阅读说明：本技术 复合叶片的成型方法、复合叶片及复合叶片的成型模 (Composite blade forming method, composite blade and composite blade forming die ) 是由 冈部良次 神谷昌美 新藤健太郎 于 2018-09-20 设计创作，主要内容包括：一种复合叶片的成型方法,其固化半固化片而成型出复合叶片(10),复合叶片(10)重叠并接合背侧叶片部件(12)和腹侧叶片部件(14)而成,该复合叶片的成型方法包括：层叠工序(S1),在背侧成型模(32)上形成背侧层叠体(12a),并且在腹侧成型模(34)上形成腹侧层叠体(14a)；内表面隔板配置工序(S2),配置保持由背侧层叠体(12a)及腹侧层叠体(14a)形成的内部空间(20)的内表面隔板(18)；合模工序(S3),对背侧成型模(32)和腹侧成型模(34)进行合模,并且在被内表面隔板(18)保持的内部空间(20)内配置发泡剂(16)；及固化工序(S4),对发泡剂(16)进行加热而使发泡剂(16)膨胀,并且热固化背侧层叠体(12a)及腹侧层叠体(14a)。(A method of forming a composite blade by curing a prepreg to form a composite blade (10), the composite blade (10) being formed by overlapping and joining a back-side blade member (12) and a front-side blade member (14), the method comprising: a laminating step (S1) for forming a back-side laminate (12a) on a back-side molding die (32) and a ventral-side laminate (14a) on a ventral-side molding die (34); an inner surface separator arrangement step (S2) for arranging an inner surface separator (18) that holds an internal space (20) formed by the back-side laminate (12a) and the ventral-side laminate (14 a); a mold clamping step (S3) in which the backside mold (32) and the ventral mold (34) are clamped, and the foaming agent (16) is disposed in the internal space (20) held by the internal surface partition plate (18); and a curing step (S4) in which the foaming agent (16) is heated to expand the foaming agent (16), and the back-side laminate (12a) and the abdominal-side laminate (14a) are heat-cured.)

1. A method of molding a composite blade, which is a composite blade formed of a composite material by curing a reinforcing fiber base material obtained by impregnating a reinforcing fiber with a resin,

the composite blade is formed by overlapping and joining a back side part which is a back side part and a ventral side part which is a ventral side part,

the forming method of the composite blade comprises the following steps:

a laminating step of laminating the reinforcing fiber base material on a back-side molding die for molding the back-side region to form a back-side laminate, and laminating the reinforcing fiber base material on a ventral-side molding die for molding the ventral-side region to form a ventral-side laminate;

a space holding member disposing step of disposing a space holding member that holds an internal space formed by stacking the back-side stacked body and the abdominal-side stacked body;

a mold clamping step of clamping the back-side mold and the abdominal-side mold so as to overlap the back-side laminate and the abdominal-side laminate, and disposing a foaming agent in the internal space held by the space holding member; and

and a curing step of heating the foaming agent to expand the foaming agent, thereby pressurizing the back-side laminate and the abdominal-side laminate from the inside toward the back-side molding die and the abdominal-side molding die, and heating and curing the back-side laminate and the abdominal-side laminate.

2. The method of forming a composite blade according to claim 1,

the space holding member includes a back-side space holding member disposed on the back-side laminated body and a front-side space holding member disposed on the front-side laminated body.

3. The method of forming a composite blade according to claim 2,

in the space holding member arranging step, the back-side space holding member and the front-side space holding member are opposed to each other, and an adhesive is arranged between the back-side space holding member and the front-side space holding member at both end portions of the composite blade of the back-side space holding member and the front-side space holding member in the blade width direction, and both end portions of the back-side space holding member and the front-side space holding member are bonded to each other, thereby forming the space holding member.

4. The method of forming a composite blade according to claim 2 or 3,

the thickness of the back-side space holding member and the ventral-side space holding member is thinner on the central portion side than on the end portion side of the composite blade in the blade width direction.

5. The method of molding a composite blade according to any one of claims 1 to 4,

the space holding member is provided over the entire inner surface of the internal space.

6. The method of molding a composite blade according to any one of claims 1 to 5,

the space holding member uses a resin material or a cured composite material.

7. The method of forming a composite blade according to claim 6,

in the case of using the cured composite material, the space maintainance member includes a reinforcing fiber base material in which the fiber direction of the reinforcing fibers contained in the composite material is oriented at ± 45 ° with respect to the blade length direction of the composite blade.

8. The method of molding a composite blade according to any one of claims 1 to 7,

the space holding member has heat resistance capable of holding the internal space during a period from a temperature at which heating in the curing step is started to a temperature at which the foaming agent expands.

9. The method of molding a composite blade according to any one of claims 1 to 8,

in the space holding member arranging step, both end portions of the space holding member are arranged so as to be positioned closer to the internal space than both end portions of the composite blade in the blade width direction of the composite blade.

10. The method of molding a composite blade according to any one of claims 1 to 9,

in the mold clamping step, the back-side mold is disposed on a lower side in a vertical direction, and the abdominal-side mold is disposed on an upper side in the vertical direction.

11. The method of molding a composite blade according to any one of claims 1 to 10,

the back-side laminate and the ventral-side laminate each have an innermost reinforcing fiber base material provided on the inner space side,

the innermost-layer reinforcing-fiber base material has an area that is the widest of the reinforcing-fiber base materials included in the back-side laminate and the front-side laminate in a plane intersecting the lamination direction of the reinforcing-fiber base materials.

12. The method of forming a composite blade according to claim 11,

in the laminating step, tension is applied to the innermost reinforcing fiber base material in an in-plane direction intersecting the laminating direction of the innermost reinforcing fiber base material.

