Blower module impeller and jet turbine engine equipped with such an impeller

Description

Technical Field

[0001] The present invention relates to a turbojet fan module wheel and, more particularly, to a fan module outlet rectifier wheel, and to a turbojet engine equipped with such a wheel. A fan module outlet rectifier wheel is also known to those skilled in the art by the English term Out / et Guide Vane or the acronym OGV. Such a wheel is fixed, and therefore does not rotate around the axis of the turbojet unlike a fan wheel.

[0002] It should be noted that the term "turbojet" designates a gas turbine engine providing, by reaction to the high-speed ejection of hot gases, the thrust necessary for propulsion. Prior art

[0003] The blades of known fan module outlet stator wheels may be made of fiber-reinforced organic matrix composite material. The assembly of such blades with the rest of the wheel generally uses at least one bolt directly engaged in a portion of the blade, for example the root and / or the head of the blade, and is generally not optimized in terms of vibration or impact resistance. Furthermore, the formation of assembly holes in the composite material weakens the blade with local stress concentrations that are sometimes very harmful. There is therefore a need in this regard. Furthermore, a similar need has also been observed with the fan blades of a turbojet fan module. EP 3 798 418 A1 describes a woven composite gas turbine blade and a method for manufacturing such a blade. EP 2 706 240 A2 describes a set of guide vanes.EP 2 674 577 A2 describes a blade attachment assembly for a turbomachine and corresponding turbomachine. Statement of the invention

[0004] One aspect of the invention relates to a turbojet fan module wheel, having an axial direction, a radial direction and a circumferential direction, an upstream face and a downstream face, the wheel comprising a plurality of blades made of fiber-reinforced organic matrix composite material, each blade having a root assembled with a base separate from the bases of the other blades, each base having a groove extending axially and opening on the upstream face side and / or on the downstream face side, each root cooperating by axial interlocking by complementarity of shapes, for example in dovetail shapes, with the groove of the base, whereby the root is retained on the base in the radial and circumferential directions, and each base cooperates with at least one part configured to axially block the root within the groove of the base, whereby the root is retained in the axial direction.

[0005] Generally speaking, the axial direction corresponds to the direction of the axis of the stator wheel, and a radial direction is a direction perpendicular to the axial direction. The circumferential (or azimuthal) direction corresponds to the direction describing a ring around the axial direction. The three directions axial, radial and circumferential correspond respectively to the directions defined by the coast, the radius and the angle in a cylindrical coordinate system. Furthermore, upstream and downstream are defined relative to the normal flow direction of the fluid (from upstream to downstream) through the stator wheel (and more generally through the turbojet).

[0006] It is understood that each blade is assembled with its own base. In other words, there are as many bases as there are blades, each base receiving a single blade (distinct from the blades of the other bases). In other words, there is one base per blade. Also, subsequently, and unless otherwise indicated, the description relating to all or part of the assembly system of a blade (e.g. a blade, a base and at least one part configured to axially block the root) applies to all or part, respectively, of each of the assembly systems of all the other blades.

[0007] The foot and the groove can have any shape allowing axial interlocking by complementary shape, for example a dovetail shape, a clover shape, etc. The groove can be axially open only on the upstream face side (i.e. axially closed on the downstream face side), only on the downstream face side (i.e. axially closed on the upstream face side), or axially open on the upstream face side and on the downstream face side. This last configuration has the advantage of facilitating the assembly of the foot with the groove (several fitting directions being possible).

[0008] The base may cooperate with a single, two, or more than two part(s) configured to axially lock the foot within the groove of the base. This or these part(s) may be specific to each blade, or be common to two, more than two, or all the blades.

[0009] Such an assembly system provides better vibration resistance and better bending stiffness. Furthermore, such an assembly does not involve any drilling in the blade, thereby avoiding weakening it. This also reduces the mass of the assembly by omitting the blade fixing bolts of the prior art. The reduced number of parts required for assembly also meets the mass reduction requirement. For example, the assembly system for each blade comprises only three elements, namely the blade, the base and a single part configured to axially lock the root within the groove of the base.

[0010] In some embodiments, the blades are variable pitch, each of the bases being mounted on a single part, distinct from the single parts of the other bases, configured to axially lock the root within the groove of the base, each single part being configured to pivot about the radial direction.

