JP4327949B2 - Manufacturing method of shaft - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a mandrel used when a shaft such as a golf shaft or a fishing rod is manufactured by an internal pressure molding method, and a method of manufacturing a shaft using the mandrel.
[0002]
[Prior art]
Fiber reinforced resin shafts using carbon fibers, etc. are lightweight but have excellent torsional rigidity and bending rigidity, etc., and their use has increased dramatically as golf club shafts and fishing rods etc. Yes.
[0003]
One method for manufacturing such a shaft is an internal pressure molding method. 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 mold to allow fluid to flow from the fluid ejection hole of the mandrel into the tube. The shaft is molded by injecting and molding the resin of the prepreg sheet.
[0004]
[Problems to be solved by the invention]
However, the conventional mandrel used for the internal pressure molding method is longer than the length of the shaft to be manufactured and the internal flow path is narrow, so the pressure loss is large and it is difficult to instantaneously expand the entire tube with uniform pressure. This was a cause of molding defects.
[0005]
In addition, since the conventional mandrel is made of metal and is thin and long as described above, the mandrel is easily bent due to its own weight in the mold, and is formed when such bending occurs. There has been a problem that the thickness of the shaft becomes uneven in the diameter direction.
[0006]
Furthermore, since the conventional mandrel is long and heavy as described above, the workability is poor in the process of setting the mold and extracting the mandrel after molding. In particular, in the molding die in the internal pressure molding method, usually, a plurality of mandrels around which a prepreg is wound, for example, about 6 to 10 are placed and simultaneous molding is performed. It was.
[0007]
The present invention has been made in view of such circumstances, and a mandrel that enables the production of a high-quality shaft by an internal pressure molding method under good workability, and the mandrel can be used to easily increase the height. The object is to provide a method for producing a quality shaft.
[0008]
[Means for Solving the Problems]
  In order to achieve such an object, the present inventionThe shaft manufacturing method is to wind a prepreg sheet on a winding mandrel via a stretchable tube, then pull out the winding mandrel, and then provide a base at one end and tighten the tube at the other end. A tubular body having a portion, wherein the opening end of the base portion is a fluid supply port, and the opening end of the tube fastening portion is a fluid ejection hole, so that the base side of the mandrel is located outside The tube is inserted into the tube, then set in a mold, and the tube inner surface is crimped to the mandrel outer wall at the tube clamping portion of the mandrel to make the inside of the tube airtight, and then from the fluid supply port of the mandrel The fluid is supplied into the mandrel, the fluid is ejected from the fluid ejection hole into the tube, and the prepreg is formed. The over preparative resin is thermally curedThe configuration is as follows.
[0009]
  In addition, the present inventionManufacturing method of shaftIs provided with a ring-shaped rubber member on the outer wall portion of the tube clamping portionUse a mandrelThe configuration is as follows.
[0010]
  In addition, the present inventionManufacturing method of shaftIs provided with a positioning groove on the outer wall between the base and the tube clamping part.Use a mandrelThe configuration is as follows.
[0011]
  In addition, the present inventionManufacturing method of shaftThe cylindrical prepreg stabilizing member protrudes from the tube clamping portion, the opening end of the prepreg stabilizing member becomes the fluid injection hole, and the length of the prepreg stabilizing member is the length of the shaft to be manufactured. 1/3 or lessUse a mandrelThe configuration is as follows.
[0013]
In the present invention, since the mandrel is a cylindrical body composed of a base portion and a tube clamping portion, the mandrel is much shorter than the shaft to be manufactured, and the mandrel is attached to the tube instead of the winding mandrel. When inserted and set in the mold, the mandrel is prevented from bending, and the fluid supplied from the fluid supply port is injected into the tube from the fluid injection hole with almost no pressure loss, and the tube is predetermined. It can be uniformly expanded at a pressure of
[0014]
DETAILED DESCRIPTION OF THE INVENTION
An embodiment considered to be the best of the present invention will be described.
