JP6623554B2 - Golf club - Google Patents

Description

  The present invention relates to a golf club having a grip.

  A golf club is equipped with a grip.

  Usually, a plurality of recesses are formed on the surface of the grip. A typical example of this depression is a groove. Multiple grooves can contribute to slippage.

  In JP-A-2015-29744, a first area and a second area are defined, and the dent occupancy of the first area is smaller than that of the second area. With this setting, abrasion resistance and slip resistance can be obtained.

JP 2015-29744 A

  Particularly with a lightweight grip, durability tends to decrease. A durable, lightweight and non-slip grip is preferred.

  An object of the present invention is to provide a golf club having a grip that is excellent in durability and slip resistance.

  A preferred golf club has a head, a shaft and a grip. The grip has a grip surface. The gripping surface has a front end and a rear end. In this grip, in the circumferential direction, the gripping surface is divided into a front half-periphery and a back half-periphery. In this grip, in the axial direction, the gripping surface is partitioned into a specific axial direction portion whose distance from the rear end is 50% or more and 70% or less of the entire length. The area that is the front half-peripheral part and that is the specific axial direction part is a specific front area. In this grip, the specific front side section has a specific recess having a ratio X / Y of the axial length X to the circumferential length Y of 1 or more and 3 or less. The dent occupancy in the specific front side area is 3% or more and 20% or less. The weight of the grip is 45 g or less.

  Preferably, the contour line of the specific depression is a line having a radius of curvature of 0.2 mm or more.

  Preferably, the depth of the specific recess is 0.2 mm or more and 0.4 mm or less.

  Preferably, the grip portion has a first layer that is a surface layer and a second layer located inside the first layer, and the foaming rate of the first layer is smaller than the foaming rate of the second layer. .

  Preferably, the surface of the grip portion is formed of foamed rubber.

  A golf club having a grip excellent in durability and slip resistance can be obtained.

FIG. 1 is an overall view of a golf club according to an embodiment of the present invention. In FIG. 1, the illustration of the dent formed on the grip surface is omitted. FIG. 2 is an enlarged view of the vicinity of the grip in the golf club of FIG. Also in FIG. 2, the illustration of the dent formed on the grip surface is omitted. FIG. 3 is a sectional view taken along line F3-F3 in FIG. Also in FIG. 3, the illustration of the dent formed on the grip surface is omitted. FIG. 4 is an exploded view showing a recess pattern on the front side (half side of the front side) of the grip. In this developed view, the front half-circumferential portion is developed in a plane. FIG. 5 is a developed view showing a recess pattern on the front side (front side half circumference) of the grip according to another embodiment. In this developed view, the front half-circumferential portion is developed in a plane.

  Hereinafter, the present invention will be described in detail based on preferred embodiments with reference to the drawings as appropriate.

  In the present application, “axial direction” means the axial direction of the shaft unless otherwise specified. Unless otherwise specified, the term “circumferential direction” in the present application means the circumferential direction of the shaft.

  FIG. 1 is an overall view of a golf club 2 according to one embodiment of the present invention. The golf club 2 has a head 4, a shaft 6, and a grip 8. The head 4 is attached to one end of a shaft 6. The grip 8 is attached to the other end of the shaft 6.

  Examples of the head 4 include a wood type head, a utility type head, a hybrid type head, an iron type head, and a putter head. In the present embodiment, the head 4 is a wood type. Examples of the shaft 6 include a steel shaft and a carbon shaft. In the present embodiment, the shaft 6 is a carbon shaft. This shaft 6 is formed of laminated prepregs. Preferred clubs are wood type golf clubs, utility type golf clubs, hybrid type golf clubs and iron type golf clubs.

  FIG. 2 is an enlarged view of the vicinity of the grip 8 in the club 2. The grip 8 has a grip surface 8h. The grip surface 8h is a surface that can be gripped by a golfer. The grip surface 8h is an outer peripheral surface of the grip 8. Although not shown in FIG. 2, a large number of depressions are formed in the grip surface 8h. 1 and 2, illustration of these recesses is omitted.

  The inside of the shaft 6 is hollow. The shaft 6 is tubular. The grip 8 is substantially cylindrical. The grip surface 8h is a substantially circumferential surface as a whole.