[0011] It is understood that each base cooperates with a single part configured to axially block the root within the groove, which is specific to it. In other words, there are as many single parts as there are bases, each single part cooperating with a single base (distinct from the bases of the other single parts). In other words, there is a single part per base. The single part makes it possible on the one hand to axially block the root within the groove, and on the other hand to pivot the base, and therefore the blade, around the radial direction, whereby the setting (i.e. the angle formed by a chord of the blade with the incident air flow) of the blade is variable. The single part can pivot around the radial direction by any means otherwise known to those skilled in the art.

[0012] In some embodiments, each single piece includes a cavity receiving at least a portion of the base, the walls of the cavity blocking the groove on the upstream face side and on the downstream face side.

[0013] The single piece therefore blocks the foot axially within the groove in the two opposite directions, namely from upstream to downstream and from downstream to upstream.

[0014] In some embodiments, each base includes a flange extending in axial and circumferential directions, the base being secured to the single piece via the flange.

[0015] For example, the flange is an annular flange extending in a plane defined by the axial and circumferential directions. For example, the flange has through holes extending in the radial direction, for example counterbored holes, for fixing the flange using screws. Such a structure makes it possible to form a wall as continuous and smooth as possible, avoiding or limiting, in operation, the formation of aerodynamic drag in the air flow.

[0016] In some embodiments, the blades are fixed-pitch, each base cooperating with an upstream part configured to axially block the root within the groove of the base towards the side of the upstream face and a downstream part configured to axially block the root within the groove of the base towards the side of the downstream face.

[0017] The upstream part allows the blade to be locked in the axial direction, from downstream to upstream. The downstream part allows the blade to be locked in the axial direction, from upstream to downstream.

[0018] For example, the upstream and downstream parts may be specific to each blade or common to several blades. For example, the upstream and downstream parts may be portions of the impeller housing or flanges of the impeller hub. The upstream and downstream parts may be fixed to the base(s), but not necessarily. The bases are immobile relative to the rest of the impeller, whereby the blades are fixed (i.e. cannot rotate around a radial direction).

[0019] In some embodiments, the root of each blade and the groove of each base have the same axial length.

[0020] This ensures immediate contact between the root of each blade and the part(s) configured to axially lock the root within the groove of the base. This reduces the number of parts required and the mass while improving vibration resistance and bending stiffness.

[0021] In some embodiments, the turbojet fan module wheel as briefly discussed above is a turbojet fan module outlet stator wheel. The blades of the stator wheel are referred to as stator blades.

[0022] In certain embodiments where the wheel is a turbojet fan module output rectifier wheel, the blades are fixed pitch and each blade has a head assembled with a second base separate from the second bases of the other blades, each second base having a groove extending axially and opening on the upstream face side and / or on the downstream face side, each head cooperating by axial interlocking by complementarity of shapes, for example in dovetail shapes, with the groove of the second base, by which the head is retained on the second base in the radial and circumferential directions, and each second base cooperates with at least one second part configured to axially block the head within the groove of the second base, by which the head is retained in the axial direction.

[0023] In other words, when the blades are fixed-pitch, they can also be held by the head using a system similar to the system holding them by the root. The groove of each second base can be axially open only on the upstream face side (i.e. axially closed on the downstream face side), only on the downstream face side (i.e. axially closed on the upstream face side), or axially open on the upstream face side and on the downstream face side. This last configuration has the advantage of facilitating the assembly of the head with the second groove (several fitting directions being possible). For example, the groove of the base and the groove of the second base can both be open on one and the same side, but not necessarily.

[0024] In some embodiments, each second base cooperates with a second upstream part configured to axially lock the head within the groove of the second base towards the side of the upstream face and a second downstream part configured to axially lock the head within the groove of the second base towards the side of the downstream face.

[0025] The second upstream part allows the blade to be locked in the axial direction, from downstream to upstream. The second downstream part allows the blade to be locked in the axial direction, from upstream to downstream.

[0026] For example, the second upstream part and the second downstream part may be specific to each blade or common to several blades. For example, the second upstream part and the second downstream part may be portions of the impeller housing. The second upstream and downstream parts may be attached to the second base(s), but not necessarily.

[0027] In some embodiments, the tip of each blade and the groove of each second base have the same axial length.

