JP4331997B2 - Golf club shaft and manufacturing method thereof, and golf club and manufacturing method thereof - Google Patents

Description

  The present invention relates to a golf club shaft made of fiber reinforced resin using carbon fiber, glass fiber, or the like, and a method for manufacturing the same, and more particularly to a golf club shaft capable of suppressing variation in feeling (use feeling) at the time of swing, and It relates to the manufacturing method.

  Golf manufactured using a fiber reinforced synthetic resin sheet (prepreg sheet) having a structure in which a high-strength fiber such as carbon fiber or glass fiber is impregnated with a synthetic resin base material such as epoxy resin or polyester resin as a shaft for a golf club Club shafts are widely used. This type of shaft is manufactured by a sheet rolling method, in which a plurality of fiber-reinforced synthetic resin sheets with fibers oriented in a predetermined direction are sequentially wound around a mandrel so that the fiber direction is in the predetermined direction. After that, an integrated multi-layered shaft is formed by placing in an electric furnace or the like and firing to melt and solidify the impregnated fibers.

In this case, if the joints of the fiber-reinforced synthetic resin sheets in each layer (the mating surface of the winding start end and the winding end end) are unevenly distributed in the circumferential direction, the strength and rigidity in the circumferential direction of the shaft will be uneven. Therefore, Patent Document 1 below proposes a structure in which the joints of the fiber-reinforced synthetic resin sheets of each layer are uniformly distributed so as not to be unevenly distributed in the circumferential direction.
Japanese Patent No. 2705047

  However, even when a golk club is manufactured using a shaft having a structure in which the joints of fiber reinforced synthetic resin sheets in each layer are distributed in the circumferential direction, the feeling at the time of swing is slightly different for each gork club. There is. It is considered that the main cause of the variation in the feeling is a shift in the fiber orientation direction at the joint of the fiber reinforced synthetic resin sheets of each layer.

  That is, the shaft has a slightly tapered shape in the axial direction so that the tip end side to which the head is attached is thin and the rear end side to which the grip is attached is thick. Therefore, the outer peripheral surface of the mandrel for forming the shaft is a conical surface, and the fiber-reinforced synthetic resin sheet is wound around in a conical shape. For this reason, as shown to Fig.3 (a), the fiber reinforced synthetic resin sheet 40 to wind becomes a thing with a wide rear end side. As a result, as shown in FIG. 3B, when the mandrel is wound around the outer peripheral surface so that the fiber orientation direction X coincides with the axial direction 41a of the mandrel 41, the fiber orientation direction X is on the winding start end 40a side. Although parallel to the axial direction 41a, the fiber orientation direction X of the winding end 40b is a direction that intersects the axial direction 41a at a predetermined angle.

  Thus, the fiber orientation direction of the fiber reinforced synthetic resin sheet of each layer is slightly shifted from the shaft axis in the circumferential direction of the shaft, and a large shift occurs between the winding start end and the winding end end at the joint. For this reason, even if the joints of the layers are distributed evenly in the circumferential direction of the shaft, the physical characteristics in the circumferential direction of the shaft still have a slight non-uniformity within generally accepted tolerances. Due to such unevenness in strength and rigidity in the circumferential direction of the shaft, a difference in feeling at the time of swing appears between the golf clubs.

  An object of the present invention is to propose a golf club shaft made of fiber-reinforced resin capable of suppressing such variation in feeling during swing, a manufacturing method thereof, and a golf club and a golf club manufacturing method using the shaft. There is to do.

In order to solve the above problems, the shaft for a golf club of the present invention comprises:
Consists of a multi-layered cylindrical body composed of a plurality of fiber-reinforced synthetic resin sheets,
The fiber-reinforced synthetic resin sheet of each layer is wound in a cylindrical shape so that a joint where the winding start end and the winding end end are abutted is formed,
The fiber reinforced synthetic resin sheet of each layer so that the joint of each layer defining the winding start position and the winding end position of the fiber reinforced synthetic resin sheet of each layer has a predetermined positional relationship between the layers. Is wound in a cylindrical shape,
The shaft outer peripheral surface, of the joint of the fiber-reinforced synthetic resin sheet, an indicator for defining the positional relationship of the face surface of the head against the seam of the outermost of the fiber reinforced synthetic resin sheet is formed It is characterized by having.

The golf club shaft of this configuration is
Each fiber reinforced synthetic resin sheet forming each layer is sequentially wound around the outer peripheral surface of the mandrel to form a multilayer tubular body,
On the outer peripheral surface of the fiber reinforced synthetic resin sheet wound on the outermost side, a mark representing the position of the joint of the fiber reinforced synthetic resin sheet is attached,
After the cylindrical body is integrated by firing, the mandrel is pulled out,
Surface treatment is applied to the cylindrical body,
Thereafter, it can be manufactured by printing the index at a predetermined position on the outer peripheral surface of the cylindrical body based on the mark.

