JP4546653B2 - Manufacturing method of shaft - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method of manufacturing a shaft such as a golf shaft or a fishing rod, and more particularly to a method of manufacturing a shaft using an internal pressure molding method.
[0002]
[Prior art]
The shaft made of fiber reinforced resin using carbon fiber etc. is lightweight and has excellent torsional rigidity and bending rigidity, etc., and its usage has increased dramatically as a golf club shaft and fishing rod etc. Yes. Such a shaft has a multilayer structure composed of various layers having different fiber orientation directions, and the layer structure in the thickness direction of the shaft must be uniform along the circumferential direction. If the layer configuration is different in the circumferential direction of the shaft, non-uniform rigidity and uneven thickness will result in the circumferential direction of the shaft.
[0003]
There is an internal pressure molding method as one of the methods for manufacturing a shaft made of fiber reinforced resin as described above. In this method, a desired prepreg sheet is wound around a hollow mandrel having a fluid ejection hole on the surface via a stretchable tube, and the prepreg sheet is set in a molding die so that fluid flows from the fluid ejection hole of the mandrel. The prepreg sheet is injected into the mold and pressed against the inner wall of the molding die, and the shaft is molded by curing the resin of the prepreg sheet.
[0004]
In such an internal pressure molding method, when the prepreg sheet is pressed against the inner wall of the molding die, the prepreg sheet is wound around the mandrel so that the layer structure is uniform along the circumferential direction (hereinafter referred to as the mold standard). Called). That is, when the prepreg sheet is pressed against the inner wall of the molding die, the winding start end portion and the winding end end portion of the prepreg sheet are not matched in consideration that the winding of the wound prepreg sheet is released. Deliberately wrapping around an extra mandrel. For example, in the case of a layer that becomes three layers at the time of molding, adjustment is performed such that the prepreg sheet is wound around the mandrel three times and further wound around one third.
[0005]
[Problems to be solved by the invention]
However, in the internal pressure molding method, there is a problem that even if the prepreg sheet is wound with the above-described mold standard, the layer structure after molding is not uniform along the circumferential direction depending on the fiber orientation direction of the prepreg sheet. There was a difference in the bending rigidity of the shaft in the circumferential direction, or the shaft was warped (bent).
[0006]
The present invention has been made in view of such circumstances, and an object of the present invention is to provide a shaft manufacturing method that enables high-quality shaft manufacturing by an internal pressure molding method.
[0007]
[Means for Solving the Problems]
In order to achieve such an object, the present invention wraps a prepreg sheet on a mandrel via a stretchable tube, sets it in a molding die to make the inside of the tube airtight, and then the mandrel. In a method of manufacturing a shaft by an internal pressure molding method in which a fluid is supplied into the tube, the fluid is injected into the tube and the prepreg sheet is pressed against the inner wall of the molding die , and the resin of the prepreg sheet is thermally cured. The prepreg sheet in which the orientation direction of the fiber is 0 ° with respect to the central axis of the shaft, and the prepreg sheet in which the orientation direction of the fiber exceeds 25 ° with respect to the central axis of the shaft , The winding of the prepreg sheet whose orientation direction is 0 ° with respect to the central axis of the shaft is the winding start end and winding end There wound at least once to coincide, the orientation direction of the fibers is wound around the prepreg sheet in excess of 25 ° with respect to the central axis of the shaft 1 in the direction winding start than end winding end portion winding start It was set as the structure wound at least once so that it might overlap by the predetermined length selected from the range for / 10-10 / 10 circumference .
[0008]
As another aspect of the present invention, the prepreg sheet whose fiber orientation direction is 5 ° or less with respect to the central axis of the shaft is wound at least once so that the winding start end and the winding end end coincide with each other. It was set as the structure wound.
As another aspect of the present invention, the prepreg sheet whose fiber orientation direction is 10 ° or less with respect to the central axis of the shaft is wound at least once so that the winding start end and the winding end end coincide with each other. It was set as the structure wound.
As another aspect of the present invention, the prepreg sheet whose fiber orientation direction is 25 ° or less with respect to the center axis of the shaft is wound at least once so that the winding start end and the winding end end coincide with each other. It was set as the structure wound.
[0009]
As another aspect of the present invention, the winding start position of each prepreg sheet is configured to be distributed over the circumferential direction of the shaft.