[0028] This ensures immediate contact between the head of each blade and the second part(s) configured to axially lock the head within the groove of the second base. This reduces the number of parts required and the mass while improving vibration resistance and bending stiffness.

[0029] In some embodiments, the turbojet fan module wheel as briefly discussed above is a turbojet fan wheel.

[0030] A second aspect of the invention relates to a turbojet engine comprising a turbojet engine fan module wheel according to any one of the embodiments described herein. Brief description of the drawings

[0031] The object of the present disclosure and its advantages will be better understood upon reading the detailed description given below of the aspects of the invention and of different embodiments given as non-limiting examples. This description refers to the appended pages of figures, in which: [ Fig. 1 ] There figure 1 represents a partial sectional view of a turbojet engine, [ Fig. 2 ] There figure 2 represents an exploded view of an assembly system for a blade of a fan module wheel of the turbojet engine of the figure 1 , for the case of a variable pitch blade, and [ Fig. 3 ] There figure 3 represents an exploded view of the assembly system of a blade of an outlet rectifier wheel of the fan module of the turbojet engine of the figure 1 , for the case of a fixed-pitch blade; [ Fig. 4 ] There figure 4 represents a view of another assembly system of a blade of an outlet rectifier wheel of the fan module of the turbojet of the figure 1 , [ Fig. 5 ] There figure 5 represents an exploded view of the assembly system of the figure 4 ; [ Fig. 6 ] There figure 6 represents an enlarged partial view showing the position of a shim between a blade root and the groove of a base; [ Fig. 7 ] There figure 7 represents a possible embodiment of a shim that can be used in the systems of figures 2 à 6 . Description of the embodiments

[0032] There figure 1 schematically represents a turbojet engine 100 comprising a fan module 10. In this example, the turbojet engine 100 is of the double-spool, double-flow type, but any other type of turbojet engine comprising a fan module is possible.

[0033] The fan module 10 has a fan (or blower) 12 and an outlet rectifier wheel 14. The fan 12 rotates around the axis A while the rectifier wheel 14 does not rotate around the axis A. The axis A corresponds to the axis of the turbojet 100, which is coincident with the axis of the fan 12 and the axis of the rectifier wheel 14, and defines the axial direction X. The wheel 14 has an axial direction X, a radial direction R, a circumferential direction C, an upstream face FAM and a downstream face FAV.

[0034] There figure 2 represents the system for mounting a blade within a first embodiment of the output rectifier wheel 14, within which the blades 16 are variable pitch. It will be noted, however, that the blade mounting system of the figure 2 can also be applied to the blades of the fan wheel 12 of the figure 1 . There figure 2 represents a single straightening blade 16, but this system is the same for all the straightening blades 16 of the wheel 14 according to the first embodiment. It is noted that the aerodynamic profile 13 of the blade 16 shown on the figure 2 is purely schematic, and does not correspond to a real profile.

[0035] The blades 16 are made of fiber-reinforced organic matrix composite material, for example carbon fibers woven in a three-dimensional weave. Each blade 16 has a root 16A assembled with a base 18 separate from the bases of the other blades of the wheel 14. The base 18 has a groove 18A extending axially and opening on the side of the upstream face FAM and on the side of the downstream face FAV. The root 16A cooperates by axial interlocking by complementary shapes with the groove 18A of the base 18 (complementarity between the external surface of the root 16A and the internal surface of the groove 8A). In this example, the root 16A and the groove 18A have a cross-section to the interlocking direction (i.e. to the axial direction X) in the shape of a dovetail (however, other complementary shapes not shown here are conceivable). This allows the foot 16A to be retained within the base 18 in the radial R and circumferential C directions.In this example, the base 18 cooperates with a single part 20 configured to axially block the root 16A within the groove 18A of the base 18. This allows the root 16A to be retained in the axial direction X within the groove 18A. In particular, the single part 20 blocks the root 16A in the direction from the upstream face FAM to the downstream face FAV and in the direction from the downstream face FAV to the upstream face FAM. The single part 20 (pivot part) is configured to pivot about the radial direction R, by any means otherwise known to those skilled in the art, whereby the pitch of the blade is variable.