[0015]
Mandrel
1A and 1B are diagrams showing an embodiment of the mandrel of the present invention. FIG. 1A is a perspective view, and FIG. 1B is a cross-sectional view taken along the line I-I in FIG. In FIG. 1, a mandrel 1 is a cylindrical body that includes a base portion 2 and a tube clamping portion 3 and includes a flow path 4 therein. The open end of the base 2 is a fluid supply port 4 a that is one end of the flow path 4, and the open end of the tube tightening section 3 is a fluid ejection hole 4 b that is the other end of the flow path 4. In the illustrated example, a fluid supply cylinder C (shown by a two-dot chain line in FIG. 1B) is engaged with the fluid supply port 4a, and this fluid supply cylinder C is an external fluid supply device (not shown). It is connected to the. Further, a positioning groove 5 is formed between the base 2 and the tube tightening portion 3.
[0016]
The material of the mandrel 1 is not particularly limited, and a material that has rigidity and does not cause the mandrel 1 to bend, such as stainless steel, nickel-chromium plated iron, and carbon fiber reinforced plastic, is preferable.
[0017]
The dimensions of the base 2 and the tube clamping part 3 can be appropriately set according to the dimensions of the shaft to be manufactured. For example, the base 2 can be set in a range of an outer diameter of 10 to 50 mm and a length of 10 to 50 mm, and the outer shape is preferably a cylindrical shape. Further, the tube tightening portion 3 can be set in a range of an outer diameter of 10 to 50 mm and a length of 10 to 100 mm, and the outer shape may be either a cylindrical shape or a tapered shape with a narrow fluid ejection hole 4b side. The flow path 4 can be set with a diameter of about 2 to 10 mm, and the diameter of the fluid supply port 4a can be set as appropriate corresponding to the fluid supply cylinder C. The diameter of the fluid ejection hole 4b can be set in the range of 2 to 10 mm, and is usually the same as the diameter of the flow path 4.
[0018]
The positioning groove 5 is for determining the placement position of the mandrel when it is set in a mold in the shaft manufacturing method of the present invention described later. Therefore, the depth, width, etc. of the groove 5 are appropriately set according to the mold. In the mandrel of the present invention, the groove portion 5 may not be provided.
[0019]
2 is a view showing another embodiment of the mandrel of the present invention, FIG. 2 (A) is a perspective view, and FIG. 2 (B) is a cross-sectional view taken along line II-II in FIG. 2 (A). In FIG. 2, the mandrel 1 ′ has the same structure as the mandrel 1 described above except that a plurality of ring-shaped rubber members 6 are provided on the outer wall portion of the tube fastening portion 3, and the same member is the same member. Numbered. Further, the material of the mandrel 1 ′, the dimensions of each part, etc. are the same as those of the mandrel 1 described above, and the description thereof is omitted here.
[0020]
The tube tightening portion 3 of the mandrel 1 ′ has a ring-shaped recess 3 a formed on the outer wall portion with a predetermined interval along the axial direction, and the cross-sectional shape of the recess 3 a is a semicircle. A ring-shaped rubber member 6 having a circular cross-sectional shape is engaged with the recess 3 a, and about half of the rubber member 6 is configured to protrude from the outer wall surface of the tube fastening member 3. Such a rubber member 6 facilitates pressure bonding of the tube to the fastening member 3 and ensures airtightness in the tube when set in a mold in the shaft manufacturing method of the present invention described later. The thickness of the ring member 6 can be appropriately set within a range of 1 to 5 mm, and the dimension of the recess 3 a is set corresponding to the thickness of the ring member 6.
[0021]
The cross-sectional shape of the recess 3a may be a square, and the cross-sectional shape of the ring-shaped rubber member 6 may be a square.
