JP2009269349A - Molding core, and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a molding core that can maintain pressure resistance and dimensional stability. <P>SOLUTION: The molding core 10 is formed in elongate shape. The molding core 10 comprises a core body 11 formed of a viscoelastic material, and a cylindrical fiber reinforced material 13 embedded in the core body 11 along its length direction. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a molding core formed in an elongated shape and a method for manufacturing the same.

As structural members for aircraft, ships, automobiles, etc., those made of fiber reinforced plastics (FRP) are widely used from the viewpoint of weight reduction. As a method for producing such a structural member, for example, as disclosed in Patent Documents 1 and 2, a fiber laminate in which a reinforcing fiber substrate is laminated in advance is shaped into a final product shape to form a preform. An RTM method (Resin Transfer Molding method) in which a matrix resin is injected and cured into a reform, or a layer in which multiple layers of fibers and resin are laminated alternately is placed in an autoclave, and a predetermined heat is applied under a predetermined pressure. And an autoclave method for curing the resin.
JP 2007-62150 A JP 2007-118598 A

  By the way, in the case of forming a reinforcing hollow rib on the structural member, a rubber molding core formed in an elongated shape is provided in advance when setting the material to the mold before molding, and molding is performed after molding. For example, the molding core is pulled out from the product.

  However, since the molding core is repeatedly used for the production of the structural member, it is difficult to maintain the pressure resistance against the pressurization during the production of the structural member because it is formed of only rubber. In addition, there is a problem that it is difficult to maintain dimensional stability due to shrinkage caused by heating and cooling during the manufacture of the structural member.

  The objective of this invention is providing the core for shaping | molding which can maintain pressure resistance and dimensional stability, and its manufacturing method.

The present invention is a molding core formed in an elongated shape,
A core body formed of a viscoelastic material;
A cylindrical fiber reinforcement embedded in the core body along its length direction;
It is provided with.

The present invention includes a core body that is formed in an elongated shape and made of a material having viscoelasticity, and a cylindrical fiber reinforcing material that is embedded in the core body along the length direction thereof. A method for producing a molding core, comprising:
The core material is covered with a cylindrical fiber reinforcing material, embedded in a material for forming the core body, and heated and pressurized.

  According to the molding core of the present invention, since the cylindrical fiber reinforcing material is embedded and reinforced along the length direction of the core body, the pressure resistance and the dimensional stability are maintained even if it is repeatedly used. Can be maintained.

  Hereinafter, embodiments will be described in detail based on the drawings.

  FIG. 1 shows a molding core 10 according to the present embodiment. The molding core 10 according to the present embodiment is provided in advance in a mold at the time of material setting before molding when manufacturing FRP components such as aircraft, ships, automobiles, etc. by a method such as RTM method or autoclave method. It is used to form a hollow part in the constituent member by being pulled out from the constituent member which is a molded product after molding.

  The molding core 10 is formed in an elongated shape having a rectangular cross section. The molding core 10 is formed with a hollow portion having a rectangular outer cross-sectional shape extending in the length direction at the center thereof. The molding core 10 may be formed in a straight line shape or may be formed in a bow shape. The molding core 10 has, for example, a length of 0.5 to 15 m, a width of 50 to 150 mm, a height of 20 to 150 mm, and a vertical diameter of the hollow portion H of 10 to 50 mm and a horizontal diameter of 20 mm. ˜100 mm and the wall thickness is generally 2 to 30 mm.

  The molding core 10 has a core body 11 constituting the outer shape formed of a material having viscoelasticity, and a surface made of a sheet-like fluorine film so as to cover and cover the surface of the core body 11 The covering film 12 is provided integrally with the core main body 11, and the fiber reinforcing material 13 is embedded in the core main body 11 so as to surround the hollow portion.

  According to the molding core 10, the cylindrical fiber reinforcing material 13 is embedded and reinforced along the length direction of the core body 11, so that pressure resistance and dimensional stability are maintained even when used repeatedly. Can be maintained.

  In addition, when the length of the molding core is long, it is difficult to pull out the molding core from the constituent member that is a molded product. However, according to the molding core 10, the molding core 10 is integrally formed with the core body 11. Further, since the surface covering film 12 of the fluorine film is provided so as to cover the surface of the core body 11, the slip resistance of the surface is low, so that it can be easily pulled out from the constituent member which is a molded product.

