The first direction X is said to be longitudinal. The term longitudinal relates to any direction parallel to the first direction X.

(13) The second direction Y is said to be transverse. The term transverse relates to any direction parallel to the second direction Y. The chord of the fabricated blade extends transversely, whereas the span of the blade extends longitudinally.

(14) Finally, the third direction Z is said to be in elevation. The term in elevation relates to any direction parallel to the third direction Z.

(15) FIG. 1 shows a blade 1 fabricated by applying the method of the invention.

(16) The blade 1 has an outer skin 2 inside which there extends a spar 5.

(17) The spar 5 thus extends longitudinally along the span of the blade 1 in a plane P1 that extends spanwise, it extends transversely along the chords of the blade 1, and it extends in elevation along the thickness of the blade 1.

(18) Each section of the blade 1 is thus a cross-section parallel to the second direction Y and to the third direction Z.

(19) The spar 5 surrounds at least one fastener bushing 41. Thus, the spar 5 has one arrangement 10, 15 per fastener bushing. Each arrangement is then wound around a root axis AX1, AX2 of symmetry of a respective fastener bushing 41. In the embodiment of FIG. 1, such a root axis is a vertical axis AX1, AX2 that is substantially orthogonal to the plane P1 extending spanwise.

(20) Nevertheless, and with reference to FIG. 10, the root axis could be a horizontal axis lying substantially in the spanwise plane P1.

(21) With reference to FIG. 1, the blade may have two fastener bushings 41. Under such circumstances, the spar 5 has one arrangement that is referred to for convenience as the leading-edge arrangement 10 that surrounds the fastener bushing closer to the leading edge of the blade by being wound around a first root axis AX1. The spar 5 also has a second arrangement referred to as the trailing-edge arrangement 15 that surrounds the fastener bushing closer to the trailing edge of the blade by being wound around a second root axis AX2.

(22) FIGS. 2 to 4 show sections of the blade respectively in a root zone Z1, a connection zone Z2, and a running zone Z3.

(23) By way of example, each arrangement may comprise a pressure-side subassembly 11 and a suction-side subassembly 12. Each subassembly may also comprise a single hank.

(24) Consequently, each arrangement possibly possesses a single pressure-side hank and a single suction-side hank. Under such circumstances, the leading-edge arrangement has a hank referred to as the leading-edge pressure-side hank 81 and a hank referred to as the leading-edge suction-side hank 82. Likewise, the trailing-edge arrangement comprises a trailing-edge pressure-side hank 83 and a trailing-edge suction-side hank 84.

(25) FIGS. 1 to 4 explain a first embodiment.

(26) With reference to FIG. 2, a section of a hank 81, 82, 83, 84 of an arrangement is substantially in the form of two rectangles in the root zone Z1. The length of each rectangle extends substantially parallel to the corresponding root axis.

(27) Each hank comprises a stack of tape segments 6, 7. Nevertheless, FIG. 1 shows only one hank in order to avoid being pointlessly overcrowded.

(28) In contrast, and with reference to FIG. 3, each section of an arrangement may have substantially a >< shape like an hourglass in the connection zone Z2, this hourglass shape flattening on going away from the root zone.

(29) Under such circumstances, each hank 81, 82, 83, 84 of an arrangement is substantially V-shaped in the running zone Z3. This V-shape then tends to present a point 81, 82, 83, 84 directed towards the center of the spar. In the section shown in FIG. 3, this V-shape is truncated so that it does not present the point of the V-shape.

(30) Finally, and with reference to FIG. 4, each section of a hank 81, 82, 83, 84 of an arrangement has a substantially horizontal flat shape in the running zone Z3.

(31) Furthermore, the leading-edge arrangement is solid, presenting a leading-edge pressure-side hank 81 juxtaposed with a leading-edge suction-side hank 82. In contrast, the trailing-edge arrangement 15 has a trailing-edge pressure-side hank 83 that is vertically spaced apart from a trailing-edge suction-side hank 84.

(32) The section of the spar in the running zone Z3 is then C-shaped.

(33) In the embodiment of FIG. 10, each section of a hank 81, 82, 83, 84 of an arrangement has a substantially vertical flattened shape in the running zone Z3.

(34) Such a spar 5 and such a blade 1 can be fabricated in automatic manner by applying the method of the invention.

(35) The method seeks to fabricate the spar from at least one tape of composite materials using a fiber-placement head.