  As shown in FIG. 2, the grip surface 8h has a front end Tp and a rear end Bt. The grip end of the grip 8 forms a convex curved surface. This convex curved surface is not included in the grip surface 8h.

  FIG. 3 is a sectional view taken along line F3-F3 in FIG. As shown in FIG. 3, the grip 8 has a back line BL. In the grip surface 8h, the back line BL forms a portion protruding from the circumferential surface. In the grip 8 before the shaft 6 is inserted, the outer surface of the grip 8 is a circumferential surface. On the other hand, in the grip 8 before the shaft 6 is inserted, a flat portion is formed on the inner surface of the grip 8. This flat portion forms a thick portion that is thicker than other portions. By inserting the shaft 6, this thick portion becomes the back line BL.

  This back line BL extends parallel to the axial direction. In the circumferential direction of the grip 8, the grip thickness at the back line BL is larger than the grip thickness at the portion without the back line BL. This back line BL is well known to those skilled in the art. As shown in FIG. 3, the back line BL rises outward. Due to the back line BL, the cross section line D8 of the gripping surface 8h after the shaft 6 is inserted is not a perfect circle (see FIG. 3).

  The grip 8 may not have the back line BL. In this case, the grip thickness is usually constant in the circumferential direction. In this case, the section line D8 is circular if the above-mentioned dent is ignored. The section line D8 is an intersection line between a plane perpendicular to the shaft axis Z1 and the grip surface 8h (see FIG. 3).

  In FIG. 2, what is indicated by a double-headed arrow L is the entire length of the gripping surface 8h. This total length L is measured along the axial direction. Considering the dimensions of the palm, the total length L is preferably 210 mm or more, more preferably 230 mm or more, and even more preferably 250 mm or more. In light of weight reduction, the total length L is preferably equal to or less than 300 mm, and more preferably equal to or less than 280 mm.

[Axial position P1, P2]
The axial position P1 is a position separated by 0.5 L in the axial direction from the rear end Bt. In other words, the axial distance between the position P1 and the rear end Bt is 0.5L (50% of the total length L). The axial position P2 is a position separated by 0.7 L in the axial direction from the rear end Bt. In other words, the axial distance between the position P2 and the rear end Bt is 0.7L (70% of the total length L).

[Specific axis direction part]
A portion having a distance from the rear end Bt of 50% or more and 70% or less of the entire length L is defined as the specific axial portion 8x. In other words, the axial range from the position P1 to the position P2 is the specific axial portion 8x.

[Front half circumference, back half circumference]
FIG. 3 shows the circumferential front reference position CF1. In the determination of the circumferential front reference position CF1, the golf club 2 is left stationary in the reference state. The reference state is a state in which the golf club 2 is left standing on the horizontal plane HP at a specified real loft angle and a lie angle. In this reference state, the shaft axis Z1 is included in a plane VP perpendicular to the horizontal plane HP. There are two intersections between the plane VP and the grip surface 8h in the circumferential direction. The upper side of these two circumferential positions is the circumferential front reference position CF1. A 180-degree range in the circumferential direction around the circumferential front reference position CF1 is the front half-circumferential portion 8f. The circumferential range other than the front half-circumferential portion 8f is the rear half-circumferential portion 8b.

  At the address, the golfer sees the front half-circumferential portion 8f. The right hand thumb of the right-handed golfer is in contact with the front half-circumferential portion 8f. During the swing, a force is particularly easily applied between the right thumb and the grip 8.

  FIG. 2 is a diagram of the holding surface 8h as viewed from the front side. Therefore, what is shown in FIG. 2 is the front half-circumferential portion 8f. FIG. 2 does not show the rear half-circumferential portion 8b.

  As shown in FIG. 3, a position 90 degrees away from the position CF1 on one side in the circumferential direction is CF2, and a position 90 degrees away from the position CF1 on the other side in the circumferential direction is CF3. The position CF2 is a boundary between the front half-periphery 8f and the back half-periphery 8b. The position CF3 is a boundary between the front half-periphery 8f and the back half-periphery 8b.

  As shown in FIG. 3, the circumferential center position BL1 of the back line BL is the circumferential center of the rear half-circumferential portion 8b.

