JP2005168786A - Golf club shaft and golf club - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a golf club shaft and a golf club which have a strength sufficient against the deflection of the golf club shaft while maintaining a hitting touch satisfying the golfers sufficiently in the golf club shaft constructed using a metal foil and a fiber-reinforced resin material. <P>SOLUTION: Metal film layers 24 and 28 of the golf club shaft 12 are formed by getting a rolled metal foil wound properly and the metal foil is positioned within the range of 60°-120°in the direction of rolling thereof along the length of the golf club shaft. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a golf club shaft configured by laminating a fiber reinforced resin material and a metal film layer, and a golf club using the golf club shaft.

  Conventionally, there are golf club shafts made of a single metal such as a steel golf club shaft and those made of a fiber reinforced resin (FRP) material such as a carbon fiber reinforced resin (CFRP) material.

In general, a golf club using a golf club shaft made of a single metal such as a steel golf club shaft is more metal than a golf club using a golf club shaft made of a fiber reinforced resin (FRP) material. Under the influence of the physical properties of the single body, the damping of the impact vibration upon hitting the golf ball is small, and the hit feeling is not preferable for the golfer.
On the other hand, a golf club using a golf club shaft made of FRP material is affected by the damping characteristics of the reinforcing fiber, and therefore, compared with a golf club using a golf club shaft made of a single metal, The damping of the hit vibration at the time of hitting was extremely large, and the hit feeling was not preferable for the golfer. That is, a golf club shaft that provides a hit feeling that golfers like has not been offered to the market.

On the other hand, the following Patent Document 1 discloses a golf club shaft constituted by at least two fiber-reinforced composite resin layers and a composite layer in which metal foil layers are laminated.
Patent Document 2 below discloses a golf club shaft in which a fiber reinforced resin layer is formed on the inner peripheral surface of a metal pipe.

  However, golf clubs using these golf club shafts still have a satisfactory feel to the golfer and do not have sufficient strength against the deflection of the golf club shaft.

JP-A-5-49719 JP 2002-126142 A

  Therefore, in order to solve the above-mentioned problems, the present invention provides a golf club shaft constituted by using a metal foil and a fiber reinforced resin material, which is sufficient for the golf club shaft to bend while maintaining the hit feeling felt by the golfer. An object of the present invention is to provide a golf club shaft having strength and to provide a golf club using the golf club shaft.

  In order to achieve the above object, the present invention provides a golf club shaft configured by laminating a fiber reinforced resin layer and a metal film layer, and the metal film layer is formed by winding a rolled metal foil. The golf club shaft is characterized in that the rolling direction of the metal foil is set in the range of 60 to 120 degrees with respect to the longitudinal direction of the golf club shaft.

Here, the metal film layer is formed in a plurality of layers, and the rolling direction of the metal foil is set in a range of 60 to 120 degrees with respect to the longitudinal direction of the golf club shaft in at least one of the plurality of layers. Is preferred.
Further, a plurality of the metal film layers are formed, and these layers have tensile strength along the longitudinal direction of the golf club shaft (tensile in a direction having an inclination angle of 0 degrees with respect to the longitudinal direction of the golf club shaft). Metal foils of metal materials having different strengths are used, and it is preferable that the metal material having a high tensile strength is used on the outer layer side.
The difference in the tensile strength of the metal material means that the tensile strength of the larger one of the tensile strength values is 3% or more based on the smaller tensile strength to be compared.
The metal film layers are formed in a plurality of layers. In these layers, the tensile strength along the longitudinal direction of the golf club shaft increases stepwise toward the outer layer, and the metal materials having different tensile strengths. Or it is preferable that the metal foil which consists of a metal material from which a kind differs is used.
Here, the type of metal material is different in the case of a single metal, it is a metal of a different type, and in the case of an alloy, the smaller value of the composition ratio of elements common to the alloy to be compared. The value when taking out and totaling is less than 30%. For example, 6-4 titanium alloy (Ti: Al: V = 90: 6: 4) and 15-5-3 titanium alloy (Ti: Mo: Zr: Al = 77: 15: 5: 3, Ti-15Mo— 5Zr-3Al titanium alloy), the total value is 80% (= 77 + 3), so the 6-4 titanium alloy and the 15-5-3 titanium alloy are not different metal materials. .
The metal film layer has a thickness of, for example, 0.005 mm or more and 0.2 mm or less, and the thickness is preferably greater than 0.1 mm and less than 0.2 mm.

