JP5677354B2 - Golf club shaft - Google Patents

Description

  The present invention relates to a golf club shaft.

  A carbon shaft produced by laminating a plurality of prepreg sheets is widely used as a golf club shaft. The prepreg sheet includes a straight layer sheet in which the fiber orientation direction substantially coincides with the shaft axis direction, and a bias layer sheet in which the fiber orientation direction is inclined by a predetermined angle with respect to the shaft axis direction. By winding the straight layer sheet, the bending rigidity and bending strength of the shaft can be increased. On the other hand, the torsional rigidity and torsional strength of the shaft can be increased by winding the bias layer sheet. By laminating the straight layer sheet and the bias layer sheet, it is possible to adjust the bending rigidity or torsional rigidity of the shaft and design a shaft having desired characteristics.

  In addition to the sheet provided over the entire length in the axial direction of the shaft, such as the sheet for the straight layer and the bias layer, a part of the shaft in the axial direction has a length shorter than the total length in the axial direction of the shaft. A partial sheet can be provided. There is an example of disclosure of such a partial sheet. For example, Japanese Patent Application Laid-Open No. 2009-254601 (Patent Document 1) discloses a partial sheet for partially increasing the bending rigidity and torsional rigidity of the shaft on the full-length bias sheet disposed over the entire length of the shaft. Is disclosed. Further, in JP 2011-56118 A (Patent Document 2), a damping material sheet 40 made of a polyester-based resin composition in which a filler is dispersed is disposed between two prepreg sheets for a bias layer, and hit. It is disclosed to suppress the vibration of the shaft at the time.

JP 2009-254601 A JP 2011-056118 A

  However, there is no known method for increasing both rigidity and vibration damping by a partial sheet. For example, the partial sheet described in Patent Document 1 is not configured to exhibit a vibration damping action. Patent Document 2 describes that the rigidity of the portion provided with the damping material sheet 40 is reduced (see paragraph [0029]).

  Therefore, according to an embodiment of the present invention, there is provided a golf club shaft in which rigidity and vibration damping are both enhanced by using a partial sheet.

  A golf club shaft according to an embodiment of the present invention is a golf club shaft extending in the shaft axial direction. A golf club shaft according to an embodiment includes a partial sheet provided at a portion other than both ends of the shaft in the axial direction of the shaft, and a full-length prepreg sheet provided over the entire length in the axial direction of the shaft so as to cover the partial sheet. , Provided. In one embodiment, the partial sheet is less elastic than the full length prepreg sheet.

  According to the embodiment of the present invention, it is possible to provide a golf club shaft in which both rigidity and vibration damping are enhanced by using a partial sheet.

Schematic of a golf club provided with a golf club shaft according to an embodiment of the present invention The figure which shows an example of arrangement | positioning of the prepreg sheet wound around the golf club shaft which concerns on one Embodiment of this invention.

  Hereinafter, various embodiments of the present invention will be described with reference to the accompanying drawings. In the drawings, common components are denoted by common reference numerals. It should also be noted that the drawings are not necessarily drawn to scale for convenience of explanation.

  FIG. 1 is a schematic overall view of a golf club provided with a golf club shaft according to an embodiment of the present invention. The golf club 1 includes a hollow shaft 10, a head 50 attached to the tip 30 of the shaft 10, and a grip 60 attached to the tip 40 of the shaft 10.

  The shaft 10 is a hollow carbon shaft made of a cured prepreg sheet. The prepreg sheet is formed by impregnating a reinforcing resin with a matrix resin. Examples of the reinforcing fiber include, but are not limited to, carbon fiber, glass fiber, alumina fiber, and boron fiber. The matrix resin includes, but is not limited to, thermosetting resins such as epoxy resins, phenol resins, and polyesters, thermoplastic resins, and the like. The shaft 10 is usually formed so as to gradually increase in diameter from the tip 30 toward the tip 40. A taper may be provided at portions other than both ends of the shaft 10 in the axial direction of the shaft 10 to adjust the rigidity distribution in the axial direction of the shaft 10.

  FIG. 2 is a diagram illustrating an arrangement example of the prepreg sheets constituting the shaft 10 according to the embodiment of the present invention. When the shaft 10 is manufactured, as shown in the drawing, sheets 21 to 27 cut to a predetermined size are prepared, and these sheets are sequentially wound around the mandrel M. The sheets 21 to 27 are the prepreg sheets described above. As will be described later, the sheet 21 is a low elastic sheet formed with lower elasticity than the sheets 23 to 26 that cover the sheet 21 in the wound state. The characteristics of the shaft 10 can be changed by adjusting the material, dimensions, arrangement, fiber orientation, and the like of these sheets.