  Typically, in the grip formed by the upper die and the lower die, the front half-periphery 8f is formed by one of the upper die and the lower die, and the back half-periphery 8b is formed by the other of the upper die and the lower die. In this case, a joint due to the parting line is formed at the boundary between the front half-circumferential portion 8f and the rear half-circumferential portion 8b.

[Specific front side area]
The area that is the front half-circumference portion 8f and the specific axial direction portion 8x is the specific front area 8t. In FIG. 2, the specific front side area 8t is indicated by two-dot chain line hatching. As described later, a strong force acts on the specific front side area 8t.

  FIG. 4 is a development view showing a number of depressions located on the front side of the grip 8. In other words, FIG. 4 is a development view of the front half-circumferential portion 8f.

  As shown in FIG. 4, the grip surface 8h (the front half-circumferential portion 8f) has a plurality of recesses r1. A plurality of dents are provided on the surface of the gripping surface 8h. For example, the recess r1 may be a groove. For example, the depression r1 may be in a point shape.

[Specific dent]
As shown in FIG. 4, the gripping surface 8h has a plurality (many) of specific recesses r2. Among the dents r1, one that satisfies the following (a) is the specific dent r2.
(A) When the axial length of the recess is X (mm) and the circumferential length of the recess is Y (mm), the ratio (X / Y) is 1 or more and 3 or less.

  The axial length X and the circumferential length Y are shown in the enlarged portion of FIG.

From the viewpoints of durability and difficulty in sliding, the specific dent r2 preferably satisfies the following (b).
(B) The maximum transverse length is 5 mm or less.
Note that the maximum traverse length is the length of the longest line segment among the line segments traversing the recess r1.

  The specific front side area 8t has a plurality (many) of specific dents r2. In the present embodiment, all of the depressions r1 provided in the specific front side area 8t are the specific depressions r2. The specific front side area 8t may have a dent r1 that is not the specific dent r2.

[Dent occupancy]
The dent occupancy is defined in the specific front side area 8t. This dent occupancy is the proportion of the area of the dent in the entire area of the specific front side area 8t. Assuming that the entire area of the specific front side area 8t is A1 and the total area of the dents is A2, the dent occupancy (%) is (A2 / A1) × 100. When a dent r1 other than the specific dent r2 exists in the specific front side area 8t, the area of the dent r1 is also added to the area A2.

  The areas A1 and A2 can be easily measured in a developed view as shown in FIG. In some cases, the grip surface has a non-developable surface (non-developable surface). For this non-developable surface, the areas A1 and A2 can be calculated using integration in the axial direction. In this integration, the area A1 is calculated based on a virtual straight line closing the opening of the dent.

[effect]
In a right-handed golfer, the right thumb contacts the specific front side area 8t. The right thumb supports the club 2 during the swing, especially in the top of swing. A strong force acts on the specific front side area 8t. In the specific front side section 8t where a large force is applied, it is effective that the slip resistance and durability are achieved. In the case of a left-handed golfer, the left thumb abuts the specific front area 8t, and the left thumb applies a large force to the specific front area 8t. In any case, a large force acts on the specific front side area 8t during the swing.

  On the other hand, with a lightweight grip, the rigidity and strength of the material are low. Therefore, abrasion and tearing are likely to occur due to a large force acting on the specific front side area 8t.

  The specific dent r2 can solve this problem. The skin of the finger enters the specific recess r2, and the grip surface fits the finger. For this reason, slippage is achieved without applying force.

  When an elongated groove-shaped depression is provided, the peripheral portion of the depression is likely to fall or be turned up by a strong force. That is, when the above X / Y is large, the peripheral portion of the dent tends to fall down or turn over. By setting X / Y to 3 or less, the peripheral portion of the dent is less likely to fall. For this reason, slippage does not easily occur, and tearing and wear are suppressed. In this respect, X / Y is more preferably equal to or less than 2. X / Y is preferably 1 or more from the viewpoint of suppressing the slip in the circumferential direction.

  Further, in the grip 8, the dent occupancy in the specific front side area 8t is set to 20% or less. By reducing the occupancy of the dent and increasing the area of the land, the peripheral portion of the dent is less likely to fall. For this reason, slippage does not easily occur, and tearing and wear are suppressed. In this respect, the dent occupancy is preferably equal to or less than 20%, more preferably equal to or less than 15%, and still more preferably equal to or less than 10%. From the viewpoint of difficulty in sliding, the dent occupancy is preferably 3% or more, more preferably 4% or more, and even more preferably 5% or more.

