JPH0976385A - Method for producing fiber-reinforced composite material having connecting holes - Google Patents

Abstract

(57) An object of the present invention is to provide a method for producing a fiber-reinforced composite material having a rivet or a connection hole for connecting with a screw and having a high resistance to a concentrated stress generated around the connection hole. SOLUTION: The thermoplastic resin to be impregnated in the unimpregnated reinforced fiber cloth is formed into a film state, the thermoplastic resin film and the unimpregnated reinforced fiber cloth are superposed, and the laminate is heated to a temperature not lower than the melting point of the resin film. Piercing the penetrating member, bending the warp and weft of the unimpregnated reinforcing fiber cloth around the penetrating member to escape, and impregnating the melted resin around the piercing penetrating member into the bent fiber around the penetrating member, The penetrating member is pulled out to solidify the resin, and the fibers at the piercing position are fixed in a bent state to form a connecting hole.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a thermoplastic fiber reinforced composite material having a rivet or a connecting hole for connecting with a screw, and more specifically to a concentrated stress generated around the connecting hole. The present invention relates to a method for producing a fiber-reinforced composite material having high resistance to heat.

[0002]

2. Description of the Related Art As a known prior art technically closest to the present invention, there is, for example, the one shown in FIGS. 1 and 2 on page 4 of JP-A-62-264896.

When a joining hole is provided in the fiber reinforced material, for example, when a hole is post-processed by drilling, the reinforcing fiber is cut by this drilling and the strength is reduced. Therefore, in the above-mentioned known example, in order to form the bonding hole without cutting the reinforcing fiber embedded in the fiber reinforcement, first, to the prepreg which is a material, the penetrator is pushed before the curing reaction and embedded in the material. A fiber-reinforced composite material having high-strength pores for bonding is formed by allowing the fibers to flow without damage to form pores of a desired diameter, and then heat-curing the composite material while holding the pores. It is designed to be manufactured.

[0004]

However, in such a conventional example, a so-called prepreg in which reinforcing fibers are pre-impregnated with epoxy resin or polyester resin which is a matrix resin is used. In this case, these resins have a high viscosity because they are in a state where a partial reaction called B stage has proceeded. Therefore, even if heating is used to reduce the viscosity, it is necessary to pierce the penetrator and bend the fibers to allow them to escape, as shown in FIG. 1 (b) on page 4 of JP-A-62-264896. Even if it is a unidirectional reinforcing material that faces in one direction and has no horizontal entanglement, if the reinforcing fibers are in the form of a cloth (cross) called plain weave or satin weave, the warp threads and the weft threads are intersected alternately. ,Have difficulty. This situation is even more difficult when PEEK resin or a thermoplastic resin such as polypropylene or nylon is impregnated. In other words, since these resins are solid at room temperature, it is impossible to pierce the penetrator, and heating these resins at the intersections of the warp and weft in the entire range that should be escaped by the puncture of the penetrator above the melting point. Then, it is necessary to make the resin into a starch syrup-like shape. Even if it can be heated well above the melting point, these resins have inherently high viscosities, so the fibers at the intersections are unlikely to shift, and if stabbed with force, the entire prepreg will largely warp and cannot be laminated flat.
In such a warped prepreg, even if the prepregs are stacked and pressed by a mold, the reinforcing fibers in the molding plate are sharply curved, and the strength of the obtained composite material is significantly reduced. , There was a problem.

[0005]

The present invention has been made by paying attention to such conventional problems. (1) A thermoplastic resin to be impregnated into a resin-unimpregnated reinforced fiber cloth is formed into a film. The thermoplastic resin film and the reinforcing fiber cloth are overlaid, and the laminated member is pierced with a penetrating member (made of metal or ceramic) heated to a temperature equal to or higher than the melting point of the resin film, and warp and weft of the reinforcing fiber cloth are formed. After bending the resin around the penetrating member and letting it escape, the molten resin around the piercing member is impregnated into the bent fiber around the penetrating member, and then the penetrating member is pulled out to solidify the resin and bend the fiber at the piercing position. It is fixed in the closed state to form a connection hole.