  Examples of the viscoelastic material forming the core body 11 include a crosslinked polymer composition such as a rubber material or a resin material. The polymer composition is obtained by crosslinking an uncrosslinked polymer composition in which a raw material polymer is blended with a curing agent, a pigment, or the like, by heating and pressing. The molding core 10 has a durometer type A spring-type surface hardness measured according to JIS K6253, for example, 50 to 80, and the uncrosslinked polymer composition is blended and designed so that such surface hardness is realized. ing.

  The polymer composition is preferably a silicone rubber composition from the viewpoint of heat resistance. In this case, examples of the raw material polymer include polydimethyl silicone rubber (MQ), methyl vinyl silicone rubber (VMQ), methyl phenyl silicone rubber (PMQ), and fluorosilicone rubber (FVMQ). Examples of the curing agent include organic peroxides such as alkyl organic peroxides. In addition, the silicone rubber composition may contain a reinforcing agent (silica), a pigment, an internal mold release agent, and the like.

  Examples of the fluorine film constituting the surface coating film 12 include those formed of polytetrafluoroethylene (PTFE), those formed of tetrafluoroethylene / ethylene copolymer (ETFE), and tetrafluoroethylene / perfluoro. Those formed with an alkyl vinyl ether copolymer (PFA) and those formed with a tetrafluoroethylene / hexafluoropropylene copolymer (FEP) are mentioned, and among these, formed with polytetrafluoroethylene (PTFE) Those are preferred.

  The surface covering film 12 is formed in a sheet shape and is provided so as to wrap the core body 11. The presence of wrinkles on the surface of the molding core 10 means that the wrinkles are transferred to the component that is the molded product, and resistance when the molding core 10 is pulled out from the component that is the molded product. This is not preferable. However, since the surface coating film 12 is formed in a sheet shape and is provided so as to wrap the core body 11, the surplus portion of the surface coating film 12 is at the end when the molding core 10 is manufactured. Thus, generation of wrinkles of the surface coating film 12 on the surface of the molding core 10 is suppressed.

  The surface covering film 12 has a thickness of, for example, 50 to 200 μm.

  Moreover, the surface coating film 12 is provided so that it may face | match at the top part of the corner | angular part 11a of the core main body 11. FIG. Thereby, the butted portion where the surface coating film 12 becomes discontinuous is not arranged on the flat portion of the component member which is a molded product, and the transfer thereof is prevented. At the time of manufacturing the molding core 10, the core body The surplus portion of the material forming 11 flows out from the butted portion of the surface coating film 12, thereby forming the core body 11 with less internal distortion.

  The surface covering film 12 is not limited to this, and may be a cylindrical one provided so as to cover the core body 11, and may be spirally wound around the core body 11. It may be a belt-like one provided in the.

  The fiber reinforcing material 13 is formed in a cylindrical shape, and is embedded in the inner layer of the core body 11 so as to be exposed from the hollow portion and to include the hollow portion.

  Examples of the fiber material constituting the fiber reinforcement 13 include aramid fiber, nylon fiber, polyester fiber, glass fiber, and carbon fiber. The fiber material that constitutes the fiber reinforcement 13 may be composed of a single species or a plurality of species.

  The fiber reinforcing material 13 may be composed of a braid, may be composed of a woven fabric, may be further composed of a knitted fabric, and may be composed of a non-woven fabric. The fiber reinforcing material 13 has a thickness of, for example, 0.1 to 1.0 μm.

  Examples of the braid include, for example, a flat strut braid; a round strut braid; a vertical stripe braid, a cross-jointed braid, a double braid, and a braid lace rugged hammer strut.

  The yarn constituting the braided fiber reinforcing material 13 is not particularly limited, and may be a yarn composed of only one kind of fiber material, or a mixture of plural kinds of fiber materials. The thread may be a The yarn has a thickness of, for example, 200 to 1500 dtex, and a yarn crossing angle of 10 to 90 °. The diameter of the single yarn fiber constituting the yarn is, for example, 5 to 50 μm.

  The braided fiber reinforcement 13 may be provided on the core body so that the yarn extending in two directions extends in any direction, for example, one of them extends in the length direction of the core body. Or one of them may be provided so as to extend in the width direction of the core body, and any one of them may be provided in the length direction or width direction of the core body. It may be provided with an inclination.

  As the woven fabric, for example, a woven fabric having a basic structure such as plain weave, oblique woven fabric, or satin weaving; Woven double woven fabrics, warp double woven fabrics, double woven fabrics and other laminated fabrics; twisted fabrics; weft pile fabrics, warp pile woven fabrics; .