Furthermore, as another aspect of the present invention, after the prepreg sheet is wound, the mandrel is pulled out from the tube, and then a molding mandrel having a length of 1/3 or less of the length of the shaft is inserted into the tube. After that, it is set in a molding die so that the inside of the tube is hermetically sealed, then a fluid is supplied into the molding mandrel and the fluid is injected into the tube to be molded and the resin of the prepreg sheet is thermoset. The configuration is such that
[0010]
DETAILED DESCRIPTION OF THE INVENTION
An embodiment of the present invention will be described.
The present invention has been made by paying attention to the fact that in the internal pressure molding method, the behavior when the prepreg sheet is pressed against the inner wall of the molding die differs depending on the fiber orientation direction. That is, the prepreg sheet in which the fiber orientation direction exceeds 25 ° with respect to the central axis of the shaft exhibits a behavior such as unwinding when pressed against the inner wall of the molding die. The prepreg sheet whose angle is 0 ° with respect to the central axis of the shaft is stretched by the stress when pressed against the inner wall of the molding die, and the winding state when wound around the mandrel is almost maintained. Is done. Therefore, in the present invention, the prepreg sheet whose fiber orientation direction is 0 ° with respect to the central axis of the shaft is wound at least once so that the winding start end portion and the winding end end portion coincide ( The winding direction of the prepreg sheet in which the fiber orientation direction exceeds 25 ° with respect to the central axis of the shaft is referred to as a mandrel reference). Wrap at least once (die standard) so as to overlap in the range of 1/10 to 9/10 rounds.
[0011]
In the present invention, as described above, the prepreg sheet in which the fiber orientation direction is 0 ° with respect to the central axis of the shaft is always wound on the mandrel basis, but the fiber orientation direction is within the range of 25 ° or less. The prepreg sheet having an angle with respect to can be determined based on the fiber material, the resin component, the diameter expansion ratio before and after molding, etc., whether to be wound on a mandrel basis or on a mold basis. In order to express the effects of the present invention more reliably, when a prepreg sheet whose fiber orientation direction is 5 ° or less with respect to the central axis of the shaft is wound on a mandrel basis, a prepreg sheet whose angle is 10 ° or less is also mandrel basis. Further, in the case of winding with a mandrel, a prepreg sheet of 25 ° or less may be wound. Therefore, for example, when a prepreg sheet whose fiber orientation direction is 10 ° or less with respect to the central axis of the shaft is wound on the mandrel basis, the fiber orientation direction is more than 10 ° and 25 ° or less with respect to the central axis of the shaft. The prepreg sheet is wound on a mold basis.
[0012]
FIG. 1 is a process diagram for explaining the shaft manufacturing method of the present invention. In the shaft manufacturing method of the present invention, first, the mandrel 1 is inserted into the stretchable tube 2 (FIG. 1 (A)), and the prepreg sheet 3 is wound around the mandrel 1 via the stretchable tube 2 (FIG. 1 ( B)).
Like the mandrel used in the conventional internal pressure molding method, the mandrel 1 functions to hold the tube 2 and has a hollow structure with a fluid ejection hole on the surface, and has a function of ejecting fluid in the molding die. Have. Such a mandrel 1 may be produced using any material such as metal or fiber reinforced plastic.
[0013]
The tube 2 having elasticity is, for example, latex, natural rubber, CR (polymer of chloroprene), SBR (copolymer of styrene and butadiene), NBR (copolymer of butadiene and acrylonitrile), IR (of isoprene). Polymers), diene synthetic rubbers such as copolymers of isobutylene and isoprene, EPM (copolymers of ethylene and propylene), EPDM (ternary copolymers of ethylene, propylene and a small amount of non-conjugated diene), A bag made of a material such as silicon rubber can be used.
[0014]
The prepreg sheet 3 to be used is obtained by impregnating a fiber with a curable resin, and the fiber is oriented at a desired angle (for example, 0 °, 90 °, 45 °, etc.) with respect to the central axis of the shaft to be manufactured. The plurality of types of prepreg sheets thus produced can be appropriately selected according to the characteristics required for the shaft to be produced. Examples of fibers constituting the prepreg sheet 3 include carbon fibers, polyamide fibers, boron fibers, metal fibers, glass fibers, and unidirectional fibers composed of two or more of these hybrid fibers, woven fabric fibers, braided fibers, and the like Can be used. As the resin, epoxy resin, melamine resin, phenol resin, thermoplastic nylon, polycarbonate resin, polyphenylene sulfide resin, polyether ether ketone resin, polyether imide resin, or the like can be used.