(2) Further, desirably, after the warp yarn and the weft yarn of the reinforcing fiber cloth are released by the penetrating member, subsequently,
The outer edge surrounding the formed hole and the outline of the shape to be formed are also traced with a heated iron to melt the film and impregnate the fiber to fix the fiber. By this step, when the laminate is cut into a predetermined shape for the next step of forming the laminate including the connecting holes, it is possible to prevent the warp and the weft of the fibers around the cut position from being frayed.

As described above, a predetermined number of laminates in which the fibers in the connection holes and the periphery thereof are fixed by the resin are prepared, and the connection holes and the periphery thereof are aligned and overlapped, and preferably inserted into the holes. The above-mentioned conventional problems can be solved by heating and pressurizing with a die equipped with a power pin to form a laminated molded plate.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION The first embodiment of the method for producing a fiber-reinforced composite material having connecting holes according to the present invention is a resin-impregnated reinforced fiber cloth and a film-like thermoplastic resin to be impregnated into the reinforced fiber cloth. A matrix resin is overlaid, and a penetrating member heated to a temperature equal to or higher than the melting point of the resin is pierced into this laminate to bend and escape the warp and weft of the cloth,
The resin around the penetrating member is melted and impregnated into the bent reinforcing fibers, and then the penetrating member is pulled out to cool and solidify the resin to form a hole fixed at the penetrating member piercing position. It is characterized in that it is formed and then the entire laminate is thermoformed.

According to the first embodiment, satisfactory molding can be performed without warping or wrinkling of the entire cloth.

The second embodiment of the method for producing a fiber-reinforced composite material having connecting holes according to the present invention is a resin-impregnated reinforced fiber cloth and a film of a thermoplastic matrix resin film to be impregnated into the reinforced fiber cloth. And piercing this laminate with a penetrating member heated above the melting point of the resin to bend and escape the warp and weft yarns of the cloth, and to melt the resin around the penetrating member to form the bent state. By impregnating the reinforcing fiber and then pulling out the penetrating member, a hole fixed at the penetrating member piercing position is formed, and a plurality of laminates having the hole are prepared, and these laminates are connected to each other. It is characterized in that the holes are aligned and stacked, and heat and pressure are applied for integral molding.

According to the second embodiment, even if the laminates to be integrally molded are laminated in multiple layers, the fibers in the molded product do not meander, and the fibers are not damaged. , Strength development becomes good.

The third embodiment of the method for producing a fiber-reinforced composite material having connecting holes according to the present invention is to stack a resin-unimpregnated reinforcing fiber cloth and a film-shaped thermoplastic matrix resin to be impregnated on the reinforcing fiber cloth. A piercing member heated to a temperature equal to or higher than the melting point of the resin is pierced into the laminate to bend and escape warp threads and weft threads of the cloth, and the resin around the penetrating member is melted to reinforce the reinforced fiber in the bent state. Then, the resin along the contour line is melted by a trowel to heat the contour line of the shape to be molded of the laminate to impregnate the fiber, and the fiber in the portion along the contour line is By fixing and then pulling out the penetrating member, a hole fixed at the penetrating member piercing position is formed, the laminate is cut along the shape contour line, and the cut-formed laminate is formed. Prepare several sheets, these laminates stacked together those connection hole, characterized in that integrally molded by heating and pressing.

According to the third embodiment, since the contour portion of the shape cut out by taking the material is also impregnated and fixed with the resin, the warp and the weft of the fibers are prevented from fraying at the time of cutting.

A fourth embodiment of the method for producing a fiber-reinforced composite material having a connecting hole according to the present invention is the method according to any one of the first to third embodiments, in which a plurality of laminates are stacked. It is characterized in that the connecting hole is formed by using a die provided with a pin that fits into the hole formed by the penetrating member and a hole that fits into this pin when performing the heat and pressure molding.

