CN112081636B

CN112081636B - Inclusive fan casing

Info

Publication number: CN112081636B
Application number: CN201910505342.1A
Authority: CN
Inventors: 刘鹏; 杨平; 陈美宁; 闫转运; 杨俊�; 曾瑞慧; 徐浩亮
Original assignee: AECC Commercial Aircraft Engine Co Ltd
Current assignee: AECC Commercial Aircraft Engine Co Ltd
Priority date: 2019-06-12
Filing date: 2019-06-12
Publication date: 2022-04-19
Anticipated expiration: 2039-06-12
Also published as: CN112081636A

Abstract

One object of the present invention is to provide a contained fan case that can contain broken or fallen fragments when a blade flying event occurs, preventing the fragments from breaking through the case. The contained fan case for achieving the foregoing objective includes an outer case, an inner case, and a sandwich portion disposed between the outer case and the inner case. The sandwich part comprises a plurality of outer layer armored pieces arranged on the inner peripheral wall surface of the outer layer casing and a plurality of inner layer armored pieces arranged on the outer peripheral wall surface of the inner layer casing. For any adjacent inner-layer armor piece and outer-layer armor piece, the outer-layer armor piece is provided with an outer adjacent edge, the inner-layer armor piece is provided with an inner adjacent edge, an inert explosive thin layer is clamped between the outer adjacent edge and the inner adjacent edge, in the cross section of the casing, the outer adjacent edge, the inner adjacent edge and the inert explosive thin layer extend between the outer casing and the inner casing, an inclination angle is formed in the radial direction relative to the casing, the outer adjacent edge is located on the radial outer side of the inert explosive thin layer, and the inner adjacent edge is located on the radial inner side of the inert explosive thin layer.

Description

Inclusive fan casing

Technical Field

The invention relates to a contained fan casing.

Background

In the high-speed operation process of a turbofan engine, a flying-off event that fan blades are broken and fall off can be caused due to foreign object damage (such as bird collision) or high-low cycle fatigue, and if high-speed and high-energy blade fragments penetrate through a casing and fly out, a cabin, an oil tank, a hydraulic pipeline, an electric appliance control circuit and the like of an airplane can be damaged, so that secondary damage such as cabin decompression, oil tank leakage and fire, airplane control failure and the like can be caused, and the flight safety is seriously threatened. The casing must therefore have sufficient strength to contain any broken or detached blade at the highest operating speed, without major breakage and severe distortion of the casing. The nature of the casing to contain a broken or missing blade is also referred to as the containment of the casing. Data show that 315 times of aviation engine uncontaining accidents occur in 1976-1983, and all aviation countries attach great importance to the engine containment problem.

The existing aeroengine companies at home and abroad have two basic cartridge receiver containment designs, one is the traditional hard wall containment, and high-toughness stainless steel materials are usually adopted to absorb the kinetic energy of the broken blade. The other is soft wall containing, and the thin metal casing is wound with fiber with excellent strength and toughness to absorb the kinetic energy of the broken blade.

The invention patent application with the publication number of 'CN 1923615A' describes a composite containing casing, which is provided with a ceramic layer, a metal layer and a fiber layer, because the ceramic material formed by the ceramic layer has higher hardness than the constituent material of the blade, the blade can be effectively penetrated to damage the blade, the continuous penetration capability of the blade is reduced, meanwhile, the metal layer and the fiber layer prevent the crack on the ceramic layer from expanding through the binding effect formed by welding, and the plasticity of the metal material and the fracture of the fiber can absorb the energy of the blade impact during the crack expanding process. The patent application publication "CN 105756726A" describes a containment case in which a grid reinforcement structure is provided on the case to improve containment of the case.

However, the conventional hard-wall casing in the above design has a heavy weight, and the soft-wall casing has a difficult process and a high manufacturing cost.

Disclosure of Invention

One object of the present invention is to provide a contained fan case that can contain broken or fallen fragments when a blade flying event occurs, preventing the fragments from breaking through the case.