(36) The tape may have reinforcement in the form of fibers and a matrix in the form of resin.

(37) With reference to FIG. 5, the method makes use of a system having a robot 51. The robot 51 has an articulated arm 52 mounted on a carriage 54 that slides on rails 55. Furthermore, the robot 51 has a fiber-placement head 53 enabling segments of a tape of composite materials to be laid on a support. Such a segment is referred to for convenience as a tape segment.

(38) The placement head then has at least six degrees of freedom, namely three degrees of freedom to move in translation and three degrees of freedom to move in rotation.

(39) Furthermore, the carriage gives the fiber-placement head 53 the capacity to move several meters along an axis corresponding to the span of the blade. The fiber-placement head 53 can be used, for example, to lay a tape having a width of about 20 millimeters (mm).

(40) The robot 51 is controlled by a controller so that the placement head lays tape along stored paths. The controller comprises a processor unit having program execution means and a memory, the program execution means executing instructions stored in the form of lines of code in the memory in order to apply the method of the invention. By way of example, the processor unit is a computer.

(41) This system then enables a blade to be fabricated.

(42) In the method, the spar is fabricated by performing a fiber-placement method with the help of the robot 51.

(43) Under such circumstances, during a preparation step SPT1, a manufacturer defines one mold 21, 22, 31, 32 per hank 8.

(44) Consequently, the manufacturer defines the shape of a pressure-side mold 22, 32 and a suction-side mold 21, 31 per arrangement 10, 15 during the preparation step.

(45) In order to make the FIG. 1 blade, the manufacturer can then define a leading-edge pressure-side mold 22 and a leading-edge suction-side mold 21 and also a trailing-edge pressure-side mold 32 and a trailing-edge suction-side mold 31.

(46) Each mold 21, 22, 31, 32 includes a respective base 23, 24, 33, 34, e.g. standing on a bench.

(47) Furthermore, each mold 21, 22, 31, 32 may include at least one slide referred to as a lateral slide 25, 26, 35, 36. Each lateral slide defines the corresponding mold 21, 22, 31, 32 transversely by extending vertically from the base 23, 24, 33, 34. A lateral slide may extend longitudinally part of the way along the base or it may extend along the entire length of the base.

(48) Furthermore, each mold may include at least one slide referred to as a longitudinal slide 37, 38, 39 and 40 that defines the mold longitudinally by extending vertically from the base.

(49) The slides are removable so as to enable the placement head to lay segments of tape.

(50) Under such circumstances, and with reference to FIG. 6, each mold defines a laying surface onto which segments of tape are to be stacked. FIG. 6 shows more specifically the first embodiment of FIGS. 1 to 4. Nevertheless, its teaching can be transposed to the second embodiment.

(51) In order to facilitate representing a mold, FIG. 6 shows in its right-hand half a spar 5, and in its left-hand half four sections of a mold, and in particular of a trailing-edge pressure-side mold.

(52) Thus, each mold presents, in the root zone Z1, a substantially vertical root wall 61 that is C-shaped.

(53) The root wall then forms a rounded end wall 62 that is extended by two vertical flanks 63.

(54) In the connection zone Z2, each mold presents two sloping connection walls 64, 65. The connection walls tend to form a V-shape, which may possibly be truncated, with the point of the V-shape being omitted. Each connection wall 64, 65 extends a vertical flank 63.

(55) This V-shape flattens on going away from the root zone Z1.

(56) Thus, in a first section Z2 close to the root zone Z1, the two connection walls are contained in planes that make a highly acute angle relative to each other. These two connection walls need not meet so as to form a truncated V-shape.

(57) In contrast, in a second section Z2 further away from the root zone Z1, the two connection walls lie in planes that make an obtuse angle relative to each other, for example. These two connection walls may then meet so as to form a V-shape that is not truncated.

(58) In the running zone Z3, each section presents two substantially horizontal running walls 66, 67 that respectively extend the two connection walls 64, 65. The two running walls 66, 67 may be juxtaposed transversely.

(59) In order to embody the laying surface, the base of a mold may comprise a seat 72 carrying a core 71.

(60) In the root zone and in the connection zone, the core presents the end wall, the root walls, and the connection walls.

(61) In contrast, the seat may comprise the running walls, for example.

(62) The core may be a removable core that is separated from the spar once it has been fabricated.

(63) Conversely, the core could be non-removable and comprise elements that will constitute the blade.