[0022]
FIG. 3 is a view showing another embodiment of the mandrel of the present invention, FIG. 3 (A) is a perspective view, and FIG. 3 (B) is a cross-sectional view taken along line III-III in FIG. 3 (A). In FIG. 3, the mandrel 11 is a cylindrical body that includes a base portion 12, a tube fastening portion 13, and a prepreg stabilizing member 17, and includes a flow path 14 therein. The open end of the base 12 is a fluid supply port 14 a that is one end of the flow path 14, and the open end of the prepreg stabilizing member 17 is a fluid ejection hole 14 b that is the other end of the flow path 14. In the illustrated example, a fluid supply cylinder C (shown by a two-dot chain line in FIG. 3B) is engaged with the fluid supply port 14a, and this fluid supply cylinder C is an external fluid supply device (not shown). It is connected to the. Further, a positioning groove 15 is formed between the base 12 and the tube tightening portion 13.
[0023]
The material of the mandrel 11 is not particularly limited as in the case of the mandrel 1 described above, and has rigidity such as stainless steel, nickel-chromium plated iron, carbon fiber reinforced plastic, and the mandrel 11 is bent. Such materials are preferred.
[0024]
The dimensions of the base 12, the tube tightening part 13, and the prepreg stabilizing member 17 can be appropriately set according to the dimensions of the shaft to be manufactured. For example, the base 12 can be set in a range of an outer diameter of 10 to 50 mm and a length of 10 to 50 mm, and the outer shape is preferably a cylindrical shape.
[0025]
Further, the tube tightening portion 13 can be set in a range of an outer diameter of 10 to 50 mm and a length of 10 to 100 mm, and the outer shape may be either a cylindrical shape or a tapered shape with a narrow prepreg stabilizing member 17 side.
[0026]
Further, the prepreg stabilizing member 17 is a cylindrical body projecting from the tube tightening portion 13, and in the shaft manufacturing method of the present invention to be described later, bending or the like is caused during handling with the mandrel 11 inserted into the tube. It is for preventing and stabilizing the winding state of a prepreg sheet. The length L of the prepreg stabilizing member 17 is set to 1/3 or less of the length of the shaft to be manufactured. Therefore, for example, when manufacturing a shaft for a putter having a length of 35 inches (889 mm), the length L of the prepreg stabilizing member 17 is set to 296 mm or less, and for a driver having a length of 52 inches (1320.8 mm). In the case of manufacturing the shaft, the length L of the prepreg stabilizing member 17 is set to 440 mm or less. When the length L of the prepreg stabilizing member 17 is longer than 1/3 of the length of the shaft to be manufactured, in the shaft manufacturing method of the present invention described later, the mandrel is inserted into the tube, and the shaft after molding The workability of pulling out the mandrel from is lowered, which is not preferable. Further, when the material of the mandrel 1 is a material having a large specific gravity such as metal, the mandrel is easily bent by its own weight, and in the shaft manufacturing method of the present invention described later, the thickness in the diameter direction of the shaft may vary. is there. The outer diameter of the prepreg stabilizing member 17 can be set in a range of 10 to 50 mm, and the outer shape is preferably a tapered shape with a narrow side on the fluid ejection hole 14b side.
[0027]
The flow path 14 can be set with a diameter of about 2 to 10 mm, and the diameter of the fluid supply port 14a can be set as appropriate corresponding to the fluid supply cylinder C. The diameter of the fluid ejection hole 14b can be set in the range of 2 to 10 mm, and is usually the same as the diameter of the flow path 14.
[0028]
The positioning groove 15 is for determining the placement position of the mandrel when it is set in the mold in the shaft manufacturing method of the present invention described later. Therefore, the depth, width, and the like of the groove portion 15 are appropriately set according to the mold, and the groove portion 15 may not be provided.
[0029]
4 is a view showing another embodiment of the mandrel of the present invention, FIG. 4 (A) is a perspective view, and FIG. 4 (B) is a cross-sectional view taken along line IV-IV in FIG. 4 (A). In FIG. 4, the mandrel 11 ′ is the same as the mandrel 11 except that a plurality of ring-shaped rubber members 16 are provided on the outer wall portion of the tube fastening portion 13, and the same member number is assigned to the common member. It is attached.