To achieve the above object, a contained fan casing includes an outer casing, an inner casing, and a sandwich portion disposed between the outer casing and the inner casing;

the sandwich part comprises a plurality of outer layer armored pieces arranged on the inner peripheral wall surface of the outer layer casing and a plurality of inner layer armored pieces arranged on the outer peripheral wall surface of the inner layer casing;

the outer layer armor piece is provided with an outer adjacent edge, the inner layer armor piece is provided with an inner adjacent edge, an inert explosive thin layer is clamped between the outer adjacent edge and the inner adjacent edge, the outer adjacent edge, the inner adjacent edge and the inert explosive thin layer extend between the outer layer casing and the inner layer casing in the cross section of the casing, an inclination angle is formed in the radial direction of the casing relative to the outer adjacent edge, the outer adjacent edge is located on the radial outer side of the inert explosive thin layer, and the inner adjacent edge is located on the radial inner side of the inert explosive thin layer.

In one or more embodiments, in the cross-section, the outer armor piece is fan-shaped, having two outer straight sides and an outer arcuate side; the inner-layer armor part is triangular and is provided with two inner straight edges and two inner arc edges; the outer arc edge is attached to the inner peripheral side edge of the outer-layer casing, and the inner arc edge is attached to the outer peripheral side edge of the inner-layer casing;

wherein, the outer straight line limit is the outer adjacent limit, the interior straight line limit is the interior adjacent limit.

In one or more embodiments, in the cross-section, the outer straight side extends from an inner peripheral side of the outer casing to an outer peripheral side of the inner casing, and the inner straight side extends from an outer peripheral side of the inner casing to an inner peripheral side of the outer casing.

In one or more embodiments, the included angles between the two outer straight sides and the two inner straight sides are obtuse angles respectively.

In one or more embodiments, the outer armor piece and the outer casing are connected by a fastener.

In one or more embodiments, the outer armor piece and the outer casing are bonded to each other, and the inner armor piece and the inner casing are bonded to each other.

In one or more embodiments, the casing further comprises baffle members disposed on both sides of the sandwich portion in the axial direction of the casing, each baffle member being fixedly connected to the outer casing and the inner casing, respectively, to restrict movement of the sandwich portion in the axial direction.

In one or more embodiments, the outer casing has a greater thickness than the inner casing.

The fan casing has the advantages that the inner layer and the outer layer of armored pieces and the inert explosive thin layer between the inner layer and the outer layer of armored pieces are arranged in the fan casing, so that the inert explosive thin layer can be subjected to micro explosion when a blade flying-off event occurs to prevent the blades from puncturing the fan casing, and the containment of the fan casing is further improved.

Drawings

The above and other features, properties and advantages of the present invention will become more apparent from the following description of the embodiments with reference to the accompanying drawings, in which:

FIG. 1 illustrates a schematic view of a lower cross-section of one embodiment of a containment fan case;

FIG. 2 is an enlarged view of part A of FIG. 1;

fig. 3 shows a schematic cross-sectional view along the direction a-a in fig. 1.

Detailed Description

The following discloses many different embodiments or examples for implementing the subject technology described. Specific examples of components and arrangements are described below to simplify the present disclosure, but these are merely examples and are not intended to limit the scope of the present disclosure. For example, if a first feature is formed over or on a second feature described later in the specification, this may include embodiments in which the first and second features are formed in direct contact, and may also include embodiments in which additional features are formed between the first and second features, such that the first and second features may not be in direct contact. Additionally, reference numerals and/or letters may be repeated among the various examples throughout this disclosure. This repetition is for the purpose of simplicity and clarity and does not in itself dictate a relationship between the various embodiments and/or configurations discussed. Further, when a first element is described as being coupled or coupled to a second element, the description includes embodiments in which the first and second elements are directly coupled or coupled to each other, as well as embodiments in which one or more additional intervening elements are added to indirectly couple or couple the first and second elements to each other.

It should be noted that, where used, the following description of upper, lower, left, right, front, rear, top, bottom, positive, negative, clockwise, and counterclockwise are used for convenience only and do not imply any particular fixed orientation. In fact, they are used to reflect the relative position and/or orientation between the various parts of the object.

