JP7577968B2 - Golf Clubs - Google Patents

Description

The present invention relates to a golf club.

Conventionally, various golf club heads have been proposed to increase the flight distance of a hit ball. For example, the following Patent Document 1 describes optimizing the rigidity of the crown part of a golf club head. Such a golf club head is expected to reduce energy loss when hitting a ball, and thus increase the flight distance of the hit ball.

JP 2005-137788 A

The inventors attempted to reduce energy loss when hitting a ball by taking a different approach, focusing on the deformation behavior of the shaft when hitting a ball.

A detailed analysis of the deformation behavior of the shaft during a swing revealed that when the ball is hit, a phenomenon called "rebound" occurs, in which the shaft near the golf club head is locally pushed back toward the rear of the head. It was also found that the greater the shaft's rebound, the greater the energy loss when hitting the ball.

The present invention was devised in consideration of the above-mentioned circumstances, and its main objective is to provide a golf club that reduces energy loss when hitting a ball and, in turn, increases the flight distance of the ball.

The first aspect of the present invention is a golf club that includes a golf club head having a shaft, a neck portion into which the shaft is inserted, and a support portion that protrudes from the neck portion toward the rear of the head.

The second aspect of the present invention is a golf club that includes a shaft, a golf club head having a neck portion into which the shaft is inserted, a ferrule attached to the neck portion, and a support portion protruding from the ferrule above the head on the rear side of the head.

In each of the above embodiments, the support portion can have a height of 5 mm or more along the axial direction of the shaft.

In each of the above aspects, the support portion may be curved along the outer surface of the shaft.

In each of the above embodiments, when the golf club is in a stationary state, the support portion may be spaced apart from the shaft.

In each of the above aspects, the support portion may be formed within a range of 30° or more around the center line of the shaft in a cross section perpendicular to the axial direction of the shaft.

The third aspect of the present invention is a golf club including a shaft, a golf club head having a neck portion into which the shaft is inserted, and a ferrule attached to the neck portion, the ferrule including a front portion located on the front side of the head and a rear portion located on the rear side of the head, the rigidity of the rear portion being greater than the rigidity of the front portion.

In the third aspect, the thickness of the rear portion may be greater than the thickness of the front portion.

In the third aspect, the Young's modulus of the rear portion may be greater than the Young's modulus of the front portion.

A fourth aspect of the present invention is a golf club that includes a shaft having a hollow portion therein, a golf club head having a neck portion into which the shaft is inserted, and a dilatant fluid disposed near the neck portion of the hollow portion.

In the fourth aspect, the dilatant fluid may be disposed in the hollow portion while being sealed in a flexible bag.

In the fourth aspect, the dilatant fluid may be disposed in at least a portion of a range of 100 mm above the upper end of the neck portion in the axial direction of the shaft.

The golf club of each of the above aspects of the present invention employs the above-mentioned configuration, and thus the bending back is reduced by the support part, the rear part of the ferrule, or the dilatant fluid. Therefore, the golf club of each of the above aspects of the present invention can reduce energy loss when hitting the ball, and ultimately increase the flight distance of the ball.

FIG. 2 is a partial perspective view of the golf club according to the first embodiment. FIG. 2 is a front view of the golf club of FIG. 1 . FIG. 2 is a side view of the golf club of FIG. 1 as viewed from the toe side. 1 is a conceptual diagram showing the behavior of a golf club when it is swung. 3 is a cross-sectional view taken along line VV in FIG. 2. 6 is a cross-sectional view taken along line VI-VI in FIG. FIG. 11 is a partial perspective view of a golf club according to a second embodiment. FIG. 8 is a front view of the golf club of FIG. 7. FIG. 8 is a side view of the golf club of FIG. 7 as viewed from the toe side. 9 is a cross-sectional view taken along line XX in FIG. 8. 11A is a perspective view of a ferrule according to a third embodiment, and FIG. 11B is a partial cross-sectional view of a golf club equipped with the ferrule. FIG. 10 is a partial perspective view of a golf club according to a fourth embodiment. FIG. 13 is a side view of the golf club of FIG. 12 as viewed from the toe side. 14 is a partial cross-sectional view of the golf club including the axial centerline of the shaft of FIG. 13.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
In this specification, the same or common elements are given the same symbols and duplicated explanations are omitted.