13. A method of molding a composite blade, which is a composite blade formed of a composite material by curing a reinforcing fiber base material obtained by impregnating a reinforcing fiber with a resin,

the composite blade is formed by overlapping and joining a back side part which is a back side part and a ventral side part which is a ventral side part,

the forming method of the composite blade comprises the following steps:

a laminating step of laminating the reinforcing fiber base material on a back-side molding die for molding the back-side region to form a back-side laminate, and laminating the reinforcing fiber base material on a ventral-side molding die for molding the ventral-side region to form a ventral-side laminate;

a mold clamping step of clamping the back-side mold and the abdominal-side mold so as to overlap the back-side laminate and the abdominal-side laminate, and disposing a foaming agent in an internal space formed by overlapping the back-side laminate and the abdominal-side laminate; and

a curing step of heating the foaming agent to expand the foaming agent, thereby pressurizing the back-side laminate and the abdominal-side laminate from the inside toward the back-side molding die and the abdominal-side molding die and heating and curing the back-side laminate and the abdominal-side laminate,

the back-side laminate and the ventral-side laminate each have an innermost reinforcing fiber base material provided on the inner space side,

an area of the innermost-layer reinforcing-fiber base material in a plane intersecting a stacking direction of the reinforcing-fiber base materials is the widest area of the reinforcing-fiber base materials contained in the back-side laminate and the front-side laminate,

in the laminating step, tension is applied to the innermost reinforcing fiber base material in an in-plane direction intersecting the laminating direction of the innermost reinforcing fiber base material.

14. A composite blade molded by curing a reinforcing fiber base material in which a resin is impregnated into reinforcing fibers and made of a composite material, the composite blade comprising:

a back-side part which is a part on the back side;

a ventral portion which is a ventral side and is overlapped and joined to the dorsal portion;

a space holding member that holds an internal space formed by overlapping the back region and the abdomen region; and

a foaming agent provided inside the space holding member,

in the blade width direction, both end portions of the space holding member are positioned closer to the internal space than both end portions of the back-side portion and the abdomen-side portion.

15. The composite blade of claim 14,

the space holding member includes:

a back-side space holding member disposed at the back-side portion;

a ventral space holding member disposed at the ventral site, facing the dorsal space holding member; and

and an adhesive provided at both ends of the back-side space holding member and the front-side space holding member in the blade width direction and provided between the back-side space holding member and the front-side space holding member.

16. The composite blade according to claim 14 or 15,

the back part and the abdomen part are provided with innermost layer reinforced fiber base materials arranged on the inner space side,

the innermost-layer reinforcing-fiber base material has an area that is the widest of the reinforcing-fiber base materials included in the back-side portion and the stomach-side portion in a plane intersecting the stacking direction of the reinforcing-fiber base materials.

17. A composite blade molded by curing a reinforcing fiber base material in which a resin is impregnated into reinforcing fibers and made of a composite material, the composite blade comprising:

a back-side part which is a part on the back side;

a ventral portion which is a ventral side and is overlapped and joined to the dorsal portion;

a foaming agent provided in an internal space formed by overlapping the back region and the abdomen region,

the back part and the abdomen part are provided with innermost layer reinforced fiber base materials arranged on the inner space side,

the innermost-layer reinforcing-fiber base material has an area that is the widest of the reinforcing-fiber base materials included in the back-side portion and the stomach-side portion in a plane intersecting the stacking direction of the reinforcing-fiber base materials.

18. A composite blade molding die for molding a composite blade made of a composite material by curing a reinforcing fiber base material obtained by impregnating a reinforcing fiber with a resin, characterized in that,

the composite blade is formed by overlapping and joining a back side part which is a back side part and a ventral side part which is a ventral side part,

the composite blade molding die comprises:

a back-side forming die for forming a back-side laminate before forming by laminating the reinforcing fiber base materials; and

a ventral-side forming die for laminating the reinforcing fiber base materials to form a ventral-side laminated body which is the ventral-side part before forming,

the back-side laminate and the ventral-side laminate each have an innermost-layer reinforcing fiber base material provided on an internal space formed by stacking the back-side laminate and the ventral-side laminate,

an area of the innermost-layer reinforcing-fiber base material in a plane intersecting a stacking direction of the reinforcing-fiber base materials is the widest area of the reinforcing-fiber base materials included in the back-side portion and the stomach-side portion,

the back-side molding die and the ventral-side molding die include:

a forming die main body for laminating the reinforcing fiber base material; and

and a tension applying mechanism that applies tension to the innermost reinforcing fiber base material in an in-plane direction intersecting the stacking direction of the innermost reinforcing fiber base material.

Technical Field

The invention relates to a composite blade forming method, a composite blade and a composite blade forming die.

Background

Conventionally, as a composite blade, a gas turbine blade having an airfoil portion extending from a blade tip to a blade root is known (for example, refer to patent document 1). The airfoil portion has a metal portion formed with a surface depression and a foam portion provided to the metal portion with the surface depression, the metal portion and the foam portion being surrounded by and joined to the composite material skin. And the airfoil portion is provided with a corrosion resistant coating covering the composite material skin.

Prior art documents

Patent document

Patent document 1: japanese laid-open patent publication No. H09-303104

Disclosure of Invention

Technical problem to be solved by the invention

As a composite blade, there is a composite blade including no metal portion, and there is a composite blade in which a foaming agent is provided inside a blade body formed by laminating reinforcing fiber base materials. In order to mold a composite blade with high dimensional accuracy while suppressing formation of voids generated in the blade body, the foaming agent is pressurized from the inner side of the composite blade toward a mold for molding the composite blade when thermosetting.

However, in the composite blade, fiber undulation may occur in the composite blade due to the flow of the reinforcing fiber base material of the laminated blade body before the expansion of the foaming agent. Further, when the foaming agent expands, the foaming agent may not be appropriately filled in the blade body, and the thickness of the foaming agent may be reduced. As described above, if the fiber undulation occurs or the thickness of the foaming agent becomes thin, the flexural rigidity of the composite blade decreases, and the natural frequency of the composite blade decreases. If the natural frequency of the composite blade is lowered, the blade thickness of the composite blade needs to be increased to satisfy the required bending rigidity, which causes a problem of lowering the aerodynamic performance. Further, when the undulation of the fiber and the thickness of the foaming agent are individually different, there is a problem that the variation in the natural frequency of the composite blade increases and it becomes difficult to design a detuning so as to avoid the resonance point.

Accordingly, an object of the present invention is to provide a composite blade molding method, a composite blade, and a composite blade mold, which can mold a high-quality composite blade satisfying required performance while achieving weight reduction.

