JP2002233598A - Tubular body made of fiber reinforced resin - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a tubular body having a plurality of fiber reinforced prepreg sheets wound one on another, while reducing the rate of stress concentration at the winding starting ends or winding terminating ends of the prepreg sheets 12, 13, 14 and 16 or at their overlaps to improve the tubular body for resistance to the rupturing of reinforcing fibers at those portions. SOLUTION: The ends of the fiber reinforced prepreg sheets 12, 13, 14 and 16 are formed as inclined structures such that the end faces 4 of the sheets are single-sided sloping faces each of which is thinner on the inside. A resin pool containing no reinforcing fibers does not exist at the portions of the inclined structures and the reinforcing fibers of the fiber reinforced prepreg sheets are distributed over the entire sloping faces. The amount by which a resin impregnates the single-sided sloping face part of each prepreg sheet is desirably from 10 to 36 wt.%, and the angle of the single-sided sloping face with an inside surface is preferably 70 to 20 deg.. The tubular body, even with a stack of prepreg sheets using reinforcing fibers with a tensile elasticity of 400 to 1,000 GPa, can prevent rupturing of the reinforcing fibers due to stress concentration.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tubular body formed by winding a plurality of fiber reinforced prepreg sheets and laminating the prepreg sheet at the beginning and end of the wrapping, or at the spliced portion. To improve the generation of wrinkles and the breakage of reinforcing fibers.

[0002]

2. Description of the Related Art A tubular body such as a shaft of a golf club, a fishing rod, a handle of sports equipment, etc. is made of a fiber-reinforced prepreg as shown in FIG. The sheets 3 are laminated by winding them around a plurality of metal cores by a sheet wind method, and after a heat shrink tape is wound around the outer periphery thereof, a heat-curing treatment is performed to melt the fiber reinforced prepreg sheets 3 mutually. It is generally made of a fiber-reinforced resin that has been heat-shrinked to remove the heat-shrinkable tape and the core metal. Here, a thermosetting resin such as an epoxy resin, a phenol resin, or an unsaturated polyester resin is used as the resin 1 depending on the purpose, and a carbon fiber, a glass fiber, a boron fiber, an aramid as the reinforcing fiber 2 is used. While long fibers of the high strength fiber and high elastic fiber is used, such as fibers, fiber-reinforced Puripuregushi use in the manufacture of the tubular body - DOO 3 differs by the shape and length of the tubular body, for example, the tubular body When the thickness at the distal end side is reduced, a short one is mixed and wound around only the base side so that the number of windings at the distal end side is reduced. Further, when the length of the tubular body is extremely long, it is difficult to smoothly wind the entire length with one long fiber reinforced prepreg sheet 3. The front and rear ends are joined by overlapping.

However, these fiber-reinforced prepregs
When the sheet 3 was wound and laminated, the fiber-reinforced prepreg sheet 3 was obtained by cutting the raw material in the thickness direction, and the end face 4 was perpendicular to the front face 5 and the back face 6 as shown in FIG. As a result, a step 7 is formed at the start and end ends of the winding in the width direction as shown in FIG. Also, as shown in FIG. 9, a step 7 is formed in the overlapping portion in the length direction, and that portion becomes a gap. For this reason,
The strength rapidly changes before and after the step 7, and the rigidity distribution and the strength distribution in the outer peripheral direction and the length direction become non-uniform, and the durability is reduced. In particular, when the fiber-reinforced prepreg sheet 3 is made of a high-elastic fiber having an elastic modulus of 400 to 1000 GPa as the reinforcing fiber 2, when the reinforcing fiber 2 is a carbon fiber, brittle fracture is likely to occur. If there is a step 7 in the portion, the fiber reinforced prepreg sheet 3 wound around the outside thereof is pressed against the void portion of the step 7 when the heat shrink tape is wound, causing wrinkles and bending, and fiber breakage. Cause