  Note that the land means a portion where the recess r1 is not provided.

  By providing the small specific dent r2 at an appropriate density, the fit to the finger is increased while the occupancy of the dent is suppressed. From the viewpoint of securing land around the specific dent r2, it is preferable that the distance between the specific dents r2 adjacent to each other is 2 mm or more. From the viewpoint of increasing the probability that the specific dent r2 hits the finger, it is not preferable that the specific dents r2 are excessively separated from each other. From this viewpoint, in the specific front side section 8t, the distance between the specific dents r2 adjacent to each other is preferably 10 mm or less.

  By providing a large number of small specific dents r2, it is possible to improve the fit to the finger while suppressing the occupancy of the dents. In this respect, the number of the specific recesses r2 in the specific front side section 8t is preferably equal to or greater than 30, more preferably equal to or greater than 40, and still more preferably equal to or greater than 50. In light of suppressing the dent occupancy, the number of the specific dents r2 in the specific front side section 8t is preferably equal to or less than 100, more preferably equal to or less than 90, and still more preferably equal to or less than 80.

By providing a large number of small specific dents r2, it is possible to improve the fit to the finger while suppressing the occupancy of the dents. From this viewpoint, an area of one particular recess r2 is preferably 19.6 mm ² or less, more preferably 12.6 mm ² or less, 7.1 mm ² or less being more preferred. From the viewpoint of sliding difficulty, the area of one particular recess r2 is preferably 0.1 mm ² or more, more preferably 0.3 mm ² or more, 0.5 mm ² or more is more preferable. It is more effective if all the specific dents r2 present in the specific front side area 8t are the above-mentioned preferable areas. This area means the area inside the contour of the specific dent r2.

  As shown by the enlarged portion in FIG. 4, the contour of the specific dent r2 is constituted by a line having a radius of curvature of 0.2 mm or more. In other words, the contour has no portion with a radius of curvature of less than 0.2 mm. Therefore, the stress is dispersed, and the tearing is suppressed. Lines having a radius of curvature of 0.2 mm or more include straight lines in addition to curves. The radius of curvature is determined in a plan view as shown in a development view of FIG.

  The specific recess r2 shown in the enlarged portion of FIG. 4 is a triangle. That is, the contour of the specific dent r2 has a shape having corners. From the viewpoint of dispersing the stress, the radius of curvature R of the corner is preferably 0.2 mm or more. From the viewpoint of miniaturization of the specific recess r2, the radius of curvature R of this corner is preferably 5 mm or less.

  Preferably, the depth of the specific recess r2 is 0.4 mm or less. By reducing the depth, the peripheral portion of the dent is less likely to fall. For this reason, slippage does not easily occur, and tearing and wear are suppressed. From the viewpoint of difficulty in sliding, the depth of the specific recess r2 is preferably 0.2 mm or more.

  The grip 8 has a structure of a plurality of layers. The enlarged view of FIG. 3 shows a cross section of the grip 8 (grip surface 8h). As shown in this enlarged view, the gripping surface 8h has a first layer s1 that is a surface layer, and a second layer s2 that is located inside the first layer s1. Further, the gripping surface 8h has a third layer s3 located inside the second layer s2. The second layer s2 is in contact with the inner surface of the first layer s1. The third layer s3 is in contact with the inner surface of the second layer s2. The first layer s1 is the outermost layer. The third layer s3 is the innermost layer.

  Foam rubber is used for the grip 8. The foaming rate of the first layer s1 is smaller than the foaming rate of the second layer s2. Furthermore, the foaming rate of the second layer s2 is smaller than the foaming rate of the third layer s3. The outer layer has a lower foaming rate. The foaming rate of the first layer s1, which is the outermost layer, is zero or low. Therefore, the rigidity and strength of the surface layer are increased while the weight of the grip 8 is reduced. As a result, the fall of the peripheral portion of the specific dent r2 is suppressed. Due to the synergistic effect of the suppression of falling and the strength of the material, tearing and wear are suppressed.

