JP6415885B2 - Method for producing perforated carbon fiber composite material - Google Patents

Description

The present invention relates to a method for producing a perforated carbon fiber composite material.

  Carbon fiber composites made by laminating a plurality of carbon fiber prepregs impregnated with resin and impregnated with carbon fiber, and integrated by hot pressing, have come to be used for members that require lightweight and rigidity. It was. The carbon fiber composite material may require holes depending on the product or the use site.

  Conventionally, as shown in (6-1) and (6-2) of FIG. 6, the drilling process of the carbon fiber composite material is performed by rotating carbon fibers from the surface of the carbon fiber composite material 61 while rotating the drill blade 71. The hole 63 is penetrated by being pushed into the composite material 61, and then the drill blade 71 is pulled out from the hole 63 as shown in (6-3) of FIG. Reference numerals 62A to 62D denote the respective layers.

  However, the layer 62A on the surface side of the carbon fiber composite material 61 is different from the inner intermediate layers 62B and 62C in that only the inner side is bonded to the other layer 62B, and there is no other layer on the outer side. The peel strength is lower than that of the intermediate layers 62B and 62C, and when the drill blade 71 is pulled out from the hole 63, the peripheral portion 64 of the hole 63 is made of the drill as shown in FIG. It is peeled off by the blade 71 and turns outward. In addition, the surface where the turn is generated moves smoothly, so that it becomes a defective product after painting. In addition, in order to remove the turned-up portion, the periphery of the turned-up portion must be scraped off with a file, which requires a great number of man-hours.

  In addition, in order to suppress the generation | occurrence | production of the burr | flash at the time of a punching process, what sticks a glass fiber reinforced resin skin material on both surfaces of a carbon fiber reinforced resin base material, and performs a punching process is proposed. However, in this case, there is a problem that the product becomes heavy due to the presence of the glass fiber.

JP-A-8-281508 JP 2009-023163 A

This invention is made | formed in view of the said point, Comprising: It aims at provision of the manufacturing method of the lightweight perforated carbon fiber composite material which is hard to produce a turn around the periphery of a hole .

The invention of claim 1 is a method for producing a perforated carbon fiber composite in which a hardened layer of a carbon fiber prepreg and a hardened layer of a porous prepreg are laminated and integrated to form a hole, the porous fiber comprising a foam at least one layer of porous prepreg of a thermosetting resin is impregnated into wood disposed between the carbon fiber prepreg, hot pressing and cured, the surface carbon fiber prepreg of the carbon fiber composite material during the hot press bending wherein the porous prepreg is compressed to form a recess, the inner wall surface of the recess carbon fiber is bent and arranged along the recess, the carbon fibers to the periphery of the recess consisting of the standing wall and cured at flexion while being And forming a hole in the recess.

According to a second aspect of the present invention, in the first aspect, the concave portion has a diameter equal to the diameter of the hole.
The invention of claim 3 is characterized in that, in claim 1 or 2, the foam has an open cell structure .
According to a fourth aspect of the present invention, in any one of the first to third aspects, the concave portion is circular, and the hole is formed in the through hole with a drill.

  According to the present invention, the concave portion on the surface of the carbon fiber composite material is formed by bending the surface inward by pressing the surface of the carbon fiber prepreg and compressing the internal porous prepreg during hot pressing. For this reason, the surface layer is hardened in a bent state by being pulled toward the back side at the periphery of the recess, and it is difficult to turn the periphery of the hole toward the surface when making a hole in the recess. In addition, since the front side layer is bent toward the back side at the peripheral edge of the concave portion, the rigidity is increased in shape, and the peripheral edge of the hole is difficult to be turned at the time of drilling. Accordingly, when the drill blade is pulled out from the hole, the peripheral edge of the hole is difficult to be turned, the post-processing man-hours for the peripheral edge of the hole can be reduced, and the appearance of the coating is improved. Furthermore, since a glass fiber layer for preventing the peripheral edge of the hole from being turned up (preventing burrs) is unnecessary, a lightweight punched product can be obtained.