Therefore, various methods have been proposed for preventing a step from being generated in the winding of the fiber reinforced prepreg sheet 3. For example, (1) a method in which the width of the fiber reinforced prepreg sheet 3 is wound once so that both ends abut each other so that only one layer is formed by one sheet, and (2) fiber reinforced. A method of reducing the thickness of the prepreg sheet 3, (3) a method of defining a winding start position of the fiber-reinforced prepreg sheet, and dispersing a plurality of steps in an outer peripheral direction (Japanese Patent Application Laid-Open No. 10-151690). (4) The fiber reinforced prepreg sheet 3 is made to have a width of one turn, and the both end portions are made thin so as to form an inclined portion in which the end surfaces are opposite to each other, and only the inclined portion is turned by one turn. A method of superimposing each time like a butt (Japanese Unexamined Patent Publication No.
0-291265).

However, in the method (1), it is extremely difficult to accurately match the fiber-reinforced prepreg sheets 3 having different widths for each layer, and the layers are usually disturbed by an external pressure applied during heat curing. , Wrinkles occur.
In addition, the method (2) increases the number of windings and lowers the work efficiency, and the method (3) does not eliminate the step. Further, in the method (4), a prepreg sheet having a width corresponding to the outer periphery thereof must be prepared in accordance with a tubular body that becomes thicker each time it is wound, and the prepreg sheets must be wound sequentially, which makes the operation complicated. , Work efficiency is low. Further, in this method, the inclined surface is formed by hot pressing, but the fiber reinforced prepreg sheet 3 has a resin impregnation amount of 36 watts.
If it is less than t%, there is a gap between the reinforcing fibers 2 that is not filled with the resin 1, and the gap increases with a decrease in the impregnation amount. If it is attempted to form a slope with a thinner side, even if the resin 1 is fluidized by hot pressing, the resin 1 will be absorbed into the lower gap, so that the slope cannot be formed. On the other hand, in the case of the fiber reinforced prepreg sheet 3 having a resin impregnation amount of more than 36 wt%, if an inclined surface is formed at the end by hot pressing, as shown in FIG. And it protrudes into a thin shape on the lower side,
Since the resin pool R does not contain the reinforcing fiber 2, the reinforcing fiber 2 does not exist on the entire end face. If the reinforcing fiber 2 does not exist on the entire end face, the thin resin reservoir R has a low rigidity and a small force for holding down the sheet inside the resin reservoir R. Therefore, the tightening when the heat shrink tape is wound around the outermost layer. As a result, it is not possible to prevent the inner sheet from rising due to the above-mentioned problem, and the inner sheet has wavy wrinkles and fiber breakage. In the case of the fiber reinforced prepreg sheet 3 in which the step 7 caused by winding and the resin impregnation amount is more than 36 wt%, the gap is not filled by winding the heat shrink tape, but it is fluidized in the subsequent heat hardening process. The filled resin 1 flows and is buried, but the reinforcing fibers 2 do not move to this resin portion. This is because the reinforcing fiber 2 is a long fiber and its movement is restricted, so that the movement is only a little disturbed in the orientation and is difficult to move.

[0006]

SUMMARY OF THE INVENTION The present invention provides a fiber reinforced resin tubular body formed by winding a plurality of fiber reinforced prepreg sheets and laminating the same. is there.

[0007]

According to the present invention, there is provided a tubular body made of a fiber-reinforced resin, wherein at least one of the fiber-reinforced prepreg sheets has at least one end in a tubular body laminated by winding a plurality of the fiber-reinforced prepreg sheets. The end portion has an inclined structure having a thin sloping surface on the inner side, and the sloping portion has no resin pool containing reinforcing fibers, and the entire sloping surface has a fiber-reinforced prepreg material.
It is characterized by the fact that the reinforcing fibers are distributed. Here, it is preferable that the resin impregnation amount of the one slope portion of the fiber reinforced prepreg sheet is 10 to 36% by weight, and the angle of the one slope surface with respect to the inner side surface is preferably 70 to 20 °. Further, the tubular body has a tensile modulus of 400 to 1000 G.
At least one prepreg sheet using a reinforcing fiber of Pa may be laminated.