Means for solving the technical problem

A method of molding a composite blade according to the present invention is a method of molding a composite blade made of a composite material by curing a reinforcing fiber base material in which a resin is impregnated into reinforcing fibers, the composite blade being characterized in that the composite blade is formed by overlapping and joining a back portion that is a back portion and a ventral portion that is a ventral portion, the back portion being a back portion, and the ventral portion being a ventral portion, the method comprising: a laminating step of laminating the reinforcing fiber base material on a back-side molding die for molding the back-side region to form a back-side laminate, and laminating the reinforcing fiber base material on a ventral-side molding die for molding the ventral-side region to form a ventral-side laminate; a space holding member disposing step of disposing a space holding member that holds an internal space formed by stacking the back-side stacked body and the abdominal-side stacked body; a mold clamping step of clamping the back-side mold and the abdominal-side mold so as to overlap the back-side laminate and the abdominal-side laminate, and disposing a foaming agent in the internal space held by the space holding member; and a curing step of heating the foaming agent to expand the foaming agent, thereby pressurizing the back-side laminate and the abdominal-side laminate from the inside toward the back-side molding die and the abdominal-side molding die, and heating and curing the back-side laminate and the abdominal-side laminate.

According to this configuration, by disposing the space holding member, the back-side laminated body and the abdominal-side laminated body can be thermally cured while the internal space is held, and the foaming agent can be expanded. Therefore, by holding the internal space by the space holding member, the flow of the reinforcing fiber base material of the back-side laminated body and the abdominal-side laminated body can be suppressed when the back-side laminated body and the abdominal-side laminated body are thermally cured, and therefore, the undulation of the fibers generated at the back-side position and the abdominal-side position can be reduced. Further, since the internal space is held by the space holding member, the expanded foaming agent can be appropriately filled in the internal space, and thus the thickness of the foaming agent can be appropriately adjusted. Therefore, the thickness of the cured back-side laminate and the back-side laminate, that is, the thickness of the back-side region and the thickness of the back-side region in the laminating direction can be set to a desired thickness. This makes it possible to set the bending stiffness of the composite blade to the required bending stiffness, and thus also to set the natural frequency of the composite blade to the required natural frequency.

Preferably, the space holding member includes a back-side space holding member disposed in the back-side laminated body and a front-side space holding member disposed in the front-side laminated body.

According to this configuration, the space holding member can be divided into the back-side space holding member and the abdominal-side space holding member, and therefore the foaming agent can be easily disposed in the internal space held by the space holding member.

In the space holding member arranging step, it is preferable that the space holding member is formed by arranging an adhesive between the back-side space holding member and the ventral-side space holding member at both ends of the composite blade of the back-side space holding member and the ventral-side space holding member in the blade width direction, and adhering both ends of the back-side space holding member and the ventral-side space holding member to each other.

According to this configuration, the space holding member can be integrally formed by bonding the both end portions of the back-side space holding member and the front-side space holding member with the adhesive.

Preferably, the back-side space holding member and the ventral-side space holding member are thinner on the central portion side than on the end portions side of the composite blade in the blade width direction.

According to this configuration, since the back-side space holding member and the ventral-side space holding member are made thinner from the end portions in the blade width direction toward the central portion, the rigidity in the blade width direction is kept constant, and thereby the expansion pressure of the foaming agent can be equalized in the internal space.

Preferably, the space holding member is provided along an entire inner surface of the internal space.

According to this structure, the entire inner surface of the internal space can be held by the space holding member. The expanded foaming agent can pressurize the entire inner surface of the internal space formed by the back-side laminated body and the abdominal-side laminated body via the space holding member.

Also, the space maintainance member preferably uses a resin material or a cured composite material.

With this structure, an inexpensive resin material can be used as the space holding member. Also, the same cured composite material as the composite blade can be used as the space-retaining member, and thus the thermosetting heating of the composite blade can be performed without changing a further thermal condition.

In the case of using the cured composite material, the space holding member preferably includes a reinforcing fiber base material in which the fiber direction of the reinforcing fibers contained in the composite material is oriented to ± 45 ° with respect to the blade longitudinal direction of the composite blade.

With this configuration, the space holding member can be given an elastic force. Accordingly, the space holding member is deflected by the expansion pressure of the foaming agent due to the elastic force, and therefore the back-side laminated body and the abdominal-side laminated body can be appropriately pressurized. The reinforcing fibers are not limited to carbon fibers, and high-elasticity resin fibers such as Kevlar (registered trademark) or Vectran (registered trademark), which are resin fibers having higher elasticity than carbon fibers, may be used.

The space holding member preferably has heat resistance capable of holding the internal space during a period from a temperature at which heating in the curing step is started to a temperature at which the foaming agent expands.

With this configuration, the internal space can be appropriately held by the space holding member until the foaming agent expands.

In the space holding member arranging step, it is preferable that both end portions of the space holding member are arranged so as to be located closer to the internal space than both end portions of the composite blade in the blade width direction of the composite blade.

According to this structure, even when the space holding member is provided, the back-side laminated body and the front-side laminated body can be appropriately joined at both end portions in the blade width direction.

In the mold clamping step, it is preferable that the back-side mold is disposed on a lower side in a vertical direction and the abdominal-side mold is disposed on an upper side in the vertical direction.

With this configuration, the back-side laminated body and the stomach-side laminated body are arranged in a curved state protruding downward. Therefore, the hoop stress by its own weight can be applied to the back-side laminated body and the abdomen-side laminated body.

Preferably, the back-side laminate and the front-side laminate each have an innermost reinforcing fiber base material provided on the inner space side, and the area of the innermost reinforcing fiber base material in a plane intersecting the lamination direction of the reinforcing fiber base materials is preferably the widest area among the reinforcing fiber base materials included in the back-side laminate and the front-side laminate.

In this case, in the laminating step, it is preferable that tension be applied to the innermost reinforcing fiber base material in an in-plane direction intersecting the laminating direction of the innermost reinforcing fiber base material.

According to this configuration, by applying tension to the innermost-layer reinforcing-fiber base material, the flow of the reinforcing-fiber base material included in the back-side laminate and the front-side laminate can be suppressed.

