JP7114056B2 - A method for manufacturing a fiber-reinforced resin bolt and a fiber-reinforced resin fastening member. - Google Patents

Description

TECHNICAL FIELD The present invention relates to bolts and nuts made of fiber-reinforced resin, and methods of manufacturing these fastening members.

Conventionally, bolts and nuts are essential fastening elements used in a wide range of industrial fields such as the automobile industry, the aircraft industry, and the medical equipment industry. Metals are mainly used as materials for these bolts and nuts from the viewpoint of strength characteristics and cost.

However, metal bolts and nuts are heavy, rust easily, and do not transmit X-rays. Therefore, various fiber-reinforced resin nuts and bolts have been proposed in place of metal nuts and bolts. For example, Non-Patent Document 1 discloses a technique of manufacturing a fiber-reinforced resin round bar in which fibers aligned in the axial direction are impregnated with a synthetic resin, and then cutting threads using a tool. there is

As a similar technique, Patent Document 1 discloses a first fiber-reinforced structure in which a first fiber member is embedded in a first base material made of synthetic resin to increase the strength of the first base material. A bolt made of a fiber-reinforced resin material that is made of a resin material and configured to fasten an object to be fastened to the object to be fastened by screwing it with a nut, and to reduce fluctuations in axial force due to changes in magnetic field or temperature, The fiber reinforced material, wherein the first fiber member in the shaft portion of the fiber-reinforced resin material bolt is a plurality of long fibers arranged along the axial direction of the fiber-reinforced resin material bolt. A resin material bolt and the like are disclosed.

Further, Patent Literature 2 discloses a technique for producing an injection-molded article of carbon fiber reinforced polyester resin using short fibers or powdery fibers. Furthermore, by arranging the fibers in a plane perpendicular to the axis, the strength of the threaded portion of the bolt and nut is particularly enhanced. Alternatively, a plastic bolt and nut is disclosed in which fibrous reinforcing materials oriented radially in the axial direction of the nut are embedded.

Similarly, in Patent Document 4, in a fiber-reinforced synthetic resin bolt in which a plurality of fibers are arranged substantially parallel in the axial direction of the bolt, the fibers are arranged in a plane substantially perpendicular to the bolt axis. Disclosed is a fiber-reinforced synthetic resin bolt in which are arranged.

JP-A-09-254266 JP 2016-888073 A JP-A-07-217629 JP-A-2003-56536

Yoshihiko Mukai, Shin Nishimura, "Fatigue strength of FRP bolts at room temperature and 77K", Materials, Vol.39, No.438(1990), pp.266-270

However, in the technology of Patent Document 1 and Non-Patent Document 1, the reinforcing fibers forming the thread are cut by cutting, so if a large shearing force is applied to the thread, it is easily chipped. There is a drawback. Moreover, in the technique disclosed in Patent Document 2, since short fibers or powdery fibers are used, there is a problem that the reinforcing function of the resin deteriorates.

Furthermore, in the techniques of Patent Documents 3 and 4, pressure is applied after manufacturing a core material shaped like a brush for cleaning bottles, or molding a cylindrical body composed of horizontal fibers. Problems have been pointed out that the process is complicated, such as the process being planted on a vertical fiber core material that is inserted by force, and that high-density fibers cannot be filled in the threads.

The problem to be solved by the present invention is to cope with the above-mentioned problems, and the strength of the thread is improved by arranging the fiber material in a plane perpendicular to the axis by a simple method. An object of the present invention is to provide a fiber-reinforced resin bolt and nut, and a method for manufacturing these fastening members.

In order to solve the above problems, the present invention takes the following technical measures.
That is, the invention according to claim 1 includes a rod-shaped core material, a cylindrical fiber reinforcement material arranged around the rod-shaped core material with the core material as an inner axis, and then the fiber reinforcement material being the axis of the core material. A fibrous material of the fiber reinforcement arranged in a plane perpendicular to the axial direction of the core material obtained by folding in a bellows shape along the direction, and a base material impregnated with the fibrous material synthetic resin as a material, and further, the screw thread formed at a predetermined position is constituted by the structure of the fibrous material of the fiber reinforced material ,
By adjusting the folding width in the axial direction when the fiber reinforcing material is folded into a bellows shape along the axial direction of the core material to a predetermined interval, The height of the fibrous material is constantly changing,
The folding width is adjusted by adjusting the winding pitch of the micro-diameter thread spirally wound on the surface of the fiber reinforcement to a predetermined interval, and using each of the micro-diameter threads as a starting point, the fiber reinforcement is folded in a bellows shape in the axial direction of the core material .