[0008]

FIG. 1 shows a golf club shaft 8 as a tubular body according to the present invention. As shown in FIG. 2, the shaft 8 is formed by winding a fiber reinforced prepreg sheet shown in FIG. 3 around a mandrel 11 having a circular cross section which gradually becomes tapered from the base 9 to the tip 10. It is manufactured and the winding method is the same as that of the conventional prepreg sheet 3 shown in FIG. That is, the winding is performed at the tip 1 of the mandrel 11.
First, the prepreg sheet 12 for reinforcing the front end part is partially wound, and then the first main prepreg sheet 13 and the second main prepreg sheet 14 are spirally wound around the entire length three times, respectively. The base-side reinforcing prepreg sheet 15 is partially wound around the base 9, and finally, the third main prepreg sheet 16 is wound around the entire length, heat-cured, and the mandrel 11 is pulled out. In the heat curing treatment, the third main prepreg sheet 1 is usually used before the treatment.
The entire outer periphery of 6 is pressed and covered with a heat-shrink tape, the heat-shrink tape is shrunk at the time of heat curing, and each prepreg sheet is further pressed by the shrink force to bring the prepreg sheets into close contact with each other and heated in that state. In this way, welding is integrated. The heat shrink tape is peeled off before polishing the outer periphery.

Here, a prepreg sheet 1 for reinforcing the tip portion
2 has a right-angled triangle, and is wound so that a right side 12a is parallel to the axis of the mandrel 11, but the prepreg sheets 13 to 16 other than the prepreg sheet 12 for reinforcing the distal end portion are Each of the shapes is an isosceles trapezoid, and is wound so that the base is on the base 9 side of the mandrel 11. These prepreg sheets 1
2 to 16 oblique sides 12a, 12b, 13a, 13b, 14
4A, 14B, 15A, 15B, 16A, and 16B, the end face 4 has a front surface 5 or a back surface 6 as shown in FIG.
In contrast, the rear surface 6 has an inclined structure in which the side of the back 6 has a slope that is thinner.
Are distributed over the entire surface in an exposed state, and the inclined structure portion has the same structure as the central portion, and there is no resin pool R containing the reinforcing fibers 2 there. Similarly, the upper side 15c of the base-side reinforcing prepreg sheet 15 also has an inclined end portion, and the end surface 4 has a single-slope surface with a thinner rear surface. It is desirable that the angle [theta] of the one sloping surface of each of the prepreg sheets with respect to the front surface 5 or the back surface 6 is 70 [deg.] To 20 [deg.]. If it is larger than 70 °, the step becomes large, and if it is smaller than 20 °, the tip becomes sharp and handling becomes dangerous. Also, if it is bent or wound by a slight contact, a large step may be generated.

In this shaft 8, the oblique sides 12a and 12b of the prepreg sheet 12 for reinforcing the distal end portion and the end faces 4 of the oblique sides 13a and 13b of the first main prepreg sheet 13 have thinner inclined surfaces on the inner side. Therefore, as shown in FIG. 5, the thickness in the outer peripheral direction gradually increases at the winding start portion, and conversely, the thickness gradually decreases at the winding end portion, so that no step occurs. In addition, the reinforcing fibers 2 are distributed over the entire surface on one side of the end, and the inclined structure has the same structure as the central part. Then it gradually decreases. As a result, the concentration of stress is reduced at the winding start portion and the winding end portion. Also, since the inclined structure portion on one slope is held down by the prepreg sheet wound outside, even if the prepreg sheet is tightly wound when winding the heat shrink sheet, it is wound inside. No wrinkles or breakage of the reinforcing fibers occur in the prepreg sheet. The same applies to the winding start portion and the winding end portion of the second main prepreg sheet 14, the base side reinforcing prepreg sheet 15 and the third main prepreg sheet 16.
Also, the upper side 15c of the base-side reinforcing prepreg sheet 15
As shown in FIG. 6, the thickness of the wound portion gradually increases and decreases in the axial direction of the mandrel 11 because the end face 4 has an inclined structure in which the end face 4 is a thin slope on the inner side. However, the amount of reinforcing fibers also increases and decreases. For this reason, the concentration of stress on the winding start portion in the axial direction also becomes smaller,
In addition, wrinkles and fiber breakage due to tight tightening are also prevented.