Another method of molding a composite blade according to the present invention is a method of molding a composite blade made of a composite material by curing a reinforcing fiber base material in which a resin is impregnated into reinforcing fibers, the composite blade being characterized in that the composite blade is formed by overlapping and joining a back portion that is a back portion and a ventral portion that is a ventral portion, the back portion being a back portion, and the ventral portion being a ventral portion, the method comprising: a laminating step of laminating the reinforcing fiber base material on a back-side molding die for molding the back-side region to form a back-side laminate, and laminating the reinforcing fiber base material on a ventral-side molding die for molding the ventral-side region to form a ventral-side laminate; a mold clamping step of clamping the back-side mold and the abdominal-side mold so as to overlap the back-side laminate and the abdominal-side laminate, and disposing a foaming agent in an internal space formed by overlapping the back-side laminate and the abdominal-side laminate; and a curing step of heating the foaming agent to expand the foaming agent, thereby pressurizing the back-side laminate and the abdominal-side laminate from the inside toward the back-side molding die and the abdominal-side molding die, and the back-side laminate and the front-side laminate are heated and cured, the back-side laminate and the front-side laminate each having an innermost-layer reinforcing-fiber base material provided on the internal space side, an area of the innermost-layer reinforcing-fiber base material in a plane intersecting a stacking direction of the reinforcing-fiber base materials is the widest area of the reinforcing-fiber base materials contained in the back-side laminate and the front-side laminate, in the laminating step, tension is applied to the innermost reinforcing fiber base material in an in-plane direction intersecting the laminating direction of the innermost reinforcing fiber base material.

According to this configuration, by applying tension to the innermost-layer reinforcing-fiber base material, the flow of the reinforcing-fiber base material included in the back-side laminate and the front-side laminate can be suppressed. Therefore, the undulation of the fibers generated in the dorsal and ventral regions can be reduced. This makes it possible to set the bending stiffness of the composite blade to the required bending stiffness, and thus also to set the natural frequency of the composite blade to the required natural frequency.

A composite blade according to the present invention is a composite blade molded by curing a reinforcing fiber base material in which a resin is impregnated into reinforcing fibers, and composed of a composite material, the composite blade including: a back-side part which is a part on the back side; a ventral portion which is a ventral side and is overlapped and joined to the dorsal portion; a space holding member that holds an internal space formed by overlapping the back region and the abdomen region; and a foaming agent provided inside the space holding member, wherein both end portions of the space holding member are positioned closer to the internal space than both end portions of the back-side portion and the abdomen-side portion in the blade width direction.

According to this configuration, by disposing the space holding member, it is possible to reduce the undulation of the fibers generated in the back-side portion and the ventral-side portion, and to appropriately adjust the thickness of the foaming agent, thereby providing a composite blade that satisfies the required performance (bending rigidity, natural frequency). Even when the space holding member is provided, both end portions of the space holding member are positioned on the inner space side, and thus the back-side laminated body (back-side region) and the abdomen-side laminated body (abdomen-side region) can be appropriately joined at both end portions in the blade width direction.

Further, the space holding member preferably includes: a back-side space holding member disposed at the back-side portion; a ventral space holding member disposed at the ventral site, facing the dorsal space holding member; and an adhesive agent provided at both ends of the back-side space holding member and the front-side space holding member in the blade width direction and provided between the back-side space holding member and the front-side space holding member.

According to this configuration, the space holding member can be divided into the back-side space holding member and the abdominal-side space holding member, and therefore the foaming agent can be easily disposed in the internal space held by the space holding member during molding.

Preferably, the back-side portion and the stomach-side portion have innermost reinforcing fiber base materials provided on the inner space side, and the area of the innermost reinforcing fiber base material in a plane intersecting the stacking direction of the reinforcing fiber base materials is the widest area among the reinforcing fiber base materials included in the back-side portion and the stomach-side portion.

According to this configuration, by applying tension to the innermost-layer reinforcing-fiber base material during molding, it is possible to suppress the flow of the reinforcing-fiber base material contained in the back-side laminate before curing, that is, the back-side laminate, and the abdomen-side laminate before curing, that is, the abdomen-side laminate. Therefore, the undulation of the fibers generated in the dorsal and ventral regions can be reduced.

Another composite blade according to the present invention is a composite blade molded by curing a reinforcing fiber base material in which a resin is impregnated into reinforcing fibers, the composite blade comprising: a back-side part which is a part on the back side; a ventral portion which is a ventral side and is overlapped and joined to the dorsal portion; and a foaming agent that is provided in an internal space formed by overlapping the back region and the abdomen region, wherein the back region and the abdomen region have innermost reinforcing fiber base materials provided on the side of the internal space, and the area of the innermost reinforcing fiber base material is the widest area of the reinforcing fiber base materials included in the back region and the abdomen region in a plane intersecting the stacking direction of the reinforcing fiber base materials.

According to this configuration, by applying tension to the innermost-layer reinforcing-fiber base material during molding, it is possible to suppress the flow of the reinforcing-fiber base material contained in the back-side laminate before curing, that is, the back-side laminate, and the abdomen-side laminate before curing, that is, the abdomen-side laminate. Therefore, the undulation of the fibers generated in the dorsal and ventral regions can be reduced.

The composite blade forming mold of the present invention is a composite blade forming mold for forming a composite blade made of a composite material by curing a reinforcing fiber base material obtained by impregnating a reinforcing fiber with a resin, the composite blade forming mold being characterized in that the composite blade is formed by overlapping and joining a back side portion which is a back side portion and a ventral side portion which is a ventral side portion, the composite blade forming mold comprising: a back-side forming die for forming a back-side laminate before forming by laminating the reinforcing fiber base materials; and a ventral-side molding die for laminating the reinforcing fiber base materials to mold a ventral-side laminate which is the ventral-side portion before molding, wherein the dorsal-side laminate and the ventral-side laminate have innermost-layer reinforcing fiber base materials provided on an inner space side formed by laminating the dorsal-side laminate and the ventral-side laminate, and the innermost-layer reinforcing fiber base materials have the widest area among the reinforcing fiber base materials included in the dorsal-side portion and the ventral-side portion in a plane intersecting with a laminating direction of the reinforcing fiber base materials, and the dorsal-side molding die and the ventral-side molding die have: a forming die main body for laminating the reinforcing fiber base material; and a tension applying mechanism that applies tension to the innermost reinforcing fiber base material in an in-plane direction intersecting the stacking direction of the innermost reinforcing fiber base material.