According to the fourth embodiment, since the hole formed by the penetrating member is fixed and held, when the laminates are stacked and formed in multiple layers, the laminates can be accurately and accurately placed in the mold. It can be arranged efficiently and the connecting hole can be easily formed.

[0016]

The present invention will be described in more detail with reference to the following examples.

Example 1 As a reinforcing fiber cloth, a glass fiber plain weave cloth (mass: 170 g / mm ² , thickness :)
0.2 mm, yarn density length: 16 yarns / 25 mm, width: 15 yarns / 25 mm) were cut into 208 × 108 mm sheets (the glass cloth longitudinal direction was parallel to the short side). Next, as a thermoplastic resin film, 31 sheets of polyamide 66 film (thickness 0.1 mm) were cut into the same size. The cut glass fiber plain weave cloth and the thermoplastic resin film were dried at 80 ° C. for 5 hours.

From each of these, one cloth 1 and one film 2 were stacked as shown in FIG. With respect to this laminate, positioning is performed at a pitch of 44 mm on a line parallel to each long side of the cloth 1 and 30 mm inside from the end and parallel to the short side,
Those positions were defined as hole forming positions. At the hole forming positions, as shown in FIG. 2, a pointed round bar member (apex angle 30 °) 3 which is a penetration member made of φ12 metal or ceramic,
Taking into consideration the melting point of polyamide 66, 260 ° C., it is pierced by heating it to 280 ° C., while supporting the lower surface with the pedestal 4 having holes slightly larger than φ12, and piercing the warp and weft of the glass fiber plain weave cloth around the penetrating member 3. The resin film 2 is melted and impregnated into the fibers of the cloth 1 while being deflected to escape, and the penetrating member is pulled out, and the heating penetrating member is pulled out, whereby the hole portion is cooled and fixed, and as a result, φ12
Holes 9 were formed.

This operation was repeated for the remaining cloths and films. All the laminates were stacked by aligning the centers of the holes 9 so that the surfaces of the cloth 1 and the film 2 of the laminate in which the cloth 1 and the resin film 2 were combined were alternately superposed (multilayer laminate).

A mold having a cavity capable of being molded into a flat plate having a long side 210 and a short side 110 mm is preheated to 180 ° C.,
The above multi-layer laminate is charged into this, and the temperature is raised to 240 ° C.,
As deaeration operation at this temperature, pressurization for 2 minutes at a surface pressure of 600 kPa and pressure reduction for 1 minute were repeated 3 cycles. After that, the surface pressure was increased to 2000 kPa and the temperature was raised to 290 ° C., and then 1
Hold for 0 minutes to cool the mold, about 3.8mm from the mold
A multi-layer laminated molding having a thickness was taken out.

A strip specimen 5 having a width of 42 mm is cut out from the multilayer laminated molded product parallel to the short side with the center of the piercing hole 9 of the penetrating member as a center line, and a φ10 drill is post-processed concentrically with the hole 9 to form a hole. Was done. To reinforce the periphery of the hole, as shown in FIG. 3, M10 plain washers 6 were adhered to both sides with an epoxy resin. At this time, roughening and degreasing of the periphery of the hole 9 and the bonded portion of the flat washer 6 were performed, and after applying the epoxy resin to the interface, the bolt 7 and the nut 8 were used to 4.2 kg
While tightening from both sides with the torque of fm, the strip sample 5
Was cured by heating. The strip test piece 5 was pulled between both bolts 7, 7 with a tensile tester at a speed of 0.5 mm / min to measure the breaking strength between the bolts. As a comparison, a sample was prepared and a tensile test was performed by the same operation except that the penetration member piercing operation of φ12 was omitted, and the comparison was performed. The results are shown in Table 1. As is clear from the table, the effect of improving the strength by the fiber escape by the penetrating member was recognized.