Further, the invention according to claim 2 is the fiber-reinforced resin bolt according to claim 1 , characterized in that a fiber-reinforced resin hollow rod or solid rod is used as the core material. there is

Further, the invention according to claim 3 provides a step of arranging a rod-shaped core material and a cylindrical fiber reinforcement around the rod-shaped core material with the core material as an inner axis; A step of arranging the fibrous material in a plane perpendicular to the axial direction of the core material by folding it in a bellows shape along the axial direction of the core material; and a step of impregnating the fibrous material with a synthetic resin as a base material. , forming a thread in a predetermined range of the textile so that the thread is formed by the structure of the textile ,
When the fiber reinforcing material is folded into a bellows shape along the axial direction of the core material, by adjusting the folding width in the axial direction to a predetermined interval, Constantly changing the height of the textile in
The folding width is adjusted by adjusting the winding pitch of the micro-diameter yarn spirally wound on the surface of the fiber reinforcement material to a predetermined interval, and starting from each of the micro-diameter yarns, the fiber reinforcement A method for manufacturing a fiber-reinforced resin fastening member, characterized in that the material is folded in a bellows shape in the axial direction of the core material .

The invention according to claim 4 is the method for manufacturing the fiber-reinforced resin fastening member according to claim 3 , wherein a fiber-reinforced resin hollow rod or solid rod is used as the core material. there is

According to the fiber-reinforced resin bolt and nut of the present invention, by arranging the fiber material in the plane perpendicular to the shaft by a simple method, high resistance to the shearing force applied to the thread can be obtained. In addition, it is lightweight, and performance such as excellent X-ray transparency can be obtained. These bolts and nuts can be manufactured by the manufacturing method of the present invention.

Furthermore, by adjusting the folding width of the bellows shape and continuously changing the size of the fiber material, it is possible to easily adjust even the parts having different diameters, such as the head part and the screw part of a bolt, for example. It becomes possible to manufacture to According to the present invention, a fiber-reinforced resin hollow rod or a solid rod is used as the core material, and the folded fiber material is integrated with the synthetic resin. can do.

It is an example figure which showed the manufacturing process of the bolt and nut (fastening member) made from a fiber reinforced resin which concern on this invention. FIG. 2 is a diagram showing a state in which a fiber reinforcing material is arranged in a core material among details of a manufacturing process of a fiber reinforced resin fastening member (bolt and nut) according to the present invention. FIG. 4 is a diagram showing a state in which fine-diameter threads are wound around the surface of the fiber reinforcement material, among the details of the manufacturing process of the fiber-reinforced resin fastening member (bolt and nut) according to the present invention. Among the details of the manufacturing process of the fiber-reinforced resin fastening member (bolt and nut) according to the present invention, it is a diagram showing a state in which a micro-diameter thread is wound on the surface of the fiber-reinforced material (the winding pitch is changed in the middle). be. FIG. 4 is a diagram showing a state in which a portion of the fiber reinforcing material is folded into a bellows shape, among the details of the manufacturing process of the fiber-reinforced resin fastening member (bolt and nut) according to the present invention. Among the details of the manufacturing process of the fiber-reinforced resin fastening member (bolt and nut) according to the present invention, it shows a state in which the folded width of the fiber reinforcement is adjusted and the size of the fiber of the fiber reinforcement is changed. It is a diagram. Among the details of the manufacturing process of the fiber-reinforced resin fastening member (bolt and nut) according to the present invention, FIG. be. FIG. 2 is a diagram showing a state in which a carbon fiber braid is arranged on the surface of a fibrous material made of a fiber reinforced material folded in a bellows shape, among the details of the manufacturing process of the fiber reinforced resin fastening member (bolt and nut) according to the present invention. is. FIG. 4 is a diagram showing a state in which a resin-impregnated molded body (for nuts) is produced by a mold, among the details of the manufacturing process of the fiber-reinforced resin fastening member (bolt and nut) according to the present invention. FIG. 4 is a diagram showing a state in which a resin-impregnated molded body (mainly for bolts) is manufactured by a mold, among details of the manufacturing process of the fiber-reinforced resin fastening member (bolt and nut) according to the present invention. The fastening member used in the performance verification experiment of the fiber-reinforced resin fastening member (bolt and nut) according to the present invention, (a) is an M12 hexagonal nut, (b) is a locking nut, and (c) is an M12 hexagonal bolt. showing. FIG. 2 is a microscopic view showing a cross section of a screw thread in a hexagonal nut, which is a fiber-reinforced resin fastening member according to the present invention. 1 is an X-ray transmission image of a member obtained by combining a bolt and a nut made of fiber-reinforced resin according to the present invention and hydroxyapatite.