Moreover, the metal foil of the said metal film layer uses the metal material whose specific gravity is 8.5 or less, for example.
Furthermore, the metal foil is a long foil whose rolling direction is set in a range of 60 to 120 degrees with respect to the longitudinal direction of the golf club shaft, and the metal film layer is formed in the longitudinal direction of the metal foil. Is formed by winding this metal foil, for example, by 50 mm or more along the longitudinal direction of the golf club shaft. Furthermore, in the golf club shaft, the ratio of the total mass of the metal thin film layer to the mass of the golf club shaft is preferably 0.08 or more.

Further, the fiber reinforced resin layer is formed as a plurality of layers at least partially as a fiber reinforced layer within a range of an inclination angle of ± 30 degrees with respect to the longitudinal direction of the golf club shaft. It is preferable to use reinforcing fibers having different tensile strengths or different types of reinforcing fibers in which the tensile strength of the reinforcing fibers along the orientation direction of the reinforcing fibers increases stepwise toward the outer layer.
Here, the type of the reinforcing fiber is different from the value of the tensile elastic modulus (Young's modulus) of the reinforcing fiber along the direction of the reinforcing fiber, the larger one based on the tensile elastic modulus of the smaller reinforcing fiber to be compared This means that the tensile elastic modulus of the reinforcing fiber is larger by 10% or more. Further, the reinforcing fiber having different tensile strength means that the tensile strength of the larger reinforcing fiber is 3% or more based on the tensile strength of the smaller reinforcing fiber to be compared among the tensile strength values along the direction of the reinforcing fiber. It means big.

In addition, the ratio of the mass of the golf club shaft to the length of the golf club shaft is preferably 0.1 g / mm or less.
The metal film layer is preferably one in which a resin film is provided between the metal film layer and the fiber reinforced resin layer and bonded to the fiber reinforced resin layer. In that case, the said resin film is 0.02-0.2 mm in thickness, for example, It is a film containing the support body which consists of any one fiber of glass fiber, carbon fiber, and a synthetic fiber.
Further, the metal film layer of the golf club shaft is formed of a metal foil, and after applying a room temperature curable adhesive to the surface of the metal foil, a fiber reinforced resin material to be the fiber reinforced resin layer is applied to the coated surface. The adhesive may be provided and cured at room temperature, and then heated at the curing temperature of the fiber reinforced resin material to form the fiber reinforced resin layer.

  In the golf club shaft, the reinforcing fiber in the fiber reinforced resin layer has physical properties of a tensile strength in the orientation direction of the reinforcing fiber of 2500 MPa or more and a specific gravity of 2.6 or less, and the metal foil in the metal film layer is The tensile strength is preferably 300 MPa or more and the specific gravity is preferably 1.8 or more.

  The present invention also provides a golf club characterized in that a grip portion is provided at one end of the golf club shaft and a golf club head is provided at the other end.

The golf club shaft of the present invention is formed by laminating a metal film layer formed by winding a fiber reinforced resin layer and a rolled metal foil, and the rolling direction of the metal foil is the longitudinal direction of the golf club shaft. The metal foil is arranged so as to coincide with a direction substantially perpendicular to the direction. For this reason, the tensile strength of the metal film layer along the direction orthogonal to the rolling direction of the metal foil, that is, the longitudinal direction of the golf club shaft is larger than the tensile strength in the direction orthogonal to the longitudinal direction. The strength against bending can be effectively improved.
Furthermore, metal foils made of metal materials having different tensile strengths are used for the plurality of metal layers formed of the metal foil, and the tensile strength along the longitudinal direction of the golf club shaft increases stepwise toward the outer layer. Yes. That is, since the metal material having a higher tensile strength is used as it is farther from the central axis of the golf club shaft, the strength against bending (bending deformation) of the golf club shaft can be improved efficiently.

  Hereinafter, a golf club shaft and a golf club of the present invention will be described in detail based on preferred embodiments shown in the accompanying drawings.

  FIG. 1 is a perspective view showing an example of a golf club of the present invention using the golf club shaft of the present invention. FIG. 2 is a cross-sectional view taken along the line A-A ′ in FIG. 1 showing the configuration of an example of the golf club shaft of the present invention.