It is sectional drawing of the hot press type | mold at the time of recessed part formation. It is sectional drawing of the carbon fiber composite material in which the recessed part was formed in the surface. It is sectional drawing which shows the time of drilling. It is a perspective view of the member for robot hands by which the hole was drilled with the drilling method of this invention. FIG. 5 is an enlarged cross-sectional view of 5-5 in FIG. 4. It is sectional drawing which shows the conventional drilling process.

Hereinafter, embodiments of the present invention will be described. In the method for producing a perforated carbon fiber composite material according to the present invention, a recess forming step is first performed.
In the recess forming step, as shown in FIG. 1, the laminate 10A in which at least one porous prepreg 31A is disposed between the carbon fiber prepregs 21A and 23A is hot-pressed, and the recess 11 is formed on the surface as shown in FIG. The formed carbon fiber composite material 10B is molded. Reference numerals 21 and 23 are layers in which the carbon fiber prepreg is cured, and reference numeral 31 is a layer in which the porous prepreg is cured.

The carbon fiber prepregs 21A and 23A are made of a carbon fiber fabric impregnated with a thermosetting resin. The carbon fiber woven fabric is excellent in light weight and high rigidity, and is particularly preferably a fabric in which the fibers are not only in one direction, for example, plain weave, twill weave, satin weave and three directions composed of warp and weft. A triaxial weaving made of yarn is suitable. The carbon fiber fabric preferably has a fiber weight of 50 to 600 g / m ² from the viewpoint of impregnation with a thermosetting resin and rigidity.

  The thermosetting resin impregnated in the carbon fiber fabric is not particularly limited, but in order to increase the rigidity of the carbon fiber composite material 10, the thermosetting resin itself needs to have a certain degree of rigidity, and an epoxy resin, It can be selected from the group consisting of phenolic resins, mixtures of epoxy resins and phenolic resins. When the carbon fiber composite material 10 is required to have flame retardancy, the thermosetting resin is preferably flame retardant. The phenol resin is suitable as a thermosetting resin impregnated in the carbon fiber fabric because the additive imparting flame retardancy can be reduced because of its composition and has good flame retardancy.

  The thermosetting resin is preferably impregnated in the carbon fiber fabric so that the resin weight ratio in the carbon fiber prepreg is 50 to 80%, particularly 55 to 70%. By setting it as the said resin ratio, lightweight property and rigidity can be made more favorable.

The porous prepreg 31A is obtained by impregnating a porous material with a thermosetting resin.
The porous material is not particularly limited, and examples thereof include foams and fiber products. As the foam, a foam having an open cell structure is suitable, and for example, a urethane resin foam, a melamine resin foam, a polyolefin (polyamide) resin foam and the like can be selected. Since the foam is open-celled, it can be impregnated with a thermosetting resin and can be molded with a high compression ratio. Specific examples of the fiber product include fibrils, yarns, piles, cotton-like materials, woven fabrics, knitted fabrics, nonwoven fabrics, nets, flocked fabrics, and cut products thereof. By selecting the above material as a porous material, compression molding is possible to a thickness in which carbon fiber fabrics are laminated. When the carbon fiber composite material is required to have flame retardancy, the porous material is preferably flame retardant, and the melamine resin foam has good flame retardancy, so it is suitable as the porous material. Is. The original thickness before compression of the porous material is set as appropriate, for example, 1 to 25 mm. Further, when the porous material is made of a foam, the foam preferably has a density before compression of 5 to 80 kg / m ³ from the viewpoint of easy compression, impregnation, light weight and rigidity.