Next, an embodiment of a fiber-reinforced resin bolt and nut (fiber-reinforced resin fastening member) according to the present invention and a method for manufacturing these will be described with reference to the drawings.
FIG. 1 is an example diagram showing the manufacturing process of the fiber-reinforced resin bolt and nut (fastening member) according to the present invention, and FIGS. ) is an example diagram showing a manufacturing process. Also, 10 is a fiber reinforced resin bolt, 12 is a core material, 14 is a fiber reinforcement material, 16 is a bellows-shaped fiber reinforcement material, 20 is a thread, 22 is a head portion, 24 is a screw portion, and 26 is a microdiameter. 28 is a molded body, 29 is a resin-impregnated molded body, 30 is a mold, and 32 is a fiber-reinforced resin nut.

First, as in the manufacturing process shown in FIG. 1, the fiber-reinforced resin bolt 10 in this embodiment includes a rod-shaped core material 12 and a cylindrical fiber-reinforced material around the core material 12 as an inner axis. 14 (FIG. 1(a)), and then the fiber reinforcing material 14 is folded along the axial direction of the core material 12 in a bellows shape, so that the fibrous material of the fiber reinforcing material 14 is folded into the core material 12. It is arranged in a plane perpendicular to the axial direction (FIGS. 1(c) and 1(d)), and the synthetic resin as the base material is impregnated into the fibrous material of the fiber reinforcement 14, and further A screw thread 20 is formed at a predetermined position by the structure of the fibrous material of the fiber reinforcing material 14 (FIG. 1(f)).

1, the fiber-reinforced resin nut 32 in the present embodiment includes a rod-shaped core material 12 and a cylindrical fiber-reinforced material around the core material 12 as an inner shaft. 14 (FIG. 1(a)), and then the fiber reinforcing material 14 is folded along the axial direction of the core material 12 in a bellows shape, so that the fibrous material of the fiber reinforcing material 14 is folded into the core material 12. It is arranged in a plane perpendicular to the axial direction (FIGS. 1(c) and 1(d)), and the synthetic resin as the base material is impregnated into the fibrous material of the fiber reinforcement 14, and further , and a threaded hole is formed in the threaded hole, and a screw thread is formed by the structure of the fibrous material of the fiber reinforcing material 14 (FIG. 1(f)).

In this embodiment, after the step of impregnating the synthetic resin, it is processed into a predetermined shape using a mold 30 as shown in FIG. 1(e). Furthermore, in this embodiment, as shown in FIG. thread 26 is wound spirally. By winding the fine-diameter threads 26 , it becomes easy to fold the reinforcing fiber material 14 along the axial direction of the core material 12 in a bellows-like shape using these threads as starting points.

Next, an embodiment of the fiber reinforced resin bolt 10 and the fiber reinforced resin nut 32 will be described in detail together with an embodiment of a method for manufacturing the fiber reinforced resin bolt and nut (fiber reinforced resin fastening member). In this embodiment, carbon fiber is used as the fiber reinforcing material, and epoxy resin is used as the synthetic resin of the base material.