According to this configuration, since tension can be applied to the innermost reinforcing fiber base material by the tension applying mechanism, the flow of the reinforcing fiber base material included in the back-side laminate and the front-side laminate can be suppressed. Therefore, the undulation of the fibers generated in the dorsal and ventral regions can be reduced.

Drawings

Fig. 1 is a plan view schematically showing a composite blade molded by the composite blade molding method according to embodiment 1.

Fig. 2 is a cross-sectional view schematically showing a thick-walled portion of the composite blade according to embodiment 1.

Fig. 3 is a schematic view showing an example of a part of an inner surface bulkhead of the composite blade according to embodiment 1.

Fig. 4 is a schematic view showing an example of a part of an inner surface bulkhead of the composite blade according to embodiment 1.

Fig. 5 is a schematic view showing an example of a part of an inner surface bulkhead of the composite blade according to embodiment 1.

Fig. 6 is an explanatory view of a foaming agent used in the method for molding a composite blade according to embodiment 1.

Fig. 7 is an explanatory diagram of a method of molding a composite blade according to embodiment 1.

Fig. 8 is a schematic view showing an inner surface bulkhead of a composite blade according to embodiment 2.

Fig. 9 is a schematic view showing an inner surface bulkhead of a composite blade according to embodiment 3.

Fig. 10 is an explanatory diagram illustrating a laminated structure of a composite blade according to embodiment 4.

Fig. 11 is a schematic view showing a mold for molding the composite blade according to embodiment 4.

Detailed Description

Hereinafter, embodiments according to the present invention will be described in detail with reference to the drawings. The present invention is not limited to the present embodiment. Moreover, the constituent elements in the following embodiments include constituent elements that can be easily replaced by those skilled in the art, or substantially the same constituent elements. Further, the constituent elements described below can be appropriately combined, and when there are a plurality of embodiments, the respective embodiments can be combined.

[ embodiment 1]

The method of molding the composite blade 10 according to the present embodiment is a method of molding a blade using a composite material made of reinforcing fibers and resin. As the composite blade 10, for example, a rotor blade or a stationary blade used in a gas turbine, a gas turbine engine, or the like can be applied. In the present embodiment, the composite blade 10 is described as being applied to a rotor blade, but the method of molding the composite blade 10 may also be applied to a stationary blade.

Fig. 1 is a plan view schematically showing a composite blade molded by the composite blade molding method according to embodiment 1. Fig. 2 is a sectional view schematically showing a thick-walled portion of the composite blade according to the present embodiment, and is a sectional view a-a of fig. 1. Fig. 3 to 5 are schematic views showing an example of a part of an inner surface bulkhead of the composite blade according to embodiment 1. Fig. 6 is an explanatory diagram of a foaming agent used in the method for molding a composite blade according to embodiment 1. Fig. 7 is an explanatory diagram of a method of molding a composite blade according to embodiment 1.

First, before a method of molding the composite blade 10 is described, the composite blade 10 will be described. As shown in fig. 1, the composite blade 10 is a rotor blade and extends from a blade root side, which becomes a fixed end, toward a blade tip side, which becomes a free end. Here, the direction connecting the root side and the tip side is the blade longitudinal direction, and is the L direction shown in fig. 1. Further, one side of the composite blade 10 in the direction perpendicular to the longitudinal direction of the blade in fig. 1 is the leading edge side, and the other side is the trailing edge side. The direction connecting the leading edge side and the trailing edge side is the blade width direction and is the W direction shown in fig. 1.

As shown in fig. 2, the composite blade 10 is formed by bending in the blade width direction, and the side that protrudes outward from the inside of the composite blade 10 is the back side, and the side that is recessed outward from the inside of the composite blade 10 is the ventral side. Here, the direction connecting the back side and the ventral side is the blade thickness direction, and is the T direction shown in fig. 2.

The thickness of the composite blade 10 in the blade thickness direction is thick on the root side, and the composite blade 10 is formed to become thinner toward the tip side. Therefore, the tip side of the composite blade 10 is a thin-walled portion having a small thickness in the blade thickness direction, and the root side is a thick-walled portion 10b having a large thickness in the blade thickness direction (see fig. 2).

The composite blade 10 is provided in plurality in a circumferential direction at predetermined intervals on the outer periphery of a rotor that rotates about an axis. Also, the fluid passes between the composite blades 10 from the leading edge side toward the trailing edge side.

As shown in fig. 2, the composite blade 10 includes a back-side blade member (back-side portion) 12 serving as a back-side portion, a ventral-side blade member (ventral-side portion) 14 serving as a ventral-side portion, an inner surface partition plate (space holding member) 18 for holding an internal space 20 formed by the back-side blade member 12 and the ventral-side blade member 14, and a foaming agent 16 provided inside the inner surface partition plate 18.

The back-side blade member 12 is formed by laminating a plurality of prepregs as a reinforcing fiber base material in which a resin is impregnated into a reinforcing fiber and thermally curing the prepregs. The back-side blade member 12 is molded by a back-side molding die 32 described later. The back-side blade member 12 is formed in a convex curved shape of the outer surface of the composite blade 10. Also, the back-side blade member 12 is formed in a curved shape in which the inner surface of the composite blade 10 is concave, and is a part of the inner surface constituting the internal space 20.

As in the case of the back-side blade member 12, the front-side blade member 14 is formed by laminating a plurality of prepregs as a reinforcing fiber base material in which a resin is impregnated into a reinforcing fiber and thermally curing the prepregs. The ventral blade member 14 is molded by a ventral mold 34 described later. The ventral blade member 14 is formed in a curved shape in which the outer surface of the composite blade 10 is concave. Also, the ventral blade member 14 is formed in a curved shape in which the inner surface of the composite blade 10 is convex, and is a part of the inner surface constituting the internal space 20.

Both ends of the back-side blade member 12 in the blade width direction and both ends of the front-side blade member 14 in the blade width direction are joined to each other at a neutral plane P which is a plane including the center of the composite blade 10 in the blade thickness direction. Further, the inner surface between both ends in the blade width direction of the back-side blade member 12 and the inner surface between both ends in the blade width direction of the front-side blade member 14 are formed to be distant to the outer surface side with respect to the neutral plane P, and the inner space 20 is formed by these inner surfaces. The interior space 20 is large on the root side of the composite blade 10 and becomes smaller toward the tip side of the composite blade 10.

