CN113103626A

CN113103626A - Forming die for fan blade with mixed structure

Info

Publication number: CN113103626A
Application number: CN202010024112.6A
Authority: CN
Inventors: 赵宪涛; 史同承; 曹源; 王少辉; 倪晓琴; 刘传欣
Original assignee: AECC Commercial Aircraft Engine Co Ltd
Current assignee: AECC Commercial Aircraft Engine Co Ltd
Priority date: 2020-01-10
Filing date: 2020-01-10
Publication date: 2021-07-13
Anticipated expiration: 2040-01-10
Also published as: CN113103626B

Abstract

The utility model relates to a mixed structure fan blade forming die, it includes mould and lower mould, is formed with the die cavity between mould and the lower mould, and the die cavity is equipped with the elastomer on the leading edge inner wall in leading edge district including being used for the fashioned blade body district of combined material and being used for placing the metal leading edge, is used for keeping apart the profile contact of metal leading edge and die cavity. The elastic body is arranged on the inner wall of the front edge area of the cavity to isolate the contact of the metal front edge and the molded surface of the cavity, so that scratches or loss of the metal front edge to the inner wall of the cavity are avoided, damage defects such as microcracks and the like of the front edge of the blade are avoided, and the forming process quality of the blade is improved.

Description

Forming die for fan blade with mixed structure

Technical Field

The disclosure relates to the field of aircraft engines, in particular to a forming die for fan blades of a mixed structure.

Background

With the improvement of the fuel economy requirement of modern commercial aircraft engines, the light high-strength composite material is more and more widely applied to the aircraft engines. For components at the cold end of an engine, such as fan blades, fan outlet guide blades, fan containing casings and the like, foreign mature aircraft engine manufacturers have realized that parts or all of the components are made of resin-based composite materials, and the weight reduction effect of the components brings great improvement on fuel efficiency for airlines.

The existing scheme provides a mixed structure fan blade with a metal sandwich, which comprises a metal front edge part and a composite material blade body part, wherein a metal front edge panel and the composite material part are combined into a whole in an interface connection mode, so that the shock resistance of the blade can be enhanced, and the lighter blade can be obtained.

For the fan blade with the metal sandwich special mixed structure, because the front edge of the blade is made of metal, if the traditional mold closing molding process is adopted in the resin transfer molding process, the full-scale blade (including the metal front edge) is completely arranged in a closed mold, the metal front edge possibly scratches or damages the wall surface of the inner cavity of the mold due to insufficient processing precision of the metal front edge of the blade or inaccurate positioning of the blade in the mold; meanwhile, because the mold needs to be heated in the curing process of the resin, if the metal front edge is in direct contact with the inner wall surface of the mold, the deformation characteristics are not matched due to different thermal expansion coefficients of the metal front edge and the inner wall surface of the mold, and the damage defects such as microcracks and the like to the mold or the metal front edge of the blade are likely to be caused, so that the quality of the blade is affected.

Disclosure of Invention

The inventor researches and finds that the related art has the problem that the metal front scratches or damages the wall surface of the inner cavity of the mold.

In view of this, the embodiment of the present disclosure provides a hybrid fan blade forming mold, which can improve the quality of the blade forming process.

The present disclosure provides a hybrid fan blade forming die, including: the composite material forming die comprises an upper die and a lower die, wherein a die cavity is formed between the upper die and the lower die, the die cavity comprises a blade body area for forming a composite material and a front edge area for placing a metal front edge, and an elastic body is arranged on the inner wall of the front edge area and used for isolating the metal front edge from the contact surface of the die cavity.

In some embodiments, the wall surface of the leading edge inner wall is recessed a predetermined depth relative to the wall surface of the body inner wall of the body region, and the natural thickness of the elastomer is greater than the predetermined depth.

In some embodiments, the predetermined depth is greater than or equal to 1 cm.

In some embodiments, the elastomer extends along the boundary between the inner wall of the blade body and the inner wall of the leading edge of the blade body region.

In some embodiments, the elastomer is made of a high temperature resistant rubber material.

In some embodiments, the elastomer is bonded to the leading edge inner wall by an adhesive.

In some embodiments, the binder is a silicone gel.

In some embodiments, the leading edge region is an open cavity for partially receiving a metal leading edge, the leading edge inner wall is configured as a double-layer seal groove, and the elastomer seals the double-layer seal groove.

In some embodiments, the blade further comprises a plurality of pressure sensors disposed on the inner wall of the blade body in the blade body region for monitoring the flow trajectory of the resin.

In some embodiments, the pressure sensor is a metal piezo resistive sensor or a ceramic piezo resistive sensor.

In some embodiments, the plane of the probe of the pressure sensor is lower than the wall surface of the inner wall of the blade body area.