[0022]

[Table 1]

In the above embodiment, the resin-impregnated glass fiber cloth 1 and the resin film 2 to be impregnated into the glass fiber cloth 1
And the penetrating member 3 heated above the melting point of the resin film 2 is pierced, the warp yarns and the weft yarns of the glass fiber cloth 1 are deflected around the penetrating member 3 and escaped, and the resin film 2 at that portion is released there. It is melt impregnated. Then, since the resin is cooled and solidified by pulling out the penetrating member 3, its shape is fixed. Further, in Example 2 described below,
Subsequent to the piercing and fixing of the penetrating member, the heating iron applied to the contour line of the shape to be cut out later for material sampling similarly melt-impregnates and fixes the contour line.

Example 2 In this example, the effect of the fiber-reinforced composite material of the present invention was confirmed by applying it to a torsion torque transmission joint. 4 and 5 show a torsion torque transmitting joint 11 having a connecting hole formed according to the present invention. The connecting holes 12, 12, 12 are connected to the three-pronged yoke of the drive shaft with bolts and nuts. Also, the connecting holes 13, 1
3 and 13 are connected to the driven shaft, and torque is transmitted from the drive shaft to the driven shaft. The periphery of these connecting holes is thickened to form a bolt hole reinforcing portion 14 for reinforcement, and a flat washer 6'is adhered to these connecting holes for reinforcement.

The manufacture of the joint having such a structure will be described with reference to FIGS. As in Example 1, one glass fiber cloth overlaid with one polyamide 66 film,
While supporting the lower surface with a pedestal that has a hole slightly larger than φ10, it has a conical tip with an apex angle of 30 °.
The rod member (penetrating member) is pierced while being heated to the melting point of polyamide 66 or higher, so that it comes to the apex of the hexagon at 60 ° intervals on the circumference of φ108, and one of the diagonals is glass fiber. Φ1 to fit in the vertical direction of the cloth
Six holes 9'of 0 were formed and fixed. Φ including these 6 holes
150 discs were cut out. Prior to this cutting, a polyamide 66 film on the circumference of φ150 was melted with a trowel heated to a temperature above its melting point, impregnated into a cloth and solidified to prevent fraying of warp and weft due to cutting into a disc shape. Prepare 15 of these and, as shown in FIG.
Divided into three sheets, these three sheets are a laminate in which the longitudinal direction of the fiber is oriented (60 °, 0 °, −60 °) when the longitudinal direction of the cloth is 0 °, and the glass cloth and the resin film are alternately laminated. Five sets of 21 were prepared.

On the other hand, in order to reinforce the periphery of the bolt hole, the warp yarn and the weft yarn were bent to escape in the center by the above-mentioned method, and 72 laminates fixed with polyamide 66 at that position were cut out.
Of these 36 sheets, the direction of fibers in the sector was 45 ° with respect to the target axis of the sector, and the remaining 36 sheets were oriented at -45 °. Further, the fan-shaped contour line is formed by melting the polyamide 66 film in order to prevent fiber fraying accompanying cutting.
Pre-impregnated and fixed. As shown in FIG. 8, one set each of 45 ° and −45 ° was taken from each of them to form a set of two fan-shaped members 22, and 36 sets of them were manufactured. These are used to make a multilayer laminate.

That is, six sets of fan-shaped members 22 are taken and the sets are arranged one by one so that the target axes are arranged on the circumference of the pitch circle φ108 at an angle of 60 ° so as to face the pitch circle center. The φ150 discs (laminate) 21 of the three discs are oriented with the longitudinal direction of any one of the three discs in the direction connecting the fan-shaped hole center and the pitch circle center, the hole centers are overlapped, and the film is heated with a trowel. Are melted and solidified in places and temporarily fixed, and six fan-shaped sets are superposed on each other in the same direction as the above-mentioned six sets with the hole centers aligned and temporarily fixed. In this manner, six sets of fan-shaped members 22 are laminated on the apex of the hexagon (bolt hole reinforcing portion) with five sets of the disc-shaped laminate 21 sandwiched therebetween, and discs other than the apex are disc-shaped. Make and place a multi-layered laminate in which only five laminates 21 are stacked.