  A golf club 10 shown in FIG. 1 includes a golf club shaft 12, a golf club head 14 provided at one end (tip end) of the golf club shaft 12, and a grip portion provided at the other end (butt end). 16.

The golf club head 14 is a wood-based golf club head, but may be an iron-based golf club head in the present invention.
The grip portion 16 is a portion where the golfer grips the golf club, and is provided by wrapping synthetic leather or resin around the butt end of the golf club shaft 12.
In the golf club of the present invention, the golf club head 14 and the grip portion 16 are not particularly limited.

The golf club shaft 12 is a golf club shaft configured using a metal film layer and a fiber reinforced resin layer.
As shown in the cross-sectional view of the golf club shaft in FIG. 2, the golf club shaft is mainly composed of a laminated material having five layers and is formed into a cylindrical shape.

The innermost layer is a fiber reinforced resin layer (hereinafter simply referred to as FRP layer) 24 made of a carbon fiber reinforced resin (CFRP) material in which carbon fibers are embedded as a reinforcing fiber in a matrix resin, and the outer layer is a titanium alloy. A metal foil thin film plate layer (hereinafter referred to as a metal film layer) 26 composed of a FRP layer 28 composed of a CFRP material in the same manner as the FRP layer 24, and a metal film layer 26 as an outer layer thereof. A metal film layer 30 made of the same titanium alloy and its outer layer are mainly made up of a total of five layers: an FRP layer 32 made of the same CFRP material as the FRP layer 24.
The metal film layers 26 and 30 have the same thickness, and both are formed by winding a rolled metal foil, and the rolling direction of the metal foil is substantially orthogonal to the longitudinal direction of the golf club shaft. Match the direction you want. FIG. 3 shows how the metal film layer 26 is formed by winding the metal foil 26 ′. In general, a rolled metal foil has a tensile strength in a direction perpendicular to the rolling direction with respect to a tensile strength in the rolling direction. Therefore, the tensile strength of the metal layers 26 and 30 along the longitudinal direction of the golf club shaft is formed by forming the metal film layers 26 and 30 so that the rolling direction coincides with the direction substantially orthogonal to the longitudinal direction of the golf club shaft. (Tensile strength in a direction with an inclination angle of 0 degree with respect to the longitudinal direction of the golf club shaft) can be effectively increased. In the present invention, as shown in FIG. 4, the rolling direction of the metal foil may be in the range of 60 to 120 degrees with respect to the longitudinal direction of the golf club shaft.

  Regarding the anisotropy of the tensile strength in such rolling process, it is desirable to increase the tensile strength along the longitudinal direction by 3% or more with respect to the tensile strength in the direction orthogonal to the longitudinal direction of the golf club shaft. In order to cause such anisotropy of the tensile strength in the titanium alloy, the rolling rate (ratio of thickness reduced by the rolling process) is preferably set to 20% to 80%, for example. This is because if the rolling rate is 80% or more, the metal foil is cracked, the thickness is not uniform, and the strength is lowered or warped.

  Each of the FRP layers 24, 28, and 32 is formed of a layered member formed by impregnating a matrix resin between reinforcing fibers having a certain orientation direction. For example, the FRP layer 24 is a layer in which two reinforcing fibers are inclined by ± 35 to 45 degrees with respect to the longitudinal direction of the golf club shaft, for example, two sheets are bonded and wound at an inclination angle of +45 degrees or −45 degrees. The FRP layers 28 and 32 are fiber reinforced layers in a range of an inclination angle of ± 30 degrees with respect to the longitudinal direction of the golf club shaft, that is, the orientation direction of the reinforcing fibers is relative to the longitudinal direction of the golf club shaft. The layer is inclined within a range of ± 30 degrees.

  Examples of the matrix resin in the FRP layers 24, 28, and 32 include thermosetting matrix resins such as epoxy resins, unsaturated polyester resins, polyurethane resins, diallyl phthalate resins, and phenol resins. Further, a curing agent or other imparting agent such as a flexibility imparting agent may be appropriately added so that the curing temperature is 50 to 200 degrees.