[0036] The single part 20 comprises a cavity 20A receiving at least one portion 18B of the base 18, the walls of the part which delimit the cavity 20A blocking the groove 18A on the side of the upstream face FAM and on the side of the downstream face FAV. The axial length L1 of the root 16A is equal to the axial length L2 of the groove 18A. It will be noted that the root 16A of the blade has, at its two opposite axial ends, two faces called upstream and downstream whose surfaces are shaped so as to be complementary, locally, to the internal surface of the walls of the part 20 which define the cavity 20A, and in particular at the location where these walls axially obstruct the groove.

[0037] More particularly, in this example, the part 18B of the base 18 has a cylindrical shape with an axis parallel to the radial direction R, in which the groove 18A is formed. The groove 18A is open and passes right through, perpendicular to the axis of the cylindrical shape, the part 18B. The cavity 20A of the single part 20 also has a cylindrical shape, adjusted to the part 18B, so as to be able to fit the part 18B into the cavity 20B with a minimum of play. For example, the surfaces of the two upstream and downstream faces of the foot 16A are cylindrical (radiated) and these cylindrical surfaces are concentric with the cylindrical shape of the cavity 20A of the part 20 and of the same radius. The base 18 further has an annular flange or collar 18C extending in the axial X and circumferential C directions, the base 18 being fixed to the single part 20 via this flange 18C.The annular flange 18C is more particularly separated into two parts by an axial central slot located directly above the groove 18A and which opens into the latter. In this example, the single part 20 also has an annular flange or collar 20B configured to cooperate with the flange 18C. For example, the base 18 is fixed to the single part 20 using screws 22. For example, the cavity 20A is formed in a cylindrical portion 20C with an axis parallel to the radial direction R.

[0038] There figure 3 represents the system for mounting a blade within a second embodiment of the output rectifier wheel 14, within which the blades 16' are fixed-pitch. The figure 3 represents a single 16' straightening blade, but this system is the same for all the 16' straightening blades of the wheel 14 according to the second embodiment. It is noted that the aerodynamic profile 13' of the 16' blade shown on the figure 3 is purely schematic, and does not correspond to a real profile.

[0039] The blades 16' are made of fiber-reinforced organic matrix composite material. Each blade 16' has a root 16'A assembled with a base (or first base) 18' distinct from the bases of the other blades of the wheel 14 and a head 16'B assembled with a second base 24 distinct from the second bases of the other blades of the wheel 14.

[0040] The base 18' has a groove 18'A extending axially and opening on the side of the upstream face FAM and on the side of the downstream face FAV. The foot 16'A cooperates by axial interlocking by complementary shapes with the groove 18'A of the base 18'. In this example, the foot 16'A and the groove 18'A have a cross-section to the interlocking direction (i.e. to the axial direction X) in the shape of a dovetail (however, other complementary shapes not shown here are conceivable). This allows the foot 16'A to be retained within the base 18' in the radial directions R and circumferential directions C. The axial length L3 of the foot 16'A is equal to the axial length L4 of the groove 18'A. For example, the 18' base has a substantially parallelepiped shape, and can be formed from two separate pieces as shown in the figure 3 , or of a single piece.

[0041] In this example, the base 18' cooperates with an upstream part 26 configured to axially block the root 16'A within the groove 18'A of the base 18' in the axial direction in the direction oriented from the downstream face FAV towards the side of the upstream face FAM. The base 18' also cooperates with a downstream part 28 configured to axially block the root 16'A within the groove 18'A of the base 18' in the axial direction in the direction oriented from the upstream face FAM towards the side of the downstream face FAV. This allows the root 16'A to be retained in the axial direction X within the groove 18'A. In this example, the upstream part 26 and the downstream part 28 are specific to the blade 16', i.e. there are as many upstream parts 26 and second downstream parts 28 as there are blades 16'. In this example, the upstream part 26 and the downstream part 28 are portions of the casing of the wheel 14.

[0042] The second base 24 has a groove 24A extending axially and opening on the side of the upstream face FAM and on the side of the downstream face FAV. The head 16'B cooperates by axial interlocking by complementarity of shapes with the groove 24A of the second base 24. In this example, the head 16'B and the groove 24A have a cross-section to the interlocking direction (i.e. axial direction X) in the shape of a dovetail. This allows the head 16'B to be retained within the second base 24 in the radial direction R and circumferential direction C. The axial length L5 of the head 16'B is equal to the axial length L6 of the groove 24A. For example, the second base 24 has a substantially parallelepiped shape, and can be formed of two separate parts as shown in the figure 3 , or of a single piece.