[First embodiment]
1 to 3 are respectively a partial perspective view, a front view, and a side view seen from the toe side of a golf club 1 according to a first embodiment. As shown in Figs. 1 to 3, the golf club 1 according to the present embodiment includes a shaft 2, a golf club head 3, and a support portion 4.

[Reference conditions, etc.]
1 to 3, the golf club 1 is in a reference state. The reference state of the golf club 1 is a state in which the golf club 1 is placed on a horizontal plane HP with a lie angle α (FIG. 2) and a loft angle β (FIG. 2) determined for the golf club 1. Also, as shown in FIG. 3, in the reference state, the golf club 1 is held at a lie angle α and a loft angle β with the axial center line CL of the shaft 2 of the golf club 1 being disposed in a reference vertical plane VP perpendicular to the horizontal plane HP. Unless otherwise specified in this specification, the golf club 1 is described as being in the reference state.

In the reference state of the golf club 1, the direction x perpendicular to the reference vertical plane VP is defined as the head front-to-rear direction, with the side of the face 31 being the front side (forward) and the opposite side being the rear side (rear). In addition, the direction y parallel to both the reference vertical plane VP and the horizontal plane HP is defined as the toe-heel direction. Furthermore, the direction z perpendicular to the horizontal plane HP is defined as the head up-down direction.

[shaft]
A golf club head 3 is attached to the tip side of the shaft 2. For example, a grip (not shown) is attached to the rear end side of the shaft 2. The shaft 2 in this embodiment is configured as a pipe with a circular cross section having a hollow portion inside. The shaft 2 is made of, for example, steel, fiber-reinforced resin, or the like according to convention. The direction along the axial center line CL of the shaft 2 is defined as the axial direction of the shaft 2.

[Golf club head]
The golf club head 3 of this embodiment is configured as, for example, a wood-type golf club head with a hollow interior. The golf club head 3 is, for example, entirely made of a metal material, but a part of it may be made of fiber-reinforced resin or the like. In other embodiments, the golf club head 3 may be configured as an iron type, a utility type, or a putter type.

The golf club head 3 includes, for example, a face portion 31, a crown portion 32, a sole portion 33, and a neck portion 34.

The face portion 31 is formed on the front side of the golf club head 3 and constitutes the striking surface that strikes the ball. The crown portion 32 extends from the face portion 31 to the rear of the head to form the top surface of the head. The sole portion 33 extends from the face portion 31 to the rear of the head to form the bottom surface of the head.

The neck portion 34 is formed on the heel side of the crown portion 32. The neck portion 34 protrudes obliquely from the crown portion 32 toward the top of the head and terminates at an upper end surface 34a. The neck portion 34 is cylindrical and has a shaft insertion hole 35 (FIG. 3) for inserting the shaft 2. The shaft 2 is fixed to the shaft insertion hole 35 using an adhesive. In this embodiment, the neck portion 34 is made of a metal material and is formed integrally with the other parts of the golf club head 3.

[Support part]
In this embodiment, the support portion 4 is provided on the neck portion 34. The support portion 4 protrudes upward from the neck portion 34 on the head rear side of the neck portion 34. The support portion 4 in this embodiment is integrally molded with the neck portion 34. Therefore, the support portion 4 in this embodiment is made of a metal material. In a preferred embodiment, the support portion 4 is formed as an extension portion 41 that locally extends the head rear side of the neck portion 34 upward. In another embodiment, the support portion 4 may be a separate part from the neck portion 34 and attached to the neck portion 34 by screws, adhesives, welding, or the like.

The support portion 4 suppresses what is called "rebound" when the golf club 1 hits the ball. Here, a general explanation of "rebound" will be given. FIG. 4 is a conceptual diagram showing the behavior of the shaft when golf club a is swung, to explain rebound. As shown in FIG. 4, during the swing process of golf club a, until just before hitting ball b, shaft c of golf club a is in an overall bent state so that it is almost convex toward the rear of the head. However, when golf club head d hits ball b, the impact force causes the golf club head d side of shaft c to bend so that it is pushed back locally toward the rear of the head. This is "rebound".