Fig. 1 shows a schematic view of a cross section of an embodiment of a female fan casing, comprising an outer casing 2, an inner casing 3 and a sandwich portion 1 arranged between the outer casing 2 and the inner casing 3, wherein a plurality of fan blades 4 are arranged in the inner casing 3. The sandwich portion 1 has a plurality of outer armor members 10 and a plurality of inner armor members 11, the plurality of outer armor members 10 being provided on an inner peripheral wall surface 20 of the outer casing 2, and the plurality of inner armor members 11 being provided on an outer peripheral wall surface 30 of the inner casing 3. It should be noted that fig. 1 only illustrates one cross section of the fan casing by way of example, which may be a cross section at any position in the axial direction of the fan casing, that is, the cross section at any position in the axial direction of the fan casing has the content shown in fig. 1.

Fig. 2 is a partially enlarged view of part a of fig. 1, and fig. 2 shows a pair of inner armor pieces 11a and outer armor pieces 10a arranged adjacently, it should be noted that the inner armor pieces 11a and outer armor pieces 10a shown in fig. 2 are not intended to limit the adjacent armor pieces referring to the partially enlarged region of part a of fig. 1, and may be adjacent armor pieces at any position in fig. 1, that is, the following description of the inner armor pieces 11a and outer armor pieces 10a arranged adjacently in fig. 2 may be regarded as a description of the inner armor pieces 11 and outer armor pieces 10 arranged adjacently at any position in the interlayer 1. Referring to fig. 2, of the inner armor piece 11a and the outer armor piece 10a which are adjacently arranged, the outer armor piece 10a has an outer adjacent side 100a, the inner armor piece 11a has an inner adjacent side 110a, and a thin layer 15 of inert explosive is interposed between the outer adjacent side 100a and the inner adjacent side 110 a.

In the cross-section of the casing shown in fig. 1 and 2, the outer adjacent edge 100a, the inner adjacent edge 110a and the thin layer 15 of inert explosive sandwiched between the outer adjacent edge 100a and the inner adjacent edge 110a extend between the outer casing 2 and the inner casing 3 in a direction of extension c having an inclination x with respect to the radial direction b of the casing. Specifically, the radial direction b of the casing refers to a radial direction along any cross section of the casing, which may correspond to a radial direction of the casing at any position in the extension, and only one radial direction b of the casing is identified by way of example in the drawings, and it is understood that the extension direction c and the radial direction of the casing at any position in the extension have an inclination angle. Wherein the outer adjacent edge 100a is located on a radially outer side 105 of the thin layer of inert explosive 15 and the inner adjacent edge 110a is located on a radially inner side 106 of the thin layer of inert explosive 15, in particular, being located on the radially outer side 105 means that the outer adjacent edge 100a is closer to the outer casing 2 in the radial direction b of the casing with respect to the thin layer of inert explosive 15, and being located on the radially inner side 106 means that the inner adjacent edge 110a is closer to the inner casing 3 in the radial direction b of the casing with respect to the thin layer of inert explosive 15. It should be noted that, the above description is for the inner layer armor piece 11a and the outer layer armor piece 10a which are adjacently arranged as shown in fig. 2, however, as shown in fig. 1, for any adjacent inner layer armor piece 11 and outer layer armor piece 10, the outer adjacent side 100, the inner adjacent side 110, and the thin inert explosive layer 15 sandwiched therebetween extend in different extending directions between the outer casing 2 and the inner casing 3, respectively, and there is an inclination angle between any extending direction and the radial direction b of the casing at the corresponding position.

Specifically, the inert explosive layer 15 refers to an explosive layer in which powder of an inert explosive is laid, and the inert explosive refers to a substance having explosive ability obtained by adding a desensitizing agent to the explosive. The insensitive agent is usually graphite, can cover the surface of explosive particles and fill gaps in the explosive, absorbs heat at hot spots generated by the explosive under the mechanical action by utilizing the large heat capacity and the small heat conductivity coefficient of the insensitive agent, reduces the temperature, prevents the formed hot spots from further spreading, and reduces the friction and stress concentration phenomena among the explosive grains when the covered explosive grains are positioned among the explosive grains by utilizing the properties of better plasticity, lower strength and easy deformation of the insensitive agent, thereby reducing the probability of generating the hot spots and reducing the mechanical sensitivity of the explosive. So that the inert explosive 15 does not explode under normal mechanical impact, but only under high-speed impact. For the inert explosive 15, it has the following explosive properties: the power is less than 480ml of lead column reaming volume (the lead column reaming volume refers to the volume enlarged after the explosive explodes), the brisance is less than 5mm of lead column compression value (the lead column compression value refers to the height of the lead column compressed by the explosive explosion), the impact sensitivity is less than 2%, the friction sensitivity is less than 2%, the explosion speed is less than 700m/s, the explosion temperature is less than 3200K, and the explosion heat is less than 1000 kcal/kg. It can satisfy and take place miniature explosion when receiving the impact load of blade piece like in the fly-off incident, and can not take place the explosion when receiving less load such as rocking, jolt.