[0013] The stress dispersion and the prevention of the reinforcing fiber breakage by the end portion having a single inclined surface with the end surface 4 having the reinforcing fibers 2 distributed over the entire surface can be achieved by using such an inclined structure even at one end. If this is the case, it is effective at that part, so this may be applied to a part that requires stress dispersion or the like, and it is not necessary to make all the ends have an inclined structure. Also, it is not necessary that all the wound prepreg sheets have an inclined structure. If at least one of the wound prepreg sheets has an inclined structure, stress dispersion and prevention of reinforcing fiber breakage can be achieved. it can. In order to make the end of the prepreg sheet a single slope with the end face 4 distributed over the entire surface of the reinforcing fiber 2 and the inclined structure portion of the single slope without a resin pool containing the reinforcing fiber, the end face 4 should be vertically aligned. The table, which is usually arranged horizontally with respect to the cutting blade moving up and down, is inclined in the plane direction of the cutting blade,
A method of cutting the raw material of the prepreg sheet, a method of cutting the raw material in that state by inclining the surface direction of a knife such as a knife at an acute angle with respect to the prepreg sheet, or the like may be used.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The diameter of a tapered taper from the base to the tip is reduced, and a prepreg screen is formed on a mandrel having a base diameter of 14.5 mm, a tip diameter of 5.5 mm and a length of 1500 mm in the same configuration and order as in FIG. After winding the sheets 12 to 16, shafts of various golf clubs were manufactured by a method of performing a heat curing treatment. The prepreg sheets 12 to 16 of the shafts are oblique sides 12a, 12b, 13a, 13b, 14a, 14b, 1
The end portions of 5a, 15b, 16a, 16b and the upper side 15c are inclined structures whose end faces are θ = 60 ° with respect to the surface 5 (in the fourth embodiment, the end faces of the oblique sides 12a, 12b, 15a and 15b are θ = 45 °). , The end surface of the upper side 15c is inclined at θ = 45 °), and winding is performed so that the thinner part of the inclined structure is on the inner side. At the time of winding, the prepreg sheet 12 for reinforcing the distal end, the prepreg sheet 15 for reinforcing the base side, and the third main prepreg sheet 16 are the same for each shaft, and the first main prepreg sheet 13 and The second main prepreg sheet 14 was changed, and the winding angle of the reinforcing fiber 2 around the axis of the mandrel 11 was also changed.

[0013]

Comparative Example Prepreg sheets 12-1 in Examples 1-4
6 to the hypotenuses 12a, 12b, 13a, 13b, 14a, 1
4b, 15a, 15b, 16a, 16b and upper side 15
The end of c was changed so that the end face 4 was θ = 90 ° with respect to the surface. The prepreg sheets 12 and 15 had the resin impregnation amount changed to 40 wt%, and the hypotenuses 12a, 12b, 15
a, 15b and a press surface at the end of the upper side 15c.
A thin resin pool corresponding to about 30% of the thickness of the prepreg sheet was formed below the end face by applying a hot press inclined to 60 °. Table 1 shows prepregs used for each shaft in Examples and Comparative Examples. Table 2
FIG. 1 shows the observation results of the lamination state in the cross section taken along the line AA and the cross section taken along the line BB in FIG.

[0014]

[Table 1] (Note) X of the end face angle is a thin resin pool formed under the end face by hot pressing.