When rebound occurs, the kinetic energy of the golf club head d is not fully transmitted to the ball b (energy loss). In particular, the lower the impact point between the ball b and the face e, the greater the rebound, and as a result, the ball b is launched lower and the amount of backspin increases due to the gear effect. This type of trajectory reduces the flight distance.

As is clear from FIG. 3, the support portion 4 of this embodiment contacts the rear side of the head of the shaft 2 in the early stages of the occurrence of the return to bending, and prevents the shaft 2 from bending toward the rear of the head near the neck portion 34, thereby preventing the return of the shaft 2. Therefore, the golf club 1 of this embodiment reduces energy loss when hitting the ball, and thus increases the flight distance of the ball.

[Support height]
Figure 5 is a cross-sectional view taken along line V-V in Figure 2. As shown in Figure 5, the support portion 4 may have a height L along the axial direction of the shaft 2 of, for example, 5 mm or more, preferably 8 mm or more, and more preferably 10 mm or more. This height L is the length along the axial direction of the shaft 2 from the upper end surface 34a of the neck portion 34 to the upper end surface 4a of the support portion 4. The support portion 4 having such a height L can more effectively suppress the bending back of the shaft 2 when hitting a ball.

If the height L of the support portion 4 is excessively large, the head weight will increase and the flex characteristics of the shaft 2 may deteriorate. From this perspective, the height L of the support portion 4 may be, for example, 100 mm or less, more preferably 70 mm or less, and even more preferably 50 mm or less.

[Fixation between support part and shaft]
It is preferable that the support portion 4 and the shaft 2 are not fixed to each other. This allows the tip side (neck portion 34 side) of the shaft 2 to bend toward the front of the head during the downswing without being restrained by the support portion 4. This helps to suppress a decrease in head speed.

[Gap between support and shaft]
5, when the golf club 1 is in a stationary state (i.e., when it is not being swung, the same applies below), it is desirable that the support portion 4 is separated from the shaft 2. Such a support portion 4 does not come into contact with the shaft 2, or can significantly reduce the chance of contact, until the moment the ball is struck. This ensures free bending of the shaft 2 during the swing, and suppresses deterioration of the swing feeling.

The gap G between the support part 4 and the shaft 2 can be set as appropriate. For example, from the viewpoint of further reducing the chance of contact between the support part 4 and the shaft 2 until the ball is hit, the gap G may be set to, for example, 0.3 mm or more, preferably 0.5 mm or more, and more preferably 1 mm or more. On the other hand, from the viewpoint of further reducing the bending back of the shaft 2, the gap G may be set to, for example, 2.0 mm or less, more preferably 1.8 mm or less, and more preferably 1.5 mm or less.

[Shape of support part, etc.]
Figure 6 is a cross-sectional view taken along line VI-VI in Figure 1 (a cross-section perpendicular to the axial direction of shaft 2). As shown in Figure 6, it is preferable that support portion 4 is curved in an arc shape along the outer surface of shaft 2. In this embodiment, a large contact area between support portion 4 and shaft 2 can be obtained when restraining return of shaft 2, and the occurrence of large local stress in shaft 2 can be suppressed.

As shown in Figure 6, it is desirable that the support portion 4 is formed in a range θ of, for example, 30° or more, preferably 45° or more, and more preferably 60° or more around the axial center line CL of the shaft 2 in a cross section perpendicular to the axial direction of the shaft 2. Even in this embodiment, a large contact area between the support portion 4 and the shaft 2 is obtained, and the bending back of the shaft 2 can be suppressed while suppressing the occurrence of large localized stress in the shaft 2.

On the other hand, if the range θ of the support part 4 becomes large, the support part 4 and the shaft 2 may come into contact during the downswing, which may limit the inherent flexure of the shaft 2. From this perspective, the range θ in which the support part 4 is formed may be, for example, 180° or less, preferably 160° or less, and more preferably 140° or less.

In FIG. 6, it is preferable that the center line 4CL, which bisects the range θ extending from the axial center line CL of the shaft 2, coincides with the front-rear direction x of the head. This can reliably suppress bending back.

When hitting a ball, the shaft 2 bends back while twisting slightly clockwise in FIG. 6 due to the impact force received by the golf club head 3, so the center line 4CL of the support part 4 may be located on the heel side in the front-to-back direction x of the head. In this case, it is desirable for the center line 4CL to be at an angle of 15° or less with respect to the front-to-back direction x of the head.