  The warp and weft constituting the woven fiber reinforcing material 13 are not particularly limited, and may be a yarn composed of only one kind of fiber material, or a mixture of plural kinds of fiber materials. It may be a constructed yarn. The warp and weft have a thickness of, for example, 300 to 1500 dtex, and the crossing angle is generally 90 °. The diameter of the single yarn fiber constituting the warp and the weft is, for example, 10 to 300 μm.

  The fiber reinforcing material 13 of the woven fabric may be provided on the core body so that the warp and the weft extend in any direction. For example, one of them extends in the length direction of the core body. May be provided, or one of them may be provided so as to extend in the width direction of the core body, and any one of them may be provided with respect to the length direction or the width direction of the core body. It may be provided with an inclination.

  As the knitted fabric, knitted fabrics with basic structures such as flat knitting, rubber knitting, double-sided knitting, pearl knitting, etc .; Jacquard edition, Blister edition (change organization common to all basic organizations), Kanoko edition, back hair edition, semi-transfer edition, sinker fish net, accordion edition, boss neck pattern, spiral mesh (above, flat knitting type) (Change organization), teleco knitting, one-sided knitting, two-sided knitting, swing knitting, rope knitting, stitch knitting, milan rib, double picke (more than rubber knitting type knitting structure), mock milan rib, eight lock, three-step double ed Examples thereof include knitted fabrics having a changed structure such as picket (above, double-sided knitted pattern changing structure).

  The yarn constituting the fiber reinforcing material 13 of the knitted fabric is not particularly limited, and may be a yarn constituted by only a single type of fiber material, or a mixture of a plurality of types of fiber materials. It may be a warp thread. The yarn has a thickness of, for example, 100 to 1500 dtex. The diameter of the single yarn fiber constituting the yarn is, for example, 5 to 100 μm.

  The braided fiber reinforcement 13 may be provided on the core body so that the wale and the course extend in any direction. For example, one of them extends in the length direction of the core body. May be provided, or one of them may be provided so as to extend in the width direction of the core body, and any one of them may be provided with respect to the length direction or the width direction of the core body. It may be provided with an inclination.

  The fiber reinforcing material 13 may be formed in a cylindrical shape by joining ends thereof, or may be formed in a seamless cylindrical shape. Examples of the fiber reinforcing material 13 formed in a seamless cylindrical shape include a bag-woven fabric, a braid, and a circular knitted fabric.

  Next, the manufacturing method of the molding core 10 according to the present embodiment will be described with reference to FIGS. 2 (a) to 2 (c) and FIGS. 3 (a) to 3 (c).

  The core molding die 20 includes a lower mold 21 and an upper mold 22, and the lower mold 21 is provided with a lower concave groove 23 that constitutes a cavity and a guide pin 24 that protrudes upward. 22 is provided with a guide hole 25 corresponding to the guide pin 24.

  First, as shown in FIG. 2 (a), a surface coating film 12 of a fluorine film is provided so as to cover the bottom and side surfaces of the lower recess 23 of the lower mold 21 and extend to the upper surface of the lower mold 21. The uncrosslinked polymer composition R is provided in layers corresponding to the bottom and side surfaces of the recess 23. At this time, as the surface coating film 12, one having an adhesion imparting treatment on one surface is used, and the side subjected to the treatment is set to the inner uncrosslinked polymer composition R side. Examples of the adhesion-imparting treatment include sodium treatment and corona discharge treatment, but it is preferable to use a sodium-treated one from the viewpoint of durability of adhesion performance. At this time, a topping sheet in which the uncrosslinked polymer composition R is layered on the surface coating film 12 in advance may be used.

  Next, as shown in FIG. 2 (b), the fiber reinforcement 13 is placed on the cored bar (core material) 26. At this time, the fiber reinforcing material 13 may be used that has been subjected to an adhesion treatment such as an RFL treatment that is heated after being immersed in an RFL aqueous solution, or a material that has not been subjected to such an adhesion treatment. Also good. From the viewpoint of good workability of providing the fiber reinforcing material 13 on the cored bar 26, the fiber reinforcing material 13 is preferably a braid whose inner diameter is increased or decreased by axial compression or expansion. At this time, the fiber reinforcing material 13 may be provided on the core metal 26 and the uncrosslinked polymer composition may be covered. Further, the core reinforcement 26 may be covered with the uncrosslinked polymer composition and then covered with the fiber reinforcing material 13, or may be provided so as to further cover the uncrosslinked polymer composition. Thereby, the embedding position of the fiber reinforcement 13 can be set.