[0015]
In the present invention, the prepreg sheet whose fiber orientation direction is 0 ° with respect to the central axis of the shaft is always wound at least once so that the winding start end and the winding end end coincide with each other (mandrel reference), Further, for a prepreg sheet in which the fiber orientation direction exceeds 25 ° with respect to the central axis of the shaft, the winding end end is always at least once so as to overlap the winding start direction by a predetermined length from the winding start end. It is to be wound (on a mold basis). A prepreg sheet in which the fiber orientation direction has an angle of 25 ° or less with respect to the central axis of the shaft is based on the mandrel standard in consideration of the fiber material, the resin component, the diameter expansion rate before and after molding, and the like. It is determined whether to wrap around or on a mold basis.
[0016]
2 shows a prepreg sheet 3 having a fiber orientation direction of 0 ° with respect to the central axis of the shaft, and a prepreg sheet 12 having a fiber orientation direction of + 45 ° with respect to the central axis of the shaft. FIG. 3 is a cross-sectional view showing a state where a prepreg sheet 13 whose fiber orientation direction is −45 ° with respect to the central axis of the shaft is wound around the mandrel 1 via the stretchable tube 2. FIGS. 3 to 5 are views showing individual winding states of the prepreg sheets 11, 12, and 13 shown in FIG. 2, FIG. 3 is a prepreg sheet 11, FIG. 4 is a prepreg sheet 12, and FIG. A prepreg sheet 13 is shown. As shown in FIG. 2 and FIGS. 3 to 5, the prepreg sheet 11 in which the fiber orientation direction is 0 ° with respect to the central axis of the shaft starts to wind from the position of 0 ° in the circumferential direction, and is wound three times. The winding start end portion 11a and the winding end end portion 11b are wound so as to coincide with each other. Further, the prepreg sheet 12 in which the fiber orientation direction is + 45 ° with respect to the central axis of the shaft starts to wind from a position of 120 ° in the circumferential direction, winds twice, and further starts to wind (direction A in the figure). Wrapped so as to overlap with a predetermined length L1 in the direction). Furthermore, the prepreg sheet 13 in which the fiber orientation direction is −45 ° with respect to the central axis of the shaft starts to wind from a position in the circumferential direction of 240 °, winds twice, and then further starts the winding direction (arrow shown in the figure). A direction A) is wound so as to overlap with a predetermined length L2 (may be L1 = L2). Said length L1, L2 can be suitably set in the range for 1/10 to 9/10 round according to the prepreg sheet to be used.
[0017]
Next, the mandrel 1, the tube 2, and the prepreg sheet 3 are set in the molding die 21 (FIG. 1C). The molding die 21 includes a bowl-shaped cavity 22 having an opening at one end. For example, a positioning projection (not shown) is provided on the opening 22 a side of the cavity 22. In FIG. 1C, only the half of the molding die is shown for easy explanation.
[0018]
Next, a fluid is supplied into the mandrel 1, the fluid is injected into the tube 2 from a fluid injection hole (not shown), an internal pressure is applied to the prepreg sheet 3, the pressure is applied to the cavity 22 of the molding die 21, and heating is performed. Then, the prepreg sheet 3 is thermoformed. The fluid to be used includes air, nitrogen gas and the like, and can be appropriately selected according to the material of the prepreg sheet.
[0019]
In this thermoforming, the prepreg sheet 11 in which the fiber orientation direction is 0 ° with respect to the central axis of the shaft is stretched by the prepreg sheet itself due to the stress when pressed, and is almost wound around the mandrel. The winding start end portion 11a and the winding end end portion 11b remain matched. On the other hand, the prepreg sheet 12 in which the fiber orientation direction is + 45 ° with respect to the central axis of the shaft exhibits a behavior such as unwinding, and the length L1 shown in FIG. 4 does not overlap, and FIG. As shown, the winding start end 12a and the winding end 12b coincide. Similarly, the prepreg sheet 13 in which the fiber orientation direction is −45 ° with respect to the central axis of the shaft also exhibits a behavior such as unwinding, and the overlap of the length L2 shown in FIG. As shown in FIG. 7, the winding start end portion 13a and the winding end end portion 13b coincide with each other. Thereby, the layer structure after forming becomes uniform along the circumferential direction.
[0020]
Then, the shaft is obtained by pulling out the mandrel 1 and the stretchable tube 2.