When a flying-off event occurs and the fan blades 4 break and fall off, high-speed and high-energy blade fragments fly out along the radial direction b of the casing and impact the inner casing 3, the inner casing 3 displaces, protrudes or breaks along the radial direction b of the casing, so that the inner armor 11 arranged on the outer wall surface 30 of the inner casing 3 at the corresponding position is extruded or impacted, the inner armor 11 displaces along the radial direction b of the casing to the radial outer side 105, the inert explosive thin layer 15 between the adjacent inner armor 11 and outer armor 10 is extruded or impacted and micro-explosion occurs, the explosion automatically generates an impact force along the radial direction b and the radial inner side 106 of the casing at the explosion position of the inert explosive thin layer 15, and under the action of the impact force, the blade fragments are prevented from flying off continuously, and the inclusion of the fan casing is ensured.

Through set up inside and outside armoured piece and the inertia explosive thin layer between inside and outside armoured piece in fan cartridge receiver, can make the inertia explosive thin layer take place miniature explosion in order to prevent that the blade from puncturing fan cartridge receiver when taking place the blade and take off the incident, and then promoted fan cartridge receiver's inclusion.

While one embodiment of the present contained fan case is described above, in other embodiments of the present contained fan case, the contained fan case may have more details in many respects than the embodiments described above, and at least some of these details may vary widely. At least some of these details and variations are described below in several embodiments.

With continued reference to fig. 1-2, in a cross-section of the fan case, the outer armor member 10 is fan-shaped, having two outer straight edges 102 and two outer curved edges 103; the inner armor 11 is triangular-like and has two inner straight sides 112 and an inner arc side 113; the outer arc 103 is attached to the inner circumferential side of the outer casing 2, and the inner arc 103 is attached to the outer circumferential side of the inner casing 3. it should be noted that the inner circumferential side of the outer casing 2 is a circle represented by the inner circumferential wall surface 20 of the outer casing 2 in the cross section shown in fig. 1 to 2, and the outer circumferential side of the inner casing 3 is a circle represented by the outer circumferential wall surface 30 of the inner casing 3 in the cross section shown in fig. 1 to 2. The outer straight edge 102 is an outer adjacent edge 100a, and the inner straight edge 112 is an inner adjacent edge 110 a. In some embodiments different from those shown in the drawings, in a cross section of the fan casing, the outer layer armored piece 10 and the inner layer armored piece 11 may also be in a trapezoid-like shape, and two oblique sides of the trapezoid are an outer adjacent side and an inner adjacent side.

In one embodiment of the fan case, in a cross section of the fan case, the outer straight line edge 102 extends from the inner peripheral side edge of the outer case 2 to the outer peripheral side edge of the inner case 3 and has

intersection points

102a, 102b with the inner peripheral side edge of the outer case 2 and the outer peripheral side edge of the inner case 3, respectively, the inner straight line edge 112 extends from the outer peripheral side edge of the inner case 3 to the inner peripheral side edge of the outer case 2 and has

intersection points

112a, 112b with the inner peripheral side edge of the outer case 2 and the outer peripheral side edge of the inner case 3, respectively, and the explosive sheet 15 is confined in a space surrounded by the plane of the outer straight line edge 102, the plane of the inner straight line edge 112, the inner peripheral wall surface 20, and the outer peripheral wall surface 30, and is disposed such that the explosive sheet 15 is partitioned between the inner peripheral wall surface 20 and the outer peripheral wall surface 30 by the plurality of outer armor pieces 10 and the plurality of inner armor pieces 11, preventing the occurrence of blade flying apart, the plurality of thin layers 15 of inert explosive cause sympathetic explosions due to conduction of heat between each other. In some embodiments different from those shown, the plurality of thin layers 15 of inert explosive may also be spaced apart by providing a spacer between them.