Among these, the matrix resin is preferably an epoxy resin. More specifically, for example, (1) glycidyl ether epoxy resin (bisphenol A, F, S epoxy resin, novolac epoxy resin, brominated bisphenol A epoxy resin); (2) cycloaliphatic epoxy resin (3) glycidyl ester epoxy resin; (4) glycidyl amine epoxy resin, tetraglycidyl diaminodiphenylmethane, triglycidyl-p-aminophenol, etc .; (5) heterocyclic epoxy resin; selected from various other epoxy resins One or more of these are preferred, and bisphenol A, F, and S glycidylamine epoxy resins are particularly suitable.
Examples of the curing agent to be applied include amine curing agents such as dicyandiamide (DICY), diaminodiphenylsulfone (DDS), diaminodiphenylmethane (DDM); acid anhydrides such as hexahydrophthalic anhydride (HHPA), methylhexahydro Phthalic anhydride (MHHPA) or the like is used. Of these, amine-based curing agents are particularly suitable.

  The reinforcing fibers of the FRP layers 24, 28, and 32 are carbon fibers, but are not limited to this in the present invention. For example, in addition to carbon fibers, inorganic fibers such as boron fibers, glass fibers, alumina fibers, silicon carbide fibers, and silicon nitride fibers, and organic fibers such as aramid fibers, polyarylate fibers, polyethylene fibers, and polyester fibers can be used. . Or metal fibers, such as a titanium fiber, an amorphous fiber, and a stainless steel fiber, may be sufficient. Furthermore, a plurality of types of fibers may be used in a hybrid form.

  Of the FRP layers 24, 28, and 32, the direction in which the fiber is reinforced within a range of an inclination angle of ± 30 degrees with respect to the longitudinal direction of the golf club shaft is the direction in which the reinforcing fibers are oriented. Further, the tensile strength of the reinforcing fibers along the line may be increased stepwise toward the outer layer side. However, the reinforcing fiber alone has a tensile strength in the orientation direction of the reinforcing fiber of 2500 MPa or more and a physical property of a specific gravity of 2.6 or less, which ensures the strength of the golf club shaft and makes the golf club shaft heavy. It is preferable in that it does not. As a material for such an FRP layer, an FRP material made of carbon fiber or aramid fiber is exemplified.

  Each of the metal film layers 26 and 30 is a titanium alloy, but in the present invention, the metal film layers 26 and 30 may be formed of a metal foil of other metal materials. Any metal material may be used as long as it has a tensile strength of 300 MPa or more and a specific gravity of 1.8 or more and 8.5 or less. Examples thereof include those made of metal materials such as stainless steel, iron, aluminum, copper, brass, nickel, nichrome, tin, lead, magnesium, gold, silver, platinum, and other various metals and alloys. In addition to titanium alloys, aluminum alloys, steels, magnesium alloys, maraging steels (hereinafter also referred to as maraging alloys), etc. all have the above properties. Examples of titanium alloys include Ti-15V-3Cr-3Al-3Sn, and examples of maraging alloys include YAG250 (trade name (composition: Fe-18Ni-8Co-5Mo-0.4Ti) manufactured by Hitachi Metals, Ltd. -0.1Al)). Examples of the aluminum alloy include high-strength aluminum alloys such as MESO10 (trade name) manufactured by Nippon Light Metal Co., Ltd.

  These metal materials can also be used by freely combining the metal film layers 26 and 30 with metal foils of the above various metal materials. In this case, a metal material having a high tensile strength along the longitudinal direction of the golf club shaft (with an inclination angle of 0 degrees) is used for the outer layer side (metal film layer 30) of the golf club shaft 12, that is, on the outer layer side. It is preferable to use a metal material so that the tensile strength increases stepwise as it goes, in terms of effectively improving the strength against bending deformation (bending deformation) of the golf club shaft. The high tensile strength means that, in the tensile strength, the larger tensile strength is 3% or more on the basis of the smaller tensile strength.

  At that time, the metal film layers 26 and 30 are formed so that the direction perpendicular to the rolling direction of the long metal foil is along the longitudinal direction of the golf club shaft, and the metal foil is 50 mm or more, most preferably the golf club shaft. It is preferably formed by wrapping over the entire length. The metal film layer 26 and the metal film layer 30 have the same thickness, but may be different, and the thickness of the metal film layers 26 and 30 is preferably 0.005 mm or more and 0.2 mm or less. In particular, in order to improve the hit feeling of the golfer, it is preferable to make it thicker than 0.1 mm and thinner than 0.2 mm.