First, as shown in FIG. 2, a core material 12 and a cylindrical fiber reinforcing material 14 are arranged around the core material 12 with the core material 12 as an inner axis. Here, a plurality of fiber reinforcing materials 14 may be combined (for example, a flat carbon fiber thread is combined with a carbon fiber braid). A hollow rod made of carbon fiber reinforced resin or a solid rod may be used as the core material 12 .

Subsequently, in the present embodiment, as shown in FIG. 3, a micro-diameter thread 26 (for example, a nylon line with an average diameter of 0.128 mm) is helically wound on the surface of the fiber reinforcing material 14 . Here, in order to constantly change the height of the fibers of the fiber reinforcing material 14 in the direction perpendicular to the axial direction of the core material 12, as shown in FIG. The folding width in the axial direction when folding the reinforcing fiber material 14 in the bellows shape along the axial direction of the core material 12 may be adjusted by changing it in the middle.

Next, in the present embodiment, as shown in FIG. 5 , the fiber reinforcement 14 is folded into a bellows shape starting from the micro-diameter threads 26 wound around the surface of the fiber reinforcement 14 . A molded body 28 is produced in which fibers are arranged in a plane perpendicular to the axial direction of the core material 12 (accordion-like fiber reinforcing material 16). As shown in FIG. 6, by adjusting the folding width of the bellows shape, it is also possible to manufacture a molded body 28 in which the size of the fiber material of the fiber reinforcing material 14 after folding is changed (in the figure, A head portion 22 (large) and a screw portion 24 (thin) of the fiber-reinforced resin bolt 10 .

In addition, in FIG. 6, the head portion 22 (large) may be processed for use as a nut. Moreover, as shown in FIGS. 7 and 8, other types of fiber reinforcing materials may be arranged on the surface of the fiber material of the fiber reinforcing material 14 after being folded, if necessary. That is, in FIG. 7, a continuous carbon fiber bundle is wound, and in FIG. 8, a carbon fiber braid is arranged.

Subsequently, after impregnating the fibrous material of the fiber reinforcing material 14 of the manufactured molded body 28 with a synthetic resin, a mold 30 is used to form the nut into a predetermined shape as shown in FIG. As shown, the bolt is manufactured in a predetermined shape or a shape close to it (in FIGS. 9 and 10, a resin-impregnated molded body 29 with only the external appearance excluding the thread 20 is manufactured). At this time, the nut or bolt may be manufactured directly, or may be processed into a predetermined shape including threads by cutting or the like later. By adopting such a process, the threads 20 are formed by the composition of the fibers of the fiber reinforcing material 14 arranged in a plane perpendicular to the axial direction of the core material 12 .

Experimental results for verifying the performance of the fiber-reinforced resin fastening members (nuts and bolts) according to the present invention will be described below. Here, as shown in FIG. 11, (a) M12 hexagonal nut, (b) locking nut, and (c) M12 hexagonal bolt were manufactured and used. Specifically, for (a) and (b), configuration A: braid, configuration B: braid + flat yarn, configuration C: braid + flat yarn composed of fiber bundles with a smaller diameter than configuration A, and for (c) , Configuration A: Only a braid was produced.

First, FIG. 12 shows the result of observing the cross section of the thread in the hexagonal nut. It was confirmed that in each of the configurations A, B, and C, the screw thread was composed of a fibrous structure in the plane perpendicular to the axis. Subsequently, a high-strength metal bolt was attached to the hexagonal nut, placed in a load tester, and pulled at a speed of 3 mm per minute to measure the minimum tensile strength of the hexagonal nut. Table 1 shows the results. It was found that any configuration has a tensile strength of 36 kN (approximately 3.7 tons) or more.

Next, attach a high-strength metal bolt to the hexagonal nut, place it in a torsion tester (tightening tester), and twist it at a rotational speed of 4 rpm to measure the torsional breaking torque and maximum axial force of the hexagonal nut. did. Table 2 shows the results. It was confirmed that, regardless of the configuration, the nut had a high breaking torque and a maximum axial force, and together with the tensile strength characteristics, was a nut that was sufficiently excellent in practical use.