The above-described shaft manufacturing method shows three types of prepreg sheets 11, 12, and 13 as the prepreg sheet 3 for ease of explanation, but it is needless to say that the present invention is not limited to this. In addition, the number of windings (number of layers) of each prepreg sheet is not limited. Furthermore, in the above-described example, the prepreg sheet 11 in which the fiber orientation direction is 0 ° with respect to the central axis of the shaft is positioned inside, and the fiber orientation direction is + 45 ° or −45 ° with respect to the shaft central axis. The prepreg sheets 12 and 13 are shown on the outer side, but the present invention is not limited to this, and the prepreg sheet of 0 ° orientation is located on the outer side or in the middle of the multilayer structure. Also good.
[0021]
Further, in the present invention, after the prepreg sheet 3 is wound, the mandrel 1 is pulled out from the tube 2, and instead, a molding mandrel having a length of 1/3 or less of the length of the shaft is inserted into the tube 2, Molding may be performed. By using such a molding mandrel, when it is inserted into the tube 2 and set in the molding die 21, bending due to its own weight is prevented, and the fluid hardly causes pressure loss. Since it is injected into the tube 2, the tube 2 can be uniformly expanded at a predetermined pressure.
[0022]
【Example】
Next, an Example is shown and this invention is demonstrated further in detail.
[Example]
A mandrel was inserted into a stretchable tube (made of latex material), and a prepreg sheet was wound around the tube. The prepreg sheet is a fiber-reinforced resin prepreg having a predetermined shape in which an epoxy resin is impregnated with carbon fibers oriented at 0 ° with respect to the central axis of the shaft (Q-U114 0800 manufactured by Toho Rayon Co., Ltd. (thickness: 0.10 mm)) ), And a fiber reinforced resin prepreg having a predetermined shape obtained by impregnating an epoxy resin with carbon fibers oriented at + 45 ° and −45 ° with respect to the central axis of the shaft (Q-A110-141 0800 manufactured by Toho Rayon Co., Ltd.) Three types having a thickness of 0.09 mm)) were used. Then, the prepreg sheet having 0 ° orientation was wound three times, and wound around the mandrel in a three-layer state so that the winding start end and the winding end end coincided (mandrel reference). Next, after winding the prepreg sheet with + 45 ° orientation at a position shifted by 120 ° in the circumferential direction from the winding start position of the prepreg sheet with 0 ° orientation, the prepreg sheet was wound twice, and then ½ lap Wrapped around the mandrel so that it only overlaps (die standard). Next, after winding the prepreg sheet having −45 ° orientation at a position shifted by 240 ° in the circumferential direction from the winding start position of the prepreg sheet having 0 ° orientation described above, winding the prepreg sheet twice, and then further halving Wrapped around the mandrel so that it only overlaps (die standard).
[0023]
Next, the mandrel was set in a molding die so that the axial direction of the mandrel was the horizontal direction. The molding die was composed of a pair of halves having a structure as shown in FIG. 1 (C) and capable of molding 6 shafts at the same time.
[0024]
Next, air is supplied from the fluid supply port of the mandrel into the mandrel, and air is injected from the fluid injection hole into the tube via the flow path to apply an internal pressure to the prepreg sheet and press-bond to the molding die, and 150 ° C. And the prepreg sheet was thermoformed. Then, the shaft (length 1205 mm) was obtained by drawing out the mandrel and the stretchable tube.
[0025]
The shaft manufactured in this manner was composed of three 0 ° oriented layers, two + 45 ° oriented layers and two −45 ° oriented layers, and a uniform thickness in the diameter direction of 0.55 mm. .
[0026]
Further, when the warpage of this shaft was measured by the following method, the blur width was 1.0 mm, and it was confirmed that there was no warpage.
(Measurement method of warpage)
The shaft is supported at two positions of 100 mm and 600 mm from the butt side end. In this state, the shaft is rotated around the axis, and the blur width at a position of 20 mm from the tip side end is measured. If the blur width is 1.5 mm or less, it is determined that there is no warp.
[0027]
[Comparative example]
A shaft was manufactured in the same manner as in the above example except that the prepreg sheet with 0 ° orientation was wound three times and then wound around a mandrel so as to overlap by 8/10 laps (die basis). .
[0028]
The shaft manufactured in this manner has two + 45 ° oriented layers and two −45 ° oriented layers, but there are four portions in the 0 ° oriented layer. It was 0.61 mm, which was thicker than other parts (thickness 0.55 mm). When such a shaft was measured for warpage in the same manner as in the example, the blur width was 4.5 mm, and warpage occurred.