[Second embodiment]
Next, a second embodiment of the present invention will be described. Figures 7 to 9 respectively show a perspective view, a front view, and a side view seen from the toe side of a golf club 1 of the second embodiment. As shown in Figures 7 to 9, the golf club 1 of the second embodiment includes a shaft 2, a golf club head 3 having a neck portion 34 into which the shaft 2 is inserted, a ferrule 5 attached to the neck portion 34, and a support portion 4 protruding from the ferrule 5 to above the head on the head rear side.

Figure 10 shows a cross-sectional view of line X-X in Figure 8. As shown in Figures 7 to 10, the ferrule 5 is a substantially cylindrical part having a hole through which the shaft 2 passes. The ferrule 5 of this embodiment has a ferrule body 51 that extends upward from the neck portion 34 in a tapered shape. The ferrule 5 of this embodiment also has a socket portion 52 that extends downward from the ferrule body 51. The socket portion 52 is held between the neck portion 34 and the shaft 2. The ferrule 5 is made of, for example, a resin material. In another aspect, the ferrule 5 may be made of a metal material.

The support part 4 in this embodiment protrudes from the ferrule 5 above the head on the rear side of the head of the ferrule 5. The support part 4 in this embodiment is formed integrally with the ferrule 5. In a preferred embodiment, the support part 4 in this embodiment is formed as an extension part 42 that locally extends the rear side of the head of the ferrule 5 upward. In another embodiment, the support part 4 may be a separate part from the ferrule 5 and attached to the ferrule 5 by screws, adhesive, welding, etc.

The support portion 4 as described above contacts the rear side of the head of the shaft 2 at the initial stage of the occurrence of the return of the shaft when the golf club 1 strikes a ball, and prevents the shaft 2 located near the neck portion 34 from bending toward the rear of the head, thereby preventing the shaft 2 from returning to its original shape. Therefore, the golf club 1 of the second embodiment also reduces energy loss when striking a ball, and thus increases the flight distance of the ball.

In a preferred embodiment, the height L (FIG. 8) of the support part 4 along the axial direction of the shaft 2 can be set within the same range as the height L of the support part 4 described in the first embodiment.

In a preferred embodiment, it is desirable that the support portion 4 and the shaft 2 are not fixed to each other. This allows the tip side (neck portion 34 side) of the shaft 2 to bend toward the front of the head during the downswing without being restrained by the support portion 4. This helps to prevent a decrease in head speed.

In a preferred embodiment, as shown in FIG. 10, when the golf club 1 is in a stationary state (i.e., not being swung), the support portion 4 is desirably spaced apart from the shaft 2. In this case, the gap G between the support portion 4 and the shaft 2 can be set within the same range as the gap G of the support portion 4 described in the first embodiment.

In a preferred embodiment, the support portion 4 is curved in an arc along the outer surface of the shaft 2. In this embodiment, a large contact area between the support portion 4 and the shaft 2 can be obtained when preventing the shaft 2 from returning to its original shape, and the occurrence of large localized stresses in the shaft 2 can be prevented.

In a preferred embodiment, the formation range of the support portion 4 in a cross section perpendicular to the axial direction of the shaft 2 can be determined in the same manner as the range θ described in the first embodiment.

[Third embodiment]
Next, a third embodiment of the present invention will be described. Fig. 11(A) is a perspective view of a ferrule 5 of the third embodiment, and Fig. 11(B) is a partial cross-sectional view of a golf club 1 equipped with the ferrule 5. As shown in Figs. 11(A) and (B), the ferrule 5 includes a front side portion 5A located on the front side of the head and a rear side portion 5B located on the rear side of the head.

The front side portion 5A and the rear side portion 5B are fixed integrally to each other. In this embodiment, the front side portions 5A and 5B of the ferrule 5 each constitute half (180 degrees) of the circumference of the shaft 2, and the ferrule 5 as a whole continuously surrounds the shaft 2 in an annular shape. In this embodiment, the ferrule 5 is configured such that the rigidity of the rear side portion 5B is greater than the rigidity of the front side portion 5A.