[0043] In this example, the second base 24 cooperates with a second upstream part 30 configured to axially block the head 16'B within the groove 24A of the second base 24 in the axial direction in the direction oriented from the downstream face FAV towards the side of the upstream face FAM. The second base 24 also cooperates with a second downstream part 32 configured to axially block the head 16'B within the groove 24A of the base 24 in the axial direction in the direction oriented from the upstream face FAM towards the side of the downstream face FAV. This allows the head 16'B to be retained in the axial direction X within the groove 24A. In this example, the second upstream part 30 and the second downstream part 32 are specific to the blade 16', i.e. there are as many second upstream parts 30 and second downstream parts 32 as there are blades 16'. In this example, the second upstream part 30 and the second downstream part 32 are portions of the casing of the wheel 14.

[0044] THE figures 4 à 6 illustrate an embodiment which takes up that of the figure 2 and which adds a similar blocking for the head of the blade with elements similar or identical to those described for the root of the blade. Thus, on the figure 4 , the root 16"A of the blade 16" is retained radially and circumferentially in the groove 18"A of the base 18" and the root is axially blocked by means of the locking piece 20" (pivot piece). Similarly, the head 16"B of the blade 16" is retained radially and circumferentially in the groove 24"A of the second base 24" and the root 16"B is axially blocked by means of the second locking piece 30" (pivot piece).

[0045] There figure 5 which is an exploded view of the assembled system of the figure 4 shows the different constituent elements of this system including two shims (optional) C1, C2 which are each shown between the bottom of the groove of the corresponding 18" and 24" base and the underside or bottom of the blade root or the top of the blade head. These shims are used in particular to wedge the blade root (blade head) in position in the axial groove of the base, to facilitate disassembly and also serve as a wear part. It should be noted that the locking parts (pivot parts) illustrated on the figures 4 And 5 have been shown with a base. However, in a variant not shown, a base is not necessarily present, which makes it possible to reduce the weight of the part and of the assembly incorporating this part. The same applies to part 20 of the figure 2 which may or may not have a bottom.

[0046] Generally, a shim can be inserted into the groove under the bottom of the blade root, in order to facilitate the assembly of the blade with the base and to maintain a constant contact pressure between the blade root and the groove. This shim preferably has a slightly curved shape (banana shape) following its axial extension (along its longitudinal axis) allowing this contact pressure to be exerted once inserted into the groove (due to its elastic deformation). The shim can have a general L shape as illustrated in the figure 5 , to come into contact with the cavity of the base (eg: 20"A) on one side of the groove (on the figure 5 the wedge is curved transversely and not longitudinally as for a "banana" shape but such a curvature also allows assembly by stressing by elastic deformation).

[0047] There figure 6 illustrates, in an axial sectional view along the groove, the shim C1 in position interposed between the blade root 16"A and the groove 18"A of the base 18" fitted into the axial locking part 20". Thanks to this assembly, the shim exerts axial pressure to retain the root axially. In addition, the shim exerts radial pressure from the root on the groove to ensure a matting pressure between these parts. The same arrangement also applies to the shim C2 of the figure 5 The wedge may have a general shape curved along its length in the form of a "banana", a general shape curved like a tile along its transverse direction or a rectilinear L shape, or even a combination of several of these shapes.

[0048] There figure 7 illustrates a wedge shape 40 combining a first part 42 of longitudinal shape curved in the shape of a “banana” and a second part 44 forming a return substantially perpendicular to the first part 42 and which gives the assembly a general L shape. It will be noted that the return 44 has a first face 44a substantially perpendicular to the general direction of longitudinal extension A of the first part 42 and a second opposite face which is convex in order to ensure the axial retention of the root of the blade (a contact pressure between the cavity 20"A on the figure 5 and the 16"A foot of the blade is thus ensured), while allowing assembly.

[0049] The above description of the shims may also apply to the method of making the figures 2 And 3 .

[0050] Although the present invention has been described with reference to specific embodiments, it is obvious that modifications and changes may be made to these examples without departing from the general scope of the invention as defined by the claims. In particular, individual features of the various illustrated / mentioned embodiments may be combined in additional embodiments. Therefore, the description and drawings should be considered in an illustrative rather than restrictive sense.