  The thermosetting resin impregnated in the porous material is not particularly limited, but in order to increase the rigidity of the carbon fiber composite material, the thermosetting resin itself needs to have a certain degree of rigidity. It can be selected from the group consisting of resins, mixtures of epoxy resins and phenolic resins. When the carbon fiber composite material is required to have flame retardancy, the thermosetting resin is preferably flame retardant. Since phenol resin has good flame retardancy, it is suitable as a thermosetting resin impregnated in the porous material. Moreover, it is preferable that the thermosetting resin impregnated in the porous prepreg and the thermosetting resin impregnated in the carbon fiber prepreg are the same, and the occurrence of delamination is remarkably reduced by increasing the adhesion.

  In addition, the number of layers of the carbon fiber prepreg is at least two layers on the front surface and the back surface of the carbon fiber composite material, and may be more than that. The number of layers of the porous prepreg is at least one layer between the carbon fiber prepregs, and may be more than that. For example, at least one side is constituted by a laminate of two or more layers of carbon fiber prepregs, or two or more porous prepregs are provided between the carbon fiber prepregs, or further between two or more porous prepregs. A carbon fiber prepreg may be arranged. The number of layers of the carbon fiber prepreg and the number of layers of the porous prepreg are appropriately determined according to the use of the carbon fiber composite material.

  The hot pressing is performed by the lower hot pressing die 41 and the upper hot pressing die 42. A recess forming protrusion 43 is formed on the mold surface of the upper hot press mold 42. The recess forming protrusion 43 has a disk shape (columnar shape) with a predetermined protrusion thickness. The diameter a of the recess forming protrusion 43 is equal to the diameter b of the recess 11 to be formed. The standing wall of the projection 43 for forming the recess may be vertical or inclined, that is, tapered, but it is preferable to have the taper because the mold can be easily removed. The diameter c of the hole formed in the carbon fiber composite material is equal to the diameter b of the recess 11 to be formed. The diameter of the drill blade 51 is selected to be equal to the diameter b of the recess 11 to be formed. After drilling with the drill blade 51, when the blade 51 is pulled out, a meklet with carbon fibers cut off at the periphery of the diameter b 'of the bottom surface of the recess 11 to be formed is formed. At the same time that the blade 51 is pulled out, the mesh is formed so as to protrude along the upper hot press die direction and along the inner wall of the recess 11, but the depth of the recess vertical wall allows the surface of the carbon fiber composite to reach the surface. Never stick out. The diameter a of the projection 43 for forming the recess can be selected according to the drill standard. However, when a 5.25 mm or 6.75 mm hole is formed, the depth of the recess is 0.5 mm. good.

  The laminated body 10A composed of the carbon fiber prepreg 21A, the porous prepreg 31A, and the carbon fiber prepreg 23A is hot pressed (pressurized and heated) by bringing the lower heat press mold 41 and the upper heat press mold 42 close to each other. . The lower hot press die 41 and the upper hot press die 42 are heated to a temperature at which the thermosetting resin can be cured by heating means such as an electric heater.

  When the laminated body 10A is hot-pressed by the lower hot press die 41 and the upper hot press die 42, the carbon fiber prepreg 21A on the surface side is formed by the concave forming protrusion 43 of the upper hot press die 42 so that the laminated body 10A. The porous prepreg 31A is compressed while being pushed toward the back surface side of the substrate, and the concave portion 11 is formed on the surface. In this state, the thermosetting resin impregnated in the carbon fiber prepregs 21A and 23A and the porous prepreg 31A is cured, whereby the carbon fiber prepregs 21A and 23A and the porous prepreg 31A are integrated and shaped. The carbon fiber composite material 10B which is fixed and has the concave portion 11 shown in FIG. 2 formed on the surface is obtained.

  Next, a drilling process is performed. The drilling step is performed by a drill as shown in FIG. Reference numeral 51 in FIG. 3 denotes a drill blade. The drill blade 51 rotated as shown in (3-1) of FIG. 3 is pressed against the recess 11, and the drill blade 51 is pressed into the recess 11 as shown in (3-2) of FIG. The hole 13 penetrated to the back surface of the carbon fiber composite material 10B is opened. Thereafter, as shown in (3-3) of FIG. 3, the rotating drill blade 51 is pulled out from the hole 13. Reference numeral 10 denotes a carbon fiber composite material after drilling.