Next, in the golf club and the manufacturing method thereof according to the present invention, the position of the face surface of the head attached to the tip of the golf club shaft is set to the outermost side with reference to the formation position of the index of the golf club shaft having the above configuration. It is characterized by prescribing | regulating so that it may become a predetermined positional relationship with respect to the said joint of the said fiber reinforced synthetic resin sheet wound .

In the golf club shaft of the present invention, correlation of the joint of the fiber reinforced synthetic resin sheet layers (end end-out winding start end and the winding) it is predetermined, the outer peripheral surface is an index representing the positional relationship Is formed. Therefore, based on this index, the head can be attached to the tip of the shaft so that the face surface of the head has a fixed angular positional relationship with respect to the joint of each layer.

  As described above, in the present invention, since the angular position of the joint of the fiber-reinforced synthetic resin sheet of each layer can be confirmed when the head is attached, each golf club also has a relative relationship between the angular position of the joint and the angular position of the head face surface. Becomes constant. As a result, it is possible to obtain an effect that variation in feeling during swing between golf clubs is suppressed.

  Hereinafter, the present invention will be described in detail with reference to the drawings.

  FIG. 1 (a) is a front view showing a golf club to which the present invention is applied, and FIG. 1 (b) is a transverse sectional view showing a shaft section thereof. The golf club 1 includes an elongated cylindrical shaft 2, a head 3 attached to the tip of the shaft 2, and a grip 4 attached to the rear end of the shaft 2. The shaft 2 has a small front end on the head side and a large rear end on the grip side, and the diameter between them gradually increases from the front end side toward the rear end side.

  The shaft 2 is formed of a cylindrical body in which layers of fiber-reinforced synthetic resin sheets are formed concentrically. In this example, the first to fifth layers 11 to 15 are formed from the inside to the outside. A logo mark 17 is printed on the surface of the surface treatment layer 16 such as a coating formed on the outermost periphery of the shaft 2. The fibers contained in the fiber reinforced synthetic resin sheets of the layers 11 to 15 include carbon fibers, polyamide fibers, boron fibers, metal fibers, glass fibers, or unidirectional fibers or woven fibers composed of two or more of these. Cloth fiber etc. are used. Moreover, as a synthetic resin as a base material, epoxy resin, melamine resin, phenol resin, thermoplastic nylon, polycarbonate resin, or the like can be used. The fiber reinforced synthetic resin sheets of the respective layers 11 to 15 may be used in combination of the same type or different types according to physical properties required for the shaft 2, such as strength, rigidity, and impact strength.

  Here, in this example, the joint 12a of the outer second layer 12 is offset by 90 degrees clockwise with respect to the joint 11a between the winding start end and the winding end end of the innermost first layer 11. The angle position. Similarly, the seam 13a of the third layer 13 is offset 90 degrees clockwise relative to the seam 12a of the second layer, and the seam 14a of the fourth layer 14 is the seam of the third layer 13. 13a is also offset 90 degrees clockwise, and the seam 15a of the outermost fifth layer 15 is also offset 90 degrees clockwise relative to the seam 14a of the fourth layer 14a. The logo mark 17 of this example is formed at an angular position offset 90 degrees clockwise relative to the joint 15a of the outermost fifth layer 15.

  The head 3 is attached to the tip of the shaft 2 with the printing position of the logo mark 17 as a reference. In other words, the head 3 is attached to the tip of the shaft so that the face surface 3a extends in a radial direction from an angular position offset by 45 degrees clockwise relative to the logo mark 17, for example.

  Next, FIG. 2 is a schematic flowchart of the manufacturing process of the golf club 1 with a focus on the manufacturing process of the shaft 2. In manufacturing the shaft 2, first, the first to fifth fiber-reinforced synthetic resin sheets 21 to 25 for forming the respective layers 11 to 15 of the shaft 2 are prepared, and a core bar for winding them is prepared. A mandrel 20 is prepared (step ST1).

  The first fiber-reinforced synthetic resin sheet 21 is wound around the outer peripheral surface of the mandrel 20 so that the winding start end and the winding end end are abutted. Similarly, the 2nd-5th fiber reinforced synthetic resin sheets 22-25 are wound in order (process ST2). Each of the sheets 21 to 25 has a predetermined fiber orientation direction at the time of winding. In addition, as described above, the positions of the joints 21a to 25a (the mating surfaces of the respective winding start ends and winding end ends) of the sheets 21 to 25 are set so that the outer layer is rotated clockwise by 90 degrees with respect to the inner layer. They are wrapped so that they are angular positions offset by degrees. In this way, the cylindrical body 30 having a five-layer structure is obtained by winding the sheets 21 to 25.

  Next, a mark 27 for indicating the angular position of the joint 25a of the sheet 25 is drawn on the outer peripheral surface of the outermost sheet 25 of the cylindrical body 30 using oil-based ink or the like (step ST3). Thereafter, a wrapping tape for fastening and fixing the cylindrical body 30 is wound from the outside to fix the cylindrical body 30, and in this state, the cylindrical body 30 is placed in an electric furnace and fired (step ST4). . A cylindrical body in which the first to fifth layers 11 to 15 made of the respective sheets 21 to 25 are integrated by the synthetic resin that is a base material of the respective sheets 21 to 25 being melted and re-cured by baking. 30 is formed.