  On the left shoulders of the sheets 22 to 27, the fiber orientation of the prepreg sheet is schematically shown. For example, a line parallel to the axial direction of the shaft 10 (corresponding to the long axis direction of the mandrel M in FIG. 2) is drawn on the left shoulders of the sheet 22 and the sheets 24 to 27. A line parallel to the shaft axial direction represented on these sheets indicates that the fiber orientation direction of the sheet on which the line is displayed substantially coincides with the shaft axial direction. For reasons of space, the sheet 21 is not provided with a line indicating the fiber orientation direction, but, like the sheets 22 to 27, the sheet 21 also includes fibers having a predetermined orientation direction. In the present specification, the prepreg sheet in which the fiber orientation direction coincides with the shaft axis direction is sometimes referred to as a “straight sheet”. Due to manufacturing errors, the fiber orientation direction does not completely coincide with the shaft axis direction, and it may be slightly tilted with respect to the shaft axis direction. In this case, however, the fiber orientation direction coincides with the shaft axis direction. Can be considered. The straight sheet can be used to increase the bending rigidity of the shaft.

  The sheet 22 and the sheet 27 are straight sheets provided near the tip 30 of the shaft 10. The sheet 22 constitutes the lowermost layer of the shaft 10 as illustrated. The sheet 22 and the sheet 27 are provided in order to give rigidity to the tip 30 where the stress of the shaft 10 is concentrated at the time of hitting.

  The sheet 23 is a bias sheet formed by bonding two sheets having different fiber orientation directions. In the example shown in FIG. 2, the sheet 23 includes a lower layer sheet 23 a in which the fiber orientation direction is inclined about 45 ° upward with respect to the shaft axial direction, and the fiber orientation direction is about 45 downward with respect to the shaft axial direction. The upper layer sheet 23b which is inclined is bonded to the upper layer sheet 23b. The bias sheet can be used to increase the torsional rigidity of the shaft.

  The sheet 23 to the sheet 26 are provided over the entire length of the shaft 10 in the shaft axial direction. However, in this specification, a sheet provided over the entire length in the shaft axial direction may be referred to as a full length sheet, a full length prepreg, or a full length prepreg sheet.

  On the other hand, the sheet 21, the sheet 22, and the sheet 27 are not provided over the entire length in the shaft axial direction because the shaft axial dimension is shorter than the shaft axial dimension of the shaft 10. Such a sheet not provided over the entire length in the axial direction of the shaft may be referred to as a partial sheet, a partial prepreg, or a partial prepreg sheet in the present specification.

  The sheet 21 is a low elastic sheet made of a material having lower elasticity than the sheets 23 to 26. For example, the sheet 21 is made of a metal prepreg or a glass prepreg, but any sheet of any material, shape, and size can be used as long as it is less elastic than the sheets 23 to 26. The metal prepreg may be one in which metal fibers formed of titanium, iron, tungsten, copper, aluminum, etc. are substantially aligned in the axial direction of the shaft and impregnated with synthetic resin, titanium mesh, metal powder It may be a resin sheet or a fiber in which a metal film such as titanium is formed. The glass prepreg is made of glass fiber woven and impregnated with a synthetic resin. Since the sheet 21 is formed of a material having lower elasticity than the sheets 23 to 26, the sheet 21 is more excellent in vibration damping characteristics than the sheets 23 to 26. That is, the vibration transmitted from the head 50 to the shaft at the time of hitting the ball is damped more efficiently than the sheets 22 to 27 by the sheet 21.

  In one embodiment, the sheet 21 is provided at a portion other than both ends of the shaft 10 in the shaft axial direction. In other words, the front end of the sheet 21 (the front end of a sheet element 21a described later) is separated from the front end 30 of the shaft 10 by a predetermined distance, and the rear end (the rear end of a sheet element 21b described later) is separated from the base end 40. It is arranged at a position separated by a predetermined distance.

  As illustrated, the sheet 21 includes a first sheet element 21a and a second sheet element 21b. The sheet 21 is arranged such that the first sheet element 21a is located on the distal end 30 side and the second sheet element 21b is located on the proximal end 40 side. FIG. 2 shows an example in which the sheet 21 is composed of two sheet elements, but the sheet 21 can be composed of an arbitrary number of sheet elements. For example, the sheet 21 can be composed of three sheet elements.