In the present embodiment, a prepreg is used as the reinforcing fiber base material, but it is sufficient if the reinforcing fiber and the resin are contained. For example, as the reinforcing fiber, glass fiber and aramid fiber may be applied in addition to carbon fiber, and the reinforcing fiber is not limited to these, and plastic fiber or metal fiber may be applied. The resin is preferably a thermosetting resin, but may be a thermoplastic resin. Examples of the thermosetting resin include epoxy resins, polyester resins, and vinyl ester resins. Examples of the thermoplastic resin include polyamide resin, polypropylene resin, ABS (Acrylonitrile Butadiene Styrene) resin, polyether ether ketone (PEEK), polyether ketone (PEKK), and polyphenylene sulfide (PPS). However, the resin impregnated in the reinforcing fiber is not limited to these, and may be another resin.

An interior surface baffle 18 is disposed along an interior surface of the interior space 20. The inner surface separator 18 is formed by applying the same prepreg as the back-side blade member 12 and the front-side blade member 14, for example. The inner surface baffle 18 is a cured composite material when the composite blade 10 is formed. That is, the cured interior surface separator 19 is applied when assembling the composite blade 10. In embodiment 1, the inner-surface separator 18 is formed using a prepreg, but the material used may be any material, and for example, the material may be formed using only resin, or high-elasticity resin fibers such as Kevlar (registered trademark) or Vectran (registered trademark) may be used as the reinforcing fibers.

The inner surface partition 18 is provided so as to cover the entire inner surface of the internal space 20. Both ends of the inner surface bulkhead 18 are located closer to the internal space 20 than both ends of the composite blade 10 in the blade width direction of the composite blade 10. Therefore, at both end portions in the blade width direction of the composite blade 10, both end portions in the blade width direction of the back-side blade member 12 and both end portions in the blade width direction of the front-side blade member 14 are joined, respectively.

The inner surface partition 18 has heat resistance capable of maintaining the internal space 20 when the composite blade 10 is molded. Specifically, when the composite blade 10 is molded, the inner surface partition 18 has heat resistance to maintain rigidity of the internal space 20 between a heating temperature at which heating starts at the time of thermosetting and a foaming temperature at which the foaming agent 16 expands (foams) as described later. For example, the glass transition temperature of the resin contained in the inner surface separator 18 is 80 ℃ or higher, and the curing temperature of the back-side blade member 12 and the belly-side blade member 14 is or higher.

The inner surface partition 18 includes a back-side partition 18a disposed on the back-side blade member 12 and a front-side partition 18b disposed on the front-side blade member 14. The back-side partition plate 18a and the ventral partition plate 18b are bonded to each other via an adhesive 19 at both ends in the blade width direction. The adhesive 19 is an adhesive film 19 sandwiched between the back-side separator 18a and the abdominal-side separator 18b during molding. The adhesive film 19 may be the same as the resin contained in the inner surface separator 18, or may be an adhesive film that adheres at normal temperature, and is not particularly limited.

The back-side separator 18a and the ventral separator 18b are molded by laminating prepregs and curing them. The back-side baffle plate 18a is formed in a curved shape in which the outer surface in contact with the back-side blade member 12 is convex. The rear-side separator 18a is formed in a curved shape in which the inner surface in contact with the foaming agent 16 is recessed. The thickness of the back-side partition plate 18a in the blade thickness direction is constant in the blade length direction and the blade width direction. The back-side separator 18a is made of a prepreg in which the fiber direction of the reinforcing fibers contained in the prepreg is oriented at ± 45 ° with respect to the reference direction when the blade longitudinal direction of the hybrid blade 10 is the reference direction. By including such a prepreg, the back-side separator 18a can be configured to impart elasticity. When the composite blade 10 is molded, the elastic force of the back-side partition 18a is an elastic force that is deflected as it is when internal pressure (expansion pressure) is applied by expansion of the foaming agent 16, and is an elastic force capable of maintaining the internal space 20 before the foaming agent 16 expands.

The ventral partition 18b is formed in a curved shape in which the outer surface in contact with the ventral blade member 14 is concave. The ventral partition 18b is formed in a curved shape in which the inner surface in contact with the foaming agent 16 is convex. The thickness of the ventral partition 18b in the blade thickness direction is constant in the blade length direction and the blade width direction, similarly to the back-side partition 18 a. Similarly to the back-side separator 18a, the ventral separator 18b is made of a prepreg in which the fiber direction of the reinforcing fibers contained in the prepreg is oriented at ± 45 ° with respect to the reference direction when the blade longitudinal direction of the hybrid blade 10 is the reference direction. By including such a prepreg, the ventral separator 18b can also have a structure that gives an elastic force similar to that of the back-side separator 18 a.

Next, the structure of the end portion of the inner surface separator 18 in the blade width direction will be described with reference to fig. 3 to 5. The end portions of the inner surface separator 18 in the blade width direction are formed by joining the end portions of the back-side separator 18a and the ventral separator 18b in the blade width direction via an adhesive 19. That is, the adhesive edges 21 are formed at the ends of the back-side separator 18a and the stomach-side separator 18b in the blade width direction, and the adhesive edges 21 are bonded to each other with the adhesive 19.

As an example of the end portion of the inner surface separator 18 shown in fig. 3, the end portion of the back-side separator 18a in the blade width direction is bent to the outer surface side to form an adhesive edge 21a on the inner surface side, and the end portion of the stomach-side separator 18b in the blade width direction is slightly bent to the inner surface side to form an adhesive edge 21b on the inner surface side. Thereby, the bonding edges 21a, 21b of the back-side separator 18a and the stomach-side separator 18b protrude outward of the inner-side separator 18.

As an example of the end portion of the inner surface separator 18 shown in fig. 4, an end portion in the blade width direction of the back-side separator 18a is bent toward the inner surface side to form an adhesive edge 21a on the outer surface side, and an end portion in the blade width direction of the abdominal-side separator 18b is bent toward the inner surface side to form an adhesive edge 21b on the outer surface side. Thereby, the bonding edges 21a, 21b of the back-side separator 18a and the stomach-side separator 18b protrude inward of the inner-side separator 18.