  In the golf club shaft 12, the ratio of the total mass of the metal film layers 26 and 30 to the total mass of the golf club is 0.08 or more, and preferably the ratio is 0.4 to 0.8 or less. Furthermore, the ratio of the mass of the golf club shaft to the golf club shaft length is preferably 0.1 g / mm or less. In this way, by defining the mass of the metal film layers 26 and 30, it is possible to realize a better hitting feeling than conventional golf club shafts made of steel or golf club shafts made of FRP material.

  More specifically, the metal film layers 26 and 30 are provided with a resin film, and the metal film layers 26 and 30 are formed so as to adhere to the adjacent FRP layers by thermosetting the resin film. Yes. In this case, the resin film has a thickness of 0.02 to 0.2 mm, and is preferably a film including a carrier made of any one of glass fiber, carbon fiber, and synthetic fiber. Examples of the resin material of the resin film include thermoplastic resin films such as polyurethane resin, nylon resin, modified nylon resin, polyethylene terephthalate resin, polyvinyl chloride resin, polycarbonate resin, polyvinylidene chloride resin, ethyl cellulose resin, and cellulose acetate resin. . In particular, it is preferable to use a resin film that is highly compatible with the matrix resin in the FRP layer. For example, when an epoxy resin is used as the matrix resin, a polyurethane resin, a modified nylon resin film, or the like is preferable. Used.

  In addition, after applying a room temperature curable adhesive on the surface of the metal foil to be the metal film layers 26 and 30, the fiber reinforced resin material to be the FRP layer is adhered to the surface at room temperature to cure the adhesive at room temperature. Then, the FRP layers 26, 28, 32 may be formed by heating at the curing temperature of the fiber reinforced resin material. Here, the room temperature curable adhesive refers to an adhesive that cures at room temperature (15 to 30 ° C.). By using this adhesive, the adhesive is more bonded than when the adhesive is cured by conventional heat treatment. It is not necessary to perform a heat treatment for curing the agent, and deformation due to thermal distortion caused by heat can be suppressed. Examples of room temperature curable adhesives include rubber-modified epoxy adhesives.

  In the present embodiment, two metal film layers 26 and 30 are formed, and the metal foil is such that the direction perpendicular to the rolling direction of the metal foil is the longitudinal direction of the golf club shaft in any of these two layers. However, in the present invention, at least one layer may be formed of a rolled metal foil. Of course, in this case, the metal film layer may be formed so that the rolling direction is within a range of 60 to 120 degrees with respect to the longitudinal direction of the golf club shaft.

In the present embodiment, among the FRP layers 24, 28, and 32, a plurality of layers that are fiber reinforced in a range of an inclination angle of ± 30 degrees with respect to the longitudinal direction of the golf club shaft are all made of the same CFRP material. Although it comprised, in this invention, you may comprise with a different kind of FRP material.
Here, the different types of FRP materials are such that, in the tensile elastic modulus (Young's modulus) of the reinforcing fiber along the direction of the reinforcing fiber, the larger tensile elastic modulus is 10 on the basis of the smaller tensile elastic modulus to be compared. It means more than%. In this case, different types of reinforcing fibers (for example, carbon fiber and aramid fiber) are used for these multiple layers, and these reinforcing fibers have a stepwise tensile strength along the orientation direction of the reinforcing fibers toward the outer layer. It is preferable to use different types of reinforcing fibers so as to be larger. By comprising in this way, the intensity | strength with respect to the bending of a golf club shaft can be improved effectively. In this case, each layer can use different types of reinforcing fibers and different types of metal materials.
Here, “stepwise” means that the inner layer, the middle layer, and the outer layer have the same tensile strength in the order of the inner layer, the middle layer, and the outer layer, and the inner layer and the middle layer have the same tensile strength. The case where the tensile strength of the outer layer is large with respect to the strength, the case where the tensile strength of the middle layer and the outer layer are equal, and the case where the tensile strength of the inner layer is small with respect to the tensile strength are included.

Moreover, it is preferable that the elongation of the material of each layer used also becomes large in steps. Tensile elongation (breaking elongation) of the reinforcing fiber of the fiber reinforced resin layer reinforced by the reinforcing fiber within an inclination angle of ± 30 degrees and the length of the metal layer along the longitudinal direction of the golf club shaft (inclination angle of 0 degree). The tensile elongation (breaking elongation) is also preferably increased stepwise. It is preferable that a material having a high tensile strength and a large elongation is in the outer layer.
Moreover, in this embodiment, although the innermost layer and the outermost layer are comprised by the FRP layer, the innermost layer or the outermost layer may be comprised by the metal film layer.