In one embodiment of the fan case, the included angle y between the two outer straight sides 102 and the included angle z between the two inner straight sides 112 are obtuse angles, respectively.

Fig. 3 shows a schematic cross-sectional view along the direction a-a in fig. 1, where u is the central axis of the casing. The outer armor pieces 10 are fixedly connected with the outer casing 2 through the fasteners 5 so as to prevent the displacement of the plurality of outer armor pieces 10 on the outer casing 2 when the thin layer 15 of the inert explosive is subjected to micro-explosion.

In one embodiment of the fan case, the outer layer armouring 10 and the outer layer case 2 and the inner layer armouring 11 and the inner layer case 3 are bonded respectively, so as to further ensure the firmness of the connection between the outer layer armouring 10 and the outer layer case 2 and between the inner layer armouring 11 and the inner layer case 3, and to prevent the displacement of the outer layer armouring 10 on the outer layer case 2 or the displacement of the inner layer armouring 11 on the inner layer case 3 when the thin layer 15 of inert explosive is exploded.

In one embodiment of the fan casing, the fan casing further comprises baffle members 6, the baffle members 6 being disposed on both sides of the sandwich portion 1 in the axial direction a of the casing, each baffle member 6 being fixedly connected, e.g., welded, to the outer casing 2 and the inner casing 3, respectively, to restrict the movement of the sandwich portion 1 in the axial direction a. Thereby preventing displacement of the sandwich portion 1 when the thin layer 15 of inert explosive explodes.

In one embodiment of the fan case, the outer case 2 has a greater thickness than the inner case 3, and more specifically, the outer case 2 has a greater thickness in the radial direction b than the inner case 3, so as to prevent the outer armor piece 10 from damaging the outer case 2 when the thin layer 15 of inert explosive is exploded.

It should be noted that the cross-sectional views of the fan casing shown in fig. 1 to 2 and the cross-sectional view shown in fig. 3 are not drawn to equal scale, and specifically, the thickness of the sandwich portion 1 in the radial direction b is enlarged to more clearly show the sandwich portion 1 of the fan casing.

Although the present invention has been disclosed in terms of the preferred embodiment, it is not intended to limit the invention, and variations and modifications may be made by one skilled in the art without departing from the spirit and scope of the invention. Therefore, any modification, equivalent change and modification of the above embodiments according to the technical essence of the present invention are within the protection scope defined by the claims of the present invention, unless the technical essence of the present invention departs from the content of the present invention.

Claims

1. A housing case of a inclusive fan comprises an outer layer case, an inner layer case and a sandwich part arranged between the outer layer case and the inner layer case, and is characterized in that,

2. A containment fan case according to claim 1 wherein, in said cross-section, said outer armor piece is fan-shaped having two outer straight edges and an outer arcuate edge; the inner-layer armor part is triangular and is provided with two inner straight edges and two inner arc edges; the outer arc edge is attached to the inner peripheral side edge of the outer-layer casing, and the inner arc edge is attached to the outer peripheral side edge of the inner-layer casing;

3. A containment fan case according to claim 2 wherein, in said cross-section, said outer linear edge extends from an inner peripheral side of said outer case to an outer peripheral side of said inner case, and said inner linear edge extends from an outer peripheral side of said inner case to an inner peripheral side of said outer case.

4. A containment fan case according to claim 2 wherein the included angles between said two outer straight sides and said two inner straight sides are each obtuse angles.

5. A containment fan case according to claim 1 wherein said outer armor piece is connected to said outer case by fasteners.

6. A containment fan case according to claim 1 wherein said outer armor piece is bonded to said outer case and said inner armor piece is bonded to said inner case.

7. A containment fan casing according to claim 1, further comprising baffle members disposed on opposite sides of said sandwich portion in an axial direction of said casing, each of said baffle members being fixedly attached to said outer casing and said inner casing, respectively, to limit movement of said sandwich portion in said axial direction.

8. A containment fan casing as recited in claim 1, wherein said outer casing has a greater thickness than said inner casing.