Therefore, according to the embodiment of the disclosure, the elastic body is arranged on the inner wall of the front edge area of the cavity to isolate the contact between the metal front edge and the molded surface of the cavity, so that scratches or loss of the metal front edge to the inner wall of the cavity is avoided, damage defects such as microcracks and the like on the front edge of the blade are avoided, and the blade forming process quality is improved.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the disclosure and together with the description, serve to explain the principles of the disclosure.

The present disclosure may be more clearly understood from the following detailed description, taken with reference to the accompanying drawings, in which:

FIG. 1 is a schematic structural view of a hybrid fan blade with a metal core;

FIG. 2 is a schematic overall external structure view of some embodiments of a hybrid fan blade forming die according to the present disclosure;

FIG. 3 is a schematic structural view of a lower die in some embodiments of a hybrid fan blade forming die according to the present disclosure;

FIG. 4 is a cross-sectional schematic view of some embodiments of a hybrid fan blade forming die according to the present disclosure;

FIG. 5 is a schematic cross-sectional view of further embodiments of a hybrid fan blade forming die according to the present disclosure;

FIG. 6 is a schematic structural view of a lower die in some embodiments of a hybrid geometry fan blade forming die according to the present disclosure;

FIG. 7 is a schematic cross-sectional view at the location of a pressure sensor in some embodiments of a hybrid fan blade forming die according to the present disclosure.

Description of the reference numerals

1. A fully composite region; 2. a metal core region; 3. a metal composite material boundary; 4. a tenon; 5. a blade tip; 6. a metal leading edge; 7. an upper die; 8. a lower die; 9. the inner wall of the blade body;

10. a boundary line; 11. a leading edge inner wall; 12. a cavity; 13. a leaf area; 14. a leading edge region; 15, 15', an elastomer; 16. a pressure sensor; 17. a probe; 18. and (4) conducting wires.

Detailed Description

Various exemplary embodiments of the present disclosure will now be described in detail with reference to the accompanying drawings. The description of the exemplary embodiments is merely illustrative and is in no way intended to limit the disclosure, its application, or uses. The present disclosure may be embodied in many different forms and is not limited to the embodiments herein. These embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art. It should be noted that: the relative arrangement of parts and steps, the composition of materials, numerical expressions and numerical values set forth in these embodiments are to be construed as merely illustrative, and not as limitative, unless specifically stated otherwise.

The use of "first," "second," and similar terms in this disclosure is not intended to indicate any order, quantity, or importance, but rather are used to distinguish one element from another. The word "comprising" or "comprises", and the like, means that the element preceding the word covers the element listed after the word, and does not exclude the possibility that other elements are also covered. "upper", "lower", "left", "right", and the like are used merely to indicate relative positional relationships, and when the absolute position of the object being described is changed, the relative positional relationships may also be changed accordingly.

In the present disclosure, when a specific device is described as being located between a first device and a second device, there may or may not be intervening devices between the specific device and the first device or the second device. When a particular device is described as being coupled to other devices, the particular device may be directly coupled to the other devices without intervening devices or may be directly coupled to the other devices with intervening devices.

All terms used in the present disclosure have the same meaning as understood by one of ordinary skill in the art to which the present disclosure belongs, unless otherwise specifically defined. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.

Techniques, methods, and apparatus known to those of ordinary skill in the relevant art may not be discussed in detail, but are intended to be part of the specification where appropriate.

The mixed structure fan blade is made of two materials, namely metal and composite materials, and is characterized in that the front edge of the blade is made of metal, and the blade body (comprising a suction surface and a pressure surface) is made of the composite material in order to improve the impact resistance of the blade. Fig. 1 shows a fan blade with a mixed structure of metal core, which is divided into a metal leading edge 6, a full composite material region 1, a blade tip 5, a metal core region 2 and a tenon 4. The metal part of the front edge extends to the metal core area 2 of the blade body, the thickness of the metal core area continuously changes according to the thickness change of the blade, and the metal core is arranged in the metal core area 2 of the blade body composite material. The blade is integrally formed by adopting a liquid forming process (such as a resin transfer molding mode), and the full-scale blade is formed and manufactured after resin is filled into a mold to flow, the resin is solidified and the blade is demoulded.

If a traditional closed-mold liquid-state forming process is adopted, the full-scale mixed-structure blade needs to be integrally arranged in a mold. When the mold is closed, the metal part of the front edge of the blade and the inner cavity of the mold form hard contact, and the contact form has two possible consequences: firstly, if the blade is not accurately positioned in the mold, the metal front edge of the blade scratches the inner cavity of the mold, and the mold is damaged in severe cases; and gaps exist between the metal front edge of the blade and the inner cavity of the mold, a complete attaching state cannot be formed, and the gaps can form a quick flow channel during glue injection, so that the flowing state of resin in the mold cannot be effectively controlled, and the defects of local dry spots and the like of the blade can be caused to influence the molding quality.