[0015]

[Table 2]

[0016]

As described above, fiber-reinforced prepregs
In a tubular body laminated by winding a plurality of sheets, at least one of the fiber reinforced prepreg sheets has an inclined structure in which at least one end is a thin inclined surface with the end face being inward. There is no resin pool on the inclined structure, and fiber reinforced prepreg
When the reinforcing fibers of the preform are distributed, the change in the thickness of the prepreg sheet at the winding start portion and the end portion of the prepreg sheet whose end surface is incline becomes gentle, and the change in the amount of the reinforcing fiber. Also moderates, disperses the stress applied to those parts, and the gap formed by the lower layer and the upper layer at the winding start part and the end part becomes smaller, and the deformation of the lower layer and the upper layer decreases Therefore, the reinforcing fibers are less likely to break. For this reason, a plurality of prepreg sheets can be wound without reducing the thickness, and the winding operation is simple and the work efficiency is high.
In particular, even if the resin impregnation amount of the one side of the fiber reinforced prepreg sheet is 10 to 36 wt%, the one side of the slope can have the reinforcing fibers distributed over the entire surface. The fiber-reinforced Puripuregushi - the City of reinforcing fibers angle with respect to the inner surface of the distribution piece slopes there ° 70 to 20, the reinforcing fiber is less likely to break. The tubular body has a tensile modulus of 400 to 1000 GP
Even when at least one prepreg sheet using the reinforcing fiber (a) is laminated, breakage of the reinforcing fiber can be prevented.

[Brief description of the drawings]

FIG. 1 is a perspective view of a shaft of a golf club which is a fiber-reinforced resin tubular body of the present invention.

FIG. 2 illustrates a mandrel used to manufacture the shaft of the golf club of FIG.

3 is a plan view of a prepreg sheet used when manufacturing the shaft of the golf club of FIG. 1 using the mandrel of FIG. 2;

4 is a cross-sectional view of the prepreg sheet of FIG. 3 from which an intermediate portion is omitted.

FIG. 5 is a sectional view taken along line AA of FIG. 1;

FIG. 6 is a sectional view taken along line BB of FIG. 1;

FIG. 7 is a cross-sectional view of a conventional prepreg sheet, in which an intermediate portion is omitted.

FIG. 8 is a cross-sectional view of a shaft of a conventional golf club.

FIG. 9 is a partial longitudinal sectional view of a shaft of a conventional golf club.

FIG. 10 is a cross-sectional view in a case where an end portion of a prepreg sheet is subjected to hot pressing to form a one-sided slope.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Resin 2 Reinforcing fiber 3 Fiber reinforced prepreg sheet 4 End face 5 Front surface 6 Back surface 7 Step 8 Golf club shaft 9 Base 10 Tip 11 Mandrel 12 Tip prepreg sheet 12a Right side 12b Oblique side 13 First main Prepreg sheet 13a, 13b Oblique side 14 Second main prepreg sheet 14a, 14b Oblique side 15 Base-side reinforcing prepreg sheet 15a, 15b Oblique side 15c Upper side 16 Third main prepreg sheet 16a, 16b Oblique side R Resin pool

Claims (4)

[Claims] In a tubular body laminated by winding a plurality of fiber-reinforced prepreg sheets, at least one of the fiber-reinforced prepreg sheets has a slope having at least one end and a thin inclined surface with an end face inward. Fiber reinforced resin characterized in that there is no resin pool containing reinforcing fibers in the inclined structure portion, and fiber reinforced prepreg sheet reinforcing fibers are distributed over the entire slope. Tubular body. 2. The fiber-reinforced resin tubular body according to claim 1, wherein the resin-impregnated amount on one slope of the fiber-reinforced prepreg sheet is 10 to 36 wt%. 3. The angle of the one inclined surface to the inner surface is 70 to
The fiber-reinforced resin tubular body according to claim 1, wherein the angle is 20 °. 4. The tubular body has a tensile modulus of 400 to 1000.
2. A prepreg sheet comprising GPa reinforced fibers, wherein at least one prepreg sheet is laminated.
The tubular body made of a fiber reinforced resin according to the above.