The rear side 5B of the ferrule 5 as described above prevents the shaft 2 located near the neck portion 34 from bending toward the rear of the head when hitting the ball. Therefore, the rear side 5B of the ferrule 5 comes into contact with the rear side of the head of the shaft 2 at the initial stage of bending back when hitting the ball, preventing the shaft 2 located near the neck portion 34 from bending toward the rear of the head (arrow B in FIG. 11(B)), and preventing the shaft 2 from bending back. Therefore, the golf club 1 of this embodiment reduces energy loss when hitting the ball, and ultimately increases the flight distance of the ball.

The front portion 5A of the ferrule 5 is constructed with less rigidity than the rear portion 5B. Therefore, the ferrule 5 of this embodiment does not prevent the shaft 2 from bending forward of the head (arrow A in FIG. 11(B)) during a swing, and thus can suppress a decrease in head speed during a swing.

In the ferrule 5, in order to make the rigidity of the rear portion 5B greater than that of the front portion 5A, for example, the thickness tb of the rear portion 5B may be greater than the thickness ta of the front portion 5A. In this case, the front portion 5A and the rear portion 5B of the ferrule 5 may be formed of the same material. The difference (tb-ta) between the thickness tb of the rear portion 5B and the thickness ta of the front portion 5A is preferably 1 mm or more, more preferably 2 mm or more, and even more preferably 3 mm or more. The thicknesses ta and tb are measured on a straight line along the front-rear direction x of the head that passes through the axial center line CL of the shaft 2 at the upper end surface 5a of the ferrule 5 as shown in FIG. 11(A). This is because the thicknesses ta and tb of this portion are greatly involved in the resistance force when contacting the shaft 2.

In another embodiment, the Young's modulus of the rear portion 5B of the ferrule 5 may be greater than that of the front portion 5A. In this case, the front portion 5A and the rear portion 5B of the ferrule 5 are formed of different materials. For example, the front portion 5A of the ferrule 5 may be formed of a resin material, while the rear portion 5B of the ferrule 5 may be formed of a metal material. In order to more effectively suppress bending back, the Young's modulus of the rear portion 5B is, for example, 10 GPa or more, preferably 20 GPa or more, and more preferably 40 GPa or more.

In the third embodiment, the rear side portion 5B of the ferrule 5 also suppresses bending of the shaft 2 toward the rear of the head, but it is desirable not to prevent bending of the head toward the front. From this perspective, it is desirable that the rear side portion 5B of the ferrule 5 is not fixed to the shaft 2.

Similarly, when the golf club 1 is in a stationary state, it is desirable for the rear side 5B of the ferrule 5 to be separated from the shaft 2. This ensures that the rear side 5B of the ferrule 5 does not come into contact with the shaft 2, or significantly reduces the chance of contact, until the moment the ball is struck. This helps ensure free flexion of the shaft 2 during the swing and prevents the swing feeling from deteriorating.

As shown by the phantom lines in FIG. 11(B), the rear side portion 5B of the ferrule 5 may protrude higher than the front side portion 5A, as in the second embodiment. Such a ferrule 5 can suppress the return of the flex at an earlier stage when hitting the ball.

[Fourth embodiment]
Next, a fourth embodiment of the present invention will be described.
12 to 14 respectively show a perspective view, a side view, and a cross-sectional view including the axial center line of the shaft 2 of the golf club 1 of the fourth embodiment. As shown in Fig. 12 to 14, the golf club 1 is configured to include a pipe-shaped shaft 2 having a hollow portion i therein, a golf club head 3 having a neck portion 34 into which the shaft 2 is inserted, and a dilatant fluid 60 disposed near the neck portion 34 of the hollow portion i.

The dilatant fluid 60 can be prepared, for example, as a mixture of microparticles and water, and examples of the microparticles include potato starch and corn starch. In the former case, a mixture of 1 part potato starch and 1 part water is preferable. Such a dilatant fluid 60 has the property of behaving like a liquid when subjected to slow shear stimuli, while exhibiting resistance as if it were a solid when subjected to faster shear stimuli. In a particularly preferred embodiment, the dilatant fluid has a viscosity of 0.2 Pa·s at a relatively low shear rate of 2 s ^-1 and a viscosity of 3 Pa·s at a relatively high shear rate of 100 s ^-1 .