In view of this, the present disclosure provides a hybrid fan blade forming mold for processing the hybrid fan blade with a metal core. Referring to fig. 2-7, in some embodiments, a hybrid fan blade forming die comprises: the composite material forming die comprises an upper die 7 and a lower die 8, wherein a cavity 12 is formed between the upper die 7 and the lower die 8, the cavity 12 comprises a blade area 13 for forming composite materials and a front edge area 14 for placing a metal front edge 6, the blade area and the front edge area are divided by a boundary line 10, and elastic bodies 15 and 15' are arranged on a front edge inner wall 11 of the front edge area 14 and used for isolating the metal front edge 6 from a molded surface contact of the cavity 12.

As shown in fig. 4, the elastic body 15 is arranged on the front edge inner wall 11 of the front edge area 14 of the cavity 12, after the mold is closed, the elastic body 15 in the mold forms close contact and extrusion on the metal front edge 6, and the elastic body 15 isolates the metal front edge 6 from the molded surface contact of the cavity 12, so that scratches or loss of the metal front edge 6 on the inner wall of the cavity 12 are avoided, meanwhile, damage defects such as microcracks and the like caused by the fact that resin flows into the metal front edge area to form a fast flow channel in the mold filling process are avoided, and the quality of the blade forming process is improved.

To ensure that the elastomer 15 forms a close contact and compression of the metal leading edge 6 after the mold is closed, in some embodiments, as shown in fig. 4, the wall surface of the leading edge inner wall 11 is recessed a predetermined depth relative to the wall surface of the blade body inner wall 9 of the blade body region 13, the natural thickness of the elastomer 15 being greater than the predetermined depth. In order to ensure the accommodation space and the compression reliability of the elastic body 15, in some embodiments, the preset depth is greater than or equal to 1 cm.

In some embodiments, as shown in fig. 3 and 4, the elastic body 15 extends along the boundary line 10 between the blade body inner wall 9 and the leading edge inner wall 11 of the blade body region 13, so that the elastic body 15 is arranged throughout the leading edge region 14, and the elastic body 15 and the metal leading edge 6 are ensured to be in close contact and pressed, so that the resin flow boundary range is strictly limited during mold filling, and resin is effectively prevented from flowing into the metal leading edge region during mold filling.

As for the material of the elastic body 15, in some embodiments, the elastic body 15 is made of a high temperature resistant rubber material to satisfy the temperature range for use in the molding resin process. In other embodiments, the elastomer 15 is made of other high temperature resistant elastic materials. The thickness of the material is determined according to the compressible characteristics of different materials, so that the situation that the elastic body is over-pressed to be incapable of clamping the mold during mold clamping or the metal of the front edge of the blade forms a gap with the surface of the cavity due to the fact that the elastic body is too thin is avoided.

The elastomer 15 needs to be reliably disposed on the leading edge inner wall 11, and in some embodiments, the elastomer 15 is bonded to the leading edge inner wall 11 by an adhesive. In some embodiments, the adhesive is silicone, which has good adhesive properties and can reliably adhere the elastic body 15 to the leading edge inner wall 11. In other embodiments, the adhesive is another adhesive body having adhesive properties.

FIG. 5 illustrates further embodiments of the hybrid fan blade forming die of the present disclosure. Unlike the embodiment shown in fig. 4, the leading edge region 14 is an open cavity for partially receiving the metal leading edge 6, so that the metal leading edge 6 is partially disposed inside the forming mold and partially disposed outside the forming mold, and in order to ensure the mold clamping airtightness, the leading edge inner wall 11 is configured as a double-layer sealing groove, and the elastic body 15' seals the double-layer sealing groove.

The flow track of the resin in the mold is monitored in the resin mold filling process, so that the mold filling process can be adjusted and optimized (such as changing the injection pressure and flow rate of the resin, controlling the opening and closing of each injection/glue outlet and the like), and the molding defects of dry spots and the like caused by the fact that the resin flow front envelopes the interference molded body (or the dry fiber cloth) are avoided. In some embodiments, the hybrid fan blade-forming die further comprises a plurality of pressure sensors 16 disposed on the inner blade wall 9 of the blade body region 13 for monitoring the flow trajectory of the resin. The flow trend of the resin in the mold is determined by arranging the pressure sensor 16, the mold filling speed of the resin is controlled, the glue injection process is ensured to be finished in the injection process window of the resin, and the problem that the mold filling of the full-scale blade cannot be finished due to the fact that the viscosity of the resin is increased due to the fact that the resin is solidified is avoided. The embedded pressure sensors 16 are distributed and designed at different positions of the upper die and the lower die of the die, and the time for the resin to reach a preset position is analyzed and determined according to the reading change of a display screen externally connected with each pressure sensor. The pressure sensors 16 can be respectively designed on the inner wall surfaces of the cavities of the upper die 7 and the lower die 8 of the die, the position distribution of the pressure sensors in the die can be designed according to requirements, and a distribution form of the pressure sensors in the inner cavity of the die is shown in fig. 6. In some embodiments, the pressure sensor 16 is a metal piezo-resistive sensor or a ceramic piezo-resistive sensor, and the reliability and stability of monitoring are high.