[0030]
The tube tightening portion 13 of the mandrel 11 ′ is formed with a ring-shaped recess 13 a on the outer wall portion with a predetermined interval along the axial direction, and the cross-sectional shape of the recess 13 a is semicircular. A ring-shaped rubber member 16 having a circular cross section is engaged with the recess 13 a, and about half of the rubber member 16 is configured to protrude from the outer wall surface of the tube fastening member 13. Such a rubber member 16 facilitates pressure bonding of the tube to the fastening member 13 and ensures airtightness in the tube when set in a mold in the shaft manufacturing method of the present invention described later. The thickness of the ring member 16 can be set as appropriate within a range of 1 to 5 mm, and the dimension of the recess 13 a is set corresponding to the thickness of the ring member 16.
[0031]
The cross-sectional shape of the recess 13a may be a square, and the cross-sectional shape of the ring-shaped rubber member 16 may be a square.
[0032]
The material of the mandrel 11 ′, the dimensions of each part, and the like are the same as those of the mandrel 11 described above, and a description thereof is omitted here.
[0033]
Manufacturing method of shaft
Next, the manufacturing method of the shaft of this invention is demonstrated.
[0034]
FIG. 5 is a process diagram for explaining the shaft manufacturing method of the present invention using the mandrel 11 of the present invention. In the shaft manufacturing method of the present invention, first, the winding mandrel 21 is inserted into the stretchable tube 22 (FIG. 5A), and the prepreg sheet 23 is wound around the winding mandrel 21 via the stretchable tube 22. (FIG. 5B).
[0035]
The winding mandrel 21 preferably has a hollow structure in consideration of workability and has the function of holding the tube 22 as in the conventional mandrel used in the internal pressure molding method. However, since the winding mandrel 21 does not need a function of ejecting fluid in the mold, it is not necessary to provide a fluid ejection hole like the mandrel used in the conventional internal pressure molding method on the surface. Such a winding mandrel 21 may be made of any material such as metal or fiber reinforced plastic.
[0036]
The tube 22 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 (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.
[0037]
The prepreg sheet 23 to be used is obtained by impregnating fibers with a curable resin, and various prepreg sheets can be used according to the characteristics required for the shaft to be manufactured. Examples of the fibers constituting the prepreg sheet 23 include carbon fibers, polyamide fibers, boron fibers, metal fibers, glass fibers, 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. Further, a prepreg sheet 23 in which fibers are oriented at a desired angle (for example, 0 °, 90 °, 45 °, etc.) with respect to the central axis of the shaft to be manufactured can be used, and usually a plurality of types of prepreg sheets. Is used.
[0038]
Next, the winding mandrel 21 is pulled out from the tube 22 (FIG. 5C). Instead, the mandrel 11 of the present invention is inserted into the tube 22 from the prepreg stabilizing member 17 side, and the base 12 and the positioning groove portion are inserted. 15 is positioned outside the tube 22 (FIG. 5D). Since the mandrel 11 is a cylindrical body composed of the base 12, the tube fastening portion 13, and the prepreg stabilizing member 17, the mandrel 11 is significantly shorter than the shaft to be manufactured. Instead, the operation of inserting into the tube 22 is easy.
[0039]
Next, the mandrel 11, the tube 22, and the prepreg sheet 23 in the above state are set in a mold. FIG. 6 is a partial perspective view showing an example of a half of a mold used for the internal pressure molding method. In FIG. 6, the molding die 31 includes a bowl-shaped cavity 32 having an opening at one end, and a positioning projection 33 in the vicinity of the opening end side of the cavity 32. A tube fastening rubber member 34 is embedded in the vicinity of the inside of the convex portion 33. FIG. 7 is a perspective view of the rubber member 34 for tightening the tube. As shown in FIG. 7, the tube fastening rubber member 34 has a bowl-shaped groove portion 35 and a plurality of half ring-shaped convex portions 36 formed in the groove portion 35 so as to be orthogonal to the axial direction.