  The manufacturing method for making the foaming ratio different includes, for example, preparing a first sheet constituting the first layer s1, a second sheet constituting the second layer s2, and a third sheet constituting the third layer s3. Is done. A laminate in which these sheets are laminated is set in a mold. By separately preparing the first sheet, the second sheet, and the third sheet, the foaming rates of the respective sheets can be different from each other.

  The surface of the grip surface 8a may be formed of foamed rubber. Foam rubber has low strength and rigidity. Therefore, from the viewpoint of the material, the above-mentioned falling easily occurs and the durability is low. The disadvantage of this material is suppressed by the above-mentioned specific dent r2. Therefore, even if the surface is foamed rubber, a grip excellent in slippage and durability can be obtained.

  FIG. 5 is a developed view showing the front half-circumferential portion 8f of the grip according to the second embodiment. The front half-circumferential portion 8f has a large number of depressions r1, and these depressions r1 include a large number of specific depressions r2.

  The specific front side area 8t is provided with a plurality (many) of specific dents r2. All of the depressions r1 provided in the specific front side area 8t are the specific depressions r2. As shown in FIG. 5, two types of specific recesses r2 are provided in the specific front side area 8t. The first type specific dent r2 is elliptical, and the second type specific dent r2 is circular. Thus, a plurality of types of specific dents r2 may be provided in the specific front side area 8t.

  The area that is the rear half-circumferential part 8b and is the specific axial direction part 8x is referred to as a specific rear area. Although not shown, the specific back area has a number of depressions r1. Although not shown, all the dents r1 provided in the specific back area are the specific dents r2. When a large force acts on the specific front area 8t, a relatively large force tends to act on the specific back area. In the case of a right-handed golfer, typically, the right thumb applies a large force to the specific front area 8t, and the right index finger receives this force in the specific back area. Therefore, it is preferable that the specific dent r2 is also provided in the specific back side area with the same specification as the specific front side area 8t. From this point of view, any description of the specific front side area 8t in the present application can also be applied to the specific back side area. For example, the dent occupancy in the specific back side area is preferably 3% or more, and more preferably 20% or less.

  As described above, in the lightweight grip, the effect of the specific dent r2 stands out. In this respect, the weight of the grip is preferably equal to or less than 45 g, more preferably equal to or less than 35 g, and still more preferably equal to or less than 30 g. If the grip is excessively light, an uncomfortable feeling may occur when swinging. In this respect, the weight of the grip is preferably 15 g or more, more preferably 20 g or more, and even more preferably 25 g or more.

  The weight of the grip can be adjusted by the specific gravity, volume, etc. of the grip. Foam rubber may be used for the lightweight grip. Foam rubber is rubber containing air bubbles. The specific gravity can be adjusted by, for example, the foaming ratio. The foaming ratio can be calculated based on the area of bubbles in a cross section. The ratio of the total area of the bubbles to the area of the entire cross section is the foaming ratio. In the measurement of the foaming ratio, cross sections are observed at three positions, the position P1, the position P2, and the third position P3. This position P3 is a position that equally divides the position P1 and the position P2, and is a position 0.6 L from the rear end. The calculated values at these three cross sections are averaged. This average value can be taken as the foaming ratio.

  The paint may be arranged inside the specific recess r2. With this paint, for example, a specific specific dent r2 can be visually conspicuous.

  The material of the grip 8 is not limited. Examples of the material of the grip 8 include a rubber composition and a resin composition. Examples of the rubber in the rubber composition include natural rubber (NR), ethylene propylene diene rubber (EPDM), styrene butadiene rubber (SBR), isoprene rubber (IR), butadiene rubber (BR), chloroprene rubber (CR), Acrylonitrile butadiene rubber (NBR) and the like. In particular, a material obtained by blending (mixing) natural rubber or ethylene propylene diene rubber or styrene butadiene rubber having a good affinity for natural rubber is preferable.

  Oil may be blended in the rubber composition. As the oil, for example, an aromatic oil, a naphthenic oil, a paraffin oil, or the like can be used.

  If sulfur crosslinking is to be provided, sulfur is incorporated.

  For example, a reinforcing agent, a filler, a vulcanization accelerator, a vulcanization aid, and the like may be appropriately compounded in the rubber composition as needed. Further, an antioxidant, a processing aid and the like may be blended.