  By using such a configuration, it is possible to improve the mechanical strength against bending (bending deformation) of the golf club shaft 12 at the time of hitting the golf ball, mainly bending strength (breaking strength). That is, in the deflection (bending deformation) of the golf club shaft 12, the central axis of the golf club shaft 12 functions as a substantially neutral axis. For this reason, the tensile strain and the compressive strain generated by this bending are maximized in the outermost layer of the golf club shaft. Therefore, in order to effectively suppress this tensile strain and compressive strain, particularly breakage due to tensile strain, the strength against the bending (bending deformation) of the golf club shaft is configured by configuring each layer so that the tensile strength becomes larger as the outer layer. Can be improved efficiently. At that time, the hit feeling can be improved at the same time by forming a plurality of metal film layers. Preferably, the hit feeling can be improved by setting the thickness of the metal film layer to 0.005 mm or more and 0.2 mm or less, and more preferably, the thickness is more than 0.1 mm and less than 0.2 mm. The hit feeling can be improved. That is, in the golf club shaft of the present invention, the strength against bending can be improved efficiently and a suitable hitting feeling can be presented to the golfer.

Various golf club shafts having such a laminated structure were produced, a golf club was assembled, and the strength against the deflection of the golf club shaft and the hit feeling when hitting a golf ball were examined.
As shown in Table 1 below, golf club shafts (samples # 1 to # 13) having different laminated structures were produced and the golf clubs were assembled.

Samples # 2, 4, 5, 7, 9, 11, and 13 correspond to the product of the present invention, and samples # 1, 3, 6, 8, 10, and 12 do not correspond to the product of the present invention. That is, the rolled metal foil forming the metal film layer corresponds to the direction in which the rolling direction is substantially orthogonal to the longitudinal direction of the golf club shaft in Samples # 2, 4, 5, 7, 9, 11, and 13. It is configured as follows.
In samples # 1 to 13, the first layer (innermost layer) to the outermost layer were formed to have a shaft length of 975 mm. W in Table 1 is the thickness in each layer, and each layer has a substantially uniform thickness, but the thickness at a position of 500 mm from the chip end is represented as a representative value.

  Samples # 1 and # 2 have metal film layers (second layer, fourth layer) made of titanium alloy and FRP layers (first layer, third layer, outermost layer) made of CFRP material using carbon fiber. Configured. Samples # 3, 4, and 5 have metal film layers (second layer, fourth layer, and sixth layer) made of a titanium alloy and FRP layers (first, third, and outermost layers) made of a CFRP material. Configured. Samples # 6 and # 7 have a metal film layer (second layer) made of a titanium alloy and an FRP layer (innermost layer) made of a CFRP material. Samples # 8 and # 9 consist of an FRP layer (innermost layer) made of AFRP material using aramid fibers, an FRP layer (third layer, outermost layer) made of CFRP material using carbon fibers, an aluminum alloy and a titanium alloy. And a metal film layer (second layer, fourth layer). Samples # 10 and # 11 are FRP layers (second layer, fourth layer, outermost layer) made of CFRP material using carbon fiber, and metal film layers (first layer) made of aluminum alloy, titanium alloy and maraging alloy. Layer, third layer, and fifth layer). Samples # 12 and 13 have the same configuration as samples # 10 and 11, but the thickness of the metal film layer is different.

  Further, at least one of the metal film layers of Samples # 2, 4, 5, 7, 9, 11, and 13 is formed so that the rolling direction of the metal foil coincides with the direction orthogonal to the longitudinal direction of the golf club shaft. Has been. Table 1 shows the angle θ between the rolling direction of the metal foil and the longitudinal direction of the golf club shaft. For example, in the metal film layers (second layer, fourth layer, and sixth layer) of sample # 3, the angle θ = 0 °, that is, the rolling direction coincides with the longitudinal direction of the golf club shaft. On the other hand, in the metal film layer of sample # 4, the angle θ = 90 ° in the fourth layer and the sixth layer, that is, the rolling direction and the longitudinal direction of the golf club shaft are orthogonal to each other. In the metal film layer of sample # 5, the angle θ is 90 ° in the sixth layer.