Claims

1. A turbojet engine fan module wheel (14), having an axial direction (X), a radial direction (R) and a circumferential direction (C), an upstream face (FAM) and a downstream face (FAV), the wheel (14) comprising a plurality of blades (16, 16') made of fiber-reinforced organic-matrix composite material, each blade (16, 16') having a root (16A, 16'A), characterized in that the root is assembled with a base (18, 18') distinct from the bases of the other blades, each base (18, 18') having a groove (18A, 18'A) extending axially and opening out on the side of the upstream face (FAM) and / or on the side of the downstream face (FAV), each root (16A, 16'A) cooperating by axial interlocking in a form-fitting manner, for example in the shape of a dovetail, with the groove (18A, 18'A) of the base (18, 18'), whereby the root (16A, 16'A) is retained on the base (18, 18') along the radial (R) and circumferential (C) directions, and each base (18, 18') cooperates with at least one part (20; 26, 28) configured to axially block the root (16A, 16'A) within the groove (18A, 18'A) of the base (18, 18'), whereby the root (16A, 16'A) is retained along the axial direction (X).

2. The turbojet engine fan module wheel (14) according to claim 1, wherein the blades (16) are variable pitch blades, each of the bases (18) being mounted on a single part (20), distinct from the single parts of the other bases, configured to axially block the root (16A) within the groove (18A) of the base (18), each single part (20) being configured to pivot around the radial direction (R).

3. The turbojet engine fan module wheel (14) according to claim 2, wherein each single part (20) comprises a cavity (20A) receiving at least one piece (18B) of the base (18), the walls of the cavity (20A) clogging the groove (18A) on the side of the upstream face (FAM) and on the side of the downstream face (FAV), whereby the root (16A) is retained along the axial direction (X).

4. The turbojet engine fan module wheel (14) according to claim 2 or 3, wherein each base (18) comprises a flange (18C) extending along the axial (X) and circumferential (C) directions, the base (18) being fixed to the single part (20) via the flange (18C).

5. The turbojet engine fan module wheel (14) according to claim 1, wherein the blades (16') are fixed pitch blades, each base (18') cooperating with an upstream part (26) configured to axially block the root (16'A) within the groove (18'A) of the base (18') towards the side of the upstream face (FAM) and a downstream part (28) configured to axially block the root (16'A) within the groove (18'A) of the base (18') towards the side of the downstream face (FAV).

6. The turbojet engine fan module wheel (14) according to any one of claims 1 to 5, wherein the root (16A, 16'A) of each blade (16, 16') and the groove (18A, 18'A) of each base (18, 18') have the same axial length (L1, L2; L3, L4).

7. The turbojet engine fan module wheel (14) according to any one of claims 1 to 6, wherein the wheel is a turbojet engine fan module outlet rectifier wheel (14).

8. The turbojet engine fan module wheel (14) according to claims 5 and 7, wherein each blade (16') has a tip (16'B) assembled with a second base (24) distinct from the second bases of the others blades, each second base (24) having a groove (24A) extending axially and opening out on the side of the upstream face (FAM) and / or on the side of the downstream face (FAV), each tip (16'B) cooperating by axial interlocking in a form-fitting manner, for example in the shape of a dovetail, with the groove (24A) of the second base (24), whereby the tip (16'B) is retained on the second base (24) along the radial (R) and circumferential (C) directions, and each second base (24) cooperates with at least one second part (30, 32) configured to axially block the tip (16'B) within the groove (24A) of the second base (24), whereby the tip (16'B) is retained along the axial direction (X).

9. The turbojet engine fan module wheel (14) according to claim 8, wherein each second base (24) cooperates with a second upstream part (30) configured to axially block the tip (16'B) within the groove (24A) of the second base (24) towards the side of the upstream face (FAM) and a second downstream part (32) configured to axially block the tip (16'B) within the groove (24A) of the second base (24) towards the side of the downstream face (FAV).

10. The turbojet engine fan module wheel (14) according to claim 8 or 9, wherein the tip (16'B) of each blade (16') and the groove (24A) of each second base (24) have the same axial length (L5, L6).

11. The turbojet engine fan module wheel (14) according to any one of claims 1 to 6, wherein the wheel is a turbojet engine fan wheel (14).

12. A turbojet engine (100) comprising a turbojet engine fan module wheel (14) according to any one of claims 1 to 11.