On the other hand, an upper die and a lower die (a fan-shaped engraving on the side facing the multi-layer laminate and a φ of the multi-layer laminate formed by a penetrating member on a pitch circle at the center of the fan-shaped engraving.
A pin to be inserted into 10 holes and a hole to be fitted into the pin), and a metal mold having a cylindrical side mold.
Raise the temperature to ℃. Here, the above-mentioned multi-layered laminate is put into a mold by piercing the hole 9'with a pin, and heated to 250 ° C. Surface pressure 1000 kPa, pressurization 2 minutes, depressurization 1 at this temperature
After repeating the deaeration operation for 3 minutes, the temperature is 290 ° C.,
The surface pressure was raised to 2000 kPa and the pressure was maintained for 10 minutes. After the holding, the mold was cooled, and a disk-shaped molded product having a plate thickness of the bolt hole reinforcing portion of about 4 mm and an intermediate portion of about 2 mm was obtained from the mold. Post-processing such as cutting out the central portion of this molded product into a substantially hexagonal shape was performed, and then a flat washer of M10 was bonded to the bolt hole reinforcing portion with an epoxy resin.

On the other hand, as a comparative example, a molded product was obtained by the same operation except that the punching by the penetrating member of φ10 was omitted (thus, the pin in the mold was also removed) when the multilayer laminate was manufactured. In this comparative molded product, a flat washer was adhered after adding a hole drilling process with a φ10 drill at a position corresponding to the hole drilling by the penetrating member. Both are adjacent to each other at the drive axis,
Attach it to the trifurcated yoke of the driven shaft with M10 bolt nut.
The torsional breaking strength was measured. The results are shown in Table 1. An improvement in strength was observed in the product according to the present invention which was preliminarily drilled with a penetrating member and maintained by a pin attached to a mold even during laminated molding.

In each of the above embodiments, the use of glass fiber cloth is described, but the type of fiber is not limited to this, and carbon fiber, alumina fiber, alumina-silica fiber, silicon carbide fiber, metal Inorganic fibers such as fibers and organic fibers may be used as long as they have a higher melting point than the resin film to be combined, such as para-aramid fiber and polyphenylene sulfide fiber. Further, the form is not limited to plain weave, but can be applied to a product in which warp yarns such as satin weave and twill weave are restrained to some extent due to weft yarns. The fiber direction at this time is also not limited to the example and may be arbitrary. Further, as the matrix resin with which these fibers are impregnated, any thermoplastic resin having a melting point lower than that of the above-mentioned reinforcing fibers can be applied. For example,
Examples thereof include polyamide, polyester, polypropylene, polyethylene, polycarbonate, polyetherimide, polyphenylene sulfide, and polyether ether ketone, and the form thereof is not limited to a film and may be a woven fabric made of a thread made of these resins.

[0031]

As described above, according to the present invention, the warp yarns and the weft yarns of the reinforcing fiber cloth pierce the penetrating member in a resin-unimpregnated state, and then impregnated with the resin to form the fiber. Since the fiber easily escapes and bends and escapes without damaging the fiber, the connecting hole can be formed without warping or wrinkling on the entire cloth. Therefore, even if the laminate is laminated in multiple layers, the fibers in the molded plate do not meander and the fibers are not damaged, and the strength is improved. Also,
Since the hole formed by the penetrating member is fixedly held, it can be properly arranged also on the pin in the mold that forms the bolt hole when forming from the multilayer laminate. Furthermore, since the contour of the shape cut out by collecting the material is also fixed by impregnation,
The effect is that there is no fraying of warp and weft when cut out.