  In one embodiment, the second sheet element 21b is formed thicker than the first sheet element 21a. Thereby, in the region where the sheet 21 is provided, the rigidity on the proximal end 40 side of the shaft 10 is higher than the rigidity on the distal end 30 side, and the difference in rigidity between the proximal end 40 side and the distal end 30 side can be more emphasized. it can.

  In other embodiments, the first sheet element 21a is formed thicker than the second sheet element 21b. As a result, in the region where the sheet 21 is provided, the rigidity on the distal end 30 side of the shaft 10 is higher than the rigidity on the proximal end 40 side, and the position where the deflection becomes larger is on both sides of the sheet 21 (the distal end 30 side and the proximal end 40). Side). When the sheet 21 includes three sheet elements, for example, each sheet element is arranged so that the sheet element disposed on the distal end 30 side is the thinnest and the sheet element disposed on the proximal end 40 side is the thickest. Can be formed.

  The materials, dimensions, arrangement, fiber orientation, and other characteristics of the sheets 21 to 27 are not limited to those specified in the present specification, and can be appropriately changed according to the desired characteristics of the shaft 10.

  The shaft 10 described above is manufactured in the following procedure, for example, according to the sheet winding method. First, the prepreg sheet is cut into the shapes of the sheets 21 to 27. Next, the cut sheet is bonded to produce a sheet 23 that is a bias sheet. The sheet 21 is obtained by connecting the sheet element 21a and the sheet element 21b obtained by cutting separately. Next, the cut sheets 21 to 27 are sequentially wound around the mandrel M to obtain a wound body. In this wound body, the sheet 21 and the sheet 22 are the lowermost layer, and the sheet 27 is the uppermost layer. Next, the wound body is heated to cure the matrix resin, and then the mandrel M is pulled out to obtain the hollow shaft 10. After this, surface polishing or paint post-treatment is performed as necessary.

  In the shaft 10 for the golf club 1 according to the embodiment of the present invention, since the low-elasticity partial sheet 21 is disposed in the lowermost layer, the vibration damping action by the partial sheet 21 is obtained. In addition, since the height in the shaft radial direction of the full length sheets 23 to 26 can be increased at the position where the partial sheet 21 is provided, the rigidity of the shaft 10 can be increased at the position where the partial sheet 21 is provided. it can. By using a straight sheet having a high effect of increasing the bending rigidity as the full length sheets 23 to 26, the bending rigidity can be further increased. In addition, torsional rigidity can be increased by using a bias sheet. Thus, according to the shaft 10 which concerns on one Embodiment of this invention, both rigidity and vibration damping can be improved using the partial sheet | seat 21. FIG.

  The dimensions, materials, and arrangements of each component described herein are not limited to those explicitly described in the embodiments, but rather are any dimensions, materials, And each component can be modified to have an arrangement. In addition, components other than those explicitly described in the present specification can be added to the described embodiments, and some of the components described in the embodiments can be omitted.

DESCRIPTION OF SYMBOLS 1 Golf club 10 Shaft 30 Tip 40 Base end 50 Head 21-27 Sheet M Mandrel

Claims (3)

A golf club shaft extending in the axial direction of the shaft,
Partial sheets provided on portions other than both ends of the shaft in the axial direction of the shaft;
A full length prepreg sheet provided over the entire length in the shaft axial direction so as to cover the partial sheet;
With
The partial sheet is less elastic than the full length prepreg sheet,
The partial sheet includes a first sheet portion and a second sheet portion thicker than the first sheet portion;
A golf club shaft in which the partial seat is disposed such that the first seat portion is located on a distal end side of the shaft and the second seat portion is located on a proximal end side of the shaft. A golf club shaft extending in the axial direction of the shaft,
Partial sheets provided on portions other than both ends of the shaft in the axial direction of the shaft;
A full length prepreg sheet provided over the entire length in the shaft axial direction so as to cover the partial sheet;
With
The partial sheet is less elastic than the full length prepreg sheet,
The partial sheet includes a first sheet portion and a second sheet portion thicker than the first sheet portion;
A golf club shaft in which the partial seat is disposed such that the first seat portion is located on a proximal end side of the shaft and the second seat portion is located on a distal end side of the shaft. The golf club shaft according to claim 1, wherein the partial sheet is made of a metal prepreg or a glass prepreg.

Images