(64) Thus, the core may comprise a fastener bushing 41, a root wedge 42 surrounding the fastener bushing, and filler material 43 of the spar.

(65) In the embodiment of FIG. 6, each mold presents a root wall in the root zone Z1.

(66) The root wall forms two vertical flanks 61 and 63 that are juxtaposed. The flanks are arcuate in order to surround the root axis in part.

(67) In the connection zone Z2, each mold presents two connection walls 64, 65. The connection walls tend to form a V-shape, which may possibly be truncated having the point of the V-shape omitted. Each connection wall extends a horizontal flank.

(68) This V-shape flattens out on going away from the root zone Z1.

(69) In the running zone Z3, each section presents two substantially horizontal running walls 66, 67 respectively extending the two connection walls. The two running walls are offset transversely.

(70) In the method of fabrication, an operator fabricates the subassemblies of the spar one after another as follows.

(71) In order to fabricate the hank of a subassembly, the operator removes the slides from the mold during a fabrication step.

(72) The operator then puts the robot 51 into operation.

(73) The absence of slides then enables the fiber-placement head to lay the tape segments on the laying surface of the mold.

(74) The fiber-placement head 53 thus winds each tape segment of the subassembly around a root axis AX1, AX2 of the mold, laying said segment on the laying surface of the mold.

(75) The fiber-placement head may optionally wind each tape segment of the subassembly around a vertical axis so as to describe a U-shape. The fiber-placement head then lays a segment on a first running wall, a first connection wall, the root wall, a second connection wall, and a second running wall of the mold.

(76) At the end of this operation of laying tape segments, and with reference to FIG. 7, the operator then closes the mold by arranging the slides of the mold. For example, at least one slide is secured to a base by reversible fastener means 27, such as screw-fastener means or interfitting means, in particular.

(77) It should be observed that, where appropriate, a slide may be common to two molds. For example, a longitudinal slide may close each of two distinct molds in part.

(78) Optionally, internal equipment of the spar is inserted into the mold. By way of example, such internal equipment may include static and dynamic blade balancing boxes, together with dynamic matching boxes or masses and masses or counterweights for setting the center of gravity along a chord.

(79) With reference to FIG. 8, the operator also assembles the molds to one another. At the end of this assembly operation, the molds form a closed enclosure in which the hanks of the spar are held.

(80) For example, the leading edge pressure-side mold 22 is secured to the trailing-edge pressure-side mold 32. In addition, the leading-edge suction-side mold 21 is secured laterally to the trailing-edge suction-side mold 31.

(81) In addition, the trailing-edge pressure-side mold 32 is secured in elevation to the trailing-edge suction-side mold 31, with the leading-edge suction-side mold 21 being secured in elevation to the leading-edge pressure-side mold 22.

(82) The spar is then heated in order to be polymerized if its resin is of the thermosetting type, or to be consolidated if the resin is of the thermoplastic type.

(83) In order to fabricate the FIG. 1 blade, and with reference to FIG. 9, an operator also prepares an overall mold 95 of the blade to be fabricated.

(84) The operator then places the finished spar 5 in the overall mold 95.

(85) The overall mold 95 is then placed in heater means 96 in order to polymerize or consolidate the blade 1.

(86) Thus, the method makes it possible to obtain a blade having at least one fastener bushing and a spar, the spar having one arrangement per fastener bushing.

(87) As shown in FIG. 2, each section referred to as root section of an arrangement in the root zone Z1 may include at least one substantially rectangular slab extending in elevation along its length. In particular, the arrangement has two mutually parallel slabs arranged on either side of the fastener bushing.

(88) As shown in FIG. 3, each section referred to as connection section of said arrangement in the connection zone Z2 is X-shaped. Under such circumstances, a pressure-side subassembly of the arrangement has an upside-down V-shape, while a suction-side subassembly has a rightway-up V-shape in this connection section.

(89) Finally, and with reference to FIG. 4, each running section of said arrangement in the running zone Z3 comprises at least one slab extending transversely along its length.

(90) In particular, the arrangement has two substantially horizontal slabs that are juxtaposed or offset in elevation.

(91) Naturally, the present invention may be subjected to numerous variants as to its implementation. Although several embodiments are described, it will readily be understood that it is not conceivable to identify exhaustively all possible embodiments. It is naturally possible to envisage replacing any of the means described by equivalent means without going beyond the ambit of the present invention.