As an example of the end portion of the inner surface separator 18 shown in fig. 5, an end portion of the back-side separator 18a in the blade width direction is bent toward the inner surface side to form an adhesive edge 21a on the outer surface side, and the inner surface side of the end portion of the ventral separator 18b in the blade width direction is directly used as the adhesive edge 21 b. Thereby, the bonding edge 21a of the back-side separator 18a protrudes inward of the inner-side separator 18 and is provided along the inner surface of the stomach-side separator 18 b.

The foaming agent 16 is filled in the interior of the interior surface partition 18. The foaming agent 16 is disposed inside the inner surface separator 18 before foaming, and then heated to foam, thereby filling the inside of the inner surface separator 18. The foaming agent 16 filled in the inner surface separator 18 is formed as a layer-like foamed layer. As shown in fig. 6, the foaming agent 16 is configured to contain a resin component 25, a foaming component 26, and a fiber component 27. The resin component 25 is cured by heating, and may be the same as the resin contained in the reinforcing fiber base material. The foaming component 26 is foamed by heating, and for example, the foaming component 26 is heated to carbon dioxide or the like, thereby generating bubbles 28 in the resin component 25. The fiber component 27 is added to make the foaming of the foaming component 26 into a uniform and stable foaming form.

The state of the foaming agent 16 shown on the left side of fig. 6 is a state before foaming, and the foaming agent 16 in the state before foaming is heated to generate the bubbles 28, thereby expanding the volume of the foaming agent 16 and curing the resin component 25 after the volume expansion.

Next, a method of molding the composite blade 10 will be described with reference to fig. 7. The method of molding the composite blade 10 of the present embodiment sequentially performs a laminating step S1, an inner surface partition plate disposing step (space holding member disposing step) S2, a mold clamping step S3, a curing step S4, and a mold releasing step S5.

In the laminating step S1, a back-side laminating step S1a of forming the back-side laminate 12a before the back-side blade member 12 is molded and a front-side laminating step S1b of forming the front-side laminate 14a before the front-side blade member 14 is molded are performed.

In the back-side laminating step S1a, prepregs are laminated on the back-side molding die 32 for molding the back-side blade member 12, thereby forming the back-side laminate 12 a. The back-side molding die 32 has a back-side molding surface 32a for molding the outer surface of the back-side blade member 12, and a flat back-side mold bonding surface 32b provided around the back-side molding surface 32 a. In order to mold the outer surface of the back-side blade member 12 into a convex curved shape, the back-side molding surface 32a is formed to be concave. In the back-side laminating step S1a, the back-side molding die 32 is placed so that the back-side molding surface 32a faces upward in the vertical direction. Then, a prepreg is laminated on the back molding surface 32a of the back molding die 32 to form a back laminate 12 a. In the back-side laminating step S1a, the back-side laminate 12a is formed by vacuum evacuation for every several layers of prepregs to be laminated.

In the ventral lamination step S1b, prepregs are laminated on the ventral mold 34 for molding the ventral blade member 14, thereby forming a ventral laminate 14 a. The ventral-side molding die 34 has a ventral-side molding surface 34a for molding the outer surface of the ventral-side blade member 14, and a flat ventral-side mold clamping surface 34b provided around the ventral-side molding surface 34 a. The front molding surface 34a is formed to protrude convexly in order to mold the outer surface of the front blade member 14 into a concavely curved shape. In the ventral-side laminating step S1b, the ventral-side forming die 34 is placed so that the ventral-side forming surface 34a faces upward in the vertical direction. Then, prepregs are laminated on the ventral molding surface 34a of the ventral molding die 34 to form a ventral laminate 14 a. In the ventral lamination step S1b, the ventral laminate 14a is formed by vacuum evacuation for every several layers of prepregs to be laminated, as in the back-side lamination step S1 a.

In the inner surface separator arranging step S2, a back-side separator arranging step S2a of arranging the back-side separator 18a on the back-side laminated body 12a and a stomach-side separator arranging step S2b of arranging the stomach-side separator 18b on the stomach-side laminated body 14a are performed.

In the back-side separator disposing step S2a, the inner surface of the back-side separator 18a is placed so as to face the upper side in the vertical direction, so that the outer surface of the back-side separator 18a is in contact with the back-side laminated body 12 a.

In the abdomen-side separator arrangement step S2b, the inner surface of the abdomen-side separator 18b is placed so as to face the upper side in the vertical direction, and the outer surface of the abdomen-side separator 18b is brought into contact with the abdomen-side stacked body 14 a.

In embodiment 1, the back-side separator 18a and the abdominal-side separator 18b are disposed in a separated state, but the back-side separator 18a and the abdominal-side separator 18b may be bonded together with an adhesive in advance, and the integrated inner surface separator 18 may be disposed on the back-side laminate 12a or the abdominal-side laminate 14 a.

In the mold clamping step S3, the back-side mold 32 and the ventral-side mold 34 are clamped together, and the foaming agent 16 is disposed. Specifically, in the mold clamping step S3, the back-side mold 32 is disposed on the lower side in the vertical direction, and the abdominal-side mold 34 is disposed on the upper side in the vertical direction. In the mold clamping step S3, the back-side laminate 12a laminated on the back-side mold 32 and the front-side laminate 14a laminated on the front-side mold 34 are superimposed on each other at the neutral plane P by superimposing the back-side mold surface 32b of the back-side mold 32 and the front-side mold surface 34b of the front-side mold 34. When the back-side laminate 12a and the abdominal-side laminate 14a are stacked, the adhesive edge 21a of the back-side separator 18a and the adhesive edge 21b of the abdominal-side separator 18b are opposed to each other, and an adhesive film is sandwiched between the adhesive edge 21a and the adhesive edge 21b, thereby forming the inner-surface separator 18. In embodiment 1, the ends of the back-side separator 18a and the ventral separator 18b in the blade width direction are bonded to each other, but if it is necessary to bond the ends of the back-side separator 18a and the ventral separator 18b in the blade length direction to each other, a bonding edge may be formed at the end in the blade length direction and bonded thereto.

In the mold clamping step S3, the back-side laminated body 12a and the stomach-side laminated body 14a, which are stacked, form a hollow internal space 20, and the internal surface partition plate 18 is disposed on the internal surface of the internal space 20.