[0040]
FIG. 8 is a partial perspective view showing a state in which the mandrel 11, the tube 22, and the prepreg sheet 23 are placed on the half of the molding die 31 as described above, and FIG. It is a schematic sectional drawing which shows the state by which was closed. As shown in FIGS. 8 and 9, the mandrel 11 is set at a predetermined position by the positioning groove 15 being engaged with the positioning projection 33 of the mold 31, and the mandrel 11 tube The tightening portion 13 is at the position of the tube tightening rubber member 34 of the mold 31. Further, since the vicinity of the opening end of the tube 22 is at the position of the tube tightening portion 13 of the mandrel 11, the tube 22 is pressed against the tube tightening portion 13 of the mandrel 11 and the tube tightening rubber member 34 of the mold 31. ing. Thereby, the inner surface of the tube 22 is crimped | bonded to the outer wall of the mandrel 11, and the inside of the tube 22 is an airtight state.
[0041]
Next, the fluid is supplied into the mandrel 11 from the fluid supply port 14a of the mandrel 11, and the fluid is injected into the tube 22 from the fluid injection hole 14b via the flow path 14 to apply an internal pressure to the prepreg sheet to form a mold. The prepreg sheet is thermoformed by pressing and heating. 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. The mandrel 11 is significantly shorter than the shaft to be manufactured. Therefore, when the mandrel 11 is inserted into the tube 22 and set in the molding die 31, the mandrel 11 is prevented from being bent by its own weight, and the fluid supply port 14a. Since the fluid supplied from is injected into the tube 22 from the fluid injection hole 14b with almost no pressure loss, the tube 22 can be uniformly expanded at a predetermined pressure.
[0042]
Then, the shaft is obtained by pulling out the mandrel 11 and the stretchable tube 22.
[0043]
In addition, although the manufacturing method of the above-mentioned shaft is an example using the mandrel 11 of the present invention provided with the prepreg stabilizing member, the same applies even if the mandrel 1 of the present invention not including the prepreg stabilizing member is used. Thus, the shaft can be manufactured.
[0044]
Next, the manufacturing method of the shaft of the present invention using the mandrel 11 'of the present invention will be described.
[0045]
In the manufacturing method of the shaft using the mandrel 11 ′, the process up to the step of extracting the winding mandrel and inserting the mandrel 11 ′ into the tube 22 is the same as that using the mandrel 11 described above.
[0046]
FIG. 10 is a partial perspective view showing a state in which the mandrel 11 ′ is inserted into the tube 22 and the prepreg sheet 23 is placed on the half of the mold 31 ′. Since the mandrel 11 ′ is provided with a plurality of ring-shaped rubber members 16 at the tube tightening portion 13, the mold 31 ′ is not mounted with the above-described tube tightening rubber member 34, and continues to the cavity 32. A bowl-shaped cavity is formed up to the positioning convex portion 33. Except for this point, it has the same structure as that of the mold 31 described above.
[0047]
In FIG. 10, the mandrel 11 ′ is set at a predetermined position by engaging the positioning groove 15 with the positioning projection 33 of the molding die 31 ′. Since the vicinity of the opening end of the tube 22 is at the position of the tube tightening portion 13 of the mandrel 11 ′, the tube 22 is pressed against the tube tightening portion 13 of the mandrel 11 ′ and the cavity of the mold 31 ′. Thereby, the inner surface of the tube 22 is pressure-bonded to the outer wall of the mandrel 11 ′, and the inside of the tube 22 is in an airtight state.
[0048]
Next, the fluid is supplied into the mandrel 11 from the fluid supply port 14a of the mandrel 11 ', the fluid is injected into the tube 22 from the fluid injection hole 14b via the flow path 14, and an internal pressure is applied to the prepreg sheet to form the mold. The prepreg sheet is thermoformed by being pressed and heated. Thereafter, the mandrel 11 'and the stretchable tube 22 are pulled out to obtain a shaft.
[0049]
The shaft manufacturing method described above is an example using the mandrel 11 'of the present invention provided with the prepreg stabilizing member, but the mandrel 1' of the present invention not including the prepreg stabilizing member may be used. Similarly, the shaft can be manufactured.