[Brief description of drawings]

FIG. 1 is a perspective view for explaining a first embodiment of the present invention, and is a view for explaining a procedure for producing a strip sample of a fiber-reinforced composite material according to the present invention.

FIG. 2 is an explanatory view of making holes in a fiber-reinforced composite material by a penetrating member.

FIG. 3 is an assembly diagram of a strip test piece for a tensile test.

FIG. 4 is a front view of a joint using the fiber-reinforced composite material according to the present invention for explaining the second embodiment of the present invention.

FIG. 5 is a side view of a joint using the fiber-reinforced composite material according to the present invention for explaining the second embodiment of the present invention.

FIG. 6 is a front view of a disk-shaped laminate that constitutes the joint.

FIG. 7 is an exploded perspective view of the disc-shaped laminate.

FIG. 8 is a front view of a fan-shaped member that constitutes the joint.

[Explanation of symbols]

 1 Glass Fiber Cloth (Reinforcing Fiber Cloth) 2 Polyamide 66 Film (Thermoplastic Resin Film) 3 Penetrating Member 4 Cradle 5 Strip Sample 6,6 'M10 Plain Washer 7 M10 Bolt 8 M10 Nut 9,9' Hole 11 Joint 12 Connection hole 13 Connection hole 14 Bolt hole Reinforcing part 21 Three-piece φ150 disc-shaped laminate 22 Two-piece fan-shaped member

Claims (4)

[Claims] 1. A reinforcing fiber cloth not impregnated with a resin and a film-shaped thermoplastic matrix resin to be impregnated on the cloth are superposed, and a piercing member heated to a temperature higher than the melting point of the resin is pierced into the laminate to form a cloth of the cloth. The warp yarn and the weft yarn are bent and released, and the resin around the penetrating member is melted and impregnated in the bent reinforcing fiber, and then the penetrating member is pulled out to cool and solidify the resin. Form a hole fixed at the penetrating member piercing position,
After that, the method for producing a fiber-reinforced composite material having a connecting hole, characterized in that the entire laminate is heat-molded. 2. A non-resin-impregnated reinforcing fiber cloth and a film-shaped thermoplastic matrix resin to be impregnated on the cloth are superposed, and the laminate is pierced with a penetrating member heated to a temperature higher than the melting point of the resin. The warp yarn and the weft yarn are bent and released, and the resin around the penetrating member is melted and impregnated in the bent reinforcing fiber, and then the penetrating member is pulled out to be fixed at the penetrating member piercing position. Fiber reinforced with connecting holes, characterized in that a plurality of laminates having the holes are formed, a plurality of laminates having the holes are prepared, the laminates are stacked together with the connecting holes, and heated and pressed to be integrally molded. Manufacturing method of composite material. 3. A reinforcing fiber cloth not impregnated with a resin and a film-like thermoplastic matrix resin to be impregnated on the cloth are superposed, and the laminate is pierced with a penetrating member heated to a temperature higher than the melting point of the resin to form a cloth. The warp yarn and the weft yarn are bent and released, and the resin around the penetrating member is melted and impregnated into the bent reinforcing fibers, and subsequently, the contour line of the shape to be formed of the laminate is heated by a trowel. By impregnating fibers by melting the resin along the contour line,
By fixing the fiber in the portion along the shape contour line, and then by pulling out the penetrating member, a hole fixed at the penetrating member piercing position is formed, and the laminate is cut along the shape contour line. A method for producing a fiber-reinforced composite material having a connection hole, characterized in that a plurality of the cut-molded laminates are prepared, the connection holes of these laminates are aligned and stacked, and heated and pressed to integrally mold the laminates. . 4. When stacking a plurality of laminates and heat-pressing them, molding is performed by using a die provided with a pin that fits a hole formed in the penetrating member and a hole that fits into this pin. The connecting hole is formed by
5. A method for producing a fiber-reinforced composite material having a connecting hole according to any one of 3 to 3.