[0029]
【The invention's effect】
As described in detail above, according to the present invention, the winding of the prepreg sheet on the mandrel via the stretchable tube is different depending on the difference in the orientation direction of the fiber, and is 0 ° with respect to the central axis of the shaft. The prepreg sheet is wound at least once so that the winding start end and the winding end end coincide with each other, and the prepreg sheet winding in which the fiber orientation direction exceeds 25 ° with respect to the central axis of the shaft Since the end end part is wound at least once so that it overlaps with the predetermined length in the winding start direction from the winding start end part, it is set in the molding die so that the inside of the tube is hermetically sealed and the fluid in the mandrel The prepreg sheet whose fiber orientation direction exceeds 25 ° with respect to the central axis of the shaft is unwound The prepreg sheet having a uniform thickness along the circumferential direction, showing the behavior and the like, and the fiber orientation direction being 0 ° with respect to the central axis of the shaft was stretched and wound around the mandrel. The state (uniform state along the circumferential direction) is almost maintained, and as a result, the layer structure after molding becomes uniform along the circumferential direction. As a result, the bending rigidity of the shaft is equal in the circumferential direction, and the shaft warps. A high-quality shaft without (bending) can be obtained.
[Brief description of the drawings]
FIG. 1 is a process diagram illustrating a shaft manufacturing method of the present invention.
FIG. 2 is a cross-sectional view showing a state in which a prepreg sheet is wound around a mandrel via a stretchable tube.
3 is a view showing a winding state of each prepreg sheet shown in FIG. 2. FIG.
4 is a view showing a winding state of each prepreg sheet shown in FIG. 2. FIG.
5 is a view showing a winding state of each prepreg sheet shown in FIG. 2. FIG.
FIG. 6 is a diagram showing a state in which the winding of the prepreg sheet in which the fiber orientation direction exceeds 25 ° with respect to the central axis of the shaft is unwound in thermoforming.
FIG. 7 is a view showing a state in which the winding of the prepreg sheet in which the fiber orientation direction exceeds 25 ° with respect to the central axis of the shaft is unwound in thermoforming.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Mandrel 2 ... Stretchable tube 3 ... Prepreg sheet 11 ... Prepreg sheet 12 which is oriented at 0 ° ... Prepreg sheet 13 which is oriented at + 45 ° ... Prepreg sheets 11a, 12a, 13a which are oriented at -45 ° ... 11b, 12b, 13b ... end of winding end 21 ... molding die

Claims (6)

After winding a prepreg sheet on a mandrel via a stretchable tube, it is set in a molding die to make the inside of the tube airtight, then a fluid is supplied into the mandrel and a fluid is injected into the tube In the method of manufacturing a shaft by an internal pressure molding method in which the prepreg sheet is molded by pressing the inner wall of the molding die and the resin of the prepreg sheet is thermally cured.
The method
When winding a prepreg sheet in which the orientation direction of the fiber is 0 ° with respect to the central axis of the shaft, and a prepreg sheet in which the orientation direction of the fiber exceeds 25 ° with respect to the central axis of the shaft, the orientation direction of the fiber is winding the prepreg sheet is 0 ° with respect to the central axis, wound at least once as winding start portion and the winding end portion coincides, the orientation direction of the fibers 25 ° with respect to the central axis of the shaft The prepreg sheet is wound at least once so that the winding end end overlaps with a predetermined length selected from the range of 1/10 to 9/10 rounds in the winding start direction from the winding start end. A method of manufacturing a shaft characterized by turning.   The winding of the prepreg sheet whose fiber orientation direction is 5 ° or less with respect to the central axis of the shaft is wound at least once so that the winding start end and the winding end end coincide with each other. The manufacturing method of the shaft as described in any one of.   The winding of the prepreg sheet whose fiber orientation direction is 10 ° or less with respect to the central axis of the shaft is wound at least once so that the winding start end and the winding end end coincide with each other. The manufacturing method of the shaft as described in any one of.   The winding of the prepreg sheet whose fiber orientation direction is 25 ° or less with respect to the central axis of the shaft is wound at least once so that the winding start end and the winding end end coincide with each other. The manufacturing method of the shaft as described in any one of.   The shaft manufacturing method according to any one of claims 1 to 4, wherein a winding start position of each prepreg sheet is dispersed over a circumferential direction of the shaft.   After winding the prepreg sheet, the mandrel is pulled out from the tube, and then a molding mandrel having a length of 1/3 or less of the length of the shaft is inserted into the tube, and then set in a molding die. The inside of the tube is hermetically sealed, and then a fluid is supplied into the molding mandrel and the fluid is injected into the tube to form the resin, and the resin of the prepreg sheet is thermally cured. The manufacturing method of the shaft in any one of Claims 5.

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