[0050]
【Example】
Next, an Example is shown and this invention is demonstrated further in detail.
[0051]
[Example]
First, a mandrel of the present invention as shown in FIG.
(Mandrel specifications)
・ Outer diameter of base: 16.2mm
・ Base length: 34.5mm
・ Outer diameter of tube tightening part: 16.2mm
・ Length of tube tightening part: 70mm
-Groove depth: 3.1 mm
・ Width of groove: 15.7 mm
-Outer diameter of prepreg stabilizing member (tapered shape):
12.0 mm (tip side) to 16.2 mm (base side)
-Length of prepreg stabilizing member: 160mm
・ Flow path diameter (= diameter of fluid injection hole): 4.5 mm
-Diameter of fluid supply port: 11.5 mm
・ Material: Iron with nickel-chrome plating
[0052]
Next, a winding mandrel was inserted into an elastic tube (made of latex material), and a prepreg sheet was wound around the tube. The winding mandrel used was a tapered hollow body (outer diameter 4.0 mm (tip side) to 16.2 mm (butt side), length 1238 mm, material = spring steel SUP-9). The prepreg sheet includes a fiber reinforced resin prepreg having a predetermined shape obtained by impregnating an epoxy resin with carbon fibers oriented at 0 °, and a fiber having a predetermined shape obtained by impregnating an epoxy resin with carbon fibers oriented at ± 45 °. A reinforced resin prepreg (Q-U114-1100 (thickness: 0.124 mm) manufactured by Toho Rayon Co., Ltd.) was wound around a mandrel so as to have a layer structure of 5 layers each on the tip side and 2 layers each on the bat side. .
[0053]
Next, the winding mandrel was pulled out from the tube, and the mandrel was inserted into the tube so that the base portion and the positioning groove portion were located outside, and this was set in a mold. The molding die was composed of a pair of halves having a structure as shown in FIG. 6, and a mold capable of simultaneously molding six shafts with the mandrel axial direction as the horizontal direction was used.
[0054]
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 to press against the mold, and to 150 ° C. The prepreg sheet was thermoformed by heating. Then, the shaft was obtained by pulling out the mandrel and the elastic tube.
[0055]
The shaft thus produced had a uniform thickness in the diameter direction with a tip side of 2 mm and a butt side of 1 mm. Further, in the series of operations, mandrel insertion and extraction were easy.
[0056]
[Comparative example]
Instead of a winding mandrel, a conventional mandrel with a tapered structure and a fluid injection hole on the surface (outer diameter 4.0 mm (tip side) to 16.2 mm (butt side), length 1238 mm, material = nickel) -A prepreg sheet was wound through a tube in the same manner as in the example except that the chrome-plated iron material was used.
[0057]
Next, this is set in the mold used in the example, supplied into the mandrel from the fluid supply port of the mandrel, and air is injected into the tube from the fluid injection hole via the flow path to the prepreg sheet. A prepreg sheet was thermoformed by applying an internal pressure and press-bonding it to the mold and heating to 150 ° C. Then, the shaft was obtained by pulling out the mandrel and the elastic tube.
[0058]
The shaft manufactured in this manner has a uniform thickness of 1 mm in the diameter direction on the butt side, but the thickness in the diameter direction on the tip side varies in the range of 0.5 to 3.5 mm and is not uniform. It was something. Further, in a series of operations, handling workability such as mandrel conveyance and withdrawal was poor.