The operation of the fourth embodiment is as follows. The dilatant fluid 60 disposed in the shaft 2 exhibits almost no resistance to the relatively slow bending of the shaft 2 during a swing. Therefore, in this embodiment, the deterioration of the swing feeling of the golf club 1 and the decrease in head speed are suppressed. On the other hand, the dilatant fluid 60 exhibits a resistance force as if it were a solid to the high-speed bending of the shaft 2 when the golf club head 3 hits the ball, suppressing the bending back of the shaft 2. Therefore, the golf club 1 of the fourth embodiment reduces energy loss when hitting the ball, and thus increases the flight distance of the ball.

The dilatant fluid 60 is preferably fixed in the hollow portion i of the shaft 2, for example, sealed in a flexible bag 61. This embodiment allows the dilatant fluid 60 to be easily positioned at a predetermined location while maintaining the desired shape.

The bag 61 is preferably formed of a resin or elastomer, such as nylon or silicone. The bag 61 is arranged, for example, so as to contact the inner peripheral surface of the shaft 2. Therefore, when the shaft 2 deforms, the deformation is transmitted to the dilatant fluid 60 via the flexible bag 61. The dilatant fluid 60 then exerts a resistance force according to the speed of the shear force it receives.

The dilatant fluid 60 is disposed in the hollow portion i near the neck portion 34 of the shaft 2. In a more preferred embodiment, the dilatant fluid 60 is disposed in at least a portion of a range 100 mm upward from the upper end surface 34a of the neck portion 34 in the axial direction of the shaft 2. Since this range is an area where the shaft 2 is likely to return to its original shape when hitting a ball, a golf club 1 in which the dilatant fluid 60 is disposed in at least a portion of this range can more effectively suppress return to its original shape, thereby increasing the flight distance of the ball.

Next, more detailed embodiments of the present invention will be described.
As Example 1, a wood type golf club of the embodiment shown in Figure 1 was prototyped. The height L of the support part was 15 mm, and the forming range θ was 180°. The support part and the shaft were not bonded. The gap was 0 mm. Example 2 was based on Example 1, but a gap of 1 mm was formed between the support part and the shaft. The comparative example was Example 1 without the support part. All golf clubs had the same shaft.

Next, each golf club was attached to a swing robot, and a hitting test was conducted in which a golf ball was hit 10 times with a head speed of 42 m/s. When the average value of the flight distance of the ball hit with each golf club was examined, it was confirmed that Example 1 had improved by 0.5% and Example 2 had improved by 0.25% compared to the comparative example.

1 Golf club 2 Shaft 3 Golf club head 4 Support portion 5 Ferrule 5A Front portion 5B Rear portion 34 Neck portion 60 Dilatant fluid 61 Bag i Hollow portion of shaft

Claims (8)

A golf club,
A shaft,
a golf club head having a neck portion into which the shaft is inserted;
a support portion protruding from the neck portion toward the top of the head on a head rear side of the neck portion ,
When the golf club is in a stationary state, the support portion is spaced apart from the shaft .
Golf club. A golf club,
A shaft,
a golf club head having a neck portion into which the shaft is inserted;
A ferrule attached to the neck portion;
a support portion protruding from the ferrule toward above the head on a rear side of the head of the ferrule ,
When the golf club is in a stationary state, the support portion is spaced apart from the shaft .
Golf club. The golf club according to claim 1 or 2, wherein the support portion has a height of 5 mm or more along the axial direction of the shaft. A golf club according to any one of claims 1 to 3, wherein the support portion is curved along the outer surface of the shaft. 5. The golf club according to claim 1, wherein the support portion is formed in a range of 30 degrees or more around a center line of the shaft in a cross section perpendicular to an axial direction of the shaft . A golf club,
A shaft,
a golf club head having a neck portion into which the shaft is inserted;
a ferrule attached to the neck portion,
The ferrule includes a front portion located on the front side of the head and a rear portion located on the rear side of the head,
The rigidity of the rear side portion is greater than the rigidity of the front side portion.
Golf club. The golf club according to claim 6 , wherein the thickness of the rear side portion is greater than the thickness of the front side portion. 8. The golf club according to claim 6, wherein the Young's modulus of the rear side portion is greater than the Young's modulus of the front side portion.

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