Furthermore, a high-strength metal bolt was attached to the locking nut, placed in a load tester, and pulled at a speed of 3 mm per minute to measure the minimum tensile strength of the locking nut. Table 3 shows the results. It was found that any configuration had a tensile strength of 39 kN (about 4.0 tons) or more.

Subsequently, in the locking nut, the initial tightening axial force of the convex nut was set to 20 kN, and the initial tightening torque of the concave nut was set to 30 Nm. Table 4 shows the results of measuring the retention of axial force after 2000 cycles. It has been confirmed that, regardless of the configuration, a good locking effect can be obtained because the axial force retention rate is 75% or more.

Next, the X-transmittance of the combination of locking nuts and bolts and hydroxyapatite, which is a bone seed, was compared using an X-ray CT apparatus under the conditions of a tube voltage of 60 kV and a tube current of 20 μA. is shown in FIG. Compared to hydroxyapatite, good X-ray transparency is obtained, and the fiber-reinforced resin fastening member (nut, bolt) according to the present invention is suitable for medical equipment and medical instruments that require X-ray transparency. It was confirmed that the application was effective.

Although it is not particularly limited, in place of metal nuts and bolts, for example, medical equipment (X-ray CT, MRT) that requires weight reduction of the body / vehicle body, X-ray transparency, non-magnetism, It can be suitably used as fiber-reinforced resin nuts and bolts for use in medical devices (fixators) that are fixed to the body.

10 Fiber-reinforced resin bolt 12 Core material 14 Fiber-reinforced material 16 Accordion-shaped fiber-reinforced material 20 Screw thread 22 Head portion 24 Threaded portion 26 Micro-diameter thread 28 Molded body 29 Resin-impregnated molded body 30 Metal mold 32 Made of fiber-reinforced resin nut

Claims (4)

A rod-shaped core material, around which a cylindrical fiber reinforced material is arranged with the core material as an inner axis, and then the fiber reinforced material is folded along the axial direction of the core material into a bellows shape. A fibrous material of the fiber reinforcement arranged in a plane perpendicular to the axial direction of the core material obtained by and a synthetic resin as a base material to be impregnated in the fibrous material, and further, The screw thread formed at a predetermined position is constituted by the structure of the fibrous material of the fiber reinforcement ,
By adjusting the folding width in the axial direction when the fiber reinforcing material is folded into a bellows shape along the axial direction of the core material to a predetermined interval, The height of the fibrous material is constantly changing,
The folding width is adjusted by adjusting the winding pitch of the micro-diameter thread spirally wound on the surface of the fiber reinforcement to a predetermined interval, and using each of the micro-diameter threads as a starting point, the fiber reinforcement A fiber-reinforced resin bolt characterized by being folded in a bellows shape in the axial direction of the core material . 2. The fiber-reinforced resin bolt according to claim 1, wherein said core material is a fiber-reinforced resin hollow rod or solid rod . A step of arranging a rod-shaped core material and a cylindrical fiber reinforcing material around it with the core material as an inner axis, and then folding the fiber reinforcing material into a bellows shape along the axial direction of the core material. Thus, a step of arranging the fiber in a plane perpendicular to the axial direction of the core material, a step of impregnating the fiber with a synthetic resin as a base material, and a step of impregnating the fiber with a screw thread in a predetermined range and forming
When the fiber reinforcing material is folded into a bellows shape along the axial direction of the core material, by adjusting the folding width in the axial direction to a predetermined interval, Constantly changing the height of the textile in
The folding width is adjusted by adjusting the winding pitch of the micro-diameter thread spirally wound on the surface of the fiber reinforcement to a predetermined interval, and starting from each of the micro-diameter threads, the fiber reinforcement A method for manufacturing a fiber-reinforced resin fastening member, characterized in that the material is folded in a bellows shape in the axial direction of the core material. 4. The method of manufacturing a fiber-reinforced resin fastening member according to claim 3, wherein the core material is a hollow rod or a solid rod made of fiber-reinforced resin.

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