  As the reinforcing agent, for example, carbon, silica and the like can be used. As the filler, for example, hard clay, calcium carbonate, magnesium carbonate, clay and the like are used, and as the vulcanization aid, for example, zinc oxide and stearic acid are used. The vulcanization accelerator can be appropriately selected according to the rubber to be used, according to a known method.

  As a material of the grip, a resin composition may be used. As a resin contained in the resin composition, a thermoplastic resin is exemplified. This thermoplastic resin can be used for injection molding. As the thermoplastic resin, a thermoplastic elastomer is preferable, and a thermoplastic elastomer containing a soft segment and a hard segment is more preferable. A urethane-based thermoplastic elastomer is more preferable from the viewpoint of achieving both grip properties and wear resistance.

  The preferable compounding ratio with respect to 100 parts by mass of rubber is, for example, 5 to 70 parts by mass of a reinforcing agent, 10 to 70 parts by mass of a filler, 0.1 to 3 parts by mass of a vulcanization accelerator, and 1 to 1 part of a vulcanization aid. 10 parts by mass.

  A coloring agent may be blended. This colorant can impart a color other than black to the grip 8. Typical colorants are pigments. Examples of the pigment include an organic pigment and an inorganic pigment. Examples of the organic pigment include an azo pigment, a phthalocyanine pigment, a quinacridone pigment, and a dyed lake pigment. As the inorganic pigment, a composite oxide pigment is exemplified. Note that carbon black is not a coloring agent.

  The proportion of the rubber component can be reduced by adding the coloring agent. The proportion of the reinforcing agent can be reduced by adding the coloring agent. The abrasion resistance of the grip 8 tends to be reduced due to the blending of the coloring agent. Therefore, in the grip 8 in which the coloring agent is mixed, the effect of the specific dent r2 stands out.

  When the rubber composition is a foamed rubber, a foaming agent may be blended. One example of the foaming agent is a pyrolytic foaming agent. Examples of the thermal decomposition type foaming agent include an azo compound such as azodicarbonamide, a nitroso compound such as dinitrosopentamethylenetetramine, and a triazole compound.

  The manufacturing method of the grip 8 is not limited. The grip 8 can be manufactured by a known manufacturing method. As this manufacturing method, press molding and injection molding are exemplified.

  In press molding, a rubber composition is filled in a mold, and pressure and heat are applied. The heating temperature is usually 130 to 200 ° C., but is not limited to this. The heating time is usually 3 to 15 minutes, but is not limited thereto.

  The JIS-A hardness of the grip is preferably 30 or more, more preferably 35 or more, and particularly preferably 40 or more, from the viewpoint of suppressing excessive deformation of the grip, and particularly enhancing the grip property when dry. From the viewpoint of suppressing the feeling of grip from becoming excessively hard and increasing the gripping property when wet, the JIS-A hardness of the grip is preferably 70 or less, more preferably 60 or less, and particularly preferably 50 or less. This JIS-A hardness is measured in accordance with JIS-K-6253.

  Hereinafter, the effects of the present invention will be clarified by examples, but the present invention should not be construed as being limited based on the description of the examples.

[Example 1]
The grip shown in FIG. 4 was made. A mold having a mandrel, upper mold and lower mold was used. The inner surface (semi-peripheral surface) of the upper die had a projection for forming a recess in the front half-periphery 8f. A sheet for the first layer, a sheet for the second layer, and a sheet for the third layer were obtained using the three types of rubber compositions. These sheets were stacked and charged in the mold, and heated and pressed to obtain a grip molded body. This grip molded body had a three-layer structure. The foaming ratio of the third layer (the innermost layer) was higher than that of the second layer. The foaming ratio of the second layer was higher than that of the first layer.

  The surface of this grip molded body was polished to obtain the grip of Example 1. The front half-circumferential portion 8f of this grip had a number of depressions shown in FIG. The weight of the grip was 27 g. This grip was mounted on a commercially available golf club. As this golf club, a trade name “XXIO Eight Driver Loft 10.5 °” manufactured by Dunlop Sports Co., Ltd. was used. The golf club according to Example 1 was obtained by removing the standard grip and attaching the grip of Example 1.