In the drilling process, the periphery of the recess 11 in which the hole is drilled is bent and hardened toward the back side of the carbon fiber composite material 10B during the hot pressing, so that the rigidity is increased by the bending. It is cured in a state of being bent and pulled toward the back side. Therefore, even if the drill blade 51 has a hole, the fiber length of the mesh is cut short, and when pulling out the drill blade 51 from the hole 13, the protrusion does not protrude to the periphery of the hole 13, A clean hole 13 is formed.
The diameter d of the drill blade 51 is equal to the diameter b of the recess and the diameter c of the hole 13 to be formed. Since the diameter d of the drill blade 51 is equal to the diameter b of the recess 11, a mecca is generated at the peripheral edge of the bottom surface of the recess without causing a mecca on the inner wall surface of the recess. Due to the depth of the standing wall of the concave portion, this meklet does not protrude from the surface of the composite molded article even if it becomes burrs on the upper side.

  4 and 5 show the carbon fiber composite material 10 in which the drilling process of the embodiment has been performed. The carbon fiber composite material 10 after drilling is used as a robot hand member attached to an arm portion of an industrial robot. The hole of the carbon fiber composite material 10 is a hole for passing an air blowing and / or suction path for supporting a transported object or the like transported by a robot, or an electric wiring path for various sensors, It is given to make a screw hole for mounting. The peripheral edge of the obtained hole 13 was a good one without any crevices. In addition, although the example which provided the through-hole was shown as embodiment to implement, the hole of this invention is not restricted to a through-hole, The hole which does not penetrate and the hollow hollowed out deeply may be sufficient.

Thus, according to the method for producing a perforated carbon fiber composite material of the present invention, the peripheral edge of the hole is difficult to turn up, the post-processing man-hours of the peripheral edge of the hole can be reduced, and the coating appearance can be improved. The present invention can be applied to various products composed of carbon fiber composite materials having holes. And since the member which becomes heavy, such as glass fiber, is not required in order to prevent the periphery of a hole from being turned over, a lightweight drilling processed product can be obtained.

DESCRIPTION OF SYMBOLS 10 Carbon fiber composite material after drilling 10A Laminated body which arrange | positioned porous prepreg between carbon fiber prepregs 10B Carbon fiber composite material with which the recessed part was formed in the surface 11 Recessed part 13 Hole 21A, 23A Carbon fiber prepreg 21, 23 Carbon fiber Hardened layer of prepreg 31A Porous prepreg 31 Hardened layer of porous prepreg 41 Lower heat press mold 42 Upper heat press mold 43 Projection for forming recess 51 Drill blade

Claims (4)

A method for producing a perforated carbon fiber composite in which a cured layer of a carbon fiber prepreg and a cured layer of a porous prepreg are laminated and integrated to form a hole,
At least one layer of porous prepreg of a thermosetting resin is impregnated into the porous material consisting of foam was placed between carbon fiber prepreg,
Heat press to cure ,
The carbon fiber prepreg is bent on the surface of the carbon fiber composite material during the hot pressing and the porous prepreg is compressed to form a recess,
The carbon fiber is bent and arranged along the recess to form the inner wall surface of the recess in which the carbon fibers to the periphery of the recess consisting of the standing wall cured at flexion,
A method for producing a perforated carbon fiber composite material, wherein a hole is formed in the recess. 2. The method for producing a perforated carbon fiber composite material according to claim 1, wherein the recess has a diameter equal to the diameter of the hole . The method for producing a perforated carbon fiber composite material according to claim 1 or 2, wherein the foam has an open-cell structure . The method for producing a perforated carbon fiber composite material according to any one of claims 1 to 3, wherein the concave portion is circular, and the hole is formed in the through hole with a drill.

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