In the mold clamping step S3, the foaming agent 16 before foaming is provided inside the inner surface separator 18 before the back-side laminated body 12a and the stomach-side laminated body 14a are superposed. The foaming agent 16 before foaming is formed into a sheet shape. In the mold clamping step S3 of embodiment 1, the back-side mold 32 is positioned below the front-side mold 34, and the foaming agent 16 before foaming is provided on the inner surface of the back-side partition plate 18 a.

In the curing step S4, the back-side laminate 12a, the abdominal-side laminate 14a, and the foaming agent 16 are heated while being pressed in the direction in which the back-side mold 32 and the abdominal-side mold 34 are moved closer. In the curing step S4, the foaming component 26 of the foaming agent 16 is foamed by heating while the internal space 20 is held by the internal surface partition 18, before the resin component 25 of the foaming agent 16 and the resin of the prepreg (the back-side laminate 12a and the abdominal-side laminate 14a) are cured. When the foaming component 26 is foamed, the foaming component 26 forms the cells 28, and thereby the resin component 25 before curing expands. Therefore, by the expansion of the foaming agent 16, a pressure (expansion pressure) is applied from the inside of the internal space 20 to the outside through the internal surface partition 18, whereby the back-side laminated body 12a and the abdominal-side laminated body 14a before curing are pressed by the foaming agent 16 toward the back-side molding die 32 and the abdominal-side molding die 34. At this time, the internal space 20 is held by the internal surface partition 18, and the internal space 20 (the inside of the internal surface partition 18) is appropriately filled with the foaming agent 16. After the foaming component 26 of the foaming agent 16 is foamed, the resin of the prepreg is cured first or the resin component 25 of the foaming agent 16 and the resin of the prepreg are cured at the same time, whereby the back-side laminate 12a and the belly-side laminate 14a are thermally cured in a state of being pressurized by the foaming agent 16. After or simultaneously with curing the resin of the prepreg, the resin component 25 of the foaming agent 16 is thermally cured, whereby the foaming agent 16 is integrated with the back-side laminate 12a and the belly-side laminate 14 a. Then, the composite blade 10 is molded by curing the back-side laminated body 12a, the ventral-side laminated body 14a, and the foaming agent 16.

In the mold-releasing step S5, the molded composite blade 10 is released from the back-side mold 32 and the ventral-side mold 34 by moving the back-side mold 32 and the ventral-side mold 34 in the direction away from each other.

As described above, according to embodiment 1, by disposing the inner surface separator 18, the foaming agent 16 can be expanded while the back-side laminated body 12a and the abdominal-side laminated body 14a are thermally cured while the internal space 20 is maintained. Therefore, by holding the internal space 20 by the internal surface partition 18, the flow of the prepreg in the back-side laminate 12a and the front-side laminate 14a can be suppressed when the back-side laminate 12a and the front-side laminate 14a are thermally cured, and therefore, the undulation of the fibers generated in the back-side blade member 12 and the front-side blade member 14 can be reduced. Further, by holding the internal space 20 by the internal surface partition 18, the internal space 20 can be appropriately filled with the expanded foaming agent 16, and therefore the thickness of the foaming agent 16 can be appropriately adjusted. Therefore, the thickness of the cured back-side blade member 12 and the belly-side blade member 14 in the stacking direction can be set to a desired thickness. This makes it possible to set the required flexural rigidity of the composite blade 10 without reducing the flexural rigidity, and therefore the natural frequency of the composite blade 10 can be set to the required natural frequency.

Further, according to embodiment 1, the inner surface separator 18 can be divided into the back-side separator 18a and the stomach-side separator 18b, and therefore the foaming agent 16 can be easily disposed inside the inner surface separator 18.

Further, according to embodiment 1, the entire inner surface of the internal space 20 can be held by the inner surface partition 18. The expanded foaming agent 16 can pressurize the entire inner surface of the internal space 20 formed by the back-side laminated body 12a and the stomach-side laminated body 14a via the inner surface partition 18.

Further, according to embodiment 1, as a material of the inner surface separator 18, a prepreg which is a composite material of the composite blade 10 can be used. Accordingly, the thermosetting heating of the composite blade 10 can be performed without changing the more thermal condition.

Further, according to embodiment 1, the inner surface separator 18 can be given an elastic force. Therefore, the inner surface separator 18 is deflected by the expansion pressure of the foaming agent 16 due to the elastic force, and thus the back-side laminated body 12a and the stomach-side laminated body 14a can be appropriately pressurized.

Further, according to embodiment 1, the inner-surface partition 18 has heat resistance that enables the internal space 20 to be maintained during a period from a heating temperature at which heating starts to a foaming temperature at which the foaming agent 16 expands, and therefore enables the internal space 20 to be appropriately maintained until the foaming agent 16 expands.

Further, according to embodiment 1, the inner surface separator 18 is positioned on the inner side of the composite blade 10 in the blade width direction, and therefore, even when the inner surface separator 18 is provided, the back-side laminated body 12a and the abdominal-side laminated body 14a can be appropriately joined at both end portions in the blade width direction.

Further, according to embodiment 1, since the back-side mold 32 is disposed on the lower side in the vertical direction and the abdominal-side mold 34 is disposed on the upper side in the vertical direction, the back-side laminate 12a and the abdominal-side laminate 14a are disposed in a curved state protruding downward. Therefore, the hoop stress by its own weight can be applied to the back-side laminated body 12a and the stomach-side laminated body 14 a.

In embodiment 1, the thickness of the back-side diaphragm 18a and the ventral diaphragm 18b in the blade thickness direction is constant in the blade longitudinal direction and in the blade width direction, but the present invention is not limited to this configuration. The back-side diaphragm 18a and the ventral diaphragm 18b may have a smaller thickness at the center portion than at the end portions in the blade width direction. According to this configuration, since the back-side partition plate 18a and the stomach-side partition plate 18b are made thinner from the end portions in the blade width direction toward the central portion, the rigidity in the blade width direction is kept constant, and thereby the expansion pressure of the foaming agent 16 can be equalized in the internal space 20.

[ embodiment 2]

Next, a composite blade 10 according to embodiment 2 will be described with reference to fig. 8. In embodiment 2, in order to avoid redundant description, portions different from embodiment 1 will be described, and portions having the same configuration as embodiment 1 will be described with the same reference numerals. Fig. 8 is a schematic view showing an inner surface bulkhead of a composite blade according to embodiment 2.