[0059]
【The invention's effect】
As described above in detail, according to the present invention, the mandrel is a cylindrical body in which the base portion is located at one end and the tube tightening portion is located at the other end, and the open end of the base is a fluid supply. It is assumed that the opening end of the tube tightening portion is a fluid injection hole, and even when a prepreg stabilizing member is projected, the length of the prepreg stabilizing member is 1 / of the length of the shaft to be manufactured. Since the length of the mandrel is 3 or less, the length of the mandrel is significantly shorter than that of the shaft to be manufactured. Therefore, when the mandrel is inserted into a tube instead of a winding mandrel and set in a mold, the mandrel is bent. The fluid supplied from the fluid supply port is jetted from the fluid jet hole into the tube with almost no pressure loss in the mandrel, and the tube is uniformly applied at a predetermined pressure. It can be expanded instantly, which makes it possible to produce a high-quality shaft with a uniform diametric wall thickness, as well as ease of insertion into the tube and extraction of the mandrel from the tube after molding. Is very effective.
[Brief description of the drawings]
1A and 1B are views showing an embodiment of a mandrel of the present invention, in which FIG. 1A is a perspective view and FIG. 1B is a cross-sectional view taken along the line I-I in FIG.
2 is a view showing another embodiment of the mandrel of the present invention, FIG. 2 (A) is a perspective view, and FIG. 2 (B) is a cross-sectional view taken along the line II-II in FIG. 2 (A). .
3 is a view showing another embodiment of the mandrel of the present invention, FIG. 3 (A) is a perspective view, and FIG. 3 (B) is a cross-sectional view taken along line III-III in FIG. 3 (A). .
4 is a view showing another embodiment of the mandrel of the present invention, FIG. 4 (A) is a perspective view, and FIG. 4 (B) is a sectional view taken along line IV-IV in FIG. 4 (A). .
FIG. 5 is a process diagram for explaining a manufacturing method of a shaft of the present invention using the mandrel of the present invention.
FIG. 6 is a partial perspective view showing an example of a half of a mold used for an internal pressure molding method.
FIG. 7 is a perspective view of a tube clamping rubber member mounted on a mold.
FIG. 8 is a partial perspective view showing a state where a mandrel, a tube, and a prepreg sheet are placed on a half of the mold.
FIG. 9 is a schematic cross-sectional view showing a state in which a pair of halves of the mold is closed.
FIG. 10 is a partial perspective view showing a state in which a mandrel, a tube, and a prepreg sheet are placed on the half of the mold.
[Explanation of symbols]
1, 1 ', 11, 11' ... Mandrel
2,12 ... Base
3, 13 ... Tightening part of tube
4, 14 ... flow path
4a, 14a ... Fluid supply port
4b, 14b ... Fluid injection holes
5, 15 ... Positioning groove
6,16 ... Ring-shaped rubber member
17 ... Prepreg stabilization member
21 ... Mandrel for winding
22 ... Elastic tube
23 ... Prepreg sheet
31 ... Mold

Claims (4)

After winding a prepreg sheet on a winding mandrel via a stretchable tube, the winding mandrel is pulled out, and then a cylindrical body having a base at one end and a tube clamping part at the other end. The opening end of the base portion is a fluid supply port, the opening end of the tube clamping portion is a fluid ejection hole, and a mandrel is inserted into the tube so that the base side of the mandrel is located outside, Thereafter, the tube is set in a mold, and the inner surface of the tube is crimped to the outer wall of the mandrel at the tube tightening portion of the mandrel to make the inside of the tube airtight, and then fluid is supplied into the mandrel from the fluid supply port of the mandrel. The fluid is injected from the fluid injection hole into the tube and molded, and the resin of the prepreg sheet is thermally cured. Method of manufacturing a shaft characterized in that. The method for manufacturing a shaft according to claim 1, wherein a mandrel having a ring-shaped rubber member provided on an outer wall portion of the tube tightening portion is used . The method for manufacturing a shaft according to claim 1 or 2, wherein a mandrel having a positioning groove portion provided in an outer wall portion between the base portion and the tube tightening portion is used . A tubular prepreg stabilizing member protrudes from the tube clamping portion, and the opening end of the prepreg stabilizing member becomes the fluid injection hole, and the length of the prepreg stabilizing member is 1 / length of the length of the shaft to be manufactured. The mandrel which is 3 or less is used, The manufacturing method of the shaft in any one of the Claims 1 thru | or 3 characterized by the above-mentioned .

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