By the way, the titanium alloy is Ti-15V-3Cr-3Al-3Sn, the aluminum alloy is made by Nippon Light Metal Co., Ltd., the high-strength aluminum alloy MESO10 (trade name), the maraging alloy is made by Hitachi Metals, YAG250 (product name ( Composition: Fe-18Ni-8Co-5Mo-0.4Ti-0.1Al)). The respective tensile strengths are 1300 MPa, 780 MPa and 1800 MPa in order. That is, the magnitude of the tensile strength is greatest for the maraging alloy, and is in the order of titanium alloy and aluminum alloy.
Further, in the FRP layer using the CFRP material and the FRP layer using the AFRP material, the tensile strength of the reinforcing fiber along the orientation direction of the reinforcing fiber is FRP layer using the AFRP material in the FRP layer using the CFRP material. It is larger than the layer.

Moreover, the FRP layer using the CFRP material and AFRP material in Table 1 is obtained by impregnating an epoxy resin as a matrix resin between reinforcing fibers. On the other hand, the titanium alloy is a titanium alloy having a composition of Ti-15V-3Cr-3Al-3Sn. The aluminum alloy is an alloy having a composition of Al-9.5Zn-3Mg-1.5Cu-0.04Ag. In addition, each layer using the CFRP material and the AFRP material was composed of two to three layers, and the orientation angles of the respective fibers were set to 0 °, 90 °, 45 °, 60 °, and the like.
Samples # 1 to # 13 all used a resin film made of polyurethane resin for adhesion between the FRP layer and the metal film layer.

Table 2 below shows the characteristics of samples # 1 to # 13.

  Samples # 1 to # 13 all have a golf club shaft mass / golf club shaft length ratio of 0.1 g / mm or less. Further, the ratio of the total mass of the metal film layer to the mass of the golf club shaft is 0.08 or more, and this ratio is 0.4 to 0.8 or less.

  Table 3 below shows the evaluation results of the strength against bending of golf clubs assembled by attaching the golf club heads made of titanium alloy and the clip parts to the golf club shafts of the samples # 1 to # 13 and the evaluation of the hit feeling by the golfer. Results are shown.

The strength against the deflection of the golf club shaft is determined by the Product Safety Association according to the certification standards of the golf club shaft and the standard confirmation method (approved by the Minister of International Trade and Industry, No. 2087, October 4, 1993). It investigated according to the measurement of the strength A point of the C-shaped shaft. Specifically, the golf club shaft is supported at a distance of 300 mm, a load is applied to the midpoint, a three-point bending test is performed, and the maximum load when the golf club shaft breaks due to bending deformation is measured as the strength. Turned into. Indexing is a sample having the same structure, and the rolling direction of the metal foil in any metal film layer matches the longitudinal direction of the golf club shaft (angle θ = 0 °). Samples # 1, 3, 6, 8, The strengths of 10 and 12 were 100 (reference). For example, sample # 2 is based on sample # 1 having the same structure.
As is apparent from Table 3, the samples # 2, 4, 5, 7, 9, 11, and 13 which are products of the present invention have an improvement in strength index of at least 5 or more.

On the other hand, a golf ball was struck and a test shot was made, and ten golf players were subjected to sensory evaluation. The sensory evaluation of samples # 2, 4, 5, 7, 9, 11, and 13 does not change with each sample # 1, 3, 6, 8, 10, and 12 having the same structure as the reference (0). A good impression (+1), a good impression (+2), a slightly inferior impression (-1), and an inferior impression (-1) were evaluated in five stages.
None of the samples # 2, 4, 5, 7, 9, 11, and 13 was different from the samples # 1, 3, 6, 8, 10, and 12 serving as the respective references having the same structure. That is, the hit feeling felt by the golfer did not change with respect to the standard.

  From the above results, the golf club shaft of the present invention can effectively improve the strength against bending of the golf club shaft while maintaining the hit feeling felt by the golfer. In other words, the strength against the deflection of the golf club shaft is effectively improved by forming the metal film layer by arranging the rolled metal foil so that the rolling direction is substantially perpendicular to the longitudinal direction of the golf club shaft. Can be made.

  The golf club shaft and golf club of the present invention have been described in detail above. However, the present invention is not limited to the above examples and embodiments, and various improvements and modifications are made without departing from the gist of the present invention. Of course.