[Comparative Example 1, Example 2, Example 3, Comparative Example 2]
A grip and a golf club according to Comparative Example 1, Example 2, Example 3, and Comparative Example 2 were obtained in the same manner as in Example 1, except that the number of the specific dents r2 was increased or decreased to change the dent occupancy.

[Comparative Example 3, Example 4, Example 5, Comparative Example 4]
A grip and a golf club according to Comparative Example 3, Example 4, Example 5, and Comparative Example 4 were obtained in the same manner as in Example 2 except that X / Y was changed by changing the shape of the specific recess r2. .

[Examples 6 to 9]
Grips and golf clubs according to Examples 6 to 9 were obtained in the same manner as in Example 4 except that the shape of the specific recess r2 was changed to change the radius of curvature of the corner.

[Examples 10 to 12]
The grips and golf clubs according to Examples 10 to 12 were obtained in the same manner as Example 4 except that the depth of the specific recess r2 was changed.

  The specifications and evaluation results of these examples and comparative examples are shown in Tables 1 to 4 below. In addition, in order to facilitate comparison in each table, Example 2 and Example 4 are described in a plurality of places.

  [Evaluation method]

[Wear test]
A wear test was performed using a Gakushin type friction tester (Gakushin type dyeing friction fastness tester manufactured by Yasuda Seiki Seisakusho Co., Ltd.). A test piece was obtained by cutting out a specific front side area of the grip. The test piece was adhered to the apparatus stand of the tester with a double-sided tape, and the surface of the test piece was reciprocated 500 times with sandpaper. The wear volume (cm ³ ) from this test is shown in Tables 1 to 4 above. The wear volume was calculated by dividing the wear weight by the specific gravity.

[Peeling test]
A peeling test was performed using the grip cap constituting the grip end. A grip was inserted into the shaft and a specific frontal area of the grip was rubbed with the grip cap. The grip cap was moved in a direction at 90 ° to the shaft axis and rubbed. The test was performed until the surface layer peeled off, with the upper limit being 500 times. Tables 1 to 4 show the number of times of rubbing when peeling occurred. However, when peeling did not occur at the upper limit of 500 times, the evaluation value was 500.

[Slip when hitting]
Twenty testers actually hit with the golf club, and performed a sensory evaluation on a 5-point scale from 1 point to 5 points. The most difficult case was scored 5 points, and the less slippery the higher the score. The average of the evaluation values of all testers (rounded off to the decimal point) is shown in Tables 1 to 4 above.

  From these evaluation results, the superiority of the present invention is clear.

  The present invention can be applied to any golf club.

2 ... Golf club 4 ... Head 6 ... Shaft 8 ... Grip 8h ... Grip surface 8f ... Front half circumference 8b ... Back half circumference 8x ... Specific axial direction part 8t ... Specific front side area L ... Length of gripping surface Z1 ... Shaft axis r1 ... Dent r2 ... Specific dent P1 ... Distance from rear end of gripping surface is 50 of total length of gripping surface % Position P2: Position where the distance from the rear end of the gripping surface is 70% of the entire length of the gripping surface CF1 ... Circumferential front reference position BL ... Backline

Claims (1)

It has a head, shaft and grip,
The grip has a gripping surface,
The gripping surface has a front end and a rear end,
In the circumferential direction, the gripping surface is divided into a front half circumference and a back half circumference,
In the axial direction, the gripping surface is partitioned into a specific axial direction portion whose distance from the rear end is 50% or more and 70% or less of the entire length,
When the area that is the front half-peripheral part and is the specific axial direction part is a specific front area,
The specific front side area has a specific dent in which the ratio X / Y between the axial length X and the circumferential length Y is 1 or more and 3 or less,
The dent occupancy in the specific front side area is 3% or more and 20% or less,
The weight of the grip is 45 g or less,
The grip portion forming the grip surface has a first layer that is a surface layer, a second layer located inside the first layer , and a third layer located inside the second layer , the expansion ratio of the first layer is rather smaller than the expansion ratio of the second layer, the foaming rate of the second layer is smaller than the expansion ratio of the third layer,
The depth of the specific dent is 0.2 mm or more and 0.4 mm or less,
The gripping surface is formed of foam rubber,
A golf club wherein the contour of the specific dent has a shape having a corner, and a radius of curvature of the corner is 0.2 mm or more and 5 mm or less .

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