  Next, as shown in FIG. 2 (c), the metal core 26 provided with the fiber reinforcing material 13 is provided so as to be fitted onto the uncrosslinked polymer composition R in the lower recess 23 of the lower mold 21.

  Next, as shown in FIG. 3A, the uncrosslinked polymer composition R is provided in a layered manner so as to cover the cored bar 26 provided with the fiber reinforcing material 13 fitted in the lower recess 23 of the lower mold 21. Then, a surface covering film 12 of a fluorine film is provided so as to cover the upper surface and extend to the upper surface of the lower mold 21. Accordingly, a pair of surface coating films 12 are provided on the upper surface of the lower mold 21 so as to overlap each other. At this time, as the surface coating film 12, one having an adhesion imparting treatment on one surface is used, and the side subjected to the treatment is set to the inner uncrosslinked polymer composition side. At this time, a topping sheet in which the uncrosslinked polymer composition R is layered on the surface coating film 12 in advance may be used.

  Next, as shown in FIG. 3B, the upper die 22 is lowered, and the guide pin 24 is inserted into the guide hole 25 and guided to clamp the die. At this time, the mold temperature is, for example, 150 to 180 ° C., the mold clamping pressure is 0.2 to 1 MPa, and the holding time is 5 to 60 minutes. As a result, the crosslinking reaction of the uncrosslinked polymer composition R proceeds and the core body 11 is molded, and the surface coating film 12 is bonded to the core body 11 and integrally molded to cover the surface of the core body 11. The fiber reinforcing material 13 is embedded in the core body 11. Further, the surplus of the polymer composition flows from between the pair of surface coating films 12 between the lower mold 21 and the upper mold 22 to the mold-matching portion to form burrs B. As a result, the core body 11 with less internal distortion is formed. Furthermore, the surplus portion of the surface covering film 12 is also extended toward the end and similarly flows to the mold-matching portion to form the burrs B. Thereby, generation | occurrence | production of the wrinkle of the surface coating film 12 in the surface of the core 10 for shaping | molding will be suppressed.

  Then, as shown in FIG. 3C, the mold is opened, the molded body is taken out from the core molding die 20, the core metal 26 is pulled out from the molded body, and the burrs B are cut to form the molding core 10. Get. At this time, by cutting the burrs B, the molding core 10 is configured such that the surface coating film 12 is abutted at the top of the corner portion 11a of the core body 11.

  The obtained molding core 10 may be subjected to a secondary curing heat treatment with a heating temperature of 200 ° C. to 250 ° C. and a heating time of 1 to 16 hours. Thereby, the shrinkage resistance at the time of FRP molding can be improved.

  In the present embodiment, the molding core 10 has a rectangular cross-sectional shape, but is not particularly limited thereto, and may be other polygonal shapes such as a triangle and a trapezoid, Further, it may be oval or circular.

  Moreover, in this embodiment, although it was set as the molding core 10 which has a hollow part, it is not limited to this in particular, A solid thing may be sufficient. In this case, a core material of an uncrosslinked polymer composition may be used instead of the cored bar 26 at the time of manufacture.

  In the present embodiment, the fiber reinforcing material 13 is embedded in the inner layer of the core body 11. However, the present invention is not limited to this, and the structure is embedded in the intermediate layer of the core body 11. Furthermore, the structure embedded in the outer layer of the core main body 11 may be sufficient. In the latter case, the fiber reinforcing material 13 may be exposed on the surface without providing the surface coating film 12.

  INDUSTRIAL APPLICATION This invention is useful about the core for shaping | molding formed in the elongate shape used in the case of manufacture of the structural member made from FRP, and its manufacturing method.

It is a perspective view of the molding core which concerns on embodiment. (A)-(c) is explanatory drawing which shows the first half of the manufacturing method of the molding core which concerns on embodiment. (A)-(c) is explanatory drawing which shows the second half of the manufacturing method of the molding core which concerns on embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Core 11 for shaping | molding Core body 12 Surface coating film 26 Core metal (core material)

Claims (3)

A molding core formed in an elongated shape,
A core body formed of a viscoelastic material;
A cylindrical fiber reinforcement embedded in the core body along its length direction;
A molding core characterized by comprising: In the molding core according to claim 1,
A molding core, wherein the fiber reinforcing material is formed of a braid. A core for molding, comprising: a core body formed in an elongated shape and made of a material having viscoelasticity; and a cylindrical fiber reinforcing material embedded in the core body along its length direction. A manufacturing method of
A method for producing a molding core, wherein a core is covered with a cylindrical fiber reinforcing material, embedded in a core body forming material, and heated and pressurized.

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