Thereafter , the mandrel 20 is pulled out, and then the wrapping tape is removed from the surface of the cylindrical body 30, and the surface of the cylindrical body 30 is polished (step ST5). Next, the cylindrical body is subjected to a surface treatment to form a surface treatment layer 16 such as a coating (step ST6). And the logo mark 17 is printed on the site | part which had the mark 26, and the shaft 2 is completed (process ST7).

  A separately prepared head and grip are attached to the shaft 2 thus obtained, thereby completing a golf club (ST8). Here, the logo 17 on the shaft 2 is printed at an angular position 90 degrees clockwise with respect to the joint 15a of the outermost layer 15 (see FIG. 1B). The head 3 is attached to the tip of the shaft with reference to the printing position of the logo mark 17. Therefore, in each manufactured golf club, the relationship between the angular positions of the joints 11a to 15a of the layers 11 to 15 of the shaft 2 and the mounting angular position of the face surface 3a of the head 3 is constant. As a result, variation in feeling during swinging between golf clubs is suppressed.

(Other embodiments)
In the above example, the joints of the layers of the shaft 2 are offset by 90 degrees, but the relative positional relationship of the joints of the layers may be offset by an angle other than 90 degrees. Further, although the logo mark (index) 17 is formed at a position offset 90 degrees clockwise from the joint of the outermost layer, the logo mark may be formed at the same position as the joint. Instead, it may be formed at a position offset by an angle other than 90 degrees. In any case, in the head assembling step, an index such as a logo mark may be attached so that the position of the joint of each layer of the shaft can be confirmed and the head mounting position can be determined based on this.

  The above example is a shaft having a five-layer structure, but the present invention can be similarly applied to a shaft having a layer structure smaller than this and a shaft having a layer structure larger than this.

  Further, the shaft 2 has a configuration in which the fiber-reinforced synthetic resin sheets of each layer are wound one by one so that the winding start end and the winding end end are brought together. One or a plurality of layers may be formed from a fiber reinforced synthetic resin sheet wound in two or more turns. Furthermore, in general, the winding start end and the winding end end of the sheets of each layer are at the same position, but may be at different positions.

(A) is a front view which shows an example of the golf club to which this invention is applied, (b) is a cross-sectional view which shows the shaft cross section. 2 is a flowchart showing a method for manufacturing the golf club of FIG. 1 centering on a method for manufacturing a shaft. It is explanatory drawing for demonstrating the problem of the shaft for golf clubs in the past.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Golf club 2 Shaft 3 Head 4 Grip 11-15 Fiber reinforced synthetic resin sheet layer 16 Surface treatment layer 17 Logo mark 20 Mandrels 21-25 Fiber reinforced synthetic resin sheet 27 forming each layer Mark 30 Cylindrical body

Claims (4)

Consists of a multi-layered cylindrical body composed of a plurality of fiber-reinforced synthetic resin sheets,
The fiber-reinforced synthetic resin sheet of each layer is wound in a cylindrical shape so that a joint where the winding start end and the winding end end are abutted is formed,
The fiber reinforced synthetic resin sheet of each layer so that the joint of each layer defining the winding start position and the winding end position of the fiber reinforced synthetic resin sheet of each layer has a predetermined positional relationship between the layers. Is wound in a cylindrical shape,
The shaft outer peripheral surface, of the joint of the fiber-reinforced synthetic resin sheet, an indicator for defining the positional relationship of the face surface of the head against the seam of the outermost of the fiber reinforced synthetic resin sheet is formed Shaft for golf clubs. A shaft for a golf club according to claim 1;
The position of the face surface of the head attached to the tip of the golf club shaft is in a predetermined positional relationship with respect to the joint of the outermost fiber-reinforced synthetic resin sheet, with the formation position of the index as a reference. A golf club having a head as defined in 1. It is a manufacturing method of the shaft for golf clubs of Claim 1, Comprising:
Each fiber reinforced synthetic resin sheet forming each layer is sequentially wound around the outer surface of the mandrel to form a multilayered tubular body,
On the outer peripheral surface of the fiber reinforced synthetic resin sheet wound on the outermost side, a mark indicating the position of the joint of the fiber reinforced synthetic resin sheet is attached,
After the cylindrical body is integrated by firing, the mandrel is pulled out,
Surface treatment is applied to the cylindrical body,
Thereafter, a golf club shaft manufacturing method for printing the index at a predetermined position on the outer peripheral surface of the cylindrical body based on the mark. A golf club manufacturing method using the golf club shaft according to claim 1,
Based on the formation position of the indicator, the position of the face surface of the head attached to the tip of the golf club shaft is a predetermined positional relationship with respect to the joint of the fiber reinforced synthetic resin sheet wound around the outermost side. A method for manufacturing a golf club.

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