It is a perspective view which shows an example of the golf club of this invention using the golf club shaft of this invention. FIG. 2 is a cross-sectional view taken along the line A-A ′ in FIG. 1 showing the configuration of the golf club shaft of the present invention. It is a figure explaining the formation method of the metal foil thin film board layer in the golf club shaft of this invention. It is a figure explaining the rolling direction of the metal foil in the golf club shaft of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Golf club 12 Golf club shaft 14 Golf club head 16 Grip part 24,28,32 Fiber reinforced resin layer 26,30 Metal foil thin film board layer 26 'Metal foil

Claims (15)

A golf club shaft configured by laminating a fiber reinforced resin layer and a metal film layer,
The metal film layer is formed by winding a rolled metal foil, and the rolling direction of the metal foil is set in a range of 60 to 120 degrees with respect to the longitudinal direction of the golf club shaft. And golf club shaft.   The metal film layer is formed in a plurality of layers, and the rolling direction of the metal foil in at least one of the plurality of layers is set in a range of 60 to 120 degrees with respect to the longitudinal direction of the golf club shaft. The golf club shaft described in 1.   A plurality of the metal film layers are formed, and metal foils of metal materials having different tensile strengths along the longitudinal direction of the golf club shaft are used for the plurality of layers, and the metal material having a high tensile strength. The golf club shaft according to claim 1, wherein is used on the outer layer side.   The metal film layer is formed in a plurality of layers, and in these layers, the tensile strength along the longitudinal direction of the golf club shaft increases stepwise as it goes to the outer layer. The golf club shaft according to claim 3, wherein metal foils made of different metal materials are used.   The golf club shaft according to any one of claims 1 to 4, wherein the metal film layer has a thickness of 0.005 mm or more and 0.2 mm or less.   The golf club shaft according to claim 1, wherein a metal material having a specific gravity of 8.5 or less is used for the metal foil of the metal film layer.   The metal foil is a long foil whose rolling direction is set to a range of 60 to 120 degrees with respect to the longitudinal direction of the golf club shaft, and the metal film layer is golfed in the longitudinal direction of the metal foil. The golf club shaft according to any one of claims 1 to 6, wherein the metal foil is formed by winding 50 mm or more along the longitudinal direction of the club shaft.   The golf club shaft according to any one of claims 1 to 7, wherein a ratio of a total mass of the metal thin film layer to a mass of the golf club shaft is 0.08 or more.   The fiber reinforced resin layer is formed in a plurality of layers as a layer reinforced at least partially within a range of an inclination angle of ± 30 degrees with respect to the longitudinal direction of the golf club shaft. The reinforcing fiber having a different tensile strength or a different type of reinforcing fiber is used in which the tensile strength of the reinforcing fiber along the orientation direction of the reinforcing fiber increases stepwise toward the outer layer. 2. A golf club shaft according to item 1.   The golf club shaft according to any one of claims 1 to 9, wherein a ratio of a mass of the golf club shaft to a length of the golf club shaft is 0.1 g / mm or less.   The golf club shaft according to any one of claims 1 to 10, wherein the metal film layer is formed by providing a resin film between the metal reinforced resin layer and the fiber reinforced resin layer. .   The golf club shaft according to claim 11, wherein the resin film is a film having a thickness of 0.02 to 0.2 mm and including a carrier made of any one of glass fiber, carbon fiber, and synthetic fiber. .   The metal film layer is formed of a metal foil, and after applying a room temperature curable adhesive to the surface of the metal foil, a fiber reinforced resin material to be the fiber reinforced resin layer is provided on the coated surface, and the adhesive is used at room temperature. The golf club shaft according to any one of claims 1 to 10, wherein the fiber reinforced resin layer is formed by curing at a curing temperature of the fiber reinforced resin material.   The reinforcing fiber in the fiber reinforced resin layer has physical properties of a tensile strength in the orientation direction of the reinforcing fiber of 2500 MPa or more and a specific gravity of 2.6 or less, and the metal foil in the metal film layer is a longitudinal axis of the golf club shaft. The golf club shaft according to any one of claims 1 to 13, wherein the golf club shaft has physical properties of a tensile strength along a direction of 300 MPa or more and a specific gravity of 1.8 or more. 15. A golf club, wherein a grip portion is provided at one end of the golf club shaft according to claim 1 and a golf club head is provided at the other end.

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