As shown in fig. 7, the pressure sensor is embedded, and is mounted on the upper die 7 and the lower die 8 of the die according to the type and size requirements of the sensor. In order to prevent damage to the probe 17 of the pressure sensor 16 due to excessive clamping forces of the preform when the mold is clamped, in some embodiments, the plane of the probe 17 is lower than the wall surface of the blade inner wall 9 of the blade region 13. The action mechanism of the pressure sensor is that when the resin is filled and flows to the monitoring position of the probe 17, the pressure of the resin flow front at the position is continuously changed, the probe 17 transmits the pressure change to an external display screen through an internally connected lead 18, and therefore the position of the resin flow front and the pressure change at the position are judged.

Because the probe of the sensor is not coplanar with the wall surface of the inner cavity of the die, after the resin filling and curing demoulding are finished, resin accumulation and protrusion can occur on the surface of the blade at the position of the pressure sensor, so that the surface finish is influenced. Therefore, the mixed structure fan blade forming die of the embodiment is more suitable for a trial die for forming a composite material part and optimizing process parameters.

Thus, various embodiments of the present disclosure have been described in detail. Some details that are well known in the art have not been described in order to avoid obscuring the concepts of the present disclosure. It will be fully apparent to those skilled in the art from the foregoing description how to practice the presently disclosed embodiments.

Although some specific embodiments of the present disclosure have been described in detail by way of example, it should be understood by those skilled in the art that the foregoing examples are for purposes of illustration only and are not intended to limit the scope of the present disclosure. It will be understood by those skilled in the art that various changes may be made in the above embodiments or equivalents may be substituted for elements thereof without departing from the scope and spirit of the present disclosure. The scope of the present disclosure is defined by the appended claims.

Claims

1. A hybrid fan blade forming die, comprising: go up mould (7) and lower mould (8), go up mould (7) with be formed with die cavity (12) between lower mould (8), die cavity (12) are including being used for fashioned blade district (13) of combined material and leading edge district (14) that are used for placing metal leading edge (6), be equipped with elastomer (15, 15') on leading edge inner wall (11) of leading edge district (14), be used for keeping apart metal leading edge (6) with the profile contact of die cavity (12).

2. The hybrid fan blade forming die of claim 1, wherein the wall surface of the leading edge inner wall (11) is recessed by a predetermined depth with respect to the wall surface of the blade body inner wall (9) of the blade body region (13), and the natural thickness of the elastomer (15, 15') is greater than the predetermined depth.

3. The hybrid fan blade-forming mold of claim 2, wherein the predetermined depth is 1cm or greater.

4. The hybrid fan blade forming die according to claim 1, wherein the elastomer (15, 15') extends along an intersection line (10) of the blade body inner wall (9) of the blade body region (13) and the leading edge inner wall (11).

5. Hybrid fan blade forming die according to claim 1, characterized in that the elastomer (15, 15') is made of a high temperature resistant rubber material.

6. The hybrid fan blade forming die of claim 1, wherein the elastomer (15, 15') is bonded to the leading edge inner wall (11) by an adhesive.

7. The hybrid fan blade forming die of claim 6, wherein the adhesive is silicone.

8. The hybrid fan blade forming die of claim 1, wherein the leading edge region (14) is an open cavity for partially receiving the metal leading edge (6), the leading edge inner wall (11) being configured as a double layer seal groove, the elastomer (15') sealing the double layer seal groove.

9. The hybrid fan blade-forming die of claim 1, further comprising a plurality of pressure sensors (16) disposed on the inner blade wall (9) of the blade body region (13) for monitoring a flow trajectory of resin.

10. The hybrid fan blade forming die of claim 9, wherein the pressure sensor (16) is a metal piezoresistive sensor or a ceramic piezoresistive sensor.

11. The hybrid fan blade forming die of claim 9, wherein a plane of a probe (17) of the pressure sensor (16) is lower than a wall surface of a blade body